GB299383A - Improvements relating to fluid operated metal and other grinding or cutting machines - Google Patents

Abstract

299,383. Gear Grinding Co., Ltd., and Orcutt, A. H. July 25, 1927. Driving machines.-In a fluid operated metal or other cutting or grinding machine, the supply system includes a rotary valve which is operated by a reciprocatory part of the machine for throttling the supply of fluid to the working cylinder when the ram is approaching the end of its stroke and a chamber d of variable volume containing a loaded movable piston is provided to absorb sudden pressure fluctuations. In the application to a gear grinding machine, the slide p carrying the grinding-wheel g and the plunger c operating the indexing mechanism are respectively operated by fluid pressure cylinders g, h supplied by a pump a through a distributing valve r, fluid being returned to the reservoir t by a pipe s. The chamber d carries a piston e which is loaded by a spring f or by a dead-weight or by compressed air. The throttling at the ends of the stroke is effected by a rotary valve i operated through gear wheels j, k, l by abutments o mounted on the slide p. As the plunger approaches the end of the stroke one of the abutments engaged a fixed tappet m<1> to move the valve to reduce the fluid supply. On the return stroke the valve is returned by the engagement of the same abutment with one of the spring tappets m.