US3882980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission control system with dual purpose modulating
Assignee: Caterpillar Inc
•
Filing: 1973-04-27
•
Granted: 1975-05-13
•
Expires: 1993-04-27
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 15:20
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/02; F16H61/0262; F16H61/0265; F16H61/0272; F16H61/70; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/87153; Y10T137/87161
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
299 words
A hydraulic transmission control circuit for selectively actuating at least one of a plurality of speed ratio clutches with hydraulic fluid at a first pressure and for selectively actuating one of a plurality of directional clutches at a second differential pressure, comprising a fluid source, a speed ratio selector valve means for communicating fluid at the first pressure to one of the speed ratio clutches, a directional selector valve for communicating fluid at the second differential pressure to one of the directional clutches, a differential valve in communication with the fluid source, the differential valve including means to communicate hydraulic fluid at the second differential pressure to the directional selector valve, a first pressure modulating valve in communication with the source and the differential valve for modulating hydraulic fluid at the first pressure, and a manually controlled modulating valve arranged to communicate fluid at the second differential pressure from the differential valve to the directional selector valve, the manually controlled modulating valve including means for selectively modulating the second differential pressure in two discreet operating modes in order to provide more precise regulation of clutch engagement under different operating conditions, said two discreet operating modes being characterized by the selective modulating means in the manual modulating valve being operable to vary the second differential pressure at two different rates of modulation in order to selectively regulate the degree of engagement in the directional clutches, the selective modulating means in the manual modulating valve comprising a modulating valve spool and first and second resilient means arranged for operative interaction between the modulating valve spool and a manually adjustable element, the first and second resilient means having different spring characteristics for acting in unison and singly in order to vary the second differential pressure at two distinctly different rates of modulation.
Claim 2
Dependent Claim
299 words
A hydraulic transmission control circuit for selectively actuating at least one of a plurality of speed ratio clutches with hydraulic fluid at a first pressure and for selectively actuating one of a plurality of directional clutches at a second differential pressure, comprising a fluid source, a speed ratio selector valve means for communicating fluid at the first pressure to one of the speed ratio clutches, a directional selector valve for communicating fluid at the second differential pressure to one of the directional clutches, a differential valve in communication with the fluid source, the differential valve including means to communicate hydraulic fluid at the second differential pressure to the directional selector valve, a first pressure modulating valve in communication with the source and the differential valve for modulating hydraulic fluid at the first pressure, and a manually controlled modulating valve arranged to communicate fluid at the second differential pressure from the differential valve to the directional selector valve, the manually controlled modulating valve including means for selectively modulating the second differential pressure in two discreet operating modes in order to provide more precise regulation of clutch engagement under different operating conditions, said two discreet operating modes being characterized by the selective modulating means in the manual modulating valve being operable to vary the second differential pressure at two different rates of modulation in order to selectively regulate the degree of engagement in the directional clutches, the selective modulating means in the manual modulating valve comprising a modulating valve spool and first and second resilient means arranged for operative interaction between the modulating valve spool and a manually adjustable element, the first and second resilient means having different spring characteristics for acting in unison and singly in order to vary the second differential pressure at two distinctly different rates of modulation.
Claim 3
Dependent Claim
37 words
The control circuit of claim 1 wherein the speed ratio selector valve includes means to communicate fluid at the first pressure to a selected speed ratio clutch and a selected range clutch for establishing a speed ratio.
Claim 4
Dependent Claim
51 words
The control circuit of claim 1 wherein the manually controlled modulating valve further comprises relief means in operative communication with the first pressure modulating valve to selectively reduce the first fluid pressure during operation of the modulating valve spool by the manually adjustable element through the first and second resilient means.
Claim 5
Dependent Claim
272 words
A hydraulic transmission control circuit for selectively actuating at least one of a plurality of speed ratio clutches with hydraulic fluid at a first pressure and for selectively actuating one of a plurality of directional clutches at a second differential pressure, comprising a fluid source, a speed ratio selector valve means for communicating fluid at the first pressure to one of the speed ratio clutches, a directional selector valve for communicating fluid at the second differential pressure to one Of the directional clutches, a differential valve in communication with the fluid source, the differential valve including means to communicate hydraulic fluid at the second differential pressure to the directional selector valve, a first pressure modulating valve in communication with the source and the differential valve for modulating hydraulic fluid at the first pressure, and a manually controlled modulating valve arranged to communicate fluid at the differential pressure from the differential valve to the directional selector valve, the manually controlled modulating valve including means for selectively modulating the second differential pressure in two discreet operating modes in order to provide more precise regulating of clutch engagement under different operating conditions, said two discreet operating modes being characterized by the selective modulating means in the manual modulating valve being operable to vary the second differential pressure at two different rates of modulation in order to selectively regulate the degree of engagement in the directional clutches, the manually controlled modulating valve further comprising relief means in operative communication with the first pressure modulating valve to selectively reduce the first fluid pressure during selective modulation of the second differential pressure by the manually controlled modulating valve.
Claim 6
Dependent Claim
272 words
A hydraulic transmission control circuit for selectively actuating at least one of a plurality of speed ratio clutches with hydraulic fluid at a first pressure and for selectively actuating one of a plurality of directional clutches at a second differential pressure, comprising a fluid source, a speed ratio selector valve means for communicating fluid at the first pressure to one of the speed ratio clutches, a directional selector valve for communicating fluid at the second differential pressure to one Of the directional clutches, a differential valve in communication with the fluid source, the differential valve including means to communicate hydraulic fluid at the second differential pressure to the directional selector valve, a first pressure modulating valve in communication with the source and the differential valve for modulating hydraulic fluid at the first pressure, and a manually controlled modulating valve arranged to communicate fluid at the differential pressure from the differential valve to the directional selector valve, the manually controlled modulating valve including means for selectively modulating the second differential pressure in two discreet operating modes in order to provide more precise regulating of clutch engagement under different operating conditions, said two discreet operating modes being characterized by the selective modulating means in the manual modulating valve being operable to vary the second differential pressure at two different rates of modulation in order to selectively regulate the degree of engagement in the directional clutches, the manually controlled modulating valve further comprising relief means in operative communication with the first pressure modulating valve to selectively reduce the first fluid pressure during selective modulation of the second differential pressure by the manually controlled modulating valve.
Claim 7
Dependent Claim
212 words
A hydraulic transmission control circuit for selectively actuating at least one of a plurality of speed ratio clutches with hydraulic fluid at a first modulated pressure and for selectively actuating one of a plurality of directional clutches with hydraulic fluid at a second pressure differentially related to the first pressure, comprising, a fluid source, a speed ratio selector valve means for communicating fluid at the first pressure to one of the speed ratio clutches, a directional selector valve for communicating fluid at the second pressure to one of the directional clutches, a first modulating valve in communication with the source and the speed ratio selector valve means for modulating fluid at the first pressure, a differential valve in communication with the fluid source, the first modulating valve and the directional selector valve, the differential valve including means to differentially establish the second pressure for communication to the directional selector valve, and a second modulating valve including manually adjustable modulating means for communicating fluid at the second pressure from the differential valve to the directional selector valve at a regulated rate, the second modulating valve further including relief means in operative communication with the first pressure modulating valve to selectively reduce the first fluid pressure during operation of the manually adjustable modulating means.
Claim 8
Dependent Claim
212 words
A hydraulic transmission control circuit for selectively actuating at least one of a plurality of speed ratio clutches with hydraulic fluid at a first modulated pressure and for selectively actuating one of a plurality of directional clutches with hydraulic fluid at a second pressure differentially related to the first pressure, comprising, a fluid source, a speed ratio selector valve means for communicating fluid at the first pressure to one of the speed ratio clutches, a directional selector valve for communicating fluid at the second pressure to one of the directional clutches, a first modulating valve in communication with the source and the speed ratio selector valve means for modulating fluid at the first pressure, a differential valve in communication with the fluid source, the first modulating valve and the directional selector valve, the differential valve including means to differentially establish the second pressure for communication to the directional selector valve, and a second modulating valve including manually adjustable modulating means for communicating fluid at the second pressure from the differential valve to the directional selector valve at a regulated rate, the second modulating valve further including relief means in operative communication with the first pressure modulating valve to selectively reduce the first fluid pressure during operation of the manually adjustable modulating means.
Claim 9
Dependent Claim
27 words
The hydraulic control circuit of claim 5 wherein the manually adjustable modulating means comprises a modulating spool responsively coupled with a manually adjustable element by resilient means.
Claim 10
Dependent Claim
43 words
The hydraulic control circuit of claim 6 wherein the relief means comprises a passage in the second modulating valve which is in communication with the first fluid pressure and which is opened to a fluid drain by movement of the manual control element.
Claim 11
Dependent Claim
254 words
A hydraulic transmission control circuit for selectively actuating one of a plurality of drive train clutches with hydraulic fluid at a first pressure and selectively actuating one of a plurality of master drive train clutches at a second pressure which is differentially related to the first pressure, comprising, a fluid source, first modulating means in communication with the fluid source to modulate fluid at the first pressure, differential means in communication with the modulating means for establishing the second fluid pressure, and a manual modulating valve including manual modulating means for communicating the second fluid pressure from the diffeRential means to one of the master drive train clutches and modulating the second fluid pressure communicated to the one master drive train clutch in two discreet operating modes in order to provide accurate regulating over master clutch engagement under different operating conditions, said two discreet operating modes being characterized by the selective modulating means in the manual modulating valve being operable to vary the second pressure at two different rates of modulation in order to selectively regulate the degree of engagement in the master drive train clutches, the manual modulating means of the manual modulating valve comprising a modulating valve spool, a manually adjustable element and first and second resilient means arranged for operative interaction between the modulating valve spool and manually adjustable element, the first and second resilient means having different spring characteristics in order to vary the second pressure at two distinctly different rates of modulation under control of the manually adjustable element.
Claim 12
Dependent Claim
254 words
A hydraulic transmission control circuit for selectively actuating one of a plurality of drive train clutches with hydraulic fluid at a first pressure and selectively actuating one of a plurality of master drive train clutches at a second pressure which is differentially related to the first pressure, comprising, a fluid source, first modulating means in communication with the fluid source to modulate fluid at the first pressure, differential means in communication with the modulating means for establishing the second fluid pressure, and a manual modulating valve including manual modulating means for communicating the second fluid pressure from the diffeRential means to one of the master drive train clutches and modulating the second fluid pressure communicated to the one master drive train clutch in two discreet operating modes in order to provide accurate regulating over master clutch engagement under different operating conditions, said two discreet operating modes being characterized by the selective modulating means in the manual modulating valve being operable to vary the second pressure at two different rates of modulation in order to selectively regulate the degree of engagement in the master drive train clutches, the manual modulating means of the manual modulating valve comprising a modulating valve spool, a manually adjustable element and first and second resilient means arranged for operative interaction between the modulating valve spool and manually adjustable element, the first and second resilient means having different spring characteristics in order to vary the second pressure at two distinctly different rates of modulation under control of the manually adjustable element.
Claim 13
Dependent Claim
47 words
The hydraulic transmission control circuit of claim 8 wherein the manual modulating valve further comprises means in operative communication with the first modulating means for reducing the first fluid pressure to a selected level during regulating operation of the manual modulating means within the manual modulating valve.
Claim 14
Dependent Claim
224 words
A hydraulic transmission control circuit for selectively actuating one of a plurality of drive train clutches with hydraulic fluid at a first pressure and selectively actuating one of a plurality of master drive train clutches at a second pressure which is differentially related to the first pressure, comprising a fluid source, first modulating means in communication with the fluid source to modulate fluid at the first pressure, differential means in communication with the modulating means for establishing the second fluid pressure, and a manual modulating valve including manual modulating means for communicating the second fluid pressure from the differential means to one of the master drive train clutches and modulating the second fluid pressure communicated to the one master drive train clutch in two discreet operating modes in order to provide accurate regulation over master clutch engagement under different operating conditions, said two discreet operating modes being characterized by the selective modulating means in the manual modulating valve being operable to vary the second pressure at two different rates of modulation in order to selectively regulate the degree of engagement in the master drive train clutches, the manual modulating valve further including means in operative communication with the first modulating means to reduce the first fluid pressure to a selected level during regulating operation of the manual modulating means within the manual modulating valve.
Claim 15
Dependent Claim
224 words
A hydraulic transmission control circuit for selectively actuating one of a plurality of drive train clutches with hydraulic fluid at a first pressure and selectively actuating one of a plurality of master drive train clutches at a second pressure which is differentially related to the first pressure, comprising a fluid source, first modulating means in communication with the fluid source to modulate fluid at the first pressure, differential means in communication with the modulating means for establishing the second fluid pressure, and a manual modulating valve including manual modulating means for communicating the second fluid pressure from the differential means to one of the master drive train clutches and modulating the second fluid pressure communicated to the one master drive train clutch in two discreet operating modes in order to provide accurate regulation over master clutch engagement under different operating conditions, said two discreet operating modes being characterized by the selective modulating means in the manual modulating valve being operable to vary the second pressure at two different rates of modulation in order to selectively regulate the degree of engagement in the master drive train clutches, the manual modulating valve further including means in operative communication with the first modulating means to reduce the first fluid pressure to a selected level during regulating operation of the manual modulating means within the manual modulating valve.
Claim 16
Dependent Claim
157 words
A hydraulic transmission control circuit for selectively actuating one of a plurality of drive train clutches with hydraulic fluid at a first pressure and selectively actuating one of a plurality of master drive train clutches at a second differentially lower pressure in relation to the first pressure, comprising, a fluid source, first modulating means in communication with the fluid source to modulate fluid at the first pressure, differential means in communication with the first modulating means for establishing the second differentially lower fluid pressure, and a manual modulating valve including manual modulating means which are selectively operable for regulating communication of the second differentially lower fluid pressure from the differential means to one of the master drive train clutches, the manual modulating valve further including means in operative communication with the first modulating means to reduce the first fluid pressure to a selected level during regulating operation of the manual modulating means within the manual modulating valve.
Claim 17
Dependent Claim
157 words
A hydraulic transmission control circuit for selectively actuating one of a plurality of drive train clutches with hydraulic fluid at a first pressure and selectively actuating one of a plurality of master drive train clutches at a second differentially lower pressure in relation to the first pressure, comprising, a fluid source, first modulating means in communication with the fluid source to modulate fluid at the first pressure, differential means in communication with the first modulating means for establishing the second differentially lower fluid pressure, and a manual modulating valve including manual modulating means which are selectively operable for regulating communication of the second differentially lower fluid pressure from the differential means to one of the master drive train clutches, the manual modulating valve further including means in operative communication with the first modulating means to reduce the first fluid pressure to a selected level during regulating operation of the manual modulating means within the manual modulating valve.
Claim 18
Dependent Claim
231 words
A hydraulic transmission control circuit for selectively actuating one of a plurality of drive train clutches with hydraulic fluid at a first pressure and for selectively actuating one of a plurality of master drive train clutches at a second pressure differentially related to a first pressure, comprising, a source of fluid under pressure, a first modulating valve including a modulating spool for establishing the first fluid pressure, the first modulating valve also including a load piston resiliently coupled with the modulating spool and arranged within a load piston chamber, the load piston chamber being in communication with fluid at the first pressure, differential means in communication with the modulating valve for establishing the second fluid pressure, and a second modulating valve including a second modulating spool for regulating communication of the second fluid pressure from the differential means to one of the master drive train clutches, the second modulating valve further including manually operable means operatively coupled with the second modulating spool, the second modulating valve also including relief means in communication with the load piston chamber of the first modulating valve, the relief means being responsive to the manually operable means in the second modulating valve for selectively relieving fluid pressure from the load piston chamber in the first modulating valve in order to reduce the first fluid pressure during operation of the modulating spool in the second modulating valve.
Claim 19
Dependent Claim
231 words
A hydraulic transmission control circuit for selectively actuating one of a plurality of drive train clutches with hydraulic fluid at a first pressure and for selectively actuating one of a plurality of master drive train clutches at a second pressure differentially related to a first pressure, comprising, a source of fluid under pressure, a first modulating valve including a modulating spool for establishing the first fluid pressure, the first modulating valve also including a load piston resiliently coupled with the modulating spool and arranged within a load piston chamber, the load piston chamber being in communication with fluid at the first pressure, differential means in communication with the modulating valve for establishing the second fluid pressure, and a second modulating valve including a second modulating spool for regulating communication of the second fluid pressure from the differential means to one of the master drive train clutches, the second modulating valve further including manually operable means operatively coupled with the second modulating spool, the second modulating valve also including relief means in communication with the load piston chamber of the first modulating valve, the relief means being responsive to the manually operable means in the second modulating valve for selectively relieving fluid pressure from the load piston chamber in the first modulating valve in order to reduce the first fluid pressure during operation of the modulating spool in the second modulating valve.
Claim 20
Dependent Claim
28 words
The hydraulic transmission control circuit of claim 12 further comprising first and second resilient means arranged for interaction between the second modulating spool and the manually operable means.
Claim 21
Dependent Claim
240 words
A hydraulic transmission control circuit for selectively actuating a master clutch with hydraulic fluid pressure and for selectively actuating one or more additional clutches with hydraulic fluid pressure, comprising a fluid source, a first selector valve means for communicating fluid to the master clutch, a second selector valve for communicating fluid to one of the additional clutches, first pressure modulating valve means in communciation with the source, the first selector valve means and the second selector valve means, and a manually controlled modulating valve arranged for communication with the first pressure modulating valve means and the first selector valve, the manually controlled modulating valve including means for selectively modulating fluid pressure communicated to the first selector valve in two discreet operating modes in order to provide more precise regulation over master clutch engagement under different operating conditions, the selective modulating means being operable to adjust the fluid pressure communicated to the first selector valve at two different rates of modulation for providing the two discreet operating modes, the selective modulating means in the manual modulating valve comprising a modulating valve spool, a manually adjustable element and first and second resilient means arranged for operative interaction between the modulating valve spool and manually adjustable element, the first and second resilient means having different spring characteristics in order to vary the pressure communicated to the first selector valve at two distinctly different rates of modulation under control of the manually adjustable element.
Claim 22
Dependent Claim
240 words
A hydraulic transmission control circuit for selectively actuating a master clutch with hydraulic fluid pressure and for selectively actuating one or more additional clutches with hydraulic fluid pressure, comprising a fluid source, a first selector valve means for communicating fluid to the master clutch, a second selector valve for communicating fluid to one of the additional clutches, first pressure modulating valve means in communciation with the source, the first selector valve means and the second selector valve means, and a manually controlled modulating valve arranged for communication with the first pressure modulating valve means and the first selector valve, the manually controlled modulating valve including means for selectively modulating fluid pressure communicated to the first selector valve in two discreet operating modes in order to provide more precise regulation over master clutch engagement under different operating conditions, the selective modulating means being operable to adjust the fluid pressure communicated to the first selector valve at two different rates of modulation for providing the two discreet operating modes, the selective modulating means in the manual modulating valve comprising a modulating valve spool, a manually adjustable element and first and second resilient means arranged for operative interaction between the modulating valve spool and manually adjustable element, the first and second resilient means having different spring characteristics in order to vary the pressure communicated to the first selector valve at two distinctly different rates of modulation under control of the manually adjustable element.
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) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |