Abstract:
A device for opening pre-glued, pre-folded sleeves into cartons. The device includes a cam wheel ( 20 ) to which are connected one or more suction arms ( 22 ). The cam wheel can be controlled to rotated at different angular velocities. A first angular velocity allows sleeves comprising a certain number of panels to be opened, and a second angular velocity allows sleeves of a different number of panels to be opened.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates to a device for the opening of pre-glued, pre-folded sleeves into cartons and more specifically, though not exclusively, to a device that includes a variable path cam, and more particularly still, though not exclusively, a variable path cam that has a controllable angular velocity. 
       BACKGROUND OF INVENTION 
       [0002]    It is known, in the field of packaging machine technology, for the opening of a pre-glued, pre-folded sleeve into a carton to be accomplished by means of a device that includes one or more suction arms fitted to a cam mechanism. Such an arrangement permits the end of each suction arm to follow a continuous, cyclic path that enables each arm to open a carton sleeve, from a flat collapsed condition as it travels along a linear conveyance means. 
         [0003]    The limitations of such devices are, however, that each cam is designed to direct each suction arm along a specific path. The path needs to be precise in order to avoid creasing of the carton and possibly complete failure of the opening process. Furthermore it is desirable to provide a cam assembly that is compatible with more than one geometry of sleeve since the number of panels of the sleeve have an impact on the path that any one panel takes as the sleeve is opened. 
         [0004]    The present invention seeks to provide a device that overcomes, or at least mitigates, this limitation such that it is compatible with sleeves comprising a differing number of panels, and with different relative arrangements of the same number of panels. 
       SUMMARY OF INVENTION 
       [0005]    A first aspect of the present invention provides a device for at least partially opening a sleeve into a carton, the device comprising a cam mechanism controlled to function at different angular velocities, the angular velocities including a first angular velocity for opening a first type of sleeve and a second angular velocity for opening a second type of sleeve, wherein the cam mechanism includes at least one suction arm and wherein the at least partial opening of the first type of sleeve is effected by causing the suction arm to be moved substantially normal to a plane in which the sleeve is disposed and wherein the at least partial opening of the second type of sleeve is effected by causing the suction arm to be moved both normal to the said plane and simultaneously along a vector corresponding to the motion of the sleeve in said plane which conveys the sleeve through the working reach of the cam mechanism. 
         [0006]    Preferably, the sleeve is guided between a surface of each rotating belt and rollers, the surface of the each belt are inclined to the said plane, and wherein the motion of a part of the sleeve along the inclined belts further opens the sleeve. 
         [0007]    Preferably, the cam wheel further comprises an internal gear and sprocket arrangement that are mechanically linked to each of the one or more suction arms, and wherein the gear and sprocket arrangement prevents the orientation of each suction arm with respect to the said plane from changing as the cam wheel rotates. 
         [0008]    Preferably, a panel of the sleeve is retained in substantially coplanar contact with the topmost surface of the conveyance means. 
         [0009]    Preferably, a vacuum seal is formed between one or more of the suction arms and one of the panels of the, wherein suction arm heads are located on the terminal end of one or more of the suction arms, and wherein the suction arm heads are brought into contact with the panel of the sleeve. 
         [0010]    Alternatively, the cam mechanism comprises a cam wheel, conveyance means and a belt system, the cam wheel being controlled to function at the said different angular velocities, wherein the at least one suction arm is attached to the cam wheel, the cam wheel comprising an internal gear and sprocket arrangement that is mechanically linked to each of the one or more suction arms, and wherein the gear and sprocket arrangement prevents the orientation of each suction arm with respect to the said plane from changing as the cam wheel rotates. 
         [0011]    Alternatively, the cam mechanism comprises a cam wheel, conveyance means and a belt system, the cam wheel being controlled to function at the said different angular velocities, the at least one suction arm being attached to the cam wheel, wherein peripheral portions of each sleeve are guided between topmost surfaces of rotating belts and rollers, the top most surface of the belts being inclined to the said plane, and wherein the motion of a part of each sleeve up the inclined belts further opens that sleeve. 
         [0012]    A second aspect of the invention provides a packaging machine having an opening mechanism as referred to in any of the of the preceding paragraphs. 
     
    
     
       BRIEF DESCRIPTION OF FIGURES 
         [0013]    Exemplary embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
           [0014]      FIG. 1  illustrates 3-dimensional view of a device including a cam assembly and associated elements according to a preferred embodiment of the present invention, 
           [0015]      FIG. 2  illustrates a side view of the device of  FIG. 1  wherein the suction arm is attached to a flat sleeve for a hexagonal carton, 
           [0016]      FIG. 3  illustrates a side view of the cam assembly of  FIG. 1  wherein the suction arm has partially opened the sleeve for a hexagonal carton, 
           [0017]      FIG. 4  illustrates a side view of the device of  FIG. 1  wherein the uppermost edges of the partially opened sleeve are fed into a belt and roller assembly, 
           [0018]      FIG. 5  illustrates a side view of the device of  FIG. 1  wherein the suction arm is attached to a flat sleeve for a rectangular carton, 
           [0019]      FIG. 6  illustrates a side view of the device of  FIG. 1  wherein the suction arm has partially opened the sleeve for a rectangular carton, 
           [0020]      FIG. 7  illustrates a side view of the device of  FIG. 1  wherein the uppermost edges of the partially opened sleeve are fed into a belt and roller assembly, and 
           [0021]      FIG. 8  illustrates the location of a second suction arm of a cam assembly according to the preferred embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]      FIG. 1  shows a 3-dimensional view of a device  10  including a cam wheel  20  according to a preferred embodiment of the present invention. It is envisaged that the preferred embodiment could be utilised as a carton erection device in a packaging system.  FIG. 1  shows the cam wheel  20 , to the front face of which may be mounted a plurality of—in this preferred embodiment, three—suction arms  22 , only one of which is illustrated for enhanced clarity. Also illustrated is a sleeve  60 , composed of six panels hinged one to another, intended for being opened into a carton of hexagonal cross section. 
         [0023]    Illustrated are two suction arm heads  30 , mounted on the lowermost ends of the suction arm  22  and capable of forming a vacuum seal between the suction arm  22  and a flat surface. Suction arm  22  is shown at its lowermost point at which the respective suction arm heads  30  have been brought into contact with a panel of sleeve  60 , forming a vacuum seal between the suction arm  22  and the said panel. The sleeve  60  is travelling tangentially to the cam wheel  20  along a conveyance means  28 . The specific arrangement and number of suction arm heads  30  are considered unessential to the core inventive concept of the present invention and may be altered from the arrangements illustrated for a preferred embodiment without parting from the spirit of the invention. This is further exemplified by the adoption of an alternative arrangement of suction head  30  in  FIG. 8 . 
         [0024]    Also illustrated in  FIG. 1  are belt systems  24  and a plurality of rollers  26 . Each belt system  24  includes an uppermost surface that follows a two stage incline away from a plane composed of the topmost surface of the conveyance means  28 . The two stage incline comprises of a first stage that is at a first angle to the plane, and a second stage that is at a second, smaller angle to the plane than the first angle. The arrangement of the rollers  26  is such that the bottommost point of the periphery of each roller  26  substantially comes into contact with the topmost surface of a respective belt  24 . 
         [0025]    The belt  24  comprises a guide  32  for accepting portions of a sleeve  60  as it moves along the conveyance means  28 . Further details relating to this feature are included below. 
         [0026]      FIGS. 2 ,  3  and  4  illustrate three points during the process of partially opening the sleeve  60 . 
         [0027]      FIG. 2  illustrates the start point of the process, and is equivalent to the arrangement described above in relation to  FIG. 1 . The suction arm heads  30  have formed a vacuum seal between the suction arm  22  and a panel of sleeve  60 . 
         [0028]      FIG. 3  illustrates the device  10  after having partially opened the sleeve  60 . Lower peripheral portions of the sleeve  60  are retained under rails, not shown, running along side the conveyance means  28 . The lower peripheral portions are hinged to edges of another panel, forming the base of the sleeve  60 , which will be lowermost after the device  10  has opened the carton. The edges of the base panel to which the lower peripheral portions are hinged are those edges that are transverse to the direction of motion of the sleeve. The presence of the rails ensures that the base panel of the sleeve  60  remains in contact with the conveyance means  28  which the suction arm partially opens the sleeve  60 . 
         [0029]      FIG. 3  further illustrates how the cam wheel  20  has rotated such that the suction arm  22  has been displaced both in the direction of the motion of the topmost surface of the conveyance means  28 , and also some distance normal to the plane comprising the topmost surface of the conveyance means  28 . A gearing system within the cam wheel  20  is employed to ensure that the suction arm  22  remains in the same orientation as the cam wheel  20  rotates. In this manner, the said panel, of sleeve  60 , that is in contact with the suction arm heads  30 , is maintained substantially parallel to a plane comprising the topmost surface of the conveyance means  28 . Thus, the path of the suction arm heads  30  results in the said panel being moved away from, whilst remaining parallel to the plane comprising the topmost surface of the conveyance means  28 . The design of the device  10  is such that the said panel of the sleeve  60  remains in substantial vertical alignment with a given point on the topmost surface of the conveyance means  28 , whilst attached to one of the suction arms  22 . The motion of the panel relative to the said given point is therefore substantially normal to the plane comprising the topmost surface of the conveyance means  28 . 
         [0030]      FIG. 3  also illustrates the point at which peripheral portions of the said panel, located along either side of the said panel transverse to the direction of motion of the topmost surface of the conveyance means  28 , are guided, by guides  32 , between the rollers  26  and the belts  24 . The peripheral portions are hinged to the said panel and are of sufficient structural integrity that the said panel may be orientated, and the entire sleeve transported, by the incline and motion of a topmost surface of the belts  24 . As the sleeve  60  is guided between the belt  24  and the rollers  26 , the said panel is released from the vacuum seal with the suction arm  22 . 
         [0031]      FIG. 4  illustrates the way in which the rotary action of the belt  24  maintains the linear motion of sleeve  60  after it has reached a terminal end of conveyance means  28 . The lower peripheral portions are still retained by rails, which extend beyond the terminal end of the conveyance means  28  for the full length of the belt system  24 . The incline of the belt  24  achieves the effect of further separating the said panel and said another panel such that the sleeve  60  becomes increasingly opened. At the point whereby the peripheral portions of the said panel reach the terminal end of the belt the sleeve  60  is substantially fully opened and can be passed on to another device within the packaging system such as, for example, article loading apparatus. 
         [0032]      FIGS. 5 ,  6  and  7  illustrate three points during the process of partially opening a sleeve  70  that is formed of four panels each hinged one to the next. The geometry of sleeve  70  means that, in order to be opened into a carton of rectangular cross section, the panel with which the suction arm heads  30  form a vacuum seal is required to pass through a different path to that required in order to open sleeve  60 . Such an alteration in the path is not possible by previously known devices that rely upon cam wheels. The preferred embodiment of the present invention makes such an alteration possible by employing an electrically powered cam wheel of variable rotational speed. When considering the cyclic motion of the suction arm  22  about the cam wheel  20  from a point of reference on the topmost surface of the conveyance means  28 , it can be appreciated that the speed of the cam wheel  20  will effect alteration in the path of the suction arm  22  and therefore the said panel of the sleeve  70 . 
         [0033]      FIG. 5  illustrates the start point of the process. The suction arm heads  30  have formed a vacuum seal between the suction arm  22  and a panel of sleeve  70 . Sue to the different in the geometry of sleeve  70  in comparison to sleeve  60 , the panel with which the vacuum seal is made is in a different position to that with which a vacuum seal would have been made had the sleeve been of the geometry of sleeve  60  of  FIG. 1 . In the case of sleeve  70 , the panel with which a vacuum seal is formed is the first of two uppermost panels to pass along the conveyance means. 
         [0034]      FIG. 6  illustrates the device  10  after having partially opened the sleeve  70 . Lower peripheral portions, or lower end closure panels, of the sleeve  70  are retained under rails running along side the conveyance means  28 . The lower end closure panels are hinged to edges of a bottom panel of the sleeve  70 , which will be lowermost after the device  10  has opened the carton. The presence of the rails ensures that the lowermost panel of the sleeve  70  remains in contact with the conveyance means  28  as the suction arm  22  partially opens the sleeve  60 . The cam wheel  20  has rotated such that the suction arm  22  has been displaced both in the direction of the motion of the topmost surface of the conveyance means, and also some distance normal to the plane comprising the topmost surface of the conveyance means  28 . A gearing system within the cam wheel  20  ensures that the suction arm remains in the same orientation as the cam wheel  20  rotates. In this manner, the panel of sleeve  70  that is in contact with the suction arm heads  30  is maintained substantially parallel to the plane of the conveyance means. Thus, the path of the suction arm heads  30  results in that panel being moved away from, whilst remaining parallel to, the plane comprising the topmost surface of the conveyance means  28 . In order to partially open a carton with a configuration substantially as illustrated in  FIG. 6 , it is necessary for the panel in contact with the suction arm heads  30  to possess an appreciable velocity relative to a bottom panel of the sleeve  60  and in the direction of motion of the conveyance means  28 . This is in contrast to the process for opening the sleeve  60  of  FIG. 3  during which both the bottom panel and the panel in contact with the suction arm heads  30  are required to have the same velocity in the direction of motion of the conveyance means  28 . 
         [0035]      FIG. 6  also illustrates the point at which end closure panels, or peripheral portions of a top panel of sleeve  70 , are guided, by guides  32 , between the rollers  26  and the belts  24 . The end closure panels are preferably hinged to the top panel of sleeve  70  and are of sufficient structural integrity that the top panel may be orientated, and the entire sleeve transported, by the incline and motion of a topmost surface of the belts  24 . As the sleeve  70  is guided between the belt  24  and the rollers  26 , the said panel is released from the vacuum seal with the suction arm  22 . 
         [0036]    It is advantageous that as large a proportion of the top panel (including its peripheral portions) of the sleeve are supported at the point that the vacuum seal with the suction arm  22  is released. It is therefore contemplated that a secondary belt system, parallel with the conveyance means and offset therefrom, may be provided to enhance the robustness of the above system. Such secondary belts could provide a surface upon which the aforementioned peripheral portions of the top panel may be disposed, and which could rotate to provide additional driving force for passing the peripheral portions between the roller  26  and the belts  24 . A further feature of may be the provision of an articulated guide at the head of such a secondary belt system that would initially be disposed in a lowered configuration and thereby assist in raising the level of the peripheral portions and, as a result, the top panel. Once the leading edge of the top panel has passed over the articulated guides, they could be controlled to be repositioned to an elevated configuration, thereby supporting the remainder of the peripheral portions of the top panel. Additionally or alternatively, an air blower may be place proximate the start of the belts  24 , and could blow a stream of air upward toward an underside of the top panel of the sleeve  70 , thereby assisting to maintain the sleeve  70  in a semi erected condition as it passes between the rollers  26  and the belts  24 . 
         [0037]      FIG. 7  illustrates the way in which the rotary action of the belt  24  maintains the linear motion of the sleeve  70  after it reaches a terminal end of the conveyance means  28 . The lower peripheral end closure panels of sleeve  70  are still retained by rails, which extend beyond the terminal end of the conveyance means  28  for the full length of the belt system  24 . The incline of the belt  24  achieves the effect of further separating the top panel and bottom panels such that the sleeve  70  becomes increasingly opened. At the point where the sleeve  70  reaches the terminal end of the belt it is substantially in a fully opened condition, and can be passed on to another device within the packaging system such as, for example, article loading apparatus. 
         [0038]      FIGS. 1 to 7  each illustrate only one of the suction arms  22  connected to the cam wheel  20 , for enhanced clarity. 
         [0039]    Turning to the invention in general, it will be understood that it is possible to employ multiple suction arms  22 , the maximum number being determined by the size of the sleeves  60 / 70  and the desired throughput capacity of the device. 
         [0040]      FIG. 8  illustrates a preferred embodiment of the present invention in which two suction arms  22  are controlled by cam wheel  20 . It is envisaged that any number of suction arms may be employed without departing from the spirit of the invention. 
         [0041]    It is contemplated to be within the scope of the present invention, as defined by the claims, that the device may form a sub assembly of a larger packaging machine that offers further functionality in respect of packaging articles such as cans or bottles, within the erected cartons. 
         [0042]    References to directional features such as ‘top,’ ‘bottom,’ ‘topmost,’ ‘uppermost’ and ‘lowermost’ serve only to differentiate their respective components from one another, and should not be seen as limiting those respective components to a particular orientation; it will be understood that other embodiments may be used in which such directional features are altered without departing from the scope of the present invention. For example, the entire device could theoretically be mounted vertically, with suitable adjustment of the conveyance means, such that the sleeve  60 / 70  could no longer be described as being placed upon a topmost surface of the conveyance means; it is envisaged that such an embodiment would, however, clearly still fall within the scope of the present invention. 
         [0043]    It will further be understood that references to “cam,” “cam mechanism” and “cam wheel” are meant as illustrative descriptors only, and do not limit their respective components to any particular configuration.