Tractor hydraulic brake circuit with abs capability
AssigneeDeere & Company
InventorsTROY E. SCHICK, Boris Volfson
Life of this patent
Estimating the term…
Abstract
A vehicle brake system includes a pump, a sump, brake units and left and right manually operated brake valves. The brake system also includes, for each brake unit, a solenoid operated on-off valve having a first port connected to a pilot of one of the brake valves, a second port, a third port connected to one of the brake units, a solenoid and a spring which opposes the solenoid. The brake system also includes, for each brake unit, a solenoid operated proportional valve. Each proportional valve controls communication between the pump, the sump and the second port of a corresponding one of the on-off valves.
Claims12
A vehicle brake system comprising:
- a hydraulic pump;
- a sump;
- a left brake unit;
- a right brake unit;
- a left manually operated brake valve having a first pressure responsive pilot acting in opposition to a left manual actuator;
- a right manually operated brake valve having a second pressure responsive pilot acting in opposition to a right manual actuator;
- a solenoid operated left on-off valve having a first port connected to the first pilot, a second port, a third port connected to left brake unit, a solenoid and a spring which opposes the solenoid;
- a solenoid operated right on-off valve having a first port connected to the second pilot, a second port, a third port connected to right brake unit, a solenoid and a spring which opposes the solenoid;
- a pair of solenoid operated proportional valves, each proportional valve controlling communication between the pump, the sump and the second port of a corresponding one of the on-off valves.
A vehicle brake system comprising:
- a hydraulic pump;
- a sump;
- a left rear brake unit;
- a right rear brake unit;
- a left front brake unit;
- a right front brake unit;
- a left manually operated brake valve having a first pressure responsive pilot acting in opposition to a left manual actuator;
- a right manually operated brake valve having a second pressure responsive pilot acting in opposition to a right manual actuator;
- a solenoid operated left rear on-off valve having a first port connected to the first pilot, a second port, a third port connected to left rear brake unit, a solenoid and a spring which opposes the solenoid;
- a solenoid operated right rear on-off valve having a first port connected to the second pilot, a second port, a third port connected to right rear brake unit, a solenoid and a spring which opposes the solenoid;
- a solenoid operated left front on-off valve having a first port connected to the sump, a second port, a third port connected to left front brake unit, a solenoid and a spring which opposes the solenoid;
- a solenoid operated right front on-off valve having a first port connected to the sump, a second port, a third port connected to right front brake unit, a solenoid and a spring which opposes the solenoid;
- and
- a plurality of solenoid operated proportional valves, each proportional valve controlling communication between the pump, the sump and the second port of a corresponding one of the on-off valves.
Dependencies are inferred from the claim text.