Abstract: A pressure switch valve which briefly raises a pressure during switching of the valve. The pressure switch valve has a cylindrical chamber with a first ball that engages a valve seat of an inflow conduit. A second, spring-loaded ball is supported on the first. Both balls are longitudinally movable with slight radial play in the cylindrical chamber. An outflow conduit branches off from the cylindrical chamber at one point in such a way that upon switching of the valve, a normal plane containing the spherical center of the first ball toward the valve seat and extending at right angles to the longitudinal axis of the chamber does not reach the mouth cross section of the outflow conduit until a corresponding normal plane of the second ball toward the spring has already exited from the mouth cross section.

Abstract: A detachable intake neck connection for a pump which prevents aspiration of air into the hydraulic pump if a suction line is missing. The hydraulic pump has a first neck bore that, communicates with a suction chamber, which tightly receives an intake hose nipple of a suction line. The pump has a second neck bore for a pressure line, this second bore communicates with a pressure chamber. A connecting bore 31 that communicates with the pressure chamber of the pump begins at the neck bore for the intake hose nipple and is tightly closed by the intake hose nipple introduced into the neck bore. If the intake hose nipple is missing, the pressure chamber of the pump is short-circuited to the suction chamber through the connecting bore. A buildup of pressure in the pump and hence pumping of air is therefore precluded, the hydraulic pump is usable for instance for hydraulic vehicle brake systems, in which for safety reasons, the aspiration of air into the brake system must be prevented.

Abstract: A brake system having a pressure control valve assembly with an inlet valve in a brake line between a master brake cylinder and a wheel brake cylinder. The brake system is also equipped with a precharging pump and a return pump. A charging valve is disposed in a feed line connecting the two pumps. In phases of brake pressure holding and brake pressure reduction upon traction control, the pumping of brake fluid through the continuously operated return pump by the precharging pump is intended to be suppressed. When the precharging pump and the return pump are driven by a common drive motor, the charging valve, which is embodied as a 2/2-way valve, assures that when the anti-skid system becomes operative an exchange of brake fluid between the precharging pump and the return pump is suppressed. When the traction control becomes operative, contrarily, the valve enables pumping of brake fluid from the precharging pump to the return pump, but only whenever the pressure control valve is switched for pressure buildup.

Abstract: An arrangement for centering an end wall of a housing of a hydraulic gear machine, such as a pump or a motor, with respect to the open end of an internal chamber provided in a housing body forming the circumferential wall of the housing includes a plurality of pins which are received in a press-fitting manner in bores of the end wall and protrude beyond an end face of the end wall which faces and closes the open end of the chamber in the mounting position. The pins may have contact surfaces which are turned to the same diameter as the corresponding inner surface of the housing body which bounds the open end of the chamber, or they may exactly fit into the open end, or overlap slightly with the inner surface in which event some material displacement or deformation takes place during the assembly of the end wall with the housing body.