Electric plug

Dec. 11, 1945.

2,390,852

E. C. STEE

ELECTRIC PLUG

Filed Jan. 16, 1943

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Attorneyi

Patented Dec. 11, 1945

2,390,852

UNITED STATES PATENT OFFICE

2,390,852

ELECTRIC PLUG

Ernest C. Stee, Bismarck, N. Dak.

Application January 16,1943, Serial No. 472,625

Claim. (Cl. 173—361)

The present invention relates to new and useful improvements in electric attachment plugs and has for its primary object to provide, in a manner as hereinafter set forth, a novel construction and arrangement whereby the device will be held firmly in the receptacle or socket and good electrical contacts maintained at all times.

Another very important object of the invention is to provide an electric plug of the aforementioned character wherein the prongs may be expeditiously removed from the body or shell to facilitate connecting conductor wires thereto, and then replaced.

Other objects of the invention are to provide an electric plug of the character described which will be comparatively simple in construction, strong, durable, highly efficient and reliable in use, compact, attractive in appearance and which may be manufactured at low cost.

All of the foregoing and still further objects and advantages of the invention will become apparent from a study oi the following specification, taken in connection with the accompanying drawing wherein like characters of reference designate corresponding parts throughout the several views, and wherein:

Figure 1 is a perspective view of an electric plug constructed in accordance with the present invention.

Figure 2 is a view in side elevation thereof.

Figure 3 is a sectional view, taken substantially on the line 3—3 of Figure 2.

Figure 4 is a detail view in perspective of the resilient, removable prong-retaining block.

Referring now to the drawing in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a substantially flat body or shell i of hard rubber or other suitable insulating material. The shell I includes a substantially dovetail inner portion constituting a grip 2 the longitudinal faces of which are knurled or roughened, as at 3. The grip 2 further includes oppositely inclined ends 4.

As illustrated to advantage in Figure 3 of the drawing, the body I has formed therein a chamber 5. A comparatively narrow entrance passage 6 communicates with the chamber 5, the side walls of said entrance having formed therein sockets or depressions 7. The other end portion of the body I has formed therein an opening 8 which communicates with the chamber 5, which opening accommodates the conductor cord. The front 9 of the body I has formed therein a slot 10 which communicates with the chamber 5. The purpose of the slot i0 will be presently set forth.

Pivotally mounted in the body i and projecting therefrom is a pair of removable, normally diverging prongs II. Intermediate portions of the prongs f I are formed to provide substantially ushaped, laterally projecting trunnions 12 which are journaled in the sockets 7. A substantially wedge-shaped block 13 of resilient rubber is inserted and compressed in the entrance 6 between the prongs 11 for retaining the trunnions 12 in the sockets 7.

The inner end portions of the prongs 11 have formed therein openings i 4 for the passage of the skinned end portions of the electric wires 15. Threadedly mounted in the prongs 11 are binding screws (6 for firmly securing the wires 15 to said prongs.

It is thought that the manner in which the plug functions will be readily apparent from a consideration of the foregoing. Briefly, the resilient block (3 normally holds the prongs 11 in substantially the position shown in Figure 3 of the drawing. Thus, the outer ends of the prongs 11 are too far apart to enter the usual socket or receptacle. To connect the plug, the prongs I ( are pressed inwardly or toward each other for engagement in the receptacle, thereby compressing the resilient block (3. In this manner the prongs ί ί are constantly pressed outwardly or apart for firmly securing the plug to the receptacle and for maintaining good electrical contacts. Of course, the prongs 11 fulcrum or rock in the sock, ets 7. To remove the prongs ί ί from the body I for connecting the wires thereto, the resilient block (3 is dislodged by inserting a suitable instrument through the slot 10. Removal of the block ί 3 permits disengagement of the trunnions i 2 from the sockets 7 for withdrawing the prongs ί I from the body I.

It is believed that the many advantages of an electric plug constructed in accordance with the present invention will be readily understood and although a preferred embodiment of the device is as illustrated and described, it is to be understood that changes in the details of construction may be resorted' to which will fall within the scope of the invention as claimed.