Patent GB-1127490-A (GB)
Title: Continuous package forming machine
Inventor: EBERMAN AUGUSTUS HARVEY
IPC: B65B9/04
Filed: 1966-11-29
Abstract: 1,127,490. Packaging machines; conveyers. OSCAR MAYER & CO. Inc. 29 Nov., 1966, No. 53394/66. Headings B8A and B8C. Apparatus for packaging articles between opposed webs of self-adhesive film includes continuously moving die plate members, the upper of which draw an upper film into depressions to shape it and the lower of which are covered by the other film upon which is deposited the articles, the upper and lower plates coming together to form vacuum chambers. These, after partial sealing of the films about the articles and vacuumizing, are opened to atmosphere to cause both films to adhere completely and seal the packages. Gas may, however, be introduced prior to sealing. The machine includes cutting means which travel with the films during their operation. Supercooled film is used and the machine includes heating means to produce crystallization and thus destroy adhesiveness after package sealing. Packages.-The films 305 and 24 also enclose a stiffener sheet 113, Figs. 4, 5 on which, e.g. slices of bacon 112 are assembled prior to their being placed on the lower film. Contents feeding (Figs. 3, 5, 7).-The lower web 24 extends across die members 20 joined as a continuously moving chain. Feed members, each comprising a horizontal table 30 move in an endless path 29 passing obliquely over the web. The tables are capable of vertical reciprocation. The slices and sheet are loaded, e.g. by hand on to the tables and as the latter move across the web, spring loaded stripper fingers 93 slide through grooves in the table surface to deposit each load on the web. The speed of the tables is such that the velocity of the loads is the same as that of the web 24 in the direction of movement of the latter. Vacuumizing and sealing (Figs. 3, 29).-The upper web is drawn over a chain of upper die members 118 into the depressions 174 of which, it is pulled by suction. It is additionally held by needles 182 on either side of each plate against which it is pressed by rollers (308), Figs. 14, 16 (not shown) operating on the upper run of the chain. Each die 118 includes ports controlled by cam rail operated valves 130- 134. The lower die members likewise have cam operated valves 270, 272. Provision is made (not used in the embodiment described) for feeding neutral gas in through one of the ports. As the upper and lower die plates come together, a sealed chamber is formed about the webs and each article, but due to the fact that the lower web is narrower than the upper and that " fences " 264 on the lower die plate prevent contact between the webs, the webs only seal together transversely. Vacuum having been maintained in the depressions 174, vacuum is now applied to draw out air from between the webs via ports 261a and valves 270, 272. Next, space 174 is opened to atmosphere so that the upper web is pressed round the contents and seals itself to the lower web inwardly of the fences 264. Package separation and ejection (Figs. 3, 29, 32).-As the upper dies leave the joined packages, they pass beneath radiant heater means (not detailed) to destroy the self-adhesive characteristics. They are held during this operation and subsequent cutting, by vacuum applied round the periphery of an ejector plate 249 in each die 20. The cutting means comprises discs 432 mounted on a head 345 arranged for vertical reciprocation on a carriage 450. The carriage moves horizontally at the speed of the webs during cutting and returns, as the discs are raised clear of the packages, after cutting. Each of the four discs is carried by an element 366 attached to chains 413, 414 moved intermittently to carry each disc round part of a rectangular path with rounded corners. A feeler roller 388, see also Fig. 36 (not shown), runs over the packages and if contents are missing, prevents operation of the cutters by maintaining them clear of the webs. The roller also operates a numerical counter. Finally, the separated packages are raised by the ejectors 249, vacuum having been relinquished, and transferred to endless discharge belts 492. The scrap web is wound up on a roller 488. Reference has been directed by the Comptroller to Specifications 965,031, 965,032 and 965,034.