Abstract: In a continuously variable hydrostatic transmission including a hydraulic pump unit driven by an input shaft, a grounded hydraulic motor unit, and an intermediate, wedge-shaped swashplate for developing torque on an output shaft in response to pumped exchanges of hydraulic fluid between the pump and motor units through swashplate ports, a ratio controller is provided to vary transmission ratio by changing the swashplate angular orientation and to engage a lock-up clutch directly mechanically coupling the input shaft to the output shaft when a 1:1 transmission ratio is set.

Abstract: A braking apparatus for a hydraulic motor (20) having a rotary component (21) includes a rotary side friction plate (22) coupled to the rotary component of the hydraulic motor, a fixed side friction plate (23) coupled to a fixed component of the hydraulic motor, and a braking cylinder assembly (24) having a piston (25), a spring (26) and a piston pressure receiving chamber (27). The piston is energizable by the spring to move in a braking direction for bringing the fixed side and the rotary side friction plates into a pressure contact, whereas the piston pressure receiving chamber can be be supplied with pressure fluid to displace the piston in a braking release direction, thereby separating the fixed side friction plate and the rotary side friction plate from each other. An operating valve (41, 42) supplies pressure fluid into the hydraulic motor, and a hydraulic pilot valve (52, 53) provides pilot pressure fluid for use to switch the operating valve.

Abstract: What is disclosed is an inching and braking system for a hydraulically powered apparatus with a brake system and a drive system, wherein the drive system and the brake system can be controlled in order to generate a braking effect by actuating the inching and braking system. In the solution according to the invention, an inching valve arrangement and a brake valve arrangement can be coupled mechanically to one another so that the apparatus can be controlled more sensitively during transition from inching to braking.

Abstract: This invention relates to a hydraulic fluid circuit comprising a reversible hydraulic motor, a braking device, two principal conduits respectively connected to the two principal supply and exhaust ports of the motor, a principal selector adapted to occupy a position of rest and two active positions in order to select the circulation of the fluid between the principal ports of the motor and the principal conduits to which they are connected. The circuit also comprises an intermediate system of selection capable of occupying a first configuration in which the principal selector is maintained in its position of rest and a second configuration in which the principal selector is allowed to leave its position of rest. The control means of the intermediate system of selection are connected to the braking device so that this intermediate system can pass from its first to its second configuration only when the brake is de-activated.

Abstract: The method for preventing the interruption of tension during connection and disconnection of a first hydraulic motor to and from the power train of vehicles, in particular loaders, consists in that during the disconnection of the first hydraulic motor the high-pressure line is connected with the low-pressure line thereof, a flow distributor is readjusted so that the amount of oil fed to the first hydraulic motor is not increased, the pressure on a second hydraulic motor not to be disconnected being raised to a new value which remains constant during the disconnection, of the first hydraulic motor, a pump is readjusted to the new required (reduced) flow rate; and after adjustment of the pump to the new flow rate, the connection of the high-pressure line with the low-pressure line of the first hydraulic motor is eliminated; and during the connection of the hydraulic motor said method steps are carried out in reverse sequence.

Abstract: The present invention relates to a method of operating a winch, in which a rope which is wound onto a driven reel is supplied to at least one capstan head and wound around said capstan head, with a capstan drive rotating the capstan head and producing a rope advance due to the rope friction existing between rope and capstan head. Moreover, the present invention relates to a corresponding device. As an improvement of the method and the device, the invention suggests a reel drive which is adjusted separately next to the capstan drive.

Abstract: A braking apparatus includes a brake cylinder having a first opening and a second opening defined therein. The braking apparatus also includes a movable member located within the brake cylinder which has a channel defined therein. The braking apparatus further includes a brake chamber in fluid communication with the brake cylinder. The brake chamber has a brake member located therein. The movable member is moved to a position which allows fluid communication between the first and second opening through the channel thus creating a subsequent pressure drop in the system. The pressure drop causes a hydrostatic transmission in fluid communication with the brake apparatus to be neutralized by a responsive displacement of a pump and motor which reduces the travel speed of a vehicle. Additionally, the movement of the movable member causes a brake member to be forced against a moving object.

Abstract: A two wheel drive motorcycle is provided with an unsteerable rear wheel, a steerable front wheel, a drive unit having a driving motor for driving the rear wheel and a transmission device coupled to the drive unit for driving the front wheel. The transmission device has a hydrostatic drive having a hydraulic pump driven by the driving motor and whose hydraulic motor is mounted on an arm of the front fork. The hydraulic pump has constant output and the hydraulic motor has a constant input matched to the pump output. Hydraulic fluid is delivered from the hydraulic pump to the hydraulic motor by a pressure line. The pressure in the pressure line is controlled by a pressure control valve which can be adjusted to maintain a pressure in the range of approximately 20 to 200 bars.

Abstract: A hydrostatic continuously variable transmission is provided in which a hydraulic pump and a hydraulic motor are communicated to each other through a low pressure oil passage and a high pressure oil passage and a clutch valve capable of releasing an oil pressure of the high pressure oil passage is connected to the high pressure oil passage. The clutch valve can be automatically operated by making use of an oil pressure of the low pressure oil passage. A clutch valve is applied with an oil pressure of a low pressure oil passage for biasing the clutch valve in a valve opening direction, and an oil pressure governor is connected to a supply oil passage for supplying an oil pressure from an oil supply pump to the low pressure oil passage through a check valve for increasing an oil pressure of the oil passage in accordance with an increase in an input rotational speed of a hydraulic pump.

Abstract: A hydraulic deceleration control for a hydraulic motor includes a pilot operated control valve for controlling fluid flow through a pair of motor lines connected to the opposite sides of the hydraulic motor. A valve device is disposed to communicate a source of pressurized fluid to a fluid energy storage device when the control valve is in its open position and to release the pressurized fluid contained in the storage device when the control valve is moved from the open position to its closed position. A throttle orifice releases the fluid from the storage device at a controlled flow rate. A pilot operated diverter valve is disposed in series with an orifice disposed between the motor lines to control fluid flow through the orifice and has a spring disposed at a first end resiliently biasing the diverter valve to its closed position.

Abstract: A press includes a drive system which includes a brake and a clutch operated by fluid pressure. The brake and clutch control the movement of a crankshaft in relation to a flywheel. A unique control system supplies the pressurized fluid for operation of the brake and clutch. The unique control system includes a pressure relief valve for defining a maximum fluid pressure and a plurality of valve modules which each define a specific fluid pressure. Each valve module is selectively movable between a relief condition and a blocked condition. Thus, by selectively operating the valve modules, it is possible to select the fluid pressure being supplied to the brake and clutch.

Abstract: A hydraulic pressure supply system for a variable torque transfer of a four-wheel drive vehicle in which a driving-torque distribution ratio between front and rear road wheels is varied by adjusting a clutch pressure applied to a variable torque clutch assembled in said transfer, comprises an oil pressure source supplying a pressurized working fluid into a hydraulic line, at least one pressure regulating valve fluidly connected to the line for decreasingly regulating the pressurized working fluid at a predetermined clutch pressure, and a directional control valve fluidly connected to the pressure regulating valve for directing the clutch pressure to a transfer clutch. An electromagnetic solenoid valve is provided for controlling the pressure regulating valve and the directional control valve for selectively supplying one of a stand-by pressure and a clutch engaging pressure to the transfer clutch.

Abstract: In a drive unit which includes an electric motor and a cooling fan as well as a hydraulic power steering pump to be driven by the electric motor, the cooling fan is operatively connected to the motor by a clutch and a control circuit is provided for operating the clutch so as to disengage the cooling fan whenever the power steering unit needs hydraulic fluid for steering assistance, whereby both, the cooling fan and the hydraulic pump, are never operated at the same time so that the motor may be relatively small, light and inexpensive.

Abstract: In a wheeled vehicle propelled by a hydrostatic transmission which has a variable displacement pump fluidly connected to a motor in a closed circuit for propulsion and a hydraulically-released brake for stopping the vehicle, a return to neutral and brake release circuit including: a system reservoir for holding fluid; a charge pump for drawing fluid from the reservoir and providing pressurized flow of same; a hydraulically-released brake operatively attached to the wheels of vehicle and the charge pump; a displacement control for providing differential pressure command signals to a servo piston for varying hydrostatic transmission displacement; a solenoid valve for interrupting the flow of fluid to the brake and displacement control, thus braking the vehicle and returning the variable pump to neutral; and a set of drain passages fluidly connecting the solenoid, displacement control and brake (through the solenoid) to the system reservoir so that the components may be immediately drained to allow the engagemen

Abstract: The steering of a motor vehicle is assisted by a power steering means including a hydraulic distributor which is supplied with pressurized fluid by a pump from a reservoir. The vehicle also has a clutch having hydraulic servo assistance supplied by a servo unit. The distributor of the power steering system and the clutch servo unit are both supplied with hydraulic fluid from the same pump and reservoir, through a distribution unit which is so arranged that the power steering system has first call at all times on the available pressurized fluid. The distributor unit includes a flow distributing valve, fed from the pump and dividing the flow between a main circuit which leads to the steering distributor, and a secondary circuit which leads to the servo unit. A pressure regulating valve is connected to both the main circuit and the secondary circuit so as to regulate the pressure in each of these circuits according to the demand of the power steering system.

Abstract: In an open state of a valve, when a valve outside sleeve is rotated in the rear portion of a housing, a valve inner sleeve is moved forward to close a fluid channel, thus stopping supply of compressed driving air. Simultaneously, a front end of the valve outside sleeve is moved forward while it abuts against the rear surface of a retainer. Therefore, brake rods biased by compression coil springs are also moved forward, and front surfaces of the brake rods are abutted against a brake disk to effect braking, thereby immediately stopping rotation of a rotor. The urging force applied on the brake disk is the compression force of the compression coil springs.

Abstract: A hydrostatic transmission system axle driving apparatus for changing the speed of a vehicle which includes a hydraulic pump, hydraulic motor and braking unit. Neutral valves at an open position are automatically returned to a closed position with the operation of a brake controller. This allows the vehicle to be started at slow speed, but not abruptly.

Abstract: A door operator having a fluid drive motor and a manual override. The bidirectional hydraulic motor connects to a drive shaft through a power train including a shiftable --quill--type manual clutch mechanism which allows an alternate connection of the drive shaft to a manually-operated wheel. When the cable which shifts the clutch for manual drive is pulled, a switch disables the control for the hydraulic motor. When the motor is not provided with pressured fluid from the pump a hydraulic brake engages the motor.

Abstract: A hydraulically powered actuator (16) for moving a member (28 or 30) into and away from a position at which the member is under a preload is disclosed. A hydraulically powered motor (22) is utilized which is coupled to the member for moving the member to and from the position at which the member is preloaded. A source (40) of pressurized hydraulic fluid is coupled to the hydraulic motor for supplying power to the motor for moving the movable member. A brake (32) is provided which is coupled to the movable member for holding the movable member in the position at which the member is preloaded. A hydraulic fluid control is provided which is coupled to the motor, the brake and the source of pressurized fluid which activates the brake after the motor has moved the member to the position at which the member is preloaded and deactivates the motor while maintaining the member under preload.

Abstract: A vehicle includes at least a pair of drive wheels, each wheel being independently controlled by an integrated transmission, each transmission being powered by an input shaft operably driven by a common engine. Each transmission is of a type wherein a pump head with pistons is driven by the input shaft and conveys output fluid to a motor head which is driven thereby and rotates and output shaft. Pump head output is controlled by an operator variable swash plate. The transmission integrally includes a dampening mechanism for the swash plate, a positive neutral structure for the swash plate, an automatic parking brake with override mechanism to allow setting of the brake or release of the brake by the operator, a porting block communicating fluid flow between the pump heads and providing for overpressure relief, and a charge pump for communicating makeup fluid to the pump head and to circulate the fluid so as to cool same.

Abstract: The brake circuit apparatus for a hydraulic motor in a hydraulic circuit system having at least one main hydraulic pump, a hydraulic motor driven by a hydraulic fluid supplied from the main pump and having a rotary shaft, and a directional control valve actuated by an operation device for control of flow rate and flow direction of the hydraulic fluid supplied to the hydraulic motor from the main pump. The hydraulic motor is provided with a mechanical brake device having a brake release cylinder adapted to release the rotary shaft of the motor from the braking by the mechanical brake device by supply of a hydraulic fluid to the brake release cylinder. The apparatus further has an auxiliary hydraulic pump and a control circuit connected to the auxiliary pump, brake release cylinder and reservoir for control of fluid communication therebetween.

Abstract: An inching system for use in a vehicle for performing work which permits the vehicle to be moved at reduced speeds while maintaining sufficient engine speed, and therefore, sufficient hydraulic fluid flow and pressure for actuating the work-performing apparatus. The inching system includes a control valve for controlling the amount of hydraulic fluid which a forward-reverse valve is able to direct to the rear drive means, an orifice through which hydraulic fluid flows from a source of hydraulic fluid to the control valve to restrict the flow of fluid to a level below that of the flow to the work-performing apparatus, and a variable inching valve for metering hydraulic fluid from the control valve so that fluid pressure available to the forward-reverse valve, and in turn, to the rear drive means, is progressively reduced. A pedal is provided in the cab of the vehicle to selectively actuate the variable inching valve to effect inching control.

Abstract: A hydraulic power system having a variable displacement hydraulic pump, a hydraulic motor driven by the hydraulic pump for actuating a load, with the pump and motor being connected to constitute a closed hydraulic circuit. A hydraulic servo controls the displacement volume of the pump, and a motor stop arrangement prevents, in its operative position, the motor from rotating. The system includes a control valve responsive to a main line pressure in the closed hydraulic circuit for controlling a hydraulic fluid supply to the hydraulic servo to prevent the main line pressure from substantially exceeding a predetermined level, and a control is responsive to the operation of the hydraulic servo for releasing the motor stop arrangement from the operative position when the hydraulic servo is operating.

Abstract: A spring applied and hydraulically released motor shaft brake apparatus for a hydraulic motor which is compact in size. The brake apparatus includes a piston slidably mounted in a cylinder defining a brake chamber and a drain chamber. The piston is slidably and rotatably mounted on the motor shaft and a spring is disposed in the drain chamber for biasing the piston towards the brake chamber to thereby lock the motor shaft against rotation. The brake chamber is selectively connectible with a pressurized fluid source while the drain chamber is connected with a drain. The piston has formed therein a passage with a restrictor disposed therein for restricting flow of fluid in the passage.

Abstract: Hydrostatic transmissions are commonly employed in the drive train of earthmoving and industrial vehicles. It is difficult to stop some such vehicles at a precise location on a slope due to the presence of a delay valve included in the controls for delaying application of a friction brake until the vehicle has been stopped by the hydrostatic transmission. In the present control system, a manual control valve (74) is moved to a first operative position and a hand control lever (25) is manipulated in combination therewith to reduce the displacement of a variable displacement pump (12) to establish a minimum drive condition sufficient to hold the vehicle motionless. Thereafter the manual control valve (74) can be moved to a second operative position to apply a friction brake (18) while the transmission maintains the vehicle motionless.

Abstract: A hydrostatic transmission has an engine-driven, bidirectional, variable-displacement drive pump connected in circuit with a bidirectional, variable-displacement propelling motor. A charging pump is also connected to the circuit of the drive pump and the propelling motor. A brake assembly normally locks the output shaft of the propelling motor against rotation and releases same only while being supplied with a hydraulic brake release signal. The control system for the hydrostatic transmission comprises a speed control valve actuated manually to deliver fluid pressure signals to servo controls for adjusting the outputs from the drive pump and the propelling motor, and a brake control valve pilot-operated to deliver the brake release signal to the brake assembly. Also included are a charge sensor valve and a speed control sensor valve.

Abstract: A hydraulic power system having a variable displacement hydraulic pump, a hydraulic motor driven by the hydraulic pump for actuating a load, the pump and motor being connected to constitute a closed hydraulic circuit, hydraulic servo for controlling the displacement volume of the pump, and motor stopping device including a brake arrangement adapted to release the motor from a braked condition when a control pressure from a hydraulic fluid source is received.

Abstract: A fluid control cirucit for selectively varying the displacement of a variable displacement pump (P), such as the type employed in a hydrostatic transmission, comprises a primary control circuit connecting a pressurized fluid source (10) with the pump (P) and adapted to be actuated to selectively vary the displacement of the pump (P) between minimum and maximum values. A separate override control circuit is connected to the primary control circuit to override it to selectively vary the displacement of the pump (P).

Abstract: Crawler tractor adapted for stepless hydromechanical or electromechanical steering by driving. The tractor, in which opposite axles have interposed solid axle steering drive means, is steered by means of clutches disposed one between the drive means and each axle for primary mechanical drive, and a secondary variable ratio hydrostatic bidirectional drive interconnecting the axles.

Abstract: A hydraulic circuit for a hydraulically driven vehicle comprising an engine, a variable displacement pump driven by the engine, a hydraulic motor connected with the variable displacement pump and driven thereby, the hydraulic motor having an output shaft connected thereto, a first fixed displacement pump driven by the engine, an inching brake valve connected with the first fixed displacement pump, a control valve connected with the output side of the inching brake valve for controlling the forward and reverse movement of the vehicle and speed thereof, the output side of which is connected with the variable displacement pump, a parking brake coupled with the output shaft of the hydraulic motor, the parking brake being normally applied by a spring and hydraulically released, a pilot operated first brake control valve connected with the parking brake, a manually operated pump connected with the first brake control valve and the inching brake valve, a pilot operated second brake control valve connected with the f

Abstract: A nonlinear hydraulic pump control provides a primary control output as a mechanical actuator arm displacement either side of a neutral or "Off" position. A secondary control, also cam activated, operates in selectable offset sequence with the primary output, with the offset magnitude being selectively adjustable and effected either symmetrically about the primary control neutral position or differentially with respect thereto. The secondary control is useful in starting, stopping, or modulating accessory gear which cooperates with the pump operation, such as brake release control for a hydraulic winch to assure controlling hydraulic pressure buildup prior to brake release for both inhaul and outhaul operations where the winch cable is constantly subjected to tension loading.