US 3723948 A
An electrical connector or circuit component capable of being rapidly attached to insulated wires and having a base member channeled to receive mutually electrically insulated wire conductors, e.g., insulated copper wires carried in a non-metallic sheath, such as used to carry current in machines or buildings, conductive contact elements capable of being forcefully applied to wire conductors to make electrical contact without preliminary stripping of the insulation or severing of the wire conductor, an insulating body member retaining the elements and including parts thereon characterizing the circuit component, and holding means to hold together the base and body.
Claims available in
Description (OCR text may contain errors)
[ 51 Mar. 27, 1973  ELECTRICAL COMPONENT  Inventors: Gerald A. Wyatt, Shoreview; Gail A.
Anderson, St. Paul, both of Minn.
 Assignees Minnesota Mining and Manufacturing Company, St. Paul, Minn.
 Filed: Nov. 8, 1971  Appl. No.: 196,290
Related US. Application Data  Continuation of Ser. No. 73,414, Sept. 18, 1970,
 US. Cl. ..339/99 R, 339/14 R  Int. Cl. ..1-l01r 9/08  Field of Search ..339/14, 95, 97-99, 339/164  References Cited UNITED STATES PATENTS 2,719,957 10/1955 Abbott ..339/99 R 2,802,083 8/1957 Lapeyre ..339/97 R 3,434,093 3/1969 Wedekind 3,496,522 2/1970 Ellis, Jr. et a1. ..339/99 R Primary Examiner-Joseph McGlynn Attorney-Alexander, Sell, Steldt & Delahunt 57 ABSTRACT An electrical connector or circuit component capable of being rapidly attached to insulated wires and having a base member channeled to receive mutually electrically insulated wire conductors, e.g., insulated copper wires carried in a non-metallic sheath, such as used to carry current in machines or buildings, conductive contact elements capable of being forcefully applied to wire conductors to make electrical contact without preliminary stripping of the insulation or severing of the wire conductor, an insulating body member retaining the elements and including parts thereon characterizing the circuit component, and holding means to hold together the base and body.
7 Claims, 7 Drawing Figures Patented March 27', 1973 2 Sheets-Sheet 1 NT 5 U mm m 4 MA w A0 BY M Patented March 27, 1973 2 Sheets-Sheet 2 [/v VEN TOPS GA. A, ANDERSON GERALD A. WYATT A 7' TORNEYS ELECTRICAL COMPONENT This is a continuation application of Ser. No. 73,414, filed Sept. 18, 1970, and now abandoned.
This invention relates to electrical components, and in particular to electrical components that are easily installed on mutually insulated wire conductors carried in a non-metallic sheath without preliminary stripping of the insulation, and without the necessity of severing the wire conductor. A typical use of the electrical component lies in electrical wiring, e.g., in the wiring of prefabricated homes, trailer homes, and the like.
conventionally, wire conductors are attached to electrical connectors or circuit components by screw or other kinds of pressure fasteners. These methods are time consuming and may require stripping or cutting of the wire conductor such as shown in U.S. Pat. No. 3,510,822. Electrical components are known which eliminate the necessity of stripping the insulation from the wire conductor. For example, see U.S. Pat. No. 2,873,435 which discloses an electrical device which can be attached to a wire end without stripping. This, however, is limited to use on wire conductor ends and, therefore, requires that the wire conductor be severed.
This invention is intended to provide an electrical component to which speedy, simple, lasting, low resistance connections can be made to wire conductors without requiring stripping or severing of the wire conductor. The components can be rapidly and easily installed with considerably less time and effort than that required for conventional devices for the same purpose. The electrical components of the invention are small in size as compared to the conventional devices, thus take less storage space, and also less space upon installation.
The invention contemplates making connections to wires having diameters in the A.W.G. wire size range of Number 14 through Number 10. The electrical components of the invention utilize, for making electrical connections with wire conductors wires in the aforementioned range, an arrangement similar to that disclosed in U.S. Pat. No. 3,012,219. In this arrangement one or more wire conductors are supported on a transversely slotted surface and a connector or bridge member including at least one slotted conductive plate is forced onto the wire conductors and into the slotted base. The plate pierces insulation on the wire conductors and enters into firm contact with the wire conductor. The plate is thin and resilient so that the jaws defining the slots resiliently spread apart and exert compression on the wire. Connections made in this manner have been tested and found to have a very low resistance and to maintain their high conductivity through repeated mechanical stresses, temperature or pressure changes, exposure to moisture or the passage of electric current.
The arrangements disclosed in the abovementioned patent, however, has been generally limited to making connections between wires, or to connections at terminal ends of wires. U.S. Pat. No. 3,258,733 recognizes that the arrangement can be used for the purpose of connecting together, without severing, parallel individual wires, but fails to disclose connections to parallel wires bound in a unitary bundle, e.g., a three wire power cored carried in a none-metallic sheath.
The present invention provides an electrical component with a novel base arrangement which is channeled to receive and separate three wires while maintaining substantially equal tension on each of the wires. The outermost channels are oppositely arcuate to permit each of the wires to be positively aligned with the appropriate slot in the connector plate. Surprisingly, the central wire remains substantially straight when the outer wires are separated and placed in the arcuate channels, and each wire lies substantially centered in its respective channel.
The principles of the invention will now be further described and illustrated by reference to the accompanying drawing and wherein:
FIG. l is a perspective view of an electrical component useful as an electrical outlet and showing parts thereof in exploded form;
FIGS. 2 and 3 are partial sectional views taken approximately at line 22 as indicated in FIG. 1, which illustrate a segment of the base and slotted conductive plate in elevation in two stages of application to an insulated wire;
FIG. 4 is a plan view showing the lower face of the upper or body portion of the electrical component of FIG. 1 with contact elements in place therein and wires, shown in broken lines, held in the elements;
FIG. 5 is a perspective view of another embodiment of the present invention in exploded form;
FIG. 6 is a perspective view of an electrical component useful as a lamp socket and showing a further embodiment of the invention as applied to a cable; and
FIG. 7 is a perspective view showing yet another embodiment of the present invention, i.e., a switch.
The preferred electrical component shown in FIG. 1 comprises a novel elongate insulating base 10 formed of suitable insulating material, e.g., phenolic resin, conductive contact elements 20, 21 and 22, to make electrical connection with wire conductors carried in the base, a body d0 capable of containing the contact elements and engageable with the base and a clamp 50 for holding the body and base together. The base 10 is longitudinally channeled to provide channel 12, having dimensions for receiving the sheath covered cable, which branches into three separate wire-supporting channels, 13, 14, and i5, and converges again into a single channel 34 for supporting the sheath covered cable. The outer channels, 13 and 15, are oppositely arcuate to separate the wires. Channels 13, 14, and 15 preferably have a centrally depressed floor to provide for centering of wires of various sizes carried therein. Normally, in use, inner channel 14 will carry a ground wire, which may be a bare wire, and outer channels 13 and 15 will carry insulated conductor wires. The walls and floor of each of channels 13, 141-, and 15 are transversely grooved to provide respectively a thin groove, 16, 17, and 13, perpendicular to the channel. For conventional use, i.e., in standard locations and areas, inner channel 14 will be approximately 1% inch long with channels 13 and 15 slightly longer.
Three conductive contact elements, 20, 21, and 22, one for each of the wire-receiving channels, are provided. The conductive contact elements are made of a resilient electrically conductive sheet material, e.g., spring brass, and include thin conductive plates 23, 24, and 25 projecting therefrom. The plates are of substantially the same thickness as that of the transverse grooves provided in each channel and are slidably movable and insertable within the grooves.
Each thin plate, e.g., plate 24 shown in greater detail in FIG. 2 and FIG. 3, is deeply slotted to provide slot 27 and legs 28. The narrow edges defining the slot 27 are generally parallel and include a smoothly diverging terminal portion defining a wire-accepting opening.
As shown in FIG. 2, when the thin plate 24 is positioned into its respective groove 18, the slot 27 will be in alignment with and above a wire 47 lying on the channel floor 54. As the plate 24 is forced into the groove 18, the ends of the legs 28 come into contact with the wire 47 in the channel. Upon further insertion, the wire 47 enters the narrower portion of the slot 27 and the opposing edges of the legs 28 cut into and through the insulation ayer 30 around the conductor 29. The narrow edges of the legs 28 deform the metal conductor 29 as shown in FIG. 3, and at the same time the legs are resiliently spread apart from their original position. This spreading is not sufficient to overcome the elastic strain point of the metal when the component is applied to wires. A connection results in which the legs, attempting to spring back to their original position, exert a continued pressure against the wire. The width of groove 18 must be sufficient to receive the legs when separation occurs on connection with large wires.
In the preferred embodiment the conductive plates are 0.250 inch in width measured from the outer narrow edges of the legs, and the narrow portion of the slot has an opening of 0.050 inch. For use with wires in the size range of No. l4 to No. 10, the groove must be wide enough to permit clearance of the separated legs resulting from connection with No. wire.
Conductive contact elements and 21, used to make contact with current carrying conductor wires carried in channels 13 and 15, may be cut from a flat sheet of metal to form a blank which is folded to the design as shown in FIG. 1. Conductive contact element 22, normally used to make contact with a ground wire carried in channel 14, may also be cut from such a sheet of metal to form a blank which can be folded to the desired shape, or grounding receptacles 32 or 33 may be separately cut and attached later, e.g., by riveting or welding as shown. Element 22 has openings, similar to those found in conventional electrical fixtures, provided in attaching ears 26 at opposite ends for mounting.
The conductive contact elements are shaped and constructed so as to have receptacle portions which are aligned with the holes of the duplex electrical device of the body 40. Power receptacles 35 consist of metal leafs slotted to receive the conventional contact bars of a power plug. The slots have a smoothly diverging terminal portion and an initially smaller opening at the mouth which increases approaching the base, to provide a spring action for better contact with the contact bars of a power plug. Grounding receptacles 32 and 33 are resilient, substantially U-shaped conductive elements having the legs closer at the ends than at the base, adapted to apply pressure sufficient to cause electrical contact on the grounding portion of a power plug when inserted.
Body member 40 shown in FIG. 1, formed of a suitable insulating material, is shaped to engage base 10. In the preferred embodiment base 10 fits fully within a cavity in body 40. The cavity is characterized by having substantially perpendicular walls and depth corresponding to that of the base 10. For ease of assembling of the base into body, one end of base 10 may differ in shape from the opposite end as indicated by stepped sides 48 of base 10, so that base 10 can only be put into the body in one way, thus insuring the proper alignment of the wire contact plates with their respective grooves.
Body 40, as shown in FIG. 4, is channeled to provide channels 36 and 37 which contain the conductive elements 22 and 21 respectively. The contact elements may be supported in their respective channels without fastening, or may be fastened in fixed position within body 40 by conventional means, e.g., by screws or be constructing the channels with dimensions which prevent the removal of the elements.
To install the connector to the wires of a 3 conductor cable, a small portion of the non-metallic sheath of the cable 42 is cut away, e.g., preferably less than one and one half inch, exposing the three insulated conductors 45, 46, and 47. The three insulated conductors are separated into the three wire receiving channels of the base 10. The body 40, containing the conductive elements, is aligned over the base 10 in the proper manner as hereinbefore described, and forced by hand or a suitable tool into engagement with the base while simultaneously making permanent electrical contact with all three conductors.
Body 40 and base 10 are thereafter held together by clamp 50 shown in FIG. 1. A channel 41 in body 40 and depressions 44 in the base are provided to contain the clamp. Clamp 50 may be cut from a flat sheet of metal such as from steel and folded as shown to give biasing tabs 51 having a shape capable of providing a biasing force on the base into the body, and a grounding contact element 52 which passes through hole 43 through body 40 and opening 49 in element 22, andis folded back on over the edges of the opening to prevent withdrawal therefrom and to ground clamp 50. A hole 53 in clamp 50 is provided to permit attachment of conventional electrical component wall coverplates.
FIG. 5 shows another embodiment of the present invention used for connecting one set of insulated wires to another which may be used for providing branch lines from a main electrical circuit or connecting together terminal ends of two cables. This embodiment comprises two base members 10a and 10b which fit into opposing cavities of body member 60 containing conductive contact elements 61, 62 and 63, and twin clamps 64 for holding the bases within the body. Both ends of each of the conductive contact elements are slotted as hereinbefore described in connection with FIG. 1 to pierce the insulation and make contact with wire conductors.
FIG. 6 shows yet another embodiment of the invention comprising a wire receiving and separating base member 65 assembled with a lamp, fuse, or circuit breaker socket type body member 66 containing conductive contact elements (not shown) having conventional portions thereon which contact the socket and center plug of the lamp, fuse, or circuit breaker and slotted portions which pierce the insulation and make electrical contact with the conductors of wire 67.
FIG. 7 shows still another embodiment of the invention comprising the hereinbefore described wire receiving and separating base member 73 assembled with a switch type body member 70 and containing conductive contact elements (not shown) which are connected to either terminal of a conventional switch 75 contained in body 70. A ground contact element 72 also useful for mounting is provided. The body 70 and base 73 are held together by clamp pair 74. When the switch is in the open position the contact elements are electrically isolated from one another. In closed position the contact elements are electrically connected together providing a conductive path between the wire conductors carried in the outer curved channels of the base. The opposite end of cable 71 to which the switch is connected may have one conductor connected to a current source and the other to an electrical device, in a conventional use. A separate line would then connect the circuit device to the remaining line of the current source.
It is to be understood that use of this connecting means to make electrical contact with a circuit component is not limited to the electrical components disclosed herein but is equally adapted for use with other types of connectors and circuit components such, for example, as modular lights, fuse boxes, and similar devices. The wire separating base and wire contact plates disclosed herein will be common to all the electrical components and the body will be characteristic of the desired device.
It is also to be understood that the foregoing descrip tion is illustrative only and that numerous changes can be made in the described embodiments without departing from the spirit of the invention as set forth in the claims.
What is claimed is:
1. An electrical component capable of making solderless electrical connection to insulated wire conductors of a three conductor cable covered with a nonmetallic sheath without requiring preliminary stripping of the insulation or severing of the wire conductors and having a wire-receiving base member, a body member engageable with the base and containing conductive contact elements having projecting therefrom resilient contact plate portions slotted to provide an openmouth slot adapted for forceful entry of a wire conductor, and holding means for holding the base and the body together; wherein the base member comprises: an elongate insulating block longitudinally channeled along one face to provide an enlarged channel at one end capable of receiving the sheath covered wires, said channel branching into three smaller intermediate channels capable of receiving insulated wires exposed by cutting away a short portion of said sheath, and converging again as an enlarged channel at the other end, the central intermediate channel being substantially straight and the outer intermediate channels being oppositely arcuate, said intermediate channels each having a wire-supporting floor and parallel walls, said base being transversely grooved across each of said intermediate channels with grooves of adjacent channels being nonaligned to provide grooves in said floor and walls for slidably receiving an appropriate one of said contact plate portions with the mouths of the slots of said plate portions centered in relationship to the wiresupporting floors of the intermediate channels, whereby insulated wire conductors supported in said intermediate channels are brought into permanent positive electrical connection with appropriate contact plate portions upon engagement of the body with the base.
2. The electrical component of claim 1 wherein said body member comprises an elongate insulating block having a surface engageable with the channeled face of said base, said block being slotted through said surface to an opposite surface to provide at least one pattern of holes corresponding to the projections on a 3 conductor power plug and channeled in said surface to provide channels adapted to support said contact elements, and wherein each of said contact elements is further characterized by having a slotted plug-receiving portion positioned on said contact element in its supporting channel with said plug-receiving portion in alignment with one of said holes.
3. An electrical component as defined in claim 1 further comprising a second base member as therein defined engageable with said body, said electrical component being capable of making solderless electrical connection between corresponding insulated wire conductors of non-metallic sheath-covered three-conductor cables supported in each base without preliminary stripping of the insulation or severing of the wire conductors, said body having opposite surfaces each engageable with a base, and being slotted through said surfaces to provide openings for containing the contact elements, said contact elements having two oppositely directed slotted resilient plate-like portions and being disposed in said body to slidably insert said plate-like portions into corresponding grooves of each base.
4. An electrical component as defined in claim 1 wherein said body member comprises an insulating block having a first surface engageable with the channeled face of said base, said block being slotted through said first surface to an opposite surface to provide at least one hole for receiving the base of a light bulb and channeled in said first surface to provide channels adapted to support said contact elements, and wherein the contact elements adapted to contact wires in the outer channels of the base are further characterized by having portions thereon for making electrical connection with said light bulb.
5. An electrical component as defined in claim 1 wherein said body member comprises an insulating block having a surface engageable with the channeled face of said base, said block having thereon an electrical switching means for opening and closing a conductive path between two contact points, and channeled in said surface to provide channels adapted to support said contact elements, and wherein each of the contact elements adapted to contact wires in the outer channels of the base is electrically connected to one of said contact points.
body together; wherein one of said base member and body member is formed with wall means for defining an enlarged channel at one end of the component capable of receiving the sheath covered wires, said channel branching into three smaller intermediate channels capable of receiving insulated wires exposed by cutting away a short portion of said sheath, and converging again as an enlarged channel at the other end of said component, the central intermediate channel being substantially straight and the outer intermediate channels being oppositely arcuate, and wherein said base has wire-supporting means including wire-supporting surfaces extending along a portion of each of said intermediate channels relative to an appropriate one of said contact plate portions with the mouths of the slots of said plate portions centered in relationship to the wiresupporting means of said base while permitting entry of said contact plate portions into said base beyond said wire-supporting surfaces, whereby insulated wire conductors supported in said intermediate channels are brought into permanent positive electrical connection with appropriate contact plate portions upon engagement of the body with the base.
7. The electrical component of claim 6 wherein said body member comprises an elongate insulating block having a surface mating with the face of said base, said block being slotted through said surface to an opposite surface to provide at least one pattern of holes corresponding to the projections on a 3 conductor power plug and channeled in said surface to provide channels adapted to support said contact elements, and wherein each of said contact elements is further characterized by having a slotted plug-receiving portion positioned on said contact element in its supporting channel with said plug-receiving portion in alignment with one of said holes.