Lamp Assembly

This invention relates to lamp assemblies and, more particularly, to lamp assemblies particularly suited for automotive applications.

A myriad of lamp assembly designs have been proposed and/or utilized for automotive lamp applications such, for example, as tail light assemblies. While these prior art devices have in general provided satisfactory and reliable lighting, they have also each embodied certain limitations. Specifically, automotive lamp applications dictate rather strong moisture sealing requirements. Moisture sealing in prior art designs have been accomplished either by encapsulating or "potting" the entire lamp assembly in a plastic substance, or by packing the various lamp cavities with a grease compound. Both prior art sealing concepts embody two basic shortcomings. Specifically, the sealed lamp is difficult to work with in the original automobile assembly process since, once assembled as a sealed unit, it must thereafter be handled as a single, non-divisible, sealed entity and special care must be taken to avoid derogation of the seal. Further, if the lamp is thereafter disassembled for any reason, the seal is destroyed and cannot be readily reestablished.

It is accordingly an object of the present invention to provide a lamp assembly for automotive applications or the like in which the lamp may be selectively assembled in the specific manner and sequence that is most compatible with the original automobile assembly process and which may thereafter be readily disassembled and/or reassembled without derogation of the seal.

This object is accomplished in accordance with the present invention by the provision of a lamp assembly in which moisture sealing is accomplished throughout the assembly by resealable mechanical means. The invention lamp assembly includes a socket assembly, a base, and a plurality of elongated conductors. One end of the socket assembly is sealingly but releasably mounted in one face of the base with contacts on the mounted socket assembly end positioned in a socket cavity in the base, and the elongated conductors pass sealingly through a wall of the base to position their inboard ends in the socket cavity in respective electrical connection with the contacts of the socket assembly.

According to a further feature of the invention, the lamp assembly further includes a connector having a plurality of terminals adapted to respectively electrically connect with the outboard ends of the conductors. In the disclosed preferred embodiment of the invention, the connector terminals are positioned in one end of the connector; that end of the connector is sized and configured to be inserted into a connector cavity defined in the base and separated from the socket cavity by the base wall through which the elongated conductors pass; and the outboard ends of the elongated conductors are positioned in the connector cavity for respective electrical connection to the connector terminals upon insertion of the connector into the connector cavity.

According to another feature of the invention, the socket assembly includes a hollow socket and a retainer element positioned within the socket and defining a rectangular cavity for receipt of a wedge base bulb. In the disclosed embodiment of the invention, the rectangular bulb cavity is defined by a pair of opposing walls and at least one of the walls is defined by a yieldable finger which wedges open upon insertion of the bulb to allow passage of the leading edge of a collar on the base of the bulb and thereafter snaps back to releasably grasp the bulb collar.

According to another feature of the invention, an electrical assembly is provided in which an elongated electrical conductor element extends through a passage in a partition of a housing assembly for electrical contact at its inboard end with an electrical terminal disposed within a sealed cavity defined by the housing assembly. The passage tapers inwardly at its inboard end to form inwardly extending lip means and the conductor element has a thickness slightly greater than the width of the passage at the lip means and slightly less than the width of the outboard end of the passage so that the conductor element, upon insertion through the passage into the cavity, coacts with the lip means to form a tight seal for the cavity at the partition and to resist withdrawal of the conductor element through the passage.

FIG. 1 is an exploded perspective view of the invention lamp assembly;

FIG. 2 is an elevational view, in cross section, of the invention lamp assembly;

FIGS. 2A and 2B are enlarged views of selected portions of FIG. 2;

FIG. 3 is a top view of the invention lamp assembly with certain elements of the assembly omitted for clarity of illustration;

FIG. 4 is a bottom perspective view of a bulb retainer element employed in the invention lamp assembly;

FIG. 5 is a perspective view of electrical contact elements employed in the invention lamp assembly;

FIG. 6 is a partially fragmentary view of the invention lamp assembly shown in association with a lamp housing and parabola; and

FIGS. 7 and 8 are views of a modified moisture sealing construction.

The invention lamp assembly, broadly considered, comprises a base 10, a connector 12, a socket 14, a bulb 16, and a bulb retainer 18.

Base 10 is formed of a resilient, plastic material such, for example, as a polyurethane or an acrylamide. Base 10 includes a socket cavity 10a opening at the upper face 10b of the base, and a connector cavity 10c opening in an end face 10d of the base. Connector cavity 10c is separated from socket cavity 10a by a wall or partition 10e. Three elongated conductor bars 20, 22, 24 of rectangular conductor bar stock, extend in parallel fashion within base 10. Bars 20, 22, 24 may, for example, be formed of beryllium copper material. One end 20a, 22a, 24a of each conductor bar is positioned in connector cavity 10c and the other end 20b, 22b, 24b of each conductor bar is supported on a platform surface 10f provided on the bottom of socket cavity 10a. Intermediate their ends, conductor bars 20, 22, 24 pass through passages 26 (FIG. 2A) extending longitudinally through partition 10e. Each passage 26 is rectangular in cross section and is necked down adjacent socket cavity 10a to form opposing lip portions 26a which taper outwardly in the direction of connector cavity 10b to blend with the main body portion 26b of the passage. Conductor bars 20, 22, 24 have a thickness that is slightly greater than the height of the opening defined between the relaxed lip portions 26a and slightly less than the height of passage portion 26b and a width that is slightly greater than the width of passage 26 so that, as the bars are selectively inserted through connector cavity 10c and through passages 26, lip portions 26a are splayed resiliently outwardly to pass the bars and allow the ends 20b, 22b, 24b to be seated on platform surface 10f. With the bars thus inserted in base 10, lip portions 26a coact with the respective upper and lower surfaces of the conductor bars and the side edges of the bars form an interference fit with the adjacent material of the base. Bars 20, 22, 24 thus form a moisture seal for socket cavity 10a at partition 10e. Lip portions 26a also coact with the engaged bar surfaces to resist withdrawal of the bars since any attempted withdrawal of a bar will tend to pivot lip portions 26a toward a more tightly closed clamping configuration. This arrangement prevents inadvertent withdrawal or displacement of the conductor bars while yet permitting withdrawal upon the application of a delibrate withdrawl force and, if desired, subsequent reinsertion for reassembly purposes.

A modified sealing and clamping construction is shown in FIGS. 7 and 8 for use in applications requiring round cross section conductors rather than the flat, rectangular conductor bar stock used for conductor bars 20, 22, 24. In the FIGS. 7 and 8 construction, circular passages 28 are provided in a partition 30 for coaction with round cross section conductors 32. Each passage 28 is necked down at one end to form an annular lip portion 28a which tapers outwardly toward the other end of the passage to blend with the main body cylindrical portion 28b of the passage. The round cross section conductor 32 has a diameter that is slightly greater than the relaxed inner diameter of annular lip portion 28a and slightly less than the diameter of main body passage portion 28b. As conductor 32 is inserted into passage 28 from the left, as seen in FIG. 7, lip portion 28a is splayed elastically outwardly to pass the conductor element (not shown) positioned in a cavity defined to the right of partition 30. Lip portion 28a thus coacts with the outer periphery of conductor 32 to form a moisture seal at the partition. Lip portion 28a also acts to resist withdrawal of conductor 32 since any attempted withdrawal will tend to pivot lip portion 28a toward a more tightly closed clamping configuration. This arrangement prevents inadvertent withdrawal or displacement of the conductor bars while yet permitting withdrawal upon the application of a deliberate withdrawal force and, if desired, subsequent reinsertion for reassembly purposes.

Connector 12 is formed of a hard, rigid, plastic material such, for example, as a polyester, phenolic or the like. Connector 12 is generally hollow and includes an upper wall 12a, a lower wall 12b, sidewalls 12c and 12d, partitions 12e and 12f, and a locking tab 12g upstanding from top wall 12a. Partitions 12e and 12f coact with sidewalls 12c and 12d to define three parallel through passages 12h, 12i and 12j. A terminal 34 is positioned at the forward end of each passage 12h, 12i and 12j. A resilient tab 12k coacts with a detent in the top wall of each terminal 34 to maintain the terminal in its forward position within the connector upon insertion of a suitable tool into the forward end of the connector to resiliently raise the respective tab 12k. Three wires 36, 38, 40 are crimped at their forward ends to a respective terminal 34 and extend rearwardly therefrom through the appropriate passage 12h, 12i, 12j. Connector 12 is sized and configured to slide snugly into the connector cavity 10c of base 10 with conductor bar ends 20a, 22a, 24a each pressing firmly into a respective terminal 34 to establish a firm electrical connection between wires 36, 38, 40 and bars 20, 22, 24. As connector 12 slides into base cavity 10c, locking tab 12 g cams upwardly over raised base portion 10g and then snaps downwardly to firmly embrace base portion 10g, firmly seat the connector in the base cavity, and preclude inadvertent withdrawal of the connector from the base. Also, as connector 12 slides into cavity 10c, resilient lip portions 10h (FIG. 2B), formed around the entire perimeter of the opening of cavity 10c in end face 10d, slidably and sealing wipe along upper and lower connector walls 12a, 12b and along connector sidewalls 12c and 12d to form a moisture seal between connector 12 and base 10 at the entrace to cavity 10c. The resilient polyurethane or the like material of lip portions 10h yield to allow insertion of the connector and conform snugly to the walls of the connector to optimize the mositure seal. If desired, wires 36, 38 and 40 may be potted into connector 12 to preclude the entry of moisture through the hollow interior of the connector.

Socket 14 is formed of a hard, rigid, plastic material such, for example, as a polyester, phenolic or the like. Socket 14 has a tubular configuration and includes a cylindrical sidewall 14a, defining a central bore 14b, and an external collar 14c. Socket 14 is received with a snap press fit in socket opening 10a of base 10. Specifically, as socket 14 is pressed downwardly into opening 10a, the chamfered leading edge portion 14d of the socket presses resiliently past an annular lip 10i in socket opening 10a and seats in an annular seat 10j defined immediately below lip 10i. At the same time, lip 10i seats in an annular notch seat 14e defined on socket 14 immediately above leading edge portion 14d, and collar 14c seats on the upper annular edge 10k of base rim portion 10l with a notch 14f in collar 14c embracing an upstanding post 10m on base 10 to insure proper indexing of socket 14 relative to base 10 during assembly and preclude subsequent inadvertent rotation of socket 14 relative to base 10. The resilient urethane or the like material of base 10 yields to allow insertion of socket 14 and conforms snugly to the inserted end of the socket to ensure an effective moisture seal for cavity 10a.

Bulb 16 is of the wedge base type and includes a glass envelope 16a housing a double filament, a glass wedge base 16b receiving and selectively exposing elements 16c of both filaments, and an external plastic collar 42 positioned at the necked down interface of the envelope 16a and wedge base 16b.

Bulb retainer 18 is formed of a hard, rigid, plastic material such, for example, as polyester, phenolic or the like. Bulb retainer 18 has a cylindrical, plug-like configuration and is received with a press fit in socket bore 14b to form a socket assembly. In assembled relation, the lower end 18a of the retainer projects slightly below the lower end of the socket. Retainer 18 includes an upstanding finger portion 18b and a rigid post portion 18c. Confronting lips 18d on finger portion 18c coact to define a generally rectangular opening 18e for receipt of bulb 16. As bulb 16 is pressed downwardly into retainer 18, wedge base 16b passes freely through opening 18e and through the opening defined between confronting rib portions 18f on post portion 18c and finger portion 18b. As the leading edge of collar 42 reaches opening 18e, collar 42 splays finger portion 18b outwardly to allow the collar to pass, whereafter finger portion 18b snaps back to firmly grasp the collar. In the inserted position of the bulb, confronting lips 18d embrace the bulb envelope 16a immediately above collar 42, confronting ribs 18f embrace the bulb base 16b immediately below collar 42, and wedge base 16b extends downwardly into a bulb cavity 18g defined between post portion 18c and finger portion 18b below ribs 18f.

The lower end of the inserted bulb coacts with three electrical contacts 44, 46, 48 (FIG. 5) encapsulated or potted in the lower end of retainer 18 to provide selective electrical communication between bulb 16 and conductor bars 20, 22, 24. Specifically, contact 44 includes a yoked upper end 44a, a bridge portion 44b, and a lower end 44c. Yoked upper end 44a embraces both sides of bulb base 16 and establishes electrical connection with exposed elements 16c of both bulb filaments. Lower end 44c establishes electrical connection with conductor bar 20. Contact 46 includes an upper end 46a, a bridge portion 46b, and a lower end 46c. Upper end 46a is positioned at one side of bulb base 16 to establish electrical connection with an exposed filament 16c of one of the bulb filaments and lower end 46c contacts conductor bar 22. Contact 46 thus establishes electrical connection between conductor bar 22 and one filament of bulb 16. Contact 48 includes an upper end 48a, a bridge portion 48b, and a lower end 48c. Upper end 48a is positioned at the other side of bulb base 16 to establish electrical connection with an exposed element 16c of the other bulb filament and lower end 48c contacts conductor bar 24. Contact 48 thus establishes electrical connection between conductor bar 24 and the other filament of bulb 16. Either filament of bulb 16 may thus be powered by powering the appropriate wire 38, 40. Contacts 44, 46, 48 are preferably formed of a beryllium copper material.

The invention lamp assembly is seen in FIG. 6 in a typical lamp environment such, for example, as an automotive tail lamp assembly. The invention lamp assembly is mounted with a twisting movement in the housing 50 of the tail lamp with cam members 14g on socket 14 coacting with suitable grooves in housing 50 to securely mount the lamp assembly in the housing. In assembled position, envelope portion 16a of bulb 16 is positioned within lamp parabola 52 to provide the required tail lamp illumination.

In operation, the heat generated by bulb 16 has the effect of heating the lamp assembly and, specifically, significantly elevating the temperature of the air in cavity 10a. When the lamp is subsequently extinguished, the air in cavity 10a cools and contracts to form a vacuum condition in the cavity. The vacuum condition in cavity 10a operates to attempt to suck moisture laden air into the cavity. If moisture is thus introduced into the cavity, galvanic action occurs at the interface of contacts 44, 46, 48 and conductors 20, 22, 24 and the resulting corrosion eventually renders the lamp inoperative. Introduction of moisture into cavity 10a is effectively precluded, however, in the invention lamp assembly by the mechanical interference seal formed at the interface of socket 14 in base 10 and at the point of passage of conductors 20, 22, 24 through partition 10e. Moisture sealing of the lamp assembly is further facilitated by the mechanical interference fit between the base and the connector.

The invention lamp assembly thus achieves effective moisture sealing by purely mechanical means and provides component parts which are readily assembled and disassembled. Since the invention lamp assembly achieves effective moisture sealing without resort to potting or grease packing, the lamp assembly may be selectively assembled in the specific manner or sequence that is most compatible with the assembly process of the apparatus or machine of which the lamp assembly will become a part. In the case of a tail lamp assembly for an automobile where the location of the lamp housing and of the vehicular wiring harness are essentially givens dictated by various automotive design and styling parameters, the various components of the invention lamp assembly may be selectively assembled, either by the parts supplier or by the orginal equipment manufacturer, in whatever sequence is most compatible with the total automotive assembly process and may be selectively connected to the lamp housing and to the wiring harness in whatever manner is most consistent with optimal assembly efficiency. The invention lamp assembly also allows later disassembly for repair without destroying the moisture seal, since the moisture seal is reestablished whenever the various components are reassembled. As compared to prior art encapsulated or grease packed lamp assemblies, the invention lamp assembly provides greater flexibility in the original assembly process, allows later repair without destruction of the moisture seal, provides a more effective moisture seal, and allows economy of manufacture by eliminating the labor and materials required to achieve the encapsulation or packing.

While preferred embodiments of the invention have been illustrated and described in detail, it will be apparent that various changes may be made in the disclosed embodiment without departing from the scope or spirit of the invention.