| 摘要 |
A cutting device (10) having a pair of blades (12, 14) with V-shaped cutting edges (V12, V14) and a substantially V-shaped bend (Fig. 4c) causing the center of the blade (V12, V14) to deviate from a vertical plane. One blade is reciprocated relative to the other blade. The outer ends of each blade have sliding projections (12f, 12g, 14f, 14g) slidably engaging marginal portions of the outer surfaces of the other blade so that, as the blades move relative to one another, the cutting edges are drawn toward and cross-over one another during cutting, whereby the blades increasingly move away from the bent V-shape and toward a planar shape. The blade edges (12a, 12b, 14a, 14b) cut a web (A) from both outer edges toward the center of the cutting blades with the center portion of a member, such as a sheet, being cut last. The blades resume their V-shaped configuration when the blades are moved to the initial, open position. By limiting the stroke of the moving blade, the center portion of the sheet being cut remains uncut which is advantageous for certain applications. The blades are set into blade support frames (17, 17') which hold one end of the blades in a fixed position while the opposite ends of the blades are permitted to slide to accommodate movement of one end of the blades as they are elongated due to movement from the bent toward the flat configuration. The cutting edges of the blades may be modified to make a complete cut (12a, 12b, 14a, 14b), a partially perforated and partial cut (Fig. 8d) and a perforated cut, across the item being cut (Fig. 7d). The blades may be driven by a variety of driving devices such as solenoids (26), motor driven cams (27) and permanent magnets (32a, 32b). <IMAGE> |
