LOCKOUT MECHANISM FOR GRIPPING TOOL

A secondary latch mechanism (also referred to as a lockout mechanism) for a gripping tool, such as a casing running tool (CRT), prevents activation of the CRT prior to full insertion of a tubular workpiece into the CRT. When embodied in a CRT, the lockout mechanism prevents activation of the CRT unless a fully-inserted tubular workpiece applies a selected axial load to a bumper mounted on the CRT. The lockout mechanism is operable between a locked state and an unlocked state. In the locked state, the lockout mechanism prevents relative axial movement between the CRT cage and mandrel, and keeps the CRT slips retracted away from the workpiece. When in the unlocked state, there is no significant restriction to the normal movement of the CRT components, and the CRT functions as if the lockout mechanism were not present.