GB1334715A - Pumping apparatus - Google Patents

Abstract

1334715 Reciprocating pumps OTTO ENG Inc 23 June 1971 [24 June 1970 14 June 1971] 29429/71 Heading F1A A pump for supplying liquid, e.g. viscus resin, to a mixer comprises a cylinder with inlet and outlet chambers 253, 261 and a piston 225 with a bore 291 communicating at 293 with the inlet chamber and via radial openings 292 with the outlet chamber, a seal 270 being positioned such that communication with the outlet chamber is prevented, as shown, until, during the discharge stroke, communication with the inlet chamber is cut-off by piston 225 entering bore 245, liquid then being discharged from bore 245 through the piston bore and openings 292 to the outlet chamber. Alternative arrangements of seal 270 are described, Figs.3 and 6 (not shown). Check valve 295 is optional. Leakage liquid on the ' piston is removed by solvent in a chamber 283. Two pumps may be operated simultaneously to supply resin and hardener in predetermined proportions to a mixer, Figs.1 and 7 (not shown), the proportions being set either by an adjustable stop limiting the piston stroke, Fig. 2 (not shown), by adjusting the throw of a crank driving the piston, Fig.5 (not shown), or by adjusting the lever arm length on one side of an air motordriven lever pivoted at its centre and connected at each end to a pump, Fig.7 (not shown). The pump may be driven by a double-acting air motor coupled directly to the pump piston or via a crankshaft. Alternatively, the pump may be driven on its discharge stroke by air supplied to a motor piston, and on its suction stroke by hydraulic fluid applied to the opposite side of the motor piston, the speed of the discharge stroke being controlled by the setting of a needle valve in the hydraulic fluid connection, Fig. 1 (not shown). In Fig.5 (not shown), the pump is mounted on a stand.