DEVICE FOR LIFTING OF DRILLING PIPE STRING Russian patent published in 1997 - IPC

FIELD: mining industry. SUBSTANCE: device is installed above drilling rig. Drive unit in device is made in the form of upper stationary rope-suspended part and lower movable part, such as cylinder with movable rod. Provided are upper and lower grips together with levers. Lever of upper grip is pivotally connected with upper stationary part of drive unit. Lever of lower grip is pivotally connected with lower stationary part of drive unit. At lifting of lower grip, pipe string is wedged in it and also lifts upwards. At this time, upper grip turns at certain angle and passes pipe. When upper grip lowers, upper grip is wedged and holds pipe string. Thus alternate gripping is performed. Device cuts hand labour at raising drill pipe string and accelerates round-trip operations in drilling holes. EFFECT: high efficiency. 1 dwg