摘要:
A power steering and brake system for a vehicle, especially an off-highway articulated vehicle, having a brake actuating accumulator by diverting a small amount of fluid flow from a steering circuit. A self acting emergency brake is activated upon loss of accumulator pressure below a level satisfactory for operating the service brakes. The emergency brake may also be selectively operated as a parking brake when the vehicle is halted by dumping pressure from the accumulator.
摘要:
A hydraulic booster brake mechanism for use with an open center power steering system of a motor vehicle in which a booster brake mechanism employs a mechanism permitting operation of the booster brake mechanism utilizing the pressures already made available due to operation of the power steering system. In the event the available pressure from the power steering system is not sufficient to accomplish the degree of braking desired, the control mechanism is actuated to increase and maintain the pressure produced by the power steering system at predetermined minimum pressure levels slightly above the pressure level necessary to accommodate the requirements of the booster brake mechanism.
摘要:
The return of actuating fluid from a vehicle brake is diverted to a sump-connected bypass line and is prevented from returning through the brake control valve by a shuttle valve which is interposed in the brake line between the brake and the control valve. The shuttle valve shifts in response to the fluid pressure in the brake line to connect fluid pressure to the brakes and block the bypass line when the control valve is positioned for actuating the brake and to block the brake line and open the bypass line when the control valve is positioned for deactivating the brake.
摘要:
A control system for a differential having first and second output shafts and hydraulic brakes for the respective shafts. The control system includes a friction device for locking and unlocking the differential and a valve which progressively pressurizes the friction device in timed relation to initial supply of pressured fluid from a source to the valve. The valve cooperates with the brakes and releases the friction device whenever either of the brakes is actuated.
摘要:
Each track of a crawler vehicle is provided with a hydraulically operated drive clutch and brake. A control valve and a pilot operated sequencing relief valve are provided to operate each clutch and brake set. These valves operate to fully disengage the clutches before the brakes are applied and to fully release the brakes before the clutches are reengaged to minimize wear on the clutches and brakes. The relief valve is movable between clutch and brake operating positions and is responsive to completion of these operations to control the supply of hydraulic fluid to the control valve.
摘要:
A hydraulic valve with an inlet port for high-pressure fluid, an outlet port leading to a load such as a hydraulically operated clutch or brake, and a discharge port communicating with a lowpressure region or sump has a slider which, in response to the pressure of incoming fluid at the inlet port, initially establishes a connection between the inlet and outlet ports and, in response to fluid pressure building up in that connection, shifts into a regulating position in which the inlet port is partly cut off and/or the discharge port partly communicates with the outlet port to establish a balance between the inlet pressure and a counteracting pressure from a spring and/or a separate generator of variable fluid pressure. A branch conduit extends from the outlet port to a cylinder of a piston controlling the counteracting pressure, this conduit including a throttle resulting in a gradual or sudden increase of that pressure and, with it, of the load pressure as the piston moves progressively or instantaneously into an alternate position.
摘要:
A hydraulic system for a vehicle having a conventional opencenter steering system powered by an engine-driven rotary pump with a valve that enables a small portion of the fluid delivered by the pump to be stored in an accumulator between predetermined pressure limits. The invention visualizes the use of the fluid in the accumulator for such purposes as actuating a power brake booster and/or other devices within the vehicle.