| 摘要 |
1,075,588. Forming sheet material. O. W. CHRISTENSSON. Sept. 10, 1965 [Oct. 22, 1964], No. 38702/65. Heading B5A. [Also in Division B8] A plastics cover 71, to be heat-drawn on to a plastics-lined container 40, is first heated while remote from the container. The package is supported on a raisable base 46 of a mould which slides within a fixed frame 56. At the stage at which the plastics cover 71 is applied to the top of the support and heated by means of an element 72, the base and mould are at their lowest positions as shown and a vacuum valve 69 is opened to evacuate the inside of the mould and support, thereby drawing the plastics cover partly into the evacuated space. Upon replacement of the heating element 72 by a mandrel (73), Fig. 6 (not shown) the package is raised in the mould under the action of cams (52, 164) to the position of Fig. 6 (not shown) and the mandrel (73) is then lowered to depress the heated cover to a level beneath the level of the edge of the package. Both mandrel and mould are cooled by a flow of coolant through duets (74, 75) and (44, 45). A set of packages may be sealed with a single plastics sheet by an array of such devices, the packages subsequently being separated by cutting away the intermediate parts of sheet between them. In a second embodiment, Fig. 8 (not shown), the heating means and container are separated horizontally. The plastics cover material is supplied in a sheet at (85<SP>11</SP>) to a turret device, which then turns so that the plastics material may be heated at a station (96). At a station (84<SP>11</SP>) the cover is applied to an array of packages, in a similar manner to that of the previous embodiment, and finally at station (95) the sealed packages are delivered on to an output conveyer (93). |
