Side-impact electro-mechanical accelerometer to actuate a vehicular safety device

• US 5,756,948 A
• Filed: 12/31/1996
• Issued: 05/26/1998
• Est. Priority Date: 12/31/1996
• Status: Expired due to Fees

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Breed Automotive Technology, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Grossi, Carl Thomas III, Husby, Harald Snorre
• Primary Examiner(s): Gellner, Michael L.
• Assistant Examiner(s): Friedhofer, Michael A.
• Application Number:
  US08/777,865
• Time in Patent Office: 511 Days
• Field of Search: 200/1 B, 200/1 R, 200/61.45 R-61.45 M, 307/91, 307/10.1, 307/119, 307/121, 73/1.37-1.39, 73/485, 73/514.01, 73/514.16, 73/514.29, 73/514.35, 73/514.36, 73/514.38
• US Class Current: 200/61.53
• CPC Class Codes: H01H 35/14 Switches operated by change of acceleration, e.g. by shock or vibration, inertia switch wherein the liquid constitutes a contact of the switch H01H29/002

Abstract

A side-impact electro-mechanical accelerometer is used in a vehicle to selectively actuate a vehicular safety device such as an airbag when a lateral acceleration force greater than a predetermined threshold level is sensed. A hollow housing is configured to retain an actuator element movable between a first, second and third position at least partially disposed therein when in the first position and a switch assembly including a first flexible conductive switch element movable between a first, second and third position disposed to engage and normally retain the actuator element when in the first position, a second conductive switch element disposed in spaced relationship relative to the actuator element and the first flexible conductive switch element when each is in the first position to engage the first flexible conductive switch element when the actuator element moves from the first position to the second position when the lateral acceleration force greater than a first predetermined threshold level is exerted on the side-impact electro-mechanical accelerometer to close a first electric circuit and a third flexible conductive switch element disposed in spaced relationship relative to the actuator element and the first and second flexible conductive switch elements when each is in the first or second positions to engage the second flexible conductive switch element when the actuator element moves from the first position to the third position when the lateral acceleration force greater than a second predetermined threshold level is exerted on the side-impact electro-mechanical accelerometer to close a second electric circuit.

Claims

1. A side-impact electro-mechanical accelerometer for use in a vehicle to close a first electric circuit when a lateral acceleration force greater than a first predetermined threshold level is sensed and to close a second electric circuit when a lateral acceleration force greater than a second predetermined threshold level is sensed, comprising:

a hollow housing having an actuator means including a member having an aperture formed therein to selectively receive an actuator therein;

a chamber cooperatively formed by said hollow housing and said member wherein said actuator means is selectively operable in a first, second and third actuator configuration such that said actuator is at least partially disposed in said housing when in said first actuator; and

a switch means including a first conductive switch element movable between a first, second and third position disposed to engage said actuator in a first configuration, a second conductive switch element movable between a first, second and third position disposed in spaced relationship relative to said actuator means and said first conductive switch element in said first configuration and disposed to engage said first conductive switch element in a second configuration when a lateral acceleration force greater than the first predetermined threshold level is exerted on the side-impact electro-mechanical accelerometer to close said first electric circuit and a third conductive switch element movable between a first and second position disposed in spaced relationship relative to the second conductive switch element in said first configuration and disposed to engage the second conductive switch element in said second configuration when a lateral acceleration force greater than the second predetermined threshold level is exerted on the electro-mechanical accelerometer to close said second electric circuit.

2. The side-impact electro-mechanical accelerometer of claim 1 wherein said member includes a recess formed therein to house said actuator means comprising an actuator damping means with said aperture formed therethrough to operatively retain said actuator therein when in said first configuration.

3. The side-impact electro-mechanical accelerometer of claim 2 wherein said actuator means further comprises an actuator adjustment means to longitudinally adjust the position of said actuator within said member when said actuator is in said first configuration.

4. The side-impact electro-mechanical accelerometer of claim 3 wherein said actuator adjustment means comprises an actuator seat member to engage said actuator when in said first configuration.

5. The side-impact electro-mechanical accelerometer of claim 4 wherein the actuator seat member includes a concave seat which engages the actuator when in said first configuration.

6. The side-impact electro-mechanical accelerometer of claim 2 wherein said member is substantially tubular and comprises an inner end portion having said recess formed therein to retain said actuator damping means therein and an outer end portion having a substantially cylindrical channel formed therein to retain said actuator adjustment means therein.

7. The side-impact electro-mechanical accelerometer of claim 6 wherein said actuator damping means comprises a substantially annular damping member securely disposed within said recess of said inner end portion of said substantially tubular member.

8. The side-impact electro-mechanical accelerometer of claim 1 wherein said actuator comprises a substantially spherical member movable between a first, second and third position having a diameter substantially equal to that of said aperture to minimize oscillation or lateral movement of said actuator within said aperture.

9. The side-impact electro-mechanical accelerometer of claim 1 wherein said chamber has a diameter greater than a diameter of said aperture of said member.

10. The side-impact electro-mechanical accelerometer of claim 9 wherein said member is misaligned, along a longitudinal axis thereof, with the center of said actuator when said actuator is in said second and third configurations.

11. The side-impact electro-mechanical accelerometer of claim 1 further including a retention means to retain said actuator within said chamber for at least three milliseconds when said actuator is in said second and third configurations.

12. The side-impact electro-mechanical accelerometer of claim 11 wherein said retention means comprises a retention shoulder formed on said member to engage and momentarily retain said actuator within said chamber when said actuator is in said second and third configurations.

13. The side-impact electro-mechanical accelerometer of claim 11 wherein said first conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section is configured to guide said actuator into said chamber when moving from said first position to said second and third positions.

14. The side-impact electro-mechanical accelerometer of claim 13 wherein said distal conductive section of said first conductive switch element includes a substantially concave end section.

15. The side-impact electro-mechanical accelerometer of claim 14 wherein said distal conductive section of said first conductive switch element includes a contact section to normally bias said actuator in said first configuration and terminates in a substantially concave end section.

16. The side-impact electro-mechanical accelerometer of claim 15 wherein said substantially concave end section engages said second conductive switch element when said actuator means is in said second configuration and said first conductive switch element is in said second position to complete said first electric circuit.

17. The side-impact electro-mechanical accelerometer of claim 15 wherein said distal conductive section of said second conductive switch element engages said third conductive switch element when said actuator means is in said third configuration and said second conductive switch element is in said third position to complete said second electric circuit.

18. The side-impact electro-mechanical accelerometer of claim 13 wherein said second conductive switch element includes a proximal conductive section and a distal conductive section and said member includes a first stop to engage said distal conductive section of said second conductive switch element when in said first position.

19. The side-impact electro-mechanical accelerometer of claim 13 wherein said third conductive switch element includes a proximal conductive section and a distal conductive section and said member includes a second stop to engage said distal conductive section of said third conductive switch element when in said first position.

20. The side-impact electro-mechanical accelerometer of claim 1 wherein said first conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section includes an end section to momentarily retain said actuator in said chamber when said actuator is said second and third configurations.

21. The side-impact electro-mechanical accelerometer of claim 20 wherein said end section of said distal conductive section of said first conductive switch element is substantially concave.

22. The side-impact electro-mechanical accelerometer of claim 21 wherein said substantially concave end section of said first conductive switch element engages said second conductive switch element when said actuator means is in a second configuration and said first conductive switch element is in said second position to complete said first electric circuit.

23. The side-impact electro-mechanical accelerometer of claim 1 wherein said first conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section includes a contact section to normally bias said actuator in said first configuration.

24. The side-impact electro-mechanical accelerometer of claim 23 wherein said second conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section engages said third conductive switch element when said second conductive switch element is in said third position and said third conductive switch position is in said second position to complete said second electric circuit.

25. The side-impact electro-mechanical accelerometer of claim 1 wherein said first conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section includes a substantially concave end section to momentarily retain said actuator in said chamber when moving from said first configuration to said second and third configurations, said second conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section engages said first conductive switch element when said second conductive switch element is in said second position and said third conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section engages said second conductive switch element when said third conductive switch element is in said second position.

26. The side-impact electro-mechanical accelerometer of claim 25 wherein said member includes a first stop to engage said distal conductive section of said second conductive switch element when in said first position.

27. The side-impact electro-mechanical accelerometer of claim 26 wherein said member includes a second stop to engage said distal conductive section of said third conductive switch element when in said first position.

28. A side-impact electro-mechanical accelerometer for use in a vehicle to close a first electric circuit when a lateral acceleration force greater than a first predetermined threshold level is sensed and to close a second electric circuit when a lateral acceleration force greater than a second predetermined threshold level is sensed comprising a hollow housing having an actuator means including an actuator and a track guiding means having a body with a recess formed therein to selectively receive said actuator therein;

a chamber cooperatively formed by said hollow housing and said body wherein said actuator means is selectively operable in a first, second and third actuator configuration when said actuator is in a first, second and third position, respectively, such that said actuator is at least partially disposed in said housing when in said first position; and

a switch means including a first conductive switch element movable between a first, second and third position disposed to engage said actuator in said first position, a second conductive switch element movable between a first, second and third position disposed in spaced relationship relative to said actuator means and said first conductive switch element in said first position and disposed to engage said first conductive switch element in said second position when the lateral acceleration force greater than the first predetermined threshold level is exerted on the side-impact electro-mechanical accelerometer to close said first electric circuit and a third conductive switch element movable between a first and second position disposed in spaced relationship relative to the second conductive switch element in said first position and to engage the second conductive switch element in said second position when a lateral acceleration force greater than the second predetermined threshold level is exerted on the electro-mechanical accelerometer to close said second electric circuit.

29. The side-impact electro-mechanical accelerometer of claim 28 wherein said track guiding means includes a track to guide said actuator between said first position and said second and third positions.

30. The side-impact electro-mechanical accelerometer of claim 29 wherein said track includes a substantially vertical seat to engage said actuator when in said first position and a travel aperture to receive at least a portion of said actuator when in said second position.

31. The side-impact electro-mechanical accelerometer of claim 30 wherein said actuator comprises a substantially spherical member movable between a first, second and third position having a diameter substantially equal in diameter to that of said travel aperture to minimize oscillation or lateral movement of said actuator while retained by said track.

32. The side-impact electro-mechanical accelerometer of claim 30 wherein said chamber has a diameter greater in diameter to that of said travel aperture of said track.

33. The side-impact electro-mechanical accelerometer of claim 32 wherein the aperture of said track is misaligned, along a longitudinal axis thereof, with the center of said actuator when said actuator is in said second and third positions.

34. The side-impact electro-mechanical accelerometer of claim 28 wherein said body comprises an inner end portion having said recess formed therein to retain said track guiding means therein.

35. The side-impact electro-mechanical accelerometer of claim 28 further including a retention means to retain said actuator within said chamber for at least three milliseconds when said actuator is in said second and third positions.

36. The side-impact electro-mechanical accelerometer of claim 35 wherein said retention means comprises a retention shoulder formed on said body to engage and momentarily retain said actuator within said chamber when said actuator is in said second and third positions.

37. The side-impact electro-mechanical accelerometer of claim 35 wherein said first conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section is configured to guide said actuator into said chamber when moving from said first position to said second and third positions.

38. The side-impact electro-mechanical accelerometer of claim 37 wherein said distal conductive section of said first conductive switch element includes a substantially concave end section.

39. The side-impact electro-mechanical accelerometer of claim 38 wherein said distal conductive section of said first conductive switch element includes a contact section to normally bias said actuator in said first position and terminates in a substantially concave end section.

40. The side-impact electro-mechanical accelerometer of claim 39 wherein said substantially concave end section of said first conductive switch element engages said second conductive switch element when said actuator and said first conductive switch element are each in said second position to complete said first electric circuit.

41. The side-impact electro-mechanical accelerometer of claim 39 wherein said second conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section engages said third conductive switch element when said second conductive switch element is in said third position to complete said second electric circuit.

42. The side-impact electro-mechanical accelerometer of claim 37 wherein said second conductive switch element includes a proximal conductive section and a distal conductive section and said body includes a first stop to engage said distal conductive section of said second conductive switch element when in said first position.

43. The side-impact electro-mechanical accelerometer of claim 42 wherein said third conductive switch element includes a proximal conductive section and a distal conductive section and said body includes a second stop to engage said distal conductive section of said third conductive switch element when in said first position.

44. The side-impact electro-mechanical accelerometer of claim 28 wherein said first conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section includes an end section to momentarily retain said actuator in said chamber when said actuator is said second and third positions.

45. The side-impact electro-mechanical accelerometer of claim 44 wherein said end section of said distal conductive section of said first conductive switch element is substantially concave.

46. The side-impact electro-mechanical accelerometer of claim 45 wherein said substantially concave end section of said first conductive switch element engages said second conductive switch element when said actuator and said first conductive switch element are each in said second position to complete said second electric circuit.

47. The side-impact electro-mechanical accelerometer of claim 46 wherein said second conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section engages said third conductive switch element when said second conductive switch element is in said third position and said third conductive switch position is in said second position to complete said second electric circuit.

48. The side-impact electro-mechanical accelerometer of claim 28 wherein said first conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section includes a contact section to normally bias said actuator in said first position.

49. The side-impact electro-mechanical accelerometer of claim 28 wherein said first conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section includes a substantially concave end section to momentarily retain said actuator in said chamber when moving from said first position to said second and third positions, said second conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section engages said first conductive switch element when said second conductive switch element is in said second position and said third conductive switch element includes a proximal conductive section and a distal conductive section wherein said distal conductive section engages said second conductive switch element when said third conductive switch element is in said second position.

50. The side-impact electro-mechanical accelerometer of claim 49 wherein said body includes a first stop to engage said distal conductive section of said second conductive switch element when in said first position.

51. The side-impact electro-mechanical accelerometer of claim 50 wherein said body includes a second stop to engage said distal conductive section of said third conductive switch element when in said first position.