Patent GB-1296252-A (GB)
IPC: B65B41/14
Filed: 1970-01-20
Abstract: 1296252 Packaging machines INTERCAN SA 20 Jan 1970 [21 Jan 1969] 2817/70 Heading B8C A packaging machine comprises a roller 1 supporting a thermoplastics film 2, a mechanism for guiding and conveying the edges of the film 2 whilst the film is supported on chains (not shown), a station 8 for heating the film 2, a station 14 for forming containers 15 from the film 2 which containers 15 are filled at a station 16, and a station 17 at which a 'cover sheet 9 is welded to the containers 15 and the completed packages are severed from the film 2. Film feed mechanism (Fig. 2, not shown).- This mechanism comprises a series of clips mounted on endless chains 9 which extend the entire length of the film. Each clip comprises a stop secured to its conveyer chain 9 and having an upper face which abuts the lower face of the film 2, and by a movable stop spring biased against the upper faces of the fixed stop. Cams (not shown in Fig. 2) act on the movable stop to open the clip, and are located before the heating station 8 and after the station 17. Heating station (Fig. 3, not shown).-The heating station 8 comprises two superposed but staggered rows of bare metal strip resistors which are transverse to the film 2 and form a heating plate pivoted to a shaft 27 to enable differential heating of the film 2. Container forming station 14.-At the forming station a piston (105, Fig. 10) is lowered into a mould (103) so as to partially form a container. Compressed air is then supplied to the space around the piston (105) so as to force the film against the walls of the mould. Welding and cutting station.- The cover sheet 19 is fed from a roll 18 to a position overlying the filled containers 15 via guide rollers 20 (a-d). The station 17 comprises two staggered rows 28a, 28b of welding and cutting out tools 295, 30S and 29D, 30D (Fig. 4). Each welding tool comprises an upper part 29Ss or 30Ss mounted in a recess 33 in a block 34 secured to a vertically reciprocable support 32, the welding tool being mounted on a rod 31 and being biased away from the support 32 and against a stop 37 on the rod 31 by a spring 36. The upper part 29Ss (30Ss ) is provided with a heating circuit 35 and has a marginal rib 38 adapted to press the covering sheet 19 against a container 15. The lower part 29Si (30Si) of each welding tool is secured to a vertically reciprocable frame 39 the travel of which is at least equal to the height of a container 15, and the upper face 40 of the lower part 29Sc (30Sc), is adapted to abut the rib 38 of the upperpart 29Ss (30Ss). The end cutting tool also has an upper part 29Ds (30Ds) which is constituted by the lower edge 41 or a recess 33 in the block 34, and a lower part produced by the upper edge 42 of the outer wall of the lower part 29Si (30Si) of a welding tool. The lower edge 41a of the front wall of a recess 33 is recessed with respect to the other walls theresituation. A cooling circuit 44 is provided in the block 34. The upper parts 30Ds of the cutting tools in the second row 30 are bent outwardly in order to avoid recutting those containers cut out by the first row tools 29Ds. At the start of operation of the station 17 a row of containers 15 is held on the first row 28a of tools and the cover sheet 19 is welded to every second container in the row by the welding tools 29S, and at the same time the lower parts 29Si of the welding tools enter the recesses 33 to partially cut every second finished package from the sheet 2. After this operation, the film 2 is advanced to bring a fresh row of containers 15 into the station 17 and advance the first row of containers into the second row 28b of tools. Those containers which were not sealed during the first operation are now sealed by the tools 30S, and the containers are completely cut from the film 2.