GB168452A - A duplex direct-acting pump - Google Patents

Abstract

168,452. Kawakami, S. June 18, 1920. Tappet gears; fluid-actuated gears. - A duplex-acting pump, driven by steam or water power, is provided with a mechanical or fluid-actuated valve-gear, the action of which is independent of the length of the pump stroke. The gear operating the valve of an adjacent cylinder becomes operative at the piston midstroke position and completes the valve movement during a short portion of the stroke. The piston completes its stroke and half of the return stroke before the valve is again operated. Each piston pauses at the end of each stroke until its valve is operated. In the mechanical gear shown in Figs. 4, 5, 12, and 15, the piston-rods 4, 4' are provided with oscillating tappets c, d, c', d<1> the arms of which alternately engage arms a, b, a', b<1> secured in pairs to arms 14, 14' which carry short levers 13, 13<1> connected to the valves 5<1>, 5 of the adjacent cylinders B, A. In the fluid-actuated gear shown in Figs. 19, 23, and 25, the valves 5, 5<1> of the cylinders A, B are worked by auxiliary pistons 23, 24, 23', 24<1> which work in cylinders 25, 26, 25<1>, 26<1> communicating at their outer ends by pipes 27', 28', 27, 28 with auxiliary distributing-valve chests 18', 18, Figs. 29 and 30, which have passages 22<1>, 22, 19', 19 communicating respectively with the exhaust passages by ports 9<1>, 9 and with the main cylinders by central ports 16'. 16. The plug valves 18, 18' are connected by links and levers 15, 15<1>, 12, 13, 12', 13<1> with the piston-rods of the auxiliary pistons. When the piston in cylinder A passes the port 16, fluid is supplied to one of the pistons 23<1>, 24<1> to move the distributing-valve 5<1> and the auxiliary valve 18' into position to effect the reversal of the valve 5 when the piston in the cylinder 13 passes the port 16<1>. A modification is described wherein auxiliary slide valves are used.