GB286101A - Bore-hole apparatus - Google Patents

Abstract

286,101. Capeliushnicoff, M. A. March 21, 1927. Borehole apparatus.-In borehole and well-drilling apparatus in which the cutter spindle is driven by a hydraulic motor arranged in an inner casing at the foot of an outer casing through which the driving fluid passes, and wherein the inner casing can be raised or lowered independently of the outer casing, the whole or part of the weight of the outer casing may be transmitted to the tool. The outer casing 2 is closed at the top and water is supplied through a pipe 10 to drive a hydraulic motor 40 which drives the cutters 34; the water afterwards passes through the drill stem to the cutters. The motor casing is locked against rotation in the outer casing by a tongue and groove connection 38 and is held in its working position therein by twoarmed levers 19 pressed by spring strips 22 into engagement with an annular recess 21 in the casing 2. Packing 11 is provided. When repairs are required for the motor, cutters &c., a sleeve 28, Fig. 3, internally bevelled at the lower end. is lowered to engage the upper ends of the levers 19 to free the latter from the casing 2, hooks 32 at the ends of the levers then engaging a shoulder 33 in the sleeve 28 ; the motor &c. is then raised by a cable 25b. To return the motor &c., the head 24 of a spindle 25, Fig. 2, is engaged with recesses 26 in the levers 19 and the motor is lowered by means of a cable 25<a>. the spindle 25 being released from the levers 19 when the latter are pressed by the springs 22 into engagement with the recess 21. The cutters 34 are pivoted to allow for their passage through the casing 2, and are afterwards forced into cutting position by springs.