Patent ID: 6733414
Filing Date: 2004-05-11
Classification: B25B,B25F

Abstract:
An impact wrench comprising:a tool housing; a motor supported by the tool housing and connectable to a power source, the motor including a rotatable drive shaft having a gear end, the motor being operable to drive a tool element for working on a workpiece; a gear assembly including a gear assembly housing supported by the tool housing, a ring gear supported by the gear assembly housing, one of the gear assembly housing and the ring gear having an end defining a first bearing race, a planetary gear carrier member supported for rotation relative to the ring gear and defining a second bearing race, the carrier member being drivingly engageable with the tool element to drive the tool element, a plurality of planet gears supported by the carrier member and drivingly connectable to the gear end of the drive shaft, the plurality of planet gears interacting with the ring gear to rotatably drive the carrier member, and a plurality of bearing members supported between the first bearing race and the second bearing race; a drive assembly drivingly connectable between the gear assembly and the tool element, the drive assembly including a cam shaft connected to the carrier member for rotation with the carrier member, a ram member drivingly connected to the cam shaft and including a ram lug, and an anvil member including an anvil lug engageable with the ram lug to drive the anvil member, the anvil member being drivingly connectable to the tool element to rotatably drive the tool element; wherein said impact wrench is selectively operable to drive the tool element in a forward direction and in a reverse direction, wherein the cam shaft defines a helical first groove and a helical second groove, wherein the drive assembly further includes a cam ball engageable between the cam shaft and the ram member to connect the ram member to the cam shaft for rotation with the cam shaft, the ram being axially movable relative to the cam shaft, wherein, during operation in the forward direction, the cam ball is movable in one of the first groove and the second groove, and wherein, during operation in the reverse direction, the cam ball is movable in the other of the first groove and the second groove; wherein at least one of the first groove and the second groove has an extended axial length; and wherein the first groove has a first axial length, and wherein the second groove has a second axial length, the second axial length being less than the first axial length.