| 摘要 |
923,029. Perforating machines. PRODUKTIONS-SERVICE A.B. Aug. 31, 1960 [Aug. 31, 1959], No. 30067/60. Class 31 (2). A perforating machine for producing tearoff perforations in material 24 comprises a tape-like blank 18 provided with notches 21 and mounted in a roller 4 the edge 23 of the blank 18 being engageable by the members 10 of a roller 9, the blank 18 having an outer knife-like portion 20 of material softer than that of the members 10 so that when the rollers 4, 9 are rotated either before or during a perforating operation, the edge 23 is worn off by the members 10 until the outer edge of the portion 20 conforms to the outline shape of the members 10. |
