Patent ID: 7322430
Filing Date: 2008-01-29
Classification: E21B

Abstract:
1. Apparatus for reducing the torque required to provide relative rotation of two connected members comprising: an impact member adapted to provide an impact to at least one of the connected members; driving means for driving the impact member, wherein said driving means is operable to cause the impact member to automatically and repeatedly impact upon said at least one member: and wherein the apparatus is configured so that in use the impacts do not impart substantial torque on said connected member wherein there is provided biasing means for biasing the impact member towards a position in which said impact member is to be retained when said apparatus is not in operation, wherein the biasing means is operatively mechanically coupled to the impact member in order to bias said impact member, but may be decoupled from said impact member so as to be operatively decoupled when the impact member is driven by the driving means.