CANTILEVERED REDUNDANT TERMINAL

Abstract: A secondary electrical contact means in a snap-in termin­ al, cantilevered from the terminal such that contact is urged with misaligned filament wires of a wedge base bulb.

Description: The present invention relates to a socket assembly comprising a snap-in lamp terminal in a socket housing for receiving, locating and positioning a wedge-base bulb having a pair of filament extension wires positioned on sides of the wedge base, a pair of troughs extending transverse to the wedge base, the wedge base further having a centrally located cylindrical vent tube and a bulbular evacuated chamber both in the same longitudinal axis, the vent tube bounded by laterally extending side wings of the wedge base, the snap-in terminal comprising: a lamp receiving portion and a conduit receiving portion; the conduit receiving portion including wire retention means; the lamp receiving portion having a terminal base and terminal side portions; cantilevered contact are projecting into the interior of the lamp receiving portion; the contact arms including spring contact members for communication with the detent troughs of the bulb and filament wires of the bulb; a wire guide means projecting into the interior of the lamp receiving portion such that a wiping action will occur when the wedge-base bulb is inserted into the terminal thereby straightening any skewed portion of the filament wires. A snap-in lamp terminal of this type has become known from US-A-4 181 390. In this design the wire guide means provides for better filament wire positioning. To this end the wire guide means protrudes out toward the center of the terminal and wipes near the surface of the vent tube. This wiping action was designed to realign a filament wire skewed onto the middle of the wedge-base extending across the body of the vent tube. Realignment occurs when the wire guide interferes with the filament wire and pushes it back to its proper mating position. Alignment of skewed filament wires protruding toward the exterior edge of the side wing occurs by interference with the terminal base. This interference urges the skewed filament wire back to its proper mating position. The wire guide in some cases cannot reach extremely skewed filament wires and the terminal base cannot align skewed filament wires to the extreme outer edge of the side wing. Because of these extremely skewed filament wires, a wedge-base bulb might light intermittently or possibly not at all, and a costly manual realignment of the filament wires becomes necessary. It is, therefore an object of the invention to provide a socket assembly comprising a snap-in lamp terminal for wedge-base bulbs with improvements in the wire guide design to urge proper alignment of the filament wires of the bulb which may be skewed onto the central vent tube, and to urge proper electrical contact should the terminal base or the improved wire guide fail to realign the filament wire to its proper mating position. To this end a snap-in lamp terminal of the above identified type, according to the present invention, is characterized in that said terminal side portions of the lamp receiving portion are shaped as continuous terminal sides so that the clamp receiving portion is of a generally channelized shape; the cantilevered contact arms extend from the terminal sides via folded tabs; the terminal sides have curved bulb guides at the lamp receiving end to communicate with the wedge-base bulb; the wire guide means projects into the generally channelized lamp receiving portion from one of the terminal sides adjacent said curved bulb guides such that the wire guide means wipes along the vent tube of the bulb; and redundant terminal means comprising a cantilevered redundant terminal is formed from a terminal side into the interior of the generally channelized lamp receiving portion of the snap-in terminal and affixed to the side via a folded tab, the cantilevered redundant terminal being directed toward the contact arm opposite said tab and designed for contact with the filament wires of the wedge-base bulb. DE-A-2 535 879 discloses a snap-in lamp terminal of a different type wherein a pair of U-shaped contact arms are arranged in axially spaced positions opposite to a third contact arm to improve mechanical and electrical connection of the lamp terminal and bulb. The subject invention urges better electrical contact upon installation by providing a wire guide which wipes onto and not near the surface of the vent tube urging better alignment for even extremely skewed filament wires onto the vent tube. Furthermore the subject invention provides a redundant contact terminal means whereby a skewed filament wire, not properly aligned by the improved wire guide or the terminal base, will still be urged to make proper electrical contact by providing a second contact surface in the interior of the terminal channel. Other objects, features and advantages of the present invention will become more fully apparent from the following detailed description of the invention, the appended claims and in the accompanying drawings in which: Fig. 1 is a perspective view of a typical wedge-base bulb or lamp which is inserted into the socket-terminal assembly described herein; Fig. 2 is a perspective-exploded view showing the wedge-base bulb, the socket housing and snap-in terminal; Fig. 3 is a sectional view through the housing shown in Fig. 2 with the snap-in terminal shown in place and the wedge-base bulb in position to be inserted; Fig. 4 is a sectional view through Fig. 3 illustrating the wedge-base bulb in position, and in communication with the snap-in terminal, the wire guide means, and redundant terminal means; Fig. 5 is a sectional view illustrating the bulb retention features of the snap-in terminal as well as the cantilevered redundant terminal in communication with the filament wires; Fig. 6 is a sectional end view illustrating the wiping action of the wire guide Fig. 7 is a plan view of the snap-in terminal with cantilever redundant terminal means; Fig. 8 is a side view of the subject terminal; Fig. 9 is an end view of the subject terminal; Fig. 10 is a perspective view of a snap-in terminal with cantilever redundant terminal means; Referring to Fig. 1, a wedge-base bulb typical of the bulbs or lamp utilized in the subject invention in an automotive environment is illustrated along with its filament wires. The wedge-base bulb 32 consists of a bulbular evacuated chamber 34, a wedge-base 36 and a vent tube 38. The vent tube 38 is a cylindrical shape and centrally located on wedge-base 36 in the longitudinal axis of bulbular evacuated chamber 34. The centrally located cylindrically shaped vent tube 38 separates two side wings 40 of the wedge base. The side wings 40 encapsulate the filament wires 42 and also have a concave detent trough 44. The troughs 44 are perpendicular to the vent tube 38. The filament wires 42 extend out from the end of the side wings and are bent along the face of the side wings in the longitudinal axis of the bulbular evacuated chamber 34. The filament wires are bent along the flat surface 46 of the side wings. The flat surface 46 is opposite the side wing surface carrying the concave detent trough 44. Referring now to Fig. 2, the wedge-base bulb 32 is shown in perspective with socket 50 and snap-in terminal 70. Socket 50 is generally of tubular construction and shape and comprises a bulb housing section 54 and a terminal axis chamber 56. Also included in this particular socket embodiment is rim 52 which is designed as a stop for panel mounted bulbs. The bulb housing 54 is of cylindrical shape. The terminal access chamber 56 is also generally cylindrically shaped and is designed to accept a pair of terminals 70. Terminal guides 64, shown in Fig. 3, are slotted through terminal access chamber 56 and bulb housing 54 terminating in end stop 62. The Snap-in terminal 70 is inserted into the terminal access chamber 56 through terminal guide ports 66. The terminal guide ports 66 are separated by terminal guide center posts 68. Also provided in tubular socket 50 are wedge clamps 58. The purpose of these wedge clamps is to communicate with the snap-in terminal 70 and lock it in place. This occurs via wedge member 60 shown in Fig. 3 which is attached to the interior of wedge clamp 58. Wedge clamp 58 is cantilevered onto the housing assembly such that the portion at the end of bulb housing 54 when pulled will move outboard of housing 50 being hinged on terminal access chamber 56 thereby pulling wedge member 60 out of communication with terminal 70 and releasing terminal 70 from the socket 50. The wedge 60 communicates with the wedge receiving slot 82, shown in Fig. 10, provided in snap-in terminal 70. Referring now to Fig. 10, as well as Fig. 2, the snap-in terminal 70 comprises a lamp receiving portion 72 and a conduit receiving portion 74. The conduit receiving portion 74 communicates with conduit 76 via crimped wire retention flanges 78 and provides sufficient physical and electrical connection to snap-in terminal 70. The lamp receiving portion 72 is generally a channelized part comprising a terminal base 80 and terminal sides 84. The terminal base 80 provides the previously mentioned wedge receiving slot 82 and forms the base from which terminal sides 84 are formed. Cantilevered from terminal sides 84 on the interior side of the channel are contact arms 86 and 88. The contact arms 86 and 88 are formed by a folding action resulting in tabs 89. On each contact arm 86 and 88 are concave spring contacts 90. The purpose of the contacts 90 are to communicate with the filament wires 42 or the concave detent troughs 44. Formed from the bulb end of one of the terminal sides 84 is wire guide means 92. The purpose of the wire guide means is to communicate with filament wires 42 which may be skewed along vent tube 38. The communication between the wire guide means 92 and the filament wires 42 is the result of the wiping action of the wire guide means 92 along the vent tube 38. At the end of this wiping action, the filament wire 42, if skewed along the vent tube 38, should now be in proper mounting position in the longitudinal axis of bulbular evacuated chamber 34. The interaction between the filament wire 42 as supported by side wing 40 and wire guide means 92 results in the deformation of wire guide means 92. Also provided at the bulb end of the terminal sides 84 are bulb guides 94 which are rounded tabs to guide the side wings 40 into communication with the contact arms 86 and 88. The contact arms 86 and 88 are cantilevered into the interior of the channelized portion of the snap-in terminal 72 to provide a spring biased retention force on the wedge-base bulb 32 by engaging the concave detent troughs 44 via concave spring contacts 90 and by engaging filament wires 42 with concave spring contacts 90. Alignment of skewed filament wires 42 protruding toward the exterior edge of the side wing 40 are urged toward proper alignment through interference with the terminal base 80. Also shown in Figs. 2 and 10 is the preferred embodiment of the redundant terminal means which is designed to make electrical contact with filament wires 42 which are skewed onto the sides of side wings 40 or out of reach of the wire guide 92 and not aligned by interference with base 80. The redundant terminal means illustrated in Figs. 2 and 10 is shown as cantilevered redundant terminal 96. This cantilevered redundant terminal 96 is formed from the folded tab 89 on the contact arm 86 which is designed to communicate with concave detent trough 44. The cantilevered redundant terminal 96 is positioned in the interior of the generally channelized lamp receiving portion 72 and is directed toward contact arm 88 which is designed to communicate with filament wire 42. Fig. 4 is a sectional view through Fig. 3 illustrating the wedge-base bulb in position, and in communication with the snap-in terminal, the wire guide means, and redundant terminal means. Fig. 5 is a sectional view illustrating the bulb retention features of the snap-in terminal as well as the cantilevered redundant terminal in communication with the filament wires. Fig. 6 is a sectional end view illustrating the wiping action of the wire guide means. Fig. 7 is a plan view of the snap-in terminal with cantilever redundant terminal means. Fig. 8 is a side view of the subject terminal. Fig. 9 is an end view of the subject terminal.

Claims: A socket assembly comprising a snap-in lamp terminal (70) in a socket housing (50) for receiving, locating and positioning a wedge-base bulb (32) having a pair of filament extension wires (42) positioned on sides of the wedge base (36), a pair of troughs (44) extending transverse to the wedge base (36), the wedge base further having a centrally located cylindrical vent tube (38) and a bulbular evacuated chamber (34) both in the same longitudinal axis, the vent tube (38) bounded by laterally extending side wings (40) of the wedge base (36), the snap-in terminal (70) comprising: a lamp receiving portion (72) and a conduit receiving portion (74); the conduit receiving portion (74) including wire retention means; the lamp receiving portion (72) having a terminal base (80) and terminal side portions (84); cantilevered contact arms (86, 88) projecting into the interior of the lamp receiving portion (72); the contact arms (86, 88) including spring contact members (90) for communication with the detent troughs (44) of the bulb and filament wires (42) of the bulb (32); a wire guide means (92) projecting into the interior of the lamp receiving portion (72) such that a wiping action will occur when the wedge-base bulb (32) is inserted into the terminal (70) thereby straightening any skewed portion of the filament wires (42), characterized in that said terminal side portions of the lamp receiving portion (72) are shaped as continuous terminal sides (84) so that the lamp receiving portion (72) is of a generally channelized shape; the cantilevered contact arms (86, 88) extend from the terminal sides via folded tabs (89); the terminal sides (84) have curved bulb guides (94) at the lamp receiving end to communicate with the wedge-base bulb (32); the wire guide means (92) projects into the generally channelized lamp receiving portion (72) from one of the terminal sides (84) adjacent said curved bulb guides (94) such that the wire guide means (92) wipes along the vent tube (38) of the bulb (32); redundant terminal means comprising a cantilevered redundant terminal (96) formed from a terminal side (84) into the interior of the generally channelized lamp receiving portion (72) of the snap-in terminal (70) and affixed to the side via a folded tab (89), the cantilevered redundant terminal (96) being directed toward the contact arm (88) opposite said tab (89) and designed for contact with the filament wires (42) of the wedge-base bulb. The socket assembly of claim 1 where the terminal base (80) further comprises a wedge receiving slot (82) for engagement with the socket housing. The socket assembly of claim 1 or 2, characterized by a generally tubular shaped socket (50) for receiving the wedge-base bulb (32) and the snap-in terminal (70); the socket (50) comprising a bulb housing (54) and a terminal access chamber (56) for a pair of snap-in terminals (70); the bulb housing (54) being of generally cylindrical shape and having a pair of end stops (62) which define a bulb entrance to the housing; a pair of terminal guides (64) slotted through the terminal access chamber (56) and bulb housing (54) terminating with the end stops (62) in the bulb housing (54); terminal guide ports (66) providing access to the terminal guides (64) for the snap-in terminals (70); and the bulb housing (54) further comprising wedge clamps (58) hinged from the socket housing and providing a wedge for communication with the terminal base wedge receiving slot (82) thereby entrapping the snap-in terminal (70).

Inventors: DURAND, REMIE P.
Applicants: CHRYSLER CORPORATION
Application year: 1986
Main classification: H01R33
IPC codes: H01R33