Packaging machine in which a product is packaged by wrapping with a film of packaging material

Abstract

A machine for packaging a product ( 2 ) in a wrapper forms the wrapper by wrapping with a film ( 8 ) of packaging material, supplied in the form of a continuous web from an apparatus ( 4 ) for supplying film ( 8 ) which can move relative to the product ( 2 ) in such a way that it revolves around the product ( 2 ) and translates longitudinally relative to the product ( 2 ). The machine ( 1 ) comprises mechanical means ( 10, 5, 14 ) for synchronising the speed at which the film ( 8 ) is supplied with the speed at which the apparatus ( 4 ) revolves around the product.

1 - 13 . (canceled) 
   
   
       14 . A machine for packaging a product ( 2 ) in a wrapper formed by wrapping the product ( 2 ) with a film ( 8 ) of packaging material, said wrapping being achieved using a supplying apparatus ( 4 ) which supplies a continuous web of said film ( 8 ) and which can move, relative to the product ( 2 ), in such a way that it revolves around the product ( 2 ) and translates longitudinally relative to the product ( 2 ), the machine ( 1 ) comprising mechanical synchronising means ( 10 ,  5 ,  14 ), provided with at least a motion input shaft ( 6 ;  31 ), for synchronising the speed at which the film ( 8 ) is supplied with at least the apparatus ( 4 ) revolving speed around the product ( 2 ) and speed detecting means ( 9 ,  10 ,  5 ,  14 ) which are directly integrated with the mechanical synchronising means ( 10 ,  5 ,  14 ), the machine ( 1 ) being characterised in that said speed detecting means ( 9 ,  10 ,  5 ,  14 ) for detecting the instantaneous speed of rotation of the apparatus ( 4 ) comprise at least one fixed race ( 9 ) supported by the machine and at least one corresponding wheel ( 10 ) connected to the input shaft ( 6 ;  31 ) and held in contact with the race ( 9 ), the revolution of the apparatus ( 4 ) around the product ( 2 ) to be packaged causing the wheel ( 10 ) to roll on the fixed race ( 9 ) and consequent corresponding driving of mechanical synchronising means ( 10 ,  5 ,  14 ). 
   
   
       15 . The machine according to  claim 14 , wherein the mechanical synchronising means ( 10 ,  5 ,  14 ) comprise a mechanical variator ( 5 ), supported by the movable supplying apparatus ( 4 ), moved by the motion input shaft ( 6 ;  31 ) and provided with a motion output shaft ( 7 ); the input shaft ( 6 ;  31 ) rotating with an angular speed correlated with the instantaneous peripheral speed of the revolving motion of the supplying apparatus ( 4 ) around the product ( 2 ), the output shaft ( 7 ) in contrast driving a unit ( 3 ) for unwinding the film ( 8 ) in such a way that the speed at which the film ( 8 ) is supplied is suitably correlated with the movable apparatus ( 4 ) revolving speed. 
   
   
       16 . The machine according to  claim 15 , wherein said apparatus ( 4 ) is made to revolve around the product by drive means ( 24 ;  24   m,    25 ,  26 ,  26   t ), the machine ( 1 ) comprising means ( 9 ,  10 ,  5 ,  14 ) for deriving the energy for supplying the film ( 8 ) of packaging material from the apparatus ( 4 ) drive means ( 24 ). 
   
   
       17 . The machine according to  claim 14 , wherein it comprises friction means ( 27 ) which are operatively inserted between the wheel ( 10 ) and the race ( 9 ). 
   
   
       18 . The machine according to  claim 14 , further comprising thrust means ( 11 ) for forcing said at least one wheel ( 10 ) into contact with said corresponding race ( 9 ). 
   
   
       19 . The machine according to  claim 18 , wherein the thrust means ( 11 ) include the centrifugal force to which the mass of the variator ( 5 ) is subjected due to the revolving speed of the apparatus ( 4 ) around the product ( 2 ). 
   
   
       20 . The machine according to  claim 18 , wherein the thrust means include spring elements ( 11 ) which are designed to press said at least one wheel ( 10 ) against the race ( 9 ). 
   
   
       21 . The machine according to  claim 15 , further comprising a support ( 12 ) for the variator ( 5 ) which at a first connecting point pivots around a rotation pin ( 13 ) which is offset relative to a joining line ideally passing through the apparatus ( 4 ) centre of rotation and through the variator ( 5 ) centre of mass, and which at a second connecting point rests against the race ( 9 ) by means of said one or each wheel ( 10 ). 
   
   
       22 . The machine according to  claim 15 , further comprising a belt drive ( 14 ) positioned between the variator ( 5 ) output shaft ( 7 ) and a shaft ( 6 ) of a unit ( 3 ) for unwinding film ( 8 ) from the apparatus ( 4 ). 
   
   
       23 . The machine according to  claim 21 , wherein the support ( 12 ) comprises a plate ( 33 ) having two half-surfaces ( 28 ,  29 ) being monolithic and converging with each other at an angle, one of the half-surfaces ( 28 ,  29 ) supporting a variator ( 5 ) casing ( 30 ), the other half-surface ( 28 ,  29 ) supporting the variator ( 5 ) motion input shaft ( 7 ). 
   
   
       24 . The machine according to  claim 15 , wherein the variator ( 5 ) has means for selecting the gear ratio which comprise an adjusting mechanism ( 34 ) that is motor-driven and can be remote controlled.