Filling machine for food products in cans, particularly of the type with product density control

Abstract

A filling machine for food products in cans, particularly of the type with product density control, comprising a supporting frame which forms a chamber and a feeding tunnel which is adapted to convey a food product into the chamber that is provided with a plunger which can move along the chamber, along a predefined compression direction; the chamber being provided with an expulsion piston configured to move transversely with respect to the compression direction for the expulsion of at least one preset shape in the direction of a station for canning the food product; a motor being provided which is associated with the plunger for a movement along the compression direction; and elements for measuring the density of the food product compressed in the chamber in order to control the driving torque of the motor as a function of the achievement of a predetermined density value.

1 - 12 . (canceled) 
     
     
         13 . A filling machine for food products in cans, particularly of the type with product density control, comprising a supporting frame which forms a chamber and a feeding tunnel which is adapted to convey a food product into said chamber; said chamber being provided with a plunger which can move along said chamber, along a predefined compression direction, between a bottom dead center position (PMI), in which said chamber is free from said plunger in order to feed said food product into said chamber, and a top dead center position (PMS), in which said plunger occupies at least partially said chamber for a compression of said food product into at least one preset shape; said chamber being provided with at least one expulsion piston which is configured to move transversely with respect to said compression direction for an expulsion of said at least one preset shape in a direction of a station for canning said food product; motor means being further provided which are associated with said plunger for a movement thereof along said compression direction; and further comprising means for measuring a density of said food product compressed in said chamber in order to control a driving torque of said motor means as a function of an achievement of a predetermined density value. 
     
     
         14 . The filling machine according to  claim 13 , wherein said means for measuring the density of said food product compressed in said chamber comprise means for measuring a driving torque of said motor means. 
     
     
         15 . The filling machine according to  claim 13 , wherein said motor means comprise a mechatronic system constituted by a control unit, a rotary servo motor of the brushless type provided with an encoder, and a speed reduction unit. 
     
     
         16 . The filling machine according to  claim 13 , wherein said motor means are associated with said plunger by virtue of a first rod-and-crank mechanism. 
     
     
         17 . The filling machine according to  claim 13 , wherein said feeding tunnel comprises a plurality of conveyor belts which are oriented parallel to each other so as to form a passage channel interposed between said conveyor belts; said conveyor belts comprising an upper conveyor belt, a lower conveyor belt, and two lateral conveyor belts. 
     
     
         18 . The filling machine according to  claim 13 , wherein said feeding tunnel comprises a plurality of skimming elements which are arranged at an inlet of said chamber for an optimum conveyance of said food product into said chamber. 
     
     
         19 . The filling machine according to  claim 13 , wherein said feeding tunnel has a longitudinal extension that is substantially perpendicular to said compression direction. 
     
     
         20 . The filling machine according to  claim 16 , wherein said chamber is delimited, on an opposite side with respect to said plunger proximate to said top dead center, by an abutment element which is contoured, on a side directed toward an inside of said chamber, with a geometric profile which reproduces in negative form a portion of said at least one preset shape. 
     
     
         21 . The filling machine according to  claim 20 , wherein said abutment element is shaped to form at least two predefined shapes; said at least one expulsion piston comprising at least two expulsion pistons which correspond to said geometric profile of said abutment element. 
     
     
         22 . The filling machine according to  claim 20 , further comprising adjustment means for adjusting a position of said abutment element along said compression direction. 
     
     
         23 . The filling machine according to  claim 21 , wherein said adjustment means comprise a servomotor which is associated with said abutment element by means of a second rod-and-crank mechanism in a cascade arrangement with respect to a guiding and adjustment device. 
     
     
         24 . A method for the filling of food products in metallic boxes, cans, comprising the steps of:
 feeding a food product to a chamber provided with a plunger which is configured to move along said chamber, along a predefined compression direction, between a bottom dead center position (PMI), in which said chamber is free from said plunger in order to feed said food product into said chamber, and a top dead center position (PMS), in which said plunger occupies at least partially said chamber for a compression of said food product into at least one preset shape;   setting up a predetermined density value of said food product;   compressing said food product by means of said plunger;   measuring a density of said food product compressed by said plunger in said chamber;   actively controlling, during the compression of each single compression cycle, a driving torque of the motor means adapted to move said plunger, said driving torque being controlled by detecting a density of the food product compressed and adjusting said driving torque in order to achieve said predetermined density value of said food product;   upon achieving said predetermined density value of said food product stopping a stroke of said piston in a position that corresponds to said predetermined density value, avoiding compressing further said food product.