GB149544A - Improvements in or relating to air compressors and in pneumatic tools therefor - Google Patents

Abstract

149,544. Brusa, R. Oct. 1, 1919. Percussive hand tools; percussive drills; dressing by percussion.-An air compressor for effecting alternate increase and release of pressure for the operation of drills, hammers, &c., comprises a cylinder with a single valve operated, in synchronism with the piston, from the driving shaft; the motion of the tool uncovers an aperture for release of the compressed air at the end of the stroke. The use of the apparatus for perforating and engraving marble, granite, &c., drilling blast holes, grooving and picking flagstones &c., is mentioned. Fig. 1 shows a compressor in which inlet of air takes place through apertures 14 and passed a valve 6 normally raised by a spring 13. The valve is actuated by a lever 7 driven from an eccentric 9 on the shaft, and the air is driven out to the tool through an union 10. Two or more air pipes 11, Fig. 8, may be connected to the union each supplying the cylinders E of a tool, the compressor A being mounted, along with an electric motor C driving it, on a three wheeled carriage, the handle of which carries a switch D. The tools are resiliently fixed in the carriage, in the stone dressing apparatus shown, but for drilling blast holes &c. may be connected with it by a hose. Each tool carries a piston 16 working in the cylinder, which, in its outermost position uncovers the seat of a spring pressed valve 17, or a simple aperture whereby air is released. The return stroke of the compressor piston creates a vacuum which retracts the tool piston being assisted by the admission of air through an aperture 20. A hand operated valve 21 regulates the force of the blow by controlling the amount of air passing through. Recoil is prevented by the position of the inlet from the pipe 11 to the tool cylinder, and by the turning of the compressor valve.