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Publication numberUS3389367 A
Publication typeGrant
Publication dateJun 18, 1968
Filing dateMar 25, 1966
Priority dateMar 25, 1966
Publication numberUS 3389367 A, US 3389367A, US-A-3389367, US3389367 A, US3389367A
InventorsSchwartz Frederick W
Original AssigneeCable Electric Products Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Safety cap for extension cord sets
US 3389367 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

June 18, 1968 F. w. SCHWARTZ 3,389,367

SAFETY CAP FOR EXTENSION CORD SETS Filed March 25, 1966 INVENTOR FREDERICK W. SCHWARTZ BY I AT TOiEY United States Patent "ice 3,389,367 SAFETY CAP FOR EXTENSION CORD SETS Frederick W. Schwartz, Providence, R.I., assignor to Cable Electric Products, Inc., Providence, R.I., a corporation of Rhode Island Filed Mar. 25, 1966, Ser. No. 537,461 4 Claims. (Cl. 339-38) ABSTRACT OF THE DISCLOSURE A safety cap for an extension cord comprising a plurality of flat rectangular portions integrally connected by flexible webs. The central portion is provided with a restricted slot for receiving the extension cord to mount the safety cap. The outer portions are provided with spaced parallel flat tabs which enter the slotsin the electrical tap to be frictionally retained therein and to dielectrically close the slots.

My present invention relates to electrical cords and terminals and more particularly to a novel safety cap for an extension cord.

The principal object of the present invention is to pro vide a safety cap for a multiple outlet terminal on an electrical extension cord.

A further object of the present invention is to provide a simple device mounted on the terminal cord for plugging one or both of the free outlets on a multiple outlet cord.

Another object of the present invention is to provide a safety cap or plug device which is independently operated but can readily be attached to the multiple outlet extension cord.

Another object of the present invention is to provide a safety cap which is comparatively inexpensive to manufacture and can be readily assembled with the safety cord at a minimum of cost.

Another object of the present invention is to provide a safety cap which is frictionally retained within the outlet portions so that a small child cannot readily remove it from the extension cord.

With the above and other objects and advantageous features in view, my invention consists of a novel arrangement of parts more fully disclosed in the detailed description following, in conjunction with the accompanying drawings, and more particularly defined in the appended claims.

In the drawings,

FIG. 1 is a perspective view of a multiple outlet at the end of an extension cord equipped with the safety cap of the present invention.

FIG. 2 is a rear view .of the same.

FIG. 3 is a side elevation thereof.

FIG. 4 is a perspective view of the safety cap.

Small children are extremely curious. Especially babies at the crawling stage have been known to push all types of objects into wall receptacles and getting severely injured by the electric shock. To prevent this, safety plugs are used so that wall outlets not occupied with an extension can be closed up and sealed by means of a dielectric plug. These plugs are removable when it is desired to actually use the outlet. However, where extension cords are used to reach a lamp or other appliance, the unused portions of the multiple terminal present the same hazards as the empty wall outlet. To this end, the present invention is designed to provide a safety cap which is readily mountable on an extension cord and is designed to plug up the unused portions of the multiple outlet so as to protect children from injury.

Referring more in detail to the drawings embodying my invention, FIG. 1 illustrates a conventional extension cord assembly having a dual wire extending from a standard 3,339,367 Patented June 18, 1968 plug, not shown, for insertion into a wall socket, and a multiple female terminal 11 mounted at the end of the cord 10. The terminal 11 and cord 10 are assembled in a conventional manner and preferably with the terminal 11 molded of vinyl plastic material and molded to the end of the cord 10. The terminal 11 is of conventional design having a front wall portion 12 with the pair of spaced terminal openings 13 for receiving the plug at the end of the appliance or lamp. The center of the multiple terminal 11 is provided with the transverse portion 14 having openings at each end to provide two additional spaces for receiving two additional plugs. These are the openings that are usually left open when only a single appliance is attached to the front of the extension cord.

In accordance with the present invention I provide a safety cap such as illustrated in FIG. 4. This comprises a plastic, dielectric member 15 molded in integrally connected flexible sections so that it can be mounted on the electrical cord 10 and extend over and into the opposed slots on the section 14 of the terminal. The member 15 is thus molded with a central rectangular comparatively thick portion 16 having adjacent interconnected central openings 17 adapted to grip the cord lead connection 10 as shown in FIG. 2. A slot 18 extends from one side edge and communicates with the portion 17 so that the member 15 can be slipped on to the electrical cord connection 10 by means of the slot 18 which is tight but will give resiliently to permit a snap assembly. Adjacent opposite sides of the central member 16 are similar comparatively thick plastic members 19 and 20 each integrally connected to an edge of the member 16 by a thin flexible membrane 21. By moulding the plastic material thin at the portions 21 they will easily flex whereas the members 16,. 19 and 20 are molded thicker and are more rigid.

At the outer ends, the member 19 is connected to another thick portion 22 by an integral flexible web portion 23. The member 20 is connected to an end portion 24 by an integral flexible web portion 25. The outer edges of the portions 22 and 24 are tapered at 26 to provide a finger engaging edge. The portions 22 and 24 are molded with integral elongated rectangular tabs 27 extending at right angles from each side edge, see FIG. 4. The width of the member 15 is such that the spacing between the members 27 is approximately equals to the spacing between the plug openings such as 13. However, the fit is tight, with the spacing slightly smaller so that the members 27 will grip the inside edge of the plug openings. This accentuates the friction between the two plastic elements, the member 11 and the member 15.

Now when the member 15 is mounted on to the cord lead connection 10 as shown in FIG. 2 with the cord extending through the slot 18 and into the Openings 17, it will be found that pressure on the portions 22 and 24 will force the members 27 into the opposed slots into the position shown in FIGS. 1 and 3. Since there is friction between the elements, some pressure is necessary and the parts will resist separation so that a small child or baby will not be able to remove the safety cap 15. The flexible connections between the members 16, 19, 20, 22 and 24 permit adjustment of the rear member 16 in sliding along the cord 10 'when the members 27 are forced into the openings. This takes care of any variations in the length of the member 15 and allows manufacture without regard to close tolerances. If it is desired to use any of the cross contact portions of the element 11, it is merely necessary to place the thumb or finger under the end 26 of either the topor bottom member 22 or 24 and lift. the portion out of the particular cord plug openings. In this connection it should be noted that if one portion is lifted out the other one still remains in place so that each end of the safety cap can be independently operated without disturbing the other end.

The cap 15 can readily be molded in a single piece at small cost. To assemble it to the conventional cord lead connection it is merely necessary to slip the cord through the slot 18. Therefore, the safety cap and its assembly adds very little to the general overall cost of the extension cord.

It should be noted that the safety feature of the cap of the present invention is concentrated in the end portions 22 and 24 with the extending tabs 27. The balance of the construction is designed to mount the safety cap on the device so that it is always present and ready for use. To this end the connecting portions 19 and 20 and even the rear panel 16 may be made of thin flexible membrane or any other type of connection. The illustrated construction is designed to provide safety plus strength so that if the device is stepped on or otherwise abused it will not be dislodged or broken. Other advantages of the present invention will be readily apparent to a person skilled in the art.

I claim:

1. In an extension cord in which a length of two conductor electrical cord is provided with a contact plug at one end and a multiple tap at the other end having a pair of flat longitudinal plug receiving slots and a pair of fiat transverse slots adapted to receive a contact plug at each end, a safety cap for said transverse slots comprising a dielectric member mounted on said extension cord, and in which said dielectric member comprises a plurality of fiat rectangular portions integrally connected by flexible webs, and means on said member for plugging the outer ends of said transverse slots when not in use.

2. A safety cap as in claim 1, in which one of said rectangular portions is provided with a restricted slot for frictionally receiving said extension cord to mount said member on said extension cord.

3. A safety cap as in claim 1, in which said means comprises spaced fla-t dielectric tabs extending at right angles from said member and adapted to frictionally enter and plug said transverse slots.

4. A safety cap as in claim 3, in which said member is provided with a restricted slot for frictionally receiving said extension cord to mount said member on said extension cord.

References Cited UNITED STATES PATENTS 1,978,510 10/1934 Spence 339-36 2,407,894 9/1946 Miller 33938 2,753,536 7/1956 Tjader 339103 3,275,969 9/1966 Sheeran 339-103 FOREIGN PATENTS 465,837 6/1950 Canada.

MARVIN A. CHAMPION, Primary Examiner.

J. H. MCGLYNN, Assistant Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1978510 *Aug 15, 1931Oct 30, 1934Remac Patents CorpElectrical cable connecter socket and contacts
US2407894 *Nov 24, 1941Sep 17, 1946Mines Equipment CompanyElectrical connecting unit
US2753536 *Jul 27, 1953Jul 3, 1956Hugo TjaderClamps for holding electric connectors together
US3275969 *Nov 2, 1964Sep 27, 1966Victor Electric Wire & Cable CWire shortening and tying device
CA465837A *Jun 13, 1950Dancyger Mfg CompanyShield for electric plug
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3876273 *Jul 5, 1973Apr 8, 1975Cable Electric Products IncElectrical safety service block
US4396245 *Mar 12, 1981Aug 2, 1983Amp IncorporatedCover for multiple terminal electrical connector
US4408813 *Sep 4, 1981Oct 11, 1983Noma Canada Ltd.Multiple outlet and cover therefor
US4806112 *Oct 1, 1987Feb 21, 1989Tronomed, Inc.Safety adapter for electrical connector housings
US5017148 *Oct 4, 1990May 21, 1991Buckshaw Dennis JSafety cap for electrical outlet
US5096430 *Feb 12, 1991Mar 17, 1992Amico Ralph E DCovering electrical sockets for safety
US5236369 *Aug 3, 1992Aug 17, 1993Beach Sandra GElectrostatic latent image
US5238416 *May 28, 1992Aug 24, 1993Paige Manufacturing Corp.Extension cord receptacle
US5320542 *May 7, 1993Jun 14, 1994Cheng Yu FSafety cover for sockets
US5320543 *Jun 28, 1993Jun 14, 1994Barton Craig SFlexible plug protector
US5370542 *Aug 11, 1993Dec 6, 1994Beach; Sandra G.Holder for electrical safety caps
US8007321 *Oct 6, 2010Aug 30, 2011Cheng Uei Precision Industry Co., Ltd.Earphone adapter
WO1994029931A1 *Jun 7, 1993Dec 22, 1994Paige Mfg CoExtension cord receptacle
U.S. Classification439/148
International ClassificationH01R13/44, H01R31/00, H01R31/02, H01R13/443
Cooperative ClassificationH01R13/443, H01R31/02
European ClassificationH01R13/443