Abstract:
A labeling unit having a vertically displaceable motor, a vertically displaceable upper cover plate for a pallet drum as well as a shift linkage which couples the upper cover plate to the motor such that, when the motor is displaced upwards, the pallet drum is lifted together therewith. The motor and the cover plate can thus be lifted in an ergonomically advantageous manner by means of a common operating mechanism on the comparatively easily accessible motor, when a change of format is executed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority to German Application No.102013212126.1, filed Jun. 25, 2013. The priority application, DE 102013212126.1, is hereby incorporated by reference. 
       FIELD OF THE DISCLOSURE 
       [0002]    The present disclosure relates to a labeling unit for containers, in particular a cold-glue labeling unit. 
       BACKGROUND 
       [0003]    On filling lines for beverage bottles or the like, a change of label formats normally necessitates an exchange of the gluing drums and gluing pallets of cold-glue labeling units. To this end, it is first necessary to lift, e.g. on pallet drums, an upper cover plate with bearings for the gluing pallet shafts, so that the gluing pallets can then be removed from the pallet drum with their drive shafts. Lifting the cover plate is, however, often difficult, since the pallet drum is not fully accessible to the operator and since, due to the tight fit tolerances demanded, the cover plate can only be removed upwards with substantial expenditure of energy. 
         [0004]    In comparison with conventional shaft-hub connections, it proved to be advantageous to couple the gluing drum such that it can be removed from the labeling unit to the side, so that the gluing drum can be exchanged. The comparatively heavy gluing drum is then manually removed, e.g. from an upper shaft end of the drive unit positioned therebelow, by pulling it off upwards, and taken out to the side. The manual lifting of the gluing drum is, however, still unfavorable from an ergonomic point of view. 
         [0005]    Hence, there is a need for a labeling unit which allows gluing drums and/or gluing pallets to be exchanged under improved ergonomic conditions and with little expenditure of time. 
       SUMMARY OF THE DISCLOSURE 
       [0006]    The posed task is solved by a labeling unit comprising a gluing drum; a vertically displaceable motor for driving the gluing drum; a pallet drum with an upper cover plate that is adapted to be lifted upwards; and a shift linkage by means of which the cover plate is coupled to a housing section of the motor such that, when the motor is displaced upwards, the cover plate is lifted together therewith. 
         [0007]    The cover plate is preferably configured for supporting gluing pallet shafts. This means that gluing pallet shafts provided in the pallet drum have their upper ends rotatably supported in/on the cover plate. For retrofitting the labeling unit, the upper ends of the gluing pallet shafts can be exposed such that it is possible to remove the gluing pallet shafts with the gluing pallets. Through the connection of the cover plate according to the present invention, the cover plate can be raised with the aid of the shift linkage on the output side, especially with a straight vertical lift movement. When the cover plate is lowered and thus ready for operation, the gluing drum and the pallet drum cooperate with a gripper cylinder in the usual way. 
         [0008]    Preferably, the shift linkage is configured such that the upper cover plate can be raised from a lower operating position for supporting gluing pallet shafts to an upper retrofitting position for exchanging the gluing pallet shafts. During lifting and decoupling of the motor from the gluing drum, the cover plate can be raised to such an extent that bearings provided on the cover plate can be pulled off the gluing pallet shafts, whereby the latter are released. The exchange of the gluing drum and the gluing pallets will then only necessitate a lift movement on the comparatively easily accessible motor. In the lower operating position of the cover plate, the pallet shafts are rotatably supported in/on the cover plate in a manner known per se. 
         [0009]    Preferably, the shift linkage comprises a first rotary bolt, which is coupled to the motor so as to convert a stroke (lift movement) of the motor into a rotary movement of the shift linkage. The conversion into a rotary movement facilitates the support of the shift linkage, the transmission of forces to the cover plate and a possibly desired lift transmission ratio. In particular a rotation about a shaft axis orthogonal to the stroke (lift movement) of the rotary bolt is of advantage. The torque can thus be transmitted more easily in a lateral direction into an area above the upper cover plate. 
         [0010]    The first rotary bolt has preferably formed thereon a switching roller which engages a guide groove formed on the motor. The guide groove can be formed on a housing section of the motor as a control curve of adequate shape with little manufacturing effort. The shape of the guide groove can be adapted in a flexible manner to a desired conversion movement of the rotary bolt and the lift movement executed by the motor. 
         [0011]    The shift linkage preferably comprises a second rotary bolt which is coupled to the cover plate so as to convert the rotary movement of the shift linkage into a stroke (lift movement) of the upper cover plate. The torque can thus easily be converted into a lifting force. The torque can be transmitted e.g. with the aid of a shaft supported on the motor in a stationary manner. 
         [0012]    The first and the second rotary bolts preferably differ from one another with respect to effective lever lengths and/or absolute rotary positions of the levers. A lift transmission ratio from the first rotary bolt to the second rotary bolt can be accomplished in this way. 
         [0013]    The effective lever lengths and/or the absolute rotary positions of the levers will then preferably differ such that the second rotary bolt executes a stroke (lift movement) that is smaller than that of the first rotary bolt. The stroke (lift movement) of the upper cover plate required for an exchange of the gluing pallets is normally smaller than the stroke (lift movement) of the motor required for an exchange of the gluing drum. The force for lifting the upper cover plate that is necessary at the first rotary bolt can be reduced by transmitting the lift movements. 
         [0014]    The second rotary bolt is preferably coupled to the upper cover plate by means of vertically guided lifting rods. The vertical lifting force can be transmitted to the cover plate in this way. The upper cover plate can thus be lifted more easily in the axial direction of the pallet drum. 
         [0015]    According to a preferred embodiment, the second rotary bolt can be pushed beyond a reversal point such that, at a lower reversal point, at which the cover plate is at a lower operating position, the lifting rods change from a downward directed partial stroke (negative partial lift movement) to an upward directed partial stroke (positive partial lift movement). In other words, the cover plate can first be pushed fully downwards, down to and into the operating position, by the downward directed partial stroke, and then the lifting rods can be mechanically decoupled from the cover plate, which rotates during operation, by the upward directed partial stroke. The reversal point of the lift movement can be created by a suitable lever position of the second rotary bolt relative to the lever position of the first rotary bolt. At the lower operating position of the motor, the two levers will then preferably define respective acute angles with opposite signs with the vertical. 
         [0016]    Preferably, the upper cover plate has secured thereto a switching disk, which is coaxial with respect to the pallet drum and which is provided with a circumferentially extending groove, and the lifting rods have secured thereto switching cams engaging said groove and/or a connection flange engaging said groove so as to transmit a lifting force to the switching disk. This allows the switching cams and/or the connection flange to engage the switching disk irrespectively of the rotary position of the pallet drum and the upper cover plate. In addition, the lift movement can easily be transmitted by the switching cams and/or the connection flange to an upper contact surface of the groove. The groove may e.g. extend along a circle on the outer circumference of the switching disk and may be open in a radial direction. The groove may, however, also be open downwards, e.g. on a mushroom-shaped switching disk. The switching cams may also be replaced by switching rollers. 
         [0017]    According to a preferred embodiment, the switching cams then have a certain amount of vertical clearance in the groove, especially such that the switching cams can move freely at a lowered operating position of the upper cover plate. This will reduce or prevent wear during the operation of stationary switching cams on the switching disk, which rotates together with the pallet drum when in operation. This applies equally to connection flanges and switching cams. 
         [0018]    A particularly advantageous embodiment of the labeling unit according to the present disclosure additionally comprises a third rotary bolt for adjusting the vertical position of the motor. The motor is preferably secured in position above the gluing drum. By means of a rotary bolt, the motor can easily be lifted so as to separate a torque-transmitting connection between the motor and the associated gluing drum. In particular, a rotary bolt can be used for generating in an ergonomically advantageous manner a lifting force required for lifting the motor and the cover plate of the pallet drum by a rotary movement of an adequately dimensioned lever. 
         [0019]    According to a preferred embodiment, the third rotary bolt then comprises an eccentric with a switching roller which engages a guide groove formed on the motor. The guide groove can be formed easily on a suitable housing section of the motor, e.g. by subjecting the housing section to milling or by securing thereto a rail or the like comprising the guide groove. The eccentric may be secured to a support structure of the motor. 
         [0020]    Preferably, the third rotary bolt is formed on motor side located opposite the shift linkage. This allows an ergonomically advantageous position of the third rotary bolt. Furthermore, loads occurring on the housing sections of the motor when the third rotary bolt is operated and when the lift movement of the first rotary bolt is transmitted can thus be distributed in an advantageous manner to opposite sides of the motor and can thus be approximately balanced. 
         [0021]    According to a preferred embodiment, the motor is adapted to be displaced upwards from an operating position above the gluing drum, in particular linearly in a vertical direction. The motor is in particular displaceable upwards until it arrives at a retrofitting position for removing the gluing drum. The support of the motor above the gluing drum facilitates a removal of the gluing drum to the side, e.g. by lifting and/or tilting the gluing drum away from a splined drive coupling. The motor is then supported e.g. on a vertical linear guide. This facilitates decoupling of the motor from the gluing drum. The vertical linear guide also allows a precise force transmission of the first rotary bolt for driving the shift linkage. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0022]    A preferred embodiment of the lifting unit according to the present invention is shown in the drawing, in which: 
           [0023]      FIG. 1  shows a partial view of the labeling unit according to the present disclosure; 
           [0024]      FIG. 2  shows a partial view of the labeling unit according to the present disclosure; 
           [0025]      FIG. 3  shows a fragmentary sectional view through the labeling unit according to the present disclosure; 
           [0026]      FIG. 4  shows a partial view in the lowered condition of the motor; and 
           [0027]      FIG. 5  shows a partial view in the raised condition of the motor. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    As can be seen from  FIGS. 1 to 3 , the labeling unit  1  according to the present disclosure, which is e.g. a cold-glue labeling unit for beverage bottles or the like, comprises according to a preferred embodiment a gluing drum  2  and a motor  3  for continuously driving the gluing drum  2 . The motor  3  is supported above the gluing drum  2 . The drive torque for the gluing drum  2  is transmitted by means of a schematically outlined splined coupling  4 , which allows the gluing drum  2  to be removed, e.g. by lateral tilting, when the motor  3  has been lifted by a first stroke  5 . 
         [0029]    The labeling unit  1  additionally comprises a pallet drum  6  continuously rotatable about a vertical axis  6 ′ and provided with an upper cover plate  7  for supporting gluing pallet shafts  8  and a shift linkage  9 , which mechanically couples the upper cover plate  7  to a first housing section  3   a  of the motor  3 . The motor  3  and the pallet drum  6  are supported on a common frame  10 . The way in which the gluing drum  2  and the pallet drum  6  cooperate, when the labeling unit  1  is in operation, with components, such as gripper cylinders, used for handling the containers to be labeled and the labels is known and will not be explained in detail hereinbelow. 
         [0030]    The shift linkage  9  comprises a first rotary bolt  12  with a first lever  12   a  and a first switching roller  12   b,  which engages a first guide groove  13  formed on the motor  3 . This guide groove  13  may be configured as a recess in the first housing section  3   a  and/or secured in position on the first housing section  3   a  in the form of guide rails or the like. The first rotary bolt  12  converts the vertical first stroke  5  of the motor  3  into a rotary movement  14 . 
         [0031]    The shift linkage  9  additionally comprises a second rotary bolt  15  with a second lever  15   a  and a second switching roller  15   b,  which engages a guide groove or recess  17  formed in a yoke  16 . The first lever  12   a  and the second lever  15   a  are connected in a torque-transmitting manner by means of a shifting shaft  19  and/or a gear unit (not shown). The second rotary bolt  15  converts the rotary movement  14  into a vertical second stroke  20  of the cover plate  7 , which is preferably smaller than the associated first stroke  5  of the motor  3 . 
         [0032]    As is clearly shown in particular in  FIG. 3 , the yoke  16  has secured thereto two lifting rods  21  that are linearly guided in the vertical direction. At the lower end of each lifting rod  21  a respective switching cam  22  is formed for transmitting an upwardly directed lifting force to a switching disk  24  which is fixedly connected to the cover plate  7 . Also switching rollers, which are supported such that they are rotatable about a horizontal axis, (not shown) or a circumferentially extending connection flange  23 , which is schematically outlined in  FIG. 2 , may be formed as elements that correspond functionally to the switching cams  22 . 
         [0033]    The upper cover plate  7  is shown in a lower operating position  27 , at which the pallet shafts  8  are supported in the cover plate  7 . According to the present disclosure, the cover plate  7  can be raised by the second stroke  20  to an upper retrofitting position  28  above the pallet shafts  8  so that the pallet shafts  8  can be removed for replacing gluing pallets secured thereto. At the lower operating position  27  the pallet drum  6  cooperates with a label gripper cylinder (not shown) in the usual way. 
         [0034]    The substantially cylindrical switching disk  24  has formed therein a circumferential groove  25 , which opens radially outwards and which can be engaged by the switching cams  22  and/or the connection flange  23  from the side, irrespectively of the rotary position of the switching disk  24 . The groove  25  is preferably higher than the switching cams  22  and/or the connection flange  23 , so that said switching cams  22  and/or connection flange  23  have a certain amount of vertical clearance in the groove  25  in the lowered condition of the cover plate  7 . When the cover plate  7  and the switching disk  24  fixedly connected thereto have been fully lowered to the lower operating position  27 , the switching cams  22  and/or the connection flange  23  are preferably not in contact with the inner wall of the groove  25 . The switching cams  22  and/or the connection flange  23  will then freely circulate in the groove  25  during normal operation of the pallet drum  6 , so as to prevent wear of the switching cams  22 , the connection flange  23  and the groove  25 . 
         [0035]    During normal operation of the pallet drum  6 , the pallet drum  6  rotates together with the upper cover plate  7  and the switching disk  24 , whereas the switching cams  22 , the shift linkage  9 , the yoke  16  and the guide rods  21  have a constant rotary position. When the upper cover plate  7  is lifted, the switching disk  24  is suspended from the switching cams  22  and/or the connection flange  23 . 
         [0036]    The motor  3  is supported on linear units  31  such that it is displaceable in a vertical direction. With the aid of a third rotary bolt  32 , the motor  3  can be raised from a lower operating position  33  to an upper retrofitting position  34  for removing the gluing drum  2 . In the course of this movement, the motor  3  and the third rotary bolt  32  execute the first stroke  5 . The shift linkage  9  preferably causes the first stroke  5  to be converted into a smaller second stroke  20 . The operating force required for raising the upper cover plate  7  is therefore smaller on the driving end of the shift linkage  9  than on the output side of the shift linkage  9 . This is due to the different effective lever lengths  12   c,    15   c  of the first and second levers  12   a,    15   a  and/or the different absolute angular positions  12   d,    15   d  of the first and second levers  12   a,    15   a.  In  FIG. 3  this is outlined schematically. 
         [0037]    The relative angular position of the first and second levers  12   a,    15   a  additionally causes an inversion of direction of the guide rods  21  and of the switching cams  22  at a lower reversal point of their lift movement, at which the cover plate  7  has been lowered by the second stroke  20  down to the lower operating position  27 . The lifting rods  21  then execute first a downward directed partial stroke  21   a  for pushing the cover plate  7  fully into its operating position  27  and, subsequently, an upward directed partial stroke  21   b  so as to eliminate the force fit connection between the switching cams  22  and/or connection flange  23  and the switching disk  24 . To this end, the switching cams  22  are positioned in a suitable manner within the certain amount of clearance in the guide groove  25 . To make things clearer, the partial strokes  21   a,    21   b  are not drawn to scale. 
         [0038]    The mode of operation of pushing the second rotary bolt  15  beyond the reversal point, at which the second lever  15   a  is directed vertically downwards, can be seen in  FIG. 3 . This figure shows the no-load position of the lifting rods  21  after pushing beyond the reversal point in an anti-clockwise direction. Lifting of the motor  3  from this position causes a clockwise rotation of the second lever  15   a  first down to the lower reversal point of the lifting rods  21 , corresponding to the dead center of the shift linkage  9 , and subsequently a lift movement of the lifting rods  21  and of the cover plate  7  suspended therefrom. Hence, lifting as well as pressing-on of the cover plate  7  and the subsequent relief of the lifting mechanism on the output side are caused by the lift movement of the motor  3  alone. At the no-load position shown, the first and second levers  12   a ,  15   a  each define with the vertical a respective acute angle  12   d,    15   d  with opposite signs. This is symbolized by oppositely directed arrows  12   d,    15   d  in  FIG. 3 . 
         [0039]    The shifting shaft  19  of the shift linkage  9  is supported e.g. in a bearing block  35 , which is fixedly connected to the support frame  10 , such that it is rotatable about a horizontal axis of rotation  19 ′. The third rotary bolt  32  is preferably formed on a second wall section  3   b  of the motor  3 , said second wall section  3   b  being located on the opposite side of the first rotary bolt  12 . In correspondence with the first guide groove  13 , the second housing section  3   b  has formed therein/thereon a second guide groove  36  for the third rotary bolt  32 . This is schematically outlined in  FIGS. 4 and 5 . 
         [0040]      FIG. 4  illustrates the mode of operation of the third rotary bolt  32  during lifting of the motor  3 .  FIG. 4  shows the motor  3  at the lower operating position  33 , and  FIG. 5  shows it at the upper retrofitting position  34 . According to these figures, the third rotary bolt  32  comprises an eccentric  37  having supported thereon a third switching roller  38 . This switching roller  38  engages the second guide groove  36  of the motor  3 . Rotating the eccentric  37  by means of an operating lever  39 , in the present example by approx.  180 ° , leads to the change in position of the motor  3  between the lower operating position  33  and the upper retrofitting position  34 . In addition, the third rotary bolt  32  may have provided thereon spring elements  40 , which push the motor  3  e.g. downwards so as to keep the connection to the gluing drum  2  in a preloaded condition and/or so as to arrest the motor  3  at the upper retrofitting position  34  by pushing the eccentric  37  beyond a dead center. 
         [0041]    Instead of the different effective lever lengths  12   c,    15   c  and/or the absolute rotary positions  12   d,    15   d  of the first and second levers  12   a,    15   a  of the shift linkage  9 , or in addition thereto, a transmission ratio of the shift linkage  9  may be realized by means of interengaging shifting shafts  19  on the bearing block  35 . 
         [0042]    The third rotary bolt  32  may be replaced or supplemented by other displacement means for lifting the motor  3 . Imaginable are toggle levers, threaded spindles or the like. The displacement means for the motor  3  may also be driven electrically, pneumatically or the like. The decisive aspect is that a drive acting on the upper cover plate  7  can be produced with the aid of the shift linkage  9  according to the present disclosure so as to lift the motor  3  and the cover plate  7  synchronously by means of a single manual drive or motor drive. Furthermore, the cover plate can be fully pressed on by lowering the motor  3  onto the pallet drum  6  and, when a dead center of the shift linkage  9  has been exceeded, the lift movement of the guide rods  21  carrying the cover plate  7  can be reversed and the connection between the shift linkage  9  and the cover plate  7  mechanically relieved.