US2360444A - Electric socket - Google Patents

Description

Oct. 17, 1944. PQLLQCK ELECTRIC SOCKET Filed Dec. 10, 1942 INVENTOR. LEO POLLOCK A TTOIQNEY Patented Oct. 17, 1944 UNI-TE D STAT ES: PATENT oF 2,360,444

ELECTRIC SOCKET:

Leo Pollock, New York, N;' Y. Application Decembenll), 1942, Serial No; 468,4551

11 Claims.

This invention relates't'o electricsockets. More particularly theinvention--- pertains to electric sockets 4 which are adaptedtoreceive threaded electric plugsand the like.

The primary obj ect ofthe invention is-to-provide asocket of" the character describedwhich consists of a minimum ofsimple, easily fabricated parts, can be produced at high speed-and on. aiarge scale by'unskilled workers, is so constructed thatvery few and simple operationsare required. for. assembly, can be connected-withease in an electriecircuit'duringassembly, and

can. be producedat a lowercost than any-previously marketed socket Another object'of-the invention is to provide a socket of thewcharacter"described which will appreciably reduce the cost of fabricating and The invention accordingly consists in the fea+ tures of construction, combinations of.relements;-. and arrangement'of parts which will be exem-- plified in the construction hereinafter described, and oflwhich the scope of application will be indicated in the claims.

In the accompanying drawing, in which are shown variouscpossible embodiments of. this invention, andv wherein like numbers refer. to :like

parts throughout,.

Fig. l is a side view. of a socket, embodying my invention, with a conventional Christmas.

tree bulb. wired in a parallel circuit;

Fig. 2 is an. enlarged sectional'view thereof,

taken substantially along the line 2 in Fig. 1;.

Fig. 3 is a sectional 'view taken substantially along the line 3'3"in Fig. 2;

Fig. 4 is a sectional viewtakensubstantiallyalong the line 4'-'4' in Fig. 8;

Fig; 5 is a partially exploded view of the socket in perspective;

Fig. 6 is aperspective'view -of one of-the contact elements wired for-connection in a seriescircuit; and a Fig. 7 is a fragmentary View; similarto 'Fig1 2;

of a socket embodying a modified-form-ofmyinvention.

In general-I- accomplish the-object's of the invention by providing an-insulating housing 'i'ametrically pierced by the barrier.-

which isisplit into two halves=alongaplame pass ing through the-axis of symmetry or the housing The two halves are provided witlrma-ting recesses Off 7 difierent sizes and shapes which cooperate to form a= screw--thread for receiving a= bulb-and a :plurality I of apertures-i01 receiving and'firmly' holding simple contact elements. Aresilient*- annular element also may be provided to' facilitate electriccontactwith the screw shell'of'the bulb; this additional element being simil'arl'y held place by the mating recesses.

Referring now in detail 'tothe drawihggand more particularly toFigsz 1 5; l0 -designa-tes"an electric socket l-constr-ucted -in-'- accordancewith my invention. The socket is adapted to form= part ot a: Christmas tree lighting-outfitand' to receive: the threaded plugportion of a conventional-electric lampg -s uch-ifor' example, 'asa christmas treebulb l2; A- pair of conductor'- cables I 4; comprisingtwisted copper strand cores l6, insulating rubber sheaths l8; and braided fabric: covers 2-0; electrically -and physically connect the socket,- ina manner later described; in a para'llel Christmas tree lighti ng outfit!- The socketcom1irisesahousing 22 of-hard' rubber; Bakelite=, "orsimilar insulating 'mate'-' rial which there are contained two identical electrically conductive contact-elements 24'; 2G and an electrically conductive contact ring-281* The contact elements- '24, 26' are formed from flat stock of- "a-suitable=resilient, electrically conductive= material? like phosphor bronze; in-such" fashion as to "provide a shank 29- and" a unitary tip-30. One -l'ateral edgeof the-shank is, recessed to provide a deep- U shaped indentation 32- (Fig;

3) whichisadapted tosnugly and fully receive a conductor" cable I 4 The other lateral, edge'of" the shankis rece'ssed inalignment with the first indentation 321 The second indentation; thu sji provided, is in the form of a W, and, in efiect."

comprises symmetrically disposedtwin indentations 34*, separated by aslender barrier 36 whose" free end ispointed sothat" said barrier can" serve as a piercing'tine. The-bottoms of the twin in dentations 1 34 a are each large enough toaccom= mo'date about half the diameter-ore cable H"? but their' moutha adiacent the-tip of the? barrier; I are less than half such dlameterso-that whena-cable is: impaled-upon-the barrier and forced into the twin indentations; a part' of the cable will remain squeezed: in said mouths; The top. of the W-shaped indentation is"'as"-wide"as" the diameter of a cable so that when a cable isinserted therein it "will beso 'guided" as :to be di The lateral edges of the shanks above the deep indentations 32, 34 are recessed to provide shallow positioning notches 38 which need not be in alignment with each other.

Near the base of the shank deep transverse aligned slits 46 are cut to form two oppositely extending fingers 42. These fingers are bent to a position perpendicular to the plane of the shank and parallel to and spaced from each other. As will later be made clear, said fingers 42 are provided for use as strain relievers in the event that the socket I6 is series-connected in a Christmas tree lighting outfit.

The tips 30 of the contact elements each comprise a branch 44 which extends horizontally from the top of the shank 29, an integral wall 46 which extends vertically upwardly from the end of the branch, and a plane contact leg 48 which extends horizontally from the top of the wall 46 to which it is integrally connected. The leg 48 and branch 44 are substantially parallel and. form with the wall 46 a U-shaped tip whereof the leg 48 is longer than the branch 44. This construction permits the leg 48 to be resiliently depressed and is of particular advantage when a contact element is used as the center post of the socket in.

The contact ring 28 is formed from flat stock of a suitable resilient, electrically conductive material, like phosphor bronze, in such fashion as to provide a split annulus of flat cross-section. The annulus is deformed into a one turn helix of small pitch. The interior diameter of the helix is slightly greater than the smallest diameter of the lower inturned portion of the brass screw shell 50 at the base of the electric bulb 12.

The housing 22 includes two substantially similar halves 52, 54 which, in assembly of the socket, are adapted to be disposed in registry and abutment along a plane including the axis of symmetry of the socket.

Due to the close similarity between the two halves, only the left hand half 52 will be described and the difference between the two halves later pointed out. For convenience, elements of the left hand half 52 will be identified by unprimed reference numerals and like elements of the right hand. half 54 by like primed reference numerals.

The half 52 is substantially semi-cylindrical, the flat surface 56 thereof being adapted to abut theflat surface 56 of the other half 54. The upper part of the half 52 is provided with a central recess 58 having a flaring portion 66. Below this flared portion the recess 58 is formed into a series of sloping ridges 62 which cooperate with ridges 62' in the same zone of the half 54 to provide a female screw thread in which the screw shell 50 of the electric bulb I2 can be threaded. I p I It will be noted that because the two halves 52, 54 have their ridges 62, 62' disposed on opposite sides of the screw shell 50 that said ridges are right and left hand halves respectively of a screw thread and are not, therefore, located in identical positions in the two housing halves 52, 54. This constitutes the basic difference between said housing halves.

Below the ridged portion 62 the recess 58 communicates with asemi-cylindrical pocket 64 of sufficient diameter and height to accommodate the helical contact ring 28.

A recess 66 lies below and communicates with the pocket 64 at the periphery thereof. This recess is of proper size and shape to receive one lateral half of a contact element tip (Fig. 5) with the branch 44 resting on the base of the recess and the contact leg 48 touching a portion of the ring 28 (Fi 2).

A slot 16 extends downwardly from the center of the recess 66 and is of such dimensions as to freely accommodate one lateral half of a contact element shank between the tip 30 and the indentations 32, 34. Nibs 12 project from the sides of the slot 18 adjacent the lateral edges of the shank and are adapted to be received in the shallow shank notches 38 whereby to anchor the contact elements when the two halves of the socket are assembled.

The slot I0 terminates at a passageway 14 which runs transversely through the socket and accommodates the two conductor cables I4. Said passageway 14, adjacent the outer surface of the socket, is just of sufiicient size to receive one of the conductor cables. Beneath the slot 16, however, the passageway is enlarged, as at 16, in order to accommodate both the conductor wire l4 and the fingers 42 of a contact element 24 which, it will be remembered, are disposed perpendicular to the shank 29. Said passageway is enlarged enough to permit the base of the contact element 24 to rest thereon when the branch 44 of the contact element tip rests upon the bottom of the recess 66. Said enlarged passageway portion '16 is provided with a nib 18 adapted to project into the mouth of one of the indentations 32, 34 when the contact element is disposed in the socket half 52 and thus prevent the cables H from shifting.

The foregoing series of recesses and elements 66-18 may be duplicated on the other side of the socket halves 52, 54 to facilitate assembly of the socket by permitting the lateral contact element 24 to be disposed to either side of the center contact element 26,

Another series of recesses, slots and passageways similar tothat just described for the lateral contact element 24 is provided at the center of th socket half 52 to receive and hold the center contact element 26. Said series includes I a recess similar to the recess 66 but having its bottom surface disposed lower than the bottom surface of said recess 66. This is done in order to enable the contact leg 48 of this element to engage the low central contact 82 of the electric bulb l2 when the same is screwed into the socket 6. g A slot 84 connects the recess 85 with the conductor passageway 14. The passageway is enlarged at 86 beneath the slot 84 and to both sides of the plane thereof in order to be able to accommodate the projecting fingers 42 of a contact element regardless of which way the element is facing.

It will be noted that the said enlarged portion 86 has its bottom disposed below the bottom of the enlarged portion I6 due to the fact that the central contact element 26 is lower in the socket than the lateral contact element 24.

The slot 84 and enlarged portion passageway 86 have nibs l2 and 18 similar to those in the slot 10 and enlarged passageway portion 16. The passageway 14 intermediate the two enlarged portions 16 and 86 .is downwardly inclined (Figs,

When the two halves are assembled in regis tered relationship, the several recesses and slots .hereinabove described will cooperate to form apertures which house and firmly hold the two contact elements- 2'4, 26 and the contact ring 28-.

Suitable means are provided to hold the socket insuch assembled relationship. Such means may comprise-oppositelydisposed, apertured' ears '88 at the'plane surfaces 56; 58 of each socket half 52, 54 which are adapted to have eyelets 90 received therein when the socket is assembled.

I may prevent seepage of dirt and moisture" through the crack separating the two socket halves 52, 54 byproviding a seal comprising a groove-Garo-und the periphery of one of the halves 52 anda mating ridge R around theperipheryoftlie other half '54.

To enhance the appearance of the socket, the outer surface thereof may be indented to conform to' the inner flare Ell-immediately above the screwthreaded portion.

The socket I; having the Various elements the cable which is impaled upon a tine 36 of one contact element will be received in" the U-shaped' indentation 32 of the other contact element. The contact elements are now arranged With their shanks spaced apart a distance qual to the spacing between the slots I0, 84 in the housing halves. Next, the contact elements and conductor cables are inserted in one of the halves,'for example, the half 54, as shown at the right hand side of Fig. and the split contact ring 28 inserted in the semi-cylindrical pocket 64 of the other of said halves 52, as shown at the left hand side of Fig. 5. Finally, the two halves are brought together and the eyelets 90 passed through the apertures in the ears 88 and the ends of the eyelets spun over.

'If it is desired to place the socket in a series circuit the assembly operation is slightly varied, and is carried out as follows: A plurality of short conductor cables 92 (Fig. 6) are made of fixed length, determined by the distance the bulbs are to be spaced apart. The two ends of each short cable are placed between the fingers 42 of a contact element and said fingers clinched to anchor the short cable lengths to the elements and take up any strain imposed upon the cable 90 after the socket has been assembled. The cable is then sharply bent adjacent the end and forced into the W-shaped indentation where electrical contact with the element is made by the tine 36. A pair of elements, each from a different cable, are then inserted in one of the socket halves. If the series circuit is to be in the form of a loop, the other half of the socket may now be mounted and the eyelets 90 inserted and spun. If, however, it is desired to have the series circuit in the form of a string, like a parallel circuit, a return cable for the circuit is passed through each socket. To facilitate insertion of the return cable, the contact elements with the short cable attache-d can be placed in the socket halves with both W-shaped indentations concealed and both U-shaped indentations, which accommodate the return cable, exposed. The return cable is held in place againstaccidental disarrangement by the nib I8.

If desired, my novel socket can employ con-- ventional binding posts for making electric connections in lieu of tines 3B,- and in Fig. 7-I-'haveshown a socket 94 embodying my'invention which is adapted to make use-of this latter form of connection. Said socket differs from thesocket ID, illustrated in Figs. 1-5 only by slight varia--' tions in the contact element and socket halves. The contact elements 96, 98 have no slits 48, fin-- gers 42, tines 36, or indentations 32', 34 therein as do the elements 24, 26. Instead there is provided an annular tapped boss I09-on each contact element in which a binding post I02 isthreaded. The elements 96, 98'-are-in all otherrespects similar to the elements 24,- 26; The socket halves I04, in which the contact elements 96, 98 are received, have bottom apertures I05, I98 to pass conductor cables III], H2 attached to the binding posts. These halves have'no-nibs I8 but, save for the absence of said 'nibs and the provision of the apertures I06, I08; are similar to the socket halves 52, 54 illustrated in'Figs: 1-5. The cable passageway I4 may be leftin the" halves I04 to simplify moulding and, if required, plugged with insulating material after assembly of the socket 94.

It will thus be seen that there is provided a' device which achieves the several objects 'of this invention, and which is well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiments above set forth, it is to be'understood that all matter herein set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim" as new and desire to secure by Letters Patent:

1. A socket comprising a housing of insulating material, said housing including two halves abutted along a plane passing through the axis of symmetry of said socket, said halves having mating ridged recesses which cooperate to form a female thread and mating recesses which cooperate to form apertures, and contact elements and a contact ring received and firmly held in said apertures beneath said thread, said ring having a smaller inner diameter than that of the socket at the tips of the thread, said apertures being so arranged that one of said contact elements bears against said contact ring.

2. A socket comprising a housing of insulating material, said housing including two halves abutted along a plane passing through the axis of symmetry of said socket, said halves having mating ridged recesses which cooperate to form a female thread and mating recesses which cooperate to form apertures, and contact elements and a contact ring received and firmly held in said aperture beneath said thread, said ring having a smaller inner diameter than that of the socket at the tips of the thread, said apertures being so arranged that one of said contact elements bears against said contact ring, said ring being electrically insulated from the other of said contact elements, said other contact element being disposed diametrically and symmetrically of and below said contact ring.

3. A socket comprising a housing of insulating material, said housing including two halves abutted along a plane passing through the axis of symmetry of said socket, said halves having mating ridged recesses which cooperate to form a female thread, and mating recesses which cooperate to form apertures, and a pair of contact elements and a contact ring received and firmly held in said apertures, each of said contact elements having an offset resilient tip portion, said apertures being so arranged that the tip portion of one of said elements bears against said contact ring and the tip portion of the other of said elements is disposed centrally of and below said contact ring, said ring being electrically insulated from said other element.

4. A socket as set forth in claim 3 wherein the inner diameter of the ring is smaller than the diameter of the socket at the tips of the thread.

5. A socket as set forth in claim 3 wherein the ring is helical and has a smaller inner diameter than that of the socket at the tips of the thread.

6. A socket as set forth in claim 3 wherein the ring is helical and has a pitch differing from that of the thread.

7. A socket comprising a housing of insulating material, said housing including two halves abutted along a plan passing through the axis of symmetry of said socket, said halves having mating ridged recesses which cooperate to form a female thread, and mating recesses which cooperate to form apertures, and a pair of contact elements received and firmly held in said apertures, the lateral edges of said contact elements having shallow indentations therein and the mating recesses of said halves having nibs therein which are received in said shallow indentations to anchor said elements.

8. A socket comprising a housing of insulating material, said housing including two halves abutted along a plane passing through the axis of symmetry of said socket, said halves having mating ridged recesses which cooperate to form a female thread, and mating recesses which cooperate to form apertures, and a pair of contact elements received and firmly held in said apertures, a lateral edge of each contact element having a deep indentation therein to receive conductor cables for electrically connecting the socket in an electrical circuit, and the mating recesses of the halves having nibs which project into the mouths of said indentations to prevent the cables from shifting.

9. A socket comprising a housing of insulating material, said housing including two halves abutted along a plane passing through the axis of symmetry of said socket, said halves having mating ridged recesses which cooperate to form a female thread, and mating recesses which cooperate to form apertures, and a pair of contact elements received and firmly held in said apertures, each lateral edge of each contact element having a deep indentation therein to receive conductor cables for electrically connecting the socket in an electrical circuit, and the mating recesses of the halves having nibs which project into the mouths of said indentations to prevent the cables from shifting.

10. A socket as set forth in claim 9 wherein an indentation in one of the lateral edges of each contact element has a piercing tine in registration with the nib projecting into the mouth of the indentation.

11. A socket comprising a housing of insulating material, said housing including two halves abutted along a plane passing through the axis of symmetry of said socket, said halves having mating ridged recesses which cooperate to form a female thread, and mating recesses which cooperate to form apertures, and a .pair of contact elements received and firmly held in said apertures, each of said contact elements having a threaded aperture therein in which a binding post is received.

LEO POLLOCK.

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