Plastics sheet slitting machine with parallel blades - has quickly adjusted fixed grooves to suit slight changes in blade spacings

摘要

A cutting or slitting unit for dividing a plastics sheet into a large number of parallel strips comprises a beam or shaft, on which a large number of cutting blades are mounted with spacers between them; these blades co-operate with grooves of a fixed, helically grooved drum; this drum is constituted of a number of separate tubes all of equal dia. and having an external helical thread of pitch equal to the spacing of the cutting blades; these threads thus constitute grooves between them, which are pref. of trapezoidal or rectangular cross-section. Where a large number of very narrow (e.g., a few mm.) strips are to be cut from a wide plastics sheet, the number of blades and corresp. grooves can amt. to several hundred; the removal and replacement time when blades become worn is considerably reduced, in that only a relatively short length of the fixed drum needs to be assembled accurately opposite to the blades the next section of drum can be adjusted in its axial groove position by a slight relative rotation clock-wise or counter clock-wise relative to the first; i.e., the threads are not necessarily continuous around the entire drum. In this way the long fixed drum can be rapidly assembled to suit the spacing of a continuous row of many blades.