System for measurement of force with directionally orientated strain gauges

In a gauge device for indication of a load on an object by detecting bending stresses of said object, comprising:

• a shaft (1) fixable at both ends,
• at least one gauge unit (2) disposed on an outer surface of the shaft (1);
• electrical connection lines (3) coupled to the at least one gauge unit (2) and running out through the end of the shaft;
• the improvement wherein:
• the shaft (1) is releasably insertable in a hole in an object which is subjected to a load, said hole having a bottom and side walls which are subjected to a load to cause bending movements of said side walls, a clearance being provided between the portion of the shaft intermediate its ends and the side walls of the hole, the end of the shaft inserted first into the hole being the inner end and the opposite end being the outer end;
• and
• fixing means is provided at the inner and outer ends (16, 17, respectively) of the shaft to releasably fix said inner and outer shaft ends both axially and radially relative to the walls of the hole, said fixing means at the inner end of the shaft comprising threads (16) which are arranged to engage with threads provided in the bottom of the hole, said fixing means at the outer end of the shaft including means fixedly coupling the outer end of the shaft to the walls of the hole so that the shaft, like a part unseparated from the walls of the hole, accompanies said walls in their bending movements, which are due to a load on the walls of the hole.