US4893109A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Airbag electrical igniter readiness detector
Assignee: Ford Motor Co
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Filing: 1988-10-05
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Granted: 1990-01-09
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Expires: 2008-10-05
Abstract
Abstract Method and apparatus for periodically checking the critical resistance value of an airbag igniter ("squib") component and determining if the resistance exceeds a predetermined maximum value.
Inventors
- 👤 Robert J. Vrabel
- 👤 Dennis W. Rhee
- 👤 Michael R. Seeger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:48
CPC Classifications
B; B60; B60R; B60R21/00; B60R21/01; B60R21/017; B60R21/0173; B60R21/0176
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
134 words
In an automotive air bag deployment system containing an explosive igniter that is responsive to inflate an air bag when energized with an electrical current of a predetermined minimum value for a predetermined minimum time period, an apparatus for periodically checking the resistance of the igniter without causing said igniter to responsively inflate said air bag, comprising: means for applying a predetermined low energy electrical pulse to said igniter, the duration and value of said pulse being selected to be less than said predetermined minimums and therefor insufficient to cause the igniter to reactively explode; means for detecting the voltage drop across said igniter when said pulse is applied, comparing said detected voltage drop with values within a predetermined acceptable range, and providing a warning when said voltage drop is outside said acceptable range.
Claim 2
Dependent Claim
134 words
In an automotive air bag deployment system containing an explosive igniter that is responsive to inflate an air bag when energized with an electrical current of a predetermined minimum value for a predetermined minimum time period, an apparatus for periodically checking the resistance of the igniter without causing said igniter to responsively inflate said air bag, comprising: means for applying a predetermined low energy electrical pulse to said igniter, the duration and value of said pulse being selected to be less than said predetermined minimums and therefor insufficient to cause the igniter to reactively explode; means for detecting the voltage drop across said igniter when said pulse is applied, comparing said detected voltage drop with values within a predetermined acceptable range, and providing a warning when said voltage drop is outside said acceptable range.
Claim 3
Dependent Claim
70 words
An apparatus as in claim 1, wherein said detecting means measures the voltage present on one side of the igniter as a first measured value and measures the voltage present on the other side of the igniter as a second measured value during the time said pulse is applied to said igniter and subtracts said second value from said first value to derive a measured voltage drop across said igniter.
Claim 4
Dependent Claim
24 words
An apparatus as in claim 2, wherein said detecting means compares said measured voltage drop with a predetermined limit for an acceptable measured voltage.
Claim 5
Dependent Claim
89 words
An apparatus as in claim 1, wherein said detecting means is a microcomputer programmed to read the analog voltage present on one side of the igniter as a first measured value and reads the analog value present on the other side of the igniter as a second measured value during the time said pulse is applied to said igniter, to convert said first and second values to digital signal representations, and to subtract said second value from said first value to derive a measured voltage drop across said igniter.
Claim 6
Dependent Claim
45 words
An apparatus as in claim 4, wherein said microcomputer is further programmed to compare said measured voltage drop with a predetermined limit for an acceptable measured voltage, and to output a warning signal when said measured voltage drop is determined to exceed said predetermined limit.
Claim 7
Dependent Claim
133 words
In an automotive air bag deployment system containing an explosive igniter that is responsive to inflate an air bag when energized with an electrical current of a predetermined minimum value for a predetermined minimum time period, a method for periodically checking the resistance of the igniter without causing said igniter to responsively inflate said air bag, comprising the steps of: applying a predetermined low energy electrical pulse to said igniter, the duration and value of said pulse being selected to be less than said predetermined minimums and therefore insufficient to cause the igniter to reactively explode; detecting the voltage drop across said igniter when said pulse is applied; comparing said detected voltage drop with values within a predetermined acceptable range; and providing a warning when said voltage drop is outside said acceptable range.
Claim 8
Dependent Claim
133 words
In an automotive air bag deployment system containing an explosive igniter that is responsive to inflate an air bag when energized with an electrical current of a predetermined minimum value for a predetermined minimum time period, a method for periodically checking the resistance of the igniter without causing said igniter to responsively inflate said air bag, comprising the steps of: applying a predetermined low energy electrical pulse to said igniter, the duration and value of said pulse being selected to be less than said predetermined minimums and therefore insufficient to cause the igniter to reactively explode; detecting the voltage drop across said igniter when said pulse is applied; comparing said detected voltage drop with values within a predetermined acceptable range; and providing a warning when said voltage drop is outside said acceptable range.
Claim 9
Dependent Claim
74 words
A method as in claim 6, wherein said step of detecting includes the steps of measuring the voltage present on one side of the igniter as a first measured value, measuring the voltage present on the other side of the igniter as a second measured value during the time said pulse is applied to said igniter, and subtracting said second value from said first value to derive a measured voltage drop across said igniter.
Claim 10
Dependent Claim
30 words
An apparatus as in claim 7, wherein said step of detecting further includes the step of comparing said measured voltage drop with a predetermined limit for an acceptable measured voltage.
Claim 11
Dependent Claim
92 words
A method as in claim 6, wherein said step of detecting is performed with a microcomputer programmed to read the analog voltage present on one side of the igniter as a first measured value, to read the analog value present on the other side of the igniter as a second measured value during the time said pulse is applied to said igniter, to convert said first and second values to digital signal representations, and to subtract said second value from said first value to derive a measured voltage drop across said igniter.
Claim 12
Dependent Claim
45 words
A method as in claim 9, wherein said microcomputer is further programmed to compare said measured voltage drop with a predetermined limit for an acceptable measured voltage, and to output a warning signal when said measured voltage drop is determined to exceed said predetermined limit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-08 | 1993-07-10 | 1994-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-08 | 1997-07-10 | 1998-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-08 | 2001-07-10 | 2002-01-09 | $7700.00 | Window Closed / Lapsed |