US3854559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for a hydraulically-operable brake and transmission
Assignee: Deere and Co
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Filing: 1973-10-01
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Granted: 1974-12-17
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Expires: 1993-10-01
Abstract
Abstract A motor vehicle includes a hydraulically-operated transmission means and a hydraulically operated brake means which are controlled through means of an interlocked control system. The brake means is normally engaged in the absence of fluid pressure and a pump serves both as the charging pump for the fluid pressure to operate the transmission means and as the fluid supply pump for actuating the brake means. The control system includes a valve arrangement for disengaging the transmission means and applying the brake means at any time when transmission charge pressure drops to a predetermined level. The valve arrangement also provides for disengaging the transmission at any time that the service brake is applied. The valve arrangement further provides for releasing the brake means, in response to a manual actuation of a master cylinder, for permitting the vehicle to be towed or otherwise moved when the engine is inoperative.
Inventors
- 👤 J Talak
- 👤 J Hobson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:39
CPC Classifications
B; B60; B60T; B60T13/00; B60T13/10; B60T13/12; B60T13/22; B60T11/00; B60T11/10; B60T11/103; B60W; B60W10/00; B60W10/10; B60W10/18; F; F16; F16H; F16H59/00; F16H59/50; F16H59/54; F16H61/00; F16H61/38; F16H61/40; F16H61/4078; F16H61/4139
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
294 words
A hydraulic brake and transmission control system comprising: a vehicle brake means; biasing means connected to said brake means for normally holding said brake means in an engaged condition; one-way hydraulic motor means connected to said brake means and pressure actuatable for moving said brake means to a disengaged condition against the force of said biasing means; a hydraulic fluid conduit means connected to said motor means and including first and second branch means; a vehicle engine-driven pump having an outlet connected to the first branch means; a sump connected to the second branch means; a normally closed brake control valve means located solely in said second branch means and shiftable to simultaneously connect the motor means and said pump to sump to thereby permit the brake means to become engaged by the action of said biasing means; actuator means for selectively shifting said brake control valve means to an open position from its closed position; a hydraulically operable transmission means; a return conduit means including a normally open pilot-operable dump valve means connecting said transmission means to said sump; a pressure fluid supply conduit means connecting said outlet of the pump to said transmission means exclusive of said dump valve means; said dump valve means being connected to said outlet of the pump and operative in response to the pressure fluid delivered by said pump being above a pre-determined minimum, indicative of normal vehicle engine operation, to block the flow of fluid between said transmission means and said sump, whereby said transmission means will be deactivated both when said brake control valve means is shifted to said open position and when the pump is driven too slowly by the vehicle engine to supply said pre-determined minimum pressure, as when the engine is stalling.
Claim 2
Dependent Claim
294 words
A hydraulic brake and transmission control system comprising: a vehicle brake means; biasing means connected to said brake means for normally holding said brake means in an engaged condition; one-way hydraulic motor means connected to said brake means and pressure actuatable for moving said brake means to a disengaged condition against the force of said biasing means; a hydraulic fluid conduit means connected to said motor means and including first and second branch means; a vehicle engine-driven pump having an outlet connected to the first branch means; a sump connected to the second branch means; a normally closed brake control valve means located solely in said second branch means and shiftable to simultaneously connect the motor means and said pump to sump to thereby permit the brake means to become engaged by the action of said biasing means; actuator means for selectively shifting said brake control valve means to an open position from its closed position; a hydraulically operable transmission means; a return conduit means including a normally open pilot-operable dump valve means connecting said transmission means to said sump; a pressure fluid supply conduit means connecting said outlet of the pump to said transmission means exclusive of said dump valve means; said dump valve means being connected to said outlet of the pump and operative in response to the pressure fluid delivered by said pump being above a pre-determined minimum, indicative of normal vehicle engine operation, to block the flow of fluid between said transmission means and said sump, whereby said transmission means will be deactivated both when said brake control valve means is shifted to said open position and when the pump is driven too slowly by the vehicle engine to supply said pre-determined minimum pressure, as when the engine is stalling.
Claim 3
Dependent Claim
294 words
A hydraulic brake and transmission control system comprising: a vehicle brake means; biasing means connected to said brake means for normally holding said brake means in an engaged condition; one-way hydraulic motor means connected to said brake means and pressure actuatable for moving said brake means to a disengaged condition against the force of said biasing means; a hydraulic fluid conduit means connected to said motor means and including first and second branch means; a vehicle engine-driven pump having an outlet connected to the first branch means; a sump connected to the second branch means; a normally closed brake control valve means located solely in said second branch means and shiftable to simultaneously connect the motor means and said pump to sump to thereby permit the brake means to become engaged by the action of said biasing means; actuator means for selectively shifting said brake control valve means to an open position from its closed position; a hydraulically operable transmission means; a return conduit means including a normally open pilot-operable dump valve means connecting said transmission means to said sump; a pressure fluid supply conduit means connecting said outlet of the pump to said transmission means exclusive of said dump valve means; said dump valve means being connected to said outlet of the pump and operative in response to the pressure fluid delivered by said pump being above a predetermined minimum, indicative of normal vehicle engine operation, to block the flow of fluid between said transmission means and said sump, whereby said transmission means will be deactivated both when said brake control valve means is shifted to said open position and when the pump is driven too slowly by the vehicle engine to supply said pre-determined minimum pressure, as when the engine is stalling.
Claim 4
Dependent Claim
294 words
A hydraulic brake and transmission control system comprising: a vehicle brake means; biasing means connected to said brake means for normally holding said brake means in an engaged condition; one-way hydraulic motor means connected to said brake means and pressure actuatable for moving said brake means to a disengaged condition against the force of said biasing means; a hydraulic fluid conduit means connected to said motor means and including first and second branch means; a vehicle engine-driven pump having an outlet connected to the first branch means; a sump connected to the second branch means; a normally closed brake control valve means located solely in said second branch means and shiftable to simultaneously connect the motor means and said pump to sump to thereby permit the brake means to become engaged by the action of said biasing means; actuator means for selectively shifting said brake control valve means to an open position from its closed position; a hydraulically operable transmission means; a return conduit means including a normally open pilot-operable dump valve means connecting said transmission means to said sump; a pressure fluid supply conduit means connecting said outlet of the pump to said transmission means exclusive of said dump valve means; said dump valve means being connected to said outlet of the pump and operative in response to the pressure fluid delivered by said pump being above a predetermined minimum, indicative of normal vehicle engine operation, to block the flow of fluid between said transmission means and said sump, whereby said transmission means will be deactivated both when said brake control valve means is shifted to said open position and when the pump is driven too slowly by the vehicle engine to supply said pre-determined minimum pressure, as when the engine is stalling.
Claim 5
Dependent Claim
127 words
The hydraulic brake and transmission control system defined in claim 1 and further including a manually operable pump means having an inlet connected to said sump and having an outlet connected to said hydraulic fluid conduit means between said brake means and said brake control valve means; and a check valve means being located in said hydraulic fluid conduit means between the outlet of said pump means and said pump and hydraulic motor means and operable in response to fluid pressure delivered by said pump means to move from a normally closed position, wherein the flow of fluid from the conduit means to the pump means is blocked, to an open position, wherein the flow of fluid from said pump means to said motor means is permitted.
Claim 6
Dependent Claim
98 words
The hydraulic brake and transmission assembly defined in claim 1 wherein said dump valve means is a spool valve having a body in which is located a valve bore; said bore having separate connections with said transmission means and said sump and containing a reciprocably mounted valve spool element; biasing means uring said spool element towards a normal position connecting said transmission means to said sump; and said bore being connected to said conduit means such that fluid pressure in said conduit means acts on the spool element in a direction opposite to that of the biasing means.
Claim 7
Dependent Claim
86 words
The hydraulic brake and transmission assembly defined in claim 2 wherein said pump means is a master cylinder assembly including a piston reciprocably mounted in a cylinder bore and connected to a lever for selectively shifting the same; said sump being connected to said cylinder bore so as to admit fluid on opposite sides of the piston when the latter is in a normally released position; and a biasing means acting on said piston in a direction tending to maintain it in said normally released position.
Claim 8
Dependent Claim
55 words
The hydraulic brake and transmission control system defined in claim 2 wherein said check valve means includes a valve body containing fluid passages forming an intersection of said conduit means at the branching point of said first and second branch means and the connection of the outlet of said pump means with said conduit means.
Claim 9
Dependent Claim
38 words
The hydraulic brake and transmission control system defined in claim 1 wherein said brake control valve means includes a normally seated poppet valve element; and manually operable cam means being mounted for selectively unseating said poppet valve element.
Claim 10
Dependent Claim
107 words
The hydraulic brake and transmission control system defined in claim 7 and further including a manually operable pump means having an inlet connected to said sump and having an outlet connected to said actuator means; and a check valve means being located between the outlet of said pump means and said actuator means and operable in response to fluid pressure delivered by said pump means to move from a normally closed position, wherein the flow of fluid from the pump means outlet to the actuator means is blocked, to an open position, wherein the flow of fluid from said pump means outlet to said actuator is permitted.
Claim 11
Dependent Claim
98 words
The hydraulic brake and transmission assembly defined in claim 7 wherein said dump valve means is a spool valve having a body in which is located a valve bore; said bore having separate connections with said transmission means and said sump and containing a reciprocably mounted valve spool element; biasing means urging said spool element towards a normal position connecting said transmission means to said sump; and said bore being connected to said pump outlet such that fluid pressure delivered by said pump acts on the spool element in a direction opposite to that of the biasing means.
Claim 12
Dependent Claim
86 words
The hydraulic brake and transmission assembly defined in claim 8 wherein said pump means is a master cylinder assembly including a piston reciprocably mounted in a cylinder bore and connected to a lever for selectively shifting the same; said sump being connected to said cylinder bore so as to admit fluid on opposite sidEs of the piston when the latter is in a normally released position; and a biasing means acting on said piston in a direction tending to maintain it in said normally released position.
Claim 13
Dependent Claim
42 words
The hydraulic brake and transmission control system defined in claim 8 wherein said check valve means includes a valve body containing fluid passages forming an intersection of conduit means connecting the pump outlet to the actuator means and brake control valve means.
Claim 14
Dependent Claim
38 words
The hydraulic brake and transmission control system defined in claim 7 wherein said brake control valve means includes a normally seated poppet valve element; and manually operable cam means being mounted for selectively unseating said poppet valve element.
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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) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |