Kombinert styring for griping med rörklave- og spiderkilebelter

摘要

Apparatus for gripping and releasing a tubular and comprising an elevator (13) having slips (15) for gripping and releasing a tubular (39,40). A spider (12) has slips (14) for gripping and releasing the tubular (33). A mechanically operated valve (18) is provided for controlling the supply of pressurised fluid to move the spider slips (14) between a gripping position and a release position, with sensor means (28) detecting when the elevator slips (15) are in the gripping position. Means (31) mechanically inhibits movement of the valve (18) to a position in which the spider slips (14) release the tubular (40) when said sensor means (28) detects that the elevator slips (15) are not in a correctly gripping position.