Electro-mechanical accelerometer to actuate a vehicular safety device

• US 5,845,730 A
• Filed: 12/31/1996
• Issued: 12/08/1998
• 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: Simpson, Leonard, Thuen, Torbjorn, Grossi, Carl Thomas III
• Primary Examiner(s): English, Peter C.
• Application Number:
  US08/777,851
• Time in Patent Office: 707 Days
• Field of Search: 180/282, 180/274, 280/735, 280/734, 200/61.53, 200/61.45 R
• US Class Current: 180/282
• 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
• CPC Class Codes: H01H 35/142 Damping means to avoid unwanted response

Abstract

An electro-mechanical accelerometer is disclosed for use in a vehicle to selectively actuate a vehicular safety device such as, for example, an airbag when a deceleration force greater than a predetermined threshold level is sensed.

Claims

1. An electro-mechanical accelerometer for use in a vehicle to selectively actuate at least a first vehicular safety device when a deceleration force greater than a first predetermined threshold level is sensed and to selectively actuate at least a second vehicular safety device when a deceleration 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 configuration and 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 a deceleration force greater than the first predetermined threshold level is exerted on the electro-mechanical accelerometer to transmit a signal operative to actuate the at least a first vehicular safety device 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 deceleration force greater than the second predetermined threshold level is exerted on the electro-mechanical accelerometer to transmit a signal operative to actuate the at least a second vehicular safety device.

2. The electro-mechanical accelerometer of claim 1 wherein said member includes a recess formed therein to house an actuator damping means operative to retain said actuator therein when in said first configuration.

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

4. The 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 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 electro-mechanical accelerometer of claim 3 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 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 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 the diameter of said aperture to minimize oscillation or lateral movement of said actuator within said aperture.

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

10. The electro-mechanical accelerometer of claim 9 wherein the longitudinal axis of said aperture of said member is misaligned with the center of said actuator when said actuator is in said second and third configurations.

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

12. The 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 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 configuration to said second and third configurations.

14. The electro-mechanical accelerometer of claim 13 wherein said distal conductive section is substantially concave.

15. The electro-mechanical accelerometer of claim 14 wherein said distal conductive section of said first conductive switch element terminates in a convex contact element to normally bias said actuator in said first configuration.

16. The electro-mechanical accelerometer of claim 15 wherein said convex contact element engages said second conductive switch element when said actuator is in said second configuration and said first conductive switch element is in said second position to complete an electrical circuit between a power source and the at least a first vehicular safety device to actuate the at least a first vehicular safety device.

17. The electro-mechanical accelerometer of claim 15 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 an electric circuit between a power source and the at least a second vehicular safety device to actuate the at least a second vehicular safety device.

18. The 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 stop to engage said distal conductive section of said second conductive switch element when in said first position.

19. The electro-mechanical accelerometer of claim 13 wherein said third conductive switch element includes a proximal conductive section and a distal conductive section.

20. The 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 is configured to guide said actuator into said chamber when said actuator is moving from said first configuration to said second and third configurations.

21. The electro-mechanical accelerometer of claim 20 wherein said distal conductive section is substantially concave.

22. The 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 terminates in a convex contact element to normally bias said actuator in said first configuration.

23. The electro-mechanical accelerometer of claim 22 wherein said convex contact element engages said second conductive switch element when said actuator is in said second configuration and said first conductive switch element is in said second position to complete an electrical circuit between a power source and the at least a first vehicular safety device to actuate the at least a first vehicular safety device.

24. The electro-mechanical accelerometer of claim 22 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 element is in said second position to complete an electrical circuit between a power source and the at least a second vehicular safety device to actuate the at least a second vehicular safety device.

25. The 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 is configured to guide said actuator into 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 electro-mechanical accelerometer of claim 25 wherein said member includes a stop to engage said distal conductive section of said second conductive switch element when in said first position.