Abstract: The invention concerns a hydraulic amplifier for a braking system incorporating a body (10, 110), a first component (18, 124) capable of being displaced in the body (10, 110) under the effect of the operation of a brake pedal, between a first position causing a first chamber (16), joined to a braking circuit, to communicate with a low pressure reservoir (44, 138), and isolating this chamber (16) from a high pressure source (32, 130), and a second position isolating the chamber (16) from the low pressure reservoir (44, 138) and causing it to communicate with the high pressure source (32, 130), characterized in that it incorporates a second chamber (12, 112) formed in the body (10, 110), a circuit (42) causing this second chamber (12, 112) to communicate with the low pressure reservoir (44, 138), and a valve means (34, 116) responsive to the pressure of the high pressure source (32, 130) normally closing this circuit under the effect of the pressure of the high pressure source (32, 130).

Abstract: The present invention relates to a hydraulic power booster, in particular for the actuation of a master cylinder in an automotive vehicle brake system, wherein there is a booster piston and a brake valve arranged essentially in parallel to the booster piston. In response to an actuating force applied to on a brake pedal, pressure fluid is adapted to be metered into a booster chamber of the hydraulic power booster, the booster chamber being confined by a pedal-operable rod and by the booster piston. In the presence of relatively small actuating forces at the brake pedal, the wheel brakes connected to the working chamber of the master cylinder are supplied with at least the absorption volume required. The booster piston has a projection at the end remote from the pedal extending into a blind-end bore of a master cylinder piston. A hydraulic connection between the blind-end bore and the booster chamber is adapted to be closed by a pedal-operable valve assembly.

Abstract: The device incorporates an actuating piston (6) in tandem with a master cylinder piston (7) both defining first (8) and second (9) braking pressure chambers. A valve mechanism (34), in line with the control valve mechanism (12) of the device, is controlled by a mode selector piston (31) exposed to the actuating pressure coming from the source of fluid under pressure (25) so as normally to isolate the first chamber (8) of the braking circuit (I) joined to the working chamber (5). In the case of failure of the pressure source, the braking circuit (I) is joined to the primary chamber (8).

Abstract: A brake booster includes a housing with at least three bores to movably carry a pair of pistons and a valve assembly. A diaphragm is exposed to a fluid pressure differential to pull the pair of pistons and the valve assembly to a brake applied position wherein braking fluid pressure is generated in all three bores.

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 brake unit comprising a hydraulic booster unit connected to hydraulic auxiliary energy and controllable by a brake pedal via a control piston drives a master brake cylinder unit to supply brake pressure to wheel brake cylinders through at least one hydraulic line connected to an output of the master brake cylinder unit. A bypass line connected to the work chamber of the booster unit supplies a preliminary feed of the auxiliary energy to the wheel brake cylinders to overcome the brake clearance. A two way, two position changeover valve is connected to the hydraulic line, the bypass line and the wheel brake cylinders to connect during a braking operation either the bypass line or the hydraulic line to the wheel brake cylinders dependent on the pressure in the two lines. This brake unit requires only a few hydraulic connections external of the unit, has a single construction, has small dimensions, has exact operation and has quick response.

Abstract: Chuck installation with a cylinder and piston for fluid operation of the chuck jaws, providing a plunger projecting into the cylinder and movable in opposite directions for decreasing and increasing the volume of the cylinder and thereby increasing and decreasing the pressure of the operating fluid therein, and operating means, including weights, turning with the chuck and responsive to centrifugal force of these weights to force the plunger deeper into the cylinder for increasing the pressure of the operating fluid therein and thereby counteract operational centrifugal force of the jaws in operation of the chuck.

Abstract: In a boosted hydro-pneumatic drive for rapid traverse and power stroke, particularly for driving punching tools, a cylinder housing (1, 4) with partition (12), a disc piston (7) with plunger (8), a working piston (2) which can be loaded with compressed air for the return stroke and an annular piston (9) surrounding the plunger (8) are provided. The cylinder spaces between the working piston (2) and the annular piston (9) on both sides of the partition (12) are filled with hydraulic oil.In order to reduce the consumption of compressed air and to increase the speed of response, and for the purpose of simplification, the working piston (2) is provided with an annular surface (16a) which can be loaded with compressed air in the direction of advance, and a compression spring (10) is clamped between the disc piston (7) and the annular piston (9). The space accommodating the compression spring (10) is in constant connection with the outside air, preferably via a filter (11).

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: 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 surrounded by 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 can activate a warning when the piston travel is not in a predetermined relation to the applied fluid pressure.

Abstract: An operator cylinder comprising, in combination with a hydraulic piston-cylinder unit, an idle transmission piston for supplying to the hydraulic cylinder a pressure of control, and a stress multiplier for supplying when necessary an increased pressure simultaneously excluding the operation of the transmission piston.

Abstract: The method and apparatus for producing an oil well, by the provision of a pumpjack unit which reciprocates an engine assembly located within the upper extremity of a wellbore. The engine assembly has a power piston which hydraulically drives a lift piston by means of hydraulic fluid being transferred therebetween. The lift piston is directly attached to and reciprocates a string of sucker rod, which in turn reciprocates the downhole production pump.The hydraulic fluid associated with the engine assembly is contained within a closed system, and the relative sizes of the power and lift pistons are of a ratio to cause the lift piston to travel a greater distance respective to the power piston, thereby enabling a relatively short stroke of the polish rod to impart the piston of the subsurface pump with a relatively larger stroke.

Abstract: In a power-operated hydraulic booster for a vehicle braking system pressurization of a power chamber in a housing on one side of a boost piston is controlled by an assembly of at least two separate spool parts which work in bores in the boost piston and the housing, and a boost chamber is defined in the housing between the power chamber and an output piston having an effective area less than that of the boost piston.