| 摘要 |
The present invention relates to a device for, as a consequence of a drive member 22 having been switched on, rotating a sleeve 5 on a tube 8 at a variable, regulated speed, the said sleeve 5 preferably being able to support a gate or the like. Upon being switched on, the drive member 22 actuates a valve 24, which admits a pressure medium so that the sleeve 5 is rotated in two guide grooves 13, 14, configured such that the rotary motion of the sleeve 5 is first slow, then faster and finally slow again. When the drive member 22 is switched off, the sleeve 5, through the action of the valve 24, returns automatically to its original position with the same motional pattern. <IMAGE> |
