Abstract: A hydraulic coupling device, comprising a coupling unit, a holder block, and a lock nut. The coupling unit is mounted to the holder block by means of the lock nut, which is tightened in a thread at the nose end of the coupling unit. The lock nut has a rotationally symmetrical outer contour. A plurality of grooves distributed around the circumference are recessed in the outer contour. The grooves extend axially inward from the end of the lock nut facing away from the holder block. The invention also relates to a lock nut for a hydraulic coupling device.

Abstract: The invention relates to a tool holder for cranes. The tool holder comprises hydraulic cylinder means arranged to detachably be able to lock a tool to the tool holder. Furthermore, hydraulic coupling means is comprised and arranged to be connected with hydraulic coupling means on the tool and hydraulic line means. The object of the invention is, among other things, to reduce the number of requisite lines in the hydraulic line means. According to the invention, the tool holder comprises furthermore valve means provided with switching means arranged to connect the hydraulic line means either to the hydraulic cylinder means or to the hydraulic coupling means of the tool holder. Thereby, the same hydraulic line means may be used for the locking i 5 function and the tool. The invention also relates to a crane provided with such a tool holder as well as use of the tool holder.