GB635532A - Improvements in or relating to fluid operated percussive tools - Google Patents

Abstract

635,532. Percussive drills. CONSOLIDATED PNEUMATIC TOOL CO., Ltd., and NOBLE, A. April 28, 1948, No. 11659. [Class 124] [Also in Group XXIX] A percussive tool has connections and mechanisms for the admission of dust-laying liquid and motive fluid in succession and means for atomizing the liquid near its point of entry and for conveying it in the atomized condition to the point of discharge. As shown, a connection 5 for dust-laying liquid and a connection 6 for motive fluid are arranged in a head 2 of a body 1. A trigger 4 in the head operates on a valve stem 21 of a valve 20 to cause a groove 27 in the valve to register with a passage 7 from the liquid supply inlet and a passage 13 leading to a venturi tube 16, at the same time a groove 28 in the valve registers with a passage 18 also connected to the venturi tube and a secondary supply of motive fluid from a passage 9, thus producing a stream of atomized fluid which flows through a passage 31 in the body 1 to an annular chamber 32 and finally through nozzles 34 in the front end of the body.' Further depression of the valve 20 urges a thimble 40 by means of a rod 24 having a bore 25 into contact with a shoulder of a cap 37 and closes tubes 39 in the thimble. The hollow rod has a port 26 in communication with the liquid supply and on depression of the valve a port 24a communicating with the bore 25 allows the fluid to pass into a chamber between a fluid control valve 23 and the thimble 40, causing the valve 23 through which the rod passes to move against a spring 22 and bring the main fluid port 8 into register with a groove 35 in the valve and a passage 36 in the body 1 and start operation of the drill. In a modification a drill having a motive fluid valve 45 only, Fig. 2, has screwed into the base of a valve chamber 49 an adapter carrying a fluid inlet 54 and a venturi 66. On operation of the trigger 4 a stem 48 which passes through the valve 45 brings a port in a hollow valve 60 into register with an annulus 57 connected to the motive fluid supply and also a port 67 connected to the venturi 66 into register with an annulus 56 connected to a liquid supply. The liquid is atomized by the motive fluid and a stream of atomized liquid passes through an external tube 68 to a ring 71 having holes therein: Further depression of the stem 48 opens the fluid valve 45 and starts the drill.