Hydraulic clamp

摘要

A hydraulic clamp comprising an assembly of concentrically-arranged parts wherein axial movement of a first part effects rotation of a second part and axial movement of a third part effects a corresponding axial movement of the second part and wherein the first part controls supply of pressure fluid to the third part so that rotation is first imparted to the second part and thereafter axial movement is imparted thereto and wherein a clamp arm is fixed to said second part.