Patent EP0093971A2 successfully refreshed from Google Patents.
EP0396265A2
Expired / Lapsed
EP
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Air bag firing circuit
Assignee: Automotive Systems Laboratory Inc
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Filing: 1990-04-09
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Granted: —
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Expires: 2010-04-09
Abstract
Abstract An air bag firing circuit comprises a firing path (52) including in series a safing sensor (54), a squib (56), and a crash sensor (58). Each sensor comprises normally-open switch means (94) operated by an inertial mass and shunted by a resistor (84). A battery (82) maintains a known voltage across the firing path while suitable control means (80) checks the integrity of the firing path by reading and comparing the voltages achieved at various points (86,88,90) thereabout. The control means further tests each sensor individually by sequentially operating suitable test means incorporated therein, such as means (92) for biasing the inertial mass of each sensor towards its switch means to operate same, while determining the effect of such testing on the voltages achieved about the firing path. Upon the detection of a sensor failure, the malfunctioning sensor is removed from the firing path as by operating low-resistance shunt means (98) therefor, or by operating means incorporated within the sensor for operating the switch means thereof without regard to acceleration, such as means (92) for biasing its inertial mass towards its switch means to close same, thereby ensuring continued protection of the vehicle passengers until the sensor is serviced or replaced. If the malfunctioning sensor is the high-threshold crash sensor (58), the control means operates means on the low-threshold safing sensor (54) to increase the threshold thereof upon removal of the crash sensor from the firing path, thereby providing continuing protection for vehicle passengers.
Inventors
- 👤 Leonard Werner Behr
- 👤 Graig William White
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 04:23
CPC Classifications
B; B60; B60R; B60R21/00; B60R21/01; B60R21/017; B60R21/0173; B60R21/0176; B60R21/02; B60R21/16; G; G01; G01P; G01P21/00
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
124 words
In a control circuit for a vehicle passenger restraint comprising first signal-generating means for generating a first output signal in response to an acceleration input exceeding a first threshold; second signal-generating means for generating a second output signal in response to an acceleration input exceeding a second threshold; and trigger means, in communication with said first and second signal-generating means, for actuating said vehicle passenger restraint upon simultaneous receipt of said first and second signals therefrom; the improvement comprising failure detecting means for detecting a failure of said second signal-generating means to properly respond to acceleration; and third signal-generating means responsive to said failure detecting means, in communication with said trigger means, for generating said second signal upon failure of said second signal-generating means.
Claim 2
Dependent Claim
124 words
In a control circuit for a vehicle passenger restraint comprising first signal-generating means for generating a first output signal in response to an acceleration input exceeding a first threshold; second signal-generating means for generating a second output signal in response to an acceleration input exceeding a second threshold; and trigger means, in communication with said first and second signal-generating means, for actuating said vehicle passenger restraint upon simultaneous receipt of said first and second signals therefrom; the improvement comprising failure detecting means for detecting a failure of said second signal-generating means to properly respond to acceleration; and third signal-generating means responsive to said failure detecting means, in communication with said trigger means, for generating said second signal upon failure of said second signal-generating means.
Claim 3
Dependent Claim
35 words
The control circuit of claim 1 wherein said second signal-generating means comprises switch means; and said failure detecting means comprises first switch-operating means for testing said switch means by operating same without regard to acceleration.
Claim 4
Dependent Claim
79 words
The control circuit of claim 2 wherein said second signal generating means comprises first biasing means for biasing said switch means thereof to a first position, said first biasing means being overcome by an acceleration input exceeding said second threshold, whereupon said switch means is switched in response to such acceleration to a second position; and said first switch-operating means of said failure detecting means comprises second biasing means operative to bias said switch means to said second position.
Claim 5
Dependent Claim
88 words
The control circuit of claim 2 wherein said second signal-generating means further comprises second switch-operating means including an inertial mass for operating said switch means of said second signal-generating means, and first biasing means for biasing said inertial mass away from said switch means, said inertial mass operating said switch means when said first biasing means is overcome by an input acceleration exceeding said second threshold; and said first switch-operating means comprises second biasing means operative to bias said inertial mass toward said switch means to operate same.
Claim 6
Dependent Claim
66 words
The control circuit of claim 2 wherein said failure detecting means further comprises signal detecting means for detecting the output of said second signal-generating means; and comparator means, in communication with said signal detecting means, for comparing said detected output of said second signal-generating means before operating said first switch-operating means with said detected output of said second signal-generating means when operating said first switch-operating means.
Claim 7
Dependent Claim
64 words
The control circuit of claim 1 wherein said first and second signal-generating means comprise first and second normally-open switch means which close in response to acceleration inputs exceeding said first and second thresholds, respectively; and including a firing path comprising in series said first switch means, said trigger means, and said second switch means; and means for applying a voltage across said firing path.
Claim 8
Dependent Claim
90 words
The control circuit of claim 6 wherein said trigger means has internal electrical resistance; said first and second switch means are shunted by a first and second resistor, respectively, said first and second resistors having a resistance substantially greater than said internal resistance of said trigger means; and said failure detecting means comprises means for reading the voltages achieved at a plurality of points on said firing path, and comparator means for comparing the voltage achieved at one of said points with the voltage achieved at another of said points.
Claim 9
Dependent Claim
75 words
The control circuit of claim 6 wherein said failure detecting means comprises switch-closing means for closing said second switch means without regard to acceleration; voltage-detecting means for detecting the voltage drop across said second switch means; and comparator means, in communication with said voltage detecting means, for comparing the voltage drop across said second switch means before operating said switch-closing means with the voltage drop across said second switch means when operating said switch-closing means.
Claim 10
Dependent Claim
26 words
The control circuit of claim 1 wherein said second signal-generating means comprises switch means; and said third signal-generating means comprises means for shunting said switch means.
Claim 11
Dependent Claim
32 words
The control circuit of claim 1 wherein said second signal-generating means comprises switch means; and said third signal-generating means comprises first switch-operating means for operating said switch means without regard to acceleration.
Claim 12
Dependent Claim
78 words
The control circuit of claim 10 wherein said second signal-generating means comprises first biasing means for biasing said switch means thereof to a first position, said first biasing means being overcome by an acceleration input exceeding said second threshold, whereupon said switch means is switched in response to such acceleration to a second position; and said first switch-operating means of said third signal-generating means comprises second biasing means operative to bias said switch means to said second position.
Claim 13
Dependent Claim
88 words
The control circuit of claim 10 wherein said second signal-generating means further comprises second switch-operating means including an inertial mass for operating said switch means of said second signal-generating means, and first biasing means for biasing said inertial mass away from said switch means, said inertial mass operating said switch means when said first biasing means is overcome by an acceleration input exceeding said second threshold; and said first switch-operating means comprises second biasing means operative to bias said inertial mass toward said switch means to operate same.
Claim 14
Dependent Claim
62 words
The control circuit of claim 1 wherein said second threshold is nominally greater than said first threshold, and including means responsive to said failure detecting means for increasing said first threshold above its nominal value, whereby an acceleration input greater than said nominal value of said first threshold is required to generate said first signal upon failure of said second signal-generating means.
Claim 15
Dependent Claim
87 words
The control circuit of claim 13 wherein said first signal-generating means comprises first biasing means for biasing said switch means thereof to a first position, said first biasing means being overcome by an acceleration input exceeding said first threshold, whereupon said switch means is switched in response to such acceleration to a second position; and said means responsive to said failure detecting means for increasing said first threshold above its nominal value comprises second biasing means operative to increasingly bias said switch means to said first position.
Claim 16
Dependent Claim
87 words
The control circuit of claim 13 wherein said first signal-generating means comprises an inertial mass, switch means, and first biasing means for biasing said inertial mass away from said switch means, said inertial mass operating said switch means when said first biasing means is overcome by an acceleration exceeding said first threshold; and said means responsive to said failure detecting means for increasing said first threshold above its nominal value comprises second biasing means for increasing the bias on said inertial mass away from said switch means.
Claim 17
Dependent Claim
26 words
The control circuit of claim 1 including indicator means responsive to said failure detecting means for indicating failure of said second signal-generating means upon detection thereof.
Claim 18
Dependent Claim
14 words
The control circuit of claim 16 wherein said indicator means comprises a signal lamp.
Claim 19
Dependent Claim
134 words
A control circuit for a vehicle passenger restraint comprising a firing path including in series trigger means for actuating said restraint, said trigger means having internal electrical resistance; and first and second normally-open switch means which close in response to an acceleration input exceeding a first and second threshold, respectively, said first and second switch means being shunted, respectively, by first and second shunting resistors, each of said shunting resistors having a resistance substantially greater than the internal resistance of said trigger means; means for applying a voltage across said firing path; failure detecting means for detecting a failure of said second switch means to properly respond to acceleration; and shunt means responsive to said failure detecting means for shunting said second switch means upon detection of a failure of said second switch means.
Claim 20
Dependent Claim
134 words
A control circuit for a vehicle passenger restraint comprising a firing path including in series trigger means for actuating said restraint, said trigger means having internal electrical resistance; and first and second normally-open switch means which close in response to an acceleration input exceeding a first and second threshold, respectively, said first and second switch means being shunted, respectively, by first and second shunting resistors, each of said shunting resistors having a resistance substantially greater than the internal resistance of said trigger means; means for applying a voltage across said firing path; failure detecting means for detecting a failure of said second switch means to properly respond to acceleration; and shunt means responsive to said failure detecting means for shunting said second switch means upon detection of a failure of said second switch means.
Claim 21
Dependent Claim
51 words
The control circuit of claim 18 wherein said firing path further includes third normally-open switch means in parallel with said second switch means which closes in response to an acceleration input exceeding a third threshold; and said shunting means comprises means for closing said third switch means without regard to acceleration.
Claim 22
Dependent Claim
128 words
A control circuit for a vehicle passenger restraint comprising a firing path including in series trigger means for actuating said restraint, said trigger means having internal electrical resistance; and first and second normally-open switch means which close in response to an acceleration input exceeding a first and second threshold, respectively, said first and second switch means being shunted, respectively, by first and second shunting resistors, each of said shunting resistors having a resistance substantially greater than the internal resistance of said trigger means; means for applying a voltage across said firing path; failure detecting means for detecting a failure of said second switch means to properly respond to acceleration; and switch-closing means responsive to said failure detecting means for closing said second switch means without regard to acceleration.
Claim 23
Dependent Claim
128 words
A control circuit for a vehicle passenger restraint comprising a firing path including in series trigger means for actuating said restraint, said trigger means having internal electrical resistance; and first and second normally-open switch means which close in response to an acceleration input exceeding a first and second threshold, respectively, said first and second switch means being shunted, respectively, by first and second shunting resistors, each of said shunting resistors having a resistance substantially greater than the internal resistance of said trigger means; means for applying a voltage across said firing path; failure detecting means for detecting a failure of said second switch means to properly respond to acceleration; and switch-closing means responsive to said failure detecting means for closing said second switch means without regard to acceleration.
Claim 24
Dependent Claim
44 words
The control circuit of claim 18,19 20; wherein said failure detecting means comprises voltage-detecting means for detecting the voltage at a point on said firing path; and comparator means for comparing the voltages at said point before and during operation of said switch-closing means.
Claim 25
Dependent Claim
50 words
The control circuit of claim 18, 19 or 20, wherein said failure detecting means comprises voltage-detecting means for detecting the voltages at a plurality of points on said firing path; and comparator means for comparing the voltage at one of said points with the voltage at another of said points.
Claim 26
Dependent Claim
65 words
The control circuit of claim 18, 19 20, wherein said second threshold is nominally greater than said first threshold; and including means responsive to said failure detecting means for increasing said first threshold above its nominal value, whereby an acceleration input greater than said nominal value of said first threshold is required to close said first switch means upon failure of said second switch means.
Claim 27
Dependent Claim
37 words
The control circuit of claim 23 wherein said means responsive to said failure detecting means for increasing said first threshold above its nominal value comprises additional means for biasing said first switch means in said normally-open position.
References Cited (Backward Citations)
No citation records indexed.
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