US3710649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic control device for automatic transmission
Assignee: Toyota Motor Corp
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Filing: 1971-02-02
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Granted: 1973-01-16
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Expires: 1991-02-02
Abstract
Abstract A hydraulic pressure control device is provided for an automatic transmission including a hydraulic torque-converter or fluid coupling, a change speed gearing, a hydraulic servo for brake bands, clutches and the like. A relay valve is added to a pressure regulator valve for controlling the hydraulic pressure applied to the servo, and in response to the actuation of an automatic shift valve an oil line to the servo is communicated with a pressure control chamber in the pressure regulator valve so that the pressure regulating function of the pressure regulator valve may be varied depending upon the position of a manual valve and also depending upon the actuation of the automatic shift valve. The hydraulic circuit may be simplified.
Inventors
- 👤 S Kubo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:19
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/0021
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
288 words
In a hydraulic pressure control device for use in an automatic transmission of the type including a fluid torqueconverter or fluid coupling and a transmission provided with hydraulic servo means for brake bands, clutches and the like which carry out an automatic speed change: an oil pump for generating the hydraulic pressure to be supplied to said hydraulic servo means, a pressure regulator valve for controlling the hydraulic pressure to be applied to said hydraulic servo, said pressure regulator valve having an oil pressure chamber formed therein for controlling said hydraulic pressure, a manual valve having at least two positions, a relay valve for supplying a required hydraulic pressure to said oil pressure chamber in said pressure regulator valve, a first conduit for communicating said oil pump with said relay valve when said manual valve is in one position, and a second conduit for communicating said oil pump with said relay valve through said manual valve when said manual valve is in another position, said relay valve having a movable valve element and a spring urging said valve element, said relay valve supplying a reduced hydraulic pressure to said oil pressure chamber in said pressure regulator valve when said manual valve is in one position which reduced pressure is equal to the hydraulic pressure supplied from said first conduit minus the pressure corresponding to the force of said spring, while when said manual valve is in another position said relay valve supplying the hydraulic pressure supplied from said second conduit and being subjected to no regulation to said oil pressure chamber in said pressure regulator valve, and the hydraulic pressure control operation of said pressure regulator valve being varied in response to the positions of said manual valve.
Claim 2
Dependent Claim
288 words
In a hydraulic pressure control device for use in an automatic transmission of the type including a fluid torqueconverter or fluid coupling and a transmission provided with hydraulic servo means for brake bands, clutches and the like which carry out an automatic speed change: an oil pump for generating the hydraulic pressure to be supplied to said hydraulic servo means, a pressure regulator valve for controlling the hydraulic pressure to be applied to said hydraulic servo, said pressure regulator valve having an oil pressure chamber formed therein for controlling said hydraulic pressure, a manual valve having at least two positions, a relay valve for supplying a required hydraulic pressure to said oil pressure chamber in said pressure regulator valve, a first conduit for communicating said oil pump with said relay valve when said manual valve is in one position, and a second conduit for communicating said oil pump with said relay valve through said manual valve when said manual valve is in another position, said relay valve having a movable valve element and a spring urging said valve element, said relay valve supplying a reduced hydraulic pressure to said oil pressure chamber in said pressure regulator valve when said manual valve is in one position which reduced pressure is equal to the hydraulic pressure supplied from said first conduit minus the pressure corresponding to the force of said spring, while when said manual valve is in another position said relay valve supplying the hydraulic pressure supplied from said second conduit and being subjected to no regulation to said oil pressure chamber in said pressure regulator valve, and the hydraulic pressure control operation of said pressure regulator valve being varied in response to the positions of said manual valve.
Claim 3
Dependent Claim
144 words
A hydraulic pressure control device for use in an automatic transmission as defined in claim 1 characterized by further including a second oil pressure chamber formed in said pressure regulator valve for controlling the hydraulic pressure to be supplied to said hydraulic servo means, an electrically operated automatic shift valve activated in response to a transmission actuation signal for selectively supplying to and discharging from said hydraulic servo means the hydraulic pressure thereby establishing a low-speed forward-drive ratio and a high-speed forward-drive ratio, and a third conduit for communicating the conduit for supplying the hydraulic pressure from said automatic shift valve to said hydraulic servo means with said second oil pressure chamber in said pressure regulator valve, the control operation of said pressure regulator valve being varied in response to the position of said manual valve and the actuation of said automatic shift valve.
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) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |