Patent GB-190417414-A (GB)
Title: Improvements in and connected with Rock Drilling Engines.
Inventor: ROUDEBUSH FRANK LLOYD
Filed: 1904-08-10
Granted: 1905-05-11
Abstract: 17,414. Roudebush, F. L. Aug. 10. Rock drills ; laying dust in mines.- In a rock drill which may be used in mining or for working stone, a piston serving as a valve is reciprocated in a cylinder by means of compressed air and is adapted to strike the end of a drill bit or chisel mounted in the cylinder. The drill is fed forwards bodily by means of a rear piston extension which may slide in a fixed cylinder and is acted on by the operative fluid. An adjustable supporting-column is provided, and in some cases the feed-member may be detached and the drill used as a hand tool. A piston 2 enlarged at the rear end is provided with radial passages 37, 38 and an axial passage 36, and may slide in a cylinder 1 having its bore in two diameters 3, 4 to fit the piston. The cylinder 1 is provided with an annular inlet port 7 and a port 17 which is open to the atmosphere through passages 21. A collar 20 fixed in the head of the cylinder is formed with a central hole which is polygonal at its rear end and fits the drill shank 40. In operation, air enters through a pipe 13, acts upon a shoulder 135, and moves the piston 2 rearwards till the shoulder 135 enters a chamber 6, when exhaust takes place through the body of the piston and the passages 21. At this stage, the passages 38 register with the inlet 7 and air may flow to the rear of the cylinder, thus cushioning the piston 2 and driving it outwards At each stroke of the piston, a portion of the operative fluid enters an axial aperture 41 formed in the drill 40 and clears the point of the drill. The air exhausted through the passages 21 serve to prevent the dust ejected from the shot hole from covering the drill: A cylindrical cap 22 is formed with a threaded hole 44 in which is mounted a rod 45 provided with a piston capable of sliding in a cylinder 47, secured on the column 68 and having an escape aperture near its forward end. The cap 22 fits over the rear end of the cylinder 1 and is provided with a screwed end 26 gapped to form four fingers which fit over flats formed on the cylinder 1. A nut 25 having an inturned end is screwed on the cap and provided with a collar 28 having a series of ratchet teeth 29. When the drill is working, the operator grasps the nipple 10 and rocks the drill cylinder 1, and with it the drill bit and the feed-piston, through an arc of a circle. In order to prevent unscrewing of the nut 25, a pin 31 acted upon by a spring 33 is adapted to engage the ratchet teeth 29. When it is desired to unscrew the nut, the pin 31 may be moved out of engagement with the ratchet teeth and locked back by means of a stop-pin 134, the pin 31 being formed with a recess 234 which may be engaged with the stop-pin 134 by turning the pin 31 through an arc of a circle. The drill 40 is provided with an axial aperture 41 and an enlarged circular head 142 formed with V-shaped lips 43 separated by longitudinal channels 143. A standard for supporting the drill consists of a column 68 having a serrated foot 75 and a bracing-bar 176 mounted in a foot 79. A clamping-box is mounted on the column 68, one part being adapted to embrace the cylinder 47 and the other part to embrace the column. The column member is made in halves 65, 165 clamped together by means of bolts 69. The part 165 is provided with a bevelled disc 166 carrying the halves 72, 172 of the drill-embracing member, which are connected by a bolt 73 and may be gripped round the cylinder 47 by means of a bolt 71. In some cases, a rear projection 61 formed on the cylinder 47 may abut against a socket piece 265, the cylinderembracing member 64 not being used. Water may be used to actuate the feed-piston, and in some cases to remove dust from the drill hole.