Patent ID: 6189631
Filing Date: 2001-02-20
Classification: E21B

Abstract:
A drilling tool with extendable elements, being movable between a retracted position and an extended position, comprising:a mandrel assembly having an upper connection at the top for attachment to a drill string component, a central bore throughout, and an upper mandrel portion having an externally tapered bottom;a housing assembly located in axially slidable, and rotationally engaged relation with the mandrel assembly, a central bore throughout, a plurality of slots, and a connection at its bottom for attachment to a drill string component; and,a plurality of lugs located one each within the slots, the lugs having a conically tapered surface engagable with the externally tapered bottom when the tool is in the retracted position, the lugs having curved inner surfaces engaging the upper mandrel portion when the tool is in the extended position.