Abstract: A rotor system comprising a driveshaft; at least one motor for providing rotational energy for the driveshaft; an overrunning clutch connected to the motor and disposed around the driveshaft, wherein the overrunning clutch is rotated by the at least one motor; and a pump assembly associated with the at least one motor, the pump assembly comprising a large bore through which the driveshaft passes such that the pump assembly is arranged concentric to the driveshaft, the pump assembly further comprising a gerotor pump comprising inner and outer gerotor pump gears, wherein an inner bore of the gerotor pump engages and is driven by the overrunning clutch; and a cover disposed over the gerotor pump for providing a sump for the gerotor pump.

Abstract: An electric drive axle of a vehicle includes an electric motor having an output shaft. An idler assembly is drivingly coupled to the electric motor and a differential. The idler assembly includes a first gear-clutch assembly to facilitate a first gear ratio and a second gear-clutch assembly to facilitate a second gear ratio.

Abstract: A fluid pressure cylinder includes a first cylinder portion and a second cylinder portion disposed in parallel, and a supply-and-discharge port. The first cylinder portion is partitioned by a first piston into a head-side first accumulation chamber and a rod-side second accumulation chamber. The second cylinder portion is partitioned by a second piston into a head-side release chamber and a rod-side drive chamber. Pressurized fluid is supplied to and discharged from the second accumulation chamber and the drive chamber through the supply-and-discharge port. An end of a first piston rod connected to the first piston and an end of a second piston rod connected to the second piston are connected to each other. The first piston includes a communication switching valve switching communication between the first accumulation chamber and the second accumulation chamber, between enabled and disabled.

Abstract: A cylinder actuator includes a body assembly and a piston assembly. The body assembly includes a first cylinder nested concentrically within a second cylinder. The piston assembly slides linearly within the first and second cylinders. The piston assembly includes a first piston assembly end and a second piston assembly end. The first piston assembly end includes first and second pistons. The first piston moves within the first cylinder. The second piston moves within the second cylinder. The piston assembly includes first and second piston rods. The first piston rod extends from the first piston through a first end of the first cylinder. The second piston rod extends from the second piston through a first end of the second cylinder. The piston rods are joined at the second end of the piston rod assembly located outside of the first and second cylinders.

Abstract: A hydraulic pressure amplifier arrangement (1) is described comprising a supply port (A1), a pressure outlet (A2) connected to the supply port via check valve means (3), a tank port (B1), an intensifier section (5) having a high pressure piston (6) in a high pressure cylinder (7) which is connected to the pressure outlet (A2), a low pressure piston (8) in a low pressure cylinder (9) and connected to the high pressure piston (6), an intermediate space (11) between the high pressure piston (6) and the low pressure piston (8), a control valve (12) controlling a pressure in the low pressure cylinder (9), and a feeder arrangement of the intensifier section (5) including an input connection (19) connected to the supply port (A1) and a return connection (20) connected to the tank port (B1). Such a pressure amplifier arrangement should have a simple construction. To this end the feeder arrangement (19, 20) comprises throttling means (21).

Abstract: A steam turbine valve drive apparatus in an embodiment includes a piston, a cylinder, a bidirectional pump, a servo motor, and a quick closing mechanism. The cylinder houses the piston in an inner space thereof, the inner space being partitioned by the piston into a first hydraulic chamber and a second hydraulic chamber. The quick closing mechanism executes a quick closing operation of closing the steam valve unit more quickly than the closing operation. Here, the quick closing mechanism executes the quick closing operation by feeding the working oil accumulated in an accumulator to the second hydraulic chamber and draining the working oil from the first hydraulic chamber.

Abstract: A work machine that can detect abnormality such as a malfunction and wear and tear of each of hydraulic pumps including control equipment with high precision and that can reduce equipment cost is provided. A controller 9 according to the present invention includes a volumetric-transfer-efficiency-calculating section 94 that calculates a volumetric transfer efficiency ?C representing a transfer efficiency of hydraulic oil between a hydraulic cylinder 11 and hydraulic pumps 21 to 23 on the basis of a target discharge flow rate calculated by a target-discharge-flow-rate-calculating section 932 and the speed of the hydraulic cylinder 11 that is detected by a speed sensor 28, and an abnormality decision section 95 that decides whether any one of the hydraulic pumps 21 to 23 is abnormal on the basis of the volumetric transfer efficiency ?C calculated by the volumetric-transfer-efficiency-calculating section 94.

Abstract: A method of actuating an assembly of a transmission, with which are associated a plurality of actuators with whose help the assembly can in principle be actuated, such that out of the actuators available in principle for actuation, a control unit selects at least one actuator for the actual actuation and activates the selected actuator with an output signal in such manner that a status parameter of the actuated assembly corresponds to or follows a control-side nominal value, such that out of the actuators available in principle for actuating the assembly, the control unit selects at least one actuator for the actual actuation of the assembly in such manner that, for all the actuators available in principle for actuating the assembly over the operating life of the transmission, the extent of their utilization is approximately uniform.

Abstract: The invention relates to a hydraulic manifold apparatus and system, connectable to a dual stage motor, for use in the topdrive of drilling operations. The hydraulic manifold is switchable between a low speed, high torque configuration and a high speed, low torque configuration. Valves within the manifold control the flow of working fluid through the manifold and into and out of the motor. Switching means are further provided to control the opening and closing of the valves. In the low speed, high torque configuration, working fluid enters each stage of the dual motor simultaneously, in parallel. In the high speed, low torque configuration, working fluid enters a first stage of the motor, returns to the hydraulic manifold, then enters a second stage of the motor, before returning again to the hydraulic manifold. Thus during high speed, low torque operation, working fluid enters each stage of the dual motor in series.

Abstract: The invention relates to a method and to a working equipment for actuating a hydraulically movable working element (24), which is provided on a main body (14) of a working equipment (11), comprising at least one main cylinder (19) and at least one additional cylinder (28), which are supplied with pressure medium to generate a pivoting movement, wherein the pivoting movement in the rapid motion mode is actuated in a first working pressure range of the hydraulic control device (32), the pivoting movement in a working motion mode is actuated in a second working pressure range, which is higher than the first working pressure range, the pivoting movement in the heavy load motion mode is actuated in a third working pressure range, which is higher than the first and second working pressure ranges, and the pivoting movement of the working element (24) in the operating modes of rapid motion, working motion or heavy load motion is actuated in accordance with the prevailing working pressure.

Abstract: Actuator arrangements are disclosed. An actuator arrangement can include a first fluidic-based actuator device designed to exert a first force on a first location of a body associated with the first actuator device. An actuator arrangement can also include a second fluidic-based actuator device designed to exert a second force on a second location of the body associated with the first actuator device. The distance between the first and second locations can be small. The maximum value of the second force can be less than the maximum value of the first force.

Abstract: Systems and methods for efficiently operating a hydraulically actuated device/system are described herein. For example, systems and methods for efficiently operating a gas compression and expansion energy storage system are disclosed herein. Systems and methods are provided for controlling and operating the hydraulic actuators used within a hydraulically actuated device/system, such as, for example, a gas compression and/or expansion energy system, within a desired efficiency range of the hydraulic pump(s)/motor(s) used to supply or receive pressurized hydraulic fluid to or from the hydraulic actuators. In such a system, a variety of different operating regimes can be used depending on the desired output gas pressure and the desired stored pressure of the compressed gas. Hydraulic cylinders used to drive working pistons within the system can be selectively actuated to achieve varying force outputs to incrementally increase the gas pressure within the system for a given cycle.

Abstract: A hydraulic transmission circuit is provided having at least two elementary hydraulic motors, each having a secondary enclosure and a main duct for fluid feed and a secondary enclosure and a main duct for fluid discharge. A fluid distributor distributes fluid from the main ducts to the elementary motors via the secondary enclosures. A control system controls the elementary motors. Valves connecting the fluid distributor to the secondary enclosures of the first motor put a secondary enclosure into communication with a main duct independent of an operating mode of any other elementary motor.

Abstract: A fluid control or actuation system providing selective recruiting of actuators antagonistic to one another to provide variable output power, such as that used to drive a load. The actuators are intended to comprise different sizes, and to be operable with one or more pressure control valves capable of providing displacement of a non-recruited actuator without requiring active input to cause such displacement. Being able to selectively recruit different sized actuators to drive the load, and being able to displace non-recruited without active input, effectively incorporates a gearing function into the fluid control system.

Abstract: A motor having two series of distribution ducts each having two groups of ducts. The displacement selector is able to occupy a large displacement position in which the first groups of distribution ducts of the first series are connected to a main duct while the second groups are connected to the other main duct, and a small displacement configuration in which the first group of distribution ducts of the first series is connected to a main duct, the second group of distribution ducts of the first series is connected to the other main duct and a bypass connection exists between the first and the second group of distribution ducts of the second series. The device has a restriction in order, in the small displacement configuration, to restrict this bypass connection.

Abstract: A hydraulic transmission system features a first hydrostatic motor (1) and a second hydrostatic motor (4), which are connected to an output shaft (3) by way of a compound transmission, and which, in order to reach a minimum and a maximum rotation speed of the output shaft, are, on the one hand, adjustable with respect to their displacement volume by way of electric valves (9, 17) and, on the other hand, can be connected or, as the case may be, separated from a conveyor line (7) and a suction line (8) of a hydraulic pump.

Abstract: A hydraulic actuator is configured to provide redundant boost control to an aircraft within approximately the same space required by a single hydraulic cylinder. The hydraulic actuator includes a housing and a piston assembly disposed within the housing. The piston assembly includes a ram, a first piston secured to the ram, and second and third pistons disposed on the ram such that the second and third pistons are translatable relative to the longitudinal axis of the ram. The pistons form two hydraulically separate actuator cylinders within the space required by a single cylinder which results in a reduction in the weight and size of the hydraulic actuator.

Abstract: The invention relates to a catapult drive for an object to be accelerated, preferably the car of a fairground ride, wherein the object is accelerated by means of a driving element. The movement of the driving element is produced by a flexible drive and a hydraulic cylinder via which all movements of the driving element can be controlled. The invention also relates to a control system for suitably controlling the inventive catapult drive.

Abstract: A swivel motor has a plurality of work chambers and a join system between the work chambers that joins the work chambers at least by pairs. The arrangement of the joined work chambers is carried out in such a way that the work chambers which are connected to the first pressure medium connection alternate with those which are connected to the second pressure medium connection. At least two work chambers associated with different pressure medium connections are connected to a pressure compensation element, and the pressure compensation element is formed by a compensation space that is divided by a movable dividing element. A partial compensation space is connected in each instance to at least one work chamber of a pressure medium connection, and the dividing element is held in an initial position by oppositely acting springs. The spring force characteristic is formed by a spring arrangement which comprises a plurality of springs and has at least one coil spring and one elastomer spring.

Abstract: A digital hydraulic system including a hydraulic source, a housing and a transtatic bridge. The transtatic bridge being substantially contained within the housing. The transtatic bridge being in fluid communication with the hydraulic source. The transtatic bridge communicating a force to or from a shaft or a fluid.

Abstract: A motor having two series of distribution ducts each having two groups of ducts. The displacement selector is able to occupy a large displacement position in which the first groups of distribution ducts of the first series are connected to a main duct while the second groups are connected to the other main duct, and a small displacement configuration in which the first group of distribution ducts of the first series is connected to a main duct, the second group of distribution ducts of the first series is connected to the other main duct and a bypass connection exists between the first and the second group of distribution ducts of the second series. The device has a restriction in order, in the small displacement configuration, to restrict this bypass connection.

Abstract: A hydraulic control circuit for a radial piston engine with two speeds. The changeover between the speeds takes place through the alteration of the absorption volume, the delivery side being connected to the discharge side with a bypass connection by a valve arrangement for a selected number of engine pistons. The control circuit provides a space-saving way of ensuring that the changeover between speeds occurs smoothly and in such a manner to preserve the individual components as far as possible. To this end, at least one intermediate switching position, in which the delivery side is throttled to the discharge side, i.e. connected by a diaphragm-type arrangement, is provided in front of valve arrangement between the two end switching positions. The valve arrangement is preferably driven such that a valve body can be moved through the intermediate switching position at a controlled speed.

Abstract: A drive for a movable part, such as a mold closure platen, includes two hydraulic cylinder-and-piston units defining first and third pressure chambers in a first of the hydraulic units and defining fourth and fifth pressure chambers in a second of the hydraulic units, and wherein the piston of one of the hydraulic units is a stepped piston defining a second pressure chamber, thereby providing five pressure chambers. An arrangement of valves provides for selective coupling of hydraulic fluid among the pressure chambers whereby pressure medium is forced from one of the hydraulic units, during an advance of its piton, to the other of the hydraulic units.

Abstract: A tandem electrohydrostatic actuator (70) broadly includes a first piston (22) operatively arranged in a first cylinder (23), and a second piston (24) operatively arranged in a second cylinder (25). The pistons are coupled to move together. The first piston has a small extend area (35) and a large retract area (36). The second piston has a large extend area (38) and a small retract area (39). The large areas (36, 38) of the pistons are equal to one another and the small areas (35, 39) of the pistons are equal to one another. A reversible fixed-displacement first pump (45) has equal inlet and outlet flows supplied to the small areas of the first and second pistons, respectively. A reversible fixed-displacement second pump (40) has equal inlet and outlet flows supplied to the large areas of the first and second pistons, respectively. The total volume of the fluid in the actuator remains constant at all positions of the pistons.

Abstract: The present invention includes a hydrostatic transmission system that has a control device that is selectable to send a speed signal to a motor for driving an output at a predetermined speed. A controller is used to automatically permit the selected speed signal in response to a predetermined speed signal and predetermined input from a sensing device indicating that the output is being driven in a forward drive condition. The controller is also used to automatically override the selected speed signal in response to a predetermined speed signal and predetermined input from a sensing device indicating that the output is being driven in a reverse drive condition. This invention allows for the speed of the motor to be changed from a high speed to a low speed when the motor is driving the output in a reverse drive condition to achieve greater efficiency and control of a work machine.

Abstract: Cylinder deactivation apparatus includes switching valve actuators controlled by rotary valve sleeves surrounding each of the actuators. In a preferred embodiment, the sleeves act to admit continuous pressurized oil to internal lash adjuster mechanisms and selectively control oil flow from a lash adjuster mechanism inlet to a deactivator switching mechanism and discharge of pressure oil from the deactivator switching mechanism. A single oil supply provides pressurized oil to both conventional and deactivation valve actuators for lubrication of associated valve mechanisms and operation of internal lash adjusters as well as for operation of the cylinder deactivation mechanisms. In a valve-actuating position, the rotary sleeve drains oil from the deactivating mechanism so that associated engine valves are operated normally.

Abstract: A hydraulic lifting device provides a lifting of the massive objects, having a complex geometric form and includes a support plate rigidly connected to the plungers coupled with the body carrying a main plunger, comprising a main rod and a main hydraulic fluid cavity, a main, auxiliary and central hydraulic fluid channels, a main valve and valve, and wherein each plunger comprises a road and hydraulic cavity.

Abstract: A material eject system includes an ejector mounted to a bed of a vehicle which is movable between a rear end and a forward end of the bed for ejecting material from the bed. The ejector is powered by a cylinder having different fluid volumes depending on the direction of motion of the cylinder. A control circuit operates with the ejector motor to automatically move the ejector through eject and return cycles. Further, the control circuit detects different positions of the cylinder and automatically operates the cylinder at different speeds to maintain a constant motor and ejector speed throughout the material eject cycle.

Abstract: Hydraulic device comprising two hydraulic actuators (1, 2), in particular a motor (2) and a double-acting jack (1), each comprising two couplings (1a, 1b, 2a, 2b) for the entry and/or the exit of a control fluid, two pipes (6, 7) coupled to the two actuators (1, 2) and devised so that one conveys a pressurized fluid to a coupling of each actuator whilst the other discharges the fluid to the other coupling, and vice versa, in such a way that the jack (1) can be controlled in respect of [lacuna] a movement in one direction and in the reverse direction, and a reversing gate for reversing between the two pipes (6, 7) the supplying of pressurized fluid and the discharging of the fluid, so as to control the direction of the movement of the said jack (1), the device furthermore comprising: a means of detection (8) of a difference in pressure between the pressurized fluid and the discharged fluid, and between the reversing gate and the other actuator (2), an auxiliary reversing means (9), devised so as to r

Abstract: A cylinder-capacity selector for a hydraulic motor having at least two active operating cylinder capacities and comprising having at least two main ducts. The selector includes three ports and distribution ducts of the motor to establish selective communication between the main ducts and the cylinders of the motor. When the selector passes between its first and second stable positions, in at least one displacement direction, an intermediate stage exists that is maintained for a lapse of time, during which all three ports are in communication and the section of at least one of the passages between the first and second ports and between the second and third ports of the selector is constricted.

Abstract: A ram actuating mechanism 20 for a blowout preventer 10, the ram actuating mechanism 20 including a hydraulic booster for enhancing the ram closing force. The ram actuating mechanism 20 may be compatible for use with primary pistons 25 which include internal moving components, such as self locking pistons. The ram actuating mechanism 20 providing a hydraulic booster without increasing the diameter of the booster pistons above the diameter of the primary piston, such that BOP stack height need not be increased to accommodate a relatively large diameter hydraulic booster. The ram actuating mechanism 20 may utilize the same piston housing 60 as used by the primary piston, and the booster pistons 26, 28 may act mechanically in series upon the primary piston 25 to increase axial ram closing force. The ram actuating mechanism 20 may be capable of retro-fitting existing ram actuating mechanisms.

Abstract: What is disclosed is a method for controlling a hydraulic cylinder acting against a load, and a hydraulic installation of a utility vehicle operating in accordance with this method, wherein the pressure in the supply line to the effective areas of the hydraulic cylinder is maintained at a level that approximately corresponds to the pressure level in a hydraulic accumulator for supplying the hydraulic installation.

Abstract: An automatically operable negative pressure type booster can be applied for a front stage pressurizing function in a braking fluid pressure control apparatus with braking and steering control. The booster includes a housing, a movable wall dividing the housing interior into a front chamber and a rear chamber, a valve housing outputting a braking force to an output rod, an input member, and a control valve. The output rod can be divided into a first member and a second member. The booster further includes an auxiliary movable wall which can be engaged with the first member, a partition wall forming an auxiliary variable pressure chamber behind the auxiliary movable wall, and an electromagnetic valve unit selectively communicating the auxiliary variable pressure chamber with the front chamber or atmosphere.

Abstract: Disclosed is an apparatus for a derrick, including hydraulic piston/cylinder arrangements for raising and lowering a yoke travelling on guide rails attached to the derrick. A hydraulic system having different modes of operation is provided for the operation of the piston/cylinder arrangements. The hydraulic system can operate in a normal mode for raising or lowering the yoke and in other modes by interconnecting upper and lower chambers of the piston/cylinder arrangements and utilizing a differential surface area of the piston exposed to the two chambers for rapidly raising or lowering the yoke.

Abstract: The invention relates to an improved hydraulic quick lifting unit used in a jack, especially to improvements made on the valves of the hydraulic system, a fastener assembly and an oil return tube of the lifting shaft. The hydraulic system can return hydraulic liquid to the outer oil reservoir in a slow rate when the lifting shaft according to the invention bears a load. Thus the lifting shaft moves down slowly. When the load on the lifting shaft is removed, the hydraulic liquid flows back to the outer oil reservoir in a larger quantity in a short time. Hence the lifting shaft can quickly return to the its original position. Further, the fastener assembly is located between the lifting shaft and the mandrel, which has the advantages of enhancing the accuracy of the clearance between the mandrel and the inner oil reservoir of the lifting shaft, and preventing the positional shift of the mandrel in the inner oil reservoir. The invention has the benefit of enhancing the stability of product performance.

Abstract: For supplying a large volumetric flow into a particular hydraulic actuator without requiring a directional control valve to be large-sized and without making large a pressure difference between a pump discharge pressure and a load pressure or reducing the pressure loss when a large volumetric flow is flushed out into a tank, a flow control apparatus in a hydraulic circuit is designed to supply a pressurized discharge fluid from the hydraulic pump (10) via a directional control valve (15) and a pressure compensation valve (18) to a plurality of hydraulic actuators (16) which are arranged in parallel to one another, the apparatus in its construction including an auxiliary control valve (30) for supplying the pressurized fluid to a particular one of the hydraulic actuators (16), which is supplied with the pressurized discharge fluid from the hydraulic pump (10) via the said auxiliary directional control valve (30) and the directional control valve (15), or whose return fluid out of that particular hydraulic actu

Abstract: A high speed and high load operable hydraulic drive cylinder system comprises a principal cylinder (3) with a piston (3a)) defining an upper and a lower chamber (3c, 3d) and a piston rod (3b), and a subsidiary cylinder (2) smaller in pressure receiving area than the principal cylinder and a piston (2a) defining an upper and a lower chamber (2c, 2d) and a piston rod (2b) smaller in diameter than the piston rod (3b).

Abstract: The energy conversion system of the subject invention converts the energy from a source of pressurized fluid, such as a free-piston engine and a storage accumulator, to a work system at various pressure levels. This is accomplished by providing power modifying units which act to efficiently reduce the pressure level of the fluid from the source of pressurized fluid to the various pressure levels. A control arrangement monitors the operating pressures in the actuators and selects the path of pressurized fluid having the lowest pressure level needed to perform the task. Additionally, exhausted fluid containing energy is utilized by regenerating the fluid back to the inlet of the actuator or by directing it through the appropriate power modifying unit to amplify the pressure therein and supplement or recharge the source of pressurized fluid.

Abstract: A high speed safety circuit arrangement is provided for a hydraulic press which is driven by a hydraulic cylinder assembly constituted by a principal cylinder unit and a subsidiary cylinder unit. The circuit arrangement comprises a servo valve disposed in one of at least a pair of conduit lines for supplying a pressure fluid from a source thereof into the principal cylinder unit and the subsidiary cylinder unit, a first logic valve disposed in the other of the conduit lines and switched on and off and by the servo valve and a first electromagnetic valve for opening and closing that other conduit line, a second and a third logic valve of which each is switched on and off, and at least one is selectively actuatable, by a second electromagnetic valve to interconnect an upper and a lower chamber of the principal cylinder unit in a hydraulic circuit.

Abstract: A press assembly includes a hydraulic cylinder assembly having first and second chambers and respective piston and rod assemblies therein. The rod of the second assembly is arranged to enter the first chamber and thereby raise the pressure therein. Initially, fluid flows into the first chamber, forcing the first rod to exert a force on a work object. When a predetermined pressure is reached within the cylinder, fluid is introduced to the second chamber, and causes the second rod to move into the first chamber, which raises or boosts the pressure in the first chamber.

Abstract: A hydraulic tool having a ram or other working element propelled by pressurized fluid. The tool has a lever which is squeezed to develop fluid force in a pump. The fluid circuitry automatically operates the ram selectively at any one of three operating speeds and hence at three different magnitudes of force relative to the input speed of the lever as it is squeezed. The circuitry includes a principal supply subcircuit in which fluid flows directly from the pump to the ram, thereby establishing a normal speed mode of operation. A high speed subcircuit and a low speed subcircuit each operated by respective pressure responsive valves direct fluid ejected as the ram piston and pump piston advance to the respective rear sides of the ram piston and pump piston.

Abstract: A radial-piston hydraulic motor and method for regulating a radial-piston hydraulic motor including one or more cylinder groups, each cylinder group having piston mechanisms that move radially back and forth. The piston mechanisms include a piston and a press wheel. The volume per revolution of the motor can be changed in one or more stages so that the press wheels of one or more of the piston mechanisms come out of contact with a cam ring. The hydraulic motor also includes a closing valve for closing the flow of working pressure to one or more of the piston mechanisms.

Abstract: A variable-speed rotating drive is provided. A drive shaft terminates in a hreaded piston that is received in an internally threaded cylinder. A plurality of linear actuators are distributed evenly about the circumferential periphery of the internally threaded cylinder. The drive shaft is mechanically coupled with each shaft of the linear actuators so that axial movement of the linear actuators' pistons causes the threaded piston to move axially in the internally threaded cylinder. This brings about axial rotation of the internally threaded cylinder. An actuating source is coupled to the linear actuators to cause the axial movement of selected ones of the pistons based upon the desired speed of rotation of the internally threaded cylinder.

Abstract: A hydrostatic bridge including two hydraulic motors each having two distinct operating cylinder capacities, both motors sharing an overall casing. The bridge has four main ducts of a first type (feed or exhaust) and two main ducts of a second type (exhaust or feed). The overall casing has three upstream ducts respectively connected to the first and second main ducts of the first type themselves connected to distribution ducts of the first motor, to third and fourth main ducts of the first type, themselves connected to distribution ducts of the second motor, and to first and second main ducts of the second type, themselves connected to distribution ducts of both motors. The bridge includes an anti-spin device capable of selectively reducing the flow rate in the first upstream duct and in the second upstream duct for selectively correcting spin of the first and second motors.

Abstract: In a hydraulic operating mechanism for a convertible top, a pressure sensor (12) is incorporated into a common pressure circuit (P) of the hydraulic cylinders (1 through 4) and connected with a control unit which is connected to the switching elements (V1 through V4) of the hydraulic cylinders (1 through 4), and its output signal in relation to time, together with the preset switching sequences of the individual switching elements (V1 through V4), serves to control the end positions of the individual hydraulic cylinders (1 through 4). The control can thus be incorporated in the operating mechanism without expensive separate end position switches at each hydraulic cylinder (1 through 4) or appurtenant actuation element, simplifying the overall design.

Abstract: An apparatus generates power at micro-scale dimensions that is sufficient to simulate the muscle activity required by the joints of robotic fingers. The apparatus includes a bellows device for generating a motion stimulus in response to pressure changes within the bellows. A configuration of programmable micromachined valves is used to regulate the flow of pressurized fluid within the bellows. A microprocessor is responsive to motion commands for controlling the operation of the apparatus. The apparatus is configured as an integrated device that is coupled to the articulations of a robotic hand via suitable attachment mechanisms.

Abstract: A control system for controlling the movement of the ram of a press or press brake of the type having one or two main cylinders with pistons operatively attach to the ram. The control system comprises a programmable processor with inputs from a pressure transducer indicating the pressure applied to the one or two pistons and a linear potentiometer for each side of the ram to indicate ram position and levelness. The control system further includes a hydraulic circuit operated by outputs from the processor. The hydraulic circuit comprises a variable volume load sense-controlled pump supplying hydraulic fluid through a speed control assembly to a solenoid-actuated directional valve determining upward and downward movement of the ram. The speed control assembly comprises at least two lines connected to the output line of the pump and to the speed control assembly output line to the directional valve. At least one of the at least two speed control assembly lines is provided with a restricting orifice.

Abstract: A system and method for controllably positioning a hydraulic actuator which is operably connected to a control surface includes at least one main control valve for controlling the hydraulic pressure supplied to the actuator in response to a control signal indicative of a predetermined actuator position and at least one parallel control valve for supplying additional hydraulic pressure to the actuator in response to an error signal indicative of the difference between the position of the actuator and the predetermined actuator position to thereby correct for any differences indicated by the error signal. By correcting for any differences indicated by the error signal, the errors in positioning the control surface can be decreased and the stiffness of the control surface can be increased.

Abstract: A fluidic actuator includes dual-element, differential area pistons consisting of a power piston and an extender piston that are mounted in a double-chamber cylinder. A spring-loaded throttling plunger is slidingly mounted in a longitudinal bore in the power piston to meter the flow of pressurized fluid against to the extender piston as a function of the incremental stroke length of the extender piston.

Abstract: A high speed and high load cylinder device is constructed by connecting a piston of a high speed cylinder (1) having a smaller pressure receiving area and a piston of a pressurizing cylinder (2) having a large pressurizing area. The device is provided with a hydraulic circuit for supplying a hydraulic pressure to the high speed cylinder and the pressurizing cylinder. The device has a sequence valve (5) at an intermediate position in a passage (2e) providing in the piston of the pressurizing cylinder for communicating an upper chamber (2.sub.1) and a lower chamber (2.sub.2) of the pressurizing cylinder for opening and closing the passage depending upon a pilot pressure. A pilot pressure is supplied for closing the sequence valve by supplying the pilot pressure to the sequence valve. A high speed/pressurizing switching valve (12) is provided at an intermediate position in a piping (11) supplying the hydraulic pressure to the upper chamber of the pressurizing cylinder in the hydraulic circuit.