DRILLING DERRICK BLOCK AND TACKLE LIFT LIMITING APPARATUS Russian patent published in 1995 - IPC

FIELD: drilling rigs. SUBSTANCE: drilling derrick block and tackle lift limiting apparatus has system to control block and tackle position and position of boom of stands allocating mechanism, pneumatic distributor, tap to discharge air from tyre-pneumatic coupling, throttle washer, pneumatic cylinder of brake, driving mechanism, braking belts. In air feeding line between pneumatic distributor and pneumatic cylinder of brake there is mounted in parallel to each other maximum pressure valve and electropneumatic valve, coil of which receives power during time relay contacts make. Throttle washer is set at output of electropneumatic valve. Apparatus has high speed of operation due to brake pneumatic cylinder fast filling with compressed air. Simultaneously, due to maximum pressure valve braking instant force is graduated in accordance with need to keep right way of cable winding up drum. Due to high speed of operation braking way is decreasing, that correspondingly allows to make height of drilling derrick lower. EFFECT: drilling derrick block and tackle lift limiting apparatus is used in drilling rigs. 1 dwg