F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
F15B13/00—Details of servomotor systems ; Valves for servomotor systems
F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
F15B13/06—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with two or more servomotors
B—PERFORMING OPERATIONS; TRANSPORTING
B66—HOISTING; LIFTING; HAULING
B66D—CAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS
B66D1/00—Rope, cable, or chain winding mechanisms; Capstans
B66D1/02—Driving gear
B66D1/08—Driving gear incorporating fluid motors
E—FIXED CONSTRUCTIONS
E21—EARTH OR ROCK DRILLING; MINING
E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
E21B19/008—Winding units, specially adapted for drilling operations
B—PERFORMING OPERATIONS; TRANSPORTING
B66—HOISTING; LIFTING; HAULING
B66D—CAPSTANS; WINCHES; TACKLES, e.g. PULLEY BLOCKS; HOISTS