Patent US4730709A successfully refreshed from Google Patents.
US4730709A
Expired / Lapsed
US
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Lockup clutch control system
Assignee: Aisin Corp
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Filing: 1986-07-30
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Granted: 1988-03-15
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Expires: 2006-07-30
Abstract
Abstract A lockup clutch in a torque converter is connected by a lockup solenoid energized in response to a lockup signal generated by a lockup discrimination circuit. When a speed sensor detects a rate of deceleration higher than a predetermined level at the time the vehicle is abruptly braked, for example, a lockup control circuit overrides the lockup discrimination circuit to cut off the lockup signal for thereby de-energizing the lockup solenoid, whereupon the lockup clutch is disconnected.
Inventors
- 👤 Shoji Kawata
- 👤 Tsuyoshi Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:22
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/14; F16H61/143; B; B60; B60W; B60W2520/00; B60W2520/10; B60W2520/105; F16H59/00; F16H59/36; F16H59/38; F16H2059/405; F16H59/48
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
172 words
A lockup clutch control system for use on a vehicle of the type having a torque converter including input and output shafts and a lockup clutch for directly connecting said input and output shafts of said torque converter, said system comprising: lockup discrimination circuit means for generating a lockup signal; a lockup solenoid for actuating said lockup clutch in response to said lockup signal; a speed sensor for detecting the speed of the vehicle; deceleration detecting circuit means for detecting the deceleration of the vehicle based on a signal from said speed sensor; and discriminator circuit means for de-energizing said lockup solenoid for at least a minimum interval of time in response to detection by said detecting circuit means of a rate of deceleration higher than a predetermined level, wherein said minimum interval of time is substantially independent of the vehicle speed subsequent to de-energizing said lockup solenoid and is determined by said detecting circuit means which also determines the rate of deceleration at which said lockup clutch is to be released.
Claim 2
Dependent Claim
172 words
A lockup clutch control system for use on a vehicle of the type having a torque converter including input and output shafts and a lockup clutch for directly connecting said input and output shafts of said torque converter, said system comprising: lockup discrimination circuit means for generating a lockup signal; a lockup solenoid for actuating said lockup clutch in response to said lockup signal; a speed sensor for detecting the speed of the vehicle; deceleration detecting circuit means for detecting the deceleration of the vehicle based on a signal from said speed sensor; and discriminator circuit means for de-energizing said lockup solenoid for at least a minimum interval of time in response to detection by said detecting circuit means of a rate of deceleration higher than a predetermined level, wherein said minimum interval of time is substantially independent of the vehicle speed subsequent to de-energizing said lockup solenoid and is determined by said detecting circuit means which also determines the rate of deceleration at which said lockup clutch is to be released.
Claim 3
Dependent Claim
33 words
A lockup clutch control system according to claim 1, wherein said discriminator circuit means includes means for cutting off a power supply line connected to said lockup solenoid, thereby de-energizing said lockup solenoid.
Claim 4
Dependent Claim
34 words
A lockup clutch control system according to claim 1, wherein said discriminator circuit means includes means for overriding said lockup discrimination circuit means to cut off said lockup signal, thereby de-energizing said lockup solenoid.
Claim 5
Dependent Claim
44 words
A lockup clutch control system according to claim 1 wherein said detecting circuit means includes converter means for converting said signal from said speed sensor into a voltage and capacitor and resistor means for differentiating said voltage to detect the deceleration of the vehicle.
Claim 6
Dependent Claim
42 words
A lockup clutch control system according to claim 1, wherein said detecting circuit means includes means for determining said minimum interval of time for which said lockup solenoid is de-energized in accordance with the rate of deceleration detected by said detecting circuit.
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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) | 1991-03-15 | 1991-09-14 | 1992-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-15 | 1995-09-14 | 1996-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-15 | 1999-09-14 | 2000-03-15 | $7700.00 | Window Closed / Lapsed |