453,435. Deep-boring plant. MULLER, F., 170, Lainzerstrasse, Vienna. March 6, 1935, No. 7079. Convention date, March 6, 1934. [Class 85] [See also Groups XIX and XXIV] Rotary deep-boring apparatus includes means for indicating the torque that is being transmitted and adjustable means for interrupting the drive when a torque of predetermined magnitude is exceeded. In Fig. 1, concentric driving and driven shafts are connected through pinions carried thereby and meshing with double pinions 6.. 9 carried by a drum 10 engaged by adjustable brake shoes 13, 14, the lower shoe 14 being connected by rods 18 to a plunger 21 acting through fluid to compress gas in a chamber 23, the chamber 23 carrying a gauge 25 for indicating the torque. The shoe 14 is also connected through rod 27 with a dash-pot 28 and a cable or rod 30 controlling drill lowering means. If the drill encounters excessive resistance, the drum 10 slips. Springs may replace the hydropneumatic means 21 .. 23. In Fig. 3, a sprocket 40 drives a shaft 41 with a pinion 42 engaging planet wheels 43 carried by a hollow shaft carrying the brake drum 52; the planet wheels 43 also mesh with internal teeth in a casing 47 which drives sprocket 48. In Fig. 5, an inner driven shaft 65 drives through bevel planetary gear an outer shaft driving through spur gearing a shaft 78 from which the machine is driven ; the planet gears 62 are carried by the inner member 68 of an adjustable cone friction brake, the outer member 70 of which carries a toothed segment 76 acting on a rack 77 connected to lever 79 which bears against a spring 83 adjustably stressed by hand wheel 84, screw 85 and abutment 87. The torque is indicated by a piston 89 compressing fluid acting on a gauge 93. The rack 77 may be locked by a pin 101 and is connected through rack and pinion gearing 96 with an adjustable dash-pot 94; it is also connected to means controlling the drill lowering means preferably through a rod 117, Fig. 9 and slide 114 adjustable by a screw 115 in a lever 110 connected to the rack by links 112. The lever 110 may carry a second adjustable slide 114 with connections adapted to stop the drive or put the drawworks out of action when the lever 110 moves excessively owing to the drill rods breaking. In a modification, Fig. 14, a gear 125 fixed to the drive shaft 65, is adapted to give a reverse drive through gear 126, the two drives being alternatively connected through friction or dog clutches 128, 129, with common control means 131 connected through bevel gearing 133, 134 to means controlling a brake 130 on the driven shaft 78, whereby the brake is applied when both clutches are disengaged and is out of action when either clutch is engaged. In Fig. 15, the torque indicating means 150 is mounted on the shaft of the bevel pinion which drives the rotary table, and acts through rack 152 and spring 153, the rack being also connected through lever 155 to means controlling the drill-lowering device. In Fig. 18, the driven shaft acts through the torque-indicating means 160 and reversing gearing to drive a shaft 97 from which the rotary table is driven, and also acts through automatically-controlled reversing bevel gearing 164, 165 and worm gearing 166, 167, to drive the drawworks drum. The torque is indicated by the rack 172 acting through an adjustable spring 175 and screw 176 on a beam 179 bearing on an oil container 180 connected by pipe 181 to a gauge 182. A modification of this form shows this mechanism mounted with the driving motor and the hoisting drum in a common frame. The clutches of the bevel reversing gear are controlled by a pinion 231, Fig. 22, meshing with a toothed segment or the torque indicating means and carried by a shaft 232 moved axially as the torque varies by engagement of a steep thread with a nut 233 ; the nut may be adjusted by hand through rack 234 and pinion 235. In Figs. 24 and 25, the driving shaft 250 may drive a shaft 259 at any one of four speeds through gears 251 . . 258 and the shaft 259 may drive the drum 269 at any one of eight speeds through gears 260 .. 263, 265 .. 268. The shaft 259 may also through gears 255, 270 .. 272, drive a shaft which may drive shafts 276, 281, directly through gears 277, 278, 280, or through torque indicating means 273 and gears 274, 275, 279. The clutches of the gears 279, 280, may be automatically controlled by means as in Fig. 22. Shaft 276 drives the rotary table, while shaft 281 may drive the drum 269 through worm gearing 282, 283, or may drive through gears 285..288 a shaft carrying cat-heads 284 and a drum 285 by which pressure may be applied to the tool when commencing boring. Electromagnetic brakes or clutches may be used and switched off automatically when a given maximum torque is reached.