| 摘要 |
A machine for folding cuts or sheets of paper or the like particularly cuts for envelopes or the like, has an adjustable roller device carrying, for example, a knife for preliminary cutting or a series of suction openings. The roller device can be adjusted in relation to its driving gear wheel to a predetermined angle by a remotely controlled adjusting device. The angularly adjustable part of the roller device is operatively connected with the driving gear wheel in the operative position of the roller device. When this connection is interrupted and the gear wheel stands still the adjusting device adjusts the roller relatively to the gear wheel to the extent of a predetermined angle which is set by an actuating potentiometer. The invention is particularly characterized by the provision of an actual value potentiometer and slip rings fixed to one of the parts which are rotatable relatively to each other, the potentiometer having a ring-shaped resistance. This provides an electrical connection of this potentiometer with the electrical circuit for adjusting the roller device. The slider of this potentiometer is coupled with the other one of the parts rotatable relatively to each other in such manner that when the part of the roller device which is to be adjusted relatively to its gear wheel, is rotated by a predetermined angle, there is a rotation by the same angle between the slides of this potentiometer and its ring-shaped resistance. When the angular adjustment of the roller set by the actuating potentiometer has been completed, the actual value potentiometer will stop automatically the remotely controlled adjusting device by means of a value comparing device known per se.
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