Abstract: Hydraulic booster device intended to be arranged in parallel with a primary actuation circuit between an actuator mechanism and a receiver, the device comprising an electromagnetic valve mechanism (10) arranged between an actuator (12) and a pressure-fluid source (16), the actuator (12) comprising a piston means (56, 66, 92) displaceable under the effect of the pressure-fluid and intended to actuate the receiver independently in response to an electrical control signal supplied to the valve mechanism (10).

Abstract: This invention pertains to a pneumatic mode under which the structure of a hydraulic system is driven, particularly denoting the pneumatic mode under which a mini air compressor is being used as a means to elevate a hydraulic jack.This invention makes use of a working lever and a working body attached to the hydraulic mechanism which is compactly closed inside a body to drive the hydraulic lever of the hydraulic mechanism which is compactly closed at the other end of the body to conduct a continuous backward/forward movement which will press against and elevate the hydraulic jack. Such a movement is similar to a continuous backward/forward movement conducted by a piston in a cylinder body. However, the entire structure and effected of this invention is found much better because of its easy fabrication and its function of elevating the hydraulic jack by means of a pneumatic mode, which saves both time and strength and thus meet the requirement of a simple and automatic operation.

Abstract: This invention relates to a mechanism and a process by which hydraulic pressure principles may be applied to any reciprocating or rotational means, for instance a piston or a motor, to make the energy output thereof more efficient per unit of energy input into these machines. The unitary hydraulic unit comprises a first larger reservoir cylinder and a second smaller reservoir cylinder which is fluidly connected to the first larger cylinder. Energy is input onto the force receiving surface of the first larger reservoir cylinder and force is hydraulically transferred from the first larger hydraulic cylinder to the force transferring surface of the second smaller hydraulic reservoir. In a preferred embodiment, this two-reservoir system can be applied to any machine with a rotational output by means of a disclosed power conversion means. An efficient power takeoff means for converting reciprocal energy into rotational energy for use in connection wiht the unitary hydraulic unit is also disclosed.

Abstract: Hydraulic pressure transducer having an operating cylinder (10) with an operating piston (12) and operating piston rod (14) adapted for rapid traverse, and a transducer piston (22) and piston rod (24) guided within an axially connected power cylinder (20). The transducer piston rod (24) is of a smaller diameter than the operating piston rod (14) and is capable of plunging into the operating cylinder volume (16), the transducer piston rod (24) extending through a seal (58) separating said operating cylinder volume (16) from the power cylinder.

Abstract: A hydraulic accumulator for subsea use, which charges itself as it is lowered to the operating depth. The seawater and hydraulic fluid operate against unbalanced pistons (36, 52) with low pressure gas (42) therebetween.

Abstract: In a hydraulic double-acting hydropneumatic pressure multiplying device suited for generating hydraulic pressure, and comprising a cylinder within which a piston is slidably mounted. The multiplying device is capable of generating hydraulic pressure in both the backward and forward strokes of the piston within the cylinder. For this purpose, the cylinder is closed at the bottom by a lower cap having an upwardly extending plunger received within a portion extending upwardly from the piston. The cylinder also provides an upper cap with a dome and the upwardly extending portion of the piston is reciprocating within this dome, thus defining between the portion of the piston and the dome a first pressure generating chamber, and within the upwardly extending portion of the piston and the plunger of the lower cap a second pressure generating chamber for obtaining hydraulic pressure in both of the strokes of the piston.

Abstract: A pneumatic-hydraulic booster for vehicle includes a master cylinder part; a pneumatic cylinder part combined with the master cylinder part which includes a power piston slidable fitted to a cylindrical casing and an output rod fixed to the power piston, extending to the master cylinder part; a partition wall body fitted to the cylindrical casing; and a relay valve part arranged at the opposite side of the partition wall body from the power piston in the cylindrical casing. The relay valve supplies compressed air into an air pressure chamber formed between the partition wall body and the power piston and discharges the compressed air from the air pressure chamber to the atmosphere. When compressed air is suppplied into the air pressure chamber through the relay valve part the power piston and the output rod are moved forwards to generate hydraulic pressure in the master cylinder. The hydraulic pressure is applied to a wheel cylinder for braking.

Abstract: A pneumatic-hydraulic booster for vehicles includes a master cylinder part; a pneumatic cylinder part combined with the master cylinder part including a power piston slidably fitted to a cylindrical casing and an output rod fixed to the power piston, extending to the master cylinder part; a partition wall body fitted to the cylindrical casing; and a relay valve part being arranged at the opposite side of the partition wall body to the power piston in the cylindrical casing. The relay valve supplies compressed air into an air pressure chamber formed between the partition wall body and the power piston and discharges the compressed air from the air pressure chamber to the atmosphere. When compressed air is supplied into the air pressure chamber through the relay valve part, the power piston and the output rod are moved forwards to generate hydraulic pressure in the master cylinder part. The hydraulic pressure is applied to a wheel cylinder.

Abstract: A floating plate is provided in a cylinder chamber and slides freely like a piston. A first group of laminated, ring-shaped, thin-plate piezoelectric elements is provided between a fixed support member provided on part of a wall portion of this cylinder chamber and the floating plate. A second group of laminated, cylindrical, thin-plate piezoelectric elements is provided in the center of the first group and a working member is provided on the free end of the second group of elements that is not attached to the floating plate. A hydraulic chamber is formed in the cylinder chamber on the side of the floating plate opposite to the side on which the first and second groups of elements are provided, and the pressure in this hydraulic chamber pushes the floating plate in the direction of the fixed support member.

Abstract: A hydraulic brake system comprising a pedal-operated brake booster (5), which is connected with the master cylinder (3) and includes an auxiliary pressure supply system (13), a booster piston (4), and a booster chamber (7) wherein an auxiliary pressure is established which is proportional to the foot pressure (F). The hydraulic brake system is provided with wheel brakes (14,15,16,17) connected to the master cylinder (3), a filling stage cylinder (18) is provided which displaceably houses a two-stage piston (20). A pressure chamber (21) is arranged in front of the large stage (83) of the two-stage piston (20) and a filling chamber (22) is arranged in front of the small stage (84) of the two-stage piston (20). In this arrangement, the filling chamber (22) communicates with one of the working chambers (26) of the master cylinder (3) and/or a brake line (28) by way of a pressure line (25).

Abstract: A numerically controlled lathe has its tailstock body clamped on ways of a bed at a desired position by pucks through using an intensifier to increase the hydraulic pressure applied to the pucks to three times the hydraulic source pressure. The intensifier is automatically replenished with hydraulic fluid each time that there is release of the clamping pucks.

Abstract: A double admitting pressure intensifier which automatically reverses at its end positions is provided. The pressure intensifier comprises a pressure intensifier piston and a control slider running parallel to the pressure intensifier piston, each disposed in a bore of a casing. The control slider receives a control impulse only at the end of a stroke in order to maintain the pressure intensifier trouble-free under all conditions. This is assured by disposing two pressure pins of different diameter projection into axial bores of the control slider. The pressure pin with the larger diameter is connected to the feed line or, respectively, to the discharge port depending on the position of the pressure intensifier piston. The pressure pin with the smaller diameter is, on the other hand, continuously connected with the feed line.

Abstract: An actuation installation for use under extreme environmental conditions, such as freezing, uses a two-fluid system in which one fluid is impervious to the extreme environment, and the other fluid, such as water, is not. A two-chamber accumulator-separator has a water chamber connected to a water source via control valves and a working fluid chamber connected to a hydraulic actuator port. The other actuator port is connected to a working fluid chamber of a two-chamber accumulator having a sealed air-pressure chamber. When water is admitted to the water chamber, the actuator will move in a first direction further compressing the air in the air pressure chamber. When the water is drained from the water chamber, the accumulator air-pressure moves the actuator in the opposite direction. The actuator is positioned in the extreme environment, with the remainder of the system installed in a protected environment such as underground.

Abstract: A dual-piston hydraulic brake master cylinder includes a large hydraulic piston which supplies an initial large brake fluid volume and a small hydraulic piston which continues to supply brake fluid to the brakes when the large piston stops moving forward in its cylinder at higher brake pressures. The small, central hydraulic piston is connected to the end of a piston rod extension of a pneumatic booster piston. The large piston surrounds the small piston and opens a reservoir line tilt-valve in the piston retracted position. A passageway between the large and small hydraulic chambers is open in the retracted position to allow communication of braking fluid therebetween. During brake actuation a seal arrangement interrupts this communication. The large and small hydraulic chambers supply the brake circuits through delivery passages.

Abstract: An impact power tool for delicate hand working operations is provided which is especially adapted for detailed engraving, carving, and delicate stone setting applications. The power tool preferably includes a hand-held impact device, a piston received within the body of the device and shiftable therein for delivering impact energy to the device, conduit for delivering and venting motive fluid from and to the hand-held device for shifting of the piston, and a valve coupling the directing and venting conduits to the device in alternative fashion at rapid, variable, cyclical rate. The impact tool may be operated by connection to a standard source of pressurized air. The tool is capable of providing a greater range of impact strokes per second than conventional hand-held controlled impact tools, and thereby provides expanded capability for extremely delicate and fine engraving, carving and stone setting work.

Abstract: A thermally powered engine has a pair of power cylinders with each power cylinder defining a closed interior space. A power pistin is reciprocally mounted in the interior space of each power cylinder with each piston dividing the interior of its cylinder into upper and lower portions. A liquid piston interconnects the upper portions of the two power cylinders. First mechanically powered valves having two states control the flow of the working fluid of a heat transfer loop through the lower portions of each power cylinder. A second mechanically powered valve causes the first mechanically powered valve to change state so that movement of the power pistons in the pair of power cylinders is substantially 180.degree. out of phase.

Abstract: A hydraulic vehicle brake system of the type having a high system return pressure is provided. In order to minimize the size and strength of brake return springs required, the invention provides a device to be interposed between the brake and the brake control valve. Preferred embodiments of the device include an inlet port communicating with a brake valve and an outlet port communicating fluid pressure to a vehicle brake. A control assembly is provided intermediate the inlet and outlet ports and includes mechanisms for amplifying the hydraulic pressure effect in the direction from the outlet port to the return pressure system so that the brake return pressure exerted by the brake return springs can be substantially less than the hydraulic system return pressure.

Abstract: A percussive tool comprises a percussion mechanism and a pressure pulser. The percussion mechanism has a hollow housing with a piston hammer arranged thereinside to form two chambers of variable volume. The pressure pulser has a hollow housing and a fluid displacer defining inside the housing a working chamber adapted to alternately communicate with a source of gaseous fluid and the interior of the percussion mechanism. The fluid displacer is intended for forced displacement inside the housing to transmit to the chambers of the percussion mechanism a pulsed pressure of the gaseous fluid which causes the piston hammer to reciprocate. The interior of the percussion mechanism is isolated from the outside, whereas the working chamber of the pressure pulser communicates with at least one of the chambers of the percussion mechanism, the chambers of the percussion mechanism continuously intercommunicating by way of a restrictor passage.

Abstract: A fluid power apparatus particularly useful for an industrial robot which includes a pair of expansible chamber devices each having a pair of control chambers in fluid communication with each other to intensify the working fluid output pressure and a working chamber that expands to receive a charge of working fluid and contracts to expel working fluid therefrom. A working fluid circuit includes a first line connected with one of the working chambers and a second line connected with the other of the working chambers. A fluid actuator is connected with the circuit and has a moveable element that moves in response to flow of working fluid in the circuit to the actuator. The apparatus has a static condition in which the one working chamber is contracted with the moveable element of the actuator stationary in a first position.

Abstract: A hydraulic volumetric proportioning valve which may be installed in pre-existing hydraulic systems such as aircraft landing gear extension and retraction systems to independently regulate and vary the rate of hydraulic system operation at desired stages of system operation in response to the volume of fluid flow through the system during each stage of system operation.

Abstract: Fluid actuation device with compensation for wear, particularly for friction clutch mechanisms of the type having a cylinder in which there are placed a first piston resting on a spring and a second piston extended by a declutching control rod, and in which the space between the pistons is filled with an incompressible fluid. The cylinder carries a separation wall between two compartments which house respectively the first and the second pistons. An orifice for communication between said compartments carried by the separation wall is associated with a stopper valve rigidly connected to a membrane that is subjected to a pressure for control and transmission of a thrust force on the cylinder and for driving the control rod.

Abstract: An intermediate actuating metal bellows filled with a liquid is positioned between an explosive gas cartridge and an actuating piston in an ordnance ejector system. The bellows is miniaturized, light weight and of low spring rate. The liquid in the bellows creates a fluid pressure internal to the bellows equal to the gas pressure external to the bellows, and is of low compressibility, low viscosity, low coefficient of thermal expansion, wide operating temperature range and high thermal conductivity. The fluid-filled bellows transmits gas pressure to the piston but prevents damage to the piston and piston seals from the high-pressure, high-temperature erosive gas. The liquid in the bellows acts as a heat sink to protect the bellows; as a heat insulator reducing heat losses to the piston housing and insulating the piston and piston seals from high temperature; and as a lubricant for the piston and piston seals. Environmental pressures and temperatures of 18,000 psi and 4500.degree. F.

Abstract: An articulated joint, for example in a robot arm, has a braking device which can brake movement in the joint when desired, so that forces transmitted across the joint are not transmitted through the mechanism which moves the arm. The braking device has an annular expandable, for example tubular, element which is positioned between concentric facing surfaces on either side of the joint, i.e. on the arm and on the part of the robot to which the arm is articulated. Hydraulic pressure can be applied to the expandable element to cause it to expand and lock together the concentric surfaces.

Abstract: A hydraulic cylinder device for power multiplication includes a cylinder (1) containing a single-stage piston (2) having a piston rod (4) and a two-stage secondary piston (3), the piston rod (4) extending through a bore in the secondary piston. The cylinder (1) is closed by a cylinder cover (16) through which the piston rod (4) also extends. Two stop-pistons (22, 24) with different strength springs (21, 23) are located in projection (20) integral with cylinder (1) and opposite the stop-pistons are two opening-pistons (33, 34).

Abstract: A thermally powered engine which obtains energy from a closed heat transfer loop. The engine has two power cylinders. A piston is reciprocally mounted within each cylinder and divides the interior space of each cylinder into two portions. A piston rod is affixed to each piston and extends through the upper closed end of each cylinder. A flexible diaphragm is mounted in the lower portion of each cylinder and with the lower closed end of the cylinder forms a power chamber. A fluid fills the upper portion of both cylinders. A passageway between the cylinders permits the fluid to act as a free piston causing the piston of the cylinder in its exhaust stroke to force refrigerant from its power chamber to the condenser of the heat transfer loop. Refrigerant from the evaporator of the transfer loop flowing into a power chamber forces the piston upward during the pistons power stroke. Valves regulate the flow of refrigerant into and out of the power chambers of each of the power cylinders.

Abstract: An improved pneumatic-hydraulic actuated single action pull type installation tool for installing pull type fasteners is disclosed which includes a continuously pressurized fluid reservoir operative to maintain a minimum positive pressure on the hydraulic circuit during operation so as to protect the integrity of the hydraulic circuit during normal operating pressure fluctuations and to reduce the possibility of air being drawn into the hydraulic system during sudden pressure drops in the actuating pressure chamber which may occur at the time the pintail portion is separated from the fastener. Further, the reservoir provides a source of make up hydraulic fluid to replace any fluid which may be lost due to leakage. Suitable valves are provided to enable the reservoir to selectively communicate with both driving and return portions of the hydraulic circuit while still enabling selective pressurization thereof.

Abstract: Combustible fuel gas at low or moderate pressure is supplied to an inlet in the top of an upright working cylinder. The working cylinder then is filled with liquid through a bottom liquid inlet to force the gas from the cylinder and direct it into a storage cylinder. A check valve prevents backflow of gas from the storage cylinder as the liquid is drained from the working cylinder and as the working cylinder again is filled with low or moderate pressure gas. The process of filling the working cylinder with liquid to force the gas from it into the storage cylinder and holding the gas in the storage cylinder while the liquid is drained and the working cylinder is refilled with gas is repeated until the gas in the storage cylinder is a desired high pressure, such as 1500 psi or higher. Two working cylinders can be provided so that, as one of them is drained, the other is filled with liquid, such that gas is substantially continuously forced into the storage cylinder until the desired high pressure is achieved.

Abstract: A brake control system in which the master cylinder has two pressurizing chambers for each brake circuit. Three brake circuits are disclosed in detail. One piston of each set of pressurizing chambers is directly applied by brake pedal force. The other piston of each set receives brake pedal force through resilient means, with additional force supplied by suitable servomotors. The servomotors are individually controlled to provide power-assist when appropriate, or to decrease the forces supplied by them to control wheel slip or wheel spin.

Abstract: A hydraulic system is disclosed which provides automatic proportional actuation of pairs of hydraulic cylinders. The proportioning mechanism comprises one or more standard hydraulic cylinders.

Abstract: The device comprises a hydraulic operating actuator (5), associated with a friction element (4) and capable of being operated by a liquid under pressure to bring the friction element into frictional contact with the component to be braked (2); and a pneumatic actuator means (10), incorporating a hydraulic chamber (20), joined to the hydraulic actuator (5), and a pneumatic chamber (14) capable of being joined to a source of gas under pressure, the two chambers being separated by a movable wall structure forming a piston, the hydraulic chamber (20) being at least partially defined by a flexible elastic envelope (21) arranged in the immediate vicinity of the hydraulic operating actuator.

Abstract: For use in a brake booster of the type having a master cylinder disposed rearwardly of a booster mechanism having a power piston and in which a braking reaction force produced on an output shaft is transmitted therefrom to an input shaft through a reaction disc and a reaction transmitting member, an apparatus is provided for adjusting the magnitude of a clearance defined between the reaction disc and the reaction transmitting member. In this apparatus, the input shaft comprises a first section associated with the reaction transmitting member and a second section on which a valve seat is formed. The valve seat forms a valve mechanism disposed within a valve body for controlling the opening or closing of a passage for hydraulic fluid. The first and the second section of the input shaft are formed by separate members, both of which project toward the front shell and are connected together in a manner to permit their relative position to be adjusted.

Abstract: A first pressure-intensifying apparatus includes a working cylinder having a working piston mounted within it and reciprocally movable by the application of working fluid alternately to opposite sides of the working piston. The working piston in turn drives a high-pressure piston movably mounted within a high-pressure cylinder. The flow of pressurized working fluid to the working cylinder is controlled by a control valve. The control valve receives pressurized fluid from a source of working fluid and directs the fluid to the working cylinder and then back to a working fluid reservoir or tank. The control valve includes a valve body and has a spool movably mounted therein that is movable between a first position in which fluid is directed to one side of the working piston and a second position in which fluid is directed to the other side of the working piston.

Abstract: An improved pneumatic-hydraulic driving device for the knockout mechanism associated with the slide of a press-machine wherein the device serves to actuate the knockout mechanism in a controlled manner to provide cushioning motion during punching of the work, and knocking out motion after punching to permit removal of the punched work by a transfer machine, with the device being particularly useful in the fabrication of printed circuit plates wherein the device serves to decrease cycle-time of fabrication and increase quantity of production.

Abstract: The invention relates to an intensifier using liquid, comprising at least one cylinder which has plural pistons and a lubricating chamber between them.

Abstract: The invention relates to a pneumatically controlled pressure transducer for operating hydraulic work tools having a dual operating cylinder, on one side of which a pneumatically operable piston, on the other side a hydraulically operable piston is provided and, to the hydraulic side of which a hydraulically operable working tool can be joined.The essence of the invention resides in that a control valve is provided which is coupled with the primary space located in front of the piston of the pneumatically operable cylinder of the operating cylinder and, which is connected into an operating relationship with a starting valve, and wherein the control valve is connected over a throttle-check valve to a further valve on one side, while on the other side, over a quick exhaust valve, is connected with a hydraulic container, respectively, over a valve with the secondary space of the pneumatically operable cylinder.

Abstract: An applied pressure or volume change is intrinsically transformed into an output pressure or volume change which is related to the magnitude of the relative input quantity and a ratio of effective areas of pressure application surfaces of a plurality of pistons in a fluidic transformer. The surfaces of the pistons are interconnected by fluid communication paths in a predetermined manner such that pressures existing in each of the communication paths relate only to the input pressure relative to the reference pressure and a ratio of the effective surface areas of the pistons, and such that the pistons are in a balanced force equilibrium state. The pressures present in the communication paths can be operatively applied on opposite sides of fluid sealing elements of a plurality of sealing elements arranged in serial order to operatively seal between the applied pressure and the reference pressure.

Abstract: This mechanism makes it possible to obtain in succession a fast approach stroke (C), and then a work stroke with a substantial developed stress, in operations such as riveting or marking, the work stroke being started as the tool (16) comes into contact with the part to be pressed (25). A control stem (4) and a body (9) are movable along one and the same axis (3), means such as a clack (31) providing for their non permanent locking. The stem (4) is integral with a primary piston (8) penetrating into a hydraulic circuit (10, 11) of the body (9); this circuit communicates, on the one hand, with an expansible casing (19) surrounding the body (9) and making it possible to block this body with respect to the frame (1), and on the other hand, with a chamber (12) in which a secondary piston (15), drawn back by a spring (18) and integral with tool (16), slides.

Abstract: A combination air brake cylinder and hydraulic slack adjuster for a railroad car brake system includes an air operated piston positioned within a housing. There is an air port in the housing in communication with the air piston and there is a return spring in the housing operable upon the air piston. The housing includes a fluid outlet port and a fluid piston and valve arrangement within the housing connected to the air piston and responsive to brake application movement thereof to supply a brake shoe application fluid pressure at said outlet. A fluid reservoir is associated wtih the fluid piston and valve arrangement and has check valve controlled connecting passages thereto for adjusting slack in the brake rigging during brake application functions.

Abstract: An oscillating coolant pump includes a pair of opposed bellows mounted to reciprocate in a housing for moving a volume of fluid through a heat exchanger and an electronics package. The pump functions without the use of check valves.

Abstract: A control system for a superhigh pressure generation circuit includes a hydraulic pump having a usual range of delivery pressure. An electrohydraulic servo valve controls the flow rate of pressurized fluid from the pump and supplies it to a primary side of a boost cylinder. A stepped piston slidably received in the boost cylinder strokes in response to the input fluid to generate a fluid pressure elevated in accordance with an effective sectional area ratio of the stepped piston in a secondary side of the boost cylinder. The fluid pressure in the secondary side is caused to coincide accurately with a reference pressure level on the basis of a feedback control.

Abstract: A hydro-pneumatic actuator for providing a two-stage buildup of the hydraulic output pressure. A primary hydraulic piston, to which a pneumatic input piston actuator is connected, acts in a larger bore of a hydraulic cylinder to transfer fluid via a central passage in a spring-loaded, differential area, secondary hydraulic piston, that is coaxially disposed in the hydraulic cylinder in spaced-apart relationship with, and downstream of, the primary piston. A larger face of the secondary piston is in the larger bore and the smaller face is in a reduced diameter bore of the hydraulic cylinder, so that a pressure buildup in the hydraulic cylinder effects actuation of the secondary piston to close a check valve and thereby inter-fluid communication between the larger and smaller bores of the hydraulic cylinder via the central passage.

Abstract: In an apparatus for forming leak-proof joints between tubes and a tube sheet by the internal application of hydraulic swaging pressure, the flow of relatively low pressure fluid from a pressure source to an intensifier is permitted or interrupted by a control valve. During a prefill period, a prefill valve causes the low pressure fluid to bypass the low pressure input side of the intensifier and flow directly to the high pressure side and then to a mandrel. Thereafter, the low pressure fluid is caused to enter the low pressure side of the intensifier to increase the pressure in the mandrel during a swaging period. A pressurization sensor, which is connected to the input and output sides of the prefill valve, contains a piston which is movable in response to the difference in the pressures at these two points to produce a termination signal which, after a delay, actuates the control signal at the end of the swaging period.

Abstract: A two-stage, hydro-pneumatic actuator suitable for use as a railway vehicle brake. The hydraulic cylinder comprises a large diameter bore in which a low- and a high-pressure piston operate jointly during a first stage of operation to effect a high volumetric displacement of hydraulic fluid via a small diameter bore in order to take up the clearance between the brake shoes and wheel. As the brake shoes contact the wheel, the high-pressure piston enters the small bore to interrupt further displacement of hydraulic fluid from the large bore. The force of the high-pressure piston alone during this second stage of operation produces the required brake forces with a high multiplication factor. Make-up fluid is drawn into a chamber on the backside of the low-pressure piston during a brake application stroke an amount corresponding to the over-travel of the high-pressure piston and is subsequently discharged into the hydraulic cylinder during retraction of the brakes to compensate for brake shoe wear.

Abstract: An improved rephasing master cylinder in which the cylinder wall approximate the end of the cylinder has a longitudinal bleed passage in the cylinder wall at one end connected to a lateral passage opening into the forward cylinder chamber while the opposite end of the longitudinal passage connects with the rearward chamber of the cylinder when the cylinder piston is located therebetween. This longitudinal bleed passage permits the restricted flow past the master cylinder piston when the piston is nearing and at the end of its stroke, thereby causing both master and slave pistons to complete their respective strokes.

Abstract: A maximum displacement, reciprocating air operated demand only hydraulic power unit for supplying hydraulic fluid under pressure to one or more hydraulic motors, comprising a pneumatic power cylinder having a power piston therein, a hydraulic slave cylinder having a slave piston therein powered by said power piston, said slave cylinder being connected to each said hydraulic motor to power same, a valve mechanism for controlling the supply of air and oil to said power and slave cylinders, a mechanism to control the valve mechanism to operate the unit in a steady reciprocating motion, and an intensifier for two stage operation of said motors in either operating direction of the unit. An accumulator may also be included to supply fluid when the unit changes direction.

Abstract: A method and apparatus for simultaneously adjusting the fluid pressures in a dual hydraulic circuit arrangement in which in a first hydraulic circuit pressurized fluid is supplied from a first pressure source to a first fluid pressure activated device and in a second hydraulic circuit pressurized fluid is supplied from a second pressure source to a second pressure activated device, comprising a cylinder having opposite closed ends and spaced bulkheads therein defining a central chamber between the bulkheads and a pair of chambers on respective opposite sides of the bulkheads. A pair of spaced first pistons are slidably mounted in the central chamber to define a control pressure chamber therebetween and first and second primary fluid pressure chambers between respective pistons and the bulkheads. The first primary fluid pressure chamber is connected to the first pressure source while the second primary fluid chamber is connected to the second pressure source.

Abstract: In a pneumatic-hydraulic system for driving a hydraulic actuator, a single pneumatic-hydraulic converter includes a cylinder casing with inlet and outlet ports and a plunger reciprocably disposed within the casing to form a hydraulic chamber in open communication with the inlet and outlet ports and a pneumatic chamber for connection to a pneumatic pressure source, the hydraulic chamber having a displacement capacity filled with a predetermined amount of hydraulic fluid necessary for producing at least one reciprocating motion of the actuator.

Abstract: A hydraulic actuating and locking device includes a locking piston within a cylinder, an actuating piston within a cylinder in the rear surface of the locking piston and a pressure multiplier connected to the space behind the piston. A passage, constituting a high pressure cylinder, connects the space behind the piston to an oil reservoir and is adapted to receive and be sealed by the high pressure piston of the pressure multiplier.

Abstract: A toggle assembly for vehicles or cars comprising a relay cylinder mounted on an end plate including a booster cylinder and an output cylinder, a control chamber arranged in coaxial relation to the relay cylinder, a control valve for controlling a gas by a hydraulic pressure of a master cylinder, said valve being arranged in operable association with the control chamber, and a booster piston disposed in the booster cylinder and in operable association with the controlled gas, wherein said end plate is provided with a shell for said booster cylinder as an integral piece, said shell is integrally provided with a first compressed air passage having its one end being open in the back chamber of the booster cylinder for the booster piston and its other end passing through said end plate and being open at the end of a relay valve body, and a second compressed air passage is provided to extend from a casing for said control chamber, said second passage having its one end in communication with the other open end of s

Abstract: In an apparatus for forming leak-proof joints between tubes and a tube sheet by the internal application of hydraulic swaging pressure, the flow of pressurized fluid from an adjustable pressure reduction valve is permitted or interrupted by a control valve. An actuator moves the control valve between its flow permitting and interrupting positions in response to a control signal. In the sensor, which is connected to the input and output sides of the control valve, a piston is movable in response to the difference in the input and output pressures to produce the control signal when a predetermined comparative pressure relationship exists.