Drive mechanism of a working part of a device for linear, fast and slow strokes

摘要

The mechanism has a helical connection type screw-nut system whose drive screw (2) is driven by a motor (5) and a nut (3) is integrated in translation with a work unit e.g. cylinder rod (1). The screw has an axis that is offset parallely with respect to an axis of the nut by a value (e) corresponding to difference between diameters of the screw and the nut such that trapezoidal threads of the screw and the nut cooperate with each other. A squeezer (10) blocks rotation of the nut when needed such that traveling time of the unit is less than that when the nut is freely rotated around the screw.