Contact-sensing probe

A device for mounting a stylus in position-determining apparatus wherein said device and an object are movable relative to each other for providing a signal when said stylus engages said object thereby indicating the position thereof, said device comprising:

• a fixed member;
• a movable member to which said stylus is connectable and which is supportable on said fixed member at three locations arranged in a plane and at the three corners of a triangle, said members respectively defining at each said location, a supported element and a supporting element confronting the supported element in a direction perpedincular to said plane, at a first said location one of said elements having surface means defining an axisymmetric recess covergent in said direction and the other element being engageable with said recess;
• at a second said location one of said elements having second surface means defining a pair of surfaces convergent in said direction and the other element being engageable with said pair of surfaces;
• one of the second surface means and the element engageable therewith being shaped to define an axis extending in a direction including the first and second locations;
• at the third said location one of the elements having third surface means defining a flat surface parallel to said plane and the other element being engageable with said flat surface, bias means for urging the movable member into contact with the fixed member;
• and
• said first, second and third surface means co-operating under the force of the bias means to locate the movable member in a positive rest position on the fixed member, the movable member being removable from the rest position in opposition to the bias means when a force is applied to said stylus and being retrunable to the rest position by said means and surface means on cessation of said force.