IP Library › Granted Patent US 7,201,059
Granted Patent B2
US 7,201,059 · App. 11/053,693 · Granted Apr 10, 2007

Magnetic force sensor assembly for workholding fixtures

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Quick Facts
Patent No.
US 7,201,059
App. No.
11/053,693
Granted
Apr 10, 2007
Kind
B2
Abstract

A magnetic force sensor assembly for a workholding fixture includes a magnetic force switch operatively supported by a base of a component disposed on the workholding fixture. The magnetic force sensor assembly also includes a sensor operatively supported by the base of the component to sense a position change of the magnetic force switch and inform a controller that there is sufficient magnetic force between the workholding fixture and the base.

Claims (57)

1. A magnetic force sensor assembly for a workholding fixture comprising:

a magnetic force switch operatively supported by a base of a component disposed on the workholding fixture, said magnetic force switch including a sensing element disposed above the base of the component and movable relative to the base of the component; and

a sensor operatively supported by the base of the component to sense a position change of said sensing element of said magnetic force switch and inform a controller that there is sufficient magnetic force between the workholding fixture and the base.

2. A magnetic force sensor assembly for a workholding fixture comprising:

a magnetic force switch operatively supported by a base of a component disposed on the workholding fixture;

a sensor operatively supported by the base of the component to sense a position change of said magnetic force switch and inform a controller that there is sufficient magnetic force between the workholding fixture and the base; and

wherein said magnetic force switch comprises a post at least partially disposed in an instrumentation cavity of the base.

3. A magnetic force sensor assembly as set forth in claim 2 wherein said post is fixed relative to the base.

4. A magnetic force sensor assembly as set forth in claim 2 wherein said post is movable relative to the base.

5. A magnetic force sensor assembly as set forth in claim 2 wherein said post is made of a non-ferrous material.

6. A magnetic force sensor assembly as set forth in claim 2 wherein said post is made of a ferrous material.

7. A magnetic force sensor assembly as set forth in claim 2 wherein said post has a head portion extending radially and a shaft portion extending axially from said head portion.

8. A magnetic force sensor assembly as set forth in claim 7 wherein said shaft portion has a threaded end portion threadably engaging a threaded portion of the instrumentation cavity.

9. A magnetic force sensor assembly as set forth in claim 7 wherein said shaft portion has a cavity extending axially therein.

10. A magnetic force sensor assembly as set forth in claim 9 including a spring at least partially disposed in said cavity between a top of said cavity and a bottom of the instrumentation cavity.

11. A magnetic force sensor assembly as set forth in claim 10 wherein said spring comprises a coil spring.

12. A magnetic force sensor assembly as set forth in claim 7 including a sensing plate cooperating with said shaft portion.

13. A magnetic force sensor assembly as set forth in claim 12 wherein said sensing plate is disposed about said shaft portion and movable relative to said shaft portion.

14. A magnetic force sensor assembly as set forth in claim 12 wherein said sensing plate is attached to said shaft portion and fixed relative to said shaft portion.

15. A magnetic force sensor assembly as set forth in claim 12 wherein said sensing plate is made of a ferrous material.

16. A magnetic force sensor assembly as set forth in claim 12 including a spring disposed about said shaft portion between said sensing plate and a bottom of the instrumentation cavity.

17. A magnetic force sensor assembly as set forth in claim 12 wherein said sensing plate has a diameter greater than a diameter of the instrumentation cavity.

18. A magnetic force sensor assembly as set forth in claim 7 including a sleeve disposed in the instrumentation cavity and about a portion of said shaft portion, said shaft portion being movable relative to said sleeve.

19. A magnetic force sensor assembly as set forth in claim 18 wherein said sleeve is made of a non-ferrous material.

20. A magnetic force sensor assembly as set forth in claim 1 wherein said magnetic force switch comprises a spacer supported by the base.

21. A magnetic force sensor assembly as set forth in claim 20 including a spring having a first end supported by said spacer and a second end cantilevered over the base.

22. A magnetic force sensor assembly as set forth in claim 21 wherein said spring is a leaf spring.

23. A magnetic force sensor assembly as set forth in claim 21 wherein said spring is a made of a carbon steel.

24. A magnetic force sensor assembly as set forth in claim 21 including a contact tip supported by said second end of said spring.

25. A magnetic force sensor assembly as set forth in claim 24 wherein said contact tip is a made of a carbon steel.

26. A magnetic force sensor assembly as set forth in claim 21 including a fastener extending through said first end of said spring and said spacer to secure said spring and said spacer to the base.

27. A magnetic force sensor assembly for a workholding fixture comprising:

a magnetic force switch operatively supported by a base of a component disposed on the workholding fixture;

a sensor operatively supported by the base of the component to sense a position change of said magnetic force switch and inform a controller that there is sufficient magnetic force between the workholding fixture and the base; and

wherein said sensor is disposed in a recess in a top surface of the base.

28. A magnetic force sensor assembly as set forth in claim 1 wherein said sensor is a proximity sensor.

29. A workholding fixture comprising:

a magnetic chuck;

a component disposed on a surface of said magnetic chuck and having a base held by a magnetic field to the surface of said magnetic chuck;

a magnetic force switch operatively supported by said base; and

a sensor operatively supported by said base to sense a position change of said magnetic force switch and inform a controller that there is sufficient magnetic force between said magnetic chuck and said base.

30. A magnetic force sensor assembly for a workholding fixture comprising:

a magnetic force switch operatively supported by a base of a component disposed on the workholding fixture, said magnetic force switch comprising a post at least partially disposed in an instrumentation cavity of the base;

said post being made of a non-ferrous material and having a head portion extending radially and a shaft portion extending axially from said head portion, said shaft portion having a threaded end portion threadably engaging a threaded portion of the instrumentation cavity;

a sensing plate made of a ferrous material disposed about said shaft portion and movable relative to said shaft portion;

a spring disposed about said shaft portion between said sensing plate and a bottom of the instrumentation cavity; and

a proximity sensor operatively supported by the base of the component to sense a position change of said magnetic force switch and inform a controller that there is sufficient magnetic force between the workholding fixture and the base.

31. A magnetic force sensor assembly for a workholding fixture comprising:

a magnetic force switch operatively supported by a base of a component disposed on the workholding fixture, said magnetic force switch comprising a post at least partially disposed in an instrumentation cavity of the base;

said post being made of a non-ferrous material and having a head portion extending radially and a shaft portion extending axially from said head portion, said shaft portion having a cavity extending axially therein;

a sleeve made of a non-ferrous material disposed in the instrumentation cavity and about a portion of said shaft portion, said shaft portion being movable relative to said sleeve;

a spring at least partially disposed in said cavity between a top of said cavity and a bottom of the instrumentation cavity;

a proximity sensor operatively supported by the base of the component to sense a position change of said magnetic force switch and inform a controller that there is sufficient magnetic force between the workholding fixture and the base.

32. A magnetic force sensor assembly for a workholding fixture comprising:

a magnetic force switch operatively supported by a base of a component disposed on the workholding fixture, said magnetic force switch comprising a spacer supported by the base, a leaf spring having a first end supported by said spacer and a second end cantilevered over the base, and a contact tip supported by said second end of said spring;

a fastener extending through said first end of said spring and said spacer to secure said spring and said spacer to the base; and

a proximity sensor operatively supported by the base of the component to sense a position change of said magnetic force switch and inform a controller that there is sufficient magnetic force between the workholding fixture and the base.

Assignments (1)
RELEASE OF SECURITY INTEREST Recorded Nov 7, 2014
From: WILMINGTON TRUST COMPANY
To: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Reel/Frame 034371/0676 →