Patent GB-401490-A (GB)
Title: Improvements in hydraulic feed for rotary drilling
IPC: E21B19/08
Filed: 1932-11-04
Abstract: 401,490. Well-drilling plant. FORTUNE, J. C., 1006, Roosevelt Street, Monterey, California, U.S.A. Nov. 4, 1932, No. 31184. Convention date, Nov. 7, 1931. [Class 85.] In hydraulic feed mechanism for a rotary drill comprising hydraulic power cylinders in which work piston members carrying a yoke with a bearing for rotatably supporting a string of drill pipe the hydraulic cylinders are rockably supported on a base frame and a movable guide frame is provided for positioning and holding the cylinders. A rotary table 11 mounted on a derrick floor 12 drives a square kelly 13 connected with drill pipe 15 by a joint 16. In the cellar 17 is assembled a base frame comprising bars 23 bolted to spacing bars 25 and having sockets 24 to receive the lower ends 29 of hydraulic cylinders 19, the bars 23 being anchored to concrete flooring 27. A guide frame 20 is assembled to hold and position the cylinders, the frame comprising bars 32 bolted to spacing bars 35, the former carrying circular guides 33 and the latter being fitted with screw jacks 36 by which the frame may be raised, lowered, or levelled. The frame may be adjusted laterally by screw jacks 38 thrusting against the bars of the frame, plumb line means being preferably provided so that the guide frame may be accurately centred over the base, the cylinders being then lowered through the guide rings 33 to rest in the sockets 24. The piston members are preferably rams 45, Fig. 4, or when a downward pull is required a piston 47 and piston rod 46, Fig. 7, may be used. The ram 45, Figs. 4 and 8, which is of less diameter than the inside of the cylinder so that water from an inlet port 73 can pass down and under the head of the ram, is guided at the upper end of the cylinder by a bearing bushing 70 on the cylinder and at its lower end is fitted with a bearing bushing 71 grooved in parts at 72 to allow water to pass. A solid non-grooved portion of the bushing 71 is arranged in alignment with the water inlet port 73 to act as an automatic cut-off as the ram nears the top of its stroke, the ram being finally brought to rest by contact of the bushing 71 with the bushing 70. The piston members carry a yoke 21 removably connected to the piston members by pins 43, secured to the yoke by nuts 50, which enter sockets 44 in the rams 45 or piston rods 46 and are secured by cross pins or keys 48. A bore 42 in the yoke 21 accommodates the bearing for the drill pipe which comprises a casing 51 seating on the yoke and held in position by pins 94 engaging flanges 95, a sleeve or bushing 55, and thrust bearings 52, radial bearings 53, and combined thrust and radial bearings 54. The sleeve or bushing 55 is formed at its upper end with a socket 57 to receive slips 58 to grip the stem or pipe, the slips being released from the stem or pipe by means of cables 66 connected with arms 67 attached to a collar 59 on the neck of the bearing, cam means being provided so that on rotation the collar rises and engages conical rolls 64 connected to the slips. The water supply connections to the cylinders include a pressure release valve and means whereby either of the pistons or rams may be operated independently, so that, after removing the kelly and supporting bushing out of the yoke, the yoke may be disconnected from one of the rams and that ram lowered, the yoke being then swung about the pin connecting it to the other ram and, if desired, lowered on to the derrick floor. More than two cylinders may be used if extra power is required..