GB787961A - Metering pump - Google Patents

Abstract

787,961. Reciprocating pumps. MASHINTER, W. H. May 31, 1955 [July 14, 1954], No. 15668/55. Class 102(1). A reciprocating pump for delivering measured quantities comprises a closed bellows 70, loaded by a spring 78, which has its interior connected to liquid in a reservoir 22 through passages 62, 60 and pulsations are applied to the liquid by a piston 23 having an inclined control edge 65 that co-operates with the port 60 to determine the amount of liquid trapped between the piston and the bellows ; the piston is rotated by a knob 55 through pinions 52, 53 to adjust the stroke of the bellows. The piston is'maintained against an eccentric ring 36 by a spring 48 and the bellows 70 has a rod 76 which enters a guide sleeve 77. The pressure of the pulsations is limited by a relief valve. A non-return valve or a valve attached to the bellows is located between the bellows and the piston to ensure liquid is trapped in the bellows to prevent a collapse when the liquid to be metered is.supplied under pressure. The pumping space 28, for the liquid to be metered, has a series of inlet valves 86, each comprising a lightweight plate of substantially triangular shape and the delivery side has a valve of similar shape and also a spring-loaded lift valve 90. A valve 113 permits release of air and vapour. The spring 78 may be replaced by a tension spring within the bellows.