| 摘要 |
<p>A control system is established wherein, when there is a flow of continuous web material (2), an identification phase is provided by increasing the torque signal to a pull roll motor (13) until slippage between the pull roll (12) and continuous web is created at a breakaway torque point, the value of which is measurable. The pull roll motor is then caused to be driven by a signal which creates a motor torque output which is of a value less than the breakaway torque point. Thus, no slippage can occur. As the motor is driven at the lower torque value, a calibration phase is entered wherein an encoder output of the pull roll is properly equated with that of a measuring wheel (9), this phase occuring at a time when there can be no slip between the web-roll interface. The identification-calibration process can be repeated as often as desired. The control system further includes the ability to cause acceleration of the pull roll after the web has been severed upstream to thereby accelerate the tail or downstream portion of the severed discontinuous web until a desired gap is created for use in a slitting device (6). At this point, which is subsequent to the identification-calibration phases, the control returns the motor input to the lower torque value.</p> |
