US4949078A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fail-safe operation of a vehicle automatic transmission responsive to failure of engine water temperature sensor
Assignee: Aisin AW Co Ltd
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Filing: 1988-12-09
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Granted: 1990-08-14
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Expires: 2008-12-09
Abstract
Abstract A fail-safe control device for an electronically controlled automatic transmission to be mounted on a vehicle arranged in such a manner that the number of engine revolution or the number of revolution input to a T/M is detected, the duration of the engine revolving state is counted, and it is determined that a failure of the engine water temperature sensor occurs if the engine water temperature detected by the engine water temperature sensor after a predetermined time elapse counted is lower than a predetermined temperature. As a result of this, a proper fail-safe control against the failure of the engine water temperature sensor can be performed.
Inventors
- 👤 Yasunobu Ito
- 👤 Kenji Suzuki
- 👤 Kazuhiro Mikami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:09
CPC Classifications
F; F16; F16H; F16H59/00; F16H59/74; F16H59/78; F16H61/00; F16H61/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
113 words
A fail-safe control device for an electronically controlled automatic transmission having a lock-up clutch comprising: (a) means for detecting the number (N E ) of engine revolutions or revolutions input to the transmission; (b) time counting means for measuring duration of engine operation after said number exceeds zero and generating a signal representative of counted time; (c) an engine water temperature sensor; and (d) means for receiving said signal and for determining that said engine water temperature sensor is in a failure state when the engine water temperature detected by said engine water temperature sensor, after said counted time exceeds a predetermined time, is lower than a temperature predetermined for said counted time.
Claim 2
Dependent Claim
113 words
A fail-safe control device for an electronically controlled automatic transmission having a lock-up clutch comprising: (a) means for detecting the number (N E ) of engine revolutions or revolutions input to the transmission; (b) time counting means for measuring duration of engine operation after said number exceeds zero and generating a signal representative of counted time; (c) an engine water temperature sensor; and (d) means for receiving said signal and for determining that said engine water temperature sensor is in a failure state when the engine water temperature detected by said engine water temperature sensor, after said counted time exceeds a predetermined time, is lower than a temperature predetermined for said counted time.
Claim 3
Dependent Claim
32 words
A fail-safe control device for an electronically controlled automatic transmission according to claim 1, wherein said failure of said engine water temperature sensor is displayed by operation of a failure alarm device.
Claim 4
Dependent Claim
45 words
The fail-safe control device of claim 1 further comprising: means for preventing operation of the lock-up clutch of the transmission and for preventing shifting to the maximum gear ratio of the transmission responsive to determination of the failure state of said engine water temperature sensor.
Claim 5
Dependent Claim
33 words
The fail-safe control device of claim 1 further comprising a failure alarm for notifying the driver of a failure of said engine water temperature sensor responsive to a determination of the failure state.
Claim 6
Dependent Claim
102 words
A fail-safe control method for an electronically controlled automatic transmission having a lock-up clutch, provided in a vehicle equipped with an engine water temperature sensor, said method comprising: (a) detecting the number (N E ) of engine revolutions or revolutions input to the transmission; (b) begin counting elapsed time when said number exceeds zero to obtain a counted elapsed time; and (c) determining that said engine water temperature sensor is in a failure state if the engine water temperature detected by the engine water temperature sensor, after a predetermined elapsed time, is lower than a temperature predetermined for said counted elapsed time.
Claim 7
Dependent Claim
102 words
A fail-safe control method for an electronically controlled automatic transmission having a lock-up clutch, provided in a vehicle equipped with an engine water temperature sensor, said method comprising: (a) detecting the number (N E ) of engine revolutions or revolutions input to the transmission; (b) begin counting elapsed time when said number exceeds zero to obtain a counted elapsed time; and (c) determining that said engine water temperature sensor is in a failure state if the engine water temperature detected by the engine water temperature sensor, after a predetermined elapsed time, is lower than a temperature predetermined for said counted elapsed time.
Claim 8
Dependent Claim
27 words
The fail-safe control method of claim 5 further comprising preventing operation of said lock-up clutch and shifting to maximum gear ratio upon determination of said failure state.
Claim 9
Dependent Claim
22 words
The fail-safe control method of claim 5 further comprising sounding an alarm to notify a driver of determination of said failure state.
References Cited (Backward Citations)
US3821562A
Cited
US4208929A
Cited
US4069712A
Cited
US4695822A
Cited
US4566354A
Cited
US4635034A
Cited
US4488140A
Cited
US4752883A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-13 | 1994-02-12 | 1994-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-13 | 1998-02-12 | 1998-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-13 | 2002-02-12 | 2002-08-14 | $7700.00 | Window Closed / Lapsed |