Abstract: This invention pertains to an impact wrench mechanism and a clutch therefor, wherein a motor having an output shaft rotatably drives a carrier member mounted on an axis. Anvil jaw(s) rotatably and coaxially mounted adjacent the carrier member have impact jaw(s) extending radially therefrom. Hammer member(s) having impact jaw(s) for impacting with the anvil jaw(s) is (are) mounted on the carrier member for rotation therewith and for limited linear motion relative thereto in a direction essentially transverse to the axis of rotation to allow the hammer member impact jaw(s) to contact the anvil jaw(s). The line of force of the impact blow has a force component tending to urge the hammer member(s) out of engagement with the anvil jaw(s), but the hammer member(s) have a mass and a mass center location such that linear inertial force is created which prevents motion of the hammer member(s) during the impact blow.

Abstract: This invention pertains to a rotary impact tool and a clutch therefor, wherein a motor drives a carrier cage or member within which is pivotally mounted one or more swinging hollow hammer members. An output shaft extends through the carrier member and through the hollow hammer member and includes forward and reverse impact anvil surfaces. The hammer member is, or members are, mounted to swing in respect to the carrier member as the hammer member(s) rotate(s) with the carrier member, and carries forward and reverse impact jaws on its internal surface. As the clutch is driven in the forward direction by an air motor or the like, the forward impact jaw is moved in and out of the path of the anvil jaw on the output shaft by cam action, and during an impact blow the inertia of the rotating hammer member(s) act automatically to hold the impact jaw in engagement with the anvil jaw.