Patent ID: 7392711

Claim:
An insertable strain gauge spanner comprising; a spanner body 1 having a rod body and a driving head insertable into the rod body; the rod body having a handle and an inserting opening at one upper end of the rod body; the inserting opening can receive the driving head; the rod body being installed with a strain gauge; the inserting opening being in contact with the strain gauge; thereby the twisting force from the driving head can be transferred to a sensing end of the strain gauge; the twisting force being displayed in a window of the strain gauge; and the driving head having an inserting end a shape corresponding to that of the inserting opening; and the orientation of the driving head with respect to the rod body is adjustable by adjusting the orientation of the inserting end with respect to the inserting opening so as to avoid a great twisting force is transferred to the strain gauge from the driving head wherein a connecting rod is installed in the rod body; a portion at an upper end of the connecting rod near the inserting opening is interacted with the driving head inserted into the inserting opening; and a lower end of the connecting rod is formed as an inclined surface for transferring a react force from the driving head to the strain gauge to indicate the twisting force wherein the inserting opening and inserting end have a cruciform shape.