Abstract: An axial plunger pump for high pressure purposes using three plungers in a star like arrangement around an axis of a wobble plate. Each plunger has associated therewith a pumping unit and all pumping units are located in a common pumping unit block and each of the pumping units comprising a pump chamber having inlet and outlet valves connected to a common inlet duct and outlet duct respectively. Plunger cylinders of at least one of the plungers are connected to pump chamber at a position between the inlet valve and the outlet valve while the plunger cylinder of at least another plunger is connected to the associated pump chamber at a position below the inlet valve.

Abstract: An apparatus having latching effect for limiting pressure in liquid feeding systems has a valve means inserted in the feeding path of a pump supplied liquid. The valve means includes a shunt valve opened upon excessive output pressure; the shunt output of the shunt valve is connected to a feed-back tube. There is further provided a back-stroke valve in the main feeding path of the liquid. A first pressure switch has the output pressure applied thereto while to a second pressure switch the input pressure at the shunt valve is applied. The two pressure switches are inserted into the switch-on circuit of the pump in such a manner that the pump is switched-on in the presence of a low output pressure and switched-off in the presence of an excessive output pressure.

Abstract: A valve arrangement is disclosed for controlling the supply of an operating fluid, having a casing with an inlet port, a main flow path provided with a non-return valve extending from the inlet port to an operating outlet port and a secondary flow path extending from the inlet port to a by-pass outlet port, the secondary flow path containing a ball applied to a valve seat under spring prestressing to close said secondary flow path, there being provided a piston including a tappet operable to displace the ball from the seat, a spring for biasing the piston away from the ball, a flow path including a restrictor communicating pressure from the main flow path to said piston to displace the piston against the spring following an excessive rise in pressure in the main flow path, the structure permitting a predetermined stroke of the piston against the force of the spring prior to displacing the ball from its seat via the tappet.