Abstract: In a pneumatically driven power torque wrench comprising a frame stopped from movement relative to a related structure, a hydraulic cylinder and ram unit carried by the frame, a work output shaft rotatable relative to the frame and coupled with work to be turned in axial alignment therewith, a lever arm with one end freely rotatably engaged about the shaft and its other end drivingly coupled with the cylinder and ram unit; and ratchet means between the shaft and lever arm. The ratchet means comprises a ratchet wheel about the shaft and a plurality of circumferentially spaced spring-loaded pawls pivotally carried by the lever arm and engaging the wheel. The shape and the circumferential spacing of the teeth on the wheel and the pawls are such that when rotary driving engagement is established between the shaft and the lever arm, the central rotative axes of the work, shaft and said one end of the crank are concentric, independent of any bearing support between the shaft and the frame.

Abstract: A pneumatically driven power torque wrench comprising an elongate frame with front and rear ends, a transversely extending drive shaft rotatably carried by the frame at the front end thereof; a ratchet drive to rotate the shaft and including a ratchet wheel on the shaft; a drive ring about the wheel; circumferential pawls between the wheel, the ring and an elongate lever arm projecting from said ring. The wrench further includes a cylinder and ram unit fixed to and extending between the lever arm and the rear end of the frame and a work-engaging tool carried by the shaft, at one end thereof, and engaging a fastener concentric therewith. The wrench next includes a reaction device to anchor the rear end of the frame against rotation about the axis of the shaft.

Abstract: A torque limiting device engageable with and between a rotating power shaft and piece of work to be torqued, including a drive section connected with the power shaft and having a plurality of circumferentially spaced sockets, a driven plate with through openings normally registering with said sockets, drive balls normally engaged in and extending between the said openings and sockets, an elongate torque shaft with one end coupled with the plate and its other end connected with said work, a keeper plate overlaying the said openings in the driven plate to hold the balls engaged in said openings and sockets and having pockets normally circumferentially offset from said openings, a body, means connecting the body in predetermined rotative position with the torque shaft, spring means normally yieldingly maintaining the keeper plate in normal rotative position relative with the body, said pockets being circumferentially offset from said openings a distance equal to the circumferential deflection of the torque shaft

Abstract: A torque multiplier tool engageable between a torque wrench and a piece of work, said tool comprising a body with an elongate support engaging reaction arm to stop rotating of the body, a wrench engaging input shaft rotatably carried by the body, a work engaging output shaft rotatably carried by the body spaced from and parallel with the input shaft, an input pinion on the input shaft, an output gear on the output shaft, a pair of idler units including idler shafts rotatably carried by the body and carrying driven gears and drive pinions engaged with the input pinions and the output gear at circumferentially spaced points between which a number of whole teeth and one-half of one tooth of said input pinion and of said output gear occur, whereby driving engagement through the tool is established by four engaged driving teeth three-fourths of the time and by three engaged driving teeth one-fourth of the time.