| 摘要 |
<p>A system for sensing and indicating the centering of a sheet continuously fed through a machine includes a pair of laterally spaced apart sensing arms biased into contact with the opposite edges of the sheet as the sheet is being fed through the machine. Separate transducers responsive to movement of the sensing arms produce electrical signals representing the actual position of each edge of the sheet. The signals from both transducers are compared with input signals representing the known centered position of the sheet to provide an output indicating the magnitude and direction of the deviation from center independently of variations in the width of the sheet or any lateral movement of the sheet through the machine. An alarm is activated when the sheet deviates from its centered position by more than a selected amount.</p> |
