Abstract: A landing gear lifting/lowering EHA system includes: a hydraulic actuator configured to lift and lower the leg of an aircraft; at least one electrically operated hydraulic pump; a hydraulic path; a pressure sensor attached to the hydraulic actuator or the hydraulic path and configured to output a measurement signal corresponding to hydraulic pressure; and a controller configured to output a control signal to the electrically operated hydraulic pump, wherein, when a state in which the hydraulic pressure exceeds a set pressure continues for a set time, the control unit stops the electrically operated hydraulic pump in operation and resumes the operation of the electrically operated hydraulic pump after the hydraulic pressure drops to or below a second set pressure after the electrically operated hydraulic pump is stopped.

Abstract: A tool device for expanding the end of a tube (T) includes an expansion sleeve element made of elastomeric material, the expansion sleeve element being arranged concentrically around a pull rod. A calibration sleeve is arranged concentrically around the expansion sleeve element. The inner die surface of the calibration sleeve comprises a mouth portion which has a fourth diameter (d4) which corresponds with a play to the outer diameter of the tube (T), at least one expansion die portion having a fifth diameter (d5, d6) which is larger than the fourth diameter (d4), and a shoulder between the mouth portion and the expansion die portion. The shoulder keeps the end of the tube (T), while being expanded, stationary in place inside the calibration sleeve.

Abstract: The invention relates to a hydraulically actuated piston (9) guided in a cylinder (8), and to a hydraulic working tool (1) having a working head (2), wherein the piston (9) has an impact surface (15) which borders an impact space (16) on the piston side provided between the piston (9) and the cylinder (8), and wherein hydraulic fluid (17) can act on the impact surface (15) by increasing the impact space (16) in order to move the piston (9) in an impact direction (r), and the piston (9) forms a limiting device (25) for a through-flow of the hydraulic fluid (17).

Abstract: A fluid pump for a linear actuator causes a rod in the actuator to extend or retract by controlling fluid flow to and from portions of a fluid chamber on either side of a piston disposed within the fluid chamber and supporting the rod. The pump includes check valves that control fluid flow between a driven pump element and each portion of the fluid chamber and a shuttle movable in response to fluid pressure along a shuttle axis extending through the valves. At least one valve includes a valve member movable between a closed position and an open position defining a fluid flow path between the driven pump element and fluid chamber and means for limiting movement of the shuttle towards the valve such that the shuttle may, depending on the position of the limiting means, move the valve member to an intermediate position between the closed and open positions.

Abstract: An example tool includes a housing; an inclined handle coupled to, and extending obliquely from, a top portion of the housing, where the inclined handle has a first trigger button and a second trigger button; and an interlocking mechanism disposed in the inclined handle. The interlocking mechanism is configured to disable one of the first trigger button or the second trigger button while the other of the first trigger button or the second trigger button is triggered.

Abstract: An example tool includes a housing; an inclined handle coupled to, and extending obliquely from, a top portion of the housing, where the inclined handle has a first trigger button and a second trigger button; and an interlocking mechanism disposed in the inclined handle. The interlocking mechanism is configured to disable one of the first trigger button or the second trigger button while the other of the first trigger button or the second trigger button is triggered.

Abstract: A crimp tool having jaw members joined in a tongue-in-groove connection held in place by a locking pin. Each jaw member being tapered and including weight reducing pockets defined in respective sidewalls. Each jaw member includes a locking tab on an outside edge that mates with a respective locking tab opening in the neck of the tool. When the locking pin is removed, the jaws of the tool separate and rotate away from one another until their respective locking tabs engage their respective locking tab opening, thereby holding the opened jaws in the neck of the tool.

Abstract: Hydraulic tools having extendable rams for performing various functions such as crimping are described. The tools include a hydraulic system that enables the ram to be rapidly advanced. Methods using the hydraulic systems and tools are also described.

Abstract: A hydraulic energy recovery system (101) has an output drive unit (103), which can be actuated by a driver (102), and by which a hydraulic motor-pump unit (104) can be driven. In at least one energy feed position, the motor-pump unit supplies an energy storage device (106) and/or working hydraulics (107) with fluid. In a recuperation position, the motor-pump unit discharges fluid under pressure from the energy storage device (106) at least to the working hydraulics (107) and/or is used to actuate the output drive unit (103).

Abstract: An electrically-hydraulically powered riveter and lockbolt hand power tool is provided, having a battery driven electric motor mechanically powering an offset drive cam through a dual planetary drive gear, the drive cam being in direct mechanical contact with a single stage concentrically delivering longitudinally reciprocating piston pump being in direct hydraulic communication with a work engaging hydraulic cylinder surrounding a centrally fixed and stationary work engaging cylinder piston having a work piece puller shaft, wherein the work engaging hydraulic cylinder is thrust forward around the work piece puller shaft when the tool is activated thereby providing the mechanical motion to activate a user provided riveter nose assembly attachment. A multi-function valve provides essential hydraulic pump features integrated into a single simple component including over pressure relief, isolation of the work engaging cylinder cavity during pumping, and venting when the tool is deactivated.

Abstract: A hydraulic drive device for cargo handling vehicle has: a tank; a pump for drawing in a hydraulic oil from the tank and supplying the hydraulic oil to hydraulic cylinders; an electric motor for driving the pump; a solenoid-controlled proportional valve disposed between an inlet port of the pump and a bottom chamber of an up-and-down hydraulic cylinder and configured to open with a valve travel depending upon a control input of a descent control of an up-and-down control member; a pressure compensation valve disposed between a branch portion located between the pump and the solenoid-controlled proportional valve and the tank and configured to open with a valve travel depending upon a pressure difference between pressures upstream and downstream of the solenoid-controlled proportional valve; and a valve disposed between the pressure compensation valve and the tank and configured to be switched between an open position and a close position.

Abstract: A clutch assembly includes a fluid-actuated piston that allows clutch usage in both high pressure and low pressure applications. The configuration of the clutch assembly is usable with both hydraulic and pneumatic pressure actuation. Seal configurations create differently sized internal piston surface areas against which inlet pressure applied at hydraulic or pneumatic fluid inlet ports act to move the piston. The utilization of differently sized piston surface areas allows the piston to apply essentially the same clutch engaging compression force in both high pressure hydraulic actuation and lower pressure pneumatic actuation applications.

Abstract: A hydraulic modulator including a motor having a motor housing, a stator, a rotor, and a motor shaft. A power transmitting mechanism is provided for transmitting the power of the motor to the outside thereof. A master cylinder includes a piston linearly movable by the power transmitted by the power transmitting mechanism. The master cylinder is arranged so as to overlap the motor housing in such a manner that the axis of the master cylinder is substantially perpendicular to the axis of the motor shaft. The master cylinder is arranged on one side of the motor housing in the range corresponding to the axial length of the motor shaft. The length of the hydraulic modulator along the motor shaft falls within the axial length of the motor shaft, so that the hydraulic modulator can be reduced in size.

Abstract: A hydraulic arrangement for the activation of two actuators, with a hydraulic pressure supply unit which is assigned jointly to the two actuators. The pressure supply unit is designed to be reversible in its direction of action, so that, depending on the direction of action, in each case only one of the actuators is driven.

Abstract: An electrically-hydraulically powered rivet setting and crimping hand power tool is provided, having a battery driven electric motor mechanically powering an offset drive cam through a dual planetary drive gear, the drive cam being in direct mechanical contact with a dual volume, dual stage concentrically delivering longitudinally reciprocating piston pump being in direct hydraulic communication with a work engaging hydraulic cylinder surrounding a centrally fixed and stationary work piece puller shaft, wherein the work engaging hydraulic cylinder is thrust forward around the work piece puller shaft when the tool is activated thereby providing the mechanical motion to activate a user provided riveter nose assembly attachment.

Abstract: An electro hydrostatic actuator includes a single-rod cylinder having fixed and movable ends, a hydraulic supply source, and a reservoir provided in a hydraulic circuit and capable of storing operation oil. At a predetermined position of the single-rod cylinder close to the fixed end, the hydraulic supply source is disposed at the periphery of the single-rod cylinder, and is integrated with the single-rod cylinder. The reservoir is formed in a double cylindrical shape, and is, at a position close to the movable end relative to the hydraulic supply source, integrated with the single-rod cylinder in the state in which the single-rod cylinder is inserted into the reservoir so as to be coaxial with the reservoir.

Abstract: A boom construction for truck-mounted concrete pumps has at least a first boom arm and a second boom arm that are articulatedly jointed to each other and that are rotatable relatively to each other about an axis. A drive pivots the boom arms. A piston-cylinder arrangement and a gear transform piston reciprocating movement into rotary movement for boom arm pivoting, said arrangement having first and second pistons that form part of the gear and that interact with outer rings of the gear.

Abstract: A hydraulic system for a vehicle powertrain includes a module including a clutch, an electric machine and a first sump, a transmission including a line pressure source and a second sump, and a pump that supplies fluid from the first sump to the line pressure source when the source of line pressure is unavailable, and supplies fluid from the first sump to the second sump when fluid volume in the second sump is low.

Abstract: The present invention discloses a universal hole cutter in the field of mechanics, comprising an oil pump body, an oil cylinder and an oil storage chamber, in which the oil pump body could be fixedly connected with the oil storage chamber and the oil paths thereof could be communicated with each other. A pressure mechanism could be provided on the oil pump body for pressing the power oil within the oil storage chamber into the oil cylinder. The oil cylinder could be fixedly threaded with a pipe joint communicating with the internal cavity of the oil cylinder, and the pipe joint could be communicated with the oil pump body through a rigid movable linkage mechanism which could rotate the oil cylinder with respect to the oil pump body. Compared to the prior art, in the universal hole cutter thus described, the thread connection of the pipe joint and the oil cylinder is reliable and convenient.

Abstract: An energy storage system is disclosed for use in a hydraulic system for moving a structural member such as a boom assembly. The system features at least one work cylinder and an additional energy storage cylinder that assists in raising and lowering functions by storing and withdrawing pressurized fluid from an accumulator. The pressurized fluid in the accumulator may be used for raising operations as well as digging and tamping operations. Further, the energy recovery features may be selectively disconnected during either a raising or lowering operation.

Abstract: A hydraulic control system is disclosed for use with a machine. The hydraulic control system may have a pump, a tank, and an actuator. The hydraulic control system may also have at least a first valve configured to control fluid flow between the pump, the tank, a first chamber of the actuator, and a second chamber of the actuator; a second valve fluidly disposed between the second chamber and the tank; and a third valve fluidly disposed between the first and second chambers. The hydraulic control system may further have a controller configured to selectively cause the second valve to block fluid flow from the second chamber of the actuator to the tank, and to selectively cause the third valve to fluidly communicate the first and second chambers of the actuator when the second valve blocks fluid flow from the second chamber of the actuator to the tank.

Abstract: A fluid pressure cylinder (3) is connected to a discharge port (24) of a fluid pressure pump (2). A suction port (25) of the fluid pressure pump (2) is connected to a tank (10) via a suction passage (11) in which a flow restrictor (15) is provided. A change-over valve (4) changes over operation modes of the fluid pressure cylinder (3) between a load mode in which the pressure cylinder (3) is driven by the fluid pressure pump (2) and an unload mode in which the fluid pressure cylinder (3) elongates and contracts according to an external force exerted thereon in response to a differential pressure between the discharge port and the suction port. Automatic change-over of the operation modes of the pressure cylinder (3) in response to an operation of the fluid pressure pump (2) is thereby realized.

Abstract: Systems and methods for real-time efficiency and aircraft performance monitoring and delta efficiency calculations between various user- or system-selected phases of flight by determining an efficiency messaging index that gets translated into a messaging profile. That messaging profile is then used to obtain necessary flight and other information from multiple sources. The efficiency calculations and deltas can be used to determine real-time or post-processed benefits, which can then be used to optimize flight(s). Additionally, data is post-processed, which allows the calculation, storage and subsequent usage of efficiency coefficients to enhance the accuracy of the efficiency calculations. There are a number of ways to implement the architecture and order of processing.

Abstract: A hydraulic arrangement for regulating a lifting mechanism (12) of an agricultural machine (10) is described. The hydraulic arrangement (16) comprises a hydraulic cylinder (24) having a chamber (50) capable of being acted upon by pressure, a proportionally adjustable inflow valve (22) which is connected on the outlet side via an inflow line (30) to the chamber (50) and which is connected on the inlet side to a hydraulic pump (18, 18?), a first outlet line (32) which makes a connection between the chamber (50) and a hydraulic tank (20), adjustment means (42, 44) for generating an adjustment signal for the hydraulic cylinder (24), and an electronic control unit (40).

Abstract: An electric circuit with speed control and diode separation for use with an electrically actuatable mechanism. An operator input provides a signal to a controller of the electric circuit. The controller causes a MOSFET relay to provide a voltage to the electrically actuatable mechanism. The relay is adapted to vary the voltage in response to pulse width modified signals from the controller.

Abstract: A pump receiver housing of a hydraulically operated pressing apparatus designed in a compact and lightweight manner and that connects a drive unit to a piston cylinder unit and to a press unit. A piston pump assembly is connected to a pump flange pressed directly onto a connection cylinder of the piston-cylinder unit. The connection cylinder projects through a pump lead-through in the housing wall into the pump receiver housing, and directly contacts on the pump piston. Thus, the pump receiver housing is designed without conduits, so that an inside of the pump receiver housing is free of or has no high pressure.

Abstract: A cylinder device (1) according to the present invention includes: a cylinder (2); a piston (3) slidably inserted into the cylinder (2); a rod (4) inserted into the cylinder (2) and connected to the piston (3); a rod-side chamber (5) and a piston-side chamber (6) partitioned by the piston (3) within the cylinder (2); a first on-off valve (9) provided in the middle of a first passage (8) allowing the rod-side chamber (5) to communicate with the piston-side chamber (6); a second on-off valve (11) provided in the middle of a second passage (10) allowing the piston-side chamber (6) to communicate with the tank (7); and a pump (12) for supplying liquid to the rod-side chamber (5).

Abstract: The invention relates to a hydraulic aggregate, particularly for supplying conveyor and lifting devices with pressurized fluid, having a tank (1) on the end side relative to a main axis of the device and functional components mounted thereon, comprising at least one hydraulic pump (5) and one coupling body (3) having a valve device and a line arrangement for drawing in and returning hydraulic fluid to and from the tank (1), characterized in that it is configured as a reversing aggregate, wherein the inlet end (19) of the suction line (15) of the line arrangement is disposed at a location within the tank (1) where the bottom of the fluid present in the tank (1) is located when the aggregate is operated with the main axis vertical and when the aggregate is operated with the main axis tilted relative to the vertical, preferably perpendicular to the vertical.

Abstract: The invention relates to a positively engaging shifting element which can be hydraulically or pneumatically actuated, comprising a hydraulically or pneumatically actuatable piston (I) having a piston compartment (2) containing a hydraulic medium or pressure medium, a pressure medium supply (6) for the piston (I), a jaw (3) and a mating jaw (4) with which the jaw (3) meshes when engaged. The engaging speed of the jaw (3) can be increased by decoupling the jaw (3) from the hydraulic or pneumatic volume flow when the jaws (3) and (4) are in a tooth butt position in relation to each other and by pretensioning the jaw (3) by means of a hydraulic or pneumatic pressure reservoir (7) that is actively connected to the piston (I) and that is connected to the pressure medium supply (6). The gap between the jaws, i.e.

Abstract: A hydraulic actuator includes, but is not limited to a first outflow and a second inflow and outflow as well as a closure device for closing the second inflow and outflow in the direction of outflow. The first outflow an outflowing hydraulic fluid is subjected to flow resistance. When a switching position is reached, the second inflow and outflow is closed in the direction of outflow so that the hydraulic fluid has to be discharged through the first outflow while overcoming the flow resistance. This damps the movement of the hydraulic actuator in the region of an end position.

Abstract: A hand-held hydraulic tool including a hydraulic drive system comprising a pump; and a user control system for at least partially controlling operation of the hydraulic tool. The user control system includes a first user control at a first location having a first pump activation control switch and a first hydraulic drive system drain control switch, and a second user control at a second location having a second pump activation control switch and a second hydraulic drive system drain control switch. The hydraulic tool is adapted to be controlled by a user at either of the first or the second locations.

Abstract: A hydraulic system for use with a pressurized fluid includes a first cylinder and a second cylinder. A flow path links the first and second cylinders in fluid communication with each other. A first piston is disposed within the first cylinder and defines a first axis and a second piston disposed within the second cylinder. The first piston is movable along the first axis between a variety of operating positions and a rephasing position. The first piston has an exterior surface that defines a peripheral groove and several flutes. The flutes are oriented such that they are parallel to the first axis and intersect the peripheral groove, allowing the fluid to flow from the first cylinder across the flow path and into the second cylinder when the first piston is in the rephasing position thereby automatically rephasing the first and second pistons within the hydraulic system.

Abstract: A hydraulic jack system is described, suitable for lifting heavy loads such as automobiles. The jack system is operable by a powered driver fitted with a socket for coupling to a nut rotationally fixed to the jack system, wherein the driver is removable directly after use. As such, no handle is required for activating the hydraulic jack system. The jack system has a low profile, reducing the danger of being accidentally knocked into during operation. When operated by a powered driver, the driver rotates a camshaft mounted to the jack system, the camshaft reciprocally drives a push rod that activates a plunger for hydraulically elevating a piston ram.

Abstract: A hydraulic jack including a frame and a pump connected to the frame. The pump includes a rod, a housing, a piston and a plurality of valves. The rod has a cross-sectional area. The housing has an end through which the rod slides. The piston is associated with said rod, with the piston establishing a rod side chamber and a piston side chamber within the housing. The piston having a cross-sectional area. The plurality of valves each are fluidly connected to the rod side chamber and/or the piston side chamber. The piston, the rod and the valves are arranged to provide a first hydraulic fluid flow associated with the cross-sectional area of the piston until a predetermined pressure is reached and a second hydraulic fluid flow associated with the cross-sectional area of the rod after the predetermined pressure is reached.

Abstract: A hydraulic arrangement for regulating a lifting mechanism (12) of an agricultural machine (10) is described. The hydraulic arrangement (16) comprises a hydraulic cylinder (24) having a chamber (50) capable of being acted upon by pressure, a proportionally adjustable inflow valve (22) which is connected on the outlet side via an inflow line (30) to the chamber (50) and which is connected on the inlet side to a hydraulic pump (18, 18?), a first outlet line (32) which makes a connection between the chamber (50) and a hydraulic tank (20), adjustment means (42, 44) for generating an adjustment signal for the hydraulic cylinder (24), and an electronic control unit (40).

Abstract: A hydraulic tool including a frame; a ram movably connected to the frame; and a hydraulic drive system on the frame for moving the ram on the frame by hydraulic pressure. The hydraulic drive system includes an automatic release system for automatically releasing hydraulic fluid from the hydraulic drive system. The automatic release system comprises a first valve which is adapted to be automatically opened by a predetermined hydraulic pressure and a second valve which is adapted to be opened by hydraulic fluid passing through the first valve.

Abstract: A hand-held, battery-powered, hydraulically-actuated tool including a frame forming a tool longitudinal axis; a battery offset from the tool longitudinal axis; and located along the tool longitudinal axis a motor connected to the battery; a hydraulic fluid pump connected to the motor, such as by a transmission; a ram movably connected to the frame and adapted to be moved relative to the frame by hydraulic fluid pumped by the hydraulic fluid pump; and a working head adapted to be actuated by the ram. The tool includes a main section situated in an in-line configuration along the tool longitudinal axis. A center longitudinal axis of the battery is offset from the tool longitudinal axis.

Abstract: The invention relates to a fluid linear drive having a cylinder (1) which is entirely or partially filled with a pressure medium. A piston (2) is arranged inside said cylinder so as to be displaced and has a piston rod (10) which is arranged at one end of the piston (2) and is led out of the cylinder (1) in a scaling manner. The piston subdivides the interior space of the cylinder into a first chamber (6) and a second chamber (7), the piston rod (10) extending through the second chamber (7). A pump (17), which is particularly reversible and by means of which the pressure medium can be pumped into the first chamber (6) and pumped off from the first chamber (6), has a first intake and/or pressure connection (18) and a second intake and/or pressure connection (19). The first intake and/or pressure connection of the pump (17) is connected to the first chamber (6) and the second intake and/or pressure connection is connected to a storage chamber.

Abstract: A hydraulic tool including a motor; a hydraulic pump comprising only one reciprocating piston pump member; and a transmission connecting the motor to the hydraulic pump. The transmission includes a wobble plate and at least one spring. The wobble plate includes a front end pivotably connected to a frame of the pump. A rear end of the piston pump member is located against the front end of the wobble plate. The spring is spaced from the piston pump member and applies a biasing force against the front end of the wobble plate.

Abstract: The load dependent, variable displacement, at least three-shift hydraulic mechanism includes a hydraulic device disposed at the front side of a valve block and adapted to move a ram piston oriented such as to raise weight, the hydraulic device defining an oil accumulation chamber, a rapid-lifting oil chamber for rapid extension of the ram piston under no-load conditions, and a high-pressure oil chamber for lifting the ram piston oriented to raise weights, a pump piston apparatus disposed at the back side of the valve block and defining a front working chamber and a rear oil accumulation chamber, and oil passages so arranged that hydraulic oil can be supplied from the oil accumulation chamber and the rear oil accumulation chamber to the front working chamber and then to the rapid-lifting oil chamber or the high-pressure oil chamber to extend the ram piston.

Abstract: An electrohydraulic pressing device is suitable for one-handed operation. The device includes a housing having a working head attached thereto, an electric motor provided within the housing for actuating the working head, the electric motor being rearward of the working head, an actuating switch for actuating the working head, a rearward switch provided within the housing rearward of the motor; and a lever extending from the actuating switch to the rearward switch. The lever is within the housing and the housing around the lever forms a gripping region. When the actuating switch is actuated, the lever is moved to actuate the rearward switch.

Abstract: A hydraulic system is disclosed. The hydraulic system includes an actuator including a first, a second, and a third fluid chamber. The hydraulic system also includes a high pressure source of pressurized fluid in selective fluid communication with the first and second fluid chambers. The hydraulic system also includes a low pressure source of pressurized fluid in selective fluid communication with the first and second fluid chambers. The hydraulic system further includes a hydraulic motor in fluid communication with the third fluid chamber.

Abstract: A hydraulic motor with rotating shaft coupled to a piston with alternating rectilinear displacement. The hydraulic motor comprises a casing enclosing a rotating shaft, a piston and an inverter comprising a first sleeve formed as one piece with the piston, a second sleeve, fixed in position, and a distributor mounted so as to rotate in the interior of the second sleeve and conduit and hole elements arranged between the second sleeve and the distributor and means for controlling the rotation of the distributor as a function of the displacement of the first sleeve so as to invert the direction of displacement of the piston.

Abstract: In order to increase the pressure of the hydraulic medium in cylinders, especially those of the hydraulic longwall construction used in underground mining and tunnel construction, a control unit 21 is used which has suitably controllable, releasable check valves 29, 30 and 25, as well as a blockable check valve 31. These check valves and the associated directional valves create the possibility of filling both the cylinder space 20 proper and the piston rod cavity 26, which enables the pressure adjustment process with hydraulic medium in a specific manner, or accordingly their discharge, with no risk of reciprocal influence, seizing, or other damage.

Abstract: A chair elevating/lowering hydraulic device includes at least a foot pump 3 which absorbs oil by an ascent of an operation lever 1, which discharges oil stored by a stepping-on of the operation lever, and which discharges stored oil by a stepping-on of the operation lever to a lowest position, a check valve 5 which is opened by the oil pressure of the oil discharged from the foot pump, which is opened when the foot pump is lowered to the lowest position, and which allows the oil from the non-return side to pass to allow it to return to an oil tank through the foot pump, an elevating/lowering cylinder 7, and an accumulator 6.

Abstract: The invention relates to an electrohydraulic pressing device (1) that can be operated using one hand. The device comprises a working head (30), an electric motor (4), a pump (20), a hydraulic reservoir (33), and a gear mechanism (19) extending between the electric motor (4) and the pump (20). A holding area (5) around which a hand is placed is provided and an actuating switch (39) is assigned to this area. The aim of the invention is to improve a pressing device of this type with regard to the handling thereof. To this end, the invention provides that the holding area (5) is formed around the electric motor (4), and the actuating switch (39) is situated between the electric motor (4) and the working head.

Abstract: A battery powered hydraulic tool including a frame; a battery connected to the frame; a motor connected to the frame and adapted to be powered by the battery; and a hydraulic pump connected to the motor by a gear reduction transmission. The motor and gear reduction transmission are adapted to output a torque of the least about 160 oz-in with the gear reduction transmission being adapted to provide a gear reduction of between about 8:1 to about 15:1 or less, and the hydraulic pump being adapted to output at least about 6000 psi of pressure or more.

Abstract: A battery powered hydraulic tool including a frame; a battery connected to the frame; a motor connected to the frame and adapted to be powered by the battery; and a hydraulic pump connected to the motor by a gear reduction transmission. The motor and gear reduction transmission are adapted to output a torque of the least about 160 oz-in with the gear reduction transmission being adapted to provide a gear reduction of between about 8:1 to about 15:1 or less, and the hydraulic pump being adapted to output at least about 6000 psi of pressure or more.

Abstract: A hydraulic tool is provided with a spool valve 24 for changing the flow of a working fluid pressurized by a hydraulic power generating mechanism in a hydraulic circuit. The spool valve 24 is slidable in directions perpendicular to a piston rod 18. A cylindrical grip handle 34 to be operated by the operator's hand is extended parallel to the piston rod 18 on the outer surface of the main casing 5 so as to be turnable about its own axis. The spool valve 24 and the grip handle 34 are interlocked by a cam mechanism including members 29, 30 and 21. The spool valve 24 is moved axially by turning the grip handle 34 to control the flow direction of the working fluid.

Abstract: A multilevel speed regulation jack includes an input oil cylinder, an output oil cylinder, and a fluid conduit member between the cylinders. The output oil cylinder includes a cylinder body containing an annular space and a tube piston, which fits in the annular space. A sliding sleeve of the tube piston is movably positioned in the annular space. An annular in-flow oil chamber is formed between the end annular surface of the tube piston and the cylinder body, and a central in-flow oil chamber is formed between the inner central surface of the piston and the cylinder body. The fluid conduit member includes at least two parallel fluid channels connected to the central in-flow oil chamber and the annular in-flow oil chamber, respectively. A control valve in one of the fluid channels opens/closes the channel. The jack can automatically switch between different jacking speeds based on the load sensed by the system and therefore has a high jacking efficiency.