Abstract: A hydraulic actuator assembly includes an actuator, a first sink subsystem in fluid communication with an upper working chamber of the actuator, a second sink subsystem in fluid communication with a lower working chamber of the actuator and a source subsystem in fluid communication with both the upper and lower working chambers of the actuator. A low pressure accumulator is in fluid communication with the upper and lower working chambers, the first and second sink subsystems and source subsystem. A high pressure accumulator is in fluid communication with the first and second sink subsystems and the source subsystem. The hydraulic actuator assembly can generate passive or active forces with or without energy recuperation.

Abstract: A device for controlling an underwater actuator by using an ambient pressure potential at the operating depth may include a chamber including a first cavity, a second cavity and a third cavity; the first cavity including a gas at a first pressure including one of at surface atmospheric pressure, lower than surface atmospheric pressure, or a vacuum; the second cavity including a first fluid at a second pressure including at least one of at underwater ambient pressure or higher then underwater ambient pressure and being connected to a underwater fluid supply; the third cavity including a second fluid at a third pressure including at least one of underwater ambient pressure or higher than the underwater ambient pressure and being connected to the actuator.

Abstract: In a method of controlling an injection molding machine M which controls specified operational processes in a molding cycle by variably controlling the rotation speed of a driving motor 3 in a hydraulic pump 2 and driving a specified hydraulic actuators 4a, 4b, . . . , in lowering the pressure Pd of the operational process to a specified pressure Pn, the pressure Pd is forcibly lowered by controlling the driving motor 3 in reverse rotation.

Abstract: On a protrusion-formation portion of a rod guide, there are provided a first annular protrusion for supporting a radially outer side of a lid body and a second annular protrusion for supporting a radially inner side of the lid body. Accordingly, when an upper end side of an outer cylinder is caulked, the first annular protrusion provided to the rod guide is allowed to sandwich and fix the radially outer side of the lid body between the first annular protrusion and the caulked portion. Further, although the lid body is strongly pressed to the rod guide with use of a presser at the time of caulking the upper end side of the outer cylinder, a pressing force acting onto the lid body can be received by the second annular protrusion. As a result, the lid body is prevented from being permanently deformed. With this structure, the lid body can be formed to have a small thickness dimension.

Abstract: A hydraulic actuator system designed to inwardly contain major portions of its control system. The system includes a unique non-vented and air tight sealed reservoir with expandable bladder. This inward control system and non-vented reservoir optimize space saving advantages and eliminate the need for external elements typically used in a hydraulic system, while extending fluid life, reducing cavitation and fluid oxidation, and increasing performance in the hydraulic system. The system configurations can work for both a single or dual acting linear actuator and further can involve a motor, hydraulic pump, and electro-hydraulic valve circuit used to control fluid throughout the system.

Abstract: In a hydraulic lift structure formed by arranging a hydraulic cylinder case internally provided with a hydraulic cylinder for moving up and down a working machine (a rotary power tiller) in an upper portion of a transmission case of a working vehicle, an oil reservoir of a working fluid for the hydraulic cylinder is provided in a boundary portion between the transmission case and the hydraulic cylinder case in such a manner as to be isolated from an inner portion of the transmission case. The hydraulic lift structure which prevents a malfunction of a hydraulic cylinder or the like and improves a supplying and discharging efficiency of a working fluid.

Abstract: A single acting hydraulic cylinder apparatus includes a mechanism operated by a single acting hydraulic cylinder, the mechanism including a hollow member. A breathing chamber is provided by sealing at least a portion of the hollow member such that outside air is prevented from entering the breathing chamber. A pressurized port of the hydraulic cylinder is adapted for connection to a pressurized hydraulic fluid source, and an un-pressurized breathing port of the hydraulic cylinder is connected to the breathing chamber such that air can flow between the breathing port and the breathing chamber.

Abstract: A master cylinder according to the invention has a predetermined number of second axial grooves formed on an outer peripheral surface of a tip portion of a secondary piston at predetermined intervals apart in a circumferential direction. Second radial holes are formed at the rear ends of some of the second axial grooves penetrate between the inner and outer peripheral surfaces of the piston. In an inoperative state, the rear ends of the second axial grooves and the second radial holes are all located to the rear of a seal point of a second cup seal, and a second fluid supply chamber is connected to a second hydraulic pressure chamber via the second axial grooves and the second radial holes. When the rear ends of the second axial grooves and the second radial holes are all moved in front of the seal point, the second fluid supply chamber is disconnected from the second hydraulic pressure chamber.

Abstract: A reservoir apparatus for a bicycle brake lever device comprises a master cylinder and a fluid reservoir including first and second reservoirs. The master cylinder has a master cylinder chamber dimensioned for receiving a master cylinder piston therein. The first reservoir has a first reservoir chamber in fluid communication with the master cylinder chamber for supplying a hydraulic fluid to the master cylinder chamber. At least a portion of the first reservoir chamber is disposed below a portion of the master cylinder chamber. The second reservoir has a second reservoir chamber in fluid communication with the first reservoir chamber, wherein the second reservoir chamber includes an air entrainment surface. The air entrainment surface is positioned higher than an upper surface of the first reservoir chamber.

Abstract: The present invention is an improved reservoir cap for a braking fluid reservoir including a cylindrical skirt for surrounding an opening of the reservoir body, a disc portion having a hard stop formed unitarily with the cylindrical skirt for closing the reservoir fill opening, and a plurality of teeth formed unitarily about the hard stop for securing an elastic member. The elastic member is disposed about the teeth of the reservoir cap and secured thereto. The elastic member defines ridges disposed circumferentially about its center. Between the ridges and the center of the elastic member is a channel, which in turn defines a pair of openings which permit the flow of excess fluid through the elastic member, thereby reducing the possibility of fluid overflow, and thus preventing excess brake fluid from permeating the reservoir cap and leaking into the engine compartment of a vehicle.

Abstract: A pressure medium cylinder with a piston rod (1) extending out on one side has a cylinder floor (3), which closes off the cylinder tube (2) on the piston side with a fastening element (4), and a function block (5), placed upon the former, with function elements (6 to 9). In order to improve the connection between cylinder floor (3) and function block (5), the cylinder floor (3) has at least one cylindrical outer connection area (17) into which the pressure medium lines (19, 20) that lead to the work chambers (11, 18) open to the outside and onto which the function block (5) is placed and attached with a sealed through-hole (21), into which the pressure medium lines of the function elements (5 to 9) open.

Abstract: Radial pressure is applied to a turbine generator armature bar using a simple hand held device that can be readily manipulated by a single human operator. A retainer platform has two wedge shaped portions with handles, and by the operator sliding the wedge shaped portions with respect to each other the operative width of the platform may be adjusted, including to slide and lock the platform in a conventional dovetail slot in a stator. An inflatable bladder is positioned on or mounted to the top surface of the platform and is dimensioned so as to apply radial pressure (for example through a filler) to armature bars mounted in the stator. A conduit, preferably having a valve with quick-release actuator in it, extends from the inflatable bladder and connects to a source of gas under pressure.

Abstract: To provide a hydraulic master cylinder with inlet ports and outlet ports arranged in an angle to each other wherein the outlet ports can be on either side of the housing without the need of two different casts, the master cylinder according to the invention is equipped with either two sets of protrusions adapted to be machined into inlet ports or two sets of protrusions adapted to be machined into outlet ports. The two sets of identical protrusions are arranged symmetrically with respect to the one set of different protrusions. Thus, depending on the desired side of the outlet ports, only one set of the two sets of identical protrusions is machined while the other set remains an unmachined accumulation of material.

Abstract: It is intended to dispense with the pipe welding work, thereby improve the pipe mounting performance and prevent contamination which results from welding, and elimination the waste of oil.A spigot portion 34 is mounted upright integrally in the center of the upper end portion of a piston 17, the base end of a piston rod 18 is fitted on the outer periphery of the spigot portion 34, and the outer periphery of the base end of a pipe 41 is press-fitted into an upper hollow part of the spigot portion 34.

Abstract: A gas spring element or gas cylinder element, particularly suitable for presses for non-cutting forming, including a closed non-compressible fluid system which includes the ring space between the piston or as the case may be piston rod and the cylinder or as the case may be cylinder head, wherein manipulation of the flow of fluid, which results from displacement movement of the piston, is used to hold the piston in the extended position and also to initiate release the piston rod, optionally including rate of return of the piston. Therewith there is achieved a complete timewise decoupling of the return stroke movement of a press ram and a piston rod.

Abstract: A plastic reservoir adapted for use with a hydraulic power pack. The reservoir includes a plastic body and a substantially plastic mounting ring which is joined to the plastic body of the reservoir. The mounting ring includes a metal reinforcing ring which is encapsulated in the plastic portion of the mounting ring.

Abstract: An electro-hydraulic actuator having an electric motor disposed in a hydraulic fluid reservoir and connected to drive a hydraulic fluid pump. The actuator includes a piston rod which extends or retracts as a piston is hydraulically driven in a cylinder. An actuator housing forms the reservoir and cylinder and contains hydraulic passages connecting the pump, reservoir and cylinder. The actuator includes a one-way filter for filtering the hydraulic fluid. The hydraulic pump is preferably a rotating piston type and includes a port plate which allows the pump to drive the piston while the retract and extend chambers of the pump have different or unbalanced fluid drive ratios. A load limiting valve protects the system from excessive hydraulic pressure and a position sensor detects the position of the piston rod.

Abstract: A high-performance, robust gas-compression device of long-term reliability is adapted in particular for storing nitrogen gas under compression, and includes a substantially cylindrical body (1), a piston (4) partially projecting into the gas-storage chamber (2), upper (7) and lower (6) piston guiding sleeves surrounding the piston, a lubrication chamber (9) formed in one of the guiding sleeves, adapted for holding a lubrication fluid for lubricating the guiding sleeves, and respective annular sealing joints (14, 19) which are accomodated in the guiding sleeves. One annular sealing joint is formed with an annular groove in communication with the principal gas-storage chamber, thereby exposing that sealing joint to a pressure prevailing in the principal gas-storage chamber; the other sealing joint is exposed to a constant pressure from the lubricating fluid.

Abstract: A double-cylinder construction which can be used not only in large-sized compression molding machines but also in small-sized or medium-sized compression molding machines. In the double-cylinder construction of the present invention, a ram slidably fitted within an outer cylinder is provided in the center thereof with a hollow part. A rod slidably fitted in said hollow part is fixed to the bottom of said outer cylinder without penetrating said bottom thereof, and said rod does not contain an oil passage within. The double-cylinder construction always contains a certain amount of oil within and this self-contained oil is moved back and forth within the double-cylinder construction when the ram is being moved up and down. Therefore, the amount of oil supplied to the double-cylinder construction from outside is very small.

Abstract: A rod seal for a linear hydraulic or pneumatic actuator cylinder includes a seal ring that has a bore that closely matches the diameter of the rods, proximal and distal cylindrical portions and a central annular flange. A seat in the actuator cylinder distal end assembly has proximal and distal cylindrical portions and a central void to receive the rod seal ring proximal and distal portions and central flange respectively. A radial clearance is provided so that the rod seal ring can travel radially, at least for a limited distance, while the rod passes axially through it. Static elastomeric ring seals are provided in the proximal, distal and central portions, and define pressure balancing regions. The rod seal assembly can be constructed at low cost, yet achieve a high degree of sealing with low axial friction characteristics.

Abstract: A volumetric apparatus for portioning fluidic material into fractions of predetermined size includes a housing having an inlet and an outlet, and a piston movable in the housing and defining a product portioning chamber and a compression chamber. Fluidic material is fed into the product portioning chamber through the inlet under pressure when the inlet is open and the outlet is closed, the pressurized fluidic material forcing the piston from a first position by a preset distance such that a predetermined volume of the fluidic material is fed into the product portioning chamber. Thereafter, the piston is driven from the second position to the first position when the inlet is closed and the outlet is open so as to deliver the portioned fluidic material from the product portioning chamber through the outlet.

Abstract: A master cylinder assembly especially adapted for mounting in the passenger compartment of a motor vehicle in association with the clutch pedal assembly of the motor vehicle. The unit is permanently sealed and is non-serviceable so that no fluid leakage occurs in the passenger compartment as a result of attempts to service the unit. The master cylinder assembly includes a cylinder having an open rearward end and a closed forward end, an external mounting flange intermediate the ends, and an elongated reservoir mounted in piggyback fashion on the cylinder between the mounting flange and the forward end of the cylinder with the rear end of the reservoir pivotally secured to the mounting flange and with a discharge fitting on the forward end of the reservoir moving into telescopic sealing relation with a reservoir fitting on the forward end of the cylinder in response to pivotal movement of the rear end of the cylinder about the pivot axis defined between the rear end of the reservoir and the mounting flange.

Abstract: A hydraulic master cylinder assembly of the type including a reservoir in which a diaphragm is disposed to divide the reservoir chamber into a hydraulic fluid chamber outside of the diaphragm and in communication with the pressure chamber of the master cylinder and a gas chamber within the diaphragm. The diaphragm is generally tubular with an open end and a closed end, and in a cross section transverse to the central axis of the diaphragm, includes a plurality of radially extending arms arranged about the central axis of the diaphragm and each including a pair of side walls defining therebetween a portion of the volume of the gas chamber. The diaphragm is movable between an expanded condition in which it assumes a substantially circular configuration in cross section and a collapsed condition in which each of the pairs of side walls of the arms are collapsed with respect to each other to reduce the volume of the chamber.

Abstract: A fabricated master cylinder having a reservoir part and in interlocked cylinder part defining a cylinder bore and which a slidable piston is supported. The reservoir part that extends into the cylinder bore defines a shoulder that cooperates with a recuperation valve for forming an actuating stop for holding the makeup fluid recuperation valve in an opened position when the piston is at its at rest position.

Abstract: A stroke variable device comprising a large diameter cylinder and a small diameter cylinder which are interconnected to each other. A large diameter piston and a small diameter piston are slidably inserted into the large diameter cylinder and the small diameter cylinder, respectively, and a cylinder chamber is formed between the inner end of the large diameter piston and the inner end of the small diameter piston. A first seal member is arranged to surround the projecting outer end of the large diameter piston, and a second seal member is arranged to surround the projecting outer end of the small diameter piston. One end of the first seal member is fixed to the projecting outer end of the large diameter piston, and the other end thereof is fixed to the housing of the device to form a first hermetically sealed chamber therein.

Abstract: A self-lubricating die cylinder assembly is provided containing a cylinder, piston, expansion reservoir and working chamber. A lubricating oil recirculation means is provided to transport oil between the working chamber and the expansion reservoir during each of the piston strokes. A flow restrictor is provided to create a pressure differential between the two chambers during movement of the piston thus creating a jet mixture of compressible working fluid and lubricating oil spraying onto the walls of the cylinder.

Abstract: An oscillator is proposed which comprises a pair of cylinders having a common, circular-cylindrical outer wall (100) and two sealingly guided pistons (120, 122) each having one piston rod (121, 123), which are likewise guided in a sealing manner to the outside through the closure walls of the cylinder. The cylinder is divided by the pistons (120, 122) into outer chambers (124, 125) and inner chambers combined into one common chamber (126). The chamber (126) is filled with fluid. The outer chambers (124, 125) have two openings (102, 103) offset from one another by 180.degree.. A control cylinder (101) having axially offset, oppositely disposed holes (104, 105, 106, 107) connects the outer chambers in alternation with an annular high-pressure chamber (113, 115) and an equalization chamber (114) whenever the control cylinder (101) is rotated. The two pistons (120, 122) thereby execute movements in common toward the left or right, respectively.

Abstract: A door closer comprising at the end of one of two pivotally interconnected arms a closing device whose housing encloses a cylindrical piston driven by the arm through a rack-and-pinion system. On each side of this piston a return spring and a bag, filled with an incompressible but deformable viscous gum placed in a hollow piston biased elastically toward the cylindrical piston are placed on each side of the first-mentioned piston. The hollow piston has a diameter distinctly larger than the diameter of the first-mentioned piston, and the combined actions of this difference in diameters and of the viscosity of the gum ensure an effective braking of the return of the first-mentioned piston.

Abstract: A hydraulic brake booster provides a housing within which a spool valve is slidably mounted. The housing forms a pressure chamber and the spool valve is movable from a first position venting the pressure chamber to a second position, communicating the pressure chamber to a fluid pressure source as the spool valve moves toward the second position. A piston or cylindrical accumulator is also slidably mounted in the housing and moves in response to pressurized fluid in the pressure chamber to actuate braking. In order to hydraulically actuate braking when the pressure source is disabled, the piston includes a storage chamber within which pressurized fluid from the pressure chamber is stored. With the source disabled an operator actuating means moves the spool valve to the second position to close the pressure chamber to the pressure source.

Abstract: Primary switches in bus cab, for instance, activate contacts in secondary switch group in rear transmission compartment to energize solenoids selectively pressurizing opposed cylinders to drive transmission shift operation to various positions.

Abstract: An expanding chamber hydraulic motor venting through a working member reduces the motor/stroke-limiting venting valve assembly to three simple components: a cup-shaped cylinder, an annular gasket at the open end of the cylinder, and undersize piston sufficiently loose in the cylinder to provide free-flow of hydraulic fluid therebetween but protruding through the gasket in a sealing fit; in operation, fluid pressure introduced by conventional means between the piston and cylinder can force the piston to extend from the cylinder only within a maximum stroke length limited by an annular groove around the piston which when it reaches the gasket vents the pressure past the gasket.

Abstract: A hammer and more particularly a fluid operable hammer wherein alternating impetus provided by pressurized liquid and gas means actuates a reciprocable hammer piston to generate repetitive impact loads.

Abstract: A laser formed hole is used as a "weep" hole in a hydraulic jack to limit the power stroke of the ram thereby permitting the use of a urethane packing on the ram instead of the usual leather packing.