| 摘要 |
1,232,633. Moulding corrugated tubing. DART INDUSTRIES Inc. 8 May, 1968 [8 May, 1967], No. 21879/68. Heading B5A. Apparatus for the continuous production of corrugated tubing by blow-forming extruded tubing is essentially similar to that described in Specification 1,124,071 with the addition of a pair of vertically reciprocable knives 40, Figs. 1 and 5, and associated tube clamps 16, so arranged that predetermined lengths of tubing are cut-off without the release of the blowforming pressure within the tubing upstream of the knives. Each clamp 16 comprises a fixed half 20 and a half 26 retractable by means of a fluid-actuated cylinder 60. The halves 20, 26 have cavities 22, 24 which may or may not be internally configured in correspondence with the blown tube. If the cavities are smooth the tubing is subjected to a compressive force. Each knife 40 passes through slots in the top and bottom of its associated clamp 16, see dotted line (50) position, Fig. 4 (not reproduced), and the faces of the knife blade seal the cut ends of the tubing. In operation, Fig. 5, knife 40 at station C is lowered followed by lowering of knife 40 at station B. With the latter knife remaining lowered, knife 40 may be raised at station C with associated clamp 16 being opened. The cut end of the tubing is removed from this clamp and the upstream portion of the tubing is looped and placed therein, Fig. 7 (not shown). The knife 40 at station C is now lowered and that at station B raised with release of associated clamp 16 and removal of tube length 66. The process is continued in a similar manner, Figs. 8 and 9 (not shown). |
