Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS3662296 A
Publication typeGrant
Publication dateMay 9, 1972
Filing dateApr 20, 1970
Priority dateApr 20, 1970
Publication numberUS 3662296 A, US 3662296A, US-A-3662296, US3662296 A, US3662296A
InventorsAlbert P Newman
Original AssigneeKdi Sealtron Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Safety electrical connector
US 3662296 A
A safe electrical connector assembly is provided for engaging with a mating connector, either or both connectors terminating an electrical cable, the safe electrical connector assembly including an insulating housing and therein a male contact portion having a concentric non-conductive cap. The male contact portion is disposed within a passageway in the housing of an assembly, the cap and the restricted clearance between male contact and passageway cooperating to prevent dangerous exposure to electrical surfaces.
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent Newman [15] 3,662,296 [4 1 May 9, 1970 [54] SAFETY ELECTRICAL CONNECTOR [72] Inventor: Albert Newman, Springfield Township, Hamilton County, Ohio [73] Assignee: KDI Sealtron Corporation, Cincinnati,


[22] Filed: Apr. 20, 1970 [21] Appl. No.: 29,873

[52] U.S. Cl. ..339/36, 339/91 R, 339/195 R [51] Int. Cl ..HOlr 13/52 [58] Field oiSearch... ..339/3639, 94,

[56] References Cited UNITED STATES PATENTS 2,698,926 1/1955 Young ..339/91 R 2,716,737 8/1955 Maberry ..339/31 R 3,375,480 3/1968 Nelson ..339/38 Phillips ..339/1] 1 R Link ....339/60 C Primary E.\'aminer-Marvin A. Champion Assistant Examiner-Terrell P. Lewis Attorney-John W. Melville, Albert E. Strasser, Stanley H. Foster, Joseph V. l-lofiman, Gibson R. Yungblut. Charles H. Melville and John D. Hayes [57] ABSTRACT A safe electrical connector assembly is provided for engaging with a mating connector, either or both connectors terminating an electrical cable, the safe electrical connector assembly including an insulating housing and therein a male contact portion having a concentric non-conductive cap. The male contact portion is disposed within a passageway in the housing of an assembly, the cap and the restricted clearance between male contact and passageway cooperating to prevent dangerous exposure to electrical surfaces.



This invention relates to electrical connectors and more particularly to an electrical connector device which can be used to terminate an electrical cable length and enable it to be coupled with another cable length, the particular device here provided being characterized in that it makes for a connector safe for users.

2. Description of the Prior Art.

In many industrial applications, in manufacturing plants and elsewhere, it is necessary for operation that temporary electrical connection be made. A permanently emplaced connector in the nature of an electrical cable end hanging free in the vicinity of the work or a fixed electrical receptacle in the work area may be provided. A movable appliance, machine, or other operating device which from time to time is moved into and out of the work area, its place being taken by an altemative device, will be the device requiring removable electrical connection to such permanently emplaced connector. Such device would have as part thereof an electrical connector for mating with the permanently emplaced connector. The permanently emplaced connector in this kind of arrangement continuously carries power, and for this reason it is necessary to make provision to protect the workman or passerby when such a hot" connector is temporarily out of engagement with a mating connector.

The practice in the past generally has been in arrangements where temporary electrical connection may be made, that such permanent connector be a female connector. Means for. protecting workmen and passers-by from accidental contact with such a connector are well known in the art. For example, a spring loaded cover to overlaythe connector may be employed. Such means for protection, however, invariably suffer from the drawback that a separate unit of some variety is designed to cooperate with the female connector for purposes of preventing contact with electrified surfaces, though sometimes the protective means is incorporated right into the female itself. Whatever the arrangement, significant additional expense is incurred for purposes of achieving the required safety.

SUMMARY OF INVENTION The primary object of the present invention is to provide an electrical connector for releasable interengagement with another connector, which, while continuously electrified, is characterized by the safety afforded to persons who may come into contact with it. A male connector rather than a female connector is employed and the male connector is surrounded by an insulating housing. The contact portion in the male connector is surrounded by and spaced from the insulating housing, and the contact portion of a female connector may be moved into interengagement with the male connector. Such spacing is of such dimension that it will not admit of the introduction of a persons finger. The Contact portion of the male connector terminates in a dielectric cap which effectively shields the end of the connector. The cap together with the restricted spacing prevents injury by accidental electrical shock to users. While it is difficult and expensive relatively speaking to protect users where, as has been the practice in the past, it is the female connector which continuously carries power, I have found it simpler, more effective and safety more positive where a male connector having the structure here provided is so employed as the continuous power carrier.

DRAWINGS FIG. 4 is an enlarged section taken at 4-4 in FIG. 2;

FIG. 5 is a side view partially in section of a female connector assembly for interengagement with the male connector assembly of FIG. 1;

FIG. 6 is an end view of the female connector assembly seen in FIG. 5;

FIG. 7is an enlarged view of a portion of the end view of FIG. 6; and

FIG. 8 is a fragmentary bottom view partially in section of a portion of the housings in the male and female connector assemblies showing latching means for releasably securing said assemblies together.

DESCRIPTION In the drawings, male connector assembly 10 is shown. Such assembly is designated male because it houses connectors 11 therein, each of which has a male contact portion 12, as well as cable retainer portion 13. The connectors 11 are retained within an insulating housing 15 which entirely surrounds such connectors and prevents Contact of them by outside surfaces. The insulating housing 15 is preformed of a flexible insulating material such as neoprene, and the connectors may be placed within them when it is desired to make an installation utilizing them. A collar 16 molded within housing 15 for engagement with a pin 16a on connector 11, such expedient being more fully shown in my co-pending application, Ser. No. 70l,242 now abandoned, may be utilized as the means for retaining connector 1 1 within housing 15.

The disposition of connectors 11 as illustrated within the housing will follow connection between cable retainer portion 13 and the conductive strands 17 of an electrical cable 18. Such connection, in a manner long familiar in the art requires stripping of the insulation from cable 18 to expose the conductive strands 17, followed by insertion of the strands into recess 20 in cable retainer portion 13, the strands being therein retained either by deforming portion 13 as by crimping, or by screwing down a set screw. The connector 1 1 with cable 18 attached may then be drawn into the housing 15 by means well known in the art. It may be done by pushing housing 15 up on cable 18 prior to securing connector 11 to the cable, then, after strands 17 are secured to connector 11, pulling the housing down so that connector 11 enters the housing, cable retainer portion 13 first, until engagement with collar 16 is reached.

Returning now to further description of connector 11 particularly with reference to male contact portion 12, such portion is split at 21 and the contact portion employed generally is disclosed in my co-pending patent application Ser. No. 873,248, though the present invention employs substantial modifications of the structure disclosed in such prior application. As in my said prior disclosure, a Belleville washer 22 is pinned within split 21 by drive stud 23.

A cap 24 of non-conductive material is fixed at the end of male contact portion 12. The means for fixation is the formation of such portion 12 with a projection 25 extending from the end thereof. Projection 25 is disposed within recess 26 in cap 24, cap 24 being there fixed in place by means of a pin 27 which transfixes both cap 24 and projection 25.

Male connector 11 lies within passageway 30 in housing 15. Housing 15 has a portion of reduced outer dimension 30a (by Contrast to the main body of housing 15 as at 30b which has a larger outer dimension). Passageway 30 passes through the entire length of housing 15. Male contact 12 and cap 24 are disposed within that portion of the passageway 30 within portion 30a of housing 30. As may be observed in the drawings such passageway 30 is of larger size than the male contact portion 12 laying within it. The spacing between housing and contact portion will here and in the claims be referred to as safe spacing and where this term is employed it will be understood that what is contemplated is such spacing as will not permit admission of a human finger. Such dimension cannot be stated with precision, but I believe that a dimension of not more than about three-sixteenths inch would be called for for SAFE spacing."

' is formed with a convex surface 46,

As has been stated, the safety connector here provided utilizes a male connector. It will be understood that such a con nector is employed with a mating female connector assembly 31 as is shown in FIGS. -7. Female connector assembly 31 contains connectors 32 each having female contact portion 33 (to receive therein male contact portion 12 of connectors 11). Each connector 32 is conventional electrical engagement with an electrical cable 33a as by stripping the cables, then crimping or screwing the conductive portion of the cable down within the connector 32. Such assembly 31 includes also housing 34.

Housing 34 has a raised external portion 35, which portion 35 provides a means whereby the female connector assembly 31 can be secured to, for example, a panel 36. Bracket 37, which bears against shoulder 38 in raised portion 35 provides the means for securing housing 34 to a panel, and the bracket 37 is fastened to panel 36 by means of bolts 39.

- A significant element of configuration of the respective housings, which elements cooperate to prevent engagement of male and female connector assemblies other than in the desired polarity, can be seen in the drawings. These consist of a concave surface 44, in portion 30a of housing 15 which is reduced in outer dimension so that it may be embraced within overlying portion 45 of housing 34. Such overlying portion 45 so that interengagement of the two assemblies is only possible when convex surface 46 registers with concave surface 44, and thereby proper mating of electric lines of proper polarity is guaranteed.

It will be appreciated that interengagement of the male connector assembly and female connector assembly 31 involves simultaneous interengagement of male contacts 12 with female contacts 33 and also of portion 30a of housing with overlying portion 45 of housing 34. As is shown in the drawings, the inter-engaging male and female contacts 12 and 33 respectively move simply axially in order to reach engagement. While the particular connectors employed and disclosed and claimed in co-pending patent application Ser. No. 873,248 will not readily separate when this is not desired intentionally, nevertheless, a positive releasable locking means is provided here. Such releasable locking means consists of a sleeve 50 molded into housing 34, such sleeve being rigid, preferably of metal, and having incorporated into its sidewall a pin 51.

The male connector assembly housing '15 has moldedthereinto for rotatable movement a shaft 52. The shaft has a forward portion in which is formed a flat surface 53 and a circumferential cam path 54. A handle 55 is rigidly integrated into shaft 52, so that manipulation of such handle 55 will cause rotation of shaft 52. When handle 55 is in the position shown in solid lines in FIGS. 1 and 2, flat surface 53 in shaft 52 is ready to pass beneath pin 51 in sleeve 50in the female housing 34. l-landle55 must be in this position in order to permit the male connector assembly 10 and female connector assembly 31 to be interengaged. Following interengagement handle 55 is moved to the position shown in section lines in FIGS. 1 and 2, and this motion will serve to lock pin 51 in cam path 54. in this condition, the two connector assemblies cannot be separated. The handle 55 thus provides a visual signal for the user who can easily tell whether the connectors are in condition for interengagement; whether they are locked upon engagement; and whether they are in condition for separation after engagement when separation may be desired.

While the present invention has been illustrated in a specific embodiment as required by law, it is apparent that changes and modifications may be made therein, and as so changed or modified the resulting structure may still fall within the ambit of my invention.

1 claim:

l. A safety electrical connector assembly for usage wherein said assembly is continuously electrified comprising:

connector means,

a male contact portion in said connector means,

a cap of non-conductive material fixed upon an end of said male contact portion, said cap being of not greater cross sectional dimensionthan said male contact portions, and

a preformed insulating housing having a passageway therethrough, said male contact portion being wholly disposed within said passageway and said cap being disposed at least in part within said passageway, said male contact portion and said cap being spaced from the wall of said bore by an amount no more than three-sixteenths inch.

2. The safety electrical connector assembly claimed in claim 1 including:

a source of electrical power, and

an electrical cable at one of its ends being in electrical connection with said source, said assembly being electrically mounted on the other end of said electrical cable.

3. The safety electrical connector assembly claimed in claim 2 wherein said male contact portion and said cap are substantially circular in cross section and including means in said male contact portion for enabling axial releasable electrical engagement thereof with a mating female contact portion.

4. The safety electrical connector assembly claimed in claim 3 wherein said male contact portion is split into two parts and integral projection means extends from one of said parts, said cap being fixedly mounted upon said projection, said male contact portion and said cap being concentrically and axially disposed relative to each other.

5. The safety electrical connector assembly claimed in claim 2 including a second electrical connector assembly in combination therewith, said second assembly being electrically mounted at the end of a second cable, said second assembly comprising:

a second preformed insulating housing having a passageway therethrough,

second connector means disposed within said passageway in said second housing, and

a female contact portion in said second connector means,

said male contact portion and said female contact portion being in electrical engagement. 6. The safety electrical connector assembly as claimed in claim 5 wherein said first housing has an external wall and said second housing has a portion overlaying said external wall to protect said connector means and second connector means from external deleterious media.

7. The safety electrical connector assembly as claimed in claim 6 including:

latch means on said housings comprising a recessed sleeve molded into one of said housings, a cam pin extending from a wall within said recess,

a cam member having a'cam surface therein for engaging said cam pin, said cam member being rotatably mounted in the other of said housings, and

a lever mounted on said cam member, said lever being rotatably minipulable from a first position in which said cam member may be withdrawn from said sleeve, to a second position in which said cam surface and said cam pin and hence said housings are locked together, said lever providing a visual signal as to whether said housings are locked together or may be separated.

* IIK l l 0 UNKTED STATES PATENT OFFICE 569 CERTIFICATE OF CORRECTION Patent No. 3,662,296 v Dated May 9, 1972 lnventofls) Albert P. Newman It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

At the top of the first page the patent issue date of May 9, "1970" should read --1972--.

Signed and sealed this 12th day-of March 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2698926 *Dec 7, 1951Jan 4, 1955Sun Oil CoCable connector
US2716737 *Jun 17, 1952Aug 30, 1955Maberry Garland AElectric cable safety connectors
US3375480 *Dec 15, 1965Mar 26, 1968Winsco Instr & Controls CompanBlind plug for use with a fluid proof connector
US3384861 *Aug 25, 1966May 21, 1968Mc Graw Edison CoLoadbread device
US3474386 *Jun 10, 1968Oct 21, 1969Link Edwin AElectrical connector
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3781913 *Jun 8, 1972Dec 25, 1973Liburdi FElectrical safety block
US7442096Jan 17, 2008Oct 28, 2008Rig Power, LlcMale electrical connector
US7488224Dec 13, 2007Feb 10, 2009Cooper Technologies CompanySingle pole cable connector
US7695333 *Dec 11, 2008Apr 13, 2010Cooper Technologies CompanySingle pole cable connector
US7892047Apr 30, 2008Feb 22, 2011Cooper Technologies CompanySingle pole cable connector with tamper resistant locking mechanism
US8348693 *Nov 9, 2010Jan 8, 2013Virginia Panel CorporationElectrical connector interface with latch operated by threaded drive shaft
US8545275 *Dec 6, 2010Oct 1, 2013Alltop Electronics (Suzhou) Ltd.Electrical connector with touch-safety contact structures
US20110111619 *Nov 9, 2010May 12, 2011Stowers Jeffery PInterface
US20110250769 *Dec 6, 2010Oct 13, 2011Alltop Electronics (Suzhou) Co., LtdElectrical connector and electrical connector assembly with improved contact structures
WO2012038617A1Sep 20, 2011Mar 29, 2012Societe D'exploitation Des Procedes MarechalSingle-pole electrical connector having butt contacts
WO2013091990A1 *Nov 8, 2012Jun 27, 2013Robert Bosch GmbhElectric shock protection means for current-conducting connection elements
U.S. Classification439/135, 439/367, 439/915, 439/372
International ClassificationH01R13/44
Cooperative ClassificationH01R13/44, Y10S439/915
European ClassificationH01R13/44
Legal Events
Mar 7, 1989ASAssignment
Effective date: 19881221
Mar 7, 1989AS06Security interest
Owner name: CAM-LOK, INC.
Effective date: 19881221
Nov 14, 1986ASAssignment
Owner name: CAM-LOK, INC.
Effective date: 19860610