GB546420A - Improvements in and relating to pumps - Google Patents

Abstract

546,420. Reciprocating pumps. HUNT, W. F., and HUNT, O. F., [Representatives of ZWICKY, J.]. Jan. 28, 1941, No. 1141. [Class 102 (i)] A pumping plant, suitable for the operation of hydraulic jacks or the filling of reservoirs under pressure, comprises . a high-pressure pump having its inlet connected to the delivery side of a double-acting lowpressure pump of greater volumetric capacity, the two pumps having a common operating means, a common piston rod 21, and a common delivery chamber 13 into which the low-pressure pump delivers through a non-return valve 14, and a hand-operated valve 17 for by-passing the low-pressure pump when the pumps are operating against a considerable back pressure. The low-pressure pump may be of the kind described in Specifica- tions 218,379, [Class 102 (i)], or 538,870, and is supplied through an inlet 9, a non-return valve 15 (not shown), and a filter 8. The highpressure pump comprises a hollow displacing plunger 25 loosely fitting in a cylinder 19 and connected there with by a non-return valve 24, and delivery ports 26 leading through a non- return ball-valve 27 to the common delivery chamber 13. A screw-down relief valve 28 retains the valve 27 in position and connects the chamber 13 with the inlet side of the filter 8. This relief valve may be used to drain the apparatus. In a modification the stem of the valve 28 is within the filter. A two-way or a three-way distributing valve 29 may direct the liquid to either or both of a pair of hydraulic jacks.