US 3745742 A
Description (OCR text may contain errors)
United States Patent 1 Tartarini [451 .lluly 17,1973
[ MACHINE FOR VACUUM PACKAGING VARIOUS PRODUCTS, IN PARTICULAR FOR VACUUM PACKAGING FOOD PRODUCTS  Inventor: Cesare Tartarini, Via Colombo 9,
Zola Predosa, Italy  Filed: Sept. 7, 1971  Foreign Application Priority Data Sept. 11,l970' Italy .................L.........3546A/70  Appl. No.: 178,001
 US. Cl 53/112 A  Int. Cl B65b 31/02  Field or Search .i 53/112 A  References Cited UNITED STATES PATENTS 3,164,934 11/1965 7 Pancratz 53/112 A 3,061,984 11/1962 Mahaffy 53/112 A X Primary E xaminer-Travis S. McGehee Attorney-Guido Modiano and Albert Josif  ABSTRACT Vacuum packaging machine for food products, having conveyer means conveying a tape of moldable plastics to a vacuum forming station where depressions are vacuum formed in said tape for receiving the food prod ucts in such depressions. After a filling station where the food products are introduced into the depressions there is provided an evacuation closing and welding station, where filled depressions are covered by a tape of plastics material with the interposition of a suction month between the covering tape and one of the edges of the depressions, which evacuates the filled depressions while a welder welds the covering tape along the edges of the depression.
A cutting assembly separates afterwords the closed and evacuated depressions.
3 Claims, 4 Drawing Figures MACHINE FOR VACUUM PACKAGING VARIOUS PRODUCTS, IN PARTICULAR FOR VACUUM PACKAGING FOOD PRODUCTS BACKGROUND OF THE INVENTION The present invention relates to a machine for vacuum packaging various products, in particular for vacuum packaging food products. Machines for vacuum packaging presently available generally comprise a pneumatic chamber inside which the packages which have been previously partially prepared are evacuated. Because of the presence of the pneumatic chamber, which is always very heavy, the operational speed is necessarily very low because the operations relating to the chamber can only be carried out slowly. In machines comprising chambers there is a further limiting factor in the form of the dead spaces which always remain inside the chamber, and which give rise to the necessity of using pumps of very high capacity if evacuation times are to be reduced as low as possible.
A further grave disadvantage of chamber machines is that the product container must include a certain excess of the material used for forming the package, at least on part of its edges, so as to allow the members which grip the packages to operate and to facilitate the working of the components which separate the various packages.
Because of the high quality and consequent cost of the material used for the enclosures in vacuum packaging, this disadvantage results in a grave burden.
A further disadvantage of present machines for vacuum packaging is that they are not suitable for handling products whose shapes or dimensions are widely dispersed, in that they give rise to packages of particularly bad appearance because of wrinkles and curling, and also accentuate the former disadvantage of wide margins for ensuring a gripping surface.
SUMMARY OF THE INVENTION The object of the present invention is to provide a machine for vacuum packaging various products and in particular food products, which substantially obviates the aforementioned disadvantages of machines presently available, and which is able to work at high speed on products of any shape in that it comprises no appreciable dead space which might unduly lengthen working times.
This object is attained according to the invention by a machine for vacuum packaging various products and in particular food products, comprising means for supporting and guiding a pair of bands which approach each other longitudinally and fonn the packages, welding members lowered on to and raised from the bands for welding them transversally and longitudinally after introducing the products between them, and means for cutting the individual packages, characterised in that it comprises a suction port of flat structure disposed upstream of the transversal welding members and penetrating between the approaching portions of the bands welded along their lateral edges, means for driving said port with reciprocating motion parallel to the bands and cooperating with the means which operate the transversal welding members so as to withdraw the port during lowering of said welding members.
BRIEF DESCRIPTION OF THE DRAWING Further details of the invention will be more evident from the detailed description of one embodiment illustrated in the accompanying drawing in which:
FIG. 1 is a partially diagrammatical longitudinal view of the machine;
FIG. 2 shows on an enlarged scale the working members of the machine, predisposed for evacuating and welding the packages;
FIG. 3 is a plan view of the members shown in FIG. 2, and
FIG. 4 is a cross-section through the machine at the working zone of the longitudinal welders.
DESCRIPTION OF THE PREFERRED EMBODIMENT In the Figures the same component part or detail is in each case indicated by the same reference numeral, and they show the main assemblies of the machine, 1, 2, 3 and 4, namely the assembly for forming the band which will form the lower part of the package, the vacuum assembly, the organs for longitudinally separating the completed packages, and the cutting assembly for transversally cutting the packages respectively.
The assembly 1 forms on a band 5, which is unwound from a reel 6, depressions into which the product is introduced. The assembly 1 comprises a pair of members 7 and 8 between which the band 5 passes, the first constituting the forming die and the second a radiation heating complex which brings that section of band 5 opposite it to the plastic state.
The member 7 comprises substantially a body with a certain number of depressions or cavities (4 in the example illustrated) which produce that number of depressions in the band 5. The body 7 comprises a pair of lugs 9 pivoted to a shaft 10 about which said body can rotate through a certain angle by means of cams which co-operate with levers and connecting rods connected to the arm 9a. The cavities in the body 7 are connected by connectors 11 to a manifold 12 which is connected in its turn by a flexible pipe and valve means to the suction nozzle of a common vacuum pump. The member 8 comprises a hollow body with dimensions approximately corresponding to those of the body '7. It carries heating means and comprises lugs 13 by which it is pivoted to a shaft 14. The member 8 can also turn about the shaft 14 by means of cams co-operating with levers and connecting rods connected to the arm 13a.
The assembly I is completed by a mask 15 fixed to the frame of the machine, and a roller 16 idly pivoted on the shaft 10 for supporting the band 5. The mask 15 comprises a central opening corresponding to the working parts of the members 7 and 8, and protects those parts of the band 5 which are not to be shaped from thermal radiation. Following the assembly for forming the depressions there is a loading station for the product to be packaged in the depressions. Said loading station comprises a roller 18 about which the preformed band partially winds until it rests on a conveyor 19. The roller 18 for deviating the band is supported on a shaft 20 and comprises a tubular core 21 and a series of protuberances 22 fixed to said core which form seats for containing the depressions in the band 5, which is thus well supported and guided at all times.
The conveyor 19 comprises a band 23 supported by rollers 24 and 25, which moves in synchronism with the band comprising the depressions, i.e., it moves with intermittent motion with steps equal to the pitch of the depressions on the band and with an adjustable frequency. It should be noted that even at relatively low frequency a high production rate is possible, because the number of pieces produced in a unit of time is equal to said frequency multiplied by the number of depressions present in one transversal row of the band.
This number can be of any size within reasonable limits and in any case depends directly on the average size of products to be packaged. In the case shown the band, as stated, comprises four depressions disposed one beside another.
At the extremity of the band 23, i.e., in a position corresponding approximately with that of the roller 25, there is the vacuum assembly 2. Said vacuum assembly 2 consists in effect of two units strictly linked one with the other, one of which evacuates the packages, the other closing them by welding. The assembly 2 comprises a plate 26 which remains downstream of the conveyor l9 and slightly removed from it, incorporating a series of longitudinal ribs 27 (FIG. 4) which stand upwards and are of height equal to the maximum depth of the depressions formed in the band 5. These ribs are distanced apart so as to support the flat parts of the band which lie between adjacent depressions and the lateral edges of the band comprising the depressions. Said ribs act as guides for retaining the band transversally and as backing plates for the welding assemblies. In addition to said ribs 27 the assembly 2 comprises (FIGS. 2 and 3) two welders 28 and 29. The first of said welders, 28, comprises a working, i.e., heating, part 30 which on coming into contact with the material forming the package, welds it in the manner described hereinafter. Said working part 30 comprises a series of welding members 30a, 30b, 30c, 30d and 30e disposed longitudinally and of length equal to one package, and of which the two external members, 30a and 30e, are staggered in such a manner that they are slightly upstream of the others. The working parts of said first welder are supported by a support 31 rigid with a shaft 32 disposed above and transversal to the band, and supported by supports 33 and 34. An arm 35 is connected to said shaft external to the support 33, and is also connected to cams which move in cycle with the other members of the machine.
On said shaft 32 is mounted a tubular shaft 36 which supports a member 37 to which arms 38 are connected supporting the Working part 380 of the second welder, which operates transversal to the band and consequently extends between the two external members 300 and 30e of said first welder.
The arms 38 also support a presser 39 slightly down stream of the welder, consisting of a transversal bar 40 lowerly packed with resilient material. The bar 40 is provided with pivots 40a pointing upwards from its back which are inserted into suitable seats in the arms 38. Between the lower surfaces of said seats and the bar 40 there are springs 40b which maintain the bar pressed downwards.
A backing member 41 co-operates with the working part 380 of the transversal welder 29 and is supported by rods 42 which slide in seats 43 and are connected by levers to cams which cause them to rise and fall in cycle with said second welder, for letting the band 5 with depressions to pass forward.
The pressing bar 40 is permanently in contact with a band 44 which winds on a reel 45 and covers the band 5, and when welded to this latter forms the required package.
The band 44 winds partially on a roller 46 which is supported by arms 47 which support the evacuation aspirator described hereinafter.
The aspirator, 48, comprises a pipe 49 rigid with the ends of the arms 47 and a flexible pipe and suitable valve means for connecting it to a suction pump of conventional type.
The pipe 49 comprises a series of holes 50 which connect its interior with the interspace 51 of a suction port or mouth comprising a pair of plates 52 and 53 of width equal to the distance between the external members of the first welder 28, and which remain permanently between the bands 5 and 44.
The arms 47 are connected at their other ends to arms 54 of levers 55 which are operated by cams and which determine a forward and backward movement of said aspirator by the intermediate lever mechanism.
The aspirator rests on a member 56 disposed transversally over the band 5 as a bridge. More precisely, the member 56 consists of a pair of shoulders 56a and 56b and a laminar part 57 which joins them and on which the aspirator rests. The two said shoulders lowerly slide in vertical guides 57a and are driven by cam means cooperating with levers and connecting rods. The machine is completed by cutting assemblies 3 and 4, the first comprising a series of pairs of circular blades 60 and 61 which act longitudinally along the welding lines between adjacent depressions, whereas the second separates the various packages transversally. Said second assembly consists of a blade 62 co-operating with a fixed counter blade 63. The blade 62 is supported on a support 64 connected to the end of one arm of a rocking lever, the other arm of which is connected by connecting rods to a cam. The circular blades of the assembly 3, the roller 25 of the conveyor 19 and the roller 18 are connected to a source of rotary motion by means, for example a brake-friction clutch assembly, which provide an intermittent motion of amplitude variable according to the length of the packages.
Operation of the machine described is as follows. At the assembly 1, that part of the band 5 lying between the members 7 and 8 is heated and after having attained a plastic state predetermined for example by means of a timer, the interior of the member 7 is connected to the inlet of a pump and depressions are thus moulded in the band 5. After this moulding, the members 7 and 8 open, the first to allow the band to advance and the second so as not to heat parts which do not have to be heated. After the members 7 and 8 are opened the band 5 advances by a length equal to the pitch of the depressions. The 4 depressions so formed reach the conveyor 19 after a certain number of steps and during the time they remain on it the products to be packaged are introduced, into them.
As the band 5 advances along the machine, the series of depressions under consideration arrives at a certain point under the bridge member 56 which, during movement of the band, is raised. When the forward step of the band terminates the bridge member is lowered until it reaches the level shown in FIG. 2, and if the products introduced into the depressions are greater in height that the depth of the depressions, this movement lowers the products until they are brought in line with the edge of the depressions. After the bridge member 56 has been lowered, and with it the aspirator which rests on it, the lever 54 is operated by the corresponding cam and this initiates a backward movement of the aspirator 48 and hence also of the roller 46 on which the second band 44 winds, and simultaneously initiates the descent of the transversal welder 29 which as it acts on its backing member 41 transversally joins the two bands 5 and 44. When the transversal weld has been made the bands advance by one step and the depressions under consideration pass downstream of the backing member 41 and occupy their correct position on the plate 26. During said advancement the bridge member is in the raised position and the backing member 41 has descended. On termination of said advancement the backing member 41 rises and the bridge member descends, and the welder 28 with its welding members 30a, 30b, 30c, 30d and 302 joins the bands 5 and 44 along longitudinal lengths. When said welds are made the aspirator 48 is operated and acts on the group of depressions under consideration remaining partially within the external welding lines (FIG. 3) because of which its action is efficient and rapid even with pumps of relatively small capacity. After a certain time the aspirator while still working withdraws unitl it passes the line of the transversal welder 29 which descends and closes the group of packages. The presser 40 during this stage guarantees a good seal between the aspirator and band 44. During successive advancement of the bands 5 and 44, the longitudinal welders 28 complete the separation between the packages which are already closed to atmosphere, by completing the welding lines between one and the other, which is carried out by the end part of the longitudinal welders 30b, 30c and 30d. After a certain number of steps the packages under consideration arrive at the cutting assemblies 3 and 4 and are divided by these.
From the aforegoing description it is clear that with the machine according to the invention it is possible to treat products which are also sensitive to heat because of the small rise in temperature produced by welders in free air, which is impossible with chamber machines. It is also clear that if products of small thickness, such as sliced meats, are to be packaged, it is not necessary to premould the lower band 5, the action of the bridge member 56 being sufficient to make the aspirator and welders operate correctly.
1. A machine for vacuum packaging various products in particular food products including means for supporting and guiding a pair of bands which approach each other longitudinally and fold the packages, welding members lowered onto and raised from the bands for welding them transversally and longitudinally after introducing the products between them, and means for cutting the individual packages, a suction port of flat structure arranged upstream of the transversal welding member and penetrating between the approaching portions of the bands welded along their lateral edges, means for driving said port with reciprocating motion parallel to the bands and cooperating with the means which operate the transversal welding members so as to withdraw the suction port during lowering of said welding members, wherein according to the improvement, the machine further comprises an assembly for moulding, in at least one of the bands, depressions for receiving products, a plate provided below the longitudinal welding members for supporting the band provided with depressions, said plate comprising ribs having a hight substantially equal to that of the depressions and acting as backing members for said longitudinal welding members, a flat transversal member movable in a vertical plane behind said plate and acting in the raised position as a backing member for the transversal weld ing member, cam means for driving said welding members through levers and connecting rods.
2. A machine as claimed in claim 1 in which the longitudinal welding members and transversal welding members are supported on arms which project respectively from shaft supported on the upper part of the machine downstream of the working zone of the welding members and from a tubular shaft rotatably mounted coaxially of the former, the two said shafts also comprising arms on which cams act by way of interposed levers and connecting rods for driving the welders.
3. A machine as claimed in claim 1 in which said suction port comprises a pair of plates joined together so as to define a slot and of width equal to the distance be tween the external longitudinal welding members and which project tangentially from a tube having perforations in positions corresponding with said slot and connected by way of a flexible tube and valve means to a pump, and in which said tube is fixed to arms which in their turn are pivoted to the extremities of levers controlled through connected rods by cams so as to cause the forward and backward movement of the suction port, on said arms there being pivoted a roller on which the upper band of the package partially winds pressed against the upper plate of said suction port by a presser, said suction port laying on a bridge member transversally arranged above the band provided with depressions which slides in vertical guides and is driven vertically by cam means.