Shock-resistant device for a measuring machine

A shock-resistant device for a measuring machine comprising a body, a measurement rod movable within the body and at least one measurement probe connected to the measurement rod and intended to contact an element of a part to be measured under the pressure of a return spring, characterized by the fact that it is composed of two members in engagement, in the form of a bolt and a nut with reversible relative rotation and axial displacement, one of which (21, 40, 55) is fastened to the body (1, 25, 46) of the instrument and is immoveable at least axially with respect to it, while the other (20, 39, 56) is connected to the measurement rod (4, 27, 45) of the instrument so as to be displaced and driven axially by the latter, a single one of these two elements being moveable in rotation with respect to the body to which it is attached and the frictional force developed by the relative rotation of these two elements in engagement, upon displacement of the measurement rod within the body, being so determined as to yield at least to the pressure of the return spring (7, 34, 54) of the measurement machine.