Method and apparatus for packaging objects of different types

Abstract

A method comprises the steps of:positioning a plurality of objects, having different dimensions to each other, on an infeed conveyor;delivering to an intermediate conveyor a flow of objects coming from the infeed conveyor and movable along an advancement direction;feeding a packaging unit with the objects coming from the intermediate conveyor, the packaging unit producing a plurality of packages, starting from a web of packaging material, each package containing one object.The method further comprises the step of checking if, in the flow of objects which advance along the intermediate conveyor, there are empty positions in which an object is missing. If an empty position is detected, there is provided filling the empty position by accelerating the objects which follow the empty position relative to the objects which precede the empty position. The intermediate conveyor comprises a plurality of conveyor belts arranged in sequence along the advancement direction. If the number of objects arriving on the intermediate conveyor in the unit of time is greater than or equal to a predetermined value, the production speed of the packaging unit is adjusted in such a way as to keep in the intermediate conveyor a predetermined average filling level.

1 . A method comprising the steps of:
 positioning a plurality of objects, having different dimensions to each other, on an infeed conveyor;   delivering to an intermediate conveyor a flow of objects coming from the infeed conveyor and movable along an advancement direction;   feeding a packaging unit with the objects coming from the intermediate conveyor, the packaging unit producing a plurality of packages, starting from a web of packaging material, each package containing one of said objects;   
       the method further comprising the step of checking if, in the flow of objects which advance along the intermediate conveyor, there are empty positions in which an object is missing and wherein, if an empty position is detected, there is provided filling the empty position by accelerating the objects which follow the empty position relative to the objects which precede the empty position, wherein the intermediate conveyor comprises a plurality of conveyor belts arranged in sequence along the advancement direction and wherein, if the number of objects arriving on the intermediate conveyor in the unit of time is greater than or equal to a predetermined value, the production speed of the packaging unit is adjusted in such a way as to keep in the intermediate conveyor a predetermined average filling level. 
     
     
         2 . The method according to  claim 1 , and further comprising the step of controlling the speed of the conveyor belts in such a way as to arrange the objects at a controlled distance from each other at the infeed of the packaging unit. 
     
     
         3 . The method according to  claim 1 , wherein the objects which follow the empty position are accelerated by increasing the speed of at least one conveyor belt which transports the objects which follow the empty position relative to the speed of at least one further conveyor belt which transports the objects which precede the empty position. 
     
     
         4 . The method according to  claim 1 , wherein the intermediate conveyor acts as a buffer in which a plurality of objects is temporarily accumulated while waiting to enter the packaging unit. 
     
     
         5 . The method according to  claim 1 , wherein the predetermined average filling level corresponds to a predetermined value of the ratio between a longitudinal dimension of the intermediate conveyor, measured in the advancement direction, occupied by objects which are positioned on the intermediate conveyor at a controlled mutual distance, and a total longitudinal dimension of the intermediate conveyor along the advancement direction available for receiving the objects. 
     
     
         6 . The method according to  claim 1 , wherein the predetermined average filling level corresponds to a predetermined average number of conveyor belts filled with the objects. 
     
     
         7 . The method according to  claim 6 , wherein the average filling level corresponds to half of the conveyor belts filled with the objects. 
     
     
         8 . The method according to  claim 1 , wherein the web of packaging material is fed to the packaging unit with a variable linear speed which is determined on the basis of the number of objects which the packaging unit receives from the intermediate conveyor and on the basis of the length of each object in the advancement direction. 
     
     
         9 . The method according to  claim 1 , wherein an applying device applies glue on the web of packaging material to generate at least one joint and to close a corresponding package and wherein, if the number of objects arriving on the intermediate conveyor in the unit of time is less than or equal to a predetermined value, the web of packaging material is fed to the packaging unit with a linear speed calculated in such a way that the glue remains on the packaging material, before applying pressure to said at least one joint, for a length of time less than an open time of the glue. 
     
     
         10 . The method according to  claim 1 , wherein the objects have been purchased through the Internet and are packaged in the packaging unit before being dispatched to the people who ordered them. 
     
     
         11 . The method according to  claim 1 , wherein the packaging material is paper. 
     
     
         12 . An apparatus comprising:
 an infeed conveyor for receiving a plurality of objects, having different dimensions to each other;   an intermediate conveyor, located downstream of the infeed conveyor for receiving a flow of objects from the infeed conveyor in an advancement direction;   a packaging unit located downstream of the intermediate conveyor for producing a plurality of packages starting from a web of packaging material, each package containing one object;   
       wherein along the intermediate conveyor at least one sensor is arranged for controlling whether, in the flow of objects advancing along the intermediate conveyor, there are empty positions in which an object is missing and in that the intermediate conveyor comprises a plurality of conveyor belts arranged in sequence along the advancement direction so that, if an empty position is detected, the objects which follow the empty position are accelerated to fill the empty position, the production speed of the packaging unit being adjustable in such a way as to keep in the intermediate conveyor a predetermined average filling level. 
     
     
         13 . The apparatus according to  claim 12 , and further comprising an object rejecting device interposed between the infeed conveyor and the intermediate conveyor, the object rejecting device comprising a tiltable conveyor which can be positioned in a first configuration, in which the tiltable conveyor is arranged horizontally for conveying the objects from the infeed conveyor to the intermediate conveyor, the tiltable conveyor being further positionable in a second configuration in which the tiltable conveyor is tilted downwards to divert the objects on a removal conveyor. 
     
     
         14 . The apparatus according to  claim 12 , wherein the packaging unit comprises an applying device for applying glue on the web of packaging material, a plurality of deflector elements for folding the web of packaging material and forming a tubular enclosure around the objects, at least one presser for applying pressure to overlying portions of the web of packaging material on which the glue is present, a cutting blade for separating successive packages from the web of packaging material.