Detachable drilling tube/tool joint - produced by pyramidal teeth on tube wall engaging straight tooth groups on tool pad

摘要

A detachable connection between the drilling tool and the drilling tube end is effected by several clamping pads on the tool which can be pressed by hydraulic power against the inside tube wall. The inner wall carries a band of pyramidal teeth which mesh with horizontal and vertical gps. of straight teeth on the clamping pads. Both torques and longitudinal forces are transmitted securely from tube to tool. The coupling operation requires very little time and the change can quickly be made from a rotary drilling tool to a grab-type of drilling tool.