Patent ID: 6488323
Filing Date: 2002-12-03
Classification: B66C,E21B

Abstract:
A friction grip apparatus, for gripping a cylindrical member about its external diameter without causing surface or structural damage to said cylindrical member, for use in conjunction with means to axially rotate said cylindrical member, or secure said member against rotation, comprising:a. a rigid, generally cylindrical outer sleeve having an axial bore slightly larger than the external diameter of the cylindrical member to be gripped, and having a somewhat larger annular shaped central cavity therein; b. an elastic flexible liner securely attached to no more than one-half of the radially inward face of the annular shaped cavity of the outer sleeve; c. an inner sleeve, disposed within said flexible liner, said inner sleeve having one side securely attached to said flexible liner, and its opposite side forming an internal annular bladder between said inner sleeve and said flexible liner by being releasable from the flexible liner, such that said flexible liner may move radially inward in response to fluid pressure between said inner sleeve and said flexible liner; d. a torque transmitting bushing, securely attached to at least one-half of the radially inward face of the annular shaped cavity of the outer sleeve; and, e. means for introduction of or withdrawal of a desired amount of fluid pressure into or from the annular bladder, so as to cause a desired amount of radially inward force to act on said cylindrical member within said friction grip apparatus.