Patent US3830258A successfully refreshed from Google Patents.
US3830258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission control mechanism
Assignee: BorgWarner Ltd
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Filing: 1972-08-21
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Granted: 1974-08-20
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Expires: 1992-08-21
Abstract
Abstract A hydraulic control system for an automatic transmission providing four forward drive ratios by selective engagement of friction-engaging devices and including a shift valve for each of the shifts between drive ratios, valve means producing a first pressure responsive to vehicle speed and valve means producing a second pressure responsive to engine load and throttle position, said pressures each influencing said shift valves to determine the shift points of the transmission, and further including an exhaust valve means for each of two friction elements, said exhaust valve means being responsive to said pressures to control exhaust of pressure from said friction elements when the transmission is upshifted. The control system further includes timing valve means responsive to said first pressure to control the rate of engagement of said friction devices when the transmission is downshifting between ratios and accumulator means responsive to each of said pressures to further control the rate of engagement of sad friction devices.
Inventors
- 👤 M Leach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:17
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/02; F16H61/0262; F16H61/0265; F16H61/0267; B; B60; B60K; B60K2702/00; B60K2702/02; B60K2702/04; F16H61/04; F16H61/06; F16H61/065; F16H61/08; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86879
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
215 words
A hydraulic control system for an automatic transmission including a source of fluid pressure and a manual selector valve having a plurality of ports for distributing pressure from said source of said control system, said manual valve having a first port for receiving pressure from said source and a second port connected to said control system, said manual valve including s spool having slots for providing desired connections between said ports of said valve, said manual valve having a plurality of forward positions including an automatic ratio changing position and additional selective positions in which said manual valve is adapted to select particular drive ratios in the transmission, said manual valve providing a fluid connection between said first and second ports in the forward positions of said manual valve, a third port on said manual valve in fluid communication with said second port whereby when said second port is pressurized said third port is also pressurized, said second and third ports being on opposite sides of said first port, and said third port acting as a pressure signal port to condition said control system to establish said particular drive ratios for all said additional selective positions of said manual valve and said first, second and third ports being on the same side of said valve.
Claim 2
Dependent Claim
215 words
A hydraulic control system for an automatic transmission including a source of fluid pressure and a manual selector valve having a plurality of ports for distributing pressure from said source of said control system, said manual valve having a first port for receiving pressure from said source and a second port connected to said control system, said manual valve including s spool having slots for providing desired connections between said ports of said valve, said manual valve having a plurality of forward positions including an automatic ratio changing position and additional selective positions in which said manual valve is adapted to select particular drive ratios in the transmission, said manual valve providing a fluid connection between said first and second ports in the forward positions of said manual valve, a third port on said manual valve in fluid communication with said second port whereby when said second port is pressurized said third port is also pressurized, said second and third ports being on opposite sides of said first port, and said third port acting as a pressure signal port to condition said control system to establish said particular drive ratios for all said additional selective positions of said manual valve and said first, second and third ports being on the same side of said valve.
Claim 3
Dependent Claim
80 words
A control system as claimed in claim 1, wherein said valve spool has at least one slot extending through said spool, additional ports on said manual valve adapted to supply pressure signals to said transmission to establish said particular drive ratios and certain of said additional ports being on the other side of said spool whereby certain of said fluid connections from said pressure signal port are made through said spool for said additional selected positions of said manual valve.
Claim 4
Dependent Claim
13 words
A control system as claimed in claim 1 wherein said spool is non-rotatable.
References Cited (Backward Citations)
US986092A
Cited
US2636566A
Cited
US2887893A
Cited
US2972984A
Cited
US3293934A
Cited
US3295387A
Cited
US3473571A
Cited
US3568718A
Cited
US3626966A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |