Patent ID: 8096194

Claim:
Transducer for measuring preload and torque of a screw, comprising a first cylindrical sensor element and a second cylindrical sensor element that are connected together and to an element with a threaded hole for tightening the screw to be subjected to measuring, the two sensor elements being arranged for measuring respectively torque applied to a head of the screw and a pull between the screw and the element with a threaded hole, characterized in that the transducer comprises a hollow body made as a monobloc with two annular measuring zones which are spaced apart axially and form part of said first and second sensor elements the two annular measuring zones of said hollow body having a wall with reduced thickness with respective torque and force load-cell sensors and being separated from an intermediate annular zone of the hollow body which has a wall with a greater thickness than the annular measuring zones where said greater thickness makes said intermediate annular zone substantially stiff for the operating torque of the transducer and in said hollow body there is internally provided a seat for non-rotating coupling with the threaded-hole element in a part of which the screw introduced axially through an end of the hollow body is tightened.