Electrical contact assembly

Patent metadata

Field	Value
Publication number	US-10446351-B2
Application number	US-201715614781-A
Country	US
Kind code	B2
Filing date	Jun 6, 2017
Priority date	Jun 6, 2017
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

An electrical contact assembly including an elongate stud having a coupling end and an opposing butt end, the butt end having a recess formed therein, the recess having a head portion and a shank portion defining a shoulder at a juncture therebetween, the head portion bounded by a collar and having a diameter that is larger than a diameter of the shank portion, and a contact pad having a head and a shank, the head having a top surface and a bottom surface with a tapered sidewall extending therebetween, the shank extending from the bottom surface of the head and having a diameter that is smaller than a diameter of the bottom surface, wherein the contact pad is disposed within the recess with the bottom surface of the head disposed on the shoulder and with the collar extending over and engaging the angled sidewall of the head.

First claim

The invention claimed is:

1. An electrical contact assembly comprising:
an elongate stud having a coupling end and an opposing butt end, the butt end having a recess formed therein, the recess having a head portion and a shank portion defining a shoulder at a juncture therebetween, the head portion bounded by a collar and having a diameter that is larger than a diameter of the shank portion; and
a contact pad having a head and a shank, the head having a top surface and a bottom surface with a tapered sidewall extending therebetween, the shank extending from the bottom surface of the head and having a diameter that is smaller than a diameter of the bottom surface;
wherein the contact pad is disposed within the recess such that an entirety of the contact pad is disposed within the elongate stud with no portion of the contact pad extending outside of the elongate stud, and wherein the bottom surface of the head is disposed on the shoulder with the collar extending over and engaging the tapered sidewall of the head to retain the contact pad within the recess.

2. The electrical contact assembly of claim 1 , wherein the top surface of the head has a diameter that is smaller than the bottom surface of the head.

3. The electrical contact assembly of claim 1 , wherein the top surface of the head protrudes from the recess.

4. The electrical contact assembly of claim 3 , wherein the top surface of the head is domed.

5. The electrical contact assembly of claim 1 , wherein the shank portion of the recess is bounded by a sidewall of the stud, the sidewall having a diameter that is larger than a diameter of the collar.

6. The electrical contact assembly of claim 1 , wherein the stud is formed of a first metal and the contact pad is formed of a second metal that is different than the first metal, the second metal having an electrical conductivity that is greater than an electrical conductivity of the first metal.

7. The electrical contact assembly of claim 6 , wherein the first metal is copper and the second metal is silver.

8. The electrical contact assembly of claim 6 , wherein the stud is coated with a third metal that is different than the first metal, the third metal having an electrical conductivity that is greater than an electrical conductivity of the first metal.

9. The electrical contact assembly of claim 6 , further comprising a base portion extending radially-outwardly from the butt end and defining a support surface adjacent the recess.

10. The electrical contact assembly of claim 9 , wherein the support surface is planar and is oriented perpendicular to a longitudinal axis of the stud.

11. A method of forming an electrical contact assembly, the method comprising:
providing an elongate stud having a coupling end and an opposing butt end, the butt end having a recess formed therein, the recess having a head portion and a shank portion defining a shoulder at a juncture therebetween, the head portion bounded by a collar and having a diameter that is larger than a diameter of the shank portion;
providing a contact pad having a head and a shank, the head having a top surface and a bottom surface with a tapered sidewall extending therebetween, the shank extending from the bottom surface of the head and having a diameter that is smaller than a diameter of the bottom surface;
disposing the contact pad within the recess, entirely within the elongate stud such that an entirety of the contact pad is disposed within the elongate stud with no portion of the contact pad extending outside of the elongate stud, with the bottom surface of the head disposed on the shoulder; and
deforming the collar so that the collar extends over and engages the tapered sidewall of the head to retain the contact pad within the recess.

12. The method of claim 11 , further comprising forming the stud from a first metal and forming the contact pad from a second metal that is different than the first metal, the second metal having an electrical conductivity that is greater than an electrical conductivity of the first metal.

13. The method of claim 12 , wherein the first metal is copper and the second metal is silver.

14. The method of claim 12 , further comprising coating the stud with a third metal that is different than the first metal, the third metal having an electrical conductivity that is greater than an electrical conductivity of the first metal.

15. The method of claim 11 , wherein the stud includes a base portion extending radially-outwardly from the butt end and defining a support surface adjacent the recess, the support surface defining a plane oriented perpendicular to a longitudinal axis of the stud, wherein deforming the collar comprises placing a press-fitting tool over the butt end of the stud, the press-fitting tool including an elongate cylinder having a recess formed in a tip thereof, the tip being brought into engagement with the support surface, a portion of the recess in the tip being defined by an angled sidewall within the tip, the angled sidewall within the tip engaging and forcibly deforming the collar of the stud.

16. The method of claim 15 , wherein the press-fitting tool includes an axially displaceable punch disposed adjacent the recess in the tip of the cylinder, the punch forcibly engaging the top surface of the head of the contact pad and holding the contact pad in engagement with the stud.

17. The method of claim 16 , the press-fitting tool further including a spring biasing the punch toward the tip of the cylinder.

18. The method of claim 15 , wherein the portion of the recess in the tip defined by the angled sidewall is frusto-conical in shape.

19. The method of claim 15 , wherein the top surface of the head protrudes from the recess after the collar has been deformed.

20. The method of claim 19 , wherein the top surface of the head is domed.

Assignees

• Littelfuse Inc

Inventors

• Mantoan Davide
• Ghirigato Paolo
• Crovetti Claudio

Classifications

• H01H2011/067

  by deforming, e.g. bending, folding or caulking, part of the contact or terminal which is being mounted · CPC title

• H01H11/06

  Fixing of contacts to carrier {; Fixing of contacts to insulating carrier} · CPC title

• H01H11/042

  by mechanical deformation · CPC title

• H01H1/06 Primary

  characterised by the shape or structure of the contact-making surface, e.g. grooved · CPC title

• H01H51/287

  Details of the shape of the contact springs · CPC title