Device for tightening a nut on a fastening pin of a nuclear reactor guiding tube

摘要

A tightening wrench (5) carrying a measuring cell (8) freely mounted in the hollow part (4) of a wrench (5) and adapted to bear against an end of the pin (2) subjected to the pretension. A detector emitting and receiving ultrasounds (21) disposed inside the measuring cell (8) is made to bear against the end of the pin (2) by a spring (25) interposed between the cell (8) and the detector (21). The cell (8) itself bears against the end of the pin (2) through the action of a leaf spring (9) carried by the wrench (5).