Force biased spring probe pin assembly

Abstract

A force-biased spring probe pin assembly includes a barrel member having a barrel wall defining an elongate internal cavity with a lower end and an upper end. The assembly also includes a first plunger member reciprocally mounted in the internal cavity proximate the lower end of the internal cavity. A spring member is positioned in the internal cavity between the plunger member and the second end of the internal cavity. At least one cavity formed in the plunger member with a conductive bearing in the cavity in electrical contact with the plunger and with the wall of the barrel member. A force-biased spring probe pin assembly includes a barrel member having a barrel wall defining an elongate internal cavity with a lower end and an upper end. The assembly also includes a first plunger member reciprocally mounted in the internal cavity proximate the lower end of the internal cavity and a second plunger member reciprocally mounted in the internal cavity proximate the upper end of the internal cavity. A spring member is positioned in the internal cavity between the first plunger member and the second plunger member. At least one cavity formed in the first plunger member with a first conductive bearing in the cavity in electrical contact with the first plunger and with the wall of the barrel member and at least one cavity formed in the second plunger member with a second conductive bearing in the cavity in electrical contact with the second plunger and with the wall of the barrel member.

Claims

1. A force-biased spring probe pin assembly comprising: a barrel member having a barrel wall defining an elongate internal cavity with a lower end and an upper end; a plunger member reciprocally mounted in said internal cavity proximate to said lower end of said internal cavity; a spring member positioned in said internal cavity between said plunger member and said upper end of said internal cavity; first and second cavities formed within said plunger member; and a first conductive bearing in said first cavity and a second conductive bearing in said second cavity, wherein each of said first conductive bearing and said second conductive bearing is in electrical contact with said plunger member and with said barrel member forming an electrically conductive path between said plunger member and said barrel member.

2. The assembly of claim 1 further comprising: an insert formed of a non-conductive material, wherein said insert is positioned between said spring member and said plunger member.

3. The assembly of claim 1, wherein said plunger member comprises a third cavity formed within said plunger member, a fourth conductive bearing in said third cavity, wherein said fourth conductive bearing forms an electrically conductive path between said plunger member and said barrel member.

4. The assembly of claim 1 further comprising: a deformable material within said first cavity of said plunger member wherein said deformable material is positioned between an inside wall of said first cavity and said first conductive bearing, and wherein said deformable material applies a light outward force to said first conductive bearing providing improved electrical contact between said plunger member and said barrel member.

5. The assembly of claim 1 further comprising: a spring within said first cavity wherein said spring is positioned between an inside wall of said first cavity and said first conductive bearing, and wherein said spring applies a light outward force to said first conductive bearing providing improved electrical contact between said plunger member and said barrel member.

6. The assembly of claim 1 further comprising: a second plunger member reciprocally mounted in said internal cavity proximate to said upper end, wherein said plunger member mounted proximate to said lower end is a first plunger member; said spring member positioned in said internal cavity between said first plunger member and said second plunger member; at least one cavity formed within said second plunger member; and a third conductive bearing in said at least one cavity of said second plunger member, wherein said third conductive bearing forms an electrically conductive path between said second plunger member and said barrel member.

7. The assembly of claim 6, wherein said barrel member having a first opening at said lower end and a second opening at said upper end, said first plunger member comprising a first probe pin extending through said first opening and said second plunger member comprising a second probe pin extending through said second opening.

8. A force-biased spring probe pin assembly comprising: a barrel member having a barrel wall defining an elongate internal cavity with a lower end and an upper end; a first plunger member reciprocally mounted in said internal cavity proximate to said lower end of said internal cavity; a second plunger member reciprocally mounted in said internal cavity proximate said upper end of said internal cavity; a spring member positioned in said internal cavity between said first plunger member and said second plunger member; first and second cavities formed within said first plunger member with a first conductive bearing in said first cavity and a second conductive bearing in said second cavity, wherein each of said first conductive bearing and said second conductive bearing is in electrical contact with said first plunger member and in electrical contact with said barrel member forming an electrically conductive path between said first plunger member and said barrel member; and at least one cavity formed within said second plunger member with a third conductive bearing in said at least one cavity of said second plunger member, wherein said third conductive bearing is in electrical contact with said second plunger member and in electrical contact with said barrel member forming an electrically conductive path between said second plunger member and said barrel member.

9. The assembly of claim 8, wherein said first plunger member comprises a third cavity formed in said first plunger member with a fourth conductive bearing in said third cavity, wherein said fourth conductive bearing is in continuous electrical contact with said first plunger member and in continuous electrical contact with said barrel member; and at least one cavity in said second plunger member comprises a second cavity and a third cavity in said second plunger member, a fifth conductive bearing in said second cavity of said second plunger member and a sixth conductive bearing in said third cavity of said second plunger member, wherein said fifth and sixth conductive bearings are in continuous electrical contact with said second plunger member and in continuous electrical contact with said barrel member.

10. The assembly of claim 8, wherein said barrel member having a first opening at said lower end and a second opening at said upper end, said first plunger member comprising a first probe pin extending through said first opening and said second plunger member comprising a second probe pin extending through said second opening.

11. The assembly of claim 8, further comprising: a deformable material within said first cavity of said first plunger member wherein said deformable material is positioned between an inside wall of said first cavity of said first plunger member and said first conductive bearing, and wherein said deformable material applies a light outward force to said first conductive bearing providing improved electrical contact between said first plunger member and said barrel member; and a deformable material within said first cavity of said second plunger member wherein said deformable material is positioned between an inside wall of said first cavity of said second plunger member and said third conductive bearing, and wherein said deformable material applies a light outward force to said third conductive bearing providing improved electrical contact between said second plunger member and said barrel member.

12. The assembly of claim 8, further comprising: a first spring within said first cavity of said first plunger member wherein said first spring is positioned between an inside wall of said first cavity of said first plunger member and said first conductive bearing, and wherein said first spring applies a light outward force to said first conductive bearing providing improved electrical contact between said first plunger member and said barrel member; and a second spring within said first cavity of said second plunger member wherein said second spring is positioned between an inside wall of said first cavity of said second plunger member and said third conductive bearing, and wherein said second spring applies a light outward force to said third conductive bearing providing improved electrical contact between said second plunger member and said barrel member.

13. The assembly of claim 8 further comprising: an insert positioned between said first plunger member and said spring member.

14. The assembly of claim 13, wherein said insert is comprised of a non-conductive material.

Description

DESCRIPTION OF THE VIEWS OF THE DRAWINGS

(1) FIG. 1 (Prior art) is a partially transparent view of a prior art single ended spring probe pin assembly.

(2) FIG. 2 (Prior art) is a partially transparent view of a prior art dual ended spring probe pin assembly.

(3) FIG. 3 (Prior art) is a partially transparent view of a failed prior art single ended spring probe pin assembly.

(4) FIG. 4A is a partially transparent view of an example embodiment force-biased single ended spring probe pin assembly with conductive bearings in plunger cavities.

(5) FIG. 4B is a partially transparent view of an example embodiment portion of the plunger with a conductive bearing in a plunger cavity.

(6) FIG. 5 is a partially transparent view of an example embodiment force-biased dual ended spring probe pin assembly with conductive bearings in plunger cavities.

(7) FIG. 6 is a partially transparent view of an example embodiment of a spring-biased probe pin assembly with conductive bearings in plunger cavities and an insert between the plunger and the spring.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(8) Embodiments of the invention are described with reference to the attached figures. The figures are not drawn to scale and they are provided merely to illustrate the invention. Several aspects of the embodiments are described below with reference to example applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide an understanding of the invention. One skilled in the relevant art, however, will readily recognize that the invention can be practiced without one or more of the specific details or with other methods. In other instances, well-known structures or operations are not shown in detail to avoid obscuring the invention. The embodiments are not limited by the illustrated ordering of acts or events, as some acts may occur in different orders and/or concurrently with other acts or events. Furthermore, not all illustrated acts or events are required to implement a methodology in accordance with the present invention.

(9) As used herein force-biased spring probe pin assembly refers to a spring probe pin assembly that has been modified to apply a slight force that ensures good electrical contact between the plunger and the cylindrical barrel to avoid significant current from flowing through and damaging the spring.

(10) Embodiments describing force-biased spring probe pin assemblies are illustrated in FIG. 4A and FIG. 5. FIG. 4A is a force-biased single ended spring probe pin assembly 400 with a single plunger 402. FIG. 5 is a force-biased dual ended spring probe pin assembly 500 with two plungers, 402 and 502, on either end of the assembly 500. The probe pin 502 includes plunger 504 and conductive bearing 520 that are identical to plunger 404 and conductive bearing 420 respectively.

(11) As is illustrated in FIG. 4A, cavities are formed within the plunger 404. Conductive bearings 420 within these cavities provide electrical contact between the plunger 404 and the cylindrical barrel 406.

(12) As is illustrated in FIG. 4A, a deformable material 405 such as plastic or rubber may be positioned between the inner wall of the cavity in the plunger 404 and the conductive bearings 420 to apply slight outward force to the conductive bearings 420 to ensure good electrical contact between the conductive bearings 420, the plunger 404, and the cylindrical barrel member 406.

(13) Alternatively as shown in FIG. 4B, a metallic spring 407 may be positioned between the inner wall of the cavity in the plunger 404 and the conductive bearing 420 to provide a slight outward force to the conductive bearings 420 to ensure good electrical contact between the conductive bearings 420, the plunger 404, and the cylindrical barrel member 406.

(14) Three conductive bearings 420 are shown in FIG. 4A. More conductive bearings 420 may be used if desired. The bearings 420 in the embodiment force-biased spring probe pin assembly 400 are found to significantly increase the number of times the force-biased spring probe pin assembly may be used prior to failure.

(15) As is illustrated in FIG. 6, an insert 616 of a non conductive material may be positioned between the spring 408 and the plunger 404 to prevent current from flowing through and damaging the spring 408.

(16) While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only and not limitation. Numerous changes to the disclosed embodiments can be made in accordance with the disclosure herein without departing from the spirit or scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above described embodiments. Rather, the scope of the invention should be defined in accordance with the following claims and their equivalents.