Patent Publication Number: US-2021179310-A1

Title: Machine and method for labeling containers

Description:
The present invention relates to a machine and a method for labeling containers. 
     Labeling machines are known which make it possible to automatically carry out the application of printed labels on containers, in general, and bottles, in particular. 
     Typically, the labeling machines are provided with a transfer drum that makes it possible to apply, on each bottle that is progressively presented before the transfer drum, a label which is obtained by cutting a continuous ribbon of labels which is unwound from a reel. 
     Before being applied on the corresponding bottle, each label receives, along its leading, or front, edge and along its trailing, or rear, edge with respect to its advancement direction, a quantity of glue from a gluing assembly, which can be constituted by a gluing roller or by a spraying assembly. 
     Generally, in this type of labeling machine, the bottles are conveyed by a rotating carousel which is provided with a plurality of supports for the individual bottles, which are adapted to rotate the bottles about their own axis, and is provided with an unwinding roller which makes it possible to take the ribbon of labels from the reel and feed it to a cutting drum, on which, by way of cutting means, the ribbon is cut between one label and the next. 
     Subsequently, the individual labels, once separated after cutting, are transferred from the cutting drum to the transfer drum. In particular, the labels are arranged so that they adhere to the transfer drum at respective sectors of the outer lateral surface of the transfer drum. Such sectors are angularly mutually spaced apart about the axis of the transfer drum and are separated from each other by a separation segment. 
     Typically the gluing assembly is arranged so as to face the transfer drum and apply the glue at the leading and trailing edges of the individual labels placed in the sectors of the outer lateral surface of the transfer drum, before the labels are brought by that transfer drum to adhere to the corresponding bottles carried by the rotating carousel. 
     In particular, if the gluing assembly is constituted by a gluing roller, then at opposite ends of the various sectors of the transfer drum are two adhesive bonding regions, which are in relief with respect to the main lateral surface of the transfer drum and which are defined by respective blocks called runners, on which the leading and trailing edges of the labels come to rest, so that when the labels pass in front of the gluing drum, the latter applies only two strips of glue to those labels. 
     In order to prevent the labels from remaining attached to the gluing roller, they are kept adhered to the lateral surface of the transfer drum by way of holes, provided on the lateral surface of the transfer drum, which are connected to air suction means. 
     During the operation of the labeling machine, since individual separated labels adhere to the transfer drum, it often happens that the transfer drum can be smeared with glue, which results in the machine having to be shut down in order to carry out the necessary cleaning thereof. 
     If on the other hand the gluing assembly is constituted by a spraying assembly, then the latter, in order to enable the application of the glue on the labels at the high speeds with which the labels move on the transfer drum, is usually made up of a battery of several spray guns which are arranged laterally to the transfer drum. 
     In particular, each one of such spray guns is provided with a plurality of glue dispenser nozzles which are directed toward the outer lateral surface of the transfer drum and which, at each activation of the corresponding spray gun, are each capable of emitting a given quantity of glue which is sprayed on the labels being conveyed by the transfer drum. 
     In particular, the dispenser nozzles of each spray gun are arranged mutually side-by-side along a row that extends parallel to the direction of transverse extension of the labels, i.e. substantially parallel to the axis of the transfer drum, and are mutually spaced apart, along the row, by a distance that is dictated by technical requirements aimed at ensuring a valid and regular operation of the spray gun at high speeds. 
     In this manner, the dispenser nozzles of each spray gun apply a corresponding plurality of droplets of glue on the labels, called glue spots, which are arranged along a row that is parallel to the direction of transverse extension of the labels and which are spaced apart, from each other, by a distance that is practically equal to the distance between the dispenser nozzles. 
     In order to be capable of applying a row of droplets of glue on the labels with a distance between two consecutive droplets along the row that is smaller than the distance between the dispenser nozzles of the spray guns, the spray guns are arranged side by side, one after the other, along a direction parallel to the advancement direction of the labels and are arranged differently beside each other along a direction parallel to the axis of the transfer drum, so that the dispenser nozzles of each spray gun are arranged offset with respect to those of the other spray guns. 
     The spray guns, thus arranged, are activated sequentially one after the other so that the droplets of glue applied by the spray guns after the first spray gun encountered by the label come to be positioned in an interleaved position between the droplets applied by each preceding spray gun. 
     In order to enable the spray guns to dispense the glue one after the other very quickly, given the high speed of the labels conveyed by the transfer drum, they must work at relatively high levels of pressure of the glue, with consequent considerable production of glue vapors and risk of unwanted smearing of the components of the machine. 
     The aim of the present invention is to provide a machine for labeling containers which is capable of improving the known art in one or more of the above mentioned aspects. 
     Within this aim, an object of the present invention is to provide a machine for labeling containers that makes it possible to prevent unwanted smearing of the transfer drum or other components of the machine with glue. 
     Another object of the present invention is to provide a machine for labeling containers that constitutes a considerable simplification in terms of construction and operation compared to traditional machines of this type which are fitted with a glue spraying assembly. 
     Another object of the present invention is to provide a machine for labeling containers that can operate positively using only one spray gun. 
     Another object of the present invention is to provide a machine for labeling containers that is capable of offering the widest guarantees of reliability and safety in its operation. 
     Another object of the present invention is to provide a method for labeling containers that makes it possible to execute an optimal application of glue on the labels. 
     Another object of the present invention is to provide a machine for labeling containers that is of low cost, so as to be competitive from a purely economic viewpoint as well. 
     This aim and these and other objects which will become better apparent hereinafter are achieved by a machine for labeling containers, according to the invention, as defined in claim  1 . 
    
    
     
       Further characteristics and advantages of the present invention will become better apparent from the description of a preferred, but not exclusive, embodiment of the machine according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings wherein: 
         FIG. 1  is a schematic plan view from above the machine according to the invention; 
         FIG. 2  is a front elevation view of a spray gun of the machine according to the invention; 
         FIG. 3  is a front elevation view of a labeling ribbon highlighting the glue spots, at the leading end and at the trailing end of the various labels, that can be applied by the spray gun of the machine according to the invention; 
         FIG. 4  is a side view of a label with glue spots that can be applied by the spray gun of the machine according to the invention and a corresponding container, to highlight the correspondence between the position of glue spots placed proximate to the leading edge of the label with raised portions that are present on the container; 
         FIGS. 5 to 10  are schematic plan views from above of a sequence of steps of operation of the machine according to the invention; 
         FIG. 11  is a schematic plan view from above of the machine according to the invention with a possible variation of embodiment of the cutting means. 
     
    
    
     With reference to the figures, the machine for labeling containers, according to the invention, generally designated with the reference numeral  1 , comprises conveyor means  2  that make it possible to move one or more labels  3  to be applied on the containers  4  to be labeled according to a advancement direction  100 . 
     Such conveyor means  2  comprise a transfer drum  5  which is actuated in rotation about its own axis  5   a  and which makes it possible to bring the individual labels  3  into contact with corresponding containers  4 , which are supported by a conveyor  6  which moves the containers  4  in an advancement direction along a trajectory  6   a,  for example substantially shaped like a circular arc, and which is, preferably, constituted, as is normal, by a rotating carousel which is provided with a plurality of supports which are designed to receive a respective container  4  resting thereon and to rotate it about its own axis. 
     A spraying assembly  7  faces the transfer drum  5  and is intended to apply glue on the labels  3 , in order to allow the subsequent adhesion of the latter to the corresponding containers  4 . 
     According to the invention, the spraying assembly  7  comprises at least one spray gun  8  which has a plate-like glue dispensing body  9  which faces the lateral surface of the transfer drum  5  and is passed through by a plurality of dispensing ports  10 , which are adapted to connect the inside of the spray gun  8  with the outside. 
     The dispensing ports  10  are, in particular, arranged mutually spaced apart along at least one row which extends substantially parallel to the axis  5   a  of the transfer drum  5 , in order to enable the application on the labels  3  of at least one line of glue spots  11  which extends transversely to the advancement direction of the labels  3 . 
     Control means  12  are further provided, which conveniently comprise an electronic controller and are functionally connected to the conveyor means  2  and to the spray gun  8  and the function of which is to actuate a slowing of the advancement speed of the labels  3 , with respect to the spray gun  8 , before actuating the activation of the spray gun  8  for executing the application of the glue on the labels  3 . 
     It should be noted that, according to a preferred embodiment, the spraying assembly  7  can be provided with only a single spray gun  8 . 
     With reference to the embodiment shown in  FIG. 1 , the conveyor means  2  comprise, upstream of the transfer drum  5 , an unwinding assembly  13  that feeds the transfer drum  5  with a labeling ribbon  14  on which a plurality of labels  3  are printed continuously along its extension, by making it advance along the advancement direction  100 . 
     Conveniently, the unwinding assembly  13  comprises two feeding rollers  13   a  and  13   b,  which engage the labeling ribbon  13  on mutually opposite sides and are rotated in mutually opposite directions in order to entrain the labeling ribbon  14  in the direction of the transfer drum  5 . 
     Advantageously, in order to allow to the transfer drum  5  to receive the labeling ribbon  13  by making it adhere to its lateral surface, the transfer drum  5  is provided, on its lateral surface, with a plurality of suction holes, which are connected to air suction means. 
     In particular, the transfer drum  5  is further rotationally actuated at a constant speed, which is synchronized with the speed of the conveyor  6 , so as to be in phase with it and be able therefore to deliver a label to a corresponding container  4  arriving on the conveyor  6 . 
     Conveniently, the transfer drum  5  is provided with means for cutting the labeling ribbon  13 , which are arranged on its lateral surface and can be activated on command by activation means, in order to carry out the cutting of the labeling ribbon  13  at the connecting region  15  between two consecutive labels  3  that are present along the labeling ribbon  14 . 
     In particular, the control means  12  activate the spray gun  8  so as to apply the glue on at least one of the labels  3  that are present along the labeling ribbon  14 , before the cutting means are activated by the corresponding activation means, for the purpose of carrying out the separation of the label or labels  3 , on which the spray gun  8  has applied the glue, from the labeling ribbon  14 . 
     Preferably, the means for cutting the labeling ribbon  13  are constituted by a plurality of cutting devices  16 , which are mutually angularly spaced apart about the axis  5   a  of the transfer drum  5  and can be activated on command, independently, in order to carry out the cutting of the labeling ribbon  14 , so as to separate a label  3  from it in each instance. 
     For example, the cutting devices  16  can each be provided by a respective cutting knife  16   a,  which is supported by the transfer drum  5  and can be actuated to move, in order to carry out the cutting of the labeling ribbon  14 , by a respective working cylinder  16   b,  which is also fitted on the transfer drum  5  and, advantageously, is functionally connected to the control means  12 . 
     According to a possible alternative embodiment, shown in  FIG. 11 , each cutting device  16  is provided with a respective blade  16   c,  which is integral with the transfer drum  5  and accommodated in a respective chamber  16   d,  which is defined in the transfer drum  5  and open at the lateral surface thereof. The chamber  16   d  of each cutting device  16  is connected to air extraction means, which, once activated and connected to the chamber  16   d , make it possible to attract, inward into the chamber  16   d,  the segment of the portion of the labeling ribbon  14  resting on the lateral surface of the transfer drum  5  which is in front of the chamber  16   d,  so as to bring such segment into contact with the blade  16   c  and as a consequence cut it. 
     With reference to  FIG. 2 , in an embodiment, in the plate-like dispensing body  9  of the spray gun  8  there are, conveniently, at least two rows  16   a  and  16   b  of glue dispensing ports  10  and, more specifically, at least one first row  16   a  and at least one second row  16   b,  which are mutually parallel and are spaced apart, from each other, along a direction that is substantially parallel to the advancement direction  100  of the labels  3 . 
     In practice, the first row  16   a  of dispensing ports  10  is arranged downstream of the second row  16   b  according to the advancement direction  100  of the labeling ribbon  14  on the transfer drum  5 . 
     In particular, the two rows  16   a  and  16   b  of dispensing ports  10  are intended to apply respective lines  17   a  and  17   b  of glue spots  11  on the labels  3 . 
     Advantageously, the control means  12  are adapted to actuate the activation of the spray gun  8  in order to enable the application of such lines  17   a  and  17   b  of glue spots  11  by the rows  16   a  and  16   b  of dispensing ports  10  on two consecutive labels  3  which are present along the labeling ribbon  13 , before these two consecutive labels  3  are separated from the labeling ribbon  14  by way of cutting it. 
     In detail, the lines  17   a  and  17   b  of glue spots  11  are, conveniently, applied, respectively, proximate to the trailing edge  3   a  of one of the two consecutive labels  3 , in particular the one that is in front of the other with respect to the advancement direction  100  of the labeling ribbon  14 , and proximate to the leading edge  3   b  of the other of the two consecutive labels  3 . 
     More precisely, the line  17   a  of glue spots  11  is applied by the first row  16   a  of dispensing ports  10  proximate to the trailing edge  3   a  of the label  3  that, of the two consecutive labels  3 , is in front of the other, with respect to the advancement direction  100  of the labeling ribbon  14 , while the line  17   b  of glue spots  11  is applied by the second row  16   b  of dispensing ports  10  proximate to the leading edge  3   b  of the other of the two consecutive labels  3  i.e. the one behind. 
     Conveniently, the control means  12  are adapted to drive the unwinding assembly  13  in order to vary the speed with which the labeling ribbon  14  is fed to the transfer drum  5  by the unwinding assembly  13 , during the rotation of the transfer drum. 
     In particular, the control means  12  are capable of controlling the unwinding assembly  13  so as to be able to vary the speed of feeding the labeling ribbon  14  to the transfer drum  5  between at least two speeds, respectively a first speed, which is synchronized with respect to the speed of the transfer drum  5 , so that the labeling ribbon  14  is entrained by the transfer drum  5  without sliding, and at least one second speed, which is lower than the first speed and, preferably, nil i.e. equal to zero. 
     More specifically, the control means  12  actuate a slowing of the speed of feeding the labeling ribbon  14  to the transfer drum  5 , in order to take it from the first speed to the second speed, at least at the arrival, at the spray gun  8 , of the trailing edge  3   a  and of the leading edge  3   b  of two consecutive labels  3 . 
     Once such slowing of the speed of feeding the labeling ribbon  14  has been actuated, the control means  12  actuate the activation of the spray gun  8 , in order to apply, proximate to the trailing edge  3   a  and proximate to the leading edge  3   b  of the two consecutive labels  3  which have arrived at said spray gun  8 , respective lines  17   a  and  17   b  of glue spots  11  and, subsequently, they actuate the increase of the speed of feeding of the labeling ribbon  14 , in order to return it to the value preceding the slowing, i.e. to the first speed. 
     Conveniently, such increase of the speed of feeding the labeling ribbon is actuated by the control means  12  after they actuated the activation of the cutting means in order to carry out the cutting of the labeling ribbon  14  at the connecting region  15  between the two consecutive labels  3  on which the spray gun  8  has applied the glue. 
     More preferably, upon arrival, at the spray gun  8 , of the trailing edge  3   b  and of the leading edge  3   a  of two consecutive labels  3  that are present on the labeling ribbon  14 , the control means  12  actuate the stop of the unwinding assembly  13  with consequent stop also of the advancement of the labeling ribbon  14  with respect to the spray gun  8 , which can thus apply the lines  17   a,    17   b  of glue spots  11  on the two consecutive labels  3  with the labeling ribbon  14  stationary. 
     During the stop or, in any case, the slowing of the advancement of the labeling ribbon  14 , the transfer drum  5 , continuing to rotate about its own axis  5   a  at the same speed, swipes on the labeling ribbon  14 , thus enabling one of the cutting devices  16  to be brought to the connecting region  15  between the two consecutive labels  3  on which the spray gun  8  has applied the lines  17   a  and  17   b  of glue spots  11 . Once one of the cutting devices  16  reaches the connecting region  15  between the two consecutive labels  3  on which the spray gun  8  has applied glue, or before this point, the control means  12  will actuate the increase of the speed of feeding the labeling ribbon  14  to the transfer drum  5  by the unwinding assembly  13 , so that the labeling ribbon  14  can restore its advancement to the first speed in the advancement direction  100 , and they will then actuate the cutting device  16  which in the meantime will have reached the connection region  15  between the two consecutive labels  3 , so that such cutting device  16  cuts the labeling ribbon  14  between the two consecutive labels  3 , separating them from each other. 
     As a consequence, the label  3  that, of the two consecutive labels  3 , is in front of the other, with respect to the advancement direction  100 , no longer being connected to the labeling ribbon  14 , can be entrained by the transfer drum  5  toward the corresponding container  4 . 
     Delving deeper into the details of the spray gun  8 , the dispensing ports  10  each comprise a respective spray nozzle that makes it possible to create a glue spot  11  of uniform dimensions on the labels  3 . 
     Conveniently, the spray gun  8  is provided by a main body  8   a  which defines at least one glue accumulation chamber  8   b,  which is supplied with glue at low pressure and is closed on the side that is directed toward the transfer drum  5  by the plate-like body  9 . 
     It should be noted that the dispensing ports  10  can optionally be arranged along the respective row  16   a  or  16   b  at mutually irregular distances. 
     In particular, conveniently, the distance between at least two dispensing ports  10  of one row  16   a,    16   b  can be different from the distance between other dispensing ports  10  of the same row  16   a,    16   b.    
     It is also possible for the dispensing ports  10  of one row  16   a,    16   b  to be distributed along the corresponding row  16   a,    16   b  differently from the dispensing ports  10  of the other row  16   a,    16   b.    
     More specifically, for example, the distance between the dispensing ports  10  of one row  16   a,    16   b  can be different from the distance between the dispensing ports of the other row  16   a,    16   b.    
     It should be noted that, according to a possible embodiment, the dispensing ports  10  at least of the second row  16 , i.e. of the row intended to apply the line  17   b  of glue spots  11  proximate to the leading edge  3   b  of the labels  3 , can, for example, be arranged so that the corresponding glue spots  11  are located at corresponding raised portions  4   a  which are present on the lateral surface of the containers  4 , as shown schematically in  FIG. 4 . This offers the possibility of ensuring a perfect adhesion of the labels  3  even on containers  4  that have a variously contoured lateral surface. 
     Operation of the machine according to the invention is the following. 
     In a first step of operation, the unwinding assembly  3  feeds the labeling ribbon  14  to the transfer drum  5  at a first speed which substantially corresponds to the peripheral speed of the transfer drum  5 , so that the labeling ribbon  14  and the transfer drum  5  are synchronized with each other. 
     With reference to  FIG. 5 , when the trailing edge  3   a  and the leading edge  3   b  of two consecutive labels  3  approach or in any case are positioned at the spray gun  8 , the control means  12  actuate the unwinding assembly  13  to slow the advancement speed of the labeling ribbon  14  down to a second speed, lower than the first speed, and more preferably until it stops. It should be noted that, in this situation, the transfer drum  5 , which continues rotating at the same speed, will begin to swipe on the labeling ribbon  14 . 
     At this point, as shown in  FIG. 6 , the control means  12  activate the spray gun  8 , so that the first row  16   a  of dispensing ports  10  applies a line  17   a  of glue spots  11  proximate to the trailing edge  3   a  of the label  3  that is in front, with respect to the advancement direction  100  of the labeling ribbon  14 , and the second row  16   b  of dispensing ports  10  applies a line  17   b  of glue spots  11  proximate to the leading edge  3   b  of the following label  3 . 
     In the meantime, the swiping of the transfer drum  5  on the labeling ribbon  14  which occurs as a result of reducing the advancement speed of the labeling ribbon  14  enables one of the cutting devices  16  on the transfer drum  5  to be brought toward the connecting region  15  between the two consecutive labels  3  which have received, respectively, the lines  17   a  and  17   b  of glue spots  11 . 
     At this point, the control means  12  actuate the unwinding assembly  13  in order to obtain the increase of the speed of the labeling ribbon  14 , so that it can be progressively brought from the second speed up to the first speed. The increase in the speed of the labeling ribbon  14  by the unwinding assembly  13  occurs in such a way that, while the labeling ribbon  14  moves at a speed comprised between the second speed and the first speed, one of the cutting devices  14  will continue to progressively approach the connecting region  15  of the two consecutive labels  3  that have received the glue, as shown in  FIG. 7 , and, once said cutting device  14  has reached the connecting region  15  of the two consecutive labels  3  that have received the glue, the labeling ribbon  14  will in turn have again reached the first speed so as to move synchronously with the transfer drum  5  and, therefore, also with the cutting device  14  that has reached the connecting region  15  of the two consecutive labels  3  that have received the glue, as shown in  FIG. 8 . 
     Subsequently, as shown in  FIG. 9 , the cutting device  16  that has reached the connecting region  15  between the two consecutive labels  3  that have received the glue is activated, so as to carry out the separation from the labeling ribbon  14  of the front label  3 , which, since it is no longer attached to the labeling ribbon  14 , is entrained by the transfer drum  5 , which, continuing its rotation, will bring the cut label  3  to the region of tangency between the transfer drum  5  and the conveyor  6 , where the adhesion of the cut label  3  to the corresponding container  4  takes place, as shown in  FIG. 10 . 
     At this point, operation resumes as described above. 
     From the foregoing it can be seen that the invention is capable of fully achieving the set aim and objects. 
     All the characteristics of the invention, indicated above as advantageous, convenient or similar, may also be missing or be substituted by equivalent characteristics. 
     The individual characteristics set out in reference to general teachings or to specific embodiments may all be present in other embodiments or may substitute characteristics in such embodiments. 
     The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. 
     In practice the materials employed, provided they are compatible with the specific use, and the dimensions and shapes, may be any according to requirements. 
     Moreover, all the details may be substituted by other, technically equivalent elements. 
     The disclosures in Italian Patent Application No. 102018000006434 from which this application claims priority are incorporated herein by reference. 
     Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.