Sealing and Transversal Cutting Device for Loose Product Packaging Systems

Abstract

Herein described is a device for sealing and cutting film in packaging systems for loose product, comprising transversal rotating shafts synchronised with each other, to which a couple of pincers is engaged comprising sealing and cutting means. Said pincers are connected to mechanisms comprising lower prestretching plates and upper prestretching plates forced in predefined positions by springs that react to a set almost circular path that brings the two pincers into contact one in front of the other so that the upper ones hold back the loose product and the lower ones carry out a prestretching of the film, so as to prepare the film for sealing and cutting without any interpositioning of loose product.

1 . Device for sealing and cutting film in packaging systems for loose product, comprising rotating transversal shafts ( 1 - 2 ) synchronised with each other, to which a couple of pincers ( 32 ,  34 ) is engaged comprising sealing and cutting means ( 15 ), characterised in that said pincers ( 32 ,  34 ) are connected to mechanisms ( 6 ,  7 ) comprising lower prestretching plates ( 28 ) and upper prestretching plates ( 29 ) forced in predefined positions by springs ( 10 ,  11 ) that react to a set almost circular path that brings the two pincers ( 32 ,  34 ) into contact one in front of the other so that the upper ones hold back the loose product ( 101 ) and the lower ones carry out a prestretching of the film ( 100 ), so as to prepare the film ( 100 ) for sealing and cutting without any interposition of loose product.  
   
   
       2 . Device according to  claim 1 , characterised in that said springs ( 10 ,  11 ) are operatively interposed between transversal bodies ( 3 ,  4 ) of said pincers ( 32 ,  34 ) and lower and upper mobile bodies ( 8 - 9 ) supporting said prestretching plates ( 28 ,  29 ).  
   
   
       3 . Device according to  claim 1 , characterised in that it comprises a cam ( 50 ) for guiding the prestretching with which small wheels ( 51 ) belonging to the upper mobile bodies ( 9 ) interact enabling the opening of the upper plate ( 29 ).  
   
   
       4 . Device according to  claim 1 , characterised in that said shafts ( 1 ,  2 ) are connected to a motion transmission ( 24 ).  
   
   
       5 . Device according to  claim 1 , characterised in that said pincers ( 32 ,  34 ) present a fissure ( 31 ,  33 ) transversal to the film.  
   
   
       6 . Device according to  claim 5 , characterised in that said cutting means consist of a mobile blade ( 15 ) inside the fissure ( 31 ) of one ( 32 ) of said pincers ( 32 ,  34 ).  
   
   
       7 . Device according to  claim 1 , characterised in that it comprises a cam ( 16 ) for guiding the blade ( 15 ) interacting in certain angular positions with a body ( 18 ) to which the blade ( 15 ) is engaged.  
   
   
       8 . Device according to  claim 1 , characterised in that said lower plate ( 28 ) has a prestretching foot ( 30 ).  
   
   
       9 . Device according to  claim 1 , characterised in that it comprises rigid connection shims ( 5 ) between the rotating shafts ( 1 ,  2 ) and the transversal support bodies ( 3 ,  4 ).