Patent attributes
A hydraulic screw tensioning device for adjusting screws or bolts includes a cylinder supported on a machine part to be clamped by a threaded bolt and nut, at least one piston guided in the cylinder, a change sleeve threaded onto a threaded end of the bolt, a rotary sleeve in the cylinder for positive connection with the nut, first and second gear mechanisms for driving connection with the rotary sleeve and the change sleeve, respectively, a drive motor for the gear mechanisms, a connecting shaft between gears in the second gear mechanism and first gear mechanism, a device for alternative coupling of the drive motor with the change sleeve or the rotary sleeve, and respective recesses or extensions on a gear secured to the change sleeve and on the gear in the second gear mechanism to positively receive a tool for driving the connecting shaft.
