| 摘要 |
<p>This mechanism comprises a series of rings 25a, 25b, 25c, 25d, which are mounted freely in rotation on the axis 5 of the rotary element 1, and each of which comprises a stop 26a, 26b, 26c, 26d extending over a fraction of its circumference and projecting axially over a distance enabling it to bear against one side or the opposite side, in the circumferential direction, of the stop of a contiguous ring in one or other of two relative angular positions of the said rings between which the latter are freely movable in rotation relative to one another, and also a stop 29 for driving the rings and a stop 30 for stopping the rings carried by the said rotary element 1 and by the fixed support 6 respectively and adapted for each to cooperate with the stop for the ring which is adjacent to them. <IMAGE></p> |
