GB819385A - Drilling rig - Google Patents

Abstract

819,385. Boring earth. FAILING CO., G. E. Jan. 29, 1957, No. 3158/57. Class 85 [Also in Group XXX] In a drilling rig comprising a mast 4 pivotable on a vehicle to raised and lowered positions, a crosshead 71 slidable on the mast above a rotary table 7 on the vehicle when the mast is raised, and power operated chains 88, 89 driving the crosshead during drilling, the chains do not interfere with the operations of raising and lowering the mast and are arranged to be immediately operative upon raising the mast. The mast is pivoted about trunnions 10, 11 on standards 8, 9 fixed to the vehicle, is held in the raised position by catches 26, 27, and is held in the lowered position on a rack 42 by clamps 49. The mast is moved by a piston and cylinder 59, 57 pivoted to the vehicle and mast at 58 and 62, and supplied with hydraulic fluid through pipe 72 connected with a reservoir 73 and a pump 74. The pump is driven from a transmission unit 76 driven from the motor of the vehicle and having power take - off connections 77,...80 driving respectively the pump 74, the rotary table 7, a draw-works 6, and a pump 5. Drilling fluid, drawn by the pump 5 through a hose 65 and a cooler 66 from a slush pond, is supplied by a pipe 67 and a hose 68 to a switch 70 mounted on the crosshead. A kelly 87 (Fig. 3) running through the rotary table during drilling connects the crosshead with the drill pipe 86. Backup tongs are mounted on the standard 9 to facilitate making and breaking drill pipe joints. Each of the power operated chains has one end connected to the crosshead, passes over a sprocket 92 or 93, has the other end connected to a cable 1@ running over pulleys 103 or 104 and back to the crosshead. The sprockets are driven by chains from a transmission unit 115 driven by a fluid motor 118 connected by duct 119 to the pressure side of the pump 74 and discharging through duct 120 and cooler 66 into the reservoir 73. In the lowered position of the mast the chains 88, 89 are kept taut by engagement with shoes 128, 129 mounted on the standards and by movement of the pulleys 103, 104 which have spring mountings. Hoisting cables 63, 64 run from the draw-works over pjulleys 24, 25. The kelly is raised and lowered in the mast by the cable 63, and the cable 64 carries a hoisting plug 87<SP>1</SP> (Fig. 1) which may be screwed into the drill pipe for hoisting the pipe from the hole or for hoisting additional pipe sections. The transmission unit 76 may be driven from a motor additional to that driving the vehicle.