Patent ID: 8286361

Claim:
An apparatus for checking the diameter of a cylindrical part in orbital motion about a geometrical axis in a numerical control grinding machine, said apparatus comprising: a reference device for cooperating with the cylindrical part in orbital motion and defining a checking condition of said apparatus; a measuring device movable with the reference device; a support device for movably supporting the reference device and the measuring device, the support device including coupling elements with a first coupling element rotatable about a first axis of rotation parallel to said geometrical axis, and a second coupling element coupled to said first coupling element and rotatable with respect to said first coupling element about a second axis of rotation parallel to said geometrical axis; a limiting element for limiting rotational displacements of the second coupling element with respect to the first coupling element; and a control device for enabling the apparatus to displace in an automatic way from a rest position to the checking condition, and vice versa.