Abstract:
A labeling machine for labels printed on continuous film, comprising, in an intermediate position between a motorized reel and a feed roller, a tunnel provided with suction elements adapted to determine on the film in transit inside it an attraction that gives it a bent configuration, elements being provided which are adapted to control the depth of the bend, the tunnel being provided with a bottom and a lid that are adapted to align the film at a constant height.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a labeling machine for labels printed on continuous film. 
       BACKGROUND ART 
       [0002]    It is known that there are labeling machines designed to process labels printed on a continuous film that is unwound from a motorized reel, and that said film can be pre-pasted, i.e., provided with paste, at one face, or not, and in this case suitable pasting means are provided within the machine. 
         [0003]    Such labeling machines comprise a drum that accompanies the film, retaining it so that it adheres to the surface by way of suction generated at the surface, cutting the individual labels up to being applied to corresponding containers conveyed by conveyance means, which are commonly constituted by a rotating carousel. 
         [0004]    The film of the labels is fed to the drum by means of a feed roller, which, in order to be able to work correctly at the high speeds currently required, needs to receive the film unwound from the reel in extremely low and constant tension conditions, the film being further aligned at a constant height. 
         [0005]    For this purpose, the background art provides for the presence of tensioning devices combined with alignment devices, which however are not entirely satisfactory. 
       DISCLOSURE OF THE INVENTION 
       [0006]    Therefore the aim of the present invention is to provide a labeling machine in which the arrival of the film of the labels to the feed roller is ensured in such conditions as to ensure optimal operation of the roller. 
         [0007]    The above aim and other objects which will become better apparent hereinafter are achieved by a labeling machine for labels printed on continuous film, according to the invention, comprising a feed roller that conveys the film of the labels from a motorized reel to a drum that accompanies the film, cutting the individual labels, up to being brought to application on corresponding containers supported by conveyance means, characterized by the presence, in a position comprised between said motorized reel and said feed roller, of a tunnel provided with suction means adapted to determine on the film in transit inside it an attraction that gives it a bent configuration, means being provided which are adapted to control the depth of said bend, and said tunnel being provided with a bottom and a lid that are adapted to align the film at a constant height. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Further characteristics and advantages of the present invention will become better apparent from the description of two preferred but not exclusive embodiments thereof, illustrated by way of non-limiting example in the accompanying drawings, wherein: 
           [0009]      FIG. 1  is a schematic plan view of the labeling machine according to the invention; 
           [0010]      FIG. 2  is a view of the detail of the tunnel; 
           [0011]      FIG. 3  is a schematic plan view according to another embodiment of the labeling machine according to the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0012]    It should be specified that the embodiment shown in  FIG. 1  is designed to process a film of labels that is not pre-pasted, while the embodiment of  FIG. 3  is designed to process a pre-pasted film, and that both comprise a feed roller  1  that conveys from a motorized reel  2  the film of the labels  3  to a drum  4  that accompanies the film, cutting the individual labels up to being applied to individual containers  5  conveyed by a rotating carousel  6 . 
         [0013]    In the case of the machine of  FIG. 1 , which processes a film of labels that is not pre-pasted, means  7  for pasting the film  3  are provided, which obviously are absent in the case of the machine of  FIG. 3 , which processes pre-pasted films. 
         [0014]    In both embodiments of  FIGS. 1 and 3 , in a position that directly precedes the feed roller  1 , there is a tunnel, generally designated by the reference numeral  8 , that is described in detail with particular reference to  FIG. 2 . 
         [0015]    Tunnel  8  is provided with suction means, which comprise a fan  9  and are adapted to provide on the film of labels in transit within it, between the input roller  8   a  and the output roller  8   b,  an attraction that is such as to induce it to arrange itself along a bend  3   a,  whose depth is controlled by way of appropriate means that are adapted to send signals to the control electronics of the machine. 
         [0016]    Such means comprise, in the embodiment of  FIG. 1 , two photocells  10   a,    10   b,  which are conveniently spaced in the direction of the axis of symmetry of the loop, and instead comprise, in the embodiment of  FIG. 3 , only a photocell  11  located at the plane of symmetry of the loop; of course, the described means are interchangeable between the two embodiments. 
         [0017]    The presence of the tunnel  8  according to the invention ensures occurrence of the condition in which the film of labels  3  reaches the feed roller  1  in the conditions of extremely low and constant tension that are required for optimum operation; moreover, the tunnel provides, by means of its bottom  8   c  and its lid  8   d,  a guide at the respectively lower and upper edges of the film  3  that ensures perfect alignment at a constant height. 
         [0018]    In order to obtain such a flexibility of operation of the tunnel as to allow to change the format of the labels being processed, the lid  8   d  is provided with means that are adapted to determine the arrangement thereof at a variable height from the bottom  8   c,  without altering the fact that if the format change is not intended, the lid is at a fixed height. 
         [0019]    Such means thus comprise four columns  12 ,  13 ,  14 ,  15 , which are jointly connected to the lid  8   d  and are provided with identical equipment, and therefore only the column  15  will be described in detail. 
         [0020]    The column  15  is provided with three rods  16 ,  17 ,  18  of different lengths, which are applied in an adjustable manner to a rotatable support  19 , such rods being adapted to rest selectively at the end, as a consequence of the rotation of the support  19 , on a fixed frame  8   e  of the lid  8   d.    
         [0021]    In the situation of  FIG. 2 , the longer rods  17 , of the four columns rest on the frame  8   e,  and accordingly the lid  8   d  is at the highest level; to lower it for example by a first extent, it is sufficient to rotate the supports  19  and bring the intermediate-length rods  16  of the four columns to rest with the edge  8   e,  and a further lowering can be obtained by making the shorter rods  18  rest on such edge. 
         [0022]    Whereas in the case of the machine of  FIG. 1 , designed to process a film that is not pre-pasted, the tunnel  8  is arranged directly adjacent to the reel  2 , from which the film  3  unwinds, the machine of  FIG. 3  that processes a pre-pasted film comprises means that are interposed between the reel  2  and the tunnel  8  and are adapted to facilitate removal of the film  3  from the reel in order to prepare it for the action of the tunnel. 
         [0023]    Such means comprise an arm  20 , in which the end provided with a roller  20   a  is retained, by elastic means not shown in the figure, in contact with the surface that is not pre-pasted of the film  3  in the region where the film begins to separate from the reel, and a takeup roller  21  acts on the film at the portion comprised between the arm  20  and the access to the tunnel  8 . 
         [0024]    The described invention is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent elements. 
         [0025]    The disclosures in Italian Patent Application No. MN2007A000043 from which this application claims priority are incorporated herein by reference. 
         [0026]    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.