Abstract: A vacuum back-up system for diesel vehicles, and a primary vacuum system for high performance vehicles, which vacuum system includes a vacuum pump for creating a vacuum in an associated reserve vacuum tank connected to the vacuum booster of the vehicle. A relay is attached to the vacuum pump or to a mount bracket which mounts the vacuum pump and the reserve vacuum tank and the relay is electrically connected to a vacuum switch on the vacuum booster and to the vehicle battery and the vacuum pump to facilitate operation of the vacuum pump and maintaining a vacuum of preselected magnitude in the reserve vacuum tank and the vacuum booster.

Abstract: An electrohydraulic drive is provided. High-speed injection valves of hydraulic lift transformers have, for example, a pressure piston driven by a piezoelectric actuator and a reciprocating piston mounted in an axially displaceable fashion in a pressure piston bore and connected to the valve needle. The electrohydraulic drive has a piezoelectric actuator and a hydraulic force/travel transmission of compact design. To ensure the required axial symmetry of the drive despite production-induced tolerances, a balance element supported in a frustoconical depression of the pressure piston is arranged between the piezoelectric actuator and the lift transformer. During assembly of the hydraulics, the element having the form of a spherical segment and produced from high-grade steel can slide freely on the piezoceramic and thus compensate a nonconcentric alignment of the actuator and pressure piston.

Abstract: Pressure adjusting valves (9A, 9B) control outlet pressures of variable throttle portions (8a) of directional control valves (8A, 8B) of closed center type to be kept substantially equal to a maximum load pressure detected by a detecting line (13). A variable throttle valve (40) and a pressure adjusting valve (41) are disposed in a bypass line (5) branched from a pump supply line (3) for controlling an outlet pressure of the variable throttle valve (40) to be also kept substantially equal to the maximum load pressure. The variable throttle valve (40) has an opening area controlled to be reduced with an increase in the input amount by which a control lever unit is operated, and a pump delivery rate is controlled by a tilting control device (2n) to become a flow rate corresponding to the input amount of the control lever unit.

Abstract: In an electric lift truck, an asynchronous electric motor, a reversible sealed pump driven by the motor, communicating with the hydraulic actuators and also with a reservoir, a device which measures the angular position and the angular velocity of the motor, and a control and monitoring unit which causes the motor to be supplied according to the required speed of raising and lowering of the load support and on the basis of data supplied by the measuring device are used for raising and lowering the load support by means of one or more hydraulic actuators. There is a saving of energy in raising; there is also a recovery of energy in lowering, in which the motor acts as a generator to recharge the accumulator batteries of the lift truck.

Abstract: A hydraulic steering arrangement with a steering device (2) and an oil tank (3) which are connected with each other via a supply line (5) and a return line (6), wherein a hydraulic pump (1) is integrated into the supply line (5), has an oil reservoir (7) communicating with the return line (6) and a backpressure valve (8) opening in the direction toward the oil tank (3), which is disposed between the oil tank (3) and the oil reservoir (7).

Abstract: A servo operation apparatus for a transmission comprising an input shaft to which the shift-change operation force is mechanically transmitted from a shift lever, a servo unit for boosting the shift-change operation force by feeding a working fluid, and a valve device which feeds the working fluid to, or drains the working fluid from, the servo unit depending upon the shift-change operation of the shift lever, wherein provision is made of an working fluid feed control means which feeds the working fluid in such a manner that the pressure of the working fluid in the servo unit is raised with a steep gradient in the former half until a predetermined initially raised pressure value is reached and, thereafter, is raised in the latter half with a gradient less steep than that of said former half.

Abstract: A travelling control circuit for a hydraulically driven type of travelling apparatus is provided. The circuit has a hydraulic pump, left and right hand side directional control valves provided parallel to each other in a discharge path of the hydraulic pump, a left hand side first and second circuit and a right hand side first and second circuit. Furthermore, the output sides of the left hand side and right hand side directional control valves are connected with a left and right hand side travelling purpose hydraulic motor, respectively. In addition, a pressure compensating valve is provided with each of the first and second circuits to control the opening between an inlet port and an outlet port in response to a difference in pressure between a self load pressure and a maximum load pressure of the load pressures of the left and right hand side travelling purpose hydraulic motors, thereby compensating a pressure in the fluid.

Abstract: A pneumatic circuit for use in causing rapid, upward movement of a piston and cylinder device in a glass machine incorporates a supplementary valve which connects an upper part of the cylinder to exhaust for part of the upstroke, and through a restrictor valve to exhaust towards the end of the upstroke.

Abstract: The invention concerns a control valve with a housing, having a pump connection, a tank connection device, a working connection device and a load pressure connection device, each connected with an opening device in a control surface, and with a slide, arranged movably in the housing and co-operating with the control surface, the slide having grooves and/or channels, so that it connects or separates predetermined opening devices with/from each other. In such a control valve the tightness must be improved. For this purpose an additional auxiliary tank connection device is provided, which is connected with an auxiliary tank opening device in the control surface. The slide has an auxiliary tank pipe or groove, which, in its neutral position, connects the auxiliary tank opening device with the load pressure opening device.

Abstract: The invention relates to a drive system for a hydraulic press. The drive system is of the type of secondary controlled system maintaining an impressed pressure of substantially constant magnitude in a pressure system. A hydraulic transformer comprises a pair of mechanically coupled hydrostatic machines each having a variably capacity. The first machine is connected to the pressure system and the second machine to the press cylinder. The invention provides a drive system in which biasing the press cylinder, rapid tranverse and pressing stroke, decompressing the fluid and flushing of hot fluid is accomplished in a closed loop free of throttling losses. The hydraulic transformer further allows to recover energy to the pressure system.

Abstract: An automatic transmission, in particular an infinitely variable automatic transmission for motor vehicles, contains a radial piston pump (1) for supplying a hydrodynamic converter (3), a lubricating device and control and actuating devices of the automatic transmission via a number of control conduits. Radially outside of its outlet valves, the radial piston pump (1) contains an annular chamber (22), which extends around the radial piston pump (1). The annular chamber (22) is embodied as a damping chamber and is mainly arranged in a recess (23) of the converter housing (2), and therefore almost completely outside of the pump housing (17). The annular chamber (22) is bordered by the recess (23) of the converter housing (2), the pump housing (17) and/or a separate pump cover (24). The annular chamber (22) is not symmetric and with its volume extends into the adjoining free spaces of the automatic transmission.

Abstract: A vacuum brake booster with an automatic braking actuation system of the type which includes an electric actuator assembled with a power piston to effect forward movement of a valve plunger assembly when activated under control of an electronic controller, wherein a depression amount of a brake pedal is detected to calculate a depression speed of the brake pedal based on the detected depression amount, and wherein the electric actuator is activated when the calculated depression speed of a brake pedal exceeds a predetermined threshold value and is deactivated when a release amount of the brake pedal is more than a predetermined value.

Abstract: In a servo valve for hydraulic power steerings of motor vehicles which consists of a rotary spool valve having a rotary spool rotatably disposed in a control sleeve, a front end of the control sleeve and a flange structure on the rotary spool have spaced oppositely arranged faces forming a gap therebetween in which a C-shaped spring is disposed which extends around the rotary spool and has free opposite ends in engagement with pins projecting axially toward one another from the opposite faces of the control sleeve and the flange structure when both are in a center position relative to one another so as to bias the control sleeve and the flange structure into such center position with a predetermined spring force.

Abstract: A method of suppressing vibrations of an actuation element of a hydraulic force transmission apparatus, especially a hydraulic clutch actuation system in an automobile, and an auxiliary vibrator for carrying out the method, are disclosed. The force transmission apparatus possesses a transmitter cylinder connected to the actuation element, and also a receiver cylinder connected to that cylinder by a liquid column, by which receiver cylinder a low-frequency excitation vibration is transmitted to the liquid column, which propagates in the latter as a low-frequency pressure pulsation.

Abstract: An exhaust gas control device is provided in an internal combustion engine. In the device, a valve which comprises a valve head and a valve stem is provided in a body the axis of which is inclined at 45 degrees with respect to a horizontal exhaust pipe. The valve is moved up and down in the body by compressed air and a coil spring. When the valve is engaged on a valve seat in the exhaust pipe, the exhaust pipe is closed, so that exhaust gas flows through a by-pass pipe. When the exhaust pipe is opened, exhaust gas flows through the exhaust pipe, thereby improving engine performance.

Abstract: The invention provides fluid handling apparatus which may be heat exchange apparatus or fluid reaction apparatus. The apparatus is provided with an interrupter structure for disrupting the fluid boundary layers at the walls of the apparatus and promoting mixing of the separated boundary layers with the adjacent core layers. One interrupter structure comprises a plurality of longitudinally-spaced interrupter elements mounted on a core rod, each element comprising a plurality of blade-like members each of at least approximately spherical segment profile in side elevation, the members extending mutually radially outward relative to one another to touch or nearly touch the said surface or surfaces adjacent the elements. The elements are spaced longitudinally from one another the distance required to provide wake interference flow of the fluid, wherein the vortex upstream of one element cooperates with the vortex downstream of the next element in the fluid path.

Abstract: An environmental control system having an ozone decomposition catalyst coating in the hot pass side of the primary heat exchanger. The environmental control system includes primary and secondary heat exchangers as well as a rotary compressor and a rotary turbine expander. The environmental control system is used in aircraft for providing conditioned air to the habitable space of the aircraft for life support purposes.

Abstract: A heat exchanger of the type incorporating an auxiliary cooling device includes an envelope with inlet and outlet windows for conducting a primary heat transfer medium through the envelope. A bundle of heat exchange tubes is mounted in the envelope with corresponding first ends of those tubes being located adjacent to the inlet window and corresponding second ends of the tubes being located adjacent to the outlet window. First and second collectors are in fluid communication with the tube ends for conducting a second heat transfer medium through the tubes. The auxiliary cooling device is positioned in the inlet window and surrounds the tube first ends and a ferrule projecting upwards from the envelope from the inlet window therein surrounds the cooling device to direct the primary heat transfer medium through the cooling device and into the inlet window of the envelope.

Abstract: A tube-and shell double-pipe or liquid-air fin type heat exchanger, which offers a high level of thermal energy transfer efficiency, incorporates a rotary blade to disrupt a fluid film on surfaces of each tube, and is of uncomplicated design and construction. The blade is free-floating and operates regardless of the direction of flow of the liquid through the tubes.

Abstract: In a heat exchanger comprising a plurality of plates arranged adjacent to each other and defining between them passages for heat exchanging fluids, the plates are provided at their corner portions with openings, the fluids being conveyed to and from the passages via said openings. The openings for one of the fluids are located at one side of the plates and the openings for the other fluid are located at the other side of the plates. The plates are provided with a corrugation pattern which varies in a direction transverse to the flow direction in such way that the passages are narrower shallower at the side of the plates at which the inlet and outlet openings of the respective passages are provided and wider deeper at the opposite side.