US2119810A - Electric plug - Google Patents

Description

June 7, 1938. 5 GRANT 2,119,810

ELECTRIC PLUG Filed Oct. 19, 1936 INVENTOR ATTORNEY v UNITED; STAT I Patented June 7, 1938 I My invention relates to wiring devices and more particularly to 'devicescommonly known as heater plugs which are employed to connect cur- 1 rent supply wires in circuit with electric heating 1 '5 appliances such as sad irons, waiile irons, bread toasters, etc'., and this application is a continuai tion in 'part of my pending application Ser. No.

] 42,762flledSeptember30,1935.. 1

, Heretofore plugs of this character have usual- 1 ly embodied-a casing iormed of a plurality of comating parts secured together by means of screws, bolts, or other metallic fastening devices.- A principal object oi my'invention is to provide. an improved heater plug in which the molded inl5 sulating casing is in onepiece.

A further object consists in providing .an improved plugof this character in which the several parts are compactly andconveniently arranged in combination'to facilitate assembly and to obtain a sturdy and well insulated device for the purpose. Other and further objects will appear from the following specification.

Referring to the drawing which forms a part hereof,

Figure 1 is a side elevation of a switchless heater plug embodying my invention.

Figure 2 is a vertical sectional view taken on line 2-2 oi Figure 1.

Figure 3 is a vertical sectional view taken on line 3-4 of Figure 2.

Figure 4 is a cross sectional view taken on line 4-4 of Figure 3 and showing an inverted plan of my resilient rubber wire guard.

Figure 5 is an elevation oi! the interior sub-as- 85 sembly carried in the casing of the device shown in Figures 1-4.

Figure 6 is a cross sectional view taken on line 6-6 of Figure 5 to show the improved binding terminal embodied in the modified device.

The insulating casing 10 consists of a deep molded shell of plastic composition having edge flanges l6 and side flanges I'I adjacent its top. The edge flanges are formed to provide a manual grip useful in withdrawing the plug to disconnect it and the side flanges define shoulders on opposite sides 01 the casing for engagement by the spring metal closure cap .60.

The lower end wall of the casing is apertured at 2l-2l to receive the contact prongs of an appliance with which it may be desired to make connection and the interior walls of the casing are molded to provide suitable shoulders and abutments for positioning and retaining the internal 5 parts 01' the device. Thus formed, the housing is to holdthe sub-assembly closely nested in the readily molded inv one piece and is of a" conven-y'v iently handy size and shape.

; The-interior partsoi' the device-constitute a sub-assembly; the combined-elementsoi which are adapted to, be drop'pedfinto' the casing in 6 close nested relatiomj- The sub-assembly, as shown in Figure 5, comprises ablock of insulating material. 15 carrying contact clipsfZ'V-it' secured to the block bysimilar eyelets 28" and are spaced to register with the openings 2|. 10 I ,One ofthe jaw'mernb'ersofeach contact clip extends above its respective eyelet 29' and the extended portion isxtransversely bent and bifurcated by a gradually tapering slot to form a bind.-

ingterminal ii, the wires'fl' being doubled or 5 knotted and pinched into the slot. As best shown in Figure 6, outer side edges of the binding terminals 3| are notched opposite the inner end of the slot to weaken the metal so that when a wire 32 is pressed into the tapering slot, the bifurgo cated portions'may yield slightly and, being resilient, grip the wire more firmly.

In this embodiment of my invention the wire guard 80 consists of a body of resilient material, such as a tough resilient rubber composition, g5 formed to provide a tubular sheath extending throughthe cap and adapted to surround and protect the insulating wires 32. The lower end of the guard is flanged to form an integral resilient cushion 8| which is compressed between the un- 30 derside oi the cap and the block and serves by virtue of its resilience to hold the cap bead'and flange securely against the casing' 'shouiders and easing. I I

As best' shownin Figure 4, the lower surface of the cushion is recessed on opposite sides to 'accommodate the wires and the recessed areas 82 are corrugated, the corrugations extending transversely to the wires whereby the wires are more 40 securely gripped against the top of the block 15, any strain on the outwardly extending portions of the wires being absorbedso that it is not trans- .mitted to the connections at'the terminals 3|.

To assemble the device, the closure cap and 46 wire guard are first threaded overthe wires and the wires are then connected to the binding terminals 3i. The sub-assembly is then dropped into thecasing and the closure cap is brought into engagement with the casing shoulders, there- 50 by compressing the resilient cushion -.8l against the top of the block, in which condition the cushion will tend toliit the cap and hold the cap bead and flange securely against the casing shoulders. To take down the assemblyit is only 6| necessary to pry the bead of the cap from under the casing shoulder, whereupon the cap and the block 15 may be freely removed.

Having thus described my invention, I claim:

1. A.heater plug comprising a deep molded casing of insulating material having exterior shoulders formed on its opposite sides adjacent its top, a closure cap oi resilient metal adapted to ,fit over the top of the casing and having inwardly extending edge portions adapted to engage said shoulders, conducting means carried within the casing, contacts carried by the casing and connected with said conducting means, said cap being perforate to admit current supply wires for connection to said means, and resilient means exerting an upward pressure on said cap to hold the edge portions thereof in engagement with said shoulders, said resilient means comprising an integral inner portion of a resilient rubber guard for said current supply wires extending through the cap perforation.

2. A heater plug comprising a one-piece casing of insulating material, a sub-assembly nested in the casing, a removable closure cap for the easing, and an insulating cushion of resilient rubber compressed between the sub-assembly and the cap to hold the sub-assembly firmly nested in the casing said cushion having a tubular portion integral therewith and extending through the cap for a considerable distance exteriorly thereof to provide a flexible guard for current supply wires.

3. A heater plug comprising a one-piece casing of insulating material, a, sub-assembly nested in the casing, said sub-assembly comprising a block

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