| 摘要 |
<p>1,245,473. Perforating tubes. WAVIN N.V. 26 Aug., 1968 [1 Sept., 1967], No. 40641/68. Heading B3A. A device for making apertures in a corrugated plastic tube comprises a guide member 2, Fig. 1, for the tube 6 and a nut member rotatably mounted on bearings 3 inside said guide and carrying punches 8 reciprocable by a cam surface 10 to perforate the tube. In another embodiment, Fig. 3, a single punch 7 is provided and is actuated by a cam track 12 with which co-operates a projection 14 on the punch stem 8.</p> |
