Abstract: A pump including a cylinder body having first and second ends and a cylinder bore, a plug shaft including first and second ends and a plug shaft bore, wherein the first end of the plug shaft is fixed relative to the cylinder body, and wherein the second end of the plug shaft includes a stop, a first piston received within the cylinder bore to partially bound a first gas chamber and a hydraulic fluid chamber, the first piston being received over the plug shaft and axially moveable relative to the plug shaft, a socket shaft including first and second ends and a socket shaft bore, the socket shaft bore being configured to sealingly receive the plug shaft, a second piston received within the cylinder bore to partially bound a second gas chamber and the hydraulic fluid chamber, the second piston being connected to the socket shaft.

Abstract: A pulse hydraulic system is disclosed comprising, in combination a hydraulic sump for supplying the system with hydraulic fluid, one or more hydraulic pumps taking suction on the sump for increasing the pressure of the hydraulic fluid exiting the sump, a pulse generator fed by the discharge from the pump(s) for creating pulsed pressure of the hydraulic fluid output therefrom, an actuator coupled to the pulse generator for doing work, and one or more accumulators coupled between at least one of the pump(s) and the pulse generator, between the pulse generator and the actuator, and between the pulse generator and the sump for storing and supplying pressurized hydraulic fluid to the system. The addition of one or more pulse intensifiers to a pulse hydraulic system increases the overall system efficiency.

Abstract: A master cylinder for a two-circuit brake system which includes anti-skid control has two separate chambers and pistons. The main control piston is associated with an auxiliary piston which it engages after a predetermined amount of travel. The auxiliary piston has an extension which holds the brake control valve and which is opened by the control piston during its travel. Furthermore, the second circuit cylinder includes a pressure sensor which cooperates with double pistons which can activate a warning when the piston travel is not in a predetermined relation to the applied fluid pressure. Also included is an electronic switching circuit and associated valve mechanism for imparting a pulsating stroke to said double pistons.

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: 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: 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.

Abstract: A method of controlling the advance and retraction of a tool on a processing machine in dependence of mechanical properties of the workpiece which tool communicates hydraulically on one hand with a drive means and on the other hand via a shut-off member on by-passes, with a pressure converter, the closing or opening of the shut-off member taking place through electrical pulses of a pressure measuring element, the pressure produced during the flow of the pressure fluid through an adjusting valve being kept constant, increasing, or decreasing for respective time periods each, the setting of the adjusting valve being operated by a pressure control for producing constant increasing, or decreasing pressure, and the pressure produced by the pressure converter and causing the retraction of the tool starting immediately after completion of its advance and being kept uniform, and an apparatus for carrying out the method.