| 摘要 |
Apparatus for severing a running web at different intervals to subdivide the web into sections of desired length has two advancing rolls which transport the web lengthwise at a constant speed toward the nip of two rotary cutters having blades which sever the web in predetermined angular positions of the cutters. The cutters are driven in opposite directions by a stepping motor which receives stepping signals at a first frequency when the blades are about to sever and while the blades sever the web to thereby rotate the cutters at the speed of the web, and at any one of different second frequencies in other angular positions of the cutters. The system which transmits stepping signals has an exchangeable indicia-bearing disk which is driven by the advancing rolls through the medium of a variable-speed transmission or through one of several transmissions having different ratios. The indicia on the disk include a first group which is detected by a signal generator while the blades are about to sever and while the blades sever the web, and a second group of indicia which are detected by the signal generator during intervals between successive movements of blades to the cutting positions. By replacing the disk with a disk having different groups of first and second indicia and by changing the ratio or the transmission or by replacing the transmission with a transmission having a different ratio, the operator can change the distance between successive cuts.
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