US3918488A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control valves for steering clutches and brakes
Assignee: Komatsu Ltd
•
Filing: 1973-11-06
•
Granted: 1975-11-11
•
Expires: 1993-11-06
Abstract
Abstract Controlling device of hydraulic system for steering which comprises providing pressure chambers connected to the fluid supplying ports on both end portions of spools built in a valve in such a manner that the orifice provided between one of said pressure chambers and drain port can be opened and closed by a solenoid valve; and connecting one of said pressure chambers to drain port by opening said orifice to generate pressure difference in said two pressure chambers to the effect that said spool can be operated.
Inventors
- 👤 Teruo Minami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:38
CPC Classifications
B; B62; B62D; B62D11/00; B62D11/02; B62D11/06; B62D11/08; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/16; B60T13/18; B60T13/66; B60T13/68; B60T13/686; F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/042; F15B13/043; F15B13/0431; F16; F16D; F16D67/00; F16D67/02; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/86582; Y10T137/86614; Y10T137/87169; Y10T137/87193; Y10T137/87209
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
192 words
A controlling device for a hydraulic system for steering, comprising a valve body, first and second parallel valve spools slidably aRranged within said body, first and second pilot valves affixed to said valve body, at least one feeding port, one outlet port and one drain port for each spool formed in the valve body and communicating with each of the first and second spools, first pressure chambers located respectively at the ends of the first spool and second pressure chambers located respectively at the ends of the second spool, an oil feeding restricted orifice and a feeding chamber within each spool connected between the first pressure chambers and between the second pressure chambers, said feeding chambers connected to said feeding ports by a feeding hole in each spool, springs contained in the pressure chambers on at least one end of each spool for continuously urging said spool toward its opposing pressure chamber, each of said chambers containing said spring being selectively connected to exhaust by one of said pilot valves whereby when one said pilot valve is opened, the pressure in the opposing pressure chamber moves the spool and compresses the spring.
Claim 2
Dependent Claim
192 words
A controlling device for a hydraulic system for steering, comprising a valve body, first and second parallel valve spools slidably aRranged within said body, first and second pilot valves affixed to said valve body, at least one feeding port, one outlet port and one drain port for each spool formed in the valve body and communicating with each of the first and second spools, first pressure chambers located respectively at the ends of the first spool and second pressure chambers located respectively at the ends of the second spool, an oil feeding restricted orifice and a feeding chamber within each spool connected between the first pressure chambers and between the second pressure chambers, said feeding chambers connected to said feeding ports by a feeding hole in each spool, springs contained in the pressure chambers on at least one end of each spool for continuously urging said spool toward its opposing pressure chamber, each of said chambers containing said spring being selectively connected to exhaust by one of said pilot valves whereby when one said pilot valve is opened, the pressure in the opposing pressure chamber moves the spool and compresses the spring.
Claim 3
Dependent Claim
38 words
A controlling device for a hydraulic system for a steering according to claim 1, wherein a pump is connected to said feeding ports, said springs are urged against spring sheet elements located between the respective springs and spools.
Claim 4
Dependent Claim
68 words
A controlling device for a hydraulic system for steering according to claim 1 wherein the pilot valves comprises solenoid valves and each contains a valve chamber with oil feeding apertures connecting said valve chamber with at least one of the respective pressure chambers for each spool, drain ports located in each solenoid valve, pistons located in said solenoid valve chambers and springs in contacting relation with each piston.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |