Method for actuating a safety device for vehicle occupants

Abstract

A method of actuating a safety device for vehicle occupants, wherein the safety device has several tripping devices coupled to a capacitor and to passenger restraint devices, such as air bags, seat belts, or the like. The energy supplied by the capacitor to a tripping device is measured upon actuation of that device. If the energy supplied exceeds a predetermined limit, the flow of electric current from the capacitor to the respective tripping device is interrupted. Thus, if an actuated tripping device shunts, the energy of the capacitor is not drained by the shunt, and the capacitor maintains an energy level sufficient to actuate the other tripping devices.

We claim: 
     
       1. A method of actuating a passenger restraint device mounted on a motor vehicle, comprising the following steps: directing electric current from a voltage source to an actuating device to actuate the restraint device:   storing energy from the voltage source in a storage device, and if the voltage source is disconnected from the actuating device, directing electric current from the storage device to the actuating device to actuate the restraint device; and   measuring the energy stored within the storage device, and if the energy level of the storage device falls below a predetermined level, interrupting the flow of electric current to the actuating device to maintain a substantially predetermined amount of energy stored within the storage device to actuate other actuating devices.   
     
     
       2. A method as defined in claim 1 further comprising the following steps: upon actuation of the restraint device, measuring the flow of electric current to the actuating device; and   if there is electric current flowing to the actuating device, interrupting the flow of current thereto.   
     
     
       3. A method as defined in claim 1 further comprising the following steps: measuring the voltage across the actuating device upon actuating the restraint device; and   if there is a voltage across the actuating device, interrupting the flow of electric current thereto.   
     
     
       4. A method as defined in claim 1, wherein the energy within the storage device is measured by measuring the voltage across the storage device. 
     
     
       5. A method of actuating a vehicular passenger restraint device comprising the following steps: directing electric current from a storage device to an actuating device to actuate the actuating device and in turn the passenger restraint device; measuring the energy supplied by the storage device to the actuating device; and   if the energy supplied to the actuating device is greater than a predetermined amount, interrupting the flow of electric current to the actuating device to maintain a substantially predetermined amount of energy within the storage device to actuate other actuating devices.   
     
     
       6. A method as defined in claim 5, wherein the amount of energy supplied to the actuating device is measured by measuring the voltage across the storage device.   
     
     
       7. A method as defined in claim 5, wherein: the amount of energy supplied to the actuating device is measured by measuring the voltage across the actuating device.   
     
     
       8. A method as defined in claim 7, wherein upon actuating the passenger restraint device, if there is voltage across the actuating device, interrupting the flow of current therethrough.   
     
     
       9. A method as defined in claim 5, wherein the amount of energy supplied to the actuating device is measured by measuring the electric current flow therethrough. 
     
     
       10. A method as defined in claim 9, wherein if upon actuating the passenger restraint device, electric current continues to flow through the actuating device, the flow of electric current therethrough is interrupted.   
     
     
       11. An apparatus for actuating a vehicular safety device comprising: at least two passenger restraint devices, the restraint devices being actuated to protect passengers in the vehicle;   an electric storage device coupled to the passenger restraint devices, the electric storage device being adapted to direct electric current to the passenger restraint devices to actuate the passenger restraint devices; and   first means for generating output signals indicative of the energy supplied by the electric storage device to a respective passenger restraint device upon actuating the passenger restraint device; and   second means responsive to the output signals of the first means for interrupting the flow of electric current to a respective passenger restraint device upon an output signal exceeding a predetermined value to maintain a substantially predetermined amount of energy within the electric storage device to actuate the other passenger restraint devices.   
     
     
       12. An apparatus as defined in claim 11, wherein the first means includes a first volt meter coupled to the storage device, the first volt meter generating output signals indicative of the voltage across the storage device; and   the second means includes a control unit coupled to the first volt meter and to each restraint device, the control unit being adapted to compare the output signals of the first volt meter to corresponding reference values and to interrupt the flow of electric current to a respective restraint device if an output signal is less than a corresponding reference value.   
     
     
       13. An apparatus as defined in claim 11, wherein first means includes a plurality of second volt, meters, each second volt meter being coupled to a respective restraint device and to the second means to generate output signals indicative of the voltage across the respective restraint device, the second means being adapted to interrupt the flow of electric current to a restraint device upon actuation of that device if the respective second volt meter indicates a voltage across that device. 
     
     
       14. An apparatus as defined in claim 11, wherein the first means includes a plurality of amp meters, each amp meter being coupled to a respective restraint device and to the second means to generate output signals indicative of the electric current flowing through the respective restraint device, the second means being adapted to interrupt the flow of electric current to a restraint device upon actuation of that device if the respective amp meter indicates electric current flow therethrough.   
     
     
       15. An apparatus for actuating a plurality of passenger restraint devices mounted on a motor vehicle comprising: an electric storage device coupled to the passenger restraint devices to supply electric current thereto to actuate the restraint devices;   first means for monitoring the energy supply by the storage device to a respective restraint device and for generating output signals indicative thereof; and   second means responsive to the output signals of the first means for interrupting the flow of electric current from the electric storage device to a restraint device upon the level of the output signals exceeding a predetermined level to maintain a sufficient amount of energy in the storage device to actuate the other restraint devices.   
     
     
       16. An apparatus as defined in claim 15, wherein the electric storage device includes a capacitor, and the first means includes a volt meter coupled to the capacitor to generate output signals indicative of the voltage across the capacitor.   
     
     
       17. An apparatus as defined in claim 15, wherein the first means includes a first volt meter coupled to the storage device to generate output signals indicative of the voltage across the storage device; and   the second means compares the output signals of the first volt meter to corresponding reference values and, if an output signal falls below a corresponding reference value, the second means interrupts the flow of electric current to a respective restraint device.   
     
     
       18. An apparatus as defined in claim 15, wherein the first means includes a plurality of second volt meters, each second volt meter being coupled to a respective passenger restraint device to generate output signals indicative of the voltage across the respective restraint device; and   the second means is adapted to interrupt the flow of electric current to a restraint device if upon actuation of that device the respective second volt meter indicates a voltage across that device.   
     
     
       19. An apparatus as defined in claim 15, wherein the first means includes a plurality of amp meters, each amp meter being coupled to a respective passenger restraint device to generate output signals indicative of the electric current flowing through the respective restraint device; and the second means is adapted to interrupt the flow of electric current to a restraint device if upon actuation of that device the respective amp meter indicates electric current flowing through that device.   
     
     
       20. An apparatus for actuating a plurality of passenger restraint devices mounted on a motor vehicle comprising: an electric storage device coupled to the passenger restraint devices to supply electric current thereto to actuate the device;   a first volt meter coupled to the electric storage device to generate output signals indicative of the voltage across the storage device;   a control unit coupled to the first volt meter and the passenger restraint devices, the control unit being adapted to compare the output signals of the first volt meter to corresponding reference values upon actuation of a restraint device and, if .[.an.]. .Iadd.one of the .Iaddend.output signals .Iadd.of the first volt meter .Iaddend.is less than a corresponding reference value, to interrupt the flow of electric current to the respective restraint device, and thus maintain sufficient energy in the storage device to actuate other restraint devices.   
     
     
       21. An apparatus as defined in claim 20, further comprising: a plurality of second volt meters, each second volt meter being coupled to a respective .Iadd.one of the plurality of .Iaddend.restraint .[.device.]. .Iadd.devices .Iaddend.and the control unit to generate output signals indicative of the voltage across the respective .Iadd.one of the plurality of .Iaddend.restraint .[.device.]. .Iadd.devices, .Iaddend.wherein   the control unit is adapted to interrupt the flow of electric current to .[.a.]. .Iadd.the .Iaddend.respective .Iadd.one of the plurality of .Iaddend.restraint .[.device.]. .Iadd.devices .Iaddend.if upon actuation of .[.that.]. .Iadd.the respective one of the plurality of .Iaddend.restraint .[.device.]. .Iadd.devices, .Iaddend.the respective second volt meter indicates a voltage across .[.that device.]. .Iadd.the respective one of the plurality of restraint devices. .Iaddend.   
     
     
       22. An apparatus as defined in claim 20, further comprising: a plurality of amp meters, each amp meter being coupled to a respective .Iadd.one of the plurality of .Iaddend.restraint .[.device.]. .Iadd.devices .Iaddend.and the control unit to generate output signals indicative of the electric current flowing through the respective .Iadd.one of the plurality of .Iaddend.restraint .[.device.]. .Iadd.devices, .Iaddend.wherein   the control unit is adapted to interrupt the flow of electric current to .[.a.]. .Iadd.the .Iaddend.respective .Iadd.one of the plurality of .Iaddend.restraint .[.device.]. .Iadd.devices.Iaddend.if upon actuation of .[.that.]. .Iadd.the respective one of the plurality of .Iaddend.restraint .[.device.]. .Iadd.devices, .Iaddend.the respective amp meter indicates electric current flowing through .[.that.]. .Iadd.the respective one of the plurality of .Iaddend.restraint .[.device.]. .Iadd.devices..Iaddend. .Iadd.   
     
     
       23.  A method of actuating a first and second passenger restraint device mounted on a motor vehicle, comprising the following steps: directing electric current from an electric storage device to a first actuator coupled to the electric storage device for actuating the first passenger restraint device;   decoupling the electric storage device from the first actuator upon actuation of the first restraint device;   coupling the electric storage device to a second actuator a preselected period of time after the actuation of the first restraint device; and   directing electric current from the electric storage device to the second actuator for actuating the second passenger restraint device..Iaddend. .Iadd.24. The method as defined in claim 23, further comprising the step of detecting an occurrence of an accident condition, and wherein electric current is directed from the electric storage device to the first actuator in response to the occurrence of the accident condition..Iaddend. .Iadd.25. The method as defined in claim 23, wherein the first and second passenger restraint devices are first and second air bags, respectively..Iaddend. .Iadd.26. A method of inflating at least two air bags positioned in a motor vehicle, comprising the following steps:   determining an occurrence of an accident condition;   supplying energy from an energy storage device to a first actuator in response to the occurrence of the accident condition for inflating a first of the at least two air bags;   interrupting the supply of energy from the energy storage device to the first actuator upon inflation of the first air bag;   coupling the energy storage device to a second actuator a preselected period of time after the occurrence of the accident condition; and   supplying energy from the energy storage device to the second actuator for inflating a second of the at least two air bags..Iaddend. .Iadd.27. The method as defined in claim 26, wherein the step of interrupting the supply of energy includes the step of decoupling the energy storage device from the first actuator..Iaddend. .Iadd.28. The method as defined in claim 26, wherein the energy storage device is coupled to the second actuator after the supply of energy to the first actuator is interrupted..Iaddend. .Iadd.29. A method of actuating at least two safety devices of a vehicle, comprising the steps of:   determining an occurrence of an accident condition;   providing energy from an energy storage device to a first actuator in response to the occurrence of the accident condition for actuating a first of the at least two safety devices;   ceasing to provide energy to the first actuator in response to actuation of the first safety device; and   providing energy from the energy storage device to a second actuator a preselected period of time after the determination of the occurrence of the accident condition for actuating a second of the at least two safety devices..Iaddend. .Iadd.30. The method as defined in claim 29, wherein the step of ceasing to provide energy includes the step of decoupling the   
     
     
        energy storage device from the first actuator..Iaddend. .Iadd.31.  The method as defined in claim 29, wherein the step of providing energy to the second actuator includes the step of coupling the energy storage device to the second actuator..Iaddend. .Iadd.32. The method as defined in claim 31, wherein the energy storage device is coupled to the second actuator after the provision of energy is ceased..Iaddend. .Iadd.33. An apparatus for actuating a first and second passenger restraint device mounted on a motor vehicle, comprising: first and second means for actuating the first and second passenger restraint devices, respectively;   an electric storage device coupled to the first means for actuating;   means for directing electric current from the electric storage device to the first means for actuating to actuate the first passenger restraint device in response to the electric current;   means for decoupling the electric storage device from the first means for actuating after actuation of the first passenger restraint device; and   means for coupling the electric storage device to the second means for actuating a preselected amount of time after the electric storage device is decoupled from the first means for actuating, the electric storage device directing electric current to the second means for actuating to actuate the second passenger restraint device in response to the electric current..Iaddend. .Iadd.34. The apparatus as defined in claim 33, wherein the first and second passenger restraint devices are first and second air bags, respectively, and wherein the first second means for actuating include first and second ignition tablets, respectively, for inflating the first and second air bags, respectively..Iaddend. .Iadd.35. The apparatus as defined in claim 33, further comprising first and second switching devices coupled between the first and second means for actuating, respectively, and the electric storage device..Iaddend. .Iadd.36. The apparatus as defined in claim 33, wherein the first and second means for actuating are coupled in parallel..Iaddend. .Iadd.37. The apparatus as defined in claim 33, further comprising an acceleration sensor for detecting an occurrence of an accident condition..Iaddend. .Iadd.38. The apparatus as defined in claim 33, wherein the electric storage device is a capacitor..Iaddend. .Iadd.39. An apparatus for actuating a first and second passenger restraint device mounted on a motor vehicle, comprising:   first and second actuators for actuating the first and second passenger restraint devices, respectively;   an electric storage device selectively coupled to the first and second actuators, the electric storage device providing electric current to the first actuator when coupled to the first actuator, and providing electric current to the second actuator when coupled to the second actuator a predetermined amount of time after the electric storage device is decoupled from the first actuator; and   a time control unit for controlling coupling of the electric storage device..Iaddend. .Iadd.40. An apparatus for actuating at least one passenger safety device of a motor vehicle, comprising:   a sensor for generating a signal in response to a deceleration of the vehicle;   at least two actuators for actuating the at least one passenger safety device;   a power storage device for providing electric current to a first of the at least two actuators to ignite the first actuator in response to the signal from the sensor; and   a control device for coupling a second of the at least two actuators to the power storage device at a predetermined time after the signal is generated by the sensor, the power storage device providing electric current to the second actuator to ignite the second actuator..Iaddend. .Iadd.41. The apparatus as defined in claim 40, further comprising means for decoupling the first actuator from the power storage device..Iaddend. .Iadd.42. The apparatus as defined in claim 41, wherein the means for decoupling includes a switching device..Iaddend. .Iadd.43. The apparatus as defined in claim 40, wherein the at least one passenger safety device includes at least one air bag, and wherein the at least two actuators includes at least two ignition tablets for inflating the at least one air bag..Iaddend. .Iadd.44. The apparatus as defined in claim 40, wherein the at least two actuators are coupled in parallel..Iaddend. .Iadd.45. An apparatus for actuating at least two safety devices positioned in a vehicle, comprising:   means for determining an occurrence of an accident condition;   means for providing energy from an energy storage device to a first actuator in response to the occurrence of the accident condition for actuating a first of the at least two safety devices;   means for ceasing to provide energy to the first actuator in response to actuation of the first safety device; and means for providing energy from the energy storage device to a second actuator a preselected period of time after the determination of the occurrence of the accident condition for actuating a second of the at least two safety devices..Iaddend. .Iadd.46. The apparatus as defined in claim 45, wherein the means for determining includes an acceleration sensor..Iaddend. .Iadd.47. The apparatus as defined in claim 45, wherein the first and second safety devices are first and second air bags, respectively, and wherein the first and second actuators include first and second ignition tablets, respectively, for inflating the first and second air bags, respectively..Iaddend. .Iadd.48. The apparatus as defined in claim 45, wherein the first and second actuators are coupled in parallel..Iaddend. .Iadd.49. The apparatus as defined in claim 45, wherein the energy storage device is a capacitor..Iaddend.