US3825307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means for detecting failure of various elements of an adaptive braking system through the use of trickle currents
Assignee: Bendix Corp
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Filing: 1973-04-13
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Granted: 1974-07-23
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Expires: 1993-04-13
Abstract
Abstract A circuit useful in adaptive braking systems for detecting sensor and load failures provides an operator warning and prevents automatic braking should a failure occur. Cross coupled comparators consider d.c. currents through the wheel speed sensors and interrupt electrical power to the braking system if a sensor is opened or shorted. A threshold circuit considers a trickle current through the brake pressure modulator to detect failures therein.
Inventors
- 👤 R Carr
- 👤 W Ingels
- 👤 L Ang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:12
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/32; B60T8/88; B60T8/885; B60T2270/00; B60T2270/40; B60T2270/402
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
220 words
Failure detection means for use in an adaptive braking system for wheeled vehicles including at least two sensors, each having a winding for generating an electrical signal proportional to a sensed vehicle wheel dynamic parameter, comprising: at least two constant current sources, one associated with each said sensor and respectively supplying a constant d.c. current to its associated sensor; at least first and second resistors, one associated with each said current source, said constant d.c. current being supplied to an associated sensor through an associated resistor; first means comparing the potential at one end of said first resistor with the potential at another end of said second resistor for generating a first signal if the potential at said another end exceeds the potential at said one end; a second comparator means comparing the potential at one end of said second resistor with the potential at another end of said first resistor for generating a second signal if the potential at said another end of said first resistor exceeds the potential at said one end of said second resistor; fiRst charge storage means for generating a utilization signal a predetermined time after said first signal has been continuously generated; and, a second charge storage means for generating said utilization signal a predetermined time after said second signal has been continuously generated.
Claim 2
Dependent Claim
220 words
Failure detection means for use in an adaptive braking system for wheeled vehicles including at least two sensors, each having a winding for generating an electrical signal proportional to a sensed vehicle wheel dynamic parameter, comprising: at least two constant current sources, one associated with each said sensor and respectively supplying a constant d.c. current to its associated sensor; at least first and second resistors, one associated with each said current source, said constant d.c. current being supplied to an associated sensor through an associated resistor; first means comparing the potential at one end of said first resistor with the potential at another end of said second resistor for generating a first signal if the potential at said another end exceeds the potential at said one end; a second comparator means comparing the potential at one end of said second resistor with the potential at another end of said first resistor for generating a second signal if the potential at said another end of said first resistor exceeds the potential at said one end of said second resistor; fiRst charge storage means for generating a utilization signal a predetermined time after said first signal has been continuously generated; and, a second charge storage means for generating said utilization signal a predetermined time after said second signal has been continuously generated.
Claim 3
Dependent Claim
46 words
Failure detection means as recited in claim 1 wherein said adaptive braking system is energized by a power source and including a utilization means responsive to said utilization signal for disconnecting said power source from said adaptive braking system whereby said adaptive braking system is inactivated.
Claim 4
Dependent Claim
57 words
Failure detection means as recited in claim 2 wherein said utilization means includes a silicone controlled rectifier means and a circuit breaker connected to energize power terminals whereby said adaptive braking system is energized, said silicone controlled rectifier means being responsive to said utilization signal for short circuiting said power terminals to thereby trip said circuit breaker.
Claim 5
Dependent Claim
34 words
Failure detection means as recited in claim 2 wherein said utilization means additionally includes indicator means responsive to said utilization signal for providing an indication of adaptive braking system failure to a vehicle operator.
Claim 6
Dependent Claim
121 words
The failure detection means of claim 1 wherein said adaptive braking system additionally includes at least one brake pressure modulator including a winding for controlling brake pressure in response to control signals, said failure detection means additionally comprising; a power source having first and second terminals; means connecting one end of the modulator winding to said first terminal; switch means responsive to said control signals for switchably connecting the second end of said modulator winding to said second terminal; resistive means shunting said switch means whereby a trickle current flows in said modulator winding and said resistive means; means sensing the trickle current through said resistive means and responsive to the absence of said trickle current for generating said second signal.
Claim 7
Dependent Claim
106 words
The failure detector of claim 5 wherein said first charge storage means comprises a time constant circuit including a capacitor, said time constant circuit being responsive to said first signal for accumulating charges and including a threshold circuit for generating said utilization signal when the voltage across said capacitor exceeds a predetermined threshold; and wherein said second charge storage means comprises a second time constant circuit including a second capacitor, said second time constant means being responsive to said second signal for accumulating charges and including a second threshold circuit for generating said utilization signal when the voltage across said second capacitor exceeds said predetermined threshold.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |