US1951981A - Electrical connection - Google Patents

Description

March 20, 1934- J. LE R-JOHNSON ET AL ELECTRICAL CONNECTION Filed Nov. 22, 1932 2 Sheets-Sheet 2 FIE-E.

attorneys.

Patented Mar. 20, 1 934 UNITED STATES 1,951,981 ELECTRICAL CONNECTION Justus Le Roy Johnson, Lynwood, and Martin Geiszler, South Gate, Calif.

Application November 22, 1932," Serial No. 643,942

1 Claim.

the like being placed in the receptacle and cansing short circuits.

A further object is to produce a device wherein the standard practice of screwing a plug or bulb into a receptacle is maintained.

A still further object is to produce a device which will not materially increase the cost of manufacture.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numeralsare employed to designate like parts throughout the same, v

Fig. 1 is a cross sectional view of a wall type receptacle having a bulb positioned therein.

Fig. 2 is a fragmentary cross sectional view of the receptacle with the bulb removed,

Fig. 3 is a top plan view of the receptacle threaded element,

Fig. 4 is a side elevation oi Fig. 3, I

Fig. 5 is a view similar to Fig. 1; but showing a key type receptacle,

Fig. 6 is a side elevation of a bulb,

Fig. '7 is a sectional view of a keyless type re-' ceptacle, and

Fig. 8 is a perspective cross sectional view of a v plug for use withthe receptacle.

The ordinary receptacle has positioned therein a threaded element for engaging the stem of a bulb and a contact against which the end of the bulb engages. This contact and threaded element are each electrically connected to opposite sides of the power line and as a result the person can insert the fingers or a metal object into the receptacle and receive a shock or cause a short circuit, often-times with serious results. With our device this is impossible.

Referring to the drawings, and'particularly to Fig. 1, it will be noted that an insulated base 5 block 5 carries a bus bar 6 which is electrically connected to a line wire 7. A contact 8 is electrically connected to a line Wire 9. A cover block 11 is secured to the base Sand has a chamber 12 in which an insulating support 13 is positioned:

The cover block has an upstanding portion 14 which serves to house a threaded element 16 having a flange 17 provided with spring fingers 18. These spring fingers contact a shoulder 19 formed upon the cover block and to therefore normally hold the threaded element in'the position shown in Fig. 2. This threaded element has an open ing therethrough which has parallel sides (see Fig. 3) Within this opening is positioned a guide block 21, which rests upon the support 13 and is secured thereto. This guide block has parallel sides and therefore prevents the threaded elements 16 from rotating, but permits the same to slide thereon in a manner to be later described. Mounted within a bore formed in the guide block and support 13 is a spring pressed pin 22, held in the position of Fig. 2 by a spring 23.

In the form shown in Figs. 5 and '7 the construction is the same with the exception that the base block 5 is positioned within a receptacle casing 24 which casing of course is lined with insulation 26. This casing also surrounds the threaded element 16, which threaded element is normally held down by a spring 27 surrounding the guide block 21. The 'action of the spring 27 is similar to the action of the spring fingers 18. The key switch is designated as a whole by the numeral 28. As the remaining parts are identical the same numerals apply as those employed in describing Figs. 1 and 2. v

Referring to Fig. 6 it will be noted that the bulb 29 has a metal screw threaded element 31 and an insulating projection 32, which carries a contact 33, and by referring to Fig. 8 it will be noted that the plug 34 has a threaded element 36, an annular recess 35 and an insulating projection 3'7, which projection carries a contact 38,

-which contact is electrically connected by a wire 39 to a contact clip 41 and that the threaded element 36 is connected by a wire 42 to a contact clip 43. a

The result of this construction is that, assuming that the parts are in the position of Fig. 2, the threaded elements 16 will be held down upon the support 13 and consequently the flange 17 will be out of contact with the contact 8. At the same time the spring 23 will be holding the pin 22 in an elevated position and consequently its lower end will be out of engagement with the bus bar 6. When a bulb or a plug such as shown in Figs. 6 'or 8, respectively, is inserted in the receptacle, the screwing in of the bulb or the plug will result in thecontact 33 at the end of the insulating projection 32 of the bulb or contact 38 at the end of the insulating projection 37 of the plug, forcing the pin 22 downwardly against the tension of the spring 23 and into engagement with the bus bar 6, and at the same time pulling upwardly the threaded element 16 which rises upon the guide block against the tension of the spring fingers 18. Thereafter the flange 17 will be brought into contact with the contact 8, thus establishing a circuit from the bus bar 6, through the bulb and to the contact 8, for it is to be noted that the bus bar and contact are electrically connected to a source of energy. It will be apparent that the bulb will be energized or that the plug will be capable of delivering current as soon as a connection is made therewith. As soon as either the bulb or plug are removed the parts will return to their inoperative position of Fig. 2 and consequently the socket will be dead as far as the possibility of receiving a shock therefrom or short circuiting thereof, is concerned.

It is to be understood that the form of our invention herewith shown and described is to be taken as a preferred example of the same and that various changes relative to the material, size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claim.

Having thus described our invention, w claim:

In a device of the character described, a supporting block, a guide block positioned on said supporting block, a threaded element movable on said guide block, resilient means carried by said threaded element for normally maintaining said threaded element against said supporting block, means for preventing rotation of said-

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