Airbag deployment controller

• US 5,865,463 A
• Filed: 04/02/1997
• Issued: 02/02/1999
• Est. Priority Date: 02/15/1997
• 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: Nakhla, Said Shafik, Griggs, James Woodhouse III, Gagnon, Scott Darrell, Boyd, Clinton
• Primary Examiner(s): Rice, Kenneth R.
• Application Number:
  US08/831,238
• Time in Patent Office: 671 Days
• Field of Search: 280/735, 280/730.2
• US Class Current: 280/735
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60N 2/58 Seat coverings
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/0152 using strain gauges
• CPC Class Codes: G01G 19/4142 for controlling activation of safety devices, e.g. airbag systems electrical circuits for triggering safety arrangements in case of vehicle accidents B60R21/015

Abstract

An airbag deployment controller has a plurality of sensors interposed between a rigid member and a seat pan member such that the weight supported by a portion of the seat cushion which the rigid member underlies is transferred from the rigid member to the seat pan via said sensors. The sensors sense the magnitude of the force transferred therethrough. A device processes signals from the sensors to determine the weight that the portion of the seat cushion which the rigid member underlies is bearing. The signal processing device controls the activation and operation of an airbag as a function of the presence and weight of a seat occupant. Optionally, the tension on a seat belt may also be sensed and processed as a parameter for controlling the deployment of an airbag.

Claims

1. An airbag deployment controller comprising:

(a) a seat force sensing assembly comprising;

(i) a seat pan,

(ii) a rigid member disposed vertically above said seat pan in a spaced apart vertically juxtaposed relationship with said seat pan, said rigid member underlying a portion of a seat cushion, and

(iii) a plurality of sensors interposed between the rigid member and the seat pan such that all of the force transferred from the rigid member to the seat pan is transferred via said sensors which sense the magnitude of the force transferred therethrough and generate signals; and

(b) a signal processor which is in circuit communication with said sensors and comprises

(i) signal summing circuitry;

(ii) comparator circuitry; and

(iii) a switch through which an airbag firing signal must pass, with each component of the signal processor being in circuit communication with another component of the signal processor.

2. An airbag deployment controller according to claim 1 wherein the rigid member of the seat force sensing assembly has a generally rectangular shape and a sensor is located in the vicinity of each corner of the rigid member.

3. An airbag deployment controller according to claim 1 wherein the signal processor further comprises signal amplifier circuitry which amplifies the output of the summing circuitry before the output of the summing circuitry is processed by the comparator circuitry.

4. An airbag deployment controller according to any of claims 1, 2 or 3 wherein at least one of said sensors is a strain gauge.

5. An airbag deployment controller according to any of claims 1, 2 or 3 wherein said at least one of said sensors is a load cell.

6. An airbag deployment controller according to any of claims 1, 2 or 3 wherein at least one of said sensors is a variable resistance pressure sensor.

7. An airbag deployment controller according to any of claims 1, 2 or 3 wherein at least one of said sensors is a variable capacitance pressure sensor.

8. An airbag deployment controller according to any of claims 1, 2 or 3 wherein at least one of said sensors is a variable inductance pressure sensor.

9. An airbag deployment controller according to claim 1 wherein the rigid member and the seat pan are at least partially retained in said vertically juxtaposed relationship by a tension member.

10. An airbag deployment controller according to claim 1 wherein said tension member is a sheet material overlying the seat cushion and secured to the seat pan.

11. An airbag deployment controller according to claim 1 further comprising means for sensing the tension on a seat belt and circuitry for processing a signal from said tension sensing means.

12. An airbag deployment controller comprising:

a. a seat force sensing assembly comprising

(i) a seat having a seat support member and a seat pan member fastened to one another;

(ii) a frame disposed vertically above said seat pan in a spaced apart vertically juxtaposed relationship with said seat pan, said frame underlying a portion of a seat cushion; and

(iii) a plurality of sensors interposed between the frame and the seat pan such that all of the force transferred from the frame to the seat pan is transferred via said sensors which sense the magnitude of the force transferred therethrough and send signals to a signal processor; and

b. a signal processor which is in circuit communication with said sensors and processes the signals from the sensors to determine the weight that said portion of the seat cushion is bearing, said signal processor comprising

(i) signal summing circuitry;

(ii) comparator circuitry; and

(iii) a switch through which an airbag firing signal must pass with each component of the signal processor being in circuit communication with another component of the signal processor.

13. An airbag deployment controller comprising:

a. a seat force sensing assembly comprising

(i) a seat having a seat support member and a seat pan member fastened to one another;

(ii) a frame disposed vertically above said seat pan in a spaced apart vertically juxtaposed relationship with said seat pan, said frame underlying a portion of a seat cushion, said portion of the seat cushion being spaced apart from a rear edge of the seat cushion; and

(iii) a plurality of sensors interposed between the frame and the seat pan such that all of the force transferred from the frame to the seat pan is transferred via said sensors which sense the magnitude of the force transferred therethrough and send signals to a device which processes said signals to a signal processor; and

b. a signal processor which is in circuit communication with said sensors and processes the signals from the sensors to determine the weight that said portion of the seat cushion is bearing, said signal processor comprising

(i) signal summing circuitry;

(ii) comparator circuitry; and

(iii) a switch through which an airbag firing signal must pass with each component of the signal processor being in circuit communication with another component of the signal processor.

14. An airbag deployment controller according to claim 13 wherein the frame has a generally rectangular shape and a sensor is located in the vicinity of each corner of the frame.

15. An airbag deployment controller comprising:

a. a seat force sensing assembly comprising

(i) a seat having a seat support member and a seat pan member fastened to one another;

(ii) a frame disposed vertically above said seat pan in a spaced apart vertically juxtaposed relationship with said seat pan, said frame underlying a portion of a seat cushion, the frame and the seat pan being at least partially retained in said vertically juxtaposed relationship by a tension member;

(iii) a plurality of sensors interposed between the frame and the seat pan such that all of the force transferred from the frame to the seat pan is transferred via said sensors which sense the magnitude of the force transferred therethrough and send signals to a signal processor; and

a. a signal processor which is in circuit communication with said sensors and processes the signals from the sensors to determine the weight that said portion of the seat cushion is bearing, said signal processor comprising

(i) signal summing circuitry;

(ii) comparator circuitry; and

(iii) a switch through which an airbag firing signal must pass with each component of the signal processor being in circuit communication with another component of the signal processor.

16. An airbag deployment controller according to claim 15 wherein said tension member is a sheet material overlying the seat cushion and secured to the seat pan.

17. An airbag deployment controller according to either of claims 15 or 16 wherein at least one of said sensors is a strain gauge.

18. An airbag deployment controller according to either of claims 15 or 16 wherein at least one of said sensors is a load cell.

19. An airbag deployment controller according to either of claims 15 or 16 wherein at least one of said sensors is a variable resistance pressure sensor.

20. An airbag deployment controller according to either of claims 15 or 16 wherein at least one of said sensors is a variable capacitance pressure sensor.

21. An airbag deployment controller according to either of claims 15 or 16 wherein at least one of said sensors is a variable inductance pressure sensor.

22. A kit for retrofitting a vehicle seat with an airbag deployment controller comprising a frame having a plurality of sensors mounted thereon in locations which correspond to a vertically uppermost surface of a vehicle seat pan and a signal processor which processes signals from said sensors to determine the weight that is located above and resting upon said frame, said signal processor comprising

a. signal summing circuitry;

b. comparator circuitry; and

c. a switch through which an airbag firing signal must pass with each component of the signal processor being in circuit communication with another component of the signal processor.