Abstract: A compressor assembly for use with a Pulse Tube cryocooler is disclosed. The compressor assembly includes a central hub having a plurality of faces, and at least four compressor modules mounted on the central hub. Each of the compressor modules is mounted on a face of the plurality of faces. Each compressor module comprises a piston mounted in the central hub and configured to reciprocate along an axis of travel within the central hub. The pistons are mounted head-to-head with each other and collective reciprocation of the pistons along the respective axes minimizes vibration forces of the compressor assembly in X, Y, and Z translational axes of motion.

Abstract: A device for straightening the body and the structures of a damaged vehicle, includes a master cylinder filled with hydraulic fluid, wherein moves a master piston under the action of a rotary member actuated by a motor. A slave cylinder is connected to the master cylinder through a flexible conduit extending from said master cylinder, and is designed to be connected by some means to the body or to the structure to be straightened. The slave cylinder receives a slave piston, driven in translation inside the slave cylinder under the action of the hydraulic fluid, so as to be urged to strike the neighbourhood of the end of said slave cylinder connected to the body or to the structure, by being subjected to a return force tending to bring it back to its initial position.

Abstract: A hydraulic system for motion amplification is disclosed. The system provides hydraulic fluid on both sides of a pair of hydraulic cylinders, creating a pressurized closed loop which provides precision control during both forward and reverse strokes of each hydraulic piston.

Abstract: Drive is transmitted from a cam to a push rod via a body of liquid trapped between two pistons. A control element is normally urged against a seat by pressure in the body of liquid but can be lifted off its seat by the application of pressure to liquid in a control chamber. When the control element moves clear of its seat, liquid trapped between the pistons acts on a seat-engaging face of the control element and displaces the control element instead of driving the push rod.

Abstract: Hydraulic pulse generating apparatus for actuating one or more slave motors, comprises at least one hydraulic master cylinder, which in use is connected to a slave motor by flexible tubing or otherwise.The master cylinder is fitted with a reciprocating plunger which is operated by power actuated driving means, and the cylinder communicates with a hydraulic fluid reservoir which is maintained at a pressure intermediate the maximum and minimum pressures produced in the cylinder by operation of the plunger.Manual control means are provided, to prevent the transmission of pressure pulses to the motor while the power actuated driving means continues to operate and for this purpose the master cylinder preferably communicates with a transfer chamber, the volumetric capacity of which is variable by operation of the manual control means.Means are also provided whereby, when the capacity of the transfer chamber is thus increased beyond its normal capacity, the further inflow of fluid from the reservoir is prevented.

Abstract: A chamber of an actuating mechanism is hydraulically connected to the under-the-piston cavity of the cylinder adjacent to the housing of a pulsator. Built into the piston is a spring-loaded valve serving as a device for compensating for the leakage of liquid from the chamber and for protecting the latter against overload pressure. During the operating stroke of the piston, the valve is brought in contact with it by an eccentric, and in case the pressure is increased or it is necessary to compensate for the leakage of liquid, a clearance is formed between the valve and the piston for the liquid to pass the direction of the liquid flow being dependent on the pressure differential on the valve.