Abstract: A spring actuated plunger work support seeks variable tolerance level of workpiece and is hydraulically locked in place to provide resistance to workpiece deflection imposed by processing loads. A collet with independent steel segments in a molded rubber body are preloaded in assembly and actuated by conical ended hydraulic piston having minimum travel to lock the work supporting plunger.

Abstract: A master cylinder and proportioning valve therefor comprises a housing forming a bore with a piston movable therein and a porportioning valve engageable with the piston to control operaton of the proportioning valve in response to movement of the piston.

Abstract: A fluted piston for a volume-compensated pressurized adjustable length positioner. The cylinder is charged through the charging/discharging valve so that the opposed fluid chambers defined inside the cylinder bore by the slidably movable piston are filled with compressible fluid at elevated pressure. An actuating rod in the piston operates a valve in the piston to open communication between the opposed chambers and allow selective extension and retraction of the piston rod. The large-diameter piston rod has an elongated head configuration formed by flute ribs. These ribs provide bearing support for the extended piston rod and create a volume compensating space in the piston head to account for the large ratio of extended-rod cylinder volume to retracted rod cylinder volume.

Abstract: A hydraulic vehicle brake system having a brake booster disposed in a housing. The brake booster communicates via an energy supply system with a supply container and via shutoff devices with brake chambers that can be acted upon by plungers via the brake booster. The brake chambers are connected in turn via brake lines and incorporated shutoff valves to wheel brake cylinders of wheel brakes. A stop bushing surrounds the master cylinder piston and has a sleeve, and a spring is disposed between the sleeve and an annular stop integral with the housing. The stop bushing, an inner plunger face and the housing enclose a plunger chamber. In regulated operation, the plunger chamber likewise communicates with the energy supply system via the brake booster and corresponding lines. During normal brake operation the plunger chamber is connected to the supply container via a line connected to a reversible valve.

Abstract: In a light alloy piston for internal combustion engines, a fibrous insert body is embedded in the cast material adjacent to each of the bosses defining the piston pin bores. In order to minimize the costs of manufacturing such piston, the fibrous body extends only above the horizontal plane which includes the piston pin axis between that plane and the piston head and on both sides of the plane which includes the piston pin axis and the piston axis extends over not more than the load-carrying length of the boss defining the piston pin bore.

Abstract: Pistons are described having oval polar profiles or both oval polar profiles and axial profiles machined to asymmetric curvatures about the plane which includes both the piston axis and the minor axis over at least a part of the skirt length, the asymmetry of the polar profile comprising a greater convexity about the major axis on the thrust face over at least part of the axial length of the skirt region.

Abstract: An air motor 24 which may be employed in a mine drilling apparatus includes a hollow body 26 formed of a plastic material, and a driven shaft 38 rotatably supported by the body 26 and incorporating a valve assembly 34. The body 26 has opposing pairs of external faces 58 within which are mounted metal cylinder sleeves 29 which receive pistons 30. A cylinder head 31 of plastic material closes each cylinder 29 and a piston rod couples opposing pairs of pistons 30 and engages the shaft 38 so that power may be transmitted to this driven shaft 38.

Abstract: A master cylinder for a vehicle braking system comprises a body (2) with a bore (3) open at the rear end of the body, a reservoir (4), a transverse port (17) in the body opening into the bore (3) and positioned rearwardly of the reservoir, and a passageway defined between the exterior of the body (2) and a sleeve (22) mounted thereon to communicate the transverse port (17) with a chamber (7) of the reservoir. in different disclosed embodiments the sleeve may be integral with the housing of a booster assembled with the master cylinder and an element may be interposed between the sleeve and the master cylinder body and be provided with a tubular extension interconnecting the reservoir with the passageway.

Abstract: A variable-capacity water pump includes a pump impelled fixed to a rotatable shaft for forcibly feeding cooling water from a cooling water passage, a mechanical seal disposed behind the pump impeller, a temperature sensor such as a thermostat mounted on the rotatable shaft and disposed in the cooling water passage for detecting the temperature of the cooling water, a thrust shaft disposed coaxially with the rotatable shaft and axially movable by the temperature sensor, and a disk secured to the thrust shaft for axial movement therewith, the disk being axially movable by the temperature sensor for varying a range of operation of the pump impeller. In response to a variation in the temperature of the cooling water, the temperature sensor axially moves the thrust shaft and hence the disk to vary the range of operation of the impeller, thereby changing the quantity of the cooling water flowing through the water pump.

Abstract: The device comprises a pilot slide (27) controlled by a pressure differential (P-P') determined by an electromagnetic pilot valve element (43) located in a return circuit to a tank (7) which is common to both the hydraulic installation and a branch pipe (8). The device preferably includes an isolating valve (40) connected to the pilot valve element (43) so as to isolate a pilot chamber (30) in the event of a failure of the electromagnetic actuator.

Abstract: An impact relief valve and apparatus is disclosed which includes a hydraulic pump connected by two feed lines to a hydraulic cylinder. A first feed line provides fluid below a piston of the cylinder and the second feed line provides fluid above the piston providing a means to cause reciprocal motion of the piston within a cylinder housing. The piston is provided with at least one impact relief valve adapted to be opened upon impact of the piston with the housing at the top of the stroke of the piston whereby when fluid from the first feed line pushes the piston to the top of its stroke, the impact valve or valves are caused to open allowing any additional fluid pressure from the first line to pass through the second feed line to a suction side of the pump thereby reducing power requirements for the pump. An annular ridge on the cylinder head opens the impact relief valves.

Abstract: A gas cylinder for applications requiring height adjustments such as found in chairs, stools, or like structures supported by columns. The cylinder has an elongated rechargeable unit of double-wall construction provided with a springless check valve inside a fluid port thereof preferably all of molded plastic. A single-piece sealed plunger assembly includes a single actuating rod with velocity controls incorporated therein which permit vertical extension from collapsed to fully-extended positions. Depression of the actuating rod allows circulation of the pressurized fluid between the chambers, with pressure force acting to extend the plunger when the unit is unloaded. When the unit is loaded, the plunger can be retracted.

Abstract: An electrohydraulic system for control of a variable output pump includes a microprocessor-based controller receiving inputs from condition sensors coupled to the pump and command inputs from a remote master controller. The controller supplies outputs to an electrohydraulic valve for metering hydraulic fluid to a pump control port and thereby controlling pump operation in any one of a number of preselected and prestored pump control modes. A hydromechanical valve is connected in parallel with the electrohydraulic valve for controlling pump operation in the event of electrical malfunction or failure. Circuitry connected between the pump condition sensors and the control computer prevents aliasing errors due to mismatch between the computer sampling frequency and pump speed. A pump torque sensor measures pump input shaft torque.

Abstract: Fluid flow control valves are provided having a jet pump or aspirator connected to a plurality of fluid passageways. Fluid flow from one of the passageways through the jet pump creates a partial vacuum enabling fluid flow to be drawn through the other of the fluid passageways connected to the jet pump. Such valves enable hydraulic fluids of a single-acting piston-cylinder unit or the like to be readily exhausted.

Abstract: A master cylinder has a pressure cylinder and an outwardly projecting mounting flange mounted thereon by arms extending longitudinally of the cylinder in spaced relationship therewith and being connected to the cylinder at locations remote from the flange outside the area swept by seals carried by a piston. The cylinder, flange and arms are formed as an integral plastics molding.

Abstract: A cylindrical casing accommodates an operator pistion and a power piston separated by a fixed barrier which serves to define with the former a reservoir and with the latter a power chamber. A piston rod affixed to the operator piston extends through the barrier into manual brake actuating relation with the power piston. Hydraulic fluid under pressure is introduced to the reservoir from which it flows through barrier passages, past a check valve, into the power chamber and out through venting ports formed in the piston rod. To apply vehicle brakes linked to the power piston, the operator piston is manually propelled toward the barrier, and the power piston is thus forced away from the barrier by the piston rod, resulting in rapid transfer of hydraulic fluid from the reservoir to the power chamber. The venting ports then close, such that the power chamber is pressurized to exert a brake power assisting hydrostatic force on the power piston.

Abstract: The proportioning valve assembly (40, 140) may be screwed into a complementary-shaped opening in a master cylinder (10). The valve assembly (40, 140) includes a differential area piston (50, 150) biased by a spring (70, 170) toward the outlet (21, 121) which communicates with the rear brakes. The master cylinder (10) includes a pair of passageways (16, 18) which communicate primary fluid pressure and secondary fluid pressure directly to the differential area piston (50, 150) of the proportioning valve assembly (40, 140) to displace the piston (50, 150) to a balanced position. If there is a failure of pressure in the primary brake circuit, the proportioning valve assembly (40, 140) actuates the differential area piston (50, 150) to permit fluid flow to bypass the piston (50, 150) and be communicated directly to the rear brakes of the vehicle.

Abstract: In a two-stage reaction device for vacuum brake boosters, the clearance at the piston rod will be reduced by the piston rod acting directly on the valve piston which comprises a head portion connected via a neck portion at its end close to the vacuum chamber. The head portion and the rear end surface of the valve piston contain abutment surfaces which cooperate with levers. The levers, in turn, are moved by the push rod coupled to the master cylinder via a fork-like shaped pressure member with prong-shaped attachments. In this arrangement, one end of each lever is held resiliently between a supporting ring and a spring plate, with the supporting ring including edges about which the levers are tiltable when the pressure member acts on the other ends of the levers.

Abstract: In the hydraulic breaker according to the present invention, oil pressure at a fixed value always flows in the circuit at a low pressure side whenever the piston is raised or lowered, to prevent the need for an accumulator in the circuit at the low pressure side. At the same time, a high pressure oil is required during the raising and lowering of the piston, bringing about less of a change in the surge pressure, attributing to the fact that there is no need for an accumulator in the circuit at the high pressure side. Moreover, the hydraulic breaker of the present invention is advantageous by providing an increased striking force because the high pressure oil is used, in addition to the reaction force of the compressed nitrogen gas, when the piston is lowered to strike the chisel.

Abstract: A rotary actuator having a housing defining an opening, an output shaft extending through the opening, a stator vane and rotor vane associated with the output shaft and opening to define a plurality of actuation chambers and an inner surface of the housing extending inwardly past a shoulder portion of the output shaft to seal directly against the shaft.