US3690197A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic transmission
Assignee: Denso Corp
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Filing: 1970-06-12
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Granted: 1972-09-12
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Expires: 1990-06-12
Abstract
Abstract An automatic transmission for use in cars in combination with a torque-converter, gear transmission mechanism and frictional coupling means for establishing a required gear meshing relation of said gear transmission mechanism, said frictional coupling means being actuated by working oil supplied through a hydraulically actuating circuit including a regulating valve adapted to vary the pressure of said working oil, wherein said regulating valve is actuated to reduce the pressure of the working oil in response to a predetermined slip ratio of said torque-converter and/or a predetermined gear position of said transmission mechanism and/or a predetermined car-speed so that an impact due to variation of torque to be transmitted is eliminated.
Inventors
- 👤 Masaharu Sumiyoshi
- 👤 Shigeru Sakakibara
- 👤 Hisato Wakamatsu
- 👤 Takaaki Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:19
CPC Classifications
F; F16; F16H; F16H47/00; F16H47/06; F16H47/08; F16H61/00; F16H61/0021; F16H59/00; F16H59/36; F16H59/46; F16H2059/465; F16H2059/467; F16H61/02; F16H61/0202; F16H61/0251; F16H2061/026
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
233 words
An automatic transmission comprising a torque-converter; a gear transmission mechanism having an output shaft; frictional coupling means requiring working oil for drivingly connecting said mechanism to said torque-converter to establish any one of a plurality of gear meshing relations required of said gear transmission mechanism; a hydraulic actuating circuit including distribution valve means for selectively distributing said working oil to said frictional coupling means to cause selection of a required one of said gear meshing relations; an electrical control unit including slip ratio detecting circuit means for detecting slip ratio of said torque-converter, gear position discriminating circuit means for determining said required gear meshing relation of said gear transmission mechanism, rotational speed detecting circuit means for detecting the rotational speed of the said output shaft of said gear transmission mechanism, and gear shifting operational circuit means for controlling said distribution valve means in accordance with outputs from said slip ratio detecting circuit means, from said gear position discriminating circuit means and from said rotational speed detecting circuit means to control which of said gear meshing relations is selected as aforesaid, said hydraulic actuating circuit further including regulating valve means actuated in response to the slip ratio detecting circuit means output generated when the slip ratio of said torque-converter becomes higher than a predetermined value for reducing the pressure of the working oil distributed to said frictional coupling means through said distribution valve means.
Claim 2
Dependent Claim
233 words
An automatic transmission comprising a torque-converter; a gear transmission mechanism having an output shaft; frictional coupling means requiring working oil for drivingly connecting said mechanism to said torque-converter to establish any one of a plurality of gear meshing relations required of said gear transmission mechanism; a hydraulic actuating circuit including distribution valve means for selectively distributing said working oil to said frictional coupling means to cause selection of a required one of said gear meshing relations; an electrical control unit including slip ratio detecting circuit means for detecting slip ratio of said torque-converter, gear position discriminating circuit means for determining said required gear meshing relation of said gear transmission mechanism, rotational speed detecting circuit means for detecting the rotational speed of the said output shaft of said gear transmission mechanism, and gear shifting operational circuit means for controlling said distribution valve means in accordance with outputs from said slip ratio detecting circuit means, from said gear position discriminating circuit means and from said rotational speed detecting circuit means to control which of said gear meshing relations is selected as aforesaid, said hydraulic actuating circuit further including regulating valve means actuated in response to the slip ratio detecting circuit means output generated when the slip ratio of said torque-converter becomes higher than a predetermined value for reducing the pressure of the working oil distributed to said frictional coupling means through said distribution valve means.
Claim 3
Dependent Claim
73 words
An automatic transmission as in claim 1, wherein said electrical control unit further includes AND gate means connected to said slip ratio detecting circuit means and to said gear position discriminating circuit means for generating an output signal when the slip ratio of said torque-converter becomes higher than a predetermined value at a predetermined gear position, said regulating valve means being actuated in response to said output signal of said AND gate means.
Claim 4
Dependent Claim
109 words
An automatic transmission as in claim 1 wherein said electrical control unit further includes AND gate means and OR gate means, said AND gate means being connected to said slip ratio detecting circuit means and to said rotational speed detecting circuit means through said OR gate means and to said gear position discriminating circuit means for actuating said regulating valve means to reduce said working oil pressure by generating an output signal when the slip ratio of said torque-converter becomes higher than said predetermined value or the rotational speed of the output shaft of said gear transmission mechanism is less than a predetermined speed at a predetermined gear position.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |