Device for vacuum packaging, particularly of food products

Abstract

A packaging device, particularly for manually or automatically packaging trays containing food products or technical materials which can be inserted, by means of a loading platform, between longitudinally folded parts of a single-folded film and comprising elements for thermal bonding or heat-sealing for sealing, and at least one nozzle for producing a vacuum and/or for introducing the gas or mixture, and a vacuum chamber. The single-folded film is fixed and the vacuum chamber is movable and comprises at least one movable presser arranged above the single-folded film. The presser is forced on top of the tray and is provided with elements adapted to convey the streams of air and/or gas. The return of air into the vacuum chamber occurs by means of a series of holes provided between a transverse heat-sealing bar and the wall of the vacuum chamber that is parallel thereto.

1 - 29 . (canceled) 
     
     
         30 . A packaging device, particularly for manually or automatically packaging trays containing food products or technical materials which can be inserted, by means of a loading platform, between longitudinally folded parts of a single-folded film and comprising means for thermal bonding or heat-sealing for sealing, and at least one nozzle for producing a vacuum and/or introducing the gas or mixture, and a vacuum chamber, wherein said single-folded film is fixed and said vacuum chamber is movable transversely to the direction of insertion of said trays and comprises at least one presser, movable over said single-folded film, which is forced on top of said trays and is provided with means adapted to convey the streams of air and/or gas, the return of air into said vacuum chamber occurring by means of a series of holes provided between a transverse heat-sealing bar, which constitutes said thermal bonding means, and the wall of said vacuum chamber that is parallel thereto. 
     
     
         31 . The device according to  claim 30 , wherein said vacuum chamber is a bell-shaped vacuum chamber constituted by a lower container and by a closeable upper lid, bands or gaskets adapted for airtightness being provided perimetrically to said container and to said lid, said single-folded film having a first longitudinal side which is closed and a second longitudinal side which is open, said single-folded film being kept open by the presence of a pair of supports between which said loading platform, motorized or movable on means, is interposed, said pair of supports being movable mutually closer by means of a handwheel adapted to adjust their mutual position. 
     
     
         32 . The device according to  claim 30 , further comprising at least one means adapted to draw said single-folded film, said means being constituted by a motor which actuates a roller which cooperates with a complementary roller, said single-folded film being made to pass between said rollers, said motor, said roller and said complementary roller being supported by an arm, which protrudes from a fixed footing, with which said pair of supports, said handwheel and said loading platform are also associated. 
     
     
         33 . The device according to  claim 30 , wherein said bell-shaped vacuum chamber is moved along an axis that is transverse to the direction of advancement of said single-folded film, which coincides with the direction of insertion of a tray that is adapted to contain said technical materials or food products. 
     
     
         34 . The device according to  claim 31 , wherein said bell-shaped vacuum chamber is arranged inside a frame constituted by a pair of uprights and by a pair of crossmembers, said crossmembers supporting respectively a pair of first cylinders adapted to move said upper lid and a guide adapted to allow the sliding of said frame at a complementary guide which is integral with said footing. 
     
     
         35 . The device according to  claim 31 , wherein a raised shelf is provided inside said lower container, which is adjacent to the end of said loading platform, and is adapted to support said tray inside said bell-shaped vacuum chamber, at said upper lid there being arranged internally at least one presser, which is movable by means of a pair of second cylinders, which are externally jointly connected to said upper lid in a region that is adjacent to said upper crossmember. 
     
     
         36 . The device according to  claim 31 , further comprising a first heat-sealing bar, which is L-shaped and arranged within said bell-shaped vacuum chamber, with one side adjacent to an inlet of the food product; a cutting blade being arranged laterally adjacent to said first heat-sealing bar, a pair of third cylinders and a pair of fourth cylinders being arranged at an outer surface of said upper lid and being arranged along mutually perpendicular directions and being adapted to actuate a second heat-sealing bar, which is arranged mirror-symmetrically with respect to said first heat-sealing bar. 
     
     
         37 . The device according to  claim 35 , wherein said presser is provided with means adapted to convey the streams of air and/or gas, said means being constituted by a plurality of ribs which protrude from it in the direction of said tray and are arranged transversely to the direction of advancement of said single-folded film, said ribs being made of rubber, so as to be able to adhere at the edges of said tray, defining channels adapted to allow the passage of the air and/or gas. 
     
     
         38 . The device according to  claim 35 , wherein said presser moves jointly with the opening and closing of said bell-shaped vacuum chamber. 
     
     
         39 . The device according to  claim 31 , further comprising means adapted to convey the streams of air and/or gas, said means being constituted by a nozzle, which is integral with the bell-shaped vacuum chamber and is accommodated hermetically within a box-like appendage provided in two half-shells which protrude laterally to said bell-shaped vacuum chamber along an axis which is perpendicular to the axis of advancement of said single-folded film. 
     
     
         40 . The device according to  claim 31 , further comprising a plurality of holes for the return of air into said bell-shaped vacuum chamber, to return it to atmospheric pressure following the heat-sealing of a package, said plurality of holes being provided between said first heat-sealing bar and the adjacent wall of said bell-shaped vacuum chamber. 
     
     
         41 . The device according to  claim 34 , wherein it is controlled by mechanical and/or electronic means for predetermining a desired position of said frame in one or more preset points, so that for each type of package it is possible to set, by means of a computer, the position of said frame automatically as the package that arrives on said loading platform varies. 
     
     
         42 . The device according to  claim 34 , wherein said frame is also movable transversely with respect to the direction of advancement of said single-folded film. 
     
     
         43 . The device according to  claim 30 , comprising a loading platform that supports a single-folded film that defines at least two parts which are folded longitudinally to accommodate trays that contain food products and technical materials, thermal bonding or heat-sealing means being comprised which are adapted to seal said folded parts of said single-folded film peripherally with respect to said trays, and at least one nozzle being comprised which is adapted to provide a vacuum and/or adapted to introduce a gas or a mixture in a vacuum chamber that accommodates said trays inserted between said folded parts of said single-folded film, so that said single-folded film and said vacuum chamber are movable with respect to each other transversely to the direction of insertion of said trays in said vacuum chamber, wherein said thermal bonding or heat-sealing means comprise a plurality of independent heat-sealing bars, at least one of them being transverse and at least one of them being longitudinal with respect to the direction of advancement of said single-folded film. 
     
     
         44 . The device according to  claim 43 , wherein said vacuum chamber is bell-shaped and is provided by a lower container and by an upper lid, which can be closed onto said container, bands or gaskets for airtightness being interposed perimetrically between said container and said lid. 
     
     
         45 . The device according to  claim 43 , further comprising a pair of supports, which can be moved mutually closer by means of a handwheel adapted to adjust their mutual position in order to open said single-folded film, said loading platform being interposed between said pair of supports, and said single-folded film having a first longitudinal side which is closed and a second longitudinal side which is open. 
     
     
         46 . The device according to  claim 45 , further comprising at least motor means which are adapted to draw said single-folded film and actuate a roller that cooperates with a complementary roller, said single-folded film being passed between said rollers, said motor means, said roller and said complementary roller being supported by an arm that protrudes from a fixed footing with which said pair of supports, said handwheel and said loading platform are associated. 
     
     
         47 . The device according to  claim 43 , wherein said vacuum chamber is arranged within a frame constituted by a pair of uprights and by a pair of crossmembers, said crossmembers supporting respectively a pair of first cylinders adapted to move said lid and a guide adapted to allow the sliding of said frame at a guide that is integral with said footing. 
     
     
         48 . The device according to  claim 43 , wherein said vacuum chamber can move along an axis which is substantially transverse to the direction of advancement of said single-folded film, said substantially transverse axis coinciding with the direction of insertion of said trays. 
     
     
         49 . The device according to  claim 43 , further comprising at least one presser, which can move above said single-folded film, can engage said trays in an upper region, and is provided with means adapted to convey the streams of air and/or gas. 
     
     
         50 . The device according to  claim 49 , wherein said means adapted to convey the streams of air and/or gas comprise a plurality of ribs which protrude in the direction of said tray and are arranged transversely to the direction of advancement of said single-folded film, said ribs being made of rubber in order to adhere at the edges of said tray so as to define a plurality of channels adapted to allow the passage of air and/or gas. 
     
     
         51 . The device according to  claim 49 , wherein inside said container, adjacent to the end of said loading platform, there is a raised shelf, which is adapted to support said tray inside said vacuum chamber, said presser being arranged internally at said lid and being movable by means of a pair of second cylinders, which are externally jointly connected to said lid in a region that is adjacent to said crossmember. 
     
     
         52 . The device according to  claim 49 , wherein said presser can move jointly with the opening and closing of said vacuum chamber. 
     
     
         53 . The device according to  claim 43 , further comprising at least one nozzle which is integrally connected to said vacuum chamber, said at least one nozzle being accommodated hermetically within a box-like appendage that is provided in two half-shells that protrude laterally from said vacuum chamber along an axis which is perpendicular to the axis of advancement of said single-folded film. 
     
     
         54 . The device according to  claim 51 , further comprising a first transverse heat-sealing bar, which is arranged in proximity to an inlet of said vacuum chamber, a cutting blade being laterally adjacent to said first transverse heat-sealing bar, at the outer surface of said lid there being a pair of third cylinders adapted to actuate a second transverse heat-sealing bar, which is arranged mirror-symmetrically with respect to said first transverse heat-sealing bar. 
     
     
         55 . The device according to  claim 45 , further comprising a first longitudinal heat-sealing bar, which is arranged inside said vacuum chamber so as to correspond to said open longitudinal side of said single-folded film of the food product, a cutting blade being arranged laterally adjacent to said first longitudinal heat-sealing bar, at the outer surface of said lid there being a pair of fourth cylinders adapted to actuate a second longitudinal heat-sealing bar, which is arranged mirror-symmetrically with respect to said first longitudinal heat-sealing bar. 
     
     
         56 . The device according to  claim 54 , further comprising a plurality of holes for the return of the air into said vacuum chamber in order to return it to atmospheric pressure after the heat-sealing of a package, said plurality of holes being provided between said first transverse heat-sealing bar and the adjacent wall of said bell-shaped vacuum chamber. 
     
     
         57 . The device according to  claim 47 , wherein it is controlled by mechanical and/or electronic means for predetermining a desired position of said frame in one or more preset points, so that for each type of package it is possible to set, by means of a computer, the arrangement of said frame automatically as the package that arrives on said loading platform varies. 
     
     
         58 . The device according to  claim 47 , wherein said frame can also move transversely with respect to the direction of advancement of said single-folded film.