| 摘要 |
A programmer comprising a cam unit which can be rotated manually in a first direction by a control shaft 23 able to occupy, under the action of a pawl device comprising a spring, any one of several equidistant stable angular stop positions spaced apart by the angular value of one step, before passing on each occasion through a limiting unstable intermediate angular position, after which this shaft is brought in a resilient manner by the pawl device towards the following stable angular stop position. A motor and drive transmission system are able, when controlled, to rotate the cam unit step by step in said first direction. The cam unit is connected to rotate with the control shaft, with an angular clearance less than the angle through which the shaft travels, between any one of its stable angular stop positions and the limiting unstable intermediate angular position which follows. |
