Abstract:
Dosage system applied to automatic packaging machinery, capable of measuring the mass of solid products in bulk and adjusting the final mass of the package to be baled, so that the average masses of each package result in a value pre-established, as well as the standard deviation of the masses average result in a value within a tolerance range previously defined.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention, which belongs to the field of engineering of mechanical devices of industrial use, covers a solid product provision system applied to automatic packaging machinery, using the final mass control of the batch composed by packages whose average weight is the target of the dosage system. 
       BACKGROUND OF THE INVENTION 
       [0002]    The automatic packing machines have historically aimed at making the composition of the packages filling the container with the product to be packed, forming what is called the primary packaging. Its final weight or volume must be consistent with the values previously established and/or programmed and are controlled at the time of filling the package with the product. 
         [0003]    Thus, devices for measuring mass and volume may be associated to the packaging machinery, in order to enable the filling of the package while maintaining the weight or volume of the package within the desired specifications, with the least possible deviation. 
         [0004]    When it comes to fluid products such as liquids or pastes, the control is easier, since you can adjust the amount of the product to be packed more precisely, halting the package supply at the exact point where the volume or mass reach the desired value. 
         [0005]    In the case of solid products, however, this task presents an additional difficulty related to the indivisible mass of the unit element of the solid product. For example, beans and bullets, which individually have a minimum mass that can not be divided. That is, when forming a package of a solid product, the mass of the particle can have a value greater than the one desired to form the final mass of the package. For instance, a bullet of about 7 g can contribute with a significant additional mass in a package of gum that requires 3 g to compound its standard mass. Thus there will be a quantity that exceeds the standard weight of the package in question and it may be considered in the accountability of the average weight of the packages of a certain batch or a certain bale. 
         [0006]    Therefore, it is necessary that the mass control system, combined with measurement devices, may account for these amounts of particulate products, surplus or missing, to compensate through the process of packaging the batch of product, ensuring that the mass of each package should be as close as possible to the limit, and the average package of the lot to be formed, meaning that the standard deviation is minimized. 
         [0007]    Additionally, the difficulty of reusing the material eventually disposed when the adjustment of weighing can become a source of significant waste in the packaging process, incurring a higher cost of production in order to overcome these wastes. For example, during the adjustment process in order to reach the ideal value of mass for each package, it is inevitable, in the current model, the disposal of some packages, whose masses are far from the value previously assigned. Thus, some packages formed in the process are disposed, incurring not only in the eventual disposal of products, but also in rejecting the packages used. 
       ANALYSIS OF STATE OF THE ART 
       [0008]    Document MU8601890-6 advances a volumetric feeder for applicators and bagging equipments of granular products or powders with controlled volume for solid products and can be applied to bag several solid products, with a predetermined dosage. 
         [0009]    Patent PI0402405-2 exposes a volumetric feeder to dose precisely and transporting microgranulate material and microspheres, with the adjustment of the screw in relation to the appropriate feeding tube to maintain its speed ratio. 
         [0010]    Document PI8405869-2 reveals the process and control and command device of filling containers, comprising a scale and a volumetric feeder of cylindrical glassware. The piston rod of the cylinder is actuated by a cam possibly comprising an adjustable portion, with the interposition of elastic means in the path of a container to a filling station. The following operations take place: adjustment of the empty container while filling the volumetric feeder with a volume of product higher than a password value; transfer of the product contained in the volumetric feeder of the feeder to the recipient and continuous weighing until the product weight inside the container has reached the password value, the blocking of the piston rod, consecutively to the termination of the dispensing orifice of the volumetric feeder is modified so that the breakpoint of the filling occurs between two specified points of the cam. 
         [0011]    Document EP 0147263 (A1) anticipates a method and apparatus to check and control the filling of containers for a given mass of product, the apparatus being provided with a carousel filled with various filling points, each with a volumetric feeder with a timer or a feeder, wherein some of the items include a balance, wherein the steps include: (i) weighing the empty container, simultaneously filling the volumetric feeder, (ii) transfer of the volume contained the volumetric feeder, (iii) weighing the container filled and (iv) comparison after the container tare. 
         [0012]    The document EP 0120778 (A1) discloses a process and device for filling a recipient, with a step of volumetric dosage associated to a stage of weighing. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0013]    This invention describes a dosing system applied to an automatic packaging machinery, capable of measuring the mass of solids in bulk and adjust the final mass of the package to be baled so that the average masses of each package result in a pre-set value, as well as the standard deviation of the masses average results in a value within a tolerance range determined in advance. 
         [0014]    It also describes a control system of supply of particular products, associated with the device for measuring weight applied to an automatic packaging machinery, which monitors the mass allocated in each packet to check any shortage or excess weight in the package being formed, allowing the compensation of this difference throughout the packaged batch or the bale to be formed, while keeping the average masses of the batch packages within the values, indicators and technical criteria established in advance, through the handling of the individual element of the particulate material being packaged. 
         [0015]    Moreover, it outlines a control system for the mass of particulate solids articles to be packaged in automatic packaging machinery, which provides conditions for monitoring the mass that composes each package in order to control the average package of the batch to be packed or the bale to be formed. 
         [0016]    This system performs the monitoring of the mass inserted in each formed package, associated with the device that measures the primary volume of the material to be packed, making it possible to identify the difference in the amount previously determined to be packaged so that it can perform the adjustment of the primary volume to the next measurement, approximating the amount desired, and thus minimizing the difference between the measured and desired value. 
         [0017]    If compared with those comprised in the state of the art, this innovation greatly improves a number of problems, especially with regard to measurement effectiveness of packaging machines since the system for mass control, combined with measurement devices, account for effectively quantities of particulate products, surplus or missing, compensating throughout the packaging process of the product batch and ensuring that the mass of each package should be as close as possible to the limit, minimizing the common standard deviation for such equipment. 
         [0018]    These meters enable the continuous adjustment of the mass of the packages that are being sequentially formed by a packaging machinery, so as to maintain the standard deviation of the mass of the packets formed within a range previously established and with a high degree of accuracy. 
     
    
     
       DESCRIPTION OF FIGURES 
         [0019]      FIG. 1  shows a perspective frontal view of the packaging machinery mechanism, wherein the volumetric feeder ( 1 ), primary mass meters ( 2 ), secondary mass meters ( 3 ), particle selectors ( 4 ) and packaging funnel ( 5 ) are noticed. 
           [0020]      FIG. 2  shows a perspective rear view of the packaging machinery mechanism, wherein the volumetric feeder ( 1 ), primary mass meters ( 2 ), secondary mass meters ( 3 ), particle selectors ( 4 ) and packaging funnel ( 5 ) are noticed. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    This invention outlines a control system for the mass of the particle-solid articles to be packaged in packaging machinery automatically, which provides conditions for monitoring the mass that compound each package in order to control the average package of the batch to be wrapped or bale to be formed. 
         [0022]    This system performs the monitoring of the mass inserted in each package formed, associated to the device that measures the primary volume of the material to be packaged, making it possible to identify the difference in the amount previously determined to be packaged so that it can perform the adjustment of the primary volume to the next measurement, approximating the amount desired, and thus minimizing the difference between the measured and desired value. 
         [0023]    Therefore, the system has a volumetric feeder ( 1 ) that performs a first input of product to be packaged to the primary meter ( 2 ), which perceives the mass of the volume contributed and fixes, if necessary, the adjustment of the volumetric feeder ( 1 ), effecting the correction according to the measured mass. That is, in case of excess weight in relation to the predetermined value, the primary mass meter ( 2 ) controls the proportional reduction of the volume to be accommodated by the volumetric feeder ( 1 ), and, if the measured mass is below the value previously determined, the primary mass meter ( 2 ) controls the proportional increase in the volume to be accommodated by the volumetric feeder ( 1 ). Thus, the subsequent volume to be accommodated by the volumetric feeder ( 1 ) is already set in relation to the mass desired, reducing the need for correction to be performed by the primary mass meter ( 2 ). 
         [0024]    In order to adjust the weight to be packaged, approximating it to the value previously set, a second device for measuring mass ( 3 ) is associated with the control system, making the final correction of the mass of the package to be formed in association with a particle device selector ( 4 ), capable of provisioning each individual particle of the solid material to be packed. Thus, the particles are added to the mass contained in the secondary mass meter ( 3 ), performing a fine tuning of the package mass formed until forming the desired mass. 
         [0025]    Eventually, the mass to be added, i.e. the mass of each particle is greater than the difference between the value of the mass of the package and the desired amount to complete the package mass. In this case, the system automatically chooses between adding the particle mass to the package, even if the value is exceeded, and not adding the particle, leaving the package with a mass slightly smaller than the said stipulated amount. In both cases, the system stores information about the differences of mass accumulated in order to compensate the difference over the batch to be formed by packages. 
         [0026]    The compensation of the mass difference of packages, along the batch to be formed, is made possible by the combination of the particle mass measurement value, the mass value of the package under formation and the value of the difference of accumulated mass when forming the package. The dosage system has the ability to perceive the need to add the particle in each package, compensating the difference of accumulated mass so that its value is maintained low, tending to zero. 
         [0027]    For example, when adding the particle result in exceeding the default value of the mass of the package, there is a decision to be made, which depend on the value package mass at that time. If the mass of the package is below the limit of standard deviation established, the device ( 4 ) promotes the aggregation of the particle to the package, slightly surpassing the value of the standard mass of the package. However, if the mass of the package is within an acceptable level, the device ( 4 ) can avoid sending such particle to the package, which would be with a lower value than the default, but within an acceptable margin. In both cases, information about the difference of the mass of the package against the default value would be stored for consideration of the composition of the next packet, so that the average mass of the formed packages are better controlled throughout the batch packaging or the bale under formation. 
         [0028]    Another significant aspect of this invention relates to the possibility of reducing operating costs, since the dosage system of the present invention allows the formation of packets to take place only after the proper weighing of the contents to be packed, focusing on the net weight, unlike the existing models, which consider the gross weight. 
         [0029]    Further, the proposed system allows the material eventually disposed when the mass of the packages is corrected can be reused directly in the packaging process, since it allows for the disposal of the material before the formation of the package. 
         [0030]    This invention is not limited to the representations mentioned or illustrated herein, and it has to be comprehended in its wide scope. Many changes and other representations of the invention will come in mind of those skilled in the technique to which this invention belongs, having the learning benefit presented in previous descriptions and attached drawings. Further, it is to be understood that the invention is not limited to the disclosed specific shape and that changes and other shapes are understood as enclosed within the scope of the attached claims. Although specific terms are nominated herein, they are only used in a generic and descriptive form and not for a limiting purpose.