Patent ID: 6553873
Filing Date: 2003-04-29
Classification: B25B

Abstract:
A wrench assembly for use with a source of pressurized hydraulic fluid comprising:a hydraulic wrench comprising a hydraulic cylinder having a retraction side and an extension side, said cylinder configured to extend and retract a pawl; a drive head containing a plurality of teeth radially disposed on said drive head, said drive head further comprising a socket configured to engage a threaded member, whereby rotation of said drive head will effect rotation of said socket and of any threaded member which said socket may have engaged; wherein said hydraulic cylinder and said drive head are positioned relative to one another to allow said pawl to engage said teeth on said drive head upon extension of said pawl, whereby extension of said pawl will effect rotation of said drive head; a hydraulic motor configured to rotate said drive head at a higher speed and lower torque than said cylinder and said pawl; and a hydraulic fluid distribution system comprising: a pressure line connecting said hydraulic motor and said hydraulic wrench to said source of pressurized hydraulic fluid said pressure line having a cylinder branch configured to provide hydraulic fluid to said hydraulic cylinder of said hydraulic wrench, said cylinder branch having an extension branch and a retraction branch; a tank line providing for discharge of said hydraulic fluid from said hydraulic wrench and said hydraulic cylinder; and an operator control valve having a manually selectable first, second, and third position, wherein said operator control valve is configured to direct hydraulic fluid to said retraction side of said cylinder when said operator control valve is in said first position; wherein said operator control valve is configured to direct hydraulic fluid to said hydraulic motor and to said retraction side of said cylinder when said operator control valve is in said second position; and wherein said operator control valve is configured to direct hydraulic fluid to said extension side of said cylinder when said operator control valve is in said third position.