| 摘要 |
<p>1,134,094. Automatic control of web feeds. N. WADDLETON (Spezialmeschinenfabrik Robert Giebeler K.G.) Oct.31, 1965, No.39972/65. Heading G3R. The speed of rollers 4 feeding a web of material 1 through a printing and/or perforating machine 6 is controlled by adjustments of a differential gear 16 in response to the phase difference between two electrical signals, one corresponding to the operation of a marker device and the other from a detector spaced from the marker. As shown, a perforator 6 acts as the marker, the perforations being detected photo-electrically at 8, but in an alternative system, Fig.2 (not shown) printed or magnetic marks are applied immediately after the feed rolls and are detected before the perforator. The object is to ensure accurate spacing of the perforations or marks.</p> |
