Seat belt tension sensor

• US 7,347,108 B2
• Filed: 09/26/2005
• Issued: 03/25/2008
• Est. Priority Date: 06/19/2001
• Status: Expired due to Fees

• Current Assignee: CTS Corporation
• Original Assignee: CTS Corporation
• Inventors: Kaijala, Murray
• Primary Examiner(s): Lefkowitz; Edward
• Assistant Examiner(s): Kirkland, III; Freddie
• Application Number:
  US11/235,414
• Publication Number:
  US 20060021452A1
• Time in Patent Office: 911 Days
• Field of Search: 738/623.91, 738/623.93
• US Class Current: 73/862.393
• CPC Class Codes: B60R 21/0155 sensing belt tension
• CPC Class Codes: B60R 22/18 Anchoring devices

Abstract

A seat belt tension sensor for measuring the amount of tension in a vehicle seat belt. The seat belt tension sensor has a housing and an anchor plate that is mounted in the housing. The housing moves relative to the anchor plate. A magnet is held by the anchor plate. A sensor is mounted to the housing. The sensor generates an electrical signal in response to relative movement between the housing and the anchor plate. The electrical signal changes in proportion to the amount of tension on the seat belt. A spring is mounted in association with the housing and the anchor plate. The spring biases the housing from the anchor plate. An integral connector extends from the housing.

Claims

1. A seat belt tension sensor for attachment between a seat belt and a vehicle structure comprising:

a) a housing;

b) an anchor plate at least partially mounted in the housing, the housing and the anchor plate being movable relative to each other, the anchor plate having a cutout and a projection extending into the cutout;

c) a magnet retained by the anchor plate in the cutout;

d) a sensor mounted to the housing, the sensor generating an electrical signal in response to relative movement between the housing and the anchor plate, the electrical signal changing in proportion to the amount of tension on the seat belt; and

e) a spring mounted in association with the housing and the anchor plate, the spring biasing the housing from the anchor plate.

2. The seat belt tension sensor according to claim 1, wherein the anchor plate is in a fixed position and the housing is moveable.

3. The seat belt tension sensor according to claim 1, wherein the magnet is in a fixed position and the sensor moves.

4. The seat belt tension sensor according to claim 1, wherein the magnet is mounted in a magnet carrier, the magnet carrier located in the cutout.

5. The seat belt tension sensor according to claim 4, wherein the magnet carrier has a slot and a cavity, the magnet mounted in the cavity.

6. The seat belt tension sensor according to claim 5, wherein the housing has a rail, the rail being mounted in the slot, the rail further sliding in the slot.

7. The seat belt tension sensor according to claim 1, wherein the anchor plate has a first and second aperture, the cutout located between the apertures.

8. The seat belt tension sensor according to claim 7, wherein the seat belt passes through the first aperture.

9. The seat belt tension sensor according to claim 7, wherein the housing has an apertured flange, the flange extending into the first aperture.

10. The seat belt tension sensor according to claim 1, wherein a connector is attached to the housing.

11. The seat belt tension sensor according to claim 10, wherein at least one terminal is mounted in the housing and extends between the sensor and the connector.

12. A seat belt tension sensor comprising:

a) housing means;

b) plate means at least partially mounted in the housing means, the housing means to and the plate means being movable relative to each other;

the plate means having a cutout and a projection into the cutout;

c) flux generating means for generating a flux field, the flux generating means connected with the plate means;

d) sensor means for sensing the flux field, the sensor means connected to the housing means, the sensor means generating an electrical signal in response to relative movement between the housing means and the plate means, the electrical signal changing in proportion to the amount of tension on a seat belt; and

e) biasing means mounted in association with housing means and the plate means for biasing the housing means from the plate means.

13. A seat belt tension sensor for attachment with a seat belt comprising:

a) a housing;

b) an anchor plate at least partially mounted in the housing, the housing being movable between a first and a second position, the anchor plate having a cutout and a projection extending into the cutout;

c) a magnet held by the anchor plate;

d) a sensor mounted to the housing, the sensor juxtaposed to the magnet; and

e) a spring mounted between the anchor plate and the housing, the spring being compressed as the housing moves away from the first position.

14. The seat belt tension sensor according to claim 13, wherein the anchor plate and the housing together limit the maximum tension.

15. The seat belt tension sensor according to claim 13, wherein the housing has a spring channel, the spring at least partially mounted in the spring channel.

16. The seat belt tension sensor according to claim 13, wherein the housing has an integral connector.

17. The seat belt tension sensor according to claim 13, wherein the sensor slides by the magnet.

18. The seat belt tension sensor according to claim 13, wherein a spring carriage is mounted with the anchor plate.

19. The seat belt tension sensor according to claim 13, wherein the magnet is mounted in a magnet carrier.

20. The seat belt tension sensor according to claim 19, wherein the magnet carrier slides on a rail.

21. The seat belt tension sensor according to claim 20, wherein the magnet carrier has a slot, the slot being engaged with the rail.