US1978805A - Electric service plug - Google Patents

Description

Oct. 30, 1934. A. s. M CLOY ET AL ELECTRIC SERVICE PLUG Filed Jan. 3,, 1933 ZZ/// W Patented Oct. 30, 1934 UNITED STATES PATENT OFFICE ELECTRIC SERVICE PLUG Application January 3, 1933, Serial a... 649,870

SCiaims.

In a copending application Serial No. 618,714, filed June 22, 1932, we have disclosed and claimed a two part electric service plug comprising a base having a pair of terminal prongs extending outwardly therefrom and provided with a conductor aperture disposed transversely of the prongs and a closure cap of elastic material tensioned over the base. The present application is in part a continuation of and in part an improvement on the invention referred to in our former application.

The present invention will be fully apparent from the following detailed description, when read in connection with the accompanying drawmg and will be defined with particularity in the appended claims.

In the drawing- .Fig. 1 is a side elevation of a plug embodying our invention;

Fig. 2 is a view from the right side of Fig. 1, the cushion closure cap being partly broken BI Y;

Fig. 3 is an inverted plan ofFig. 1;

Fig. 4 is a section on line 44 of Fig. 1; 2 Fig. 5 is a detail face view showingthe base of our improved plug;

Fig. 6 is a section on line 6-6 of Fig. 5;

. Fig. '7 is a cross section through the closure cap forming part of the plug;

Fig. 8 is a detail perspective view of one of the terminal prongs of the plug;

Fig. 9 is a. fragmentary detail view illustrating the manner in which the body of the base is distorted to facilitate securing the prongs in their operative position.

Referring in detail to the drawing, 10 represents generally the base of the plug. This base, in accordance with the present invention, is preferably formed of somewhat flexible or re- '40 silient insulating material, such as rubber, or

equivalent yieldable materials. It comprises an end wall 12 and a substantially cylindrical'side wall 14 having a lateral extension 16 provided.

with an aperture such as indicated at 18 for the 4 entrance of a flexible conductor cord 20.

Terminal prongs 22-22 extend through slots 24-24 formed inthe end wall-12, these prongs being adapted to engage the usual contacts of any suitable form of wall receptacle. Each. 5'!) prong, at its inner end, has an oblique or out- I wardly bent terminal portion 25, provided with a threaded aperture 26 for the reception of a terminal screw 28. Extending perpendicularly from each terminal portion 25, there is a pair .55 of oppositely disposed cars 30, which function to properly position the end of the conductor or wire engaged by the respective terminal screws 28.

As clearly indicated in Figs. 2, 4 and 5, we provided a barrier 32, which is molded in or forms an integral part of the base 10, this barrier substantially separating the interior chamber 34 of the base into two parts, in one part of which is located one of the terminals 24 and in the other part of which is locatedthe other terminal. The terminal prongs make a fairly snug fit with the slots 24 and because the body 10 of the base is formed of live somewhat flexible rubber, or similar material, a very effective friction grip is exerted on the prongs, by the T0 walls of the slot. But, in order to prevent the prongs 22 from being displaced when they are engaged or disengaged with contacts or jaws of a wall receptacle, .we provide means engaging the extremities of the prongs for positively preventing their displacement. This means preferably includes overhanging lugs, such as indicated at 36 in Figs. 4, 5 and 6. Reference to Fig. 4 will show that the oblique terminal portions 25 are disposed approximately at an angle of 45 to 86' the main portion of the prong and that the extreme outer edge of the terminal portion 25 abuts the lug 36, extending inwardly from the base. As thus arranged, it is clear that the application of an endwise force tending to push 5' the prong through the slot 24 will be resisted by the lug 36. And it is apparent from Fig. 4 that the oblique terminal portion coincides with the hypothenuse of the right angle formed by the inner annular surface of the wall 14 and 90 the inner flat face of the chamber 34 and as thus arranged the terminal will function as a strut or brace for the resilient side wall.

Inasmuch as the base 10 is made of rubber, or similar somewhat flexible material, it is desirable to provide means to assist the lug 36 in resisting the force transmitted thereto when the prong is pushed into engagement with a coacting contact. To these ends, I provide a resilient its projection 40, coacts with the lug 36 and the edge of the oblique terminal portion 24 to properly hold the prong in position. The thickness of the part of the base, in which the prong receiving slots 2c are formed, is suflicient to normally maintain the prongs in parallelism -and yet there is enough flexibility in the base to permit the prongs to yield a suflicient distance to compensate for inequalities in the spacing of the spring contacts of the wall, or other recep= tacles which they are adapted to engage.

If it were not for the fact that the basal!) of the plug were flexible, prongs of the shape shown could not be assembled, unless they were cast or molded. into position. The flexibility of this base greatly enhances the ease of assembly. In assembling, the end of each prong remote from the terminal portion is inserted through slot 24 and the annular wall is of the base is distorted, as indicated in Fig. 9, so as to permit the outer edge of the oblique terminal portion to clear the lug 36. This distorting-oi the parts can be accomplished by merely squeezing the annular wall 14, until it assumes an approximately elliptical shape. Such manipulation will deflect the lug 36 a sufiicient distance to iper= mit the oblique terminal portion to be moved into the assembled position of Fig. 4, whereupon the hand pressure will be released, thus permitting the resilient base to resume its inert position, as shown in Fig.4, in which position the lug 36 comes into abutting relationship with the outer extremity of the oblique terminal. portion. Y

While we have described quite precisely 'certain specific characteristics of the embodiment of the invention herein illustrated, it is to be understood that various changes may be made by those skilled in the art without departing from the invention as defined in the appended claims.

What we claim is: g

1. An electric service plug comprising a base of resilient material having an annular wall de-i dining a chamber, a prong extending through a slot formed in the base having a lateral terrninal portion, a lug projecting laterally from said thrust transmitted to'said lug by the prong,

wall d engaging the extremity of said term nal portion so as to prevent displacement of the prong relatively to the base and a closure cap of resilient material detachably tensioned over said base and having a portion engaging said lug.

2. An electric service plug comprising a'chambered base of resilient material having a lateral extension apertured for a conductor, a terminal prong extending through a longitudinal slot formed in the base, a lug on the chambered base adapted to hold the prong against endwise displacement and means detachably secured to the base having a part adapted to resist the when the prong is engaged with the contacts of a receptacle.

3. An electric service'plug comprising a base of resilient material having an annular wall defining a chamber, 9, prong extending through a slot formed in the base, said prong having an outwardly extending oblique terminal portion teting at said wall, said wall having an inwardly extending lug overhanging the end of said oblique terminal portion and a resilient cap having one part embracing said wall and, another part engaging said lug.

4. An electric service plug comprising "a chambered base of resilient material, a prong extending through a slot formed in said base, the inner extremity of the prong comprising an outwardly directed oblique terminal portion disposed within the chamber of the base and-carry= ing a terminal screw, an inwardly extending lug on the base coacting with the inner extremity of said terminal portion, said'base having an outer annular flange, a closure cap of resilient material having a part tensioned over said annular flange and also having an inwardly extending projection engaging said lug.

5. An electric service plug comprising a base v of resilient material having an annular resilient wall defining the chamber, prongs extending through slots formed in said base and having oblique terminal portions which engage and brace said resilient wall, lugs extending inward from said wall and engaging the ends of said terminal portions and a closure cap tensioned over said annular wall and having a portion engaging said lugs.

ARTHUR S. McCLOY. ST F. FRENCH.

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