US3923076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission control system with dual purpose modulating valve
Assignee: Caterpillar Inc
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Filing: 1975-01-08
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Granted: 1975-12-02
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Expires: 1995-01-08
Abstract
Abstract A hydraulic transmission control circuit having selector valves for communicating fluid at a first pressure to selected speed ratio clutches and for communicating fluid at a second pressure to directional clutches capable of acting as master clutches, a first modulating valve for modulating the first fluid pressure and a differential valve for establishing the second fluid pressure relative to the first fluid pressure, the control circuit also including a manually controlled modulating valve having a modulating spool which is manually operable for selectively modulating the second fluid pressure in two discreet operating modes in order to provide more precise regulation over clutch engagement under different operating conditions, the manually controlled modulating valve also including relief means for selectively reducing the first fluid pressure during regulation of the second fluid pressure by the manually controlled modulating valve.
Inventors
- 👤 William Wayne Blake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:01
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/02; F16H61/0262; F16H61/0265; F16H61/0272; F16H61/70; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781; Y10T137/7782; Y10T137/8593; Y10T137/87153
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
204 words
A manual modulating valve for a hydraulic control circuit of the type having a first conduit with first modulating means for establishing the first fluid pressure within the first conduit, a second fluid conduit and differential means for establishing a second fluid pressure within the second conduit differentially related to the first fluid pressure, the manual modulating valve comprising, a valve body defining a bore, an inlet passage communicating the second conduit with the bore and an outlet passage also in communication with the bore, a modulating spool movably arranged within the bore to regulate fluid communication between the inlet and outlet passages of the valve body, and a manually adjustable metering spool movably arranged within the bore for interaction with the modulating spool through resilient means, the valve body forming an additional inlet passage for communicating the first conduit with the bore adjacent the manually adjustable metering spool, the manually adjustable metering spool being movable for causing the modulating spool to regulate fluid communication between the inlet and outlet passages, the manually adjustable metering spool simultaneously communicating the additional inlet to a fluid drain in order to selectively reduce the first fluid pressure within the first conduit during operation of the modulating spool.
Claim 2
Dependent Claim
204 words
A manual modulating valve for a hydraulic control circuit of the type having a first conduit with first modulating means for establishing the first fluid pressure within the first conduit, a second fluid conduit and differential means for establishing a second fluid pressure within the second conduit differentially related to the first fluid pressure, the manual modulating valve comprising, a valve body defining a bore, an inlet passage communicating the second conduit with the bore and an outlet passage also in communication with the bore, a modulating spool movably arranged within the bore to regulate fluid communication between the inlet and outlet passages of the valve body, and a manually adjustable metering spool movably arranged within the bore for interaction with the modulating spool through resilient means, the valve body forming an additional inlet passage for communicating the first conduit with the bore adjacent the manually adjustable metering spool, the manually adjustable metering spool being movable for causing the modulating spool to regulate fluid communication between the inlet and outlet passages, the manually adjustable metering spool simultaneously communicating the additional inlet to a fluid drain in order to selectively reduce the first fluid pressure within the first conduit during operation of the modulating spool.
Claim 3
Dependent Claim
65 words
The manual modulating valve of claim 1 wherein the modulating spool forms a chamber in communication with the inlet, fluid pressure within the chamber causing the spool to act as a modulating reducing valve, the manual modulating valve further comprising means for selectively communicating the chamber formed by the modulating spool with a fluid drain in response to movement of the manually adjustable metering spool.
Claim 4
Dependent Claim
26 words
The manual modulating valve of claim 2 further comprising a second resilient means arranged for interaction between the manually adjustable metering spool and the modulating spool.
Claim 5
Dependent Claim
51 words
The manual modulating valve of claim 1 further comprising a second resilient means arranged for interaction between the manually adjustable metering spool and the modulating spool. The second resilient means interacting between the manually adjustable metering spool and the modulating spool only during initial movement of the manually adjustable metering spool.
References Cited (Backward Citations)
US3137311A
Cited
US3468194A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |