Spring mass passenger compartment crash sensors

• US 5,233,141 A
• Filed: 07/09/1991
• Issued: 08/03/1993
• Est. Priority Date: 02/23/1989
• Status: Expired due to Term

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Automotive Technologies International Incorporated
• Inventors: Breed, David S.
• Primary Examiner(s): SCOTT, JAMES R
• Application Number:
  US07/727,757
• Time in Patent Office: 756 Days
• Field of Search: 200/61.45 R-61.53, 307/121
• US Class Current: 200/61.45R
• CPC Class Codes: B60R 2021/0006 Lateral collision
• CPC Class Codes: B60R 2021/01006 Mounting of electrical components in vehicles
• CPC Class Codes: B60R 21/01 Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents electrical circuits for transmission of signals between steering wheel and the vehicle itself B60R16/027; for electrically actuating belt retractor locking means B60R22/343
• 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: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558
• CPC Class Codes: B60R 21/33 Arrangements for non-electric triggering of inflation electrical circuits for triggering safety arrangements B60R21/01
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends
• 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 35/141 Details
• CPC Class Codes: H01H 35/142 Damping means to avoid unwanted response

Abstract

This invention includes crash sensors designed to be used for frontal impact sensing and the strategies of using these sensors. It is analyzed and shown that for cases where the passenger compartment mounted discriminating sensor is used as a backup to forward crush zone mounted crash sensors or where the vehicle occupant is wearing a seat belt, that spring mass sensors can be used. In addition, spring mass sensors can also be used as arming or safing sensors. In all cases, provision must be made to minimize the effects of cross-axis vibrations on such sensors as taught by this invention. Such sensors can be made with housings of plastic. A preferred embodiment of this invention utilizes a mass supported and biased by a beam contact which is attached to a housing. These sensors are useful for sensing frontal impacts in the passenger compartment both as primary sensors and as single or dual contact arming sensors. They can also be combined by placing two sensors within a single housing and, in some cases, the same mass can be used for both sensors. Finally, they can be used in electro-mechanical and in all mechanical air bag systems. It is further taught that the response of all spring biased sensors can be improved by making the at rest bias substantially less than the bias at actuation.

Claims

1. A spring mass crash sensor for mounting in the passenger compartment comprising:

(1) a housing;

(2) a mass in said housing having one end rotatably attached to said housing thereby forming a rotatable attachment;

(3) means to support said mass in said housing, said support means providing a substantially greater resistance to vertical and lateral forces than to longitudinal forces on said mass;

(4) a first contact means;

(5) a biasing means for biasing said mass toward a first position in said housing;

(6) a second contact means acting in cooperation with said first contact means for closing an electrical circuit when said mass moves to a second position in said housing.

2. The invention according to claim 1 wherein said first contact means is cantilevered from said housing.

3. The invention according to claim 1 wherein said second contact means is cantilevered from said housing.

4. The invention in accordance with claim 1, wherein said first contact means is formed from a metal strip and has a width which is much larger in dimension then its thickness.

5. The invention in accordance with claim 1, wherein said contact means and said housing are attached by insert molding.

6. The invention in accordance with claim 1, wherein said contact means are made of metal and molded into said housing.

7. The invention in accordance with claim 1, wherein said first contact means provides said biasing force.

8. The invention in accordance with claim 1, wherein said biasing means comprises a spring.

9. The invention in accordance with claim 1, wherein said first and second contact means are combined with said housing in a molding process.

10. The invention in accordance with claim 9, wherein said contact means are treated to become adhesive to plastic so as to prevent separation between said contact means and said housing within the operating temperature range of said sensor.

11. The invention in accordance with claim 10, wherein said treatment provides hermetical sealing to said sensor.

12. The invention in accordance with claim 1, wherein means are provided to hermetically seal the sensor.

13. The invention in accordance with claim 1, wherein said contact means are coated with a dampening material to reduce vibrations.

14. The invention in accordance with claim 1 wherein the biasing force at the first position is less than half of the biasing force at the second position.

15. The invention in accordance with claim 1, wherein said rotatable attachment comprises a hinge.

16. A system for triggering a passive occupant restraint device for a motor vehicle having a crush zone in the forward region thereof, said system comprising in combination:

(a) at least two discriminating sensors disposed in said vehicle crush zone;

(b) a discriminating sensor disposed in said vehicle remote from said crush zone;

(c) an arming sensor disposed in said vehicle remote from said crush zone; and

(d) means, responsive to said sensors, for triggering a passive occupant restraint system in said vehicle when one of said discriminating sensors and said arming sensor indicate an incipient vehicle crash;

wherein at least one sensor comprises;

(1) a housing;

(2) a mass in said housing;

(3) means to support said mass in said housing, said support means providing a substantially greater resistance to vertical and lateral forces than to longitudinal forces on said mass;

(4) a first contact means;

(5) a biasing means for biasing said mass toward a first position in said housing,

(6) a second contact means acting in cooperation with said first contact means for closing an electrical circuit when said mass moves to a second position in said housing.

17. The invention in accordance with claim 16, wherein at least one of said crush zone mounted sensor is a crush switch.

18. The invention in accordance with claim 16 wherein said sensor system comprises two crush zone mounted crush switch sensors, a non-crush zone mounted arming sensor and a noncrush zone mounted discriminating sensor.