Acceleration change sensor

• US 3,967,135 A
• Filed: 04/11/1974
• Issued: 06/29/1976
• Est. Priority Date: 04/11/1974
• Status: Expired due to Term

• Current Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Balban, Morton S., Larson, Doublas A.
• Primary Examiner(s): Hohauser, Herman
• Application Number:
  US05/460,009
• Time in Patent Office: 810 Days
• Field of Search: 73/517 R, 73/514, 73/71.1, 73/71.3, 250/231, 250/229, 250/232, 340/52 H, 340/262, 307/10 R, 307/121
• US Class Current: 307/121
• CPC Class Codes: B60R 2021/01322 comprising variable thresholds, e.g. depending from other collision parameters
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: G01P 15/0891 with indication of predetermined acceleration values G01P15/135 takes precedence
• CPC Class Codes: G01P 15/093 by photoelectric pick-up

Abstract

A device is provided for indicating the occurrence of rate of change of velocity of a body equal to or in excess of a predetermined value. An inertial mass is yieldably biased toward a reference position, but moves to a second position when the body is subjected to rates of change of velocity in excess of the predetermined value. A light source is provided, and when the inertial mass is in its reference position, a first light responsive means is out of light communication with the source, while a second light responsive means receives light from the light source. When the inertial mass is in its second position, the first light responsive means receives light from the light source and the second light responsive means is out of light communication with the source. Upon receipt of light, the first light responsive means produces an electric signal, but the second light responsive means no longer produces a signal. In response thereto, the signal sensor logic circuit then provides a signal to actuate an indicating circuit or the firing circuit of a device such as a vehicle occupant restraint system.

Claims

1. A device for indicating the occurrence of rates of change of velocity of a body, equal to and greater than a predetermined minimum, comprising:

a. a base fixed to the body;

b. an inertial mass movable with respect to said base and having a reference position, and means biasing said mass to said reference position, said mass being movable to overcome the biasing force and move to a second position when the body is subjected to rates of change of velocity equal to and greater than the predetermined minimum;

c. a light source attached to said base;

d. a first light responsive means attached to said base and disposed to be out of light communication with said light source when said mass is in said reference position and to receive light from said light source when said mass is in said second position;

e. a second light responsive means attached to said base disposed to be out of light communication with said light source when said mass is in said second position and to receive light from said light source when said mass is in said reference position; and

f. electric circuit means connected to said first and second light responsive means operative to indicate the status of both said first and second light responsive means.

2. The device defined in claim 1 wherein said means biasing said inertial mass includes a band of resilient metal wrapped about the periphery of said mass.

3. The device defined in claim 1 wherein:

a. said mass has a generally cylindrical configuration; and

b. said biasing means includes a flexible, resilient band having one end anchored to said base and passing around at least a portion of said mass.

4. The device defined in claim 3 wherein said band passes around substantially the entire periphery of said mass and has the opposite end anchored to said base.

5. The device defined in claim 4 wherein said band includes an elongated slot formed therein adjacent said one end and an elongated tongue formed therein adjacent said opposite end, said tongue having a width less than the width of said slot and less than the difference between the width of said band and the width of said slot.

6. The device defined in claim 1 wherein said biasing means prevents said mass from moving to said second position at rates of change of velocity less than about 1.0 g.

7. The device defined in claim 1 wherein:

a. a first light source is in light communication with said first light responsive means when said mass is in said second position; and

b. a second light source is in light communication with said second light responsive means when said mass is in said reference position.

8. The device defined in claim 7 wherein said first and second light responsive means provide a diagnostic electric signal, when said mass is in said reference position, to indicate that said first light source and said first light responsive means are operable.

9. The device defined in claim 1 wherein said light source includes a plurality of spaced directional light emitters.

10. The device defined in claim 9 wherein said light emitters comprise a pair of spaced light-emitting diodes and said first and second light responsive means comprise phototransistors.

11. The device of claim 1 wherein said electric circuit means includes logic means having:

a. means for providing a first predetermined output signal only when said first light responsive means is receiving light and said second light responsive means is out of light communication with said light source; and

b. means for providing a second predetermined output signal only when said second light responsive means is receiving light and said first light responsive means is out of light communication with said light source.

12. A collision sensor for providing a first output signal to a firing circuit and a second output signal to a diagnostic circuit of a vehicle occupant restraint system, comprising:

a. a housing;

b. first and second light emitters disposed within said housing;

c. first and second light responsive means connected electrically, said first light responsive means being disposed to receive light from said first light emitter and said second light responsive means being disposed to receive light from said second light emitter;

d. an inertial member having a normal position preventing light communication between said first light emitter and said first light responsive means and actuating position preventing light communication between said second light emitter and said second light responsive means;

e. a flexible band having a first end anchored adjacent said first light emitter and a second end anchored adjacent said second light emitter, said band passing around substantially the entire periphery of said inertial member, maintaining said member in said normal position at vehicle accelerations less than a predetermined acceleration force; and

f. logic means connected electrically to said first and second light responsive means operable to indicate the status of both said first and second light responsive means.

13. The sensor of claim 12 wherein said logic means includes:

a. means for providing said first output signal only when said first light responsive means is receiving light and said second light responsive means is out of light communication with said second light emitter; and

b. means for providing said second output signal only when said second light responsive means is receiving light and said first light responsive means is out of light communication with said first light emitter.

14. The sensor of claim 12 wherein said first and second light emitters comprise light-emitting diodes and said first and second light responsive means comprise phototransistors.

15. The sensor of claim 12 wherein said inertial member has a cylindrical configuration and is oriented for rolling movement in a direction generally perpendicular to the path of light received by said first light responsive means.

16. A vehicle collision sensor for providing a signal to a firing circuit of an occupant restraint system when the vehicl is subjected to accelerations greater than a predetermined minimum comprising:

a. a light source;

b. a first light responsive means positioned for light communication with said light source;

c. an inertial mass including light directing means having a first position between said light source and said first light responsive means to prevent light communication therebetween when the vehicle is subjected to less than the predetermined acceleration force;

d. means yieldably urging said inertial mass to said first position of said light directing means; and

e. a second light responsive means adjacent said light source, said light directing means including means operable to direct light from said light source to said second light responsive means when said light directing means is in said first position, such that when the vehicle is subjected to at least the predetermined acceleration force, said light directing means moves from said first position to a second position and light is permitted to pass from said light source to said first light responsive means.

17. The device defined in claim 16 wherein said light directing means includes a light reflecting surface thereon.

18. The sensor defined in claim 16 wherein said light source, said first light responsive means and said second light responsive means are disposed such that the movement of said light directing means to a position intermediate said first and second positions prevents light communication between said light source and said first light responsive means, and prevents direction of light from said light source to said second light responsive means.

19. The sensor defined in claim 17 wherein said light directing member is generally cylindrical and said light reflecting surface comprises and indented surface in the circular end wall of said member.

20. The sensor defined in claim 19 wherein said indented surface has a generally concave configuration.