CA1286011C - Electrical outlet receptacle with non-metallic mounting strap and automatic grounding - Google Patents
Electrical outlet receptacle with non-metallic mounting strap and automatic groundingInfo
- Publication number
- CA1286011C CA1286011C CA000557925A CA557925A CA1286011C CA 1286011 C CA1286011 C CA 1286011C CA 000557925 A CA000557925 A CA 000557925A CA 557925 A CA557925 A CA 557925A CA 1286011 C CA1286011 C CA 1286011C
- Authority
- CA
- Canada
- Prior art keywords
- grounding
- electrical
- cover member
- electrical outlet
- ground
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
- H01R13/648—Protective earth or shield arrangements on coupling devices, e.g. anti-static shielding
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
- H01H9/12—Means for earthing parts of switch not normally conductively connected to the contacts
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
Abstract
ABSTRACT
An electrical outlet receptacle device for mounting adjacent a wall member having a hole therein so that the device can be secured to an electrical outlet box mounted behind the wall member, the device has a receptacle body member for receiving and retaining electrical terminal/
contact assemblies to be terminated to the conductors of an electrical power cable and to electrically mate with the blades of an electrical connecting plug; a cover member adapted to be affixed to the body member, and having apertures formed therein for permitting insertion of the plug blades for mating with the terminal/contact assemblies and the cover member having a pair of mounting strap elements formed integrally therewith and projecting from opposite ends of the cover member; the mounting strap elements terminate in free end edges which are elongated to the maximum possible length to fit under a wallplate intended for use with the device, such that when the receptacle is mounted adjacent the wall opening, the probability that the mounting strap elements will abut the wall member is maximized so as to substantially reduce the chance of having a "floating" installation; the structure reduces fabrication and installation costs and breakages associated with prior structures.
An electrical outlet receptacle device for mounting adjacent a wall member having a hole therein so that the device can be secured to an electrical outlet box mounted behind the wall member, the device has a receptacle body member for receiving and retaining electrical terminal/
contact assemblies to be terminated to the conductors of an electrical power cable and to electrically mate with the blades of an electrical connecting plug; a cover member adapted to be affixed to the body member, and having apertures formed therein for permitting insertion of the plug blades for mating with the terminal/contact assemblies and the cover member having a pair of mounting strap elements formed integrally therewith and projecting from opposite ends of the cover member; the mounting strap elements terminate in free end edges which are elongated to the maximum possible length to fit under a wallplate intended for use with the device, such that when the receptacle is mounted adjacent the wall opening, the probability that the mounting strap elements will abut the wall member is maximized so as to substantially reduce the chance of having a "floating" installation; the structure reduces fabrication and installation costs and breakages associated with prior structures.
Description
BAChGROUND AND OBJECTS OF THE II~VENTION
1 The present invention relates generally to electri-2 cal wiring devices, and, more particularly, to electrical 3 outlet receptacle devices of improved construction, having 4 an automatic grounding system for grounding the device to a ~rounded electrical outlet box without requiring a metallic mounting strap and improved mounting means for ensuring 7 proper mounting of the device adjacent an opening formed in 8 a wall member.
g Electrical outlet receptacles for residential, hos-pital and industrial use are well known in the art. Hospi-11 tal and industrial grades of receptacles are often made in 1~ specialized configurations or with heavy duty features in 13 order to satisfy various code requirements (e.g., Under-14 writers' Laboratories Hospital Grade Test Program).
~esidential grade receptacles, on the other hand, are lo ganerally required to satisfy somewhat less stringent U.L.
1~ ~^equirements and have been manufactured for years with 18 little or no design changes so as to sell at the lowest possible cost. For example, residential grade outlet recep-tacles are often made with a body and cover member made from ~1 a thermo-set material using the same type of compression molds which have been in use for decades. These devices 23 also incorporate steel mounting straps which require 24 separate copper alloy ground contacts for mating with the ground prong of a plug inserted into the device.
Although known prior receptacle devices have pro-vided generally satisfactory results over the years, they do suffer severa] disadvant~aes. For example. the typically used thermo-set materials are relatively brittle and are susceptible to craching or breakage during fabrication or . .
installation. In addition, the metal mounting strap (which ~ is either sandwiched between the receptacle body and cover -~ or wrapped around the device~ is also a source for addi-tional fabrication, assembly and handling problems. For n~ple, the mounting straps are typically made of steel Q ~hich is susceptible to corrosion. In addition, the strap ? is easily deformed during fabrication and handling. More-over, steel straps cannot directly form the ground contacts for a receptacle. Rather, separate grounding contacts made la o~ the proper copper alloy material must be electrically 11 connected to the mounting strap, either by riveting or 1~ pressure fitting. This necessarily involves additional 1~ p~rts and additional fabrication steps which contribute to i4 the overall fabrication costs of the devices. The steel 1~ strap also requires a secondary tapping operation for co~modating the wall plate mounting screw.
17 ~ The assembly method of these devices is a further i~ source of problems. The body and cover, with the mounting strap held between them, are usually secured together by a astening rivet or screw-like fastener which is inserted ~i through the back of the receptacle body, through a clearance hole formed in the mounting strap and then force fit in a hole formed in the receptacle cover. To insure adequate -holding pot~er, close tolerances are required between the outer diameter of the rivet or screw-like fastener and the holes in the receptacle body and cover. Thus, if blisters are formed in the vicinity of these holes during molding or if the parts are warped in that vicinity, the resultant parts are susceptible to cracking when the fastner is installed. Further, since the only means of securing the , ' '. . ~ ' - parts together is the rlvet or screw fastener, the attach-- ~ent of the cover and body is vulnerable to loosening, -~ resulting in a dangerous intermittant condition in, or total disconnection of, the electrical connections within the device.
A significant breakage problem has also been experienced in the course of installing receptacles. One common construction practice involves "dealing out" indi~i-~ dual receptacles at each specific location where a recepta-1~ cle is to be installed by actually dropping them onto the 11 floor. Because of the brittle nature of the thermo-set materials used in the devices, the receptacles are susceptible to cracXing or breakage (with the attendant loosening or disconnection of electrical connections) when they are handled in such fashion. Also, breakage can occur in normal usage after installation when, e.g., a user pulls ~, on tha electrical cable to remove the plug at some distance i~ ~rom the receptacle itself. Although thermo-plastic materi-i~ als could be used to forln the receptacle body and cover and ~,~ reduce some of the breakage problems, they tend to be rela-tively expensive and, in any event, the mere substitution of .~ materials would not eliminate the other drawbacks described _ _ herein.
.~ Another disadvantage of conventional electrical outlet receptacles is the problem encountered when the wall opening cut to receive the receptacle is too large for one or both ends of the mounting strap to bear against the wall surface when the device is mounted to an electricai outlet ~ .
zox behind the wall. To compensate, electricians often rely ~- on the wall plate mounting screw to hold the receptacle in place. Such installation results in what is called a - "floating" installation, wherein the device mounting screws are not tightened all the way so the device can "float"
relative to the outlet box. The only means for bracing the outlat receptacle against the inward force of insertion of a 6 pl~l~ is the single wall plate mounting screw. (In a proper installation, of course, both ends of the mounting strap sho~lld abut the wall to brace the receptacle against the ~ inward force of plug insertion.) 10Such "floating" installations are undesirable 11 bacause they require extra installation time. The electri-1~ cian must judge how far to tighten down the mounting screws 1~ to ~ccommodate the wallplate, yet allow enough slack to pull 14 the device back against the wallplate. In addition, where `~ ~on-metallic wall plates are used (particularly those 1~ commonly made of phenolic or urea), the wallplate can be acked or broken by repeated insertion of plugs in a ~loating" receptacle installation, since the force of 1~ insertion of the plug is sustained only by the wallplate sc:raw .
It is therefore an object of the present invention to provide a new and improved electrical outlet receptacle ~hich overcomes the foregoing drawbacks and is of rugged construction and capable of economical fabrication, parti-cularly for residential grades. It is another object of the ~n invention to provide a new and improved electrical outlet aceptacle which can be fabricated essentially completely from thermo-plastic (including mo`unting strap portions) ,~ axcept for the electrical contacts/terminals and ground elements.
~8~
It is also an object of the invention to provide a ne~ and improved electrical outlet receptacle having mount-in~ means adapted to substantially reduce the possi-bility of "~loatin~" installations. In addition, it is an object of -~ tha invention to enable incorporation of such mounting 1~ faature in outlet receptacles for various sized wallplates.
It is also an object of the present invention to provide a new and improved electrical outlet receptacle g having a grounding system capable of automatically grounding 1~ the receptacle ~hen it is mounted to a grounded metal 11 electrical outlet box without requiring a metallic mounting 1~ strap and/or separate internal ground contacts to mate with 1~ the ~round prong of a plug. It is a further object of the 1~ invention to provide such a receptacle device which also 1~ incorporates alternate grounding means for direct termina-tion to the ground conductor of an electrical power cable. `
1~It is yet another object of the present invention i~ to provide an electrical outlet receptacle having a cover 1~ member and body which can be formed by simple two-part injection molding techniques. It is still another object of ~; the invention to provide such a receptacle having a mounting ~> strap formed integrally with the cover member to simplify _ _ fabrication and reduce the number of component parts for the complete device.
Further, it is an object of the present invention to provide a new and improved electrical outlet receptacle ~, capable of fully automated assembly by the use of component ~ parts which can be secured in place before the final ,~, assembly step. It is another object of the invention to 3~ provide such a receptacle device and method of assembly '~ which obviates the need for using the usual rivet or scre~-- type fastener yet forms a securely assembled receptacle 3 device.
Objects and advantages of the invention are set ~orth in part herein and in part will be apparent herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the structures, instrumentalities and combinations pointed out in the ~ appended claims. Accordingly, the invention resides in the novel parts, structures, arrangements, combinations, and 11 improvements herein shown and described.
1 .
1~ SUM~RY OF INVENTION
1~ Briefly described, the electrical outlet receptacle 1~ device according to the present invention includes a recep-l~ tacle housing which comprises a body member having electri-1~ cal terminal~contact members retained therein and a cover 1~ member attached to the body member and providing plug blade ~a access means to the electrical contacts within the recepta-3 1 cle device. According to one aspect of the invention, the cover member includes a pair of mounting strap elements formed integrally therewith and projectin~ from opposite ends of the cover member. In addition, the resultant ~3 integral mounting strap is elongated to the maximum length which ~ill fit under a wallplate intended for use with the receptacle device. Advantageously and as preferably embodied, the extreme end edges of the mounting strap ',3~ elements are beveled to maximize the elongation of the 3~ mounting strap while still enabling the receptacle to fit . . ~ , ~ completely under the lip of the ~allplate. Also advan-- tageously, the mounting strap elements are generally -~ squared-off to further increase the available surface area -for abutting the wall surface adjacent the hole in which the ~ receptacle is received when mounted to an electrical outlet 6 box behind that wall.
i According to another specific aspect of the inven-8 tion, grounding means are provided for automatically ground-~ ing the receptacle when mounted to a grounded electrical 1 a outlet box without requiriny the usual steel mounting 11 strap. As preferably embodied, the grounding means com-i~ prises a unitary grounding element made in the form of a l~ relatively elongate strip of electrically conductive l_ material, preferably a copper alloy. The grounding element 1~ includes two segments formed into a pair of grounding 1~ cont~cts positioned adjacent each access aperture for the i, ~round prong of a plug. The grounding element also includes l~ a pair of spring fingers formed integrally therewith at one 1~ ~nd. The spring fingers are adapted to extend through one o~ the appertures formed in the mounting strap elements for ~ receiving the device mounting screws. When the mounting 2~ screw is inserted between the spring fingers and threaded into the mounting lug of the grounded electrical outlet box, a continuous electrically conductive path is provided from the grounded outlet box through the mounting screw, thence .~ through the pair of spring fingers, along the grounding ~, element to each pair of ground contacts within the recep-tacle device. Also advantageously, the device is adapted to permit direct termination of a ground conductor to the device by an additional ground member press fit into ~36~
electrical contact with the grounding element and having a ~ro~nd terminal screw for direct termination to the ground ^, conductor.
It will be readily appreciated by those skilled in the art that the invention as disclosed and claimed herein aohiaves the objects and advantages specifically recited - herein~ For example, by forming the cover member with integral mounting strap elements, the overall fabrication ~ costs and handling of parts will be substantially reduced.
1~ In addition, by elongating the integrally formed mounting 11 strap elements in accordance with the present disclosure, 1~ the possibility of having a "floating" installation of the 1~ ~evice is greatly reduced.
1 By providing the unitary grounding element having t'~70 sets of electrical ground contacts and a pair of spring 1~ fi~ e.rs extending through one of the mounting screw aper-res for the device, it will be found that the receptacle IR accor~ing to the invention c~n be automatically grounded to 1~ a pre-grounded electrical outlet box without requiring the ~ usual steel mounting strap. In addition, the unitary 'i ~rounding element according to the invention reduces the total number and size of parts rsquired for assembly of the device, thereby eliminating the costs associated with the -fabrication and handling of such additional parts. The ~ qrounding element according to the invention is substan-~ tially shorter, thinner and lighter than the conventional ~_ ~teel mounting strap and it is much easier to form and tohandle during assembly, and, it eliminates the need for providing separate copper alloy ground contacts for the device.
Ç
~36~
- Also, by providing the additional ground member - which is in electrical communication with the grounding element accordiny to the invention, the device is ~lso capable of being directly terminated to the ground conducter of an electrical power cable. In addition, the press fit contact between the additional ground member and the , grounding element, as disclosed more specifically 8 hereinafter, obviates the need for riveting or welding of c the ground ~erminal members within the device.
It should be understood that the foregoing general ll description and the followinq detailed description are i' exemplary and explanatory of the invention, but are not 13 intended to be restrictive thereof or to be exhaustive of 1~ the advantages which can be achieved by the invention.
,~ The accompanying drawings, referred to herein, and 1~ constituting a part hereof, illustrate a preferred embodi-1, m~nt of the invention, and, when taken together with the i~ following detailed description, serve to illustrate the I~J principles and advantages of the invention.
~a ~i BRIEF DESCRIPTION_OF DRAWINGS
FIGURE l is a perspective view, from the front side, of a preferred embodiment of an electrical outlet receptacle device according to the present invention.
FIGURE 2 is a front elevation view of the electrical outlet receptacle of FIGURE l.
~ FIGURE 3 is a sidé elevation view of the right si~e '? of the electrical outlet receptacle as shown in FIGURE l.
FIGURE 4 is an e~ploded perspective view, from the same angle as FIGURE 1, of the electrical outlet receptacle device shown in FIGURE 1.
FIGURE 5 is a plan view of the back side of the cover member of the electrical receptacle of the present -~ invention.
b FIGURE 6 is a plan vie~ of the interior of the body portion of the electrical outlet receptacle shown in FIGURE
ith the internal electrical contact/terminals in place.
c FIGURE 7 is a plan view of the cover member, 1~ similar to that of FIGURE 5, showing how the grounding 11 element of FIGURE 8 is pre-loaded onto the cover member in 1~ preparation ~or assembly of the receptacle in accordance 1~ t~ith the invention.
1~ FI~URE 8 is a top plan view of the grounding 1~ element according to the present invention 1~ FIGURE 9 is a side view of the grounding element own in FIGURE 8.
FIGURE 10 is a sectional view taken along line 1~ 10-10 of the grounding element shown in FIGURE 8.
~ FIGURE 11 is a sectional view taken alcng line -.i 11-11 of the grounding element shown in FIGURE 8.
~2 DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Referring now to the embodiment of the invention -?,~ illu~trated .in the accompanylng drawings, wherein like ~; reference characters refer to like parts through~ut the VAriOUS views, there is shown ln ~ R~ 1 a preferred embodiment of an electrical outlet receptacle, and i~s -- 1 0 -- , ~ "
component parts, ~hich incorporates the various features - according to the present invention.
3 Referring more particularly to FIGURES 1-4-, there - are shown various views of the electrical outlet receptacle S of the present invention (indicated generally by reference n~m~eral 10), which generally includes, when fully assembled, a housing made up of body member 12 and cover member 14 which carries mounting strap elements 15 and 16 for mounting q the receptacle to an electrical outlet box (not shown) which is supported behind an opening in a wall member. Cover member 14 is provided with two plug receiving face portions ~each indicated at 18), each of which has a pair of 1' apartures 19 and 20 for receiving the blades of a plug (not ~4 shown) and a third aperture 21 for receiving the ground 1~ prong of the plug. Cover member 14 also includes an 1~ ~pperture 41 for receiving a wall plate mounting screw ~not 1~ shown) as will be described more fully below.
i~ For ease of fabrication and durability of parts, 1~ cover member 14 and body 12 are preferrably constructed of ~?a an injection moldable thermo-plastic material and mounting strap elements 15 and 16 are formed integrally with the cover member 14 in a unitary structure. Any injection moldable thermo-plastic material acceptable for use in electrical wiring devices can be used, provided it satisfies the necessary flame, impact and other electrical and ~b mechanical property tests required by Underwriters' Labora~
tories or any other applicable code. Examples of such ~, acceptable ~aterials include polyvinyl chloride, polycarbo--~ nates, ny~lon, etc., and/or blends of such materials which are formulated for good impact strengt~l, good molding l~B~
characteristics and low cost, particularly the polyvinyl chloride based composition formulated by Georgia Gulf corp.
for Slater ElPctric Inc. and designated "TECHNALLOY" by Slater Electric.
As here embodied, body member 12 is constructed so as to receiva and retain a pair of electrical contact/
1 The present invention relates generally to electri-2 cal wiring devices, and, more particularly, to electrical 3 outlet receptacle devices of improved construction, having 4 an automatic grounding system for grounding the device to a ~rounded electrical outlet box without requiring a metallic mounting strap and improved mounting means for ensuring 7 proper mounting of the device adjacent an opening formed in 8 a wall member.
g Electrical outlet receptacles for residential, hos-pital and industrial use are well known in the art. Hospi-11 tal and industrial grades of receptacles are often made in 1~ specialized configurations or with heavy duty features in 13 order to satisfy various code requirements (e.g., Under-14 writers' Laboratories Hospital Grade Test Program).
~esidential grade receptacles, on the other hand, are lo ganerally required to satisfy somewhat less stringent U.L.
1~ ~^equirements and have been manufactured for years with 18 little or no design changes so as to sell at the lowest possible cost. For example, residential grade outlet recep-tacles are often made with a body and cover member made from ~1 a thermo-set material using the same type of compression molds which have been in use for decades. These devices 23 also incorporate steel mounting straps which require 24 separate copper alloy ground contacts for mating with the ground prong of a plug inserted into the device.
Although known prior receptacle devices have pro-vided generally satisfactory results over the years, they do suffer severa] disadvant~aes. For example. the typically used thermo-set materials are relatively brittle and are susceptible to craching or breakage during fabrication or . .
installation. In addition, the metal mounting strap (which ~ is either sandwiched between the receptacle body and cover -~ or wrapped around the device~ is also a source for addi-tional fabrication, assembly and handling problems. For n~ple, the mounting straps are typically made of steel Q ~hich is susceptible to corrosion. In addition, the strap ? is easily deformed during fabrication and handling. More-over, steel straps cannot directly form the ground contacts for a receptacle. Rather, separate grounding contacts made la o~ the proper copper alloy material must be electrically 11 connected to the mounting strap, either by riveting or 1~ pressure fitting. This necessarily involves additional 1~ p~rts and additional fabrication steps which contribute to i4 the overall fabrication costs of the devices. The steel 1~ strap also requires a secondary tapping operation for co~modating the wall plate mounting screw.
17 ~ The assembly method of these devices is a further i~ source of problems. The body and cover, with the mounting strap held between them, are usually secured together by a astening rivet or screw-like fastener which is inserted ~i through the back of the receptacle body, through a clearance hole formed in the mounting strap and then force fit in a hole formed in the receptacle cover. To insure adequate -holding pot~er, close tolerances are required between the outer diameter of the rivet or screw-like fastener and the holes in the receptacle body and cover. Thus, if blisters are formed in the vicinity of these holes during molding or if the parts are warped in that vicinity, the resultant parts are susceptible to cracking when the fastner is installed. Further, since the only means of securing the , ' '. . ~ ' - parts together is the rlvet or screw fastener, the attach-- ~ent of the cover and body is vulnerable to loosening, -~ resulting in a dangerous intermittant condition in, or total disconnection of, the electrical connections within the device.
A significant breakage problem has also been experienced in the course of installing receptacles. One common construction practice involves "dealing out" indi~i-~ dual receptacles at each specific location where a recepta-1~ cle is to be installed by actually dropping them onto the 11 floor. Because of the brittle nature of the thermo-set materials used in the devices, the receptacles are susceptible to cracXing or breakage (with the attendant loosening or disconnection of electrical connections) when they are handled in such fashion. Also, breakage can occur in normal usage after installation when, e.g., a user pulls ~, on tha electrical cable to remove the plug at some distance i~ ~rom the receptacle itself. Although thermo-plastic materi-i~ als could be used to forln the receptacle body and cover and ~,~ reduce some of the breakage problems, they tend to be rela-tively expensive and, in any event, the mere substitution of .~ materials would not eliminate the other drawbacks described _ _ herein.
.~ Another disadvantage of conventional electrical outlet receptacles is the problem encountered when the wall opening cut to receive the receptacle is too large for one or both ends of the mounting strap to bear against the wall surface when the device is mounted to an electricai outlet ~ .
zox behind the wall. To compensate, electricians often rely ~- on the wall plate mounting screw to hold the receptacle in place. Such installation results in what is called a - "floating" installation, wherein the device mounting screws are not tightened all the way so the device can "float"
relative to the outlet box. The only means for bracing the outlat receptacle against the inward force of insertion of a 6 pl~l~ is the single wall plate mounting screw. (In a proper installation, of course, both ends of the mounting strap sho~lld abut the wall to brace the receptacle against the ~ inward force of plug insertion.) 10Such "floating" installations are undesirable 11 bacause they require extra installation time. The electri-1~ cian must judge how far to tighten down the mounting screws 1~ to ~ccommodate the wallplate, yet allow enough slack to pull 14 the device back against the wallplate. In addition, where `~ ~on-metallic wall plates are used (particularly those 1~ commonly made of phenolic or urea), the wallplate can be acked or broken by repeated insertion of plugs in a ~loating" receptacle installation, since the force of 1~ insertion of the plug is sustained only by the wallplate sc:raw .
It is therefore an object of the present invention to provide a new and improved electrical outlet receptacle ~hich overcomes the foregoing drawbacks and is of rugged construction and capable of economical fabrication, parti-cularly for residential grades. It is another object of the ~n invention to provide a new and improved electrical outlet aceptacle which can be fabricated essentially completely from thermo-plastic (including mo`unting strap portions) ,~ axcept for the electrical contacts/terminals and ground elements.
~8~
It is also an object of the invention to provide a ne~ and improved electrical outlet receptacle having mount-in~ means adapted to substantially reduce the possi-bility of "~loatin~" installations. In addition, it is an object of -~ tha invention to enable incorporation of such mounting 1~ faature in outlet receptacles for various sized wallplates.
It is also an object of the present invention to provide a new and improved electrical outlet receptacle g having a grounding system capable of automatically grounding 1~ the receptacle ~hen it is mounted to a grounded metal 11 electrical outlet box without requiring a metallic mounting 1~ strap and/or separate internal ground contacts to mate with 1~ the ~round prong of a plug. It is a further object of the 1~ invention to provide such a receptacle device which also 1~ incorporates alternate grounding means for direct termina-tion to the ground conductor of an electrical power cable. `
1~It is yet another object of the present invention i~ to provide an electrical outlet receptacle having a cover 1~ member and body which can be formed by simple two-part injection molding techniques. It is still another object of ~; the invention to provide such a receptacle having a mounting ~> strap formed integrally with the cover member to simplify _ _ fabrication and reduce the number of component parts for the complete device.
Further, it is an object of the present invention to provide a new and improved electrical outlet receptacle ~, capable of fully automated assembly by the use of component ~ parts which can be secured in place before the final ,~, assembly step. It is another object of the invention to 3~ provide such a receptacle device and method of assembly '~ which obviates the need for using the usual rivet or scre~-- type fastener yet forms a securely assembled receptacle 3 device.
Objects and advantages of the invention are set ~orth in part herein and in part will be apparent herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the structures, instrumentalities and combinations pointed out in the ~ appended claims. Accordingly, the invention resides in the novel parts, structures, arrangements, combinations, and 11 improvements herein shown and described.
1 .
1~ SUM~RY OF INVENTION
1~ Briefly described, the electrical outlet receptacle 1~ device according to the present invention includes a recep-l~ tacle housing which comprises a body member having electri-1~ cal terminal~contact members retained therein and a cover 1~ member attached to the body member and providing plug blade ~a access means to the electrical contacts within the recepta-3 1 cle device. According to one aspect of the invention, the cover member includes a pair of mounting strap elements formed integrally therewith and projectin~ from opposite ends of the cover member. In addition, the resultant ~3 integral mounting strap is elongated to the maximum length which ~ill fit under a wallplate intended for use with the receptacle device. Advantageously and as preferably embodied, the extreme end edges of the mounting strap ',3~ elements are beveled to maximize the elongation of the 3~ mounting strap while still enabling the receptacle to fit . . ~ , ~ completely under the lip of the ~allplate. Also advan-- tageously, the mounting strap elements are generally -~ squared-off to further increase the available surface area -for abutting the wall surface adjacent the hole in which the ~ receptacle is received when mounted to an electrical outlet 6 box behind that wall.
i According to another specific aspect of the inven-8 tion, grounding means are provided for automatically ground-~ ing the receptacle when mounted to a grounded electrical 1 a outlet box without requiriny the usual steel mounting 11 strap. As preferably embodied, the grounding means com-i~ prises a unitary grounding element made in the form of a l~ relatively elongate strip of electrically conductive l_ material, preferably a copper alloy. The grounding element 1~ includes two segments formed into a pair of grounding 1~ cont~cts positioned adjacent each access aperture for the i, ~round prong of a plug. The grounding element also includes l~ a pair of spring fingers formed integrally therewith at one 1~ ~nd. The spring fingers are adapted to extend through one o~ the appertures formed in the mounting strap elements for ~ receiving the device mounting screws. When the mounting 2~ screw is inserted between the spring fingers and threaded into the mounting lug of the grounded electrical outlet box, a continuous electrically conductive path is provided from the grounded outlet box through the mounting screw, thence .~ through the pair of spring fingers, along the grounding ~, element to each pair of ground contacts within the recep-tacle device. Also advantageously, the device is adapted to permit direct termination of a ground conductor to the device by an additional ground member press fit into ~36~
electrical contact with the grounding element and having a ~ro~nd terminal screw for direct termination to the ground ^, conductor.
It will be readily appreciated by those skilled in the art that the invention as disclosed and claimed herein aohiaves the objects and advantages specifically recited - herein~ For example, by forming the cover member with integral mounting strap elements, the overall fabrication ~ costs and handling of parts will be substantially reduced.
1~ In addition, by elongating the integrally formed mounting 11 strap elements in accordance with the present disclosure, 1~ the possibility of having a "floating" installation of the 1~ ~evice is greatly reduced.
1 By providing the unitary grounding element having t'~70 sets of electrical ground contacts and a pair of spring 1~ fi~ e.rs extending through one of the mounting screw aper-res for the device, it will be found that the receptacle IR accor~ing to the invention c~n be automatically grounded to 1~ a pre-grounded electrical outlet box without requiring the ~ usual steel mounting strap. In addition, the unitary 'i ~rounding element according to the invention reduces the total number and size of parts rsquired for assembly of the device, thereby eliminating the costs associated with the -fabrication and handling of such additional parts. The ~ qrounding element according to the invention is substan-~ tially shorter, thinner and lighter than the conventional ~_ ~teel mounting strap and it is much easier to form and tohandle during assembly, and, it eliminates the need for providing separate copper alloy ground contacts for the device.
Ç
~36~
- Also, by providing the additional ground member - which is in electrical communication with the grounding element accordiny to the invention, the device is ~lso capable of being directly terminated to the ground conducter of an electrical power cable. In addition, the press fit contact between the additional ground member and the , grounding element, as disclosed more specifically 8 hereinafter, obviates the need for riveting or welding of c the ground ~erminal members within the device.
It should be understood that the foregoing general ll description and the followinq detailed description are i' exemplary and explanatory of the invention, but are not 13 intended to be restrictive thereof or to be exhaustive of 1~ the advantages which can be achieved by the invention.
,~ The accompanying drawings, referred to herein, and 1~ constituting a part hereof, illustrate a preferred embodi-1, m~nt of the invention, and, when taken together with the i~ following detailed description, serve to illustrate the I~J principles and advantages of the invention.
~a ~i BRIEF DESCRIPTION_OF DRAWINGS
FIGURE l is a perspective view, from the front side, of a preferred embodiment of an electrical outlet receptacle device according to the present invention.
FIGURE 2 is a front elevation view of the electrical outlet receptacle of FIGURE l.
~ FIGURE 3 is a sidé elevation view of the right si~e '? of the electrical outlet receptacle as shown in FIGURE l.
FIGURE 4 is an e~ploded perspective view, from the same angle as FIGURE 1, of the electrical outlet receptacle device shown in FIGURE 1.
FIGURE 5 is a plan view of the back side of the cover member of the electrical receptacle of the present -~ invention.
b FIGURE 6 is a plan vie~ of the interior of the body portion of the electrical outlet receptacle shown in FIGURE
ith the internal electrical contact/terminals in place.
c FIGURE 7 is a plan view of the cover member, 1~ similar to that of FIGURE 5, showing how the grounding 11 element of FIGURE 8 is pre-loaded onto the cover member in 1~ preparation ~or assembly of the receptacle in accordance 1~ t~ith the invention.
1~ FI~URE 8 is a top plan view of the grounding 1~ element according to the present invention 1~ FIGURE 9 is a side view of the grounding element own in FIGURE 8.
FIGURE 10 is a sectional view taken along line 1~ 10-10 of the grounding element shown in FIGURE 8.
~ FIGURE 11 is a sectional view taken alcng line -.i 11-11 of the grounding element shown in FIGURE 8.
~2 DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Referring now to the embodiment of the invention -?,~ illu~trated .in the accompanylng drawings, wherein like ~; reference characters refer to like parts through~ut the VAriOUS views, there is shown ln ~ R~ 1 a preferred embodiment of an electrical outlet receptacle, and i~s -- 1 0 -- , ~ "
component parts, ~hich incorporates the various features - according to the present invention.
3 Referring more particularly to FIGURES 1-4-, there - are shown various views of the electrical outlet receptacle S of the present invention (indicated generally by reference n~m~eral 10), which generally includes, when fully assembled, a housing made up of body member 12 and cover member 14 which carries mounting strap elements 15 and 16 for mounting q the receptacle to an electrical outlet box (not shown) which is supported behind an opening in a wall member. Cover member 14 is provided with two plug receiving face portions ~each indicated at 18), each of which has a pair of 1' apartures 19 and 20 for receiving the blades of a plug (not ~4 shown) and a third aperture 21 for receiving the ground 1~ prong of the plug. Cover member 14 also includes an 1~ ~pperture 41 for receiving a wall plate mounting screw ~not 1~ shown) as will be described more fully below.
i~ For ease of fabrication and durability of parts, 1~ cover member 14 and body 12 are preferrably constructed of ~?a an injection moldable thermo-plastic material and mounting strap elements 15 and 16 are formed integrally with the cover member 14 in a unitary structure. Any injection moldable thermo-plastic material acceptable for use in electrical wiring devices can be used, provided it satisfies the necessary flame, impact and other electrical and ~b mechanical property tests required by Underwriters' Labora~
tories or any other applicable code. Examples of such ~, acceptable ~aterials include polyvinyl chloride, polycarbo--~ nates, ny~lon, etc., and/or blends of such materials which are formulated for good impact strengt~l, good molding l~B~
characteristics and low cost, particularly the polyvinyl chloride based composition formulated by Georgia Gulf corp.
for Slater ElPctric Inc. and designated "TECHNALLOY" by Slater Electric.
As here embodied, body member 12 is constructed so as to receiva and retain a pair of electrical contact/
7 terminal assemblies (each indicated generally at 22) which are of generally conventional configuration and need not be ~ described in great detail. In general, each contact/
1~ terminal assembly comprises a unitary structure which 11 incl~des two pairs of contact members (24, 25) adapted to 1~ ~rasp the blades of a plug and a pair of terminal portions ~each indicated at 23) which are connected together by a 14 bridging portion (each indicated at 23A). The terminal - l~ members include threaded holes for receiving termination 1~ screws (each indicated at 30) which are thus accessible from 1~, the exterior of the body.
l~ As here embodied, body 12 is made up of a bottom 1~ wall with a pair of oppositely disposed sidewalls and a palr o~ oppositely disposed endwalls upstanding from the bottom ~all~ The body includes several upstanding interior walls ~2 to define, e.g., the slots or co~partments for receiving the electrical contact/terminal assemblies 22 as well as several guidance pins (e.g., indicated at 17) to heIp align the ~ cover and body during the final assembly step~ However, ~ since many of these internal body structures are of 2~ generally conventional configuratlon, they need not be ~ described in great deta~ niy tnose structures which will ,~ facilitate an understanding of the various features of the 3~ present invention will be mentioned in detail hereinafter.
Referring particularly to FIGURES 4, 5 and 7, the preferred integral formation of cover member 14 and mounting strap elements 15 and 16 will be more apparent. As-indicated above, in accordance with the invention and in `~ order to reduce the number of parts and manufacturing costs, 6 the l-eceptacle mounting strap is molded integrally with ~ ~over member 14 in the form of mounting strap elements 15, 1~ e~tending from opposite ends of the device cover. Each ~ mo~nting strap elèment includes an aperture (lSA, 16A) 1~ proportioned to receive the device mounting screw. As will 11 be described kelow, at least one of the apertures is adapted J ' ~0 achieve automatic grounding of the receptacle to a 3 ~rounded electrical outlet box in accordance with the ~ invention.
- '~ Advantageously and as preferably embodied, the 1~ ~nounting strap elements are formed such that the overall langth o~ the device, as measured from their extreme opposite ends, is increased relative to the overall length o~ conventional steel mounting straps. Preferably, the ,~ mounting strap elements extend to the maximum possible length that can be accommodated under the wallplate to be used with the device. According to the invention, in order to facilitate maximum elongation of mountlng strap portions 15 and 16, they are each advantageously provided with continuous beveled front end edges, 15B and 16B, respec-ti~ely, to fit under the end edges, or rim, of the wallplate (shown in phantom in FIGURE 3). For example, for standard si~e wallplates, the overall length of strap elements 15 and 1~ may be appro~:imately o.l to 0.125 inches longer than conventional steel straps, for a total overall length of about ~ 3/16 to about 4 1/4 inches.
3 It will be understood by those skilled in the art - that the integral mounting strap portions of the present ~ invention can be elongated even further for installations in o which larger wallplates are to be used. For example, the 7 strap can be approximately 3/8 inch longer (l.e., about 4 $ 9~16 to 4 5~8 inches) for use with wallplates sold under the g "SE~II JU~BO" designation by Slater Electric Inc., Glen Cove, 1~ New York. Figure 2 illustrates an embodiment of such 11 further elongation as further mounting strap elements 15c `L ~ and 16c which project from the end edges of mounting strap 1~ elements 15 and 16, respectively. Further strap elements 4 15c and 16c are preferably beveled at their end edges (as ~ indicated at 15d and 16d, respectively) to fit under a l~ wallplate substantially as described above in connection with beveled edges 15b and 16b. In addition, further ~ elemants 15c and 16c can be defined by notches 15e and 16e, 1~ respectively (similar to notchès 37 and 38 which are ?~ descried below), to form them as break-off tabs like tab 35 ~ and 36 descibed below.
22 It will be appreciated by those skilled in the art 3 that by maximizing the length of the strap elements, the ~4 maximum surface area is provided for ensuring that the strap .~ will abut some surface of a wall member when mounted to an outlet box. This arrangement will greatly reduce the possibility of a "floating" installation.
Also advantageously, strap elements 15 and 16 ~ extend at least as wide as (and preferably wider than) the 3~ width of the cover portion and they preferably include ~36~1~
-' s~uared-off side portions instead of the typical round - "ears" found on conventional steel mounting straps. The widened and squared-off side portions of the mounting strap elements are advantageous in that they further increase the -S total surface area available to abut some portion of the 6 w~ll member ln which the mounting hole is formed.
For use with special configuration outlet boxes whera the elongated mounting strap may be longer than '? desirad for the particular installation (e.g. for so-called "old ~ork" boxes or mobile home boxes), strap elements 15 1~ and 16 include break-off sections 35 and 36 (FIGURE 2) which n be snapped off along diagonally extending notches 37 and 13 38 and recessed portion 39, thus reducing the overall length f the mounting strap.
13 Referring now to FIGURES 4 and 8-11, there are shown the component parts of a pre~erred embodiment of the improved grounding system according to the invention. As here embodied, a relatively elongate grounding element (34) is provided in the ~orm of a bus bar type conductor which is located within the receptacle housing. Grounding element 34 ~i is a unitary member which may be stamped in side-by-side 2~ arrangement from a relatively thin, continuous metal strip made of copper alloy, to provide automatic grounding in a single unitary part. As here embodied, element 34 includes mounting head portion 50, stem portion 76, broadened stem portion 79, and a pair of ground contact portions 59 and 60 all formed in a unitary part. Head portion 50 is provided ith a ~enerally H-shaped aperture (indicated g-ener~ at ~?~ ~) to ~orm a pair of spring-like fingers ~55, 56) which are 3~- adapted to grasp a device mounting screw to provide the - automatic grounding according to the invention, as will be - d~scribed in greater detail hereinafter.
The resultant H-sha~ed aperture is thus surrounded by top edge 51, side edges 52 and 53 and connecting segment 5~l, leaving the cantilever-like fingers 55 and 56 extending towards each other from top edge 51 and connecting segment ~, respectively. As is evident from FIGURE 9, connecting se~ment 54 has a double bend, or a somewhat S-shape, for ~ l~cating contact head 50 in proper position adjacent the l~ mounting screw hole 15A. In addition, the H-shaped aperture 11 ~8 preferably extends through at least the uppermost bend of l_ connecting segment 54 and down to the second bend to provide 1~ increasad flexibility and spring action for fingers 55 and i~ 56~ Connecting segment 54 will thus consist of a solid 1~ sub-segment 54a with three separate upstanding connecting 16 sub-segments 54b, 54c and 54d. Sub-segments 54b and 54c ~, c~nnect side edges 52 and 53, respectively, to sub-segment ~,~ 54a, while sub-segment 54d connects finger 56 to sub-segment 1~ 5~a. As preferably embodied, the width of sub-segment 54d equals the total of the widths of sub-segments 54b and 54c.
~i It will thus be understood that, as a result, each finger 55 and 56 will be equally spring biased so that as a mounting screw is inserted between the fingers, the screw will be subjected to equal, but oppositely directed, spring forces by fingers 55 and 56.
Also advantageously, the ends of both fingers 55 and 56 are bent forward by about 90 to form a pair of prongs (55A and 5GA, respectively) which project outwardly ~ from head portion 50. The prongs are positioned to project 3~ through aperture 15A when the grounding element is located 12~6~
in place, and, advantageously, the distance between the two prongs should be at least slightly less than the diameter of the device mcunting screw so that it will be firmly grasped by the prongs and provide good electrical contact there-between. Also, as preferably embodied, the prongs 55A and ~6A are, themselves, bent back towards the rim of aperture ~ 15A to help secure, or pre-load, the grounding element onto the cover member 14, as indicated in phantom in FIGU~E 9.
~ According to the invention, electrical connection 1~ between ~he grounding prong of a typical 3-conductor 11 grounded plug (not shown) and receptacle 10 is established i~ through integrally formed ground contact portions 59 and 3 60. As here embodied, ground contact portions 59 and 60 are s~bstantially identical in that they are formed as a result ~- of a generally I-shaped aperture stamped into the grounding 1~ element 34, resulting in a pair of flanges (71, 72) which depend from the remaining side edges (63, 64, respectively) ~ ~ the grounding element, and are bent angularly inwardly so 1~ as to project downwardly toward each other, and into the ~,~ interior of body 12 when installed in the device, as will be ~vide.nt from the description below. The bent fingers thus ~2 provide an inwardly taperlng opening (indicated at 73) for receiving and contacting the grounding prong of an electrical plug when the plug is inserted into the assembled receptacle. The side edges 63, 64 may also be bent so as to ~e generally co-planar with flanges 71 and 72, thereby ~, providing an enlarged funnel-like opening for the ground prong.
Grounding element 34 is also advantageously provided with a pair of fingers (77, 78) which project ~2~36~
laterally outward from the grounding element for locating - element 34 in its desired position for the final assembly 3 operation. As here embodied, fingers 77, 78 are formed by notches 77A and 78A cut into broadened stem portion 79. The ~ ~in~ers are proportioned to be wedged against projections t) 101 and 102 ~described below) formed on the cover member 14 t~ help secure the grounding element 34 to the cover member along with the oppositely bent segments on prongs 55A and ~ 5~A, which secure terminal head portion 50 to the rim of 1~ aperture 15A. In this way, the grounding element is 11 pre-loaded to the cover member prior to assembly and will be l_ seated in proper position when the cover is placed over the 13 ra~aptacle body to facilitate automated assembly of the 1~ r~ceptacle device.
1~ Broadened stem portion 79 is also advantageously 1~ p~ovided with an aperture 80 proportioned to threadably 11 raceive a wall plate mounting screw in order to ground the ~ wallplate screw. The diameter of aperture 80 is preferably 1~ about equal to the interior thread diameter of the wall plate screw, and it includes a series of notches 80A (here, there are four such notches) formed symmetrically around ~2 aperture 80 to provide deformable thread-engaging fingers ~ (not numbered~. In use, as the wallplate mounting screw is threaded into aperture 80, these thread-engaging fingers will be deformed to conform to the helical pattern of the sc~ew threads and provide reliable grounding of the wall plate mounting screw to the device.
To facilitate threaded engagement between the wall ~ plate screw and aperture 80, body 12 is provided with hollow 3~ annular pillar 90 which is aligned with aperture 80 when the ~36~
device is fully assembled. The upper edge of pillar 90 supports ground element 34 in the vicinity surrounding aperture 80 during insertion of the wall plate screw. In ~ addition, the hollow pillar is preferably proportioned to S threadably receive the shank of the wallplate mounting screw hich is initially inserted through hole 41 in cover 14) , not only to protect it from inadvertent contact with or arc-over from the energized contact/terminals 22 but also to ~ hold the wallplate in place.
1~ Groundinq element 34 may also be formed to 11 auto~ati-cally ground the wallplate mounting screw when used 1' in a decorator style receptacle device. As shown in phantom ~, in FIGURE 8, head portion 50 may be formed with extended 1~ head portion 50A which includes a U-shaped slot 58A. When 1~ the decorator style device is assembled, slot 58A is 1~ positioned behind one of the wallplate mounting screw `
1, openings (similar to opening 41 formed on receptacle cover 1~ 14) ~ormed at either end of the the decorator receptacle 1~ ~a~a~ The width of slot 58A is preferably slightly less thall the outer thread diameter of the mounting screw. Thus, ~ i in view o~ the foregoing descriptions, it will be understood ? ~ that as the screw is threaded in slot 58A, it will thread-_ _ ~3 ably engage opposite sides of the slot, thereby causing them _~ to be distorted by the helical screw threads and assure goodelectrical contact between extended head portion 50A and the decorator-style wallplate mounting screw.
In use, the fully assembled receptacle 10 ~assembly ~ of the device in accordance with the invention will be ,~ described below) is mounted to an electrical outlet box ~ .
~ tJenerally in the usual way by inserting the device mounting ~ 19 -1~6~
scre~s (one is indicated at 7 ln FIGURE 4) through apertures l~ and 16A formed in mounting strap elements 15 and 16, 3 respectively. The screw inserted through aperture 15A is securely grasped between the pair of ~lared prongs 55A and 56A of groundinc3 element 34, forcing the prongs to flex outwardly towards the upper and lower edges of aperture 15A
hich can act as a limit for the outward flexure of the prongs). As a result, good electrical contact is maintained ~ between the mounting screw and the prongs 55A and 56A, and, therefol-e, with the entire grounding element 34.
ll In accordance with a principal advantage of the l~ invention, when the receptacle is mounted to a metallic alectrical outlet box that is already grounded, the 4 receptacle device itself will automatically be qrounded by ~ 1~ virtue of the continuous electrically conductive path 1~ a~tablished from the outlet box through the mounting screw, 1- through prongs 55A and 56A to grounding element 34 and i~ thence to the two ground con~act elements 59, 60. Thus, hen the ground prong of a plug is inserted through an aperture 21 in an outlet face member 18, the prong is ~i enc3ac3ed by, and forms electrical contact with, one of the pairs of spring-action flanges (71, 72) of the ground element, thereby grounding the electrical connection between the receptacle and the plug. To support ground contact ~ elements 59, 60 during inward insertion of the plug, body 12 ~ includes a hollow pier (each indicated at 82) located under each ground contacts 59, 60. It will also be understood ~ a~ piers ~ re~ei~e t-.e ground prong of the plug to ,J~ prevent inadvertent contact with, or arc-over from, any 31 enerc3ized contact/terminals 22 in the device.
.:
.: : .
~6~
~ As preferably embodied, device 10 is also provided - with means for grounding the receptacle by direct termina--~ tion to the ground conductor of an electrical power cable for installations wherein the outlet box is not grounded.
-S As here embodied, a portion of the end wall and the side wall at one corner of the receptacle body 12 is eliminated ~as indicated at 12c), except for a short lip 12d adjacent the bottom of body 12, and replaced by an L-shaped ground (~ 'cerminal 26 which also includes ground termination screw 32 1~ tllreadably engaged with terminal 26 for direct termination 11 to a ground conductor when needed. L-shaped ground terminal i ~ ~6 is advantageously retained in place inside lip 12d, both p ior to and during the assembly operation by a slot ndicated at 12e) formed along the body sidewall and a similal slot 12f formed between the body end wall and the adjacent hollow pier 82. Terminal 26 may also be maintained ~, in proper alignment by a tab 12g formed on the end wall which is adapted to engage notch 26A formed in terminal 26.
dvantageously and as preferably embodied, the body end ~,~ wall may extend substantially completely to the corner, as ~i indicated in phantom in FIGURE 4, for added wall strength ~-~ and to maximize the amount of material available for the preferred sonic welding assembly described hereinafter.) Terminal 26 preferably includes a pair of ground engaging studs (27, 28) which are positioned to correspond ~, in position with a pair of cante~ fingers (74, 75) formed on ground element 34 to provide electrical connection between ~, those two elements. Fingers 74 and 75 are canted (or formed ~_ at an angle) so as to flex when engaged by the studs 27 and 2~ on terminal 26, yet remain biased somewhat ayainst them, when installed in place to ensure good electrical mating between studs 27, 28 and fingers 74, 75.
-~ Thus, in the event the outlet box has not been grounded so as to take advantage of the automatic grounding provided by the present inve.ntion, the receptacle can still ba grounded by terminating the ground (green) conductor of an electrical power cable to the ground terminal screw 32 in substantially the same way as has been done heretofore. It ~ will be understood that by virtue of the good electrical 1~ contact provided between studs 27, 28 on ground terminal 26 11 and the canted fingers 74, 75 formed on ground element 34, i~ an alternate continuous ground path is provided via terminal 1~ screw 32, through ground terminal 26 and grounding element 1~ 34- Thus, when the ground conductor is terminated to screw 1~ 32, the receptacle outlets are grounded through the same 1~ qrounding element 34 that provides the automatic grounding l/ capability.
i~ Referring now to FIGURE 6, the interior configura-1~ tion of body 12 is shown, with the internal terminal/contact ~a mambers ~2 installed therein. As previously indicated, a 'i pair of raised hollow piers 82 extend upwardly from the bottom of body 12 to support ground contact portions 59, 60 against the force of insertion of a plug. To avoid arc-over .~ from the most proximate part of energized contact/terminals 22, ramps 83A and 83B extend upward from the top of the middle pier 82. In addition, wall members 84 and 85 extend upwardly-from the base of body 12 to help locate the ground member 34 and to prevent arc-over from the ad~acent contacts .~ 22. Also, as is evident from FIGURE 4, the receptacle body 3~ and/or cover may be formed with very slight notches (not .
. - : , .. .
. : , . . ; , . . ~
numbered) for accommodating grounding element 34 where it - e~tends through the device housing when fully assembled.
` Referring now more particularly to FIGURES 5 and 7, - there is shown a preferred embodiment of the internal ~surface of cover member 14 according to the present invention ~FIGURE 5), and the pre-loading of grounding element 34 to cover member 14 prior to final assembly of the device (FIGURE 7). As preferably embodied, cover member 14 ~ is provided with a pair of L-shaped studs 101 and 102 which 1~ are adapted to partially surround, and provide a friction 11 ~it with flanges 77 and 78 on grounding member 34 to secure i~ grounding element 34 to the cover for the assembly i, ~paration~ The distance between the opposed short legs of l~ studs 101 and 102 is slightly less than the distance between ~, the free end edges of fingers 77 and 78~ Thus, as grounding 1~ al~ent 34 is pre-loaded onto cover member 14, fingers 77 " and 78 tend to be bent upwardly by engagement with the studs i~ 101 and 102 to become wedged against the studs and secure l- member 34 in place. In addition, the long legs of studs 101 ~nd 102 are received in slots 77A and 77B to help align the ~ -~ grounding element properly relative to the cover member -~ during the pre-loading step~
.~, As preferably embodied,the back of mounting strap portion 15 is provlded with slightly indented area 109 around aperture 15B for receiving head portion 50~
Additional structures may be formed on cover member 14 to assure proper alignemnt of parts. For example, pins 103 and 10-. may be formed on cover member 14 to provide a slot-li~;e . recess for proper alignment of studs 27 and 28 on ground ,~ member 26 with canted fingers 74 and 75 on grounding ele~ent 3~ to assure good electrical mating of these elements. Forthe same reason, block-like pin 105 may be formed on cover 1~'. to support connecting portion 54 and thereby brace the cante~ fingers 7~ and 75 when engaged by studs 27 and 28 of ~r^.und member 26.
Assembly of the receptacle device according to the inv.ention, is relati~ely simple to carry out. The ra.cepta.-le body is placed on its bottom wall and the ~ electrical contacts/terminals 22 are simply seated in their 1~ appropriate slots in body 12 and ground terminal 26 is 11 inserted into position to complete corner 12C of the body.
~ 17ha grounding member 34 is press fit against cover by 13wadgin~ ~langes 77, 78 against L~shaped studs 101, 102 and 1~by bending prcngs 55A and 56A over the rim of aperture 15A
1~. to. pre-load member ;4 onto cover 14, as described above.
,2, ~a covar, with grounding member 34 attached thereto, is placed ovar body member 12, and the cover and body ara ~orced against each other and subjected to sonic welding, 1~ thareby causing the cover and body to become joined toc,ether ?~ and orm a welded seam along their abutting side and end ~i wall edges. (Meanwhile, studs 27 and 28 of ground member 26 are pushed up against the canted fingers 71 and 72 to form ,~ good electrical mating between the two grounding parts.) It will be understood that by using sonic welding techniques, the strength of the bond between the body and cover is at least as strong as the actual wall segments which are welded to~ether, thereby obviating any of the potential dangers of l.oosening o~ electrical connections within the device which ,~ other~.ise can result from a wea~ened rivet or screw--type ~astener.
:,;.
. ~
It will be readily appreciated that the invention in its broader aspects is not limited to the specific embodiment herein shown and described. Rather, variations may be made therefrom within the scope of the accompanying clai~s without departing from the principles of the invention and without sacrificing its chief advantages.
~`
' --~., ;
i~
~
~'~
_ , .
, . :
, ~ ~ .
- 2~ -
1~ terminal assembly comprises a unitary structure which 11 incl~des two pairs of contact members (24, 25) adapted to 1~ ~rasp the blades of a plug and a pair of terminal portions ~each indicated at 23) which are connected together by a 14 bridging portion (each indicated at 23A). The terminal - l~ members include threaded holes for receiving termination 1~ screws (each indicated at 30) which are thus accessible from 1~, the exterior of the body.
l~ As here embodied, body 12 is made up of a bottom 1~ wall with a pair of oppositely disposed sidewalls and a palr o~ oppositely disposed endwalls upstanding from the bottom ~all~ The body includes several upstanding interior walls ~2 to define, e.g., the slots or co~partments for receiving the electrical contact/terminal assemblies 22 as well as several guidance pins (e.g., indicated at 17) to heIp align the ~ cover and body during the final assembly step~ However, ~ since many of these internal body structures are of 2~ generally conventional configuratlon, they need not be ~ described in great deta~ niy tnose structures which will ,~ facilitate an understanding of the various features of the 3~ present invention will be mentioned in detail hereinafter.
Referring particularly to FIGURES 4, 5 and 7, the preferred integral formation of cover member 14 and mounting strap elements 15 and 16 will be more apparent. As-indicated above, in accordance with the invention and in `~ order to reduce the number of parts and manufacturing costs, 6 the l-eceptacle mounting strap is molded integrally with ~ ~over member 14 in the form of mounting strap elements 15, 1~ e~tending from opposite ends of the device cover. Each ~ mo~nting strap elèment includes an aperture (lSA, 16A) 1~ proportioned to receive the device mounting screw. As will 11 be described kelow, at least one of the apertures is adapted J ' ~0 achieve automatic grounding of the receptacle to a 3 ~rounded electrical outlet box in accordance with the ~ invention.
- '~ Advantageously and as preferably embodied, the 1~ ~nounting strap elements are formed such that the overall langth o~ the device, as measured from their extreme opposite ends, is increased relative to the overall length o~ conventional steel mounting straps. Preferably, the ,~ mounting strap elements extend to the maximum possible length that can be accommodated under the wallplate to be used with the device. According to the invention, in order to facilitate maximum elongation of mountlng strap portions 15 and 16, they are each advantageously provided with continuous beveled front end edges, 15B and 16B, respec-ti~ely, to fit under the end edges, or rim, of the wallplate (shown in phantom in FIGURE 3). For example, for standard si~e wallplates, the overall length of strap elements 15 and 1~ may be appro~:imately o.l to 0.125 inches longer than conventional steel straps, for a total overall length of about ~ 3/16 to about 4 1/4 inches.
3 It will be understood by those skilled in the art - that the integral mounting strap portions of the present ~ invention can be elongated even further for installations in o which larger wallplates are to be used. For example, the 7 strap can be approximately 3/8 inch longer (l.e., about 4 $ 9~16 to 4 5~8 inches) for use with wallplates sold under the g "SE~II JU~BO" designation by Slater Electric Inc., Glen Cove, 1~ New York. Figure 2 illustrates an embodiment of such 11 further elongation as further mounting strap elements 15c `L ~ and 16c which project from the end edges of mounting strap 1~ elements 15 and 16, respectively. Further strap elements 4 15c and 16c are preferably beveled at their end edges (as ~ indicated at 15d and 16d, respectively) to fit under a l~ wallplate substantially as described above in connection with beveled edges 15b and 16b. In addition, further ~ elemants 15c and 16c can be defined by notches 15e and 16e, 1~ respectively (similar to notchès 37 and 38 which are ?~ descried below), to form them as break-off tabs like tab 35 ~ and 36 descibed below.
22 It will be appreciated by those skilled in the art 3 that by maximizing the length of the strap elements, the ~4 maximum surface area is provided for ensuring that the strap .~ will abut some surface of a wall member when mounted to an outlet box. This arrangement will greatly reduce the possibility of a "floating" installation.
Also advantageously, strap elements 15 and 16 ~ extend at least as wide as (and preferably wider than) the 3~ width of the cover portion and they preferably include ~36~1~
-' s~uared-off side portions instead of the typical round - "ears" found on conventional steel mounting straps. The widened and squared-off side portions of the mounting strap elements are advantageous in that they further increase the -S total surface area available to abut some portion of the 6 w~ll member ln which the mounting hole is formed.
For use with special configuration outlet boxes whera the elongated mounting strap may be longer than '? desirad for the particular installation (e.g. for so-called "old ~ork" boxes or mobile home boxes), strap elements 15 1~ and 16 include break-off sections 35 and 36 (FIGURE 2) which n be snapped off along diagonally extending notches 37 and 13 38 and recessed portion 39, thus reducing the overall length f the mounting strap.
13 Referring now to FIGURES 4 and 8-11, there are shown the component parts of a pre~erred embodiment of the improved grounding system according to the invention. As here embodied, a relatively elongate grounding element (34) is provided in the ~orm of a bus bar type conductor which is located within the receptacle housing. Grounding element 34 ~i is a unitary member which may be stamped in side-by-side 2~ arrangement from a relatively thin, continuous metal strip made of copper alloy, to provide automatic grounding in a single unitary part. As here embodied, element 34 includes mounting head portion 50, stem portion 76, broadened stem portion 79, and a pair of ground contact portions 59 and 60 all formed in a unitary part. Head portion 50 is provided ith a ~enerally H-shaped aperture (indicated g-ener~ at ~?~ ~) to ~orm a pair of spring-like fingers ~55, 56) which are 3~- adapted to grasp a device mounting screw to provide the - automatic grounding according to the invention, as will be - d~scribed in greater detail hereinafter.
The resultant H-sha~ed aperture is thus surrounded by top edge 51, side edges 52 and 53 and connecting segment 5~l, leaving the cantilever-like fingers 55 and 56 extending towards each other from top edge 51 and connecting segment ~, respectively. As is evident from FIGURE 9, connecting se~ment 54 has a double bend, or a somewhat S-shape, for ~ l~cating contact head 50 in proper position adjacent the l~ mounting screw hole 15A. In addition, the H-shaped aperture 11 ~8 preferably extends through at least the uppermost bend of l_ connecting segment 54 and down to the second bend to provide 1~ increasad flexibility and spring action for fingers 55 and i~ 56~ Connecting segment 54 will thus consist of a solid 1~ sub-segment 54a with three separate upstanding connecting 16 sub-segments 54b, 54c and 54d. Sub-segments 54b and 54c ~, c~nnect side edges 52 and 53, respectively, to sub-segment ~,~ 54a, while sub-segment 54d connects finger 56 to sub-segment 1~ 5~a. As preferably embodied, the width of sub-segment 54d equals the total of the widths of sub-segments 54b and 54c.
~i It will thus be understood that, as a result, each finger 55 and 56 will be equally spring biased so that as a mounting screw is inserted between the fingers, the screw will be subjected to equal, but oppositely directed, spring forces by fingers 55 and 56.
Also advantageously, the ends of both fingers 55 and 56 are bent forward by about 90 to form a pair of prongs (55A and 5GA, respectively) which project outwardly ~ from head portion 50. The prongs are positioned to project 3~ through aperture 15A when the grounding element is located 12~6~
in place, and, advantageously, the distance between the two prongs should be at least slightly less than the diameter of the device mcunting screw so that it will be firmly grasped by the prongs and provide good electrical contact there-between. Also, as preferably embodied, the prongs 55A and ~6A are, themselves, bent back towards the rim of aperture ~ 15A to help secure, or pre-load, the grounding element onto the cover member 14, as indicated in phantom in FIGU~E 9.
~ According to the invention, electrical connection 1~ between ~he grounding prong of a typical 3-conductor 11 grounded plug (not shown) and receptacle 10 is established i~ through integrally formed ground contact portions 59 and 3 60. As here embodied, ground contact portions 59 and 60 are s~bstantially identical in that they are formed as a result ~- of a generally I-shaped aperture stamped into the grounding 1~ element 34, resulting in a pair of flanges (71, 72) which depend from the remaining side edges (63, 64, respectively) ~ ~ the grounding element, and are bent angularly inwardly so 1~ as to project downwardly toward each other, and into the ~,~ interior of body 12 when installed in the device, as will be ~vide.nt from the description below. The bent fingers thus ~2 provide an inwardly taperlng opening (indicated at 73) for receiving and contacting the grounding prong of an electrical plug when the plug is inserted into the assembled receptacle. The side edges 63, 64 may also be bent so as to ~e generally co-planar with flanges 71 and 72, thereby ~, providing an enlarged funnel-like opening for the ground prong.
Grounding element 34 is also advantageously provided with a pair of fingers (77, 78) which project ~2~36~
laterally outward from the grounding element for locating - element 34 in its desired position for the final assembly 3 operation. As here embodied, fingers 77, 78 are formed by notches 77A and 78A cut into broadened stem portion 79. The ~ ~in~ers are proportioned to be wedged against projections t) 101 and 102 ~described below) formed on the cover member 14 t~ help secure the grounding element 34 to the cover member along with the oppositely bent segments on prongs 55A and ~ 5~A, which secure terminal head portion 50 to the rim of 1~ aperture 15A. In this way, the grounding element is 11 pre-loaded to the cover member prior to assembly and will be l_ seated in proper position when the cover is placed over the 13 ra~aptacle body to facilitate automated assembly of the 1~ r~ceptacle device.
1~ Broadened stem portion 79 is also advantageously 1~ p~ovided with an aperture 80 proportioned to threadably 11 raceive a wall plate mounting screw in order to ground the ~ wallplate screw. The diameter of aperture 80 is preferably 1~ about equal to the interior thread diameter of the wall plate screw, and it includes a series of notches 80A (here, there are four such notches) formed symmetrically around ~2 aperture 80 to provide deformable thread-engaging fingers ~ (not numbered~. In use, as the wallplate mounting screw is threaded into aperture 80, these thread-engaging fingers will be deformed to conform to the helical pattern of the sc~ew threads and provide reliable grounding of the wall plate mounting screw to the device.
To facilitate threaded engagement between the wall ~ plate screw and aperture 80, body 12 is provided with hollow 3~ annular pillar 90 which is aligned with aperture 80 when the ~36~
device is fully assembled. The upper edge of pillar 90 supports ground element 34 in the vicinity surrounding aperture 80 during insertion of the wall plate screw. In ~ addition, the hollow pillar is preferably proportioned to S threadably receive the shank of the wallplate mounting screw hich is initially inserted through hole 41 in cover 14) , not only to protect it from inadvertent contact with or arc-over from the energized contact/terminals 22 but also to ~ hold the wallplate in place.
1~ Groundinq element 34 may also be formed to 11 auto~ati-cally ground the wallplate mounting screw when used 1' in a decorator style receptacle device. As shown in phantom ~, in FIGURE 8, head portion 50 may be formed with extended 1~ head portion 50A which includes a U-shaped slot 58A. When 1~ the decorator style device is assembled, slot 58A is 1~ positioned behind one of the wallplate mounting screw `
1, openings (similar to opening 41 formed on receptacle cover 1~ 14) ~ormed at either end of the the decorator receptacle 1~ ~a~a~ The width of slot 58A is preferably slightly less thall the outer thread diameter of the mounting screw. Thus, ~ i in view o~ the foregoing descriptions, it will be understood ? ~ that as the screw is threaded in slot 58A, it will thread-_ _ ~3 ably engage opposite sides of the slot, thereby causing them _~ to be distorted by the helical screw threads and assure goodelectrical contact between extended head portion 50A and the decorator-style wallplate mounting screw.
In use, the fully assembled receptacle 10 ~assembly ~ of the device in accordance with the invention will be ,~ described below) is mounted to an electrical outlet box ~ .
~ tJenerally in the usual way by inserting the device mounting ~ 19 -1~6~
scre~s (one is indicated at 7 ln FIGURE 4) through apertures l~ and 16A formed in mounting strap elements 15 and 16, 3 respectively. The screw inserted through aperture 15A is securely grasped between the pair of ~lared prongs 55A and 56A of groundinc3 element 34, forcing the prongs to flex outwardly towards the upper and lower edges of aperture 15A
hich can act as a limit for the outward flexure of the prongs). As a result, good electrical contact is maintained ~ between the mounting screw and the prongs 55A and 56A, and, therefol-e, with the entire grounding element 34.
ll In accordance with a principal advantage of the l~ invention, when the receptacle is mounted to a metallic alectrical outlet box that is already grounded, the 4 receptacle device itself will automatically be qrounded by ~ 1~ virtue of the continuous electrically conductive path 1~ a~tablished from the outlet box through the mounting screw, 1- through prongs 55A and 56A to grounding element 34 and i~ thence to the two ground con~act elements 59, 60. Thus, hen the ground prong of a plug is inserted through an aperture 21 in an outlet face member 18, the prong is ~i enc3ac3ed by, and forms electrical contact with, one of the pairs of spring-action flanges (71, 72) of the ground element, thereby grounding the electrical connection between the receptacle and the plug. To support ground contact ~ elements 59, 60 during inward insertion of the plug, body 12 ~ includes a hollow pier (each indicated at 82) located under each ground contacts 59, 60. It will also be understood ~ a~ piers ~ re~ei~e t-.e ground prong of the plug to ,J~ prevent inadvertent contact with, or arc-over from, any 31 enerc3ized contact/terminals 22 in the device.
.:
.: : .
~6~
~ As preferably embodied, device 10 is also provided - with means for grounding the receptacle by direct termina--~ tion to the ground conductor of an electrical power cable for installations wherein the outlet box is not grounded.
-S As here embodied, a portion of the end wall and the side wall at one corner of the receptacle body 12 is eliminated ~as indicated at 12c), except for a short lip 12d adjacent the bottom of body 12, and replaced by an L-shaped ground (~ 'cerminal 26 which also includes ground termination screw 32 1~ tllreadably engaged with terminal 26 for direct termination 11 to a ground conductor when needed. L-shaped ground terminal i ~ ~6 is advantageously retained in place inside lip 12d, both p ior to and during the assembly operation by a slot ndicated at 12e) formed along the body sidewall and a similal slot 12f formed between the body end wall and the adjacent hollow pier 82. Terminal 26 may also be maintained ~, in proper alignment by a tab 12g formed on the end wall which is adapted to engage notch 26A formed in terminal 26.
dvantageously and as preferably embodied, the body end ~,~ wall may extend substantially completely to the corner, as ~i indicated in phantom in FIGURE 4, for added wall strength ~-~ and to maximize the amount of material available for the preferred sonic welding assembly described hereinafter.) Terminal 26 preferably includes a pair of ground engaging studs (27, 28) which are positioned to correspond ~, in position with a pair of cante~ fingers (74, 75) formed on ground element 34 to provide electrical connection between ~, those two elements. Fingers 74 and 75 are canted (or formed ~_ at an angle) so as to flex when engaged by the studs 27 and 2~ on terminal 26, yet remain biased somewhat ayainst them, when installed in place to ensure good electrical mating between studs 27, 28 and fingers 74, 75.
-~ Thus, in the event the outlet box has not been grounded so as to take advantage of the automatic grounding provided by the present inve.ntion, the receptacle can still ba grounded by terminating the ground (green) conductor of an electrical power cable to the ground terminal screw 32 in substantially the same way as has been done heretofore. It ~ will be understood that by virtue of the good electrical 1~ contact provided between studs 27, 28 on ground terminal 26 11 and the canted fingers 74, 75 formed on ground element 34, i~ an alternate continuous ground path is provided via terminal 1~ screw 32, through ground terminal 26 and grounding element 1~ 34- Thus, when the ground conductor is terminated to screw 1~ 32, the receptacle outlets are grounded through the same 1~ qrounding element 34 that provides the automatic grounding l/ capability.
i~ Referring now to FIGURE 6, the interior configura-1~ tion of body 12 is shown, with the internal terminal/contact ~a mambers ~2 installed therein. As previously indicated, a 'i pair of raised hollow piers 82 extend upwardly from the bottom of body 12 to support ground contact portions 59, 60 against the force of insertion of a plug. To avoid arc-over .~ from the most proximate part of energized contact/terminals 22, ramps 83A and 83B extend upward from the top of the middle pier 82. In addition, wall members 84 and 85 extend upwardly-from the base of body 12 to help locate the ground member 34 and to prevent arc-over from the ad~acent contacts .~ 22. Also, as is evident from FIGURE 4, the receptacle body 3~ and/or cover may be formed with very slight notches (not .
. - : , .. .
. : , . . ; , . . ~
numbered) for accommodating grounding element 34 where it - e~tends through the device housing when fully assembled.
` Referring now more particularly to FIGURES 5 and 7, - there is shown a preferred embodiment of the internal ~surface of cover member 14 according to the present invention ~FIGURE 5), and the pre-loading of grounding element 34 to cover member 14 prior to final assembly of the device (FIGURE 7). As preferably embodied, cover member 14 ~ is provided with a pair of L-shaped studs 101 and 102 which 1~ are adapted to partially surround, and provide a friction 11 ~it with flanges 77 and 78 on grounding member 34 to secure i~ grounding element 34 to the cover for the assembly i, ~paration~ The distance between the opposed short legs of l~ studs 101 and 102 is slightly less than the distance between ~, the free end edges of fingers 77 and 78~ Thus, as grounding 1~ al~ent 34 is pre-loaded onto cover member 14, fingers 77 " and 78 tend to be bent upwardly by engagement with the studs i~ 101 and 102 to become wedged against the studs and secure l- member 34 in place. In addition, the long legs of studs 101 ~nd 102 are received in slots 77A and 77B to help align the ~ -~ grounding element properly relative to the cover member -~ during the pre-loading step~
.~, As preferably embodied,the back of mounting strap portion 15 is provlded with slightly indented area 109 around aperture 15B for receiving head portion 50~
Additional structures may be formed on cover member 14 to assure proper alignemnt of parts. For example, pins 103 and 10-. may be formed on cover member 14 to provide a slot-li~;e . recess for proper alignment of studs 27 and 28 on ground ,~ member 26 with canted fingers 74 and 75 on grounding ele~ent 3~ to assure good electrical mating of these elements. Forthe same reason, block-like pin 105 may be formed on cover 1~'. to support connecting portion 54 and thereby brace the cante~ fingers 7~ and 75 when engaged by studs 27 and 28 of ~r^.und member 26.
Assembly of the receptacle device according to the inv.ention, is relati~ely simple to carry out. The ra.cepta.-le body is placed on its bottom wall and the ~ electrical contacts/terminals 22 are simply seated in their 1~ appropriate slots in body 12 and ground terminal 26 is 11 inserted into position to complete corner 12C of the body.
~ 17ha grounding member 34 is press fit against cover by 13wadgin~ ~langes 77, 78 against L~shaped studs 101, 102 and 1~by bending prcngs 55A and 56A over the rim of aperture 15A
1~. to. pre-load member ;4 onto cover 14, as described above.
,2, ~a covar, with grounding member 34 attached thereto, is placed ovar body member 12, and the cover and body ara ~orced against each other and subjected to sonic welding, 1~ thareby causing the cover and body to become joined toc,ether ?~ and orm a welded seam along their abutting side and end ~i wall edges. (Meanwhile, studs 27 and 28 of ground member 26 are pushed up against the canted fingers 71 and 72 to form ,~ good electrical mating between the two grounding parts.) It will be understood that by using sonic welding techniques, the strength of the bond between the body and cover is at least as strong as the actual wall segments which are welded to~ether, thereby obviating any of the potential dangers of l.oosening o~ electrical connections within the device which ,~ other~.ise can result from a wea~ened rivet or screw--type ~astener.
:,;.
. ~
It will be readily appreciated that the invention in its broader aspects is not limited to the specific embodiment herein shown and described. Rather, variations may be made therefrom within the scope of the accompanying clai~s without departing from the principles of the invention and without sacrificing its chief advantages.
~`
' --~., ;
i~
~
~'~
_ , .
, . :
, ~ ~ .
- 2~ -
Claims (38)
1. An electrical outlet receptacle device adapted to be mounted adjacent a wall member having a hole therein which permits the device to be secured to an electrical outlet box mounted behind the wall member, the electrical outlet receptacle device comprising:
a receptacle body member adapted to receive and retain electrical terminal/contact assemblies which are adapted to be terminated to the conductors of an electrical power cable and to electrically mate with the blades of an electrical connecting plug;
a cover member adapted to be affixed to said body member, said cover member having apertures formed therein for permitting insertion of the plug blades for mating with said terminal/contact assemblies and said cover member having a pair of mounting strap elements formed integrally therewith and projecting from opposite ends of said cover member, said mounting strap elements terminating in free end edges which are elongated to the maximum possible length to fit under a wallplate intended for use with the device, such that when said receptacle is mounted adjacent the wall opening, the probability that the mounting strap elements will abut the wall member is maximized so as to substan-tially reduce the chance of having a "floating" installation.
a receptacle body member adapted to receive and retain electrical terminal/contact assemblies which are adapted to be terminated to the conductors of an electrical power cable and to electrically mate with the blades of an electrical connecting plug;
a cover member adapted to be affixed to said body member, said cover member having apertures formed therein for permitting insertion of the plug blades for mating with said terminal/contact assemblies and said cover member having a pair of mounting strap elements formed integrally therewith and projecting from opposite ends of said cover member, said mounting strap elements terminating in free end edges which are elongated to the maximum possible length to fit under a wallplate intended for use with the device, such that when said receptacle is mounted adjacent the wall opening, the probability that the mounting strap elements will abut the wall member is maximized so as to substan-tially reduce the chance of having a "floating" installation.
2. A receptacle device according to Claim 1 wherein the free end edges of said mounting strap elements are beveled along their front facing surfaces to permit maximum elongation of the mounting strap elements to fit under a wallplate.
3. A receptacle device according to Claim 1 wherein each said mounting strap element is generally squared along its side edges for maximizing the available surface area for abutting the wall member, thereby further reducing the chance of a "floating" installation.
4. A receptacle device according to Claim 3 wherein each said mounting strap element includes at least one diagonally extending notch formed therein to provide break off tabs which can be removed from said mounting strap elements to reduce the overall length of the mounting strap when the device is to be used with special configuration outlet boxes.
5. A receptacle device according to Claim 1, which further includes grounding means providing two pairs of electrical grounding contacts one each adjacent each ground aperture formed in the receptacle cover member for receiving a ground prong of an electrical connecting plug, said grounding means providing electrical communication between each pair of electrical grounding contacts and a mounting screw aperture formed on one of the mounting strap elements, said grounding means being proportioned to receive and grasp a mounting screw inserted through said one mounting screw aperture to provide good electrical communi-cation therebetween, such that when said receptacle device is mounted to a pre-grounded electrical outlet box, a continuous electrically conductive ground path is provided from the grounded outlet box, through the mounting screw, thence through the grounding means to each said pair of ground contacts for automatically grounding the ground prong of an electrical plug when inserted into the device.
6. An electrical outlet receptacle device according to Claim 5, wherein said grounding means comprises a unitary grounding element in the form of a somewhat elongate strip of copper alloy, said grounding element having each pair of ground contact members formed integrally therewith and positionable adjacent each ground prong opening of the receptacle cover member and a pair of spring-like finger members at one end, said finger members positioned and proportioned to extend through the mounting screw aperture formed on said one mounting strap element for engaging said mounting screw.
7. An electrical outlet receptacle device according to Claim 6 which further includes an additional ground member within said receptacle device in electrical contact with said grounding element, said additional ground member including a ground terminal screw accessible from the exterior of the receptacle housing for permitting direct termination of a ground conductor in an electrical power cable to the receptacle device to provide an alternate means for grounding the device when automatic grounding of said device is not carried out through the device mounting screw.
8. An electrical outlet receptacle device according to Claim 1 wherein said body and cover members are formed from an injection moldable thermo-plastic material.
9. An electrical outlet receptacle device according to Claim 5 wherein said body and cover members are made from an injection moldable thermo-plastic material.
10. An electrical outlet receptacle device according to Claim 8, wherein said body and cover members are secured together by sonic welding techniques.
11. An electrical outlet receptacle according to Claim 9, wherein said body and cover members are secured together by sonic welding techniques.
12. An electrical outlet receptacle device according to Claim 7, wherein said grounding element includes an aperture formed therein for receiving a wallplate mounting screw for automatically grounding said wallplate mounting screw when threaded through said aperture.
13. An electrical outlet receptacle device accord-ing to Claim 12, wherein said aperture includes at least one relatively deformable thread engaging finger adapted to be received within the helical threads within the wallplate mounting screw, each said finger being deformed to conform to the helical pattern of the screw threads when said wallplate mounting screw is threaded into said aperture in order to provide reliable electrical mounting between said grounding element and said wallplate mounting screw.
14. An electrical outlet receptacle device according to Claim 7, wherein said head portion of said grounding element includes a generally H-shaped opening formed therein to provide said pair of spring fingers which project toward each other to protrude into the mounting screw aperture of said one mounting strap element, said spring fingers being bent outwardly so as to protrude substantially through the mounting screw aperture.
15. An electrical outlet receptacle device accord-ing to claim 14 wherein said spring fingers are spring biased so as to move away from each other with a generally equal but oppositely directed spring biasing force.
16. An electrical outlet receptacle device accord-ing to Claim 15 wherein said ground element includes a pair of relatively deformable finger members projecting in generally opposite directions from each other, and wherein said cover member includes a pair of projecting stud members which are spaced apart by a distance slightly less than the distance between the free end edges of said deformable finger members such that said grounding element can be pre-loaded onto said cover member by pushing said grounding member against said cover member and forcing said deformable finger members between said projecting studs to cause said finger members to deform slightly and become wedged against said stud members, thereby securing said grounding element to said cover member.
17. An electrical outlet receptacle device according to Claim 16, wherein said grounding element includes a pair of slots and wherein said cover member includes stud means proportioned to fit within said slots for aligning said grounding element on said cover member while it is being pre-loaded onto said cover member.
18. An electrical outlet receptacle device according to Claim 17 wherein said deformable finger members and said slots are formed adjacent each other on said grounding element and wherein said projecting studs are formed adjacent each other to form a pair of generally L-shaped stud assemblies, each L-shaped stud assembly having one leg adapted to fit within one of said slots and its other leg being adapted to be wedged against the free end of one of said deformable finger member.
19. An electrical outlet receptacle device according to Claim 18 wherein said prongs of said mounting screw engaging fingers are bent away from each other around the rim of said one aperture to help attach said grounding element to said cover member.
20. An electrical outlet receptacle device according to Claim 7 wherein said additional ground member includes at least one integral stud projecting from one edge of said additional ground member, each said projecting stud being positioned to make electrical mating contact with a deformable finger formed on said grounding element, such that good electrical mating contact is provided between said grounding element and said additional grounding member without the need for welding or other permanent attachment between said grounding element and said additional ground member.
21. An electrical outlet receptacle device accord-ing to Claim 7, wherein said grounding element includes a further head portion projecting from said head portion, said further head portion having a generally U-shaped slot proportioned to threadably receive a mounting screw for a decorator style wallplate member.
22. An electrical outlet receptacle device adapted to be mounted to an electrical outlet box through an opening in a wall member, the electrical outlet receptacle device comprising:
a receptacle body member adapted to receive and retain electrical terminal/contact assemblies to be terminated to the conductors of an electrical power cable and to electrically mate with the blades of an electrical connecting plug;
a cover member attached to said body member to form a substantially enclosed receptacle housing, said cover member including apertures formed therein to permit insertion of the plug blades for mating with said terminal/
contact assemblies, said receptacle housing including mounting strap elements extending from each end thereof for mounting the receptacle to an outlet box; and, grounding means within said receptacle housing, said grounding means providing two pairs of electrical grounding contacts adjacent each ground aperture formed in the receptacle cover member for receiving a ground prong of a plug and said grounding means providing electrical communication between each said pair of electrical grounding contacts and a mounting screw aperture formed on one of the mounting strap elements, said grounding means being propor-tioned to receive and grasp a mounting screw inserted through the mounting screw aperture in said one mounting strap element to provide electrical contact therebetween, such that when said receptacle device is mounted to a pre-grounded electrical outlet box, a continuous electri-cally conductive ground path is provided from the grounded outlet box, through the mounting screw, thence through the grounding means to each said pair of electrical grounding contacts for automatically grounding the ground prong of an electrical plug inserted into the receptacle device.
a receptacle body member adapted to receive and retain electrical terminal/contact assemblies to be terminated to the conductors of an electrical power cable and to electrically mate with the blades of an electrical connecting plug;
a cover member attached to said body member to form a substantially enclosed receptacle housing, said cover member including apertures formed therein to permit insertion of the plug blades for mating with said terminal/
contact assemblies, said receptacle housing including mounting strap elements extending from each end thereof for mounting the receptacle to an outlet box; and, grounding means within said receptacle housing, said grounding means providing two pairs of electrical grounding contacts adjacent each ground aperture formed in the receptacle cover member for receiving a ground prong of a plug and said grounding means providing electrical communication between each said pair of electrical grounding contacts and a mounting screw aperture formed on one of the mounting strap elements, said grounding means being propor-tioned to receive and grasp a mounting screw inserted through the mounting screw aperture in said one mounting strap element to provide electrical contact therebetween, such that when said receptacle device is mounted to a pre-grounded electrical outlet box, a continuous electri-cally conductive ground path is provided from the grounded outlet box, through the mounting screw, thence through the grounding means to each said pair of electrical grounding contacts for automatically grounding the ground prong of an electrical plug inserted into the receptacle device.
23. An electrical outlet receptacle device according to Claim 22, wherein said grounding means comprises a unitary grounding element in the form of a somewhat elongate strip of copper alloy, said grounding element having each pair of ground contact members formed integrally therewith and positionable adjacent each ground prong opening of the receptacle cover member and a pair of spring-like finger members at one end, said finger members positioned and proportioned to extend through the mounting screw aperture formed on said one mounting strap element for engaging said mounting screw.
24. An electrical outlet receptacle device according to Claim 23 which further includes an additional ground member within said receptacle device in electrical contact with said grounding element, said additional ground member including a ground terminal screw accessible from the exterior of the receptacle housing for permitting direct termination of a ground conductor of an electrical power cable to the receptacle device to provide an alternate means for grounding the device when automatic grounding of said device is not carried out through the device mounting screw.
25. An electrical outlet receptacle device accord-ing to Claim 24, wherein said grounding element includes an aperture formed therein for receiving a wallplate mounting screw for automatically grounding said wallplate mounting screw when threaded through said aperture.
26. An electrical outlet receptacle device accord-ing to Claim 25, wherein said aperture includes at least one relatively deformable thread engaging finger adapted to be received within the helical threads within the wallplate mounting screw, each said finger being deformed to conform to the helical pattern of the screw threads when said wallplate mounting screw is threaded into said aperture in order to provide reliable electrical mounting between said grounding element and said wallplate mounting screw.
27. An electrical outlet receptacle device according to Claim 24, wherein said head portion of said grounding element includes a generally H-shaped opening formed therein to provide said pair of spring fingers which project toward each other to protrude into the mounting screw aperture of said one mounting strap element, said spring fingers being bent outwardly so as to protrude substantially through the mounting screw aperture.
28. An electrical outlet receptacle device accord-ing to Claim 27 wherein said spring fingers are spring biased so as to move away from each other with a generally equal but oppositely directed spring biasing force.
29. An electrical outlet receptacle device accord-ing to Claim 28 wherein said ground element includes a pair relatively deformable finger members projecting in generally opposite directions from each other, and wherein said cover member includes a pair of projecting stud members which are spaced apart by a distance slightly less than the distance between the free end edges of said deformable finger members such that said grounding element can be pre-loaded onto said cover member by pushing said grounding member against said cover member and forcing said deformable finger members between said projecting studs to cause said finger members to deform slightly and become wedged against said stud members, thereby securing said grounding element to said cover member.
30. An electrical outlet receptacle device accord-ing to Claim 29, wherein said grounding element includes a pair of slots and wherein said cover member includes stud means proportioned to fit within said slots for aligning said grounding element on said cover member while it is being pre-loaded onto said cover member.
31. An electrical outlet receptacle device accord-ing to Claim 30 wherein said deformable finger members and said slots are formed adjacent each other on said grounding element and wherein said projecting studs are formed adjacent each other to form a pair of generally L-shaped stud assemblies, each L-shaped stud assembly having one leg adapted to fit within one of said slots and its other leg being adapted to be wedged against the free end of one of said deformable finger member.
32. An electrical outlet receptacle device accord-ing to Claim 31 wherein said prongs of said mounting screw engaging fingers are bent away from each other around the rim of said one aperture to help attach said grounding element to said cover member.
33. An electrical outlet receptacle device according to Claim 24 wherein said additional ground member includes at least one integral stud projecting from one edge of said additional ground member, each said projecting stud being positioned to make electrical mating contact with a deformable finger formed on said grounding element, such that good electrical mating contact is provided between said grounding element and said additional grounding member without the need for welding or other permanent attachment between said grounding element and said additional ground member.
34. An electrical outlet receptacle device accord-ing to Claim 24, wherein said grounding element includes a further head portion projecting from said head portion, said further head portion having a generally U-shaped slot proportioned to threadably receive a mounting screw for a decorator style wallplate member.
35. A method for assembling an electrical outlet receptacle device having a cover member and a body member both made from an injection moldable thermo-plastic material And forming a device housing when assembled together, said method comprising the steps of:
inserting electrical terminal/contact assemblies into the interior of the receptacle body portion when lying on its bottom wall;
pre-loading a grounding element to the cover member along an interior surface thereof, with pairs of ground con-tacts positioned adjacent each ground prong opening formed in the cover member for receiving the ground prong of an electrical connecting plug and with a pair of screw engaging fingers protruding through a mounting screw aperture formed in one of the mounting strap elements on the receptacle device;
placing the cover member with the grounding element pre-loaded thereto over the open top of the receptacle body portion;
forcing said cover member and body member against each other to secure the contact members in place; and sonically welding the two members together to form a securely assembled receptacle housing.
inserting electrical terminal/contact assemblies into the interior of the receptacle body portion when lying on its bottom wall;
pre-loading a grounding element to the cover member along an interior surface thereof, with pairs of ground con-tacts positioned adjacent each ground prong opening formed in the cover member for receiving the ground prong of an electrical connecting plug and with a pair of screw engaging fingers protruding through a mounting screw aperture formed in one of the mounting strap elements on the receptacle device;
placing the cover member with the grounding element pre-loaded thereto over the open top of the receptacle body portion;
forcing said cover member and body member against each other to secure the contact members in place; and sonically welding the two members together to form a securely assembled receptacle housing.
36. A method according to Claim 35 wherein said step of pre-loading said grounding element to said cover member includes the step of forcing a pair of oppositely projecting deformable fingers on said grounding element between a pair of projecting studs formed on said cover member, the spacing between said studs being slightly less than the distance between the free ends of said oppositely projecting deformable finger members, such that as said grounding element is forced against said cover member, said spring fingers deform slightly so as to become wedged against said projecting stud members on said cover member.
37. A method according to Claim 36 wherein said pre-loading step further includes the step of bending said screw engaging fingers about the rim of the mounting screw aperture formed on one of said mounting strap elements to help fasten said grounding element to said cover member.
38. A method according to Claim 35, which further includes the step of providing an additional grounding member in said body member in such position that when said cover and body members are forced together during said sonic welding step, said additional grounding member and said grounding element are in electrical mating relation to provide alternate grounding means via a ground terminal screw on said additional grounding element for direct termination to a ground conductor in an electrical power cable.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/010,373 US4854885A (en) | 1987-02-03 | 1987-02-03 | Electrical outlet receptacle with non-metallic mounting strap and automatic grounding |
| US010,373 | 1987-02-03 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1286011C true CA1286011C (en) | 1991-07-09 |
Family
ID=21745459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000557925A Expired - Lifetime CA1286011C (en) | 1987-02-03 | 1988-02-02 | Electrical outlet receptacle with non-metallic mounting strap and automatic grounding |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4854885A (en) |
| CA (1) | CA1286011C (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5266039A (en) * | 1992-11-13 | 1993-11-30 | General Electric Company | Electrical outlet receptacle |
| NZ247121A (en) * | 1993-03-11 | 1996-12-20 | Pdl Holdings Ltd | Electrical outlet with earth strap in aperture for fixing screw |
| US5472350A (en) * | 1994-01-14 | 1995-12-05 | Pass & Seymour, Inc. | Electrical receptacle and terminals |
| DE19700574C1 (en) * | 1997-01-10 | 1998-06-25 | Axel Strupatis | Concealed installation device |
| US5975925A (en) * | 1997-09-29 | 1999-11-02 | Hubbell Incorporated | Grounded and isolated electrical receptacle assemblies with interchangeable components |
| US5967815A (en) | 1998-03-19 | 1999-10-19 | Marc A. Schlessinger | Variable orientation switching type electrical receptacle |
| US20020019168A1 (en) * | 1999-01-12 | 2002-02-14 | Robert W. Hooley | Pin array header with floating surface mount interconnects |
| US6206737B1 (en) | 1999-02-19 | 2001-03-27 | Hubbell Incorporated | Enhanced terminal screw with impeller wire gripping elements |
| US6774307B2 (en) | 2002-05-07 | 2004-08-10 | Applied Technology And Solutions | Through-wall electrical system |
| FR2852153B1 (en) * | 2003-03-03 | 2005-05-27 | Legrand Sa | ELECTRICAL EQUIPMENT WITH EARTH CONNECTION METAL BARRIER |
| US20060057873A1 (en) * | 2004-09-14 | 2006-03-16 | Duh-Socket, Inc. | Electrical receptacle for outward facing ground plugs |
| US7198514B1 (en) * | 2005-12-12 | 2007-04-03 | Grimes Steve M | Junction box apparatus |
| US7241170B1 (en) | 2006-04-07 | 2007-07-10 | Cisco Technology, Inc. | Permanent terminations of network cables |
| US20130130551A1 (en) * | 2011-11-22 | 2013-05-23 | ThinkEco, Inc. | Blade and Housing Assembly |
| US10014137B2 (en) | 2015-10-03 | 2018-07-03 | At&T Intellectual Property I, L.P. | Acoustical electrical switch |
| US9704489B2 (en) | 2015-11-20 | 2017-07-11 | At&T Intellectual Property I, L.P. | Portable acoustical unit for voice recognition |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3835438A (en) * | 1972-06-29 | 1974-09-10 | Paulding J Inc | Self-grounding clip for the mounting strap of an electric switch or receptacle |
| US4039235A (en) * | 1976-01-23 | 1977-08-02 | Sola Basic Industries, Inc. | Electrical receptacle |
| US4203638A (en) * | 1978-10-10 | 1980-05-20 | Eagle Electric Mfg. Co., Inc. | Electrical receptacle and grounding strip therefor |
| US4271337A (en) * | 1979-09-17 | 1981-06-02 | Harvey Hubbell Incorporated | Safety receptacle |
| US4379605A (en) * | 1980-11-17 | 1983-04-12 | Harvey Hubbell Incorporated | Electrical receptacle of molded body construction |
-
1987
- 1987-02-03 US US07/010,373 patent/US4854885A/en not_active Expired - Fee Related
-
1988
- 1988-02-02 CA CA000557925A patent/CA1286011C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US4854885A (en) | 1989-08-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1286011C (en) | Electrical outlet receptacle with non-metallic mounting strap and automatic grounding | |
| US4865556A (en) | Electrical switch device with non-metallic mounting straps and automatic grounding | |
| EP0821438B1 (en) | Terminal fitting | |
| KR100501561B1 (en) | Cowl Connector for Electrical Terminals | |
| CA1298369C (en) | Insulation displacement members and electrical connectors | |
| US6178106B1 (en) | Power distribution center with improved power supply connection | |
| US4220388A (en) | Electrical connector and contact and housing therefor | |
| US4113179A (en) | Connector constructions and attaching means therefor | |
| US4718866A (en) | Electrical connector shield case and method of making same | |
| EP0362598B1 (en) | Electrical connector | |
| US6126495A (en) | Miniaturized plug-in contact element | |
| US5445534A (en) | Double lock male/female type connector | |
| US5593313A (en) | Socket with a plug locking mechanism | |
| US4728295A (en) | Connector block for electrical devices | |
| US5980333A (en) | Connector members | |
| AU729016B2 (en) | Mount for a circuit board including a mounting bracket and receptor for the bracket | |
| US4124267A (en) | Mounting clip for a connector | |
| GB2183937A (en) | Female electrical contact member | |
| CA2249723C (en) | Multi-contact electrical terminal for electrical receptacle assembly | |
| JPS61294779A (en) | Shield type receptacle connector | |
| US4298242A (en) | Electrical socket contact | |
| EP0496276B1 (en) | Electrical conductor trap terminal and connector | |
| US4793059A (en) | Automatic grounding clip | |
| KR100326219B1 (en) | Electrical connector with terminal position assurance device | |
| US5356309A (en) | Connector block with releasable mounting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |