US4466502A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for controlling transmission torque of a four-wheel drive vehicle
Assignee: Subaru Corp
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Filing: 1982-09-27
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Granted: 1984-08-21
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Expires: 2002-09-27
Abstract
Abstract A system for a four-wheel drive vehicle for automatically changing transmission torque to rear wheels. The system is provided with a fluid pressure controlled friction clutch which is in a partial engagement state in an ordinary driving condition for transmitting the power of the engine to rear wheels. Therefore, when the vehicle turns a corner, the friction clutch slips to allow the rear wheels to rotate slower than front wheels. A load sensor and slip detecting device are provided for producing signals. A control system is provided to respond to the signals for increasing the engagement part of the friction clutch to provide a sufficient four-wheel driving.
Inventors
- 👤 Yasuhito Sakai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:53
CPC Classifications
B; B60; B60K; B60K23/00; B60K23/08; B60K23/0808
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
139 words
A system for controlling a transmission torque of a four-wheel drive vehicle powered by an engine comprising: a transmission for operatively transmitting a power of said engine to front wheels; a friction clutch for transmitting said power to rear wheels; clutch operating means for engaging and disengaging said friction clutch, said clutch operating means comprising a first means for providing a partial engagement of the clutch, a second means for providing an engagement greater than said partial engagement, and a third means for disengaging said clutch; slip detecting means for detecting the slipping of wheels; load detecting means for detecting the load on said engine; control means responsive to signals from said slip detecting means and load detecting means for operating said second means so as to engage said clutch at heavy load and at the slipping of wheels.
Claim 2
Independent Claim
139 words
A system for controlling a transmission torque of a four-wheel drive vehicle powered by an engine comprising: a transmission for operatively transmitting a power of said engine to front wheels; a friction clutch for transmitting said power to rear wheels; clutch operating means for engaging and disengaging said friction clutch, said clutch operating means comprising a first means for providing a partial engagement of the clutch, a second means for providing an engagement greater than said partial engagement, and a third means for disengaging said clutch; slip detecting means for detecting the slipping of wheels; load detecting means for detecting the load on said engine; control means responsive to signals from said slip detecting means and load detecting means for operating said second means so as to engage said clutch at heavy load and at the slipping of wheels.
Claim 3
Dependent Claim
16 words
The system according to claim 1 further comprising a manual switch for operating said third means.
Claim 4
Dependent Claim
22 words
The system according to claim 1 wherein said friction clutch is a fluid pressure controlled friction clutch of the type of multiple-disk.
Claim 5
Dependent Claim
32 words
The system according to claim 3 wherein said control means comprises a pressure oil supply circuit including solenoid valves for operating said clutch and an electric circuit for operating the solenoid valves.
References Cited (Backward Citations)
JPS56138019A
Cited
US4417641A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-08-21 | 1988-02-20 | 1988-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-21 | 1992-02-20 | 1992-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-21 | 1996-02-20 | 1996-08-21 | $7700.00 | Window Closed / Lapsed |