Patent GB-696546-A (GB)
Title: Method and apparatus for wrapping
IPC: B65B9/02
Filed: 1950-02-20
Abstract: 696,546. Wrapping-machines. WINGFOOT CORPORATION. Feb. 20, 1950 (Oct. 22, 1949], No. 4323/50. Class 94(i) In a wrapping-machine, a web of heat-sealable wrapping material is advanced on the surface of a conveyer, an article to be wrapped is placed thereon, a second web is positioned over the article, the webs are joined together by a reciprocating, resilient presser member and the wrapped article and webs advanced to a cut-off position where the wrapped article is separated by cutting the webs wholly within the boundaries thereof. As shown in Figs. 9 and 10, the article 1 to be wrapped is deposited on film of wrapping material 13 which passes from a supply roll over the surface of an endless conveyer comprising a series of buckets 6 interconnected by pins 9 formed with projections 20, Fig. 12, which penetrate the wrapping material. Each bucket is provided with a replaceable sponge rubber liner 7 formed with a recess 8 similar in shape to the article 1. The ends of the pins 9 are adapted to engage in recesses 12 in star wheels 10 and 11 which are rotated intermittently to advance the article and film. The latter is heated to render it stretchable by a horizontally-reciprocable element 14 operated in synchronism with the conveyer. A second film of wrapping material 18 passes from a supply roll 17 over a tensioning roller 21 and bars 32 extending between rings 30 mounted for rotation on rollers 34, Fig. 5, carried by plates 35 movable in vertical guides on the machine frame 24. The bars carry projections, similar to those on the pins 9, which penetrate the film, and their ends are bifurcated for engagement with rollers 51 on the ends of the pins 9, whereby movement of the conveyer to the right causes rotation of the rings so that the two films of wrapping material are fed into superposed relationship with the article between them. The film 18 is heated by an element 19 which is reciprocated vertically in synchronism with the conveyer. The heated films are sealed together about the article by a reciprocable sponge-rubber member 36 which is formed with a recess 37 and located in a metal holder 38 secured to a channel 39 mounted for vertical movement within the rings 30 on guides carried by the frame 24. During the sealing operation, air is evacuated from the package by nozzles 110, Fig. 5, one at each side of the machine, which are mounted for horizontal reciprocation in spring-loaded guides 109 and are connected by pipes 111 to a vacuum pump provided with a relief valve. The nozzles normally ride between the two superposed films being fed through the machine and are moved inwardly to the position shown in Fig. 5 just before the member 36 is lowered to effect the sealing. The member 36 seals the films together about the article and nozzles, the latter are withdrawn after the air has been exhausted and the member 36 then completes the sealing operation. On the next movement of the conveyer, the wrapped article is moved clear of the member 36 and due to the resiliency of the liner 7 the united layers of wrapping material are raised clear of the surface of the conveyer as shown in Fig. 9. An electrically-heated wire 46, having a shape similar to that of the article and carried by air oscillatable arm 42, is then lowered to sever the wrapped article from the united layers, and on the next movement of the conveyer the wrapped article falls on to a delivery conveyer 5. The waste wrapping material is wound up on a roll 50. In a modification, Figs. 16 and 17 (not shown) suitable for wrapping flat articles, the liners 7 are replaced by plates denning a rectangular recess which receives the wire 46 at the cut-off position. The presser member-is Hollowed out so that it only contacts the film 18 outside the area of the article, and the heaters may be modified so that the films are heated only over the areas which are to be pressed together. Specifications 619,113, 696,561 and 696,562 are referred to.