| 摘要 |
<p>Apparatus for controlling lateral alignment of a web (12) moving along a path, said apparatus including at least one steering roller (22) for supporting said web and mounted for turning about an axis (Ac) perpendicular to the plane of the span of said web approaching said steering roller by sensing means (66, 68) for sensing the lateral position of an edge of said web relative to a reference plane as said web moves along such path, characterized by said sensing means producing a first signal when said edge is positioned at a first predetermined location (X1) relative to such reference plane and producing a second signal when said edge is positioned at a second predetermined location (X2) relative to such reference plane spaced from said first location and by turning means (64) for turning said steering roller about said axis in either of two opposite directions corresponding to said first and second signals for moving said edge toward said first or second location respectively as said web moves along such path.</p> |
