| 摘要 |
The lifting unit (16) comprises a system of levers with at least two swinging arms (14). It subjects the roller (10) in the felt (12), to combined lift- and axial motion. Preferred features: The unit raises the roller on a circular path. Its implementation is that of a parallel crank mechanism. The swinging arms are fastened to a frame (18), with their other ends in bearings (20) supporting the roller during lifting. Arms are joined by a connecting section (22) spaced from their couplings (24) on the frame, at the lever ends near the frame. An actuating cylinder (30), screw jack or linear motor and/or other similar units provide the lift. Pivot axes are mutually parallel and horizontal. They are at right angles to the roller axis. The arms are attached to the frame at points spaced apart in the roller axis direction. Spacings between couplings to frame and those to the roller support, are equal. The swinging arms are constantly parallel to each other, whatever their angular position.
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