WO1999040649A1

WO1999040649A1 - Solid female pin for lamp assembly

Info

Publication number: WO1999040649A1
Application number: PCT/US1999/000841
Authority: WO
Inventors: Troy Lynn Roney; Curtis L. Lidikay
Original assignee: Grote Industries, Inc.
Priority date: 1998-02-05
Filing date: 1999-01-14
Publication date: 1999-08-12
Also published as: AU2116499A

Abstract

The present invention relates to a solid female terminal pin (50) which dramatically improves the performance of mating terminals in sealed and resealable lamp applications, such as in the commercial vehicle market. The terminal pin (50) is fabricated from solid stock on conventional screw machine equipment which allows more current-carrying capability and corrosion resistance than the prior art rolled form version. The terminal pin (50) is machined from solid brass, which facilitates resistance welding to other materials in order to provide an excellent electrical conductor. The terminal (50) has vertical slots (62) machined into the shell (52) of the terminal (50) and also a rib (60) rolled onto the internal part of the terminal (50) in order to provide the required insertion and retention characteristics of the female terminal. The terminal (50) also has a barb member (72) around the periphery of the terminal (50) which provides an annular seal when the terminal (50) is pressed into a plastic housing.

Description

SOLID FEMALE PIN FOR LAMP ASSEMBLY

TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to lamp assemblies and, more particularly, to a solid female pin for use in lamp assemblies.

BACKGROUND OF THE INVENTION

In sealed and resealable lamp assemblies, a variety of terminals are used in the prior art to carry electrical current to the bulb or bulb/track subassemblies. In the commercial vehicle market, the geometry of the female terminals in such lamp assemblies is standardly 0J 80 inches in diameter and these terminals are available from various manufacturers. A typical prior art terminal is illustrated in plan view in FIG. 1 and in cross-sectional view in FIG. 2, and is indicated generally at 10. The prior art terminals 10 are all roll-formed or manufactured from metal sheet stock and rolled into the illustrated configuration in order to mate with the standard male terminal fabricated in the same manner (not shown). The connector 10 incorporates a barrel body 12 transitioning to a flared insertion end 14. A gap 16 runs longitudinally therethrough, the gap 16 resulting from cutting the terminal 10 from sheet stock and rolling it into the configuration illustrated in FIGS. 1 and 2. A relatively flat terminal tab 18 extends from the barrel body 12 at the end opposite the flared portion 14. The advantage of the prior art terminal 10 design is a relatively low manufacturing cost per piece part and one that is flexible to provide the necessary insertion and retention characteristics for the mated male and female pins. The disadvantages of the prior art terminal 10 design is that it is very difficult to seal the terminal reliably in a plastic housing, the terminal exhibits limited current-carrying capability and resistance to corrosion, and the overall ruggedness of the terminal 10 for 2 the commercial vehicle market is questionable, particularly with multiple insertions and removals of the male pin. Of these problems, the difficulty in sealing the terminal 10 reliably in a plastic housing is particularly troublesome, because such lamp assemblies are used on commercial vehicles in adverse environmental conditions, and it is desirable for such assemblies to be "weather-tight" in order to prevent shorting and/or corrosion of the electrical parts interior thereto.

There is therefore a need for a female terminal pin design which allows the terminal to be reliably sealed in a plastic housing, which exhibits increased current carrying capability and resistance to corrosion. The present invention is directed toward meeting these needs.

3 SUMMARY OF THE INVENTION

The present invention relates to a solid female terminal pin which dramatically improves the performance of such mating terminals in sealed and resealable lamp applications, such as in the commercial vehicle market. The terminal pin is fabricated from solid stock on conventional screw machine equipment which allows more current-carrying capability and corrosion resistance than the prior art rolled form version. The terminal pin is machined from solid brass, which facilitates resistance welding to other materials in order to provide an excellent electrical conductor. The terminal has vertical slots machined into the shell of the terminal and also a rib rolled onto the internal part of the terminal in order to provide the required insertion and retention characteristics of the female terminal. The terminal also has a barb member around the periphery of the terminal which provides an annular seal when the terminal is pressed into a plastic housing. In one form of the invention, a female terminal pin is disclosed, comprising: a substantially cylindrical body section having a proximal end and a distal end, the body section having a first diameter; a head coupled to the body section proximal end, the head having a second diameter greater than the first diameter; and a barb extending at least partially around an exterior surface of the body section, the barb comprising: a camming surface extending away from the body section exterior surface at an angle; and an annular ledge extending from the body section exterior surface to the camming surface.

In another form of the invention a female terminal pin is disclosed, comprising: a substantially cylindrical body section having a closed proximal end, a hollow internal cavity and an open distal end communicating with the hollow internal cavity, the body section having an exterior surface having a first diameter; a head coupled to the body section proximal end, the head having a second diameter greater than the first diameter; a barb extending completely around an exterior surface of the body section, the barb comprising: a camming surface extending away from the body section exterior surface at an angle; and an annular ledge extending from the body section 4 exterior surface to the camming surface; at least one slot in the body section extending from the distal end and further extending between the body section exterior surface and the hollow internal cavity; and a convex rib surface extending at least partially around an interior surface of the hollow internal cavity.

5 BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a prior art female terminal.

FIG. 2 is a cross-sectional view of the prior art female terminal of FIG. 1.

FIG. 3 is an isometric view of a preferred embodiment solid female pin of the present invention.

FIG. 4 is a side elevational view of the preferred embodiment pin of FIG. 3.

FIG. 5 is a cross-sectional view of the preferred embodiment pin of FIGS. 3 and 4.

6 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. A preferred embodiment of the solid female pin of the present invention is illustrated in FIGS. 3-5, and indicated generally at 50. The solid female pin terminal 50 of the present invention is designed to dramatically improve the performance of the terminal 50 in sealed and resealable lamp applications (incandescent, LED, etc.). The pin terminal 50 has a generally cylindrical body section 52 having an open distal end 54 and a closed proximal end 56. The open distal end 54 is provided for insertion of a complementary male terminal pin (not shown). A rib 58 is rolled into the cylindrical body portion 52, creating a convex rib surface 60 on the interior surface of the body section 52 (see FIG. 5) in order to provide desirable insertion and retention characteristics when the male pin is inserted therein. The terminal pin 50 further includes at least one and preferably two vertical slots

62 formed into the cylindrical body section 52 and extending completely to the distal end 54. These vertical slots 62 allow the terminal pin 50 to flex slightly as the male pin is inserted therein, thereby also providing desirable insertion and retention characteristics. The proximal end 56 of the terminal pin 50 preferably includes a flat portion 64 and raised central hump 66 in order to facilitate resistance welding of a terminal connector thereto. Different configurations of the proximal end 56 will also be apparent to those having ordinary skill in the art in order to facilitate secondary processes such as staking, riveting, or soldering to wire or track circuits.

The solid female terminal pin 50 is designed to be inserted through a hole in the wall of a lamp assembly from the interior of the lamp assembly. In order to facilitate 7 this function, the terminal pin 50 includes a chamferred edge 68 at the exterior peripheral edge of the distal end 54, which facilitates guiding the terminal pin 50 into the mounting hole. An annular head 70 near the proximal end 56 serves to seat the terminal pin 50 within the hole when it has been inserted fully therein. In order to provide excellent sealing characteristics between the terminal pin 50 and the lamp assembly into which it is inserted, the terminal pin 50 includes an annular barb 72, preferably extending completely around a periphery of the cylindrical body section 52. The barb 72 includes a camming surface 74 which is angled outward from the exterior surface of the cylindrical body section 52 toward the head 70. The camming surface 74 preferably makes a 15° angle with the exterior surface of the cylindrical body portion 52. The barb 72 further includes an annular ledge 76 transitioning between the proximal edge of the camming surface 74 and the cylindrical body section 52, the ledge 76 being substantially perpendicular to the cylindrical body section 52. It can thus be seen that, when the terminal pin 50 is inserted into its mounting hole, the chamferred edge 68 facilitates insertion of the pin 50 into the hole, camming surface 74 pushes the plastic of the mounting hole away from the terminal pin 50 (the diameter of the mounting hole is substantially equal to the diameter of the cylindrical body portion 52), thereby allowing the terminal pin 50 to be inserted into the hole until the head 70 seats against the surface into which the mounting hole is formed. Because the inside diameter of the mounting hole is substantially equal to the outside diameter of the cylindrical body portion 52, the plastic of the mounting hole lying between the barb 72 and the head 70 will tend to prolapse back against the cylindrical body portion 52 after having been pushed away by the camming surface 74. Once the plastic of the mounting hole prolapses back into this area, the ledge 76 has effectively dug into the walls of the mounting hole, thereby preventing the terminal pin 50 from being backed out of the mounting hole. Additionally, interaction of the barb 72 surfaces with the interior of the mounting hole, as well as interaction of the head 70 with the surface into which the mounting hole is formed provides an extremely effective weather-tight seal. 8

The solid female terminal pin 50 of the preferred embodiment is preferably fabricated from solid brass stock on conventional screw machine equipment. This allows the terminal pin 50 to be formed without the gap 16 exhibited by the prior art terminal 10, thereby further increasing its ability to form a weather-tight seal within the lamp assembly.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

Claims

WHAT IS CLAIMED IS:

1. A female terminal pin, comprising: a substantially cylindrical body section having a proximal end and a distal end, the body section having a first diameter; a head coupled to the body section proximal end, the head having a second diameter greater than the first diameter; and a barb extending at least partially around an exterior surface of the body section, the barb comprising: a camming surface extending away from the body section exterior surface at an angle; and an annular ledge extending from the body section exterior surface to the camming surface.

2. The pin of claim 1 , wherein the body section and the head are integrally formed from a single piece of material.

3. The pin of claim 2, wherein the material is brass.

4. The pin of claim 1 , wherein the barb extends completely around a circumference of the body section exterior surface.

5. The pin of claim 1 , wherein the angle is fifteen degrees.

6. The pin of claim 1, wherein the annular ledge extends substantially perpendicularly from the body section exterior surface.

7. The pin of claim 1, further comprising a hollow internal cavity extending from the distal end and into the body section. 10

8. The pin of claim 7, wherein the proximal end is closed.

9. The pin of claim 7, further comprising at least one slot in the body section extending from the distal end and further extending between the body section exterior surface and the hollow internal cavity.

10. The pin of claim 9, wherein the at least one slot comprises two diametrically opposed slots.

11. The pin of claim 7, further comprising a convex rib surface extending at least partially around an interior surface of the hollow internal cavity.

12. The pin of claim 11 , wherein the convex rib surface extends completely around a circumference of the hollow interior cavity.

13. A female terminal pin, comprising: a substantially cylindrical body section having a closed proximal end, a hollow internal cavity and an open distal end communicating with the hollow internal cavity, the body section having an exterior surface having a first diameter; a head coupled to the body section proximal end, the head having a second diameter greater than the first diameter; a barb extending completely around an exterior surface of the body section, the barb comprising: a camming surface extending away from the body section exterior surface at an angle; and an annular ledge extending from the body section exterior surface to the camming surface; at least one slot in the body section extending from the distal end and further extending between the body section exterior surface and the hollow internal cavity; and 11 a convex rib surface extending at least partially around an interior surface of the hollow internal cavity.

14. The pin of claim 13, wherein the body section and the head are integrally formed from a single piece of material.

15. The pin of claim 14, wherein the material is brass.

16. The pin of claim 13, wherein the angle is fifteen degrees.

17. The pin of claim 13, wherein the annular ledge extends substantially perpendicularly from the body section exterior surface.

18. The pin of claim 13, wherein the at least one slot comprises two diametrically opposed slots.