Seat belt tension sensor

• US 20070240525A1
• Filed: 06/14/2007
• Published: 10/18/2007
• Est. Priority Date: 06/19/2001
• Status: Active Grant

• Current Assignee: CTS Corporation
• Original Assignee: CTS Corporation
• Inventors: Kaijala, Murray
• Granted Patent: US 7,373,845 B2
• Time in Patent Office: Days
• US Class Current: 73/862.391
• CPC Class Codes: B60R 21/0155 sensing belt tension
• CPC Class Codes: B60R 22/18 Anchoring devices
• CPC Class Codes: G01L 1/22 using resistance strain gauges

Abstract

A seat belt tension sensor for use with a seat belt assembly. The sensor includes a housing that has a slot and a plate coupled with the housing. The plate has another slot and a cutout. The slots are connected with a seat belt. A sensor is retained by the housing and extends into the cutout. A portion of the plate is adapted to be engaged by the sensor as tension is increased on the seat belt. The sensor generates an electrical signal that is indicative of seat belt tension.

Claims

1. A seat belt tension sensor comprising:

a housing having a first slot;

a plate coupled with the housing, the plate having a second slot and a cutout, the first and second slots being adapted to be connected with a seat belt;

a sensor retained by the housing and extending into the cutout, a first portion of the plate being adapted be engaged by the sensor as tension is increased on the seat belt, the sensor being adapted to generate an electrical signal that is indicative of seat belt tension.

2. The seat belt tension sensor according to claim 1 wherein the plate is fixed and the housing moves relative to the housing.

3. The seat belt tension sensor according to claim 1 wherein movement of the housing relative to the plate is limited by engagement of a portion of the housing with a second portion of the plate.

4. The seat belt tension sensor according to claim 1 wherein the sensor is a strain sensitive resistor.

5. The seat belt tension sensor according to claim 1 wherein the sensor is mounted to a printed circuit board.

6. The seat belt tension sensor according to claim 5 wherein a wire harness is connected to the printed circuit board.

7. The seat belt tension sensor according to claim 5 wherein a signal conditioning circuit is mounted on the printed circuit board.

8. The seat belt tension sensor according to claim 1 wherein the plate is fixed to a vehicle.

9. A tension sensor comprising:

a housing having a first slot;

a plate having a first end and a second end, the first end located in the housing and the second end extending from the housing;

a second slot located in the plate, the first and second slots being adapted to be connected with a seat belt;

a cutout located in the plate; and

a sensor retained by the housing and extending into the cutout, the sensor pressing on a first portion of the plate as tension is increased on the seat belt, the sensor being adapted to generate an electrical signal that is indicative of tension in the seat belt.

10. The tension sensor according to claim 9 wherein the plate is fixed and the housing moves relative to the housing.

11. The tension sensor according to claim 9 wherein movement of the housing relative to the plate is limited by engagement of a portion of the housing with a second portion of the plate.

12. The tension sensor according to claim 9 wherein the sensor is a strain sensitive resistor.

13. The tension sensor according to claim 9 wherein the housing has a pair of posts, the sensor being retained by the posts.

14. The tension sensor according to claim 9 wherein a spring carriage is coupled to the sensor.

15. The tension sensor according to claim 9 wherein the plate is fixed to a vehicle.

16. A seat belt tension sensor comprising:

housing means for containing the seat belt tension sensor, the housing means configured to be coupled with a seat belt;

;

plate means for transferring tension from the seat belt to a vehicle structure, the plate means coupled with the housing means; and

sensor means for measuring the amount of tension in the seat belt, the sensor means being coupled to the housing means, the sensor means configured to generate an electrical signal that is indicative of the amount of seat belt tension,

the plate means cooperating with the housing means to form protection means for limiting the maximum force applied to the sensor means.

17. The seat belt tension sensor according to claim 16 wherein the sensor means further comprises:

a substrate;

at least one strain sensitive resistor mounted on the substrate; and

an actuator mounted over the resistor.

18. The seat belt tension sensor according to claim 17 wherein the actuator contacts the plate means.

19. The seat belt tension sensor according to claim 16 wherein the plate means further comprises:

a plate having a slot, a cutout and an aperture.

20. The seat belt tension sensor according to claim 19 wherein a projection extends into the cutout.

21. The seat belt tension sensor according to claim 16 wherein spring means are coupled to the sensor means.