US1970968A - Electric service plug - Google Patents

Description

Fil ed June 22, 1932 I I .1: a. J 0 J 44 I Aer/Me 6f M0620) I JTA/YLEX fiFes/vcv/ 4 M'IE'ES/UENT INVENTORS ATTORNEYS '55 our invention;

Patented Aug. 21,

PATENT OFFICE ELECTRIC SERVICE PLUG Arthur S. McCloy, Detroit, Mich, and Stanley F. French, Dobbs Ferry, N. )L, assignors to Anaconda; Wire & Cable Company, New York, N. Y., a corporation of Delaware u Application June 22, 1932, Serial No. 618,714

7 Claims. (01. 173-361) This invention relates to so-called service or attachment plugs adapted for use in leading electric current to various household appliances, such as electric refrigerators, radios, electric toasters 6 and the like. Heretofore service plugs of this general character have been provided with terminal prongs extending generally in the direction of length of the longitudinal axis of the plug, and the connector cords or wires for carrying current to the terminal prongs of such plugs have usually extended in the same general direction as the prongs. Plugs of this character are adapted to be engaged with wall receptacles frequently secured to base boards or other parts of vertical walls. When the conductor cords extend in the same direction as the terminal prongs, they are disposed practically perpendicular to the wall or base board and if such cords are to be run horizontally alongside of the wall from the plug, there is a tendency to injure the wire due to the bending thereof. And when any strain is put on the conductor cord, there is a tendency to rock the plug as a whole, thus tending to loosen the engagement of its prongs vwith the ooacting contacts of the usual wall receptacle.

Plugs heretofore used have been frequently made of moldable insulating material and when such material is struck by moving furniture thereagainst, there is a tendency to break the base of the plug.

Our improved plug aims to overcome the above and other features of disadvantage which are inherent in plugs heretofore used. One object of our invention is to provide a plug in which 'the lead wire or conductor cord is disposed at an angle of substantially or approximately 90 to the direction in which the terminal prongs of the plug extend. A further object is to provide a service plug, the base of which is formed of moldable insulating material having a cap of resilientor cushioning material, so as to minimize the chance of breakage when the molded base is "struck by various articles of furniture and thellike. A further object is to provide a plug in which. the connecting wires enter through an aperture in the side wall of a chambered plug so that such wires need not be given sharp bends in order to have them run along an adjacentbase board or wall.

" The above and further objects will be apparent from the following specification when read in connection with the accompanying drawing.

In the drawing- I Fig. 1 is a side elevation of a plug embodying Fig. 2 is a view fromthe right side of Fig. 1, the cushion closure capbeing broken away;

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

Fig. 4 is a section on line 4-4 of Fig. 1;

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

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

Fig. 7 is an elevation with parts shown in section of the improved cushion closure cap forming part of the plug.

' Referring in detail to the drawing, 10 represents generally'the base of the plug. This base is preferably formed of moldable insulating material such as hard rubber or its equivalent. It comprises an end wall 12, a substantially cylindrical side wall 14 having a lateral extension 16, which is provided with an aperture, as indicated at 18 for the entrance of the flexible conductor cord 20. s

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 prong .22 has a pair of ears 26 which receive rivets or studs 28, which are molded or otherwise embedded in the end wall 12 of the insulating base. Each prong, carries a suitable terminal connecting means which in the embodiment illustrated comprises a screw 30, having an enlarged head such as commonly used, this head being adapted to be screwed down on the end of the conducting wire, for example, as indicated in Fig. 2.

As indicated in Fig. 6, it is clear that the apertured lug 16 is disposed substantially at a right angle to the longitudinal axis of the substantially cylindrical portion of the insulating base 14. Thus, the conductor cord 20 lies in a plane substantially parallel with the end wall of the base, this plane being perpendicular to the direction of length of the-terminal prongs 22. This disposition of the parts, it will be understood, provides an arrangement in which the conducting cord or wire is led through the opening in the side of the base, hence this cord can lie close to or run along the adjacent wall or base board without injuriously bending or straining the conductor.

The substantially cylindrical side wall 14 of the base provides a chamber 32 for accommodating the terminal screws 30 and the ends of the conductor wires. This chamber is closed by a cap 34, preferably formed of live rubber, which is adapted to be tensioned over an annular bead 36 formed on one extremity of the cylindrical wall 14: This cap, as best shown in Fig. '7, is provided with an annular groove 38, which is formed by are- 119 entrant annular flange portion 40. The inner central portion of the cap 34 is thickened, as indicated at 42, thus forming an annular seat 44, which is adapted to abut the outer ring-like surface 46 of the cylindrical wall 14 of the base.

This cap, which is formed of live resilient rubber or similar material, serves a double function. It constitutes a neat detachable closure for the chamber 32 formed on the base and it also serves as a resilient cushion to prevent breakage of the rigid base of the plug. This can, being formed of live rubber, has sufiicient elasticity so that it can be tensioned over the annular bead 36, thus it forms a substantially hermetical seal. This fact, coupled with the fact that the exterior of the conductor. cord 20 makes a tight fit with the aperture 18 and the fact that the terminal prongs 22 make a tight fit with the slots 24, serves to exclude air from the interior chamber of the plug, thus if there is any short circuiting, air or other combustion supporting gases are excluded and thus the fire hazard is lessened. The attachment plug described is relatively inexpensive to manufacture.- The closure cap being held in its place by its inherent elasticity requires no connecting screws or other elements apt to be lost or misplaced when making electrical connections with the prongs, this member being formed of live soft rubber provides a non-slip grip which is pleasing to the sense of touch. It has the further advantage of being non-conducting andalso physically isolated or out of contact with the conducting wires so that persons about a household unfamiliar with the handling of electrical appliances may confidently grasp the same without fear of receiving an electric shock.

While we have described quite precisely the detailed features of the embodiment of the invention illustrated it is to be understood that various modifications and substitution of equivalents may be made by those skilled in theart without departure from the invention as defined in the appended claims.

What we claim is:-

1. An electricservice plug comprising a rigid base of moldable insulating material formed with a chamber, terminal prongs extending from a point within the chamber outwardly from one end of said base, a conductor extending through the base at an angle to said prongs and connected to the latter within said chamber and an imperforate cap of soft elastic rubber or the like detachably embracing the end of said base opposite said prongs said cap having-an annular seat portion engaging the end of said base. a

2. An electric service plug comprising a rigid chambered base having terminal prongs extending outwardly from the chamber thereof, said base having an aperture substantially at right angle to the direction of length of said prongs, a conductor extending through said aperture and connected to said prongs and an imperforate cap tensioned over an end of said base and closing the chamber in said base.

3. An electrical service plug of the character described comprising a rigid chambered base having a pair of terminal prongs extending outwardly therefrom, the base having a conductor aperture therein disposed transversely to said prongs an annular bead on said base and an imperforate cushion tensioned over said bead at the end of the base opposite to that .end from which said prongs extend. a

4. An electrical service plug of the character described comprising a base of rigid insulating material having an end wall, a pair of terminal prongs projecting through slots formed in the end wall of the base, conductor connecting means secured to said prongs, a .side wall forming .part of the base and surrounding said connecting means, said side wall having a lateral conductor opening therein, and an imperforate cap of elastic material'in detachable engagement with said side wall and closing the end of the chamber formed by said end and side walls.

5. An electric service plug of the character described comprising a rigidbase of insulating material having anend wall, a substantially cylindrical side wall integral therewith and having a substantially radial conductor opening therein, terminal prongs secured to and projecting through said end wall, an annular bead on said end wall and an imperforate closure cap of elastic material having an annular portion in engagement with said bead.

6. An electric service plug of the character described comprising a base of rigid molded insulating material having an integral fiat end wall and a substantially cylindrical side wall, a lug extending laterally therefrom and having a conductor aperture therein, terminal prongs extending through the end wall and an imperforate closure cap of elastic material tensioned over the end of said side wall.

'7. An electric service plug comprising a base having an end wall and a side wall forming a chamber, a terminal prong piercing said end wall and having terminal connecting means within said chamber, a laterallyextending lug integral with said side wall and having a lateral aperture therein, a conductor-passing through said aperture connected to said terminal connecting means, and an imperforate detachable closure cap oftesilient material in tensioned engagement with said side wall.

a ARTHUR S. MCCLQY.

' STANIEY F. FRENCH.

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