| 摘要 |
1. Device for controlling the simultaneous translation of a plurality of elements at different speeds, comprising a screw (V), with at least two threadings having different pitches (P1 ), (P2 ), on which at least two successive bolts of corresponding pitches (E1 ), (E2 ) are mounted for movement, characterized in that the threads of the said two screw threadings are flat threads and are mutually overlapping so that the threads of one of the threadings cross the threads of the other threading of same winding direction but different pitch ; and in that the external surface of the screw formed by the top portion of the flat threads has a cylindrical envelope of constant cross-section from one end to the other. |
