| 摘要 |
<p>Press tool used for pressing cruciform openings into the head of screws, also known as Phillips head screws, has a double conical head with cruciform cross section. The press tool head (33) has a cylindrical shank (21) and the head section (22). This section has four ribs and its cross section is cruciform. The enclosing envelope of this ribbed section is conical and the tool nose has also a conical shape of a greater included angle than the base section. The base section is enclosed by a cone with straight sides. The lateral face (24) of each conical rib has trapezoidal shape and the nose faces have triangular shape. The two conical sections are a symmetrical to each other in relation to the bisector of the adjacent angles between the adjacent press tool ribs.</p> |
