US3680923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anti-lock brake control with sensor monitoring circuit
Assignee: Motors Liquidation Co
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Filing: 1971-03-15
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Granted: 1972-08-01
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Expires: 1991-03-15
Abstract
Abstract A four-wheel anti-lock brake control has at least three wheel speed sensors, each having one side grounded. One sensor for a non-driven wheel is monitored to assure circuit continuity between the sensor and the control circuit. All the sensor outputs are monitored by a self-check circuit to detect any sensor malfunction and to disable the control in the event of a malfunction. The self-check circuit further disables the control if a substantially zero rear wheel speed is indicated during periods of substantial front wheel speed, thus preventing the occurrence of anti-lock brake cycling in the front wheels when the rear wheels approach a lock-up condition. The self-check circuit further disables the control when any brake modulator is not in its normal position prior to a request by the control for anti-lock operation. In each case, the self-check circuit will disable the control only after some predetermined time delay. Two different time delays are accomplished using a single timing capacitor. A circuit is provided to release the rear brakes briefly when and if the front brakes are released first by the anti-lock control.
Inventors
- 👤 Philip R Peterson
- 👤 Robert H Wind
- 👤 Douglas E Mark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:13
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/88; B60T8/885; B60T2270/00; B60T2270/40; B60T2270/406; B60T2270/416
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
146 words
In an anti-lock brake control for a vehicle having a plurality of braked wheels and a plurality of sensors for detecting speed of the wheels, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when one of the sensor outputs exceeds a predetermined value, and producing a first signal indicating a minimum vehicle speed, means for determining when another sensor output is below a lower predetermined value and producing a second signal, means producing a third signal only prior to the first brake release effected by the anti-lock brake control, and means responsive to the first, second and third signals for disabling the anti-lock brake control when all signals are present whereby the control is rendered inoperative by a sensor malfunction as indicated by an output below the predetermined value occurring at a minimum vehicle speed prior to an antilock brake release.
Claim 2
Dependent Claim
146 words
In an anti-lock brake control for a vehicle having a plurality of braked wheels and a plurality of sensors for detecting speed of the wheels, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when one of the sensor outputs exceeds a predetermined value, and producing a first signal indicating a minimum vehicle speed, means for determining when another sensor output is below a lower predetermined value and producing a second signal, means producing a third signal only prior to the first brake release effected by the anti-lock brake control, and means responsive to the first, second and third signals for disabling the anti-lock brake control when all signals are present whereby the control is rendered inoperative by a sensor malfunction as indicated by an output below the predetermined value occurring at a minimum vehicle speed prior to an antilock brake release.
Claim 3
Dependent Claim
188 words
In an anti-lock brake control for a vehicle having a plurality of braked wheels and a plurality of sensors for detecting speed of the wheels, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when one of the sensor outputs exceeds a predetermined value, and producing a first signal indicating a minimum vehicle speed, means for determining when another sensor output is below a lower predetermined value and producing a second signal, means producing a third signal only prior to the first brake release effected by the anti-lock brake control, means for detecting circuit continuity between a sensor and the control and producing a fourth signal when continuity is absent, and means responsive to the first, second, and third signals for disabling the anti-lock brake control when those signals are present and responsive to the fourth signal for disabling the anti-lock brake control when the fourth signal is present whereby the control is rendered inoperative by a sensor malfunction as indicated by a discontinuity or by an output below the predetermined value occurring at a minimum vehicle speed prior to an anti-lock brake release.
Claim 4
Dependent Claim
188 words
In an anti-lock brake control for a vehicle having a plurality of braked wheels and a plurality of sensors for detecting speed of the wheels, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when one of the sensor outputs exceeds a predetermined value, and producing a first signal indicating a minimum vehicle speed, means for determining when another sensor output is below a lower predetermined value and producing a second signal, means producing a third signal only prior to the first brake release effected by the anti-lock brake control, means for detecting circuit continuity between a sensor and the control and producing a fourth signal when continuity is absent, and means responsive to the first, second, and third signals for disabling the anti-lock brake control when those signals are present and responsive to the fourth signal for disabling the anti-lock brake control when the fourth signal is present whereby the control is rendered inoperative by a sensor malfunction as indicated by a discontinuity or by an output below the predetermined value occurring at a minimum vehicle speed prior to an anti-lock brake release.
Claim 5
Dependent Claim
143 words
In an anti-lock brake control for a vehicle having a plurality of braked wheels, and a wheel speed sensor for each non-driven braked wheel, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when one of the sensor outputs exceeds a predetermined minimum value to produce a first signal indicating a minimum vehicle speed, means operative prior to the first brake release of an anti-lock brake control cycle for determining when another sensor output is substantially nil to produce a second signal indicating a malfunction of the said another sensor, and means responsive to the first and second signal for disabling the anti-lock brake control when the first and second signals have been present for a predetermined time period, whereby a sensor malfunction prior to the first anti-lock brake release and during minimum vehicle speed renders the control inoperative.
Claim 6
Dependent Claim
143 words
In an anti-lock brake control for a vehicle having a plurality of braked wheels, and a wheel speed sensor for each non-driven braked wheel, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when one of the sensor outputs exceeds a predetermined minimum value to produce a first signal indicating a minimum vehicle speed, means operative prior to the first brake release of an anti-lock brake control cycle for determining when another sensor output is substantially nil to produce a second signal indicating a malfunction of the said another sensor, and means responsive to the first and second signal for disabling the anti-lock brake control when the first and second signals have been present for a predetermined time period, whereby a sensor malfunction prior to the first anti-lock brake release and during minimum vehicle speed renders the control inoperative.
Claim 7
Dependent Claim
190 words
In an anti-lock brake control for a vehicle having a pair of braked non-driven wheels each equipped with a wheel speed sensor and a pair of braked driven wheels equipped with at least one wheel speed sensor, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when one of the sensor outputs for the non-driven wheels exceeds a predetermined minimum value to produce a first signal indicating a minimum vehicle speed, means operative prior to the first brake release of an anti-lock brake control cycle for determining when the other sensor output for a non-driven wheel is substantially nil to produce a second signal indicating a malfunction of the said other sensor, means for determining when a driven wheel seNsor output is substantially nil to produce a third signal indicating a malfunction of the said driven wheel sensor, logic means responsive to the said signals for producing an output when the first signal and either of the second and third signals are present, and timing means responsive to the logic output for disabling the anti-lock control when the logic output is present for a predetermined time.
Claim 8
Dependent Claim
190 words
In an anti-lock brake control for a vehicle having a pair of braked non-driven wheels each equipped with a wheel speed sensor and a pair of braked driven wheels equipped with at least one wheel speed sensor, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when one of the sensor outputs for the non-driven wheels exceeds a predetermined minimum value to produce a first signal indicating a minimum vehicle speed, means operative prior to the first brake release of an anti-lock brake control cycle for determining when the other sensor output for a non-driven wheel is substantially nil to produce a second signal indicating a malfunction of the said other sensor, means for determining when a driven wheel seNsor output is substantially nil to produce a third signal indicating a malfunction of the said driven wheel sensor, logic means responsive to the said signals for producing an output when the first signal and either of the second and third signals are present, and timing means responsive to the logic output for disabling the anti-lock control when the logic output is present for a predetermined time.
Claim 9
Dependent Claim
215 words
In an anti-lock brake control for a vehicle having a pair of braked non-driven wheels each equipped with a wheel speed sensor, a pair of braked driven wheels equipped with at least one wheel speed sensor, and a squaring amplifier responsive to each sensor for shaping the pulses therefrom, each squaring amplifier having a frequency output according to sensor output, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when the non-driven wheel squaring amplifier having the highest output exceeds a predetermined minimum value to produce a first signal indicating a minimum vehicle speed, means operative prior to the first brake release of an anti-lock brake control cycle for determining when the other non-driven wheel squaring amplifier output is substantially zero frequency to produce a second signal indicating a malfunction of the said other sensor, means for determining when a driven wheel squaring amplifier output is substantially zero frequency to produce a third signal indicating a malfunction of the said driven wheel sensor, logic means responsive to the said signals for producing an output when the first signal and either of the second and third signals are present, and timing means responsive to the logic output for disabling the anti-lock control when the logic output is present for a predetermined time.
Claim 10
Dependent Claim
215 words
In an anti-lock brake control for a vehicle having a pair of braked non-driven wheels each equipped with a wheel speed sensor, a pair of braked driven wheels equipped with at least one wheel speed sensor, and a squaring amplifier responsive to each sensor for shaping the pulses therefrom, each squaring amplifier having a frequency output according to sensor output, a failure monitoring circuit for detecting a sensor malfunction comprising means for determining when the non-driven wheel squaring amplifier having the highest output exceeds a predetermined minimum value to produce a first signal indicating a minimum vehicle speed, means operative prior to the first brake release of an anti-lock brake control cycle for determining when the other non-driven wheel squaring amplifier output is substantially zero frequency to produce a second signal indicating a malfunction of the said other sensor, means for determining when a driven wheel squaring amplifier output is substantially zero frequency to produce a third signal indicating a malfunction of the said driven wheel sensor, logic means responsive to the said signals for producing an output when the first signal and either of the second and third signals are present, and timing means responsive to the logic output for disabling the anti-lock control when the logic output is present for a predetermined time.
Claim 11
Dependent Claim
185 words
In a four wheel anti-lock brake control for a vehicle having a pair of non-driven braked front wheels each equipped with a wheel speed sensor and a pair of driven braked rear wheels equipped with at least one wheel sensor, a failure monitoring circuit comprising means for determining when one of the front wheel sensor outputs exceeds a predetermined minimum value to produce a first signal indicating a minimum vehicle speed, means operative prior to the first brake release of an anti-lock brake control cycle for determining when the other front wheel sensor output is substantially zero to produce a second signal indicating a malfunction of the said other sensor, means for determining when a rear wheel sensor output is substantially zero to produce a third signal indicating a malfunction of the rear wheel sensor or a very low rear wheel speed, and timing means responsive to the said signals for disabling the anti-lock control when the first and second signals are present for one time period and for disabling the anti-lock control when the first and third signals are present for another time period.
Claim 12
Dependent Claim
185 words
In a four wheel anti-lock brake control for a vehicle having a pair of non-driven braked front wheels each equipped with a wheel speed sensor and a pair of driven braked rear wheels equipped with at least one wheel sensor, a failure monitoring circuit comprising means for determining when one of the front wheel sensor outputs exceeds a predetermined minimum value to produce a first signal indicating a minimum vehicle speed, means operative prior to the first brake release of an anti-lock brake control cycle for determining when the other front wheel sensor output is substantially zero to produce a second signal indicating a malfunction of the said other sensor, means for determining when a rear wheel sensor output is substantially zero to produce a third signal indicating a malfunction of the rear wheel sensor or a very low rear wheel speed, and timing means responsive to the said signals for disabling the anti-lock control when the first and second signals are present for one time period and for disabling the anti-lock control when the first and third signals are present for another time period.
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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) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |