GB356421A - Improvements in and relating to valve apparatus for rock drills and like fluid pressure operated tools - Google Patents

Abstract

356,421. Valve gear for rock-drills and percussive tools. RAYNER, G. H. T., 14, Broomhall Road, and RAYNER, P. T., 37, Ashland Road, both in Sheffield. Aug. 7, 1930, No. 23701. [Class 122 (ii).] A rock-drill o percussive tool is provided with a distributing valve having three heads of equal diameter ; the central head controls the admission through passage 8; the end heads control the exhaust through passages 11, 12. Passages 9, 10 connect the chest with the cylinder ends ; supplementary ports 17, 18 connect these passages with the valve-chest ends. Exhaust ports 13, 14 controlled by the piston 19, and channels 19, 20 are arranged in the cylinder. Passages 15, 16 connect the valve-chest ends with grooves 19, 20 which are constantly open to atmosphere. In the position shown, the left-hand valve-chest end is open to reduced pressure through port 18, the left-hand cylinder end is open to pressure, and the right-hand ends of the valve-chest end cylinder are open to exhaust. When the piston passes port 13, the left-hand end of the cylinder begins to exhaust, and cylinder pressure passes through channel 19 and passage 15 to the righthand end of the chest and reverses the valve against the reduced pressure in the other end. Specification 356,437 is referred to.