US3360768A

US3360768A - Screw socket

Info

Publication number: US3360768A
Application number: US591493A
Authority: US
Inventors: Paul H Winter
Original assignee: Pass and Seymour Inc
Current assignee: Pass and Seymour Inc
Priority date: 1966-11-02
Filing date: 1966-11-02
Publication date: 1967-12-26
Anticipated expiration: 1984-12-26
Also published as: DE1589308A1

Description

Dec. 26, 1967 P. H. wlNTER 3,360,768

SCREW SOCKET Filed Nov. 2, 1966 '2 Sheeis-Sheet 1 IN VENTOI? PAUL H. WINTER A TTORNEYS P. H WINTER Dec. 26, 1967 SCREW SOCKET Filed Nov. 2, 1966 2 Sheets Sheet 2 INVENTOR PAUL H. WINTER B ZQWMW 7,1 4 ATTR/VEYS United States Patent York Filed Nov. 2, 1966, Ser. No. 591,493 7 Claims. (Cl. 339-199) This invention relates to an Edison type lamp socket and more particularly the screw threaded contact shell forming a part of the socket.

The commonly used method for making screw threaded contact shells is to take a disc of suitable metal and draw it into a cup form, then punch the necessary openings and finally roll the thread. These operations require expensive equipment which will not produce shells at a very rapid rate as compared to a conventional punch press operation.

In addition, a shell produced as indicated above has a substantial disadvantage when used with the larger type bulbs since the shell is only supported at the bottom by means of screws or rivets, the threaded portion being generally unsupported, particularly in porcelain sockets where manufacturing variations inherent in the porcelain socket bodies require clearance around the shell.

In the larger sockets, the amount of copper alloys used in the socket shell is substantial which adds appreciably to the cost of the unit. Increasing production and raw material costs have made it most desirable to provide means for reducing the cost of the socket shells.

In view of the foregoing, it is an object of this invention to provide an Edison type lamp socket having a two-piece contact shell capable of being completely produced on a punch press.

It is another object of this invention to provide a twopiece contact shell wherein only one piece is made of relatively expensive conducting metal while the other is made of a less expensive relatively non-conducting metal.

It is a further object to provide a socket having a twopiece contact shell so formed that assembly is both simple and rapid.

The above and other objects and advantages will become more apparent when considered in conjunction with the follOWing detailed description and drawings, showing by way of example one preferred embodiment of the invention.

In the drawings:

FIG. 1 is an exploded perspective view showing the twopiece contact shell and the socket housing into which they fit;

FIG. 2 is a top plan view of the socket with the twopiece contact shell positioned therein, and

FIG. 3 is a cross sectional view taken along line 33 of FIG. 2 showing further details with regard to the mounting of the two-piece contact shell in the socket housing.

As illustrated in the various figures of the drawings, the socket of this invention comprises a porcelain housing 12 of generally cylindrical configuration having a cylindrical bore 14 with an open end 16 and base 18. The base 18 has

appropriate openings

20 and 22 to receive the terminal portions of the contacttshell. The bore wall 24 is provided with a pair of

opposed locator slots

26 and 28 and a pair of

retaining grooves

30 and 32. The slots and grooves are interpositioned and generally parallel to the longitudinal axis of the bore. These slots and grooves extend up to the open end 16 of the housing. It should be noted that these slots and grooves may be slightly tapered downwardly from the open end of the housing to assist in assembly operations and facilitate pressing of the porcelain housing.

A two-piece contact shell 40 is interfitted within the housing 12. The contact shell comprises two separate

curved shell elements

42 and 44 which when assembled together form a shell unit substantially cylindrical in shape 'ice and sized to fit within the housing bore 14. Cured

shell elements

42 and 44 are of the same general height and are grooved as indicated by numerals 46 to form in effect a continuous thread when the two elements are assembled together to receive a like-threaded lamp base.

It should be noted that the two-piece contact shell 40 which is substantially cylindrical in shape may be slightly flattened on opposite sides, most advantageously between the two end portions of each curved shell element, so that the diameter between these opposite flattened portions is less than the general diameter of the contact shell. When a lamp base is threaded into such a contact shell the resulting distortion of the two

shell elements

42 and 44 will produce a generally cylindrical socket providing a substantial amount of friction between the lamp bulb threads and those of the socket shell to prevent loosening of the bulb due to vibrations and the like.

The respective confronting

edges

48 and 50 of

curved shell elements

42 and 44 have

flanges

52 and 54 and

flanges

56 and 58 respectively extending outwardly therefrom with respect to the cylinder formed by the two

shell elements

42 and 44. It should be noted that

flanges

56 and 58 in curved element 44 are spaced from one another to form a gap 60. A positioning and alignment lug 62 is formed between

flanges

52 and 54 on shell element 42. It should be noted that this lug 62 extends outwardly of and generally parallel to the edge 48 of the shell element 42 thus when the

flanges

52 and 54 are brought into confronting engagement with

flanges

56 and 58 the lug 62 will fit into gap 60 and thereby maintain alignment of the two

shell elements

42 and 44. The gap 60 and the lug 62 are properly sized to provide a close fit. Obviously, the positioning lug 62 could be located on both edges of the same shell element or one could be located on each shell element at opposite edges. The arrangement is a matter of choice as long as both edge portions of each shell element have either the gap or the positioning lug.

Flange 56 on curved shell element 44 and flange 52 on curved shell element 42 each have a

bump

57 and 53 respectively on the uppermost portion of the flange facing away from the confronting flange. These bumps are generally struck from the flange by a well known dimpling process. Thus the

bumps

53 and 57 face away from each other and provide a tight fit when the assembled

curved shell elements

42 and 44 are assembled and placed in the housing bore 14. Since the

retainer grooves

30 and 32 are tapered from top to bottom, these bumps are necessary to provide a snug fit at the upper portion of the grooves where the groove is widest.

Both

curved shell elements

42 and 44 have

locator members

66 and 68 respectively struck therefrom intermediate their ends. These locators extend outwardly from the shell elements and are sized to fit into

locator grooves

26 and 28 in the housing.

Referring to FIG. 1, it will be observed that curved shell element 44 has a terminal portion 70 extending downwardly therefrom. In addition, curved shell element 42 also has a projecting portion 72 similarly positioned. In this particular embodiment curved shell element 44 is made from a conventional current carrying metal such as a copper alloy while curved shell element 42 may be made from a relatively poor conducting material which is less expensive such as steel.

In assembling the parts of the socket to form the completed article, the

curved shell elements

42 and 44 are brought together with their

flanges

52 and 54, confiront

ing flanges

56 and 58 and positioning lug 62 fitted within gap 60. This arrangement of flanges and positioning lug is found on both confronting end portions of the

curved shell elements

42 and 44. The two curved shell elements so assembled form the substantially cylindrical socket 40 which is then introduced into the open end 16 of the housing 14 with the

locators

66 and 68 sliding down in

locator slots

28 and 26 respectively, and the flange p01: tions fitting down in retaining

grooves

30 and 32. It should be noted that the socket shell 40 is introduced into the housing bore 24 with the terminal portion 70 and projecting portion 72 extending down through

holes

20 and 22 respectively. The projecting portion 72 and terminal 70 are twisted, bent or otherwise deflected to act as retainers for the socket shell 40. Terminal 70 may be formed in the conventional manner to receive a conductor or remain straight.

Although not a part of this invention, FIGS. 2 and 3 illustrate various conventional features found in sockets. For example this socket is provided with a spring type center contact 80 including a lower terminal portion 82. The contact 80 is positioned in an elongated opening 84 having raised shoulders 36 and 88 on either side thereof. In addition the socket shell 40 is vertically positioned within the housing bore by the intermediate bearing portions 73 on projecting portion 70 and bearing portion 71 on terminal 70' both resting on the upper face 69 of the housing base 18.

It should .be noted that the assembled socket shell 40 is accurately and easily oriented within the housing bore 14 by means of the

locators

66 and 68 fitting in

locator grooves

26 and 28 and tapered

slots

30 and 32 which receive the confronting flange pairs of the

curved shell elements

42 and 44.

It will be readily apparent to those experienced in this field that the two-piece socket shell 40 wherein one piece is made from steel and the other from a better cur-rent conducting .metal represents :a substantially economy by way of raw material. Secondly, such two-piece sockets can be completely made by well known punch press methods, hence rapid increase in production rate is .achieved. Even though these economies are realized by this invention, there is no decrease in strength or serviceability as in the case of many cut-rate type sockets.

What is claimed is:

1. In an Edison type screw socket adapted to receive a threaded lamp base, a socket housing, said socket housing having a cylindrical bore with one end open, the bore wall having a pair of retaining grooves formed therein, said grooves being generally parallel to the longitudinal axis of the bore and extending up to the open end, a two-piece contact shell interfitted within the housing, said contact shell comprising two separate curved shell elements forming together a generally complete cylinder sized to fit within the housing bore, said two curved shell elements being grooved to form a thread when together, said thread being adapted to receive a likethreaded lamp base, the respective confronting edge portions of the shell elements having flange portions directed generally outwardly with respect to the cylinder formed by the two shell elements, said two shell elements being fitted together with their flange portions in confronting relation to form the cylindrical socket shell which is fitted down into the bore of the housing with the outwardly extending flange portions positioned in the retainer grooves so that the. socket shell is accurately assembled in the housing.

2. The invention as set forth in claim 1 and wherein the bore wall is also provided with a pair of locator grooves interpositioned with respect to the retainer grooves and parallel therewith, said two shell elements having locator means extending outwardly therefrom, said 10- cator means fitting in the locator grooves when the two shell elements are assembled and placed in the socket housing.

3. The invention as set forth in claim 1 and wherein at least one of the shell elements is made of a good electroconductive material and has a terminal extended therefrom.

4. In an Edison type screw socket adapted to receive a threaded lamp base, a socket housing, said socket housing having a cylindrical bore with one end open, the bore wall having a pair of opposed locator slots and a pair of retaining grooves formed therein, the slots and grooves being interpositioned and generally parallel to the longitudinal axis of the bore, said slots and grooves extending up to the open end of the housing, a two-piece contact shell interfitted within the housing, said contact shell comprising two separate curved shell elements forming together a generally complete cylinder sized to fit within the housing bore, said two curved shell elements having the same height and being grooved to form an interrupted thread adapted to receive a threaded lamp base, the respective confronting edge portions of the shell elements having flanges directed outwardly with respect to the cylinder formed by the two shell elements, positioning means interengaging the respective confronting flanges to maintain alingment between the two curved shell elements, each shell element having a locator extending outwardly therefrom intermediate the ends thereof, said two curved shell elements being fitted together with their respective flanges closely confronting each other and the positioning means maintaining alignment of the two elements to form the cylindrical shell which is fitted into the bore of the housing with the confronting flanges retained within the retainer grooves and the locators in the locator grooves to accurately position the two-piece contact shell within the housing.

5. The invention as set forth in claim 4 and wherein one of the shell elements is made of a good electroconductive material and has a terminal portion extending therefrom.

6. The invention as set forth in claim 4 and wherein the two piece contact shell is formed slightly out of round whereby when the lamp base is threaded thereinto the contact shell will slightly bind on the lamp base thread so as to prevent loosening of the lamp base due to vibration.

7. The invention as set forth in claim 4 and wherein each curved shell element has a downwardly projecting strip-like portion adapted to cooperate with the housing to retain the contact shell within the housing.

References Cited UNITED STATES PATENTS 955,438 4/1910 Russell 339-199 1,519,774 12/1924 Eberhardt 339-73 1,817,879 8/1931 De Mask 339-73 3,165,370 1/1965 Laub 339-73 MARVIN A. CHAMPION, Primary Examiner.

R. STROBEL, Assistant Examiner.

Claims

1. IN AN EDISON TYPE SCREW SOCKET ADAPTED TO RECEIVE A THREADED LAMP BASE, A SOCKET HOUSING, SAID SOCKET HOUSING HAVING A CYLINDRICAL BORE WITH ONE END OPEN, THE BORE WALL HAVING A PAIR OF RETAINING GROOVES FORMED THEREIN, SAID GROOVES BEING GENERALLY PARALLEL TO THE LONGITUDINAL AXIS OF THE BORE AND EXTENDING UP TO THE OPEN END, A TWO-PIECE CONTACT SHELL INTERFITTED WITHIN THE HOUSING, SAID CONTACT SHELL COMPRISING TWO SEPARATE CURVED SHELL ELEMENTS FORMING TOGETHER A GENERALLY COMPLETE CYLINDER SIZED TO FIT WITHIN THE HOUSING BORE, SAID TWO CURVED SHELL ELEMENTS BEING GROOVED TO FORM A THREAD WHEN TOGETHER, SAID THREAD BEING ADAPTED TO RECEIVE A LIKETHREADED LAMP BASE, THE RESPECTIVE CONFRONTING EDGE PORTIONS OF THE SHELL ELEMENTS HAVING FLANGE PORTIONS DIRECTED GENERALLY OUTWARDLY WITH RESPECT TO THE CYLINDER FORMED BY THE TWO SHELL ELEMENTS, SAID TWO SHELL ELEMENTS BEING FITTED TOGETHER WITH THEIR FLANGE PORTIONS IN CONFRONTING RELATION TO FORM THE CYLINDRICAL SOCKET SHELL WHICH IS FITTED DOWN INTO THE BORE OF THE HOUSING WITH THE OUTWARDLY EXTENDING FLANGE PORTIONS POSITIONS IN THE RETAINER GROOVES SO THAT THE SOCKET SHELL IS ACCURATELY ASSEMBLED IN THE HOUSING.