| 摘要 |
<p>The head comprises a casing (14) comprising three slides (15). In each slide is mounted a measurement key (18, 19) with an inclined base, radially displaced by the axial displacement of a measurement cone (22). Each key is held in contact with the measurement cone by a return spring (27). The base (21) of the [lacuna] axial cylindrical [lacuna] (20) of the casing (14) forms a body with a journal (25) with a micrometric screw (24) engaged in a threaded component (23) of the casing (14). In this way, the contact travel of the key on the measurement cone extends over a conical spiralled slope with constant increase and great length, resulting from the combined forward and rotational movements of the cone. This arrangement makes it possible to have a large angle at the apex of the cone, and therefore a large measurement capacity, without affecting sensitivity. <IMAGE></p> |
