CA1039376A - Contact terminal for wedge base lamps - Google Patents

Abstract

Abstract of Disclosure A snap-in socket for wedge base lamps that avoids the requirement of a quarter turn twist for locking the socket in the panel. Contact members are adaptable to be inserted from either end of the socket. One modification of the contact member utilizes a snap-on hood for providing one electrical return path through a chassis thereby requiring only a single wire to the socket. The contact members further feature wire guide means thereon which function to straighten any bent filament wires on the lamp bulb when the bulb is inserted into the socket as-sembly.

Description

- 10393~6 This invention relates to a snap-in panel mounted lamp socket for wedge base lamps and specifically to improved contact terminals therefor. This application is a divisional application of Application Serial No. 231,330, filed July 14, 1975.
Prior Art .
Prior art lamp sockets for wedge base lamps are inserted into a panel aperture having at least one slot adjacent thereto and then twisted to move a pair opposing cam locks from out of the slot and over the wall of the aperture. This operation involves fabricating a special non-round configuration on the panel aper-ture. If the socket is assembled to the panel on an assembly line operation, the act of twisting the socket is often omitted.
Additionally, in previous sockets it was necessary to extend the socket housing to provide support for the lamp or to provide additional structure as a lamp holding sleeve inasmuch as the socket contacts did not grip the lamp with sufficient force.
Oftentimes the filament wires on the wedge base of the lamp are bent resulting in improper electrical contact with the contact members in the socket and inoperative or faulty lamp operation.
The present invention relates to a wedge-shaped lamp socket contact member for attachment to the end of a wire com-prising: an elongated member having a contact end portion and ~ -wire attachment end portion, the member having a bottom web ex-tending along both portions, the contact end portion comprising interconnecting two spaced apart parallel side members connected to the web and longitudinally extending from one end of the web to a point intermediate the ends. A wing member extends lon-gitudinally from each of the side members substantially parallel to and displaced from the bottom web with a free end of the wing member longitudinally extending beyond the side meJ~er. A pro- -tuberance extends transversely across each of the wing~ and is _ 1,_ ~ , jc/ ,~
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10393~76 displaced from the free end. A first resilient cantileverly supported tab angularly extends from the bottom web at a point intermediate the ends of contact end portion and in a direction opposite to the side members, the free end of the tab extending toward the wire end portion of the elongated member. A second resilient tab is spaced rrom the first rèsilient tab in a direc-tion toward the wire end of the elongated member. The second tab cantileverly supports and angularly extends in a direction toward the plane formed by the wing members, the free end thereof exten-ding toward the contact end of the elongated member. The firstand second tab members cooperate for retaining the contact member in a wedge base lamp socket.
The features and advantages of the socket contact member will become apparent from the following detailed description, drawings and claims of a socket contact member for wedge base lamps.
Description of the Drawings In the drawings:
Fig. 1 is an elevation view of the snap-in lamp socket assembly including a lamp;
Fig. 2 is a left-hand end view of the snap-in lamp socket of Fig. 1 with the lamp and contacts removed; -~
Fig. 3 is a fragmentary sectional view taken along line 3-3 of Fig. 2 and also illustrating the socket snapped jc/ ';,~, .,, ~
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10393'76 into a panel, Fig. 4 is a right-hand vie~7 of the snap-in lamp sock.et of Fig. 1 with the lamp and contacts removed;
Fig. 5 is a sectional view taken along line 5-5 of Fig. 4 with the contacts in the section and the lamp shown in elevation and illustratinlg the electrical connection in the socket and the securing of the contact members in the socket;
Fig. 6 is an elevation view of the snap-in lamp socket of Fig. 1 partly in section and illustrating a lam~ cover and a - -modification of one of the contacts; -Fig. 7 is an elevation view of one form of contact for the snap-in lamp socket assembly of Fig. 1, ,~
Fig. 8 is a sectional view taken along line 8-8 of -Fig. 7;

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10393~76 Fig. 9 is an elevation view of one modiflcation of the contact of Fig. 7 that is illustrated in Fig. 6;
Fig. 10 i~ an elevation view of another modification of the contact of Fig. 7;
Fig. 11 is an elevation view of the contact member of Fig. 9 provided with a filament wire guide and straightening structure in accordance with another aspect of the invention;
Fig. 12 is an end view taken in the direction 12-12 of Fi8. 11;
Fig. 13 is a fragmentary view of a wedge-type bulb received between a pair of cooperating contact members provided with the wire guide and straightening structure of the invention.
Fig. 14 i9 a plan view taken in the direction 14-14 of Fi8. 13;
Fig. 14A is a view similar to Fig. 14 showing the contact member of Fig. 14 received in position on the wedge based lamp bulb and the ~traightening action of the wire guide and straightening structure of the contact members of Figs.
11-15; ant Fig. 15 is a sectional end view taken in the direction 15-15 of Fig. 13;
Detailed Description Referring to the Figs. by the characters of reference, ~--there i8 illustrated in Fig. 1 an elevation of a snap-in socket ;' assembly 20 for a wedge base bulb or lamp 22. The wedge base - -lamp, which is well known and manufactured by several lamp ~~
manufactures such a~ General Electric and Westinghouse, has -a bulbular evacuated chamber section 24 fused to a wedge-type base 26. The base configuration includes a raised cylindrical centrally located vent tube portion 28 bounded by laterally extending side wings 30 of substantially flat rectangular cross section, as shown in ~lg. lS. Both ends of 32 of the lamp r~

,: ,~ ' ' ~ '' " '! ' ' ' ~ ' ' ' ' ' ~ 10393~i filament extend through and exit out of the bottom end of the side wings and are formed on diagonally opposite surfaces of the wings in such a manner that on either side of the central cylindrical vent tube portion there is only one end of the fil-ament wires, which is bent or looped back upon itself, as indi-cated in Fig. 14, with its end reentrant in and sealed in the wedge base.
Extending across each side of the side wings trans-versely to the normal axis of the lamp is a concave detent trough 34. The troughs are in line interrupted only by the central cylindrical portion 28 of the base. The filament extension wires overlie and extend beyond the detent trough 34, as shown in Figs. 14 and 14A in which the looped filament wire of Fig.
14 is indicated as bent or misaligned and is straightened by the contact member wire guide and straightening structure as depicted in Fig. 14A. It is through a corresponding, mirror image detent 36 on the contacts 38-40 that the lamp is held in a socket and electrical contact is made.
The socket 42 is an elongated tubular housing having an elongated rib 44, which is shown as extending from sub~tan-tially near one end of the housing to the other end. A rim 46 girds the housing at the other end from which at least two opposed cantileverly supported side panels 48 extend in an axial direction with respect to the housing~ A protuberance or dimple 50 is positioned along the outside surface of each of the side panels and is spaced a predetermined distance from the rim 46. A pair of contact members 38-40 are positioned within the housing 42 on either side of the rib 44 forming a lamp receiving throat at the free end of the side panels 48. ~ -The elongated tubular housing 42 in the preferred embodiment, is fabricated from an electrically non-conductive material, ~xcept for the slight molding draft angles, which rw/,c , 1039~76 are necessary for one form of manufacture, the housing is cylindrical in shape having a right circular cross-~ection.
The inside surface 52 of the housing deflnes a cavity which is divided into two ~ections 53 and 54 by means of the elon-gated rib 44. Into each section there is located a portion of the contact member.
Along the inside surface 52 or the walls of the cavity there i9 a longitudinally flat surface 56 opposite to and paral-lel with the broadside surfaces 58 of the rib. As will herein-after be shown, each of these flat surfaces 56 and the opposed brOadside surfaces 58 or the rib 44 cooperate with the contact members 38-40 to maintain the contact members out of electrical contact with each other except through the filament of the bulb.
A rim 46 having a rectangular cross-section girds or encircles the housing 42 at the other end. Around the inside surface 52 of the cavity, the rim 46 forms a shoulder 60 at the end of the flat surface 56.
At least two spaced-apart and opposed side panels 48 ,,'A
- are cantileverly supported and extend in an axial direction away from the other end or rim end of the housing 42. In the --preferred embodiment, these panels 48 are C-shaped in cr~5s-section wherein each C-shaped configuration forms a pair of Jaws. The orientation of the side panels 48 is such that if the plane of rib wa~ extended, it would bisect each C-shaped ~ -panel or pair of iaws putting one ~aw of each pair on each side of the rib. The function of each ~aw of the C-shaped panel 48 i8 to retain and to maintain the contact members in electrical contact with the lamp.
The protuberances 50 along the outer surface of each C-shaped ~ide panel 48 cooperate with the rim 46 for securing the ~ocket within an aperture 61 in a mounting panel 62, as illu~trated in PigR. 1 and 3. In this application, the pre-r~
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10393~6 determined distance between the protuberance 50 and the rim 46 is equal to the panel thickness. The socket 42 is inserted in an aperture 61 having a size equal to the size of the hou~ing and the resiliency of the side panels 48 allows the wall of the aperture 61 to bend the panels toward each other. As the protuberance 50 has passed through the side panel, the latter returns to its normal position, trapping and securing the socket in the aperture 61 with the sides of the panel 62 held between the rim 46 and the protuberance 50.
Another function of the protuberance 50 is illustrated in Fig. 6 wherein the socket assembly 20 of Fig. l has a metal-lic hood member 64 ~napped on over the bulb 22. The hood member 64 has an encircling channel 66 conforming to the size of the protuberance 50. When the hood is positioned over the socket 42, the leading edge 68 of the hood rides over the protuberance 50, causing the side panels 48 to resiliently bend until the protuberance snaps into the channel 66. The hood 64 is then secured to the housing 42.
A pair of contact members 38-40 complete the socket assembly 20 aq illustrated in Fig. l. Depending upon the ap-plication and electrical requirements, the contact members may -both have wire leads attached thereto as shown in Fig. l.
This contact 38 embodiment is illustrated in greater detail in -Fig. 7. However, when the socket is supported by means of a ~-~
chassis strap, such as illustrated in Fig. 6, and wherein the chassis provides one electrical connection, such as ground, a contact member 39 as illustrated in Fig. 9 may be used as one of the contact members.
The contact members 38-40 are each located in one section 53 or 54 of the cavity and they extend between the opposed ~ide panels 48. The contact members 38-40 are divided into a lamp receiving end and an opposite end where in the one rwl~ ~ 7 ~

10393q6 modification 38 and 40 the circuit wires 70 are attached as by crimping in the wire clinshing ferrule-shaped end of that form of contact member. The lamp receiving end is formed into a channel shaped member 72 having a pair of wings 74 ex-tending laterally outwardly from the top surface of the side walls 76 of the channel. The wings 74 are substantially par-allel to the base or bottom web 78 of the channel and extend longitudinally beyond the end of thè channel.' Positioned on each wing and extending beyond the end of the channel is a overhanging and resilient protuberance or detent 36 for mesh-in,g with t~he in-line troughs 34 on the wedge base 26 of the lamp 22. The detents 36 are in-line and extend normal to the ' -longitudinal length of the contact members 38-40.
As indicated above, the contact members are positioned within the housing 42, one on each side of the rib 44, and they extend longitudinally between both pair,of jaws 48. The ~ -wings 74 of each contact member cooperate with the opposed wings of the opposite contact member to form a lamp or bulb receiving throat. When the wedge base 26 portion of the lamp , i~ inserted between the wings, the jaws resiliently deform outwardly in a direction of opening to allow the base 26 of the lamp 22 to enter. When the troughs 34 on the lamp corres- , pond in position to the detents 36 on the wings 74, the jaws close to copressively mesh the protuberances with the troughs. '-Once the lamp 22 is in place, the jaws close, applying suffi-cient force on the wings 74 to hold the lamp without any exter- -nal holding means. The side panels in the preferred embodiment do not extend to bear or lie in close proximity to the chamber section 24 of the lamp for holding the lamp in the socket. The only holding of the lamp is by the contact members 38-40 co- ' ' operating with the jaws 48. ' , r~J/,' - 8 -. .

1039~76 In the preferred socket embodiment, there are positiooed two additional side panels 80 interposed in the space between each of the C-shaped jaw side panels. These panels 80 are also cantileverly supported from the rim 46 and extend longitudinally the same length as the C-shaped panels 48. Positioned on the outer surface of each of these two panels is a flat groove or indented surface 82. The groove extends from the end of the panels toward the rim 46 on the housing. The groove cooperates with the modified contact member 38 illustrated in Fig. 9 and the metallic, electrically conducting hood 64 or a chassis strap to locate and to provide a second electrical connection to the socket, as illustrated in Fig. 6.
The contact member 36 illustrated in Fig. 9 has a hook member 84 extending from the bottom web 78 in the direc-tion of the lamp receiving end of the wings 74. This hook mem-ber 84 is positioned in the groove 82 of the side panels 80 to make electrical contact with the hood 64 as illustrated in Fig. 6 through a chassis strap 86 to the source of electrical power. As a modification, the end of the hook member could -be extended to lie along the housing as far as the rim. In this manner, the contact would make an electrical connection to the panel through the aperture wall.
The opposite end of the contact member, illustrated in Figs. 7, 8, and 10, i.e., the end opposite the lamp receiv-ing end, has a ferrule or wire receiving means formed thereon.
In this embodiment, the bottom web 78 of the channel 72 is ex~
tended and two spaced apart pairs of crimp members 88 and 89 - -are formed out of the side walls of the channel. The first ~ - -pair of members 88 nearest the wing members crimp the conduct- ~-ors of the attached wire while the second pair of members 89 crimp the insulation. The end 90 of the bottom web beyond the second pair of members is formed at a downward depending angle r~rl -forming a tab extending in a direction opposite to the wing members 74.
Along the top surface of each of the wings a resilient tab 92 i8 formed extending away from the surface. The tabs are cantileverly supported with the free end extending toward the opposite or wire receiving ferrule end of the contact members 38-40.
~hese three tabs, one on each wing 92 and the tab 90 -at the wire receiving end of the contact member, respectively cooperate with the broadside surface 58 of the rib 44 and the opposed flat surface 56 on the inside of the housing 42 for holding each contact member in a spaced relationship to the opposite contact member. Since the tabs 90 and 92 extend away from the contact member in opposite directions, they also func-tion to keep the contact members snug in the socket and free from relative movement within the socket. The end of the rib 44 near the rim 46 constitutes a stop member 94, which extends lnto each section defined by the rib 44, as shown in Figs. 3 and 5. A second stop member is located on the inner surface ~ ~ -20 - 52 of the housing at the rim end and may be the shoulder 60 formed at the end of the flat surface 56 by the rim 46. The surface 96 of the first stop member 94 nearest the wire receiv-ing end of the contact members 38, 40 and the surface 60 of the second stop member nearest the lamp receiving throat cooperate wlth a pair of spaced tabs 98-99 (Figs. 7, 8 and 9) on the bottom web 78 of the contact members 38 and 39 to securely -hold the contact members in the socket from forces applied externzl to the socket. - i-In Pigs. 7 and 9 one of the above mentioned spaced tab members 98 is formed at right angles to the bottom web 78 and the other tab member 99 is cantileverly extended from the ;~

bottom web in a direction opposite to the extent of the first :

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~039376 tab member. The free end of the cantileverly supported member 99 and the bearing surface of the normal tab 98 are spaced apart a distance substantially equal to the longitudinal length between the surfaces 96 and 60 of the two stop members in the housing interior. The direction of insertion of the contact -:
member into the socket determines the relative positioning of the tabs with respect to the lamp receiving ends of contact.
The cantileverly extending tab 99 ls inserted first into the -socket, and the normal tab 98 limits the depth of insertion of the contact member. The tab configuration of Fig. 7 is used when the contact member ls inserted from the wire receiving end of the socket. The configuration illustrated in Fig. 9 is used when the contact member is inserted from the lamp receiving end of the socket. Once the contact member is inserted and each tab 98 and 99 is bearing or abutting against its respective stop surfaces 96 and 60, the contact member cannot be removed without ~-damaging the socket, breaking a tab or unless the cantileverly supported tab 99 is depressed toward the web surface.
If the contact member has a wire crimped to the end thereof as illustrated in Fig. 5, the lamp receiving end of the contact i8 inserted first into the wire receiving end of the hou~ing. The contact member i5 moved toward and between the ~aws on the side panels. The normally extending tab 98 locates on the surface 96 of the first stop member 94, and the free end of the cantileverly extending tab 99 locates on the shoulder ;~ ' surface 60 constituting the second stop member.
Referring to Fig. 10 there is illustrated a modifica-tion of the contact member of Fig. 7 wherein both tabs 100 and 101 from the bottom web 78 are cantileverly supported and extend away from the web in opposite directions. This construction allows the contact to be inserted into the socket from either end and the tab which is inserted first, the leading tab, is rw/,~

1039~7~
resiliently deformed by either the first stop member 94 or the flat surface 56. Again, the spacing between the free ends of the tabs is substantially equal to the longitudinal distance be-tween the two surfaces 94 and 60 of the stop members.
For ease of manufacture, the housing 42, the side panels 58 and 80 including the ~aws, the rib 44, the rim 46 and stop member 94 may be molded as a unitary structure. When this is so, the material in each section has the same electrical and temperature characteristics. In a similar manner, all of the several features of the contact members 38-40 may be formed from a single piece of material. It has been found that three-quarter hard brass combines th~e resilient characterlstics re-quired by the tabs along with the electrical conductivity char-acteristics required of the contact members.
Fig. 11 illustrates a modification of the contact member 39 of Fig. 9 to which has been added a filament wire guide and straightening structure in the form of a raised rib 106 on the detent 34 thereof. The rib 106 is struck out from the inner curved surface of one of the detents 36 of a contact member,asby swaging orlrolling~ to form a raised, longitudinally extending curvilinear ridge ad~acent the inwardly facing side thereof as shown in Fig. 12. The ridge 106 thus locates between the vent tube of the bulb base and the exit of a filament wire on the wedge base and serves to guide the filament wire, straight-ening it in the event the wire should be bent as indicated in ;`
~ig. 14, as the bulb base is inserted in the aforementioned throat formed between an opposed pair of contact members as shown in ~igs. 13 and 14A. !' There has thus been shown and described a snap-in --socket for wedge base lamps with contact members therefor which permit contact insertion from ei~her end of the socket as re-quired and further featuring filament wire guide and straight-ening structure on the contact members.

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Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A wedge-shaped lamp socket contact member for attachment to the end of a wire comprising:
an elongated member having a contact end portion and wire attachment end portion, said member having a bottom web extending along both portions, said contact end portion com-prising interconnecting two spaced apart parallel side members connected to said web and longitudinally extending from one end of said web to a point intermediate the ends, a wing member extending longitudinally from each of said side members and substantially parallel to and displaced from said bottom web, a free end of said wing member longitu-dinally extending beyond said side member, a protuberance transversely extending across each of said wings and displaced from said free end, a first resilient cantileverly supported tab angularly extending from said bottom web at a point intermediate the ends of contact end portion and in a direction opposite to said side members, the free end of said tab extending toward the wire end portion of said elongated member, and a second resilient tab spaced from said first resilient tab in a direction toward said wire end of said elongated member, said second tab cantileverly supported and angularly extending in a direction toward the plane formed by said wing members, the free end thereof extending toward the contact end of said elon-gated member, said first and second tab members cooperating for retaining said contact member in a wedge base lamp socket.

2. A contact according to claim 1 additionally in-cluding a third resilient tab cantileverly supported from each of said wing members, the free end thereof extending in the direction away from said bottom web, and a fourth tab member extending outwardly and away from said wire end of said elongated member in a direction opposite to said third tab member, said fourth tab member cooperating with said third tab member for compressively holding said con-tact in the socket.

3. A lamp socket contact member for a wedge base lamp bulb of the type having a bulbular filament enclosing portion and a flattened base having a centrally located sealed vent tube with a pair of oppositely laterally extending wings therefrom, each of said wings having a pair of in-line trough-like inden-tations formed in and extending transversely on each face thereof and a bulb filament wire extending internally in one direction therethrough and externally in the opposite direction and over-lying a trough-like indentation on one face of a different one of the wings of the wedge base, said contact member having a generally channel-shaped, longitudinally extending portion with spaced sidewalls joined by a substantially flat web portion, each of said sidewalls having a wing extending laterally outwardly therefrom substantially parallel to said web portion and longitudinally of said contact member and past the end of the web portion thereof, each of said wings of said contact member having a curved portion forming a detent protuberance thereon adapted to engage in a trough-like indentation on the wedge base of a bulb, one of said protuberances having a guide means formed thereon for guiding and straightening of a bent external filament wire on the base of said bulb when the bulb base is inserted between an opposed pair of such contact members in a lamp socket.

4, A lamp socket contact member in accordance with

claim 3 above wherein said wire guide straightening means is positioned on a wing adjacent a sidewall of said contact member to locate between the vent tube of the bulb base and the exit of a filament wire therefrom.