Patent ID: 7640785

Claim:
A device for test running of power nut runners, comprising: a main body with a nut, a screw engaging the nut and having a nut runner engaging head, a clamping element engaged by the screw head, and a spring unit disposed between the clamping element and the main body and arranged to be compressed at rotation of the screw in its tightening direction, a one-way clutch between the nut and the main body for locking the nut against rotation relative to the main body at rotation of the screw in its tightening direction and permitting rotation of the nut relative to the main body at rotation of the screw in its loosening direction, a friction brake between the nut and the main body for preventing rotation of-the nut relative to the main body at rotation of the screw in its loosening direction, and a lock element secured to the screw and arranged to positively engage the nut in a position of the screw where the spring unit is no longer compressed, thereby accomplishing a nut rotating force overruling said friction brake.