GB190205031A - Improvements in Pneumatic Hammers. - Google Patents

Abstract

5031. O'Donnell, J. P., [Kimman, H. J.]. Feb. 27. Percussive hand tools.-A pneumatic hammer for riveting &c. has a solid piston 2 and a distributing- valve 11 working longitudinally in a taper bushing 10, which fits in the cylinder and is kept in place by a plug 25 screwing into the bushing. The throttle valve 7 is actuated by a trigger 9 and is pressed back to close the opening 8 by a spring. The forward movement of the distributing-valve is assisted by a spring 26. The ports and passages are arranged so that during the forward motion of the piston motive fluid reaches the cylinder by the passages 12, 13, 14 and the exhaust takes place through openings 20 and through channels 15, openings 23, space 16, an opening in the bushing, openings 21, 22 in the cylinder, and openings 19<a>, Fig. 8, in the handle base. The valve is moved into its forward position by motive fluid entering the channel 17 and passing into and behind the valve by openings. The motive fluid now passes from the channel 14 to the channel 15 by the openings 23 and the exhaust takes place through channel 18 and openings 19, 21, 22, 19<a>. Cushioning takes place behind the piston on the return stroke. The valve is returned to the position shown by motive fluid leaking past the flange X and acting on the differential areas of the flanges X<1>, Z. In a modification, a leakage passage is made through the flange X<1>.