Patent GB-755382-A (GB)
Title: Improvements in or relating to well drilling apparatus
IPC: E21B19/20
Filed: 1954-08-13
Abstract: 755,382. Rotary drilling machines. RUSTON-BUCYRUS. Ltd. Aug. 13, 1954 [Aug. 14, 1953], No. 23569/54. Class 85 A rotary well-drilling machine comprises a ground-supported base supporting a derrick, means supporting a vertical traverse frame on said derrick, power means connected to said frame and derrick to move said frame relative to said, derrick, rotary drive power means supported by said frame for vertical movement therewith, nad means connecting a rotary drill bit. to said rotary, drive power means for rotation and vertical 1 movement therewith, said firstmentioned power means including a first motor having a relatively high torque-speed ratio and a second independently operable motor having a relatively-low torquespeed ratio. The machine comprises a mobile base 11, hydraulic jacks 13, a derrick 14, tool-handling unit 15. air compressors 16, compressor motors 17, motor generator set 18 and means for hoisting the derrick, raising and lowering the drill string together with its rotarydrive mechanism, handling drill pipe and propelling the machine. The derrick is raised and lowered by a drum 22 and is provided with gear racks 29 on which is slidably mounted the rotary-drive unit for the drill - tool string, the said drive unit consisting of a reversible D.C. electric motor 31, enclosed gearing 32 and a drive coupling 33 all mounted on a frame 30. The frame 30 is raised and lowered by cables reeved from a drum 37 to a bull reel drum 42 (see also Figs. 9 and 10, not shown). The drum 42 is driven by a motor 43, Fig. 23, through clutches 37<SP>1</SP>, 53 or is driven by a fluid motor 54 through double-reduction gearing and a clutch 59 which is engaged when the clutch 53 is disengaged. Hence drill tools may be lowered by the drum 42 on either a brake 60, 61 or the motor 43, the motor 43 being coupled to the generator 18 as shown in Figs. 26, 27 (not shown) and controlled by the Ward-Leonard system. An auxiliary drum 62 for erecting machinery, handling pipe &c. may be coupled to the bull-reel shaft 48 by a clutch 63 and braked by a band-type brake 64. The clutch 63 is also used to. couple the derrick-hoist sprocket 65 to the shaft 48. The tracks 12 are individually driven and steered through a. pneumatically operated clutch and brake mechanism 71, 73. An automatic brake 87, (see also Figs. 16 and 17, not shown), is provided on the drum 37 for preventing bouncing of the drill bit, (see also Figs. 16. and 17, not shown). The tool-handling unit 15. accommodates four drill pipes which are selectively movable into and out of position over the drill hole. The tool rack 101 (see Fig. 3. also Figs. 4...8, not shown) comprises. plates 102, 103 mounted on a post 104 which is rotatably mounted in bearing. brackets 105, 106, the brackets being connected in turn to a rotatable post 107. Each drill pipe 108 rests on a hook 111 which is'accordingly depressed to actuate members 112, 114, 116 thereby locking the pipe in position, the member 112 being spring-loaded for retraction purposes. The rack 101 is rotated by a fluid motor 131 through a chain and sprocket drive and is locked against rotation about the post 104 by locking bars 124 or 136 which are simultaneously actuated by a pneumatic jack 127 so that the tool 101 is at all times locked against free rotation. The motor 131 is also drivingly connected to the post 107. The bar 136 is normally held in the locking position by a spring 138 and may be released by a lever 139. Each socket, 109 is provided with a set of tool-wrench pawls 145 which are spring biased to automatically engage co-operating notches in the drill pipe. Tool-wrenches are also used to engage the upper end of the uppermost drill pipe and the upper end of the next lower drill pipe. For details of the wrenches (Figs. 18...22, not shown) should be referred to. Specification 755,420 is referred to.