Operation recorder for motor vehicle safety device

• US 3,949,357 A
• Filed: 07/30/1974
• Issued: 04/06/1976
• Est. Priority Date: 02/09/1972
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Hosaka, Akio
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Nowicki, Joseph E.
• Application Number:
  US05/493,133
• Time in Patent Office: 616 Days
• Field of Search: 340/52 R, 340/52 H, 340/248 A, 340/214, 340/262, 340/61, 307/10 R, 180/91, 180/103 R, 180/103 A, 280/150 AB
• US Class Current: 180/274
• CPC Class Codes: B60R 21/0176 for firing circuits using only mechanical switches as collision detecting means, in series with pyrotechnic fuses

Abstract

An operation recorder to record a malfunction of a safety device or to record a proper function of the safety device comprises an AND-output gate. The AND-output gate is connected at its input side with the outputs of first and second monostable-multivibrators and at its output side to a memory. The first monostable-multivibrator normally generates a logical one output and a logical zero output signal, when it is triggered by the output of a collision sensor, for 10 to 100 milliseconds. The second monostable-multivibrator normally generates a logical zero output signal and a logical one output signal, when a safety device is actuated, for relatively shorter time than 10 to 100 milliseconds. The AND-output gate supplies a logical one output to the memory to generate the same when it receives logical one input signals.

Claims

1. In a motor vehicle having a collision sensor adapted to provide an output upon a collision of the motor vehicle, and a safety device adapted to be actuated by a trigger mechanism which includes an electrically actuable detonation element, having a relatively small resistance, a DC power source, first and second normally open collision responsive switch means connected to opposite sides of said electrically actuable detonation element and to said DC source, and first and second resistor means connected across first and second switch means:

an operation recorder to record a mulfunction of said safety device comprising;

first means connected to said collision sensor to receive the output thereof, said first means being operable response to the output of said collision sensor to provide a logical zero output having a predetermined time duration;

second means including a first comparator gate means responsive to a voltage at a junction between said first normally open responsive switch means and said electrically detonation element for providing a logical one output when the voltage at said junction exceeds a first predetermined reference voltage;

inverter means connected to said first comparator gate means to receive the output thereof for providing a logical zero output responsive to the logical one output of said first comparator gate means;

a second comparator gate means responsive to a voltage at a junction between said electrically actuable detonation element and said second normally open collision responsive switch means for providing a logical zero output when the voltage at said last mentioned junction is below a second predetermined reference voltage which is set to be relatively smaller than said predetermined first reference voltage of said first comparator gate means;

an NOR logical function gate means connected to said inverter means and to said second comparator gate means to receive the outputs thereof and responsive to logical zero outputs of said inverter means and said second comparator gate means for providing a logical one output;

a monostable-multivibrator connected to said NOR logical function gate to receive the output thereof to provide a logical one output having a predetermined time duration shorter than that of the output of said first means when the output of said NOR gate switches to a logical one; and

AND logical function gate means connected to said first means to receive the output thereof and to said monostable-multivibrator to receive the output thereof, said AND logical function gate means being responsive to the logical one outputs of said first means and said monostable-multivibrator means for providing a logical one output;

a memory means; and

means, in circuitry with said memory means and AND logical function gate means, responsive to the logical one output of said AND logical function gate means for energizing said memory means.

2. An operator recorder as claimed in claim 1, in which the predetermined time duration is of the order of 100 milliseconds.

3. An operation recorder as claimed in claim 2, in which said first means is in the form of a a monostable-multivibrator.

4. An operation recorder as claimed in claim 3, in which said last mentioned means is in the form of a transistor adapted to be rendered conductive by the logical one output of said AND logical function gate.