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(11) | EP 0 741 014 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | An infeed mechanism for a paper press or the like |
| (57) In presses for printing on a continuous web of paper, various units disposed in series
are driven in synchronisation by a line-shaft, and an infeed friction cylinder has
been driven independently by an electric motor so controlled by sensors as to modulate
the rotation ratio between the line-shaft and the friction cylinder to control lengthwise
stretching of the web, and also control the position or phase of the web when it is
re-inserted for subsequent printing. Accuracy has been limited by the independent
friction cylinder drive and also by transmission errors in the sensor drives. Superior
accuracy is achieved by driving the friction cylinder 50 directly from the line-shaft
54 by way of a phase-shifting gearbox 72 in series with a bevel gearbox 74, the phase-shifting
gearbox additionally being driven by an electric servo-motor 102 controlled by a first
position encoder 98 driven directly by the line-shaft and a second position encoder
100 driven directly by the friction cylinder so as to modulate the rotation ratio,
and also controlled by marks printed on the web 38 and by a reference point on a gear
driven directly by the line-shaft so as to synchronise the position of the web. |