| 摘要 |
<p>The stepping drive mechanism comprises a toothed wheel (5) and an operating member which advances the toothed wheel each time by one tooth, the plane wherein said member moves being perpendicular to the plane of the toothed wheel (5). The operating member is a twin arm pawl (3) which is mounted pivoting on a slide (1) which has a reciprocating motion, the pawl presenting a tooth guiding surface (4) which is inclined with respect to the displacement direction of the slide (1) and which passes from one inclined position to the other upon each switching cycle.</p> |
