GB996580A - Packaging machine - Google Patents

Abstract

996,580. Wrapping-machines. W. R. GRACE & CO. June 4, 1962 [June 6, 1961], No. 21548/62. Heading B8C. A wrapping machine of the kind in which two webs are joined to form a sheet in the path of an article to be wrapped, forward movement of the article causing the webs to embrace the article, and are then sealed and severed behind the article, the seal joining them to form a new sheet, has positive web feed control means responsive to the tension imposed on the webs by the article. The machine is fully adjustable for various article sizes and may include means (not shown) to heat shrink the wrappers about the articles. Articles from a hopper (Fig. 1, not shown) having an outlet control plate 20 are held in check on a conveyer 14 by a stop controlled by a pneumatic motor 26. At the starting of the machine by pressing a switch, conveyers 14, 31, 60 are set in motion and the stop lowered, permitting an article 21 to advance against the joined webs 48. The article contacts a switch 104 to release the stop so that it may rise again behind it for checking the following article. The webs pass from braked rolls 45, 46 round driving rollers 50, tensioning rollers 51 and guide rollers 52 and during initial movement of the article and webs the rollers 51 are moved (to the left, as shown) against their loading springs until one of them opens a switch 96. This releases the roll brakes and commences the driving of the rollers 50 to feed film from the rolls. The partially wrapped article or indicia on the web now activate photo-electric means (Fig. 1, not shown), whereby the conveyers 14, 31, 60 are halted and a frame 40 caused to descend. The frame includes a transverse sealing member 42 co-operating with a fixed element 43 which presses the webs together behind the article and severs and joins them again. As they are released by the members 42, 43, the rollers 51 are permitted to return to the right, straightening the web sheet across the wrapping path and allowing the switch 96 to close. The feed rollers 50 are thus halted and the rolls braked. At the same time the frame 40, in rising, operates a switch starting the conveyers again and lowering the stop to release the next article. The cycle now repeats and the partially wrapped article has its sides enclosed while the next transverse seal is made behind the following article. For this, the frame 40 carries sealing and severing bars 68 cooperating with bars 67, Fig. 7. Rollers 65, 66, the former being driven, discharge the protruding waste margins through apertures 72 in the machine casing. Alternatively, belts may do this (Fig. 8, not shown). If desired, the side sealing members may be made to hinge clear when it is desired only to place a band round one or a group of articles. Specification 996,581 is referred to.