Machine for forming and wrapping stacks of products

Abstract

In a machine for forming and wrapping stacks of products, a stacking plate, having a number of radial seats for relative stacks of products, rotates in steps about a respective axis to feed each seat along an annular path extending through a loading station for loading individual products, a reject station, and an unloading station for unloading stacks; the reject station being controlled by a sensor activated selectively by counter-pushers, each of which is moved along a relative seat by the individual products fed successively through an inlet of the seat at the loading station.

1 ) A machine for forming and wrapping stacks ( 31 ) of products ( 2   a ), the machine comprising a stacking plate ( 26 ) rotating in steps about a respective axis ( 27 ); a loading station ( 25 ) and an unloading station ( 33 ) for said stacking plate ( 26 ); and a number of radial seats ( 30 ,  30   a ) formed on said stacking plate ( 26 ), each said seat ( 30 ;  30   a ) receiving a relative said stack ( 31 ); and the machine being characterized by also comprising a reject station ( 32 ) interposed between said loading and unloading stations ( 25 ,  33 ), each said seat ( 30 ;  30   a ) having an inlet ( 29 ) movable with said stacking plate ( 26 ) along an annular path (P) extending about said axis ( 27 ) and through said loading, reject, and unloading stations ( 25 ,  32 ,  33 ); feed means ( 22 ) for feeding said products ( 2   a ) successively to said inlet ( 29 ) at said loading station ( 25 ); first and second unloading means ( 66 ,  34 ) for successively unloading said stacks ( 31 ) at said reject station ( 32 ) and said unloading station ( 33 ) respectively; sensor means ( 70 ) for controlling said first unloading means ( 66 ); and counter-pusher means ( 51 ) fitted movably inside each said seat ( 30 ;  30   a ), and moved along the seat ( 30 ;  30   a ), into an enabling posit enabling said sensor means ( 70 ), by said products ( 2   a ) fed successively to the relative said inlet ( 29 ) at said loading station ( 25 ).  
   
   
       2 ) A machine as claimed  claim 1 , wherein each said seat ( 30 ) is coaxial with another said seat ( 30   a ) to form a pair of coaxial seats ( 30 ,  30   a ); the seats ( 30 ,  30   a ) in each said pair having common said counter-pusher means ( 51 ).  
   
   
       3 ) A machine as claimed in  claim 1 , wherein seats ( 30 ,  30   a ) are formed along slots ( 46 ) arranged in coaxial pairs; the slots ( 46 ) in each pair ( 47 ) of eating with each other and extending along a diameter of said stacking plate ( 26 );  10  the counter-pusher means ( 51 ) of the seats ( 30 ,  30   a ) formed in two coaxial said slots ( 46 ) being common to both said seats ( 30 ,  30   a ), and comprising a single diametrical rod ( 52 ) having a first and a second end head ( 53 ), each of which is mounted to slide, inside a respective said seat ( 30 ;  30   a ), between an outer limit position in which the head ( 53 ) is located at said inlet ( 29 ) of the relative said seat ( 30 ;  30   a ), and an inner end said head ( 53 ) is located at an inner end of the relative said seat ( 30 ;  30   a ).  
   
   
       4 ) A machine as claimed in  claim 3 , and also comprising brake means ( 56 ) fitted to each said rod ( 52 ) to control slide of the rod ( 52 ) along the relative said pair ( 47 ) of coaxial slots ( 46 ).  
   
   
       5 ) A machine as brake means ( 56 ) are located at a central portion of said stacking plate ( 26 ).  
   
   
       6 ) A machine as claimed in  claim 3 , wherein stop means ( 50 ) are housed inside each slot ( 46 ) in each pair of ( 47 ) of coaxial slots ( 46 ) to define the relative said seats ( 30 ,  30   a ), and which cooperate with the relative said head ( 53 ) when the head ( 53 ) is in the inner limit position.  
   
   
       7 ) A machine as claimed in  claim 1 , wherein each said seat ( 30 ;  30   a ) has a central longitudinal bottom strip ( 54 ) defining, along the seat ( 30 ;  30   a ), two longitudinal passages ( 55 ) on opposite sides of said strip ( 54 ); each of said first and second unloading means ( 66 ,  34 ) comprising a fork-shaped ejecting member ( 66 ;  34 ), which is movable back and forth, in a direction parallel to said axis ( 27 ), through said two passages ( 55 ) to expel the respective said stack ( 31 ) from each said seat ( 30 ;  30   a ) at said reject station ( 32 ) and said unloading station ( 33 ) respectively.  
   
   
       8 ) A machine as claimed in one of the foregoing  claim 1 , wherein said sensor means ( 70 ) are located along said annular path (P) and diametrically opposite said loading station ( 25 ); said unloading station ( 33 ) being located along said annular path (P), between said loading station ( 25 ) and said sensor means ( 70 ).  
   
   
       9 ) A machine as claimed in one of the foregoing  claim 1 , wherein said sensor means ( 70 ) comprise a proximity sensor ( 71 ).  
   
   
       10 ) A machine as claimed in  claim 10 , wherein said proximity sensor ( 71 ) is an inductive type.  
   
   
       11 ) A machine as claimed in  claim 1 , wherein push means ( 64 ) are provided at said reject station ( 32 ) to expel a said stack ( 31 ) radially from said stacking plate ( 26 ); and conveying means ( 65 ) are provided to receive the expelled said stack ( 31 ).  
   
   
       12 ) A machine as claimed in  claim 11 , wherein said push means ( 64 ) are pneumatic push means.