Abstract: A wrench is disclosed which provides a hydraulically powered ratchet wrench within a compact footprint. One hydraulically powered piston operates to tighten a fastener, while a second hydraulic piston is operable to reset the first piston in preparation for a subsequent tightening operation. An intermediary torque multiplying device may be placed between the driven pistons and the object being acted upon by the pistons. Fluid supply hoses may be coupled to the wrench assembly using a two-axis swivel to facilitate insertion of the wrench assembly into areas that are difficult to access.

Abstract: A wrench with torque augmenting means consisting of an output socket wrench which utilizes a ratchet arrangement and which includes an input cog that is adapted to receive an external drive tool. The input cog constantly rotates under the influence of the external drive tool and a camming surface formed on the arm of the input cog coacts with a cam follower surface on the drive plate of the output to move the drive plate. A spring within the housing of the apparatus connected to the drive plate will cause the drive plate to return to its initial position where the action of the camming surface of the rotating cog arm from the input cog can then repeat its function. Rotary movement of the output in one direction is accomplished during the oscillation of the drive plate by means of the ratchet positioned within the drive plate.

Abstract: A compact hydraulic torque wrench which has an efficient design enabling it to be relatively small in size. The arrangement of the return spring for the hydraulic cylinder provides increased strength and reduces the size of the unit. The device is constructed to enable the drive arm to go through the entire travel without change in alignment. Additionally, the device includes a braking system for the reaction arm to ensure that a ratcheting effect occurs and that the proper return of the hydraulic piston can be accomplished by means of a return spring without the necessity for a hydraulic return of the piston.