US3629790A - No shock electric plug - Google Patents

Abstract

A sliding collar is secured to an electric plug having metal prongs by elastic means whereby the prongs are covered by the collar during insertion in and removal from an electrified socket.

Description

Mal-ted States Patent Inventor Frank D. McSherry, Jr.

McAlester, Okla. Appl. No. 95,304 Filed Dec. 4, 1970 Patented Dec. 21, 19711 Assignee The Raymond Lee Organization, Inc.

New York, N .Y.

N0 SHOCK ELECTRIC PLUG 4 Claims, 3 Drawing Figs.

U.S. Cl 339/42, 339/61 R Int. Cl 110- 13/44, H01r 13/60 Field of Search 339/36, 40,

References Cited UNITED STATES PATENTS Graham Staley Hudson Rubens... Brown Primary Examiner-Marvin A. Champion Assistant Examiner-Terrell P. Lewis 339/60 R X 339/42 339/60 R 339/42 339/42 ABSTRACT: A sliding collar is secured to an electric plug having metal prongs by elastic means whereby the prongs are covered by the collar during insertion] in and removal from an electrified socket.

NO SHOCK ELECTRIC PLUG BACKGROUND OF THE INVENTION Conventional electric plugs have metal prongs which are exposed during insertion in and removal from an electrified socket. These exposed prongs continue to conduct current until completely separated from the socket. A user can accidentally touch these prongs while still carrying current during such insertion or removal whereby the user can receive an electric shock and can be injured or even killed.

SUMMARY OF THE INVENTION My invention is directed toward a collar slidingly secured to an electric plug by an elastic which normally assumes minimum length and pulls the collar to a position at which the metal prongs of the plug are covered. As the plug is inserted in a socket, the elastic gradually lengthens and pulls the collar back to permit the prongs to be inserted into the female openings in the socket and yet cover the portions of the prongs not yet in the female openings whereby the plug can be properly seated without permitting the user to touch the prongs. When the plug is removed, the process is reversed and the elastic is gradually shortened, again without permitting the user to touch the prongs.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view of my invention;

FIG. 2 illustrates my invention in process of being inserted in or removed from a socket; and

FIG. 3 illustrates my invention seated in a socket.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIGS. 1-3, an electric plug comprises a head to which a two conductor cable 12 is connected with two outwardly extending electrically conductive metal prongs 14, each prong being connected to a corresponding conductor of the cable. The plug is to be seated in or removed from current carrying or electrified socket 16 in such manner as to prevent a user from accidentally touching the prongs.

To this end, a hollow electrically nonconductive circular cylinder 18 open at both ends serves as a collar and is slidable back and forth in the longitudinal direction about the outer periphery of the head I0. An elastic :strip 20 secured at opposite ends within the wall of the cylinder in such manner as to define a transverse diameter when in its normal or fully contracted position. In other words, the cylinder in cross section defines a circle and in the same view the strip forms a web spanning the circle and secured thereto at opposite points. This web extends between the prongs and is secured to the head at a point centrally intermediate the prongs.

As the plug is inserted in the socket, the strip elongates, pulling the collar rearward along the head to permit the prongs to be inserted in the socket and yet not be touched by the user. As the plug is removed, the strip contracts, reversing the above process, while still protecting the user as previously described.

While I have described my invention with particular reference to the drawings, such is not to be considered as limiting its actual scope.

Having thus described this invention, what is asserted as new is:

I. In combination with an electric plug having a head with a pair of electrically conductive prongs extending thereout:

an electrically nonconductive cylinder open at both ends,

said plug being slidable back and forth in said cylinder and said cylinder being slidable back and forth longitudinally along the plug; and

elastic means disposed in the cylinder and secured therein and to said plug, said means having a normal fully contracted position at which said cylinder extends beyond said prongs, said means being capable of bemg temporarily extended to expose portions of said prongs.

2. The combination as set forth IIIl claim I wherein said means is an elastic web or strip.

3. The combination as set forth in claim 2 wherein opposite ends of the strip are secured to corresponding oppositely disposed points on the cylinder.

4. The combination as set forth in claim 3 wherein the strip extends between the prongs and the center of the strip is secured to the head at a point centrally disposed between said prongs.

Claims (4)

1. In combination with an electric plug having a head with a pair of electrically conductive prongs extending thereout: AN ELECTRICALLY NONCONDUCTIVE CYLINDER OPEN AT BOTH ENDS, SAID PLUG BEING SLIDABLE BACK AND FORTH IN SAID CYLINDER AND SAID CYLINDER BEING SLIDABLE BACK AND FORTH LONGITUDINALLY ALONG THE PLUG; AND ELASTIC MEANS DISPOSED IN THE CYLINDER AND SECURED THEREIN AND TO SAID PLUG, SAID MEANS HAVING A NORMAL FULLY CONTRACTED POSITION AT WHICH SAID CYLINDER EXTENDS BEYOND SAID PRONGS, SAID MEANS BEING CAPABLE OF BEING TEMPORARILY EXTENDED TO EXPOSE PORTIONS OF SAID PRONGS.

2. The combination as set forth in claim 1 wherein said means is an elastic web or strip.

3. The combination as set forth in claim 2 wherein opposite ends of the strip are secured to corresponding oppositely disposed points on the cylinder.

4. The combination as set forth in claim 3 wherein the strip extends between the prongs and the center of the strip is secured to the head at a point centrally disposed between said prongs.

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