| 摘要 |
837,247. Producing folded rims on plastic containers. KERKE, K., VAN DE., and KERKE, D. VAN DE, March 13, 1958 [March 21, 1957], No. 8070/58. Class 87(2). [Also in Group XVII] The upper rim of a plastic container, e.g. of polyvinyl chloride, has a horizontal flange on which a lid of similar material is heat sealed, the flange then being folded back with simultaneous cooling while it is still soft. The container resting on a table 29 is movable verti-. cally through a supporting ring 31 for the flange and above the table are a vertically movable ring or electrode 8 and a cooling ring 15 the inner diameter of which is smaller than the outer diameter of the container flange. In operation, the cooling ring is movable downwards until it rests upon the stop ring 32 on supporting ring 31, the sealing ring 8 being such that it moves on through the cooling ring in order to seal the container. The upward movement of the sealing and cooling rings, when the former is again above the latter but before the latter has left the supporting ring, causes the release of table 29 which has been held against the action of a spring 23 by a ball-lock (not shown) and the container with the flange which is still soft snaps into the cooling ring. This cooling ring consists of a number of segments 16 which are forced radially outwards against an elastic member as the flange of the container is folded back. The elastic member may consist of latex foam or plastic foam, or may be formed by an elastic cooling pipe which then at the same time effects the cooling of the segments. |
