US3581081A

US3581081A - Automotive license lamp assembly

Info

Publication number: US3581081A
Application number: US849079A
Authority: US
Inventors: Lawrence E Rieth
Original assignee: Stewart Warner Corp
Current assignee: Stewart Warner Corp
Priority date: 1969-08-11
Filing date: 1969-08-11
Publication date: 1971-05-25
Anticipated expiration: 1988-05-25

Abstract

A lamp is removably carried by an open J-slot socket which is concentrically positioned within a cylindrical bushing. The socket is positively locked in place and resiliently sealed against the bushing by a unitary rubber boot which covers the rearward portion of the socket and is compressed between the socket and the bushing.

Description

United States Patent [72] lnventor Lawrence E. Rieth [56] References Cited Sgnngfeld, 111. UNITED STATES PATENTS [2H P 8 2,440,455 8/1948 Bowman 240/83 22 F1led Aug. 11,1969

I 2,489,715 11/1949 Mark. Jr. et 211.. 277/212 [45 1 Pmmed May 2 860 233 1 1/1958 Johnson Jr 240/90x 7 .1 l 3] Awgn :3; r Cmpmm 2,903,570 9/1959 Worden 240/s.3x g 3,413,024 11/1968 Farquhar 277/237X Primary Examiner-Louis R. Prince Assistant Examiner-Daniel M. Yasich Attorneys-Augustus G. Douvas, William J Newman and Norton Lesser [54] AUTOMOTIVE LICENSE LAMP ASSEMBLY Claims 4 Drawmg ABSTRACT: A lamp is removably carried by an open .l-slot [52] US. Cl .1 240/83, socket which is concentrically positioned within a cylindrical 277/212 bushing. The socket is positively locked in place and [51] Int. Cl B60q 1/30 resiliently sealed against the bushing by a unitary rubber boot Field of Search 240/83, which covers the rearward portion of the socket and is compressed between the socket and the bushing.

PATENTEDHAYZSIBYI 8.581.081

,1 I6 FIG.|

INVENTOR LAWRENCE E. 'RIETH' ATTORNEYS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to rugged, waterproof lamp assemblies, principally for the automotive field and particularly to a lamp assembly for illuminating license plates and the like.

2. Description of the Prior Art License lamp assemblies are relatively small, are carried on the automotive body, generally in conjunction with the front or rear bumper and as such as exposed to extreme weather conditions and substantial vibration during vehicle operation. In the past, such license lamp assemblies included a cylindrical outer bushing, a lamp socket which is coaxially positioned therein for holding a light bulb in place, with both the socket and a locking ring normally snapped in place. Of necessity, the interior of the socket and that portion of the bushing carrying the lamp must be watertight. conventionally, current license lamp designs employ formed .l-slots for removably receiving the light bulb, a peripheral seal and a snap ring for coupling the peripheral seal to the same. This type of socket has caused many problems. The snap rings are not held dimensionally accurate, thus causing either a loose condition and leakage when the socket is snapped into the bushing or a tight condition in which case it is very difficult and almost impossible to snap the socket into the bushing. Further, if a loose condition exists, the socket and the wire assembly may come out of the bushing during vibration tests, during shipment or during use by the purchaser. Attempts have been made to eliminate or at least reduce the problem of the socket coming out of the bushing. The problem has been partially corrected by pressing a stabilizing ring into the socket about half way down its length. The purpose of the stabilizing ring makes it extremely difficult to remove the socket from the bushing.

Another problem present in conventional designs is that, after insertion of the socket into the bushing, and release of the snap ring, if the socket is removed for any reason and reinserted, the deformation of the snap ring tends to permit a looser fit than previously, and certainly one which is less desirable. Further, the prior art designs are unnecessarily complicated and even where initial water tight connection occurs with the snap ring type of socket, the seal may easily be destroyed during shipment or use as a result of vibration, etc. Further, such designs are relatively costly due to the necessary precision of the parts forming the same.

SUMMARY OF THE INVENTION This invention is directed to a lamp assembly in which the socket connection within the bushing is in the form of a posi' tive mechanical lock. The seal lies between the socket and the bushing in such a location that the socket may preferably be provided with open .l-slots for receiving the lamp. The single seal which facilitates completion of the positive mechanical lock also seals the socket in the bushing in two directions and seals the lead wire which enters the socket.

Specifically, the lamp assembly consists of a cylindrical bushing which receives in concentric fashion an inserted cylindrical light bulb socket with a light bulb carried at one end of the socket and a lead wire extending from the opposite end thereof. The bushing is counterbored at the rear end forming a shoulder intermediate the ends of the inserted socket. A unitary cup-shaped boot of resilient, nonconductive material surrounds the rear portion of the inserted socket with a full peripheral portion sandwiched between the socket and the bushing and pressed against the shoulder to form both an axial and radial seal with the bushing. The socket includes a radially projecting ring on its outer periphery which is located axially behind the shoulder and within the counter bore such that a portion of the boot extends inwardly beyond the ring in contact with the shoulder to enhance the seal caused by the boot being located between the socket ring and the shoulder formed by the bushing counterbore.

The main bore of the bushing includes opposed longitudinal slots and a second counterbore is formed at the front end of the bushing. The front shoulder formed thereby, carries a shallow recess adjacent each slot. The socket includes radially projecting tabs corresponding to each bushing slot whereby, during insertion of the socket and the overlying boot, the leading peripheral portion of the resilient boot is pressed against the rear shoulder allowing the tab to emerge from the front end of its respective slot and as a result of slight rotation of the socket with respect to the cylindrical bushing, each tab is received within a respective shoulder recess adjacent the slot and maintained within said recess under the bias provided by the resilient boot. The lead wire projects through a central recess in the rear of cup-shaped boot and carries an enlarged diameter terminal at the inner end thereof, the boot sealingly surrounding the lead wire. A coil spring is positioned between the terminal and the bottom of the cup-shaped boot to bias the lead wire terminal into contact with the inner end of the inserted bulb.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of the improved license lamp assembly of the present invention;

FIG. 2 is a sectional view of the assembly shown in FIG. 1;

FIG. 3 is an end view in section of the assembly of FIGS. 1 and 2 taken about lines 3-3 of FIG. 2, with the lamp removed;

FIG. 4 is a partial sectional view of the elements forming the assembly during insertion of the socket and boot into the bushing receiving the same.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawing, the improved automotive license lamp assembly 10 of the present invention comprises three main parts, a die cast metal bushing 1.2, a formed tubular light bulb socket 14, and a cup-shaped nonconductive, resilient boot 16 preferably formed of rubber or flexible plastic material. The die cast bushing 12 is formed of a conductive material, such as metal, and is externally threaded at 18 so that it may be received within a suitable aperture formed in the automotive body or bumper (not shown) and to which is then coupled a nut (not shown) for locking the lamp assembly 10 in position. Bushing I2 is further provided with a radially projecting flange portion 20 at the forward or front end of the assembly which is internally recessed at 22 to receive a clear glass dome-shaped window or cover 24. A sealing ring 26 having an outer diameter on the order of recess 22 is sandwiched between the bushing 12 and the glass cover 24. A stamped metal ring or rim member 28 has its inner edge 30 clamped over the flange 20 and acts in conjunction with an outer edge 32 to maintain the glass window 24 in sealed position on the bushing. A sector-shaped hood 34 overlies a portion of the glass cover 24 such that a narrow beam of light is permitted through the glass cover 24 as indicated by dotted lines 36. Ring 28 and widow 24 are conventional in license lamp assemblies ofthis type.

The cylindrical bushing 12 is provided with a central, relatively small diameter bore 38, bore 38 being counterbored at the rear as indicated at 40 and counterbored at 42 at the forward or front end thereof. Bore 38 and front counter bore 42 from front shoulder 44 which contains the shallow recesses or depressions 52. Bore 38 and the rear counter bore 40 form rear shoulder 46. The small diameter bore 38 is provided with a pair of opposed longitudinal slots 50 which extend its complete length. To the side of these slots, in the same circumferential direction, are provided the shallow recesses or depressions 52 within annular shoulder 44.

The specially formed light bulb socket 14 comprises a stamped, thin, metal cylindrical or tubular member having a cylindrical portion 54 which is of a diameter slightly less than the diameter of the bore 38 and is coaxially positioned within the bushing. At the inner end of the cylindrical portion 54, there are provided a like number of radially projecting tabs 56 which extend radially a distance in excess of bore 38 but less than counterbore 42. During insertion of the socket 14 within the bushing, the locking tabs 56 move through the longitudinal slots 50 which are of a width in excess of the width of locking tabs 56 until the tabs project axially beyond the slots, whereupon the socket is rotated counterclockwise as shown in FIG. 3 until the tabs 56 overlie recess or depressions 52 formed within annular shoulder 44.

Further, the thin wall, metal socket 14 is provided with a pair of opposed J-shaped, open slots 58 which extend from the inner edge 60 of the socket along a portion of'its length. Each slot 58 is provided with longitudinal portion 62 and a right angle locking portion 64. In conventional fashion, a small electric lamp 66 includes a cylindrical metallic base 68 having a pair of pins 70 projecting radially therefrom in conventional fashion. Further, the rear end of the socket 14 is provided with a reversely bent, laterally extending terminal portion forming an annular rim 71. In conventional fashion, the lamp is connected to a source of electrical energy (not shown) through a conventional insulated lead wire 72, the lead wire terminating at its inner end in a metal, contact terminal 74 of enlarged diameter which carries an even larger diameter dome-shaped head 76. Terminal 74 is received within a cylindrical member 78 formed of insulative material, which may be plastic or otherwise, the cylindrical member 78 having a bore 80 on the order of terminal 74. The cylindrical member 78 is further provided with a radial flange 82 of a diameter on the order of the inner diameter of socket cylindrical portion 54 with the bulb base 68 terminating in a dome-shaped contact 84. A small coil spring 86 is positioned between the annular rim 71 of the socket and the flange 82 of the cylinder carrying the lead wire terminal 74. The coil spring 86 biases the domeshaped head 76 of the lead wire terminal against the domeshaped contact 84 carried by the light bulb 66.

The third principal part of the license lamp assembly of the present invention, is the unitary flexible, resilient boot 16 which comprises a molded plastic or rubber cup-shaped member having portions of varying diameter and which serves both as a double seal against the bushing and as a compression member to cause the socket and boot assembly to flt tightly into the bushing. As such, the boot, as shown in cross section in FIGS. 2 and 4, consists of a main cylindrical portion 87 having an internal diameter slightly on the order of the socket cylinder 54 so as to snugly flt about the outer periphery of the socket at the rear end thereof. The socket is further provided with a radially projecting, annular ring 88 which extends about the periphery of cylinder 54 inten'nediate of its ends. Further, the main cylindrical portion 87 of the boot I6 is provided with an enlarged diameter portion 90 at the forward end thereof which rides over the annular ring 88. During coupling of the boot to the socket rear wall 92 of the boot abuts rim 71 of the socket 14. The boot 16 preferably adhesively attached to the socket 14 by epoxy or vinyl cement 89. The unitary, molded boot 16 terminates in reduced

diameter portions

94 and 96 with the internal diameter of portion 96 of the boot being slightly less than the diameter of the insulated lead wire 72 such that portion 96 of the boot sealingly embraces the lead wire to seal to rear end of the lamp assembly.

With the lamp 66 in the position shown in FIG. 4, such that the pins 70, carried by lamp base 66 are locked under the spring bias of coil spring 86, the subassembly of lamp 66, socket 14, lead wire 72 and boot 16 are ready for insertion into bushing 12 as indicated in FIG. 4. When the socket I4 is inserted into the bushing 12, the right angle locking tabs 56 easily slide through the longitudinal slots 50 in the bushing until they reach shoulder 44. The socket 14 is then rotated counterclockwise as seen in FIG. 3 thus placing the tabs 56 within tab receiving recesses 52.

The socket is thus resiliently locked into place and can only be removed by rotating it to again line up the tabs 56 with the longitudinal slots 50. The boot is rriolded from a rubber or flexible plastic compound which in turn is securely bonded to the socket periphery by the epoxy or vinyl adhesive 89. If the bond fails the lamp will leak. when the socket is inserted into the bushing, the boot fits snugly into the enlarged bore 40 of the bushing. As the locking tabs on the socket get close to the top of slots 50, the inner tapered terminal end of the boot butts up against shoulder 46. As the socket I4 and the boot 16 are pushed in completely, the boot l6 compresses against shoulder 46, thus providing an axial seal. The boot also expands radially against counterbore 40 providing an additional radial seal. Further, the boot itself acts as the compression member to cause the socket and boot assembly to fit tightly into the bushing since, the socket is inserted to fit tightly into the bushing since, the socket is inserted to such an extent that the locking tabs 56 move out of their longitudinal slots 50'and upon rotation contact shoulder 44. There are preferably stops (not shown) which will not allow the part to be rotated clockwise and which will not allow the part to be rotated any further counterclockwise than the depressions 52, and since the depressions are axially to the rear of the main portion of shoulder 46, there is a slight relaxation of portions 90 of the boot captured between ring 88 and shoulder 46 with the resilience of the same maintaining a tight fit between tabs 56 and the tab receiving depressions 52. To remove the socket and the components held thereby from bushing 12, a reverse procedure to that employed in insertion is required.

From the above, it is certainly apparent that the socket itself may have open .l-slots without destroying the seal between the bushing and the slots which greatly reduces the cost of manufacture of the socket itself. The socket and boot assembly lock positively into the bushing with the boot serving as a double seal against the bushing both radially and axially. The boot further serves to seal the terminal lead wire and functions as the compression member to cause the socket and boot assembly to fit tightly into the bushing while maintaining the positive lock between the socket and the bushing.

I claim:

1. A lamp assembly comprising in combination:

a cylindrical bushing, a cylindrical light bulb socket coaxially inserted within said bushing, a light bulb carried at one end thereof, means for positively locking said socket within said bushing and a unitary, resilient flexible, nonconductive cup-shaped boot receiving the rear end of said socket and having a full peripheral portion abutting said bushing to seal the same subsequent to insertion of said socket into said bushing and locking of the same.

2. The lamp assembly as claimed in claim I wherein said bushing includes at least one longitudinal slot formed therein, a counterbore formed at the front of said bushing to form a front shoulder, an axial recess within said shoulder adjacent each slot, a radially projecting tab carried by said socket corresponding to each slot in the bushing whereby; during insertion of said socket and said overlying boot, the peripheral portions of said boot is pressed between said socket and said bushing to resiliently allow each tab to emerge from the front end of its slot and to move circumferentially into the adjacent recess of said shoulder to maintain said socket in positive locking position under the bias of said resilient boot.

3. The lamp assembly as claimed in claim 2 further comprising a pair of opposed, open .l-slots carried by said socket and wherein said bulb carries a pair of radially projecting pins, received by said slot, to locate said bulb in proper position within said socket.

4. The lamp assembly as claimed in claim 3 further comprising a lead wire carried by said assembly and passing through the rear of said cup-shaped boot, an enlarged contact terminal carried by said lead wire at the inner end thereof, and means carried by said socket, for biasing the contact terminal into contact with the end of said bulb.

5. The lamp assembly as claimed in claim 4 wherein said cylindrical light bulb socket terminates at its rear in a reversely curved, inwardly directed rim and said biasing means comprises a coil spring, one end of which is carried by said annular rim, and said assembly further comprises a nonconductive cylindrical receiving the said lead wire terminal, and a radial flange formed on said nonconducting cylinder of a diameter slightly less than the internal diameter of said socket whereby the inner end of said coil spring is in contact with said flange to bias said lead wire contact terminal into contact with the end of said light bulb.

6. The lamp assembly as claimed in claim 1 wherein said bushing is counterbored at the rear end thereof to form a shoulder lying intermediate the ends of said socket when locked therein, with a second peripheral portion of said boot being compressed against said shoulder to maintain a tight fit between said boot and said bushing.

7. The lamp assembly as claimed in claim 6 wherein said bushing is counterbored at the forward end thereof, the central bore of said bushing includes at least one longitudinal slot extending the length thereof, a recess adjacent each slot on the forward shoulder, and said socket includes a radially projecting tab corresponding to each slot in the bushing whereby; during insertion of said socket and overlying boot, said resilient boot is pressed against said rear shoulder to resiliently allow said tab to emerge from its respective slot and to move circumferentially into an adjacent recess under the bias offered by said resilient boot to positively lock the socket in position within said bushing.

8. The lamp assembly as claimed in claim 6 further comprising a radially projecting ring carried by said socket on its outer periphery and spaced axially to the rear of said shoulder and within said counterbore, whereby; said peripheral portion of said boot is compressed radially between said ring and said counterbore and axially between said ring and said shoulder.

9. The lamp assembly as claimed in claim 8 wherein said bushing is counterbored at the forward end thereof to form a front shoulder, the central bore between counter bores includes at least one longitudinal slot extending the length thereof, said from shoulder carries a recess adjacent each slot, and said socket includes a radially projecting tab corresponding to each slot in the bushing; whereby during insertion of said socket and overlying boot, the resilient peripheral portions of said boot are pressed radially between said ring and said counterbore and axially between said ring and said rear shoulder to resiliently allow said tab to emerge from the front end of said slot and to move circumferentially into an adjacent recess under the bias offered by said resilient boot.

10. The lamp assembly as claimed in claim 9 wherein said cylindrical light bulb socket terminates in a reversely curved inwardly directed lateral edge to form an annular rim, said lead wire terminates at its inner end in an enlarged diameter, headed contact terminal, the base of said contact terminal being received by a nonconducting cylinder, a flange is formed on said nonconducting cylinder having a diameter on the order of the internal diameter of said cylindrical socket, and a coil spring has one end received within said annular rim and the other end engaging the face of said radial flange whereby said coil spring forces said headed terminal of said lead wire into contact with the inner end ofsaid light bulb.

Claims

1. A lamp assembly comprising in combination: a cylindrical bushing, a cylindrical light bulb socket coaxially inserted within said bushing, a light bulb carried at one end thereof, means for positively locking said socket within said bushing and a unitary, resilient flexible, nonconductive cupshaped boot receiving the rear end of said socket and having a full peripheral portion abutting said bushing to seaL the same subsequent to insertion of said socket into said bushing and locking of the same.

2. The lamp assembly as claimed in claim 1 wherein said bushing includes at least one longitudinal slot formed therein, a counterbore formed at the front of said bushing to form a front shoulder, an axial recess within said shoulder adjacent each slot, a radially projecting tab carried by said socket corresponding to each slot in the bushing whereby; during insertion of said socket and said overlying boot, the peripheral portions of said boot is pressed between said socket and said bushing to resiliently allow each tab to emerge from the front end of its slot and to move circumferentially into the adjacent recess of said shoulder to maintain said socket in positive locking position under the bias of said resilient boot.

3. The lamp assembly as claimed in claim 2 further comprising a pair of opposed, open J-slots carried by said socket and wherein said bulb carries a pair of radially projecting pins, received by said slot, to locate said bulb in proper position within said socket.

9. The lamp assembly as claimed in claim 8 wherein said bushing is counterbored at the forward end thereof to form a front shoulder, the central bore between counter bores includes at least one longitudinal slot extending the length thereof, said front shoulder carries a recess adjacent each slot, and said socket includes a radially projecting tab corresponding to each slot in the bushing; whereby during insertion of said socket and overlying boot, the resilient peripheral portions of said boot are pressed radially between said ring and said Counterbore and axially between said ring and said rear shoulder to resiliently allow said tab to emerge from the front end of said slot and to move circumferentially into an adjacent recess under the bias offered by said resilient boot.

10. The lamp assembly as claimed in claim 9 wherein said cylindrical light bulb socket terminates in a reversely curved inwardly directed lateral edge to form an annular rim, said lead wire terminates at its inner end in an enlarged diameter, headed contact terminal, the base of said contact terminal being received by a nonconducting cylinder, a flange is formed on said nonconducting cylinder having a diameter on the order of the internal diameter of said cylindrical socket, and a coil spring has one end received within said annular rim and the other end engaging the face of said radial flange whereby said coil spring forces said headed terminal of said lead wire into contact with the inner end of said light bulb.