| 摘要 |
<p>A film trimming device places opposing wheel rollers on spaced-apart axes of rotation on respective separate shafts therefor, with radially outward circumscribing faces thereof in contact and moving in a common direction at the point of contact, with a blade's cutting edge directed in a direction substantially opposite to that common direction and pressed against correspondlateral side faces of the contacting rollers at the point of contact of the rollers, with tape guiding and channeling structures shaped and positioned to regulate adjustably the amount of tape margin extending beyond the lateral side faces of the rollers when guided onto the radially outward circumscribing face of one of the rollers before reaching the cutting edge and for channeling the trimmed tape to a take-off point, the blade being normally biased into the cutting position and being retractable therefrom for permitting first drawing a portion of fed tape to and beyond the cutting point before gradually returning the cutting edge to press against the edge of the tape being drawn past, such that the cutting edge initially slices into the edge of the margin and upon the cutting edge reaching its position against the lateral side faces at which point the cutting edge trims the margin portion extending beyond the lateral side faces, at least one of the rollers being free-floating laterally to and fro along its axis of rotation, and there being an anti-bias structure pressing on the opposite lateral side face of the free-floating roller in order to hold it in a contacting relationship with the cutting edge.</p> |
