Reversing valve insert for a pneumatically driven double diaphragm pump

摘要

A reversing valve insert for the compressed air reversing block of a pneumatically driven double diaphragm pump is described, which has a main valve control piston (52) for reversal of the air chamber connecting lines which consists of a first cylinder insert (54) with connecting bores (108, 218, 224), and of a cylinder piston (52, 252) displaceably arranged therein with annular grooves (212, 220) provided in the piston outer surfaces and connecting the connecting bores (208, 218) with one another according to the piston position, and with an axial bore (223) through which a reversing rod (230), engageable by the diaphragm devices, reaches, the cylinder insert (54) being inserted into a through-hole (282) of the compressed air reversing block and held and sealed on both sides of sealing bush inserts (232), which also form a pressure-tight slide bearing for the reversing rod (230). According to the invention, the main valve control piston (52) is driven by way of a pneumatically operating drive system (232, 96, 230, 120, 110; 100, 122, 140, 142, 255; 118, 110, 114) which comprises an auxiliary valve piston system (87, 100) arranged inside the main valve control piston (52), which auxiliary system is in turn driven by the movement of the diaphragm devices (16) by way of stepped pins (233), which form the rod ends (see Fig. 16). IMAGE