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Patent US4016457A successfully refreshed from Google Patents.
US4016457A
Expired / Lapsed
US
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Failsafe system for skid control systems and the like
Assignee: ZF Active Safety US Inc
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Filing: 1975-04-10
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Granted: 1977-04-05
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Expires: 1995-04-10
Abstract
Abstract A failsafe system for a skid control system for a multi-axle wheeled vehicle. The skid control system has a plurality of skid control modules, each of which is operatively associated with one of the axles of the vehicle and the skid control modules are operatively coupled by wiring on the vehicle. Each skid control module comprises a skid control circuit for skid controlling the wheels of the associated axle, which circuit is supplied from an electrical power source such as the vehicle battery, either regulated or unregulated. A failsafe circuit is provided in each skid control module and the failsafe circuits of the several modules are connected in cascade fashion to form a chain. An input signal is supplied to the input of the first of the cascaded failsafe circuits and can propagate through the chain of failsafe circuits to the output of the last failsafe circuit only if wiring connecting the modules is proper, the failsafe circuits themselves are operating properly, and electrical power is supplied to each module. A warning occurs when the signal fails to propagate through all the failsafe circuits, and this indicates loss of power or a fault in the modules or the wiring connecting the modules.
Inventors
- 👤 John S. Frait
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:34
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/005; G01R31/006; B; B60; B60T; B60T8/00; B60T8/32; B60T8/88; B60T8/885; B60T2270/00; B60T2270/40; B60T2270/414
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
212 words
A failsafe circuit means comprising an input terminal, an output terminal, and a pair of supply terminals for respectively receiving from a single source a supply potential and a ground potential, means forming an input circuit operatively coupled with said input terminal and one of said pair of supply terminals, means forming an output circuit operatively coupled with said output terminal and the other of said pair of supply terminals, said input circuit comprising first normally conductive electronic switch means that is rendered non-conductive in response to the absence of either an input signal normally applied to said input terminal or the respective potential normally present at said one supply terminal, said output circuit means comprising a second normally conductive electronic switch means and a voltage dividing means, means operatively coupling said input circuit and said output circuit such that said second electronic switch means is rendered non-conductive whenever either said first electronic switch means is rendered nonconductive or in response to the absence of the respective potential normally present at said other supply terminal, said voltage dividing means being operatively coupled with said output terminal for supplying at said output terminal an output signal which is a fraction of said supply potential whenever both of said electronic switch means are conducting.
Claim 2
Dependent Claim
212 words
A failsafe circuit means comprising an input terminal, an output terminal, and a pair of supply terminals for respectively receiving from a single source a supply potential and a ground potential, means forming an input circuit operatively coupled with said input terminal and one of said pair of supply terminals, means forming an output circuit operatively coupled with said output terminal and the other of said pair of supply terminals, said input circuit comprising first normally conductive electronic switch means that is rendered non-conductive in response to the absence of either an input signal normally applied to said input terminal or the respective potential normally present at said one supply terminal, said output circuit means comprising a second normally conductive electronic switch means and a voltage dividing means, means operatively coupling said input circuit and said output circuit such that said second electronic switch means is rendered non-conductive whenever either said first electronic switch means is rendered nonconductive or in response to the absence of the respective potential normally present at said other supply terminal, said voltage dividing means being operatively coupled with said output terminal for supplying at said output terminal an output signal which is a fraction of said supply potential whenever both of said electronic switch means are conducting.
Claim 3
Dependent Claim
36 words
A failsafe circuit means according to claim 1 wherein said voltage dividing means comprises a pair of resistors connected in series with the connection of said pair of resistors being operatively coupled to said output terminal.
Claim 4
Dependent Claim
21 words
A failsafe circuit means according to claim 1 wherein said voltage divider is connected in series with said second switch means.
Claim 5
Dependent Claim
71 words
A failsafe circuit means according to claim 1 wherein said first switch means has a control terminal and two output terminals with said control terminal operatively coupled with said input terminal and with at least one of said output terminals operatively coupled with said second switch means so that when said first switch means is actuated in response to said input signal said first switch means actuates said second switch means.
Claim 6
Dependent Claim
114 words
A failsafe circuit means according to claim 4 wherein said second switch means has a control terminal and two output terminals with said control terminal being operatively coupled with said one output terminal of said first switch means to provide a signal from said one output terminal of said first switch means to said control terminal of said second switch means to actuate said second switch means upon actuation of said first switch means and with one of said output terminals of said second switch means being operatively coupled with said voltage dividing mens for substantially full application of said supply potential across said voltage dividing means upon actuation of said second switch means.
Claim 7
Dependent Claim
48 words
A failsafe circuit means according to claim 5 wherein the other of said output terminals of said first switch means is operatively coupled to said one supply terminal and the other of said output terminals of said second switch means is operatively coupled to said other supply terminal.
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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) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |