| 摘要 |
A head for the linear dimension checking of pieces in machine tools or measuring machines with a support structure (1), a movable arm-set (4) including an arm (6) carrying a feeler (8) for contacting the piece (37) to be checked, a spring (17) arranged between the support structure and the movable arm-set, a first annular surface (19) fixed to the support structure, a second annular surface (18) fixed to the movable arm-set and urged by the spring into contact with the first annular surface and an electric detecting device. The detecting device includes a ring (16) made of electrically resistive material that defines the first annular surface and another ring (13) made of electrically resistive material that defines the second annular surface, a circuit (21) for applying a difference of potential across two points (22, 23) of the first ring and another circuit (30) for detecting the difference of potential across two points (24, 25) of the other ring. |
