METHOD AND APPARATUS FOR DETECTING THE UTILIZATION OF A VEHICLE SAFETY BELT

• US 3,806,867 A
• Filed: 06/04/1971
• Issued: 04/23/1974
• Est. Priority Date: 06/04/1971
• Status: Expired due to Term

• Current Assignee: Norman G. Quantz
• Original Assignee: Norman G. Quantz
• Inventors: Quantz, Norman G.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Leimer, Kenneth N.
• Application Number:
  US05/150,088
• Time in Patent Office: 1,054 Days
• Field of Search: 340/52,52E,278,279 280/15SB 180/82.8
• US Class Current: 340/457.1
• CPC Class Codes: B60R 2022/4816 for sensing locking of buckle
• CPC Class Codes: B60R 2022/4858 for sensing pressure on seat
• CPC Class Codes: B60R 2022/4891 preventing use of the vehicle when the seatbelt is not fastened
• CPC Class Codes: B60R 22/48 Control systems, alarms, or interlock systems, for the correct application of the belt or harness

Abstract

An apparatus for detecting the proper utilization of a safety belt of a vehicle by a vehicle occupant which includes a high frequency oscillator and at least one operatively connected sensing conductor in the safety belt and/or a seat of the vehicle. The proper utilization of the safety belt by the vehicle occupant changes the reactive impedance associated with the sensing conductor to affect the operation of the high frequency oscillator, for example, to completely detune the oscillator to yield a DC output signal which is operative to activate a warning device or ignition interlock device. Preferably, the system includes a first sensing conductor which is carried by the safety belt and which is connected to the oscillator to form a completed R.F. loop when the safety belt is secured, and a second sensing conductor which is positioned in the seat bottom to form a capacitor with the safety belt sensing conductor. The proper utilization of the safety belt by the vehicle occupant affects the capacitance value of the capacitor formed by the sensing conductors and the inductance and capacitance of the R.F. loop to effect the detuning of the oscillator.

Claims

1. In a vehicle having an occupant seat and safety belt means including securing means for holding said safety belt means about the occupant for restraining the occupant, an apparatus comprising:

first conductor means carried by and extending along said safety belt means; and

circuit means connected to said first conductor means including oscillating means for supplying oscillating electrical energy to said first conductor means;

said first conductor means providing a reactive impedance for said oscillating means so that said first conductor means is operatively cooperating with said oscillating means, the value of said reactive impedance of said first conductor means being changed from a first value when said safety belt means is not about said occupant to a second value when said safety belt means is held about said occupant by said securing means so that said first conductor means at least partly surrounds said occupant said circuit means including means for providing an output signal at least in part in response to said change from said first value to said second value of the reactive impedance of said first conductor means for detecting the utilization of said safety belt means by said occupant with said securing meAns holding said safety belt means about said occupant.

2. An apparatus according to claim 1 wherein said reactive impedance includes a capacitance and wherein said circuit means at least in part detects a change in said capacitance.

3. An apparatus according to claim 1 wherein said reactive impedance includes an inductance and wherein said circuit means at least in part detects a change in said inductance.

4. An apparatus according to claim 1 wherein said oscillating means for supplying oscillating electrical energy supplies high frequency electrical energy to said conductor means.

5. An apparatus according to claim 4 wherein said reactive impedance change affected by the presence of said occupant includes a change in inductance and wherein said circuit means at least in part detects said change in inductance.

6. An apparatus according to claim 5 wherein said high frequency energy is provided at a preselected frequency and wherein said change in inductance changes the frequency of said high frequency energy.

7. An apparatus according to claim 5 wherein said frequency is changed to zero frequency by said utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant and wherein said circuit means detects said zero frequency energy.

8. An apparatus according to claim 1 further including a second conductor means connected to said circuit means and associated with said first conductor means so as to form a capacitor therebetween, the utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant affects the capacitance of said capacitor between said conductors, and said circuit means detects said change in said capacitance.

9. An apparatus according to claim 8 wherein said oscillating means for supplying oscillating electrical energy supplies high frequency electrical energy to said conductor means, and said capacitor between said second conductor means and said first conductor means is connected to said oscillating means for varying the frequency of said oscillating means in accordance with said capacitance.

10. An apparatus according to claim 9 wherein said change in capacitance value causes said frequency of said oscillating means to be decreased to a predetermined degree, and said circuit means detects said predetermined degree of decrease of said frequency.

11. An apparatus according to claim 8 wherein said oscillating means for supplying oscillating electrical energy supplies high frequency energy to at least one of said first and second conductor means, said reactive impedance change in accordance with a predetermined positional relationship of said occupant with said first conductor means includes a change in inductance of said one conductor means, and said circuit means detects said change in inductance.

12. An apparatus according to claim 11 wherein said oscillating means provides high frequency energy at a preselected frequency and wherein said change in inductance and capacitance jointly change the frequency of said oscillating means.

13. An apparatus according to claim 12 wherein said frequency of said oscillating means is changed to zero frequency by said utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant and wherein said circuit means detects said zero frequency of said oscillating means.

14. In a vehicle having an occupant seat and safety belt means including-securing means for holding said safety belt means about the occupant for restraining the vehicle occupant, an apparatus comprising:

first conductor means associated with and extending along said safety belt means;

circuit means connected to said first conductor means including oscillating means for supplying high frequency oscillating electrical energy to said first conductor means, said first conductor means being adapted to radiate at leaSt a portion of said high frequency electrical energy to the surroundings of said first conductor means so that when said safety belt means is held about said occupant by said securing means to position said first conductor means at least partly about said occupant the radiation of said high frequency electrical energy is affected to in turn result in a change in the operation of said oscillating means; and

said circuit means further including means responsive at least in part to said change in the operation of said oscillating means for detecting the utilization of said safety belt by said occupant with said securing means holding said safety belt means about said occupant and for providing an output signal representative thereof.

15. An apparatus according to claim 14 wherein said oscillating means provides said high frequency energy at a preselected frequency and wherein said change in operation of said oscillating means is a change in the frequency of oscillation of said oscillating means.

16. An apparatus according to claim 15 wherein said frequency of said oscillating means is changed to zero frequency by said utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant and wherein said circuit means detects said zero frequency energy.

17. In a vehicle having an occupant seat and safety belt means including securing means for holding said safety belt means about the occupant for restraining the vehicle occupant, an apparatus comprising:

first conductor means associated with and extending along said belt means;

circuit means connected to said first conductor means including oscillating means for supplying high frequency electrical energy to said conductor means, said conductor means being adapted to radiate at least a portion of said high frequency electrical energy to the surroundings of said conductor means wherein the utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant and said conductor means extending at least partly about said occupant affects said high frequency electrical energy radiated from said conductor means thereby changing the operation of said circuit means; and

said circuit means further including means responsive at least in part to said change in the operation of said circuit means due to said utilization of said safety belt by said occupant with said securing means holding said safety belt means about said occupant for detecting the utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant and for providing an output signal representative thereof.

18. An apparatus according to claim 17 wherein said oscillating means provides said high frequency energy at a preselected frequency and wherein said change in said operation of said circuit means is a change in the frequency of oscillation of said oscillating means.

19. In a vehicle having an occupant seat and safety belt means including securing means for holding said safety belt means about the occupant for restraining the vehicle occupant, an apparatus comprising:

first conductor means associated with said safety belt means;

second conductor means associated with said seat;

circuit means connected to said first and second conductor means including supply means for supplying electrical energy to said first and second conductor means with said supply means including oscillating means for providing oscillating electrical energy to at least one of said first and second conductor means;

said at least one of said first and second conductor means providing a reactive impedance for said circuit means with the reactive impedance of said at least one of said first and second conductor means being changed in accordance with a predetermined positional relationship of said occupant with said at least one of said first and second conductor means; and

said circuit means being sensitive to said change in reactive impedance for detecting said change in the reactive impedance of said at least one of said first and second conductor means including means responsive at least in part to said detected change in reactive impedance and a change in said electrical energy supplied to the other of said first and second conductor means for detecting the utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant and for providing an output signal representative thereof.

20. An apparatus according to claim 19 wherein said reactive impedance includes a capacitance and wherein said circuit means detects a change in said capacitance.

21. An apparatus according to claim 19 wherein said reactive impedance includes an inductance and wherein said circuit means detects a change in said inductance.

22. An apparatus according to claim 19 wherein said safety belt means includes a pair of safety belt means portions and said securing means includes connection means for said safety belt means for connecting said pair of safety belt means portions about said occupant, and wherein said first conductor means comprises a pair of first conductor means portions which are electrically connected at said connection means when said safety belt means is held about said occupant.

23. An apparatus according to claim 19 wherein said reactive impedance is changed upon the utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant subsequent to said change in accordance with the predetermined positional relationship of said occupant with said at least one of said first and second conductor means and wherein said circuit means provides an output signal representative of said change in reactive impedance of said first conductor means upon the utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant.

24. An apparatus according to claim 23 wherein said first conductor means is said at least one of said first and second conductor means and said first conductor means forms a RF loop when said securing means holds said safety belt means about said occupant.

25. An apparatus according to claim 24 wherein said first and second conductor means form a capacitor therebetween which has a value which is different when said occupant is interposed between said first and second conductor means when said securing means holds said safety belt means about the occupant relative to the value of said capacitor when said occupant is not interposed between said first and second conductor means, and wherein said circuit means provides an output signal representative of said difference in said capacitance between said first and second conductor means.

26. An apparatus according to claim 19 wherein said first and second conductor means form a capacitor therebetween which has a value which is different when said occupant is interposed between said first and second conductor means when said securing means holds said safety belt means about the occupant relative to the value of said capacitor when said occupant is not interposed between said first and second conductor means, and wherein said circuit means provides an output signal representative of said difference in capacitance between said first and second conductor means.

27. In a vehicle having an occupant seat and safety belt means including securing means for holding said safety belt means about the occupant for restraining the vehicle occupant, an apparatus comprising:

first conductor means carried by and extending along said safety belt means;

second conductor means carried by said seat and positioned adjacent said occupant;

circuit means including oscillating means connected to said first and second conductor means for supplying oscillating electrical energy to said first and secoNd conductor means;

said first and second conductor means providing reactive impedance for said oscillating means, the reactive impedance of said first and second conductor means being changed from a first value when said safety belt means is not about said occupant to a second value upon the utilization of said safety belt means by said occupant with said securing means holding said safety belt means about said occupant so that said first conductor means at least partly surrounds said occupant and said occupant is interposed between said first and second conductor means; and

said circuit means including means for providing an output signal at least in part in response to said change in the reactive impedance of said first and second conductor means from said first value to said second value for detecting the utilization of said safety belt means by said occupant with said securing means holding said safety belt about said occupant.

28. An apparatus according to claim 27 wherein said first and second conductor means form a capacitor therebetween which has a value which is different when said occupant is interposed between said first and second conductor means when said securing means holds said safety belt means about the occupant relative to the value of said capacitor when said occupant is not interposed between said first and second conductor means, and wherein said circuit means provides an output signal representative of said difference in capacitance between said first and second conductor means.