| 摘要 |
<p>In a preferred embodiment, a wheel-like blade structure shaped substantially as a disk having a substantially flat circumscribing periphery with a notch therein forming the blade, and with each of opposite ends of the disk extending axially in substantially conical shapes and being biased in an upward blade position, having handle structure for rotating the disk in a downwardly blade-cutting direction against a biasing spring which spring simultaneously biases a flat horizontally positioned plate having a central hole therein in which the disk is mounted for suitable rotation and for movement of the blade downwardly in flush alignment with the forward inner edge of the hole in order to effect a scissor-type cutting action, with there being shoulders extending in opposite directions from the notch defining the blade, the shoulders serving as aligning shoulders for a linear edge of a microfilm jacket which when aligned therewith extends through the blade-notch between the blade and the top edge of the cutting portion of the plate such that when the blade is brought downwardly a notch is cut into the edge of the microfilm jacket, and there being a slidable flat horizontally positioned plate for sliding to and fro laterally in front of the aligning shoulders and in front of the cutting blade, on which the microfilm jacket is flatly mountable with there being included on the slidable microfilm mount a plurality of designations in series of different notching positions relative to a seating position for the microfilm jacket on the horizontal laterally to and fro slidable plate, and including a spring-biased key for snap-in releasable engagement of the slidable mounting plate in each of the designated notching positions so as to intermittently hold the slidable mounting plate in a fixed position during a notching operation.</p> |
