Apparatus for actuating vehicle safety devices

• US 3,911,391 A
• Filed: 02/28/1973
• Issued: 10/07/1975
• Est. Priority Date: 05/05/1972
• Status: Expired due to Term

• Current Assignee: Franz Rudolf Thomanek, Johann Spies, Manfred Held
• Original Assignee: Franz Rudolf Thomanek, Johann Spies, Manfred Held
• Inventors: Held, Manfred, Spies, Johann, Thomanek, Franz Rudolf
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Nowicki, Joseph E.
• Application Number:
  US05/336,791
• Time in Patent Office: 951 Days
• Field of Search: 340/52R,52H,262 307/1R 280/15B,15AB 180/91,103,15E 303/21BE
• US Class Current: 180/274
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: B60R 21/0133 by integrating the amplitude of the input signal
• CPC Class Codes: B60R 21/01526 using piezoelectric elements
• CPC Class Codes: B60R 21/0173 Diagnostic or recording means therefor
• CPC Class Codes: G01P 15/09 by piezoelectric pick-up

Abstract

A sensor mounted in the vehicle produces a signal corresponding to the acceleration of the vehicle. A limiter coupled to the sensor reduces the signal by a value corresponding to the acceleration which can safely be absorbed by passengers in the vehicle. An integrator coupled to the limiter integrates the output of the limiter. A threshold device responsive to the output of the integrator produces an indication when the output of the integrator exceeds a given level so as to actuate a safety device such as an air bag.

Claims

1. An apparatus for actuatiNg a safety device to protect passengers of a vehicle, comprising sensor means mounted in the vehicle for producing a signal corresponding to the acceleration of the vehicle, limiter means coupled to said sensor means for clipping off a portion of the signal below a value corresponding to the normal accelerations of the vehicle, integrating means coupled to said limiter means for integrating the output of said limiter means, threshold responsive means coupled to said integrating means for producing an indication when the output of said integrating means exceeds a given level so as to actuate the safety device, pulse generator means coupled to said limiter means for producing two successive pulses and applying them to said limiter means, both of said pulses being greater than the value, the first of said pulses being sufficient to produce an output from said integrating means less than the given level and the second greater than the given level, comparator means coupled to and responsive to the output of said threshold responsive means and said pulse generator means, coincidence gate means coupled to and responsive to the output of said comparator means and to the output of said threshold responsive means, said coincidence gate means being substantially disabled by an output of said comparator means, said comparator means producing a signal at said coincidence gate means only if a single signal appears at the output of said threshold responsive means, and an alarm indicator coupled to and responsive to said comparator means for producing a signal in response to an output from said comparator means.

2. An apparatus as in claim 1, wherein said sensor means includes a piezoelectric acceleration detector and a series connected amplifier.

3. An apparatus as in claim 2, wherein said sensor means includes a resistor in series with said piezoelectric detector, said pulse generator means applying the pulse between said resistor and said detector.

4. An apparatus as in claim 1 wherein said sensor means includes a piezoelectric acceleration detector and a series connected amplifier, and wherein said limiter means further clips off a portion of the signal from said sensor means which exceeds a second value, so that said limiter means transmits only the portion of the signal from the sensor means between the two values.

5. An apparatus as in claim 1, wherein said integrating means has a discharge time constant of between 5 and 500 ms.

6. An apparatus for actuating a safety device to protect passengers of a vehicle, comprising sensor means mounted in the vehicle for producing a signal corresponding to the acceleration of the vehicle, limiter means coupled to said sensor means for clipping off a portion of the signal below a value corresponding to the normal accelerations of the vehicle, integrating means coupled to said limiter means for integrating the output of said limiter means, threshold responsive means coupled to said integrating means for producing an indication when the output of said integrating means exceeds a given value so as to actuate the safety device, and, pulse generator means for producing two successive pulses and applying them to said limiter means, both of said pulses being greater than the value corresponding to the normal accelerations of the vehicle, only the second of said pulses being sufficient to produce an output from said threshold responsive means, comparator means coupled to the output of said threshold responsive means and said pulse genreator, coincidence gate means coupled to and responsive to the output of said comparator means and to the output of said threshold responsive means, said coincidence gate means being substantially disabled by an output of said comparator means, said comparator producing a signal at said coincidence gate means only if a single signal appears at the output of said threshold responsive means, and an alarm indicator responsive to said comparator for producing a signal in response to an output From said comparator means, ignition means coupled to the output of said coincidence gate means for exciting the safety device, constant current source means connected to said ignition means, comparison means coupled to the output of said ignition means and said constant current source means for comparing the voltage drop across said ignition means with the output of said constant current source means and producing a signal when the comparison between the two departs from a predetermined condition.

7. An apparatus for actuating a safety device to protect passengers of a vehicle, comprising sensor means mounted in the vehicle for producing a signal corresponding to the acceleration of the vehicle, limiter means coupled to said sensor means for clipping off a portion of the signal below a value corresponding to the normal acceleration of the vehicle, integrating means coupled to said limiter means for integrating the output of said limiter means, threshold responsive means coupled to said integrating means for producing an indication when the output of said integrating means exceeds a given value so as to actuate the safety device, ignition means coupled to said threshold means for exciting the safety device in response to a signal from said threshold responsive means, constant current source means connected to said ignition means, comparison means coupled to the output of said ignition means and said constant current source means for comparing the voltage drop across said ignition means with the output of said constant current source means and producing a signal when the comparison between the two departs from a predetermined condition, said sensor means includes a piezoelectric acceleration detector and a series connected amplifier.