Abstract: An assembly for tensioning cables on a percussion hammer or the like wherein each cable has a threaded end fitting. The assembly includes a lock nut threadably mounted on the end fitting for locking the end fitting relative to the hammer. Also included in the assembly is a jacking sleeve threadably mounted on the end of the cable fitting and adjacent to the nut. A hydraulic jack body is mounted around the jacking sleeve and nut and abuts a portion of the hammer at one end thereof. The jack body includes a hydraulic cylinder and piston wherein the piston is mechanically connected to the jacking sleeve by a split ring. Movement of the piston due to the introduction of hydraulic fluid into the chamber imparts a corresponding movement to the jacking sleeve resulting in tensioning of the cable.

Abstract: There is provided an improved percussion hammer having tie cables connecting the base of the hammer body with the upper cylinder. Cable tensioning jacks are used for preloading the tie cables. Each cable tensioning jack includes a jack body having a central opening for securing a cable, and having an annular groove defining a jack cylinder closed at one end and open at the other. An annular jack piston is slidably received within the jack cylinder. The annular cylinder is pressurized to expand the jack. In one embodiment of the invention high pressure grease provides the source of pressurized fluid.