US3644867A

US3644867A - Grounded female socket and plug

Info

Publication number: US3644867A
Application number: US60673A
Authority: US
Inventors: Edward F Krause
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-08-03
Filing date: 1970-08-03
Publication date: 1972-02-22
Anticipated expiration: 1989-02-22

Abstract

A female socket having a plug-receiving or similar bodyreceiving opening which terminates in a plug-accommodating seat, and wherein the necessary positive and negative electrical contacts of the same are located about the socket opening while a ground electrical contact is advantageously located in the plugaccommodating seat. Accordingly, threaded engagement of the plug, lightbulb, or the like within the socket automatically results in operation of the same with the attendant safety factor of a connection to ground.

Description

waited States Patent Krause Feb. 22, 1972 [54] GROUNDED FEMALE SOCKET AND PLUG [72] Inventor: Edward F. Krause, 105 Birs Ave., Lindenhurst, NY. 11757 [22] Filed: Aug. 3, 1970 [21] Appl. No.: 60,673

[521 u.s.c|. ..339/14R,339/176L,339/183 [51] lnt.Cl ..H0lr3/06 5s FieldofSearch ..339/l4,59,182,183,176L,

[56] References Cited UNITED STATES PATENTS 2,170,131 8/1939 Doremus ..339/59 3,060,41710/1962 Blake 2,004,105 6/1935 Farish..... 2,118,857 5/1938 Morford 2,708,714 5/ 1955 Stevens ..240/54 Primary ExaminerMarvin A. Champion Assistant Examiner-Robert A. Hafer Attorney-Bauer & Amer [57] ABSTRACT A female socket having a plug-receiving or similar bodyreceiving opening which terminates in a plug-accommodating seat, and wherein the necessary positive and negative electrical contacts of the same are located about the socket opening while a ground electrical contact is advantageously located in the plug-accommodating seat. Accordingly, threaded engagement of the plug, lightbulb, or the like within the socket automatically results in operation of the same with the attendant safety factor of a connection to ground.

1 Claims, 4 Drawing Figures PATENTED FEB 2 2 I872 FIG! INVENTOR. EDWARD F. KRAUSE ATTORNEY GROUNDED FEMALE SOCKET AND PLUG The present invention relates generally to an improved combination female socket and plug, and more particularly to a female socket and plug construction which provides grounded operation for any electrical device electrically connected to the same.

While there are known prior art electrical devices which function both as a socket per se and also with an added female plug, none of these prior art devices, except those with unduly complicated constructions, provide the noteworthy safety factor of being grounded during electrical current transmission. The additional ground electrical contact and the requirement of establishing a grounding connection therewith invariably complicates the construction and mode of functioning of the combined socket and plug.

Broadly, it is an object of the present invention to provide a grounded combination socket and plug overcoming the foregoing and other shortcomings of the prior art. Specifically, it is an object to provide a threadably engageable cooperating socket and plug which has a ground connection during electrical current transmission that is established merely upon the threading of the plug within the socket.

The combined socket and plug electrical device demonstrating objects and advantages of the present invention includes in the areas of the socket and plug that make contact during threaded engagement of the plug within the socket a cooperating pair of ground electrical contacts in the preferred form of rings. Thus, the ground connection therebetween is established when the rings contact each other and is not critically affected by the tightness of the threaded engagement.

The above brief description, as well as further objects, features and advantages of the present invention, will be more fully appreciated by reference to the following detailed description of a presently preferred, but nonetheless illustrative embodiment in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:

FIG. I is a perspective view illustrating a typical use of the grounded female socket and plug hereof;

FIG. 2 is a side elevational view, in section and on an enlarged scale, illustrating internal structural features of the grounded female socket portion of the invention;

FIG. 3 is similarly a sectioned side elevational view, but illustrating internal structural features of the plug which is adapted to be threadably received in the socket; and

FIG. 4 is a front plan view of the plug.

Reference is now made to the drawings, and particularly FIG. 1, illustrating a typical use of the combination socket and plug hereof, generally designated 10, to provide an electrical connection for plural lights to a three-wire romex cable 12. Specifically, the device is illustrated in FIG. 1 in its contemplated form as a female socket 22 in which it threadably receives a lightbulb 14. Also illustrated in FIG. 1 is a modification of the device 10 wherein it includes in lieu of the bulb 14 a female plug 16 which is adapted to accommodate a male plug counterpart 18 of an electrical conductor 20.

As will be described in greater detail subsequently, a

noteworthy feature of the device 10, whether in the form of a female socket 22 or whether modified with the addition of the plug 16, is that in both forms the device 10 is grounded or, in other words, has a connection to ground which minimizes the possibility of a short circuit, electrical shock or similar mishap during use of the device 10. While there are known prior art electrical devices which function both as a socket per se and also with an added female plug, none of these prior art devices have the safety factor of being grounded during operation and yet have the simplified construction and other noteworthy features which characterize the device 10 hereof.

Referring to FIG. 2, the socket part of the device 10, more specifically designated 22, includes a plastic body 24 appropriately formed with a socket opening 26 for accommodating the base of the previously noted lightbulb 14 or the like, or the previously noted plug 16. The socket 26 terminates with an end counterbore 28 which provides a pair of transversely

oriented walls

30 and 32 which cooperate to define a seat for a peripheral projection of the plug 16, all as will be described in greater detail subsequently. At this point in the description, however, it is convenient to note that the base or inner end of the socket opening 26 is advantageously molded with threads which, in turn, readily permit the accommodation of a metal shell 34 having corresponding threads formed therein. The metal threads 34 serve as one electrical contact for the device 10 and is appropriately connected to a conductor 36 which, in practice, is affective in establishing an electrical connection to one of the three wires of the cable 12. The second metal contact 38, located at the extreme base of the socket opening 28, serves as the other electrical contact of the female socket 22. Contact 38 also is electrically connected to a conductor 40 through which electrical contact is established with another wire of the three-wire cable 12.

The ground connection for the device 10 which, according to the present invention, is embodied in the femalesocket 22, is in the form of a circular ring 42 which is appropriately force-fit in place within the end counterbore 28. Despite this exposed position of the ground contact 42, there is no added danger to the user because there is no current flow therethrough as there is in the case of the positive and negative

electrical contacts

34 and 38. The ground electrical contact 42, like the other

electrical contacts

34 and 38, is electrically connected to a conductor 44 through which an electrical connection is established between the ground 42 and the ground wire of the three-wire cable 12. As a consequence of the just-described construction of the female socket 22, a conventional threaded base of a lightbulb 14 in its threadably engaged condition within the socket 34 is effective in establishing the necessary positive and negative electrical connections with the

contacts

34 and 38 to cause operation of the lightbulb 14. Additionally, physical contact' is made with the ground electrical contact 42 to cause grounding of the electric bulb 14 during its operation and thereby providing the attendant safety factor which results from such grounded operation.

In accordance with the present invention, it is further contemplated that the female socket 22 will threadably accommodate the female plug 16 which, in turn, will accommodate the previously noted three-pronged male plug 18. To this end, plug 16 includes a large diameter base 46 having a smaller diameter forwardly projecting segment 48. At the front end of the segment 48 are cooperating positive and negative

electrical contacts

50 and 52 respectively connected via

conductors

54 and 56 to male prong-receiving openings 58 and 60 in the plug base 46.

Additionally, and as clearly illustrated in FIG. 3, at the juncture of the segment and base, there is a peripheral projection 62 which is of an appropriate radial extent to seat snugly in the seat 28, or-more particularly in the shoulder formed by the

transverse walls

30 and 32. Advantageously provided on a radial wall of the projection 62 is an electrical ground contact 64, in the preferred form of a ring, which cooperates with the previously noted ring 62 in establishing a continuation for the plug 16 of the ground electrical connection of the socket 22. This electrical connection is completed by a conductor 66 which is electrically connected from the ground contact 64 to a shaped male plug prong-receiving opening 68 which is provided in the plug base 46.

From the foregoing, it should be readily appreciated that there has been described herein a combination grounded female socket and plug 10 which provides a grounded electrical connection whether used merely as a socket or with the plug addition. Moreover, when the plug 16 is provided with its seated position within the socket 22, this automatically results in physical contact of the cooperating ground

electrical contacts

42 and 64 and thereby provides the necessary electrical connection for grounded operation of any electrical device which is plugged into the plug 16.

A latitude of modification, change and substitution is intended in the foregoing disclosure and in some instances some having a ground electrical contact disposed therein.

and a plug formed with a large diameter base and a threaded smaller diameter body adapted to threadably engage with said female screw socket,

said plug having positive and negative electrical contacts arranged on said body and a circular grounded electrical contact arranged thereon at the change in diameter existing at the juncture of said base with said body,

whereby threaded engagement of said plug with said female screw socket establishes the electrical connections of said positive, negative and ground electrical contacts.

Claims

1. A combination grounded female socket and plug comprising a socket housing having an open-ended socket compartment, a female screw socket disposed in said socket compartment having positive and negative electrical contacts, a counterbore in said open end of said socket compartment having a ground electrical contact disposed therein, and a plug formed with a large diameter base and a threaded smaller diameter body adapted to threadably engage with said female screw socket, said plug having positive and negative electrical contacts arranged on said body and a circular grounded electrical contact arranged thereon at the change in diameter existing at the juncture of said base with said body, whereby threaded engagement of said plug with said female screw socket establishes the electrical connections of said positive, negative and ground electrical contacts.