Electric service plug

Oct. 30, 1934.

1,978,805

A. S. McCLOY ET AL

ELECTRIC SERVICE PLUG

Filed Jan. 3,. 1933

<img file="US1978805A_D0001.tif" />

Patented Oct. 30, 1934

1,978,805

UNITED STATES PATENT OFFICE

1,978,805

ELECTRIC SERVICE PLUG

Arthur S. McCIoy, Detroit, Mich., and Stanley F. French, Dobbs Ferry, N. Y., assignors to Anaconda Wire &amp; Cable Company, New York, N. Y., a corporation of Delaware

Application January 3, 1933, Serial No. 649,870

Claims. (Cl. 173—361) 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 60 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 located the other 65 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 70 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 prevent- 75 ing their displacement. This means preferably includes overhanging lugs, such as indicated at 36 in Mgs. 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 817 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 85 the prong through the slot 24 will be resisted by the lug 36. And it is apparent from Mg. 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 de- 95 sirable to provide means to assist the lug 36 in resisting the force transmitted thereto when the prong is pushed into engagement with a coact’ ing contact. To these ends, I provide a resilient closure cap, indicated as a whole at 38. This 100 cap has a centrally disposed inwardly extending projection 40, the peripheral part of which bears against the lugs 36 and thus contributes materially in resisting any force transmitted against the lug, when the prong is pushed into engage- 105 ment with its coacting contact. The closure cap 38 is formed with an inwardly extending flange 41, which with the adjacent portion of the body of the cap defines an annular groove 42. Π0

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 5 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 10 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 draw15 ing 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 away;

Mg. 3 is an inverted plan of Fig. 1;

Mg. 4 is a section on line 4—4 of Mg. 1;

Fig. 5 is a detail face view showing the base of bur improved plug;

Mg. 6 is a section on line 6—6 of Mg. 5;

Mg. 7 is a cross section through, the closure cap forming part of the plug;

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

Mg. 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 35 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 re40 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 45 entrance of a flexible conductor cord 20.

Terminal prongs 22—22 extend through slots 24—24 formed in the end wall 12, these prongs being adapted to engage the usual contacts of any suitable form of wall receptacle. Each' 50 prong, at its inner end, has an oblique or outwardly 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 ears 30, which function

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The base 10 of the plug is provided with an annular flange or bead 44, over which the flange 41 of the cap is adapted to be tensioned. When the parts are assembled, as shown in Fig. 4, it . 6 will be apparent that the resilient cap 38, with, its projection 40, coacts with the lug 38 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 10 receiving slots 24 are formed, is sufficient to normally maintain the prongs in parallelism and yet there is enough flexibility in the base to permit the prongs to yield a sufficient distance to compensate for inequalities in the spacing of Ϊ5 the spring contacts of the wall, or other receptacles which they are adapted to engage.

If it were not for the fact that the base 10 of the plug were flexible, prongs of the shape shown could not be assembled, unless they were §0 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 14 of the base is gg distorted, as indicated in Fig. S, so as to penult the outer edge of the oblique terminal portion to clear the lug 38. This distorting of the parts can be accomplished by merely squeezing the annular wall 14, until it assumes an approxigg mately elliptical shape. Such manipulation will deflect the lug 36 a sufficient distance to permit 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.

,yj 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 tjje appended claims