| 摘要 |
An electromechanical speed variator for apparatus having a device suitable to be rotated at two or more speeds different from one another, comprising a first electric drive motor for directly rotating said device at a first speed; a second electric drive motor for indirectly rotating said device at a second speed; a drive wheel connected to the shaft of one of said motors and a friction wheel idly rotably carried by a moving support between a first inoperative position remote from said drive wheel and a second operative position, thereat contacting said drive wheel and respectively the shaft of said other electric drive motor; and control means comprising an electromagnet, and return spring means acting on the moving support of the friction wheel to move the latter to either of its two said positions. |
