EXPANDABLE DOWNHOLE TOOL

摘要

The present invention provides a down-hole tool (7) with at least one radially outwardly deployable tool element (33) for use in a bottom hole assembly (1) provided with a pressurised down-hole motor drive fluid supply (50). The tool (7) comprises a body (9) having at least one tool element (33) having a mounting, proximal, end portion (32) pivotally mounted (31) on said body, and a working, distal, end portion (34) displaceable between a stowed, radially inward, position and a deployed, radially outward, position. The proximal end portion (32) is provided with an engagement portion (29, 30) formed and arranged for driven engagement with a drive member (23) axially displaceable by a piston and cylinder device (19, 20). In use of the tool (7), axial displacement of the drive member (23) causes said proximal end portion (32) to rotate and displace said tool element working end portion (34) between said stowed and deployed positions thereof.