Abstract:
The present invention relates to a transfer apparatus for transfer to and/or from a processing machine, in particular an internal lacquering machine, for processing cylindrical containers with or without a closed bottom, in particular made of aluminium or steel, wherein the processing machine comprises a holding dial provided with holding elements for holding the cylindrical containers, to a processing system including such transfer apparatus and to a corresponding transfer method and it is an object of the present invention to provide such transfer apparatus, which allows for transferring cylindrical containers with or without a closed bottom to a processing machine the holding elements of which having radially and tangentially fixed positions relative to the holding dial and being equally distributed with a first mutual pacing on a circle with a reduced need for maintenance and/or cleaning.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 USC §119 to European Patent Application No. 13170139.3 filed on May 31, 2013 and European Patent Application No. 13174473.2 filed on Jul. 1, 2013. Both applications are hereby incorporated by reference in their entirety. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a transfer apparatus for transfer to and/or from a processing machine, in particular an internal lacquering machine, for processing cylindrical containers with or without a closed bottom (e.g. cans or cylindrical tubes or pipes), in particular made of aluminium or steel, wherein the processing machine comprises a holding dial provided with holding elements for holding the cylindrical containers, to a processing system including such transfer apparatus and to a corresponding transfer method. 
       BACKGROUND OF THE INVENTION 
       [0003]    A transfer device according to EP 1 132 207 A1 comprises a rotating transfer rotor for transferring hollow bodies to a spindle plate arranged on a printing machine, and holding devices arranged on the transfer rotor and defining receiving sites for the hollow bodies. The hollow bodies are transferred between the receiving sites of the holding devices of the transfer rotor and the receiving spindles of the spindle plate, wherein the corresponding trajectories thereof desired for the transfer are achieved by radially displacing both, the receiving spindles and the receiving sites. 
         [0004]    DE 10 2011 081 590 A1 discloses a compact can transfer system having holding units and mandrel and transfer wheels rotationally driven around rotational axes that are parallel to each other, where a distance of one of the holding units is varied from minimum distance to maximum distance from rotational axis of the mandrel wheel. The other holding unit is pivotally fastened to the transfer wheel around a pivotal axis by a transfer swivel arm, where the pivotal axis extends parallel to the rotational axis of the transfer wheel and includes fixed distance from the rotational axis for each holding unit. 
         [0005]    Such arrangements, however, are limited to processing machines which allow for a displacement of the receiving spindles, holding units or corresponding components at least in a radial way. 
         [0006]    There is also a need for transferring cylindrical containers with or without a closed bottom to a processing machine the holding elements of which having radially and tangentially fixed positions relative to the holding dial and being equally distributed with a first mutual pacing on a circle. 
         [0007]    Conventionally, cylindrical containers, for example for being internally lacquered, are transferred to such processing machines (e.g. internal lacquering machines) by means of chain conveyors. Such chain conveyors are, however, dissatisfactory in that they are in high need of maintenance and tend to contaminate the processing machines, e.g. due to grease needed for operation. 
       SUMMARY OF THE INVENTION 
       [0008]    It is an object of the present invention to provide a transfer apparatus as indicated above, which allows for transferring cylindrical containers with or without a closed bottom to a processing machine the holding elements of which having radially and tangentially fixed positions relative to the holding dial and being equally distributed with a first mutual pacing on a circle with a reduced need for maintenance and/or cleaning. 
         [0009]    In a first aspect of the present invention a transfer apparatus for transfer to and/or from a processing machine, in particular an internal lacquering machine, for processing cylindrical containers with or without a closed bottom, in particular made of aluminium or steel, wherein the processing machine comprises a holding dial provided with holding elements for holding the cylindrical containers, the holding elements having radially and tangentially fixed positions relative to the holding dial and being equally distributed with a first mutual pacing on a circle is presented, the transfer apparatus comprising: a plurality of transfer elements arranged on a transfer rotor, wherein each transfer element has a mounting axis perpendicular to the transfer rotor, the mounting axis extending through a mounting point of the transfer element on the transfer rotor, and a holding position of a held cylindrical container, wherein each transfer element is arranged for changing a distance between the mounting point and the holding position, wherein each transfer element is further pivotally arranged on the transfer rotor for being pivoted around the mounting axis, wherein the transfer apparatus is arranged, upon rotating the transfer rotor, for changing the distance between the mounting point and the holding position of a transfer element together with pivoting the transfer element such that a path of the holding position coincides with a path of a holding position of a corresponding holding element of the processing machine. 
         [0010]    A further aspect of the present invention provides a processing system for cylindrical containers with or without a closed bottom, in particular made of aluminium or steel, comprising: a processing machine for processing the cylindrical containers, wherein the processing machine comprises a holding dial provided with holding elements for holding the cylindrical containers, the holding elements having radially and tangentially fixed positions relative to the holding dial and being equally distributed with a first mutual pacing on a circle, and at least a transfer apparatus according to the present invention for transferring the cylindrical containers to and/or from the holding dial of the processing machine. 
         [0011]    In a yet further aspect of the present invention a transfer method for transfer to and/or from a processing machine, in particular an internal lacquering machine, for processing cylindrical containers with or without a closed bottom, in particular made of aluminium or steel, is presented, wherein the processing machine comprises a holding dial provided with holding elements for holding the cylindrical containers, the holding elements having radially and tangentially fixed positions relative to the holding dial and being equally distributed with a first mutual pacing on a circle, the transfer method comprising: rotating a transfer rotor having a plurality of transfer elements, each transfer element having a mounting axis perpendicular to the transfer rotor, the mounting axis extending through a mounting point of the transfer element on the transfer rotor, and a holding position of a held cylindrical container, each transfer element being arranged for changing a distance between the mounting point and the holding position and being further pivotally arranged on the transfer rotor for being pivoted around the mounting axis, wherein the method further comprises, upon rotating the transfer rotor, changing a distance between the mounting point of a transfer element on the transfer rotor and the holding position together with pivoting the transfer element around the mounting axis, wherein the changing of the distance and the pivoting are provided such that a path of the holding position coincides with a path of a holding position of a corresponding holding element of the processing machine, wherein a cylindrical container is transferred between being held by the holding element and by the transfer element during the coinciding of the paths of the holding positions. 
         [0012]    According to another aspect of the present invention a software product for controlling a transfer apparatus for transfer to and/or from a processing machine for cylindrical containers with or without a closed bottom is provided, the software product comprising program code means for causing a transfer apparatus to carry out the steps of the method according to the present invention when the software product is run on a transfer apparatus according to the present invention. 
         [0013]    It shall be understood that the transfer apparatus of claim  1 , the processing system of claim  9 , the processing arrangement of claim  13 , the transfer method of claim  14  and the computer program of claim  15  have similar and/or identical preferred embodiments, in particular, as defined in the dependent claims. 
         [0014]    It shall be understood that a preferred embodiment of the invention can also be any combination of the dependent claims or above embodiments with the respective independent claim. 
         [0015]    These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    In the following drawings: 
           [0017]      FIG. 1  shows an overview in front sight of a processing system in accordance with an embodiment of the invention, 
           [0018]      FIG. 2  shows a perspective, partial cross section view of a transfer apparatus in accordance with an embodiment of the invention, 
           [0019]      FIG. 3  shows another partial perspective view of a transfer apparatus in accordance with an embodiment of the invention, 
           [0020]      FIG. 4  shows a schematic illustration of a processing arrangement in accordance with an embodiment of the invention, 
           [0021]      FIG. 5  shows a schematic flow diagram illustrating the transfer method in accordance with an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]      FIG. 1  shows an overview in front sight of a processing system  1  in accordance with an embodiment of the invention. 
         [0023]    The processing system  1  is provided with an accumulator  2  of a production line for cans  100  (as an example of a cylindrical container with a closed bottom). Arranged next to the accumulator  2  there is a loading transfer apparatus  3  in the form of a vacuum loading star, which is arranged for transferring cans received from the accumulator  2  to the processing machine  4 . For unloading the processing machine  4 , there is provided an unloading transfer apparatus  5 , which in turn is arranged next to an unloading portion  6  connected to the remainder of the production line (not shown). 
         [0024]    The processing machine  4 , in this case an internal lacquering machine  4 , has a holding dial  7  provided with holding element or gripper  8  for holding the cans  100  and a lacquering portion  9  in which the internal lacquering of the cans  100  is provided. In general, the arrangement of the internal lacquering machine corresponds to conventional lacquering machines, so that a detailed description thereof may be omitted. However, differing from conventional lacquering machines, the lacquering portion  9  is provided in the lower part of the lacquering machine  9 , which give the benefit that remains of oversprayed paints may be removed more easily. 
         [0025]    In contrast to conventional systems, according to the present invention, the transfer loading and unloading is not done by means of a chain conveyor feeding to the gripper of the processing machine. In the described embodiment both, the loading and the unloading, are provided by means of transfer apparatuses  3 ,  5  according to the invention. However, the invention is not limited to such arrangement and it is also possible to provide the transfer apparatus only on the loading or on the unloading side, while otherwise conventional methods and means for unloading or loading are employed. 
         [0026]    The loading transfer apparatus  3  includes a plurality of transfer elements  10  arranged on a transfer rotor  11 . Each transfer element  10  has a mounting axis  12  (only partially shown). The mounting axes  12  of the plurality of transfer elements  10  each have a position fixed with respect to the transfer rotor  11 , wherein these positions are equally distributed with a second mutual pacing on a circle, the center of which coincides with the center of the transfer rotor  11 . Each transfer element  10  is arranged for changing a distance between the respective position of the mounting axis  12  and a respective holding position  13  at which the transfer element  10  holds a can  100  during the transfer process. Further, the transfer elements  10  may be pivoted around the mounting axis  12 . 
         [0027]    Accordingly, the transfer elements  10  allow for a movement of the holding positions  13  with respect to the transfer rotor  11  in a radial direction (by changing the distance to the mounting axis  12 ) as well as in a tangential direction (by pivoting the transfer elements  10  around the mounting axis  12 ). 
         [0028]    The combination of these movements, which in the present embodiment are caused by an arrangement of cams and cam followers (see below), ensure that the path of a can  100  (or its holding position  13 ) during a clockwise rotation of the transfer rotor  11  corresponds to that of a respective holding element or gripper  8  (during a counter-clockwise rotation of the holding dial  7 ) for a sufficiently long period to transfer the can  100  from being held by the transfer element  10  to being held by the gripper  8 . During this period, the cans  100  are respectively pushed axially (i.e. along the long axis of the can which is parallel to the mounting axis  12  of the transfer element  10 ) into the retaining grippers  8  that are placed on the transport plate or holding dial  7  of the machine. 
         [0029]    In the illustrated embodiment, a corresponding combination of radial and tangential (or pivotal) movement is also provided for the transfer of cans  100  from the accumulator  2  to the transfer apparatus  3 , i.e. for the receiving of the cans by the transfer elements  10  from the vacuum drum of the accumulator  2 , even though other—conventional—methods for effecting such transfer may be used as well. 
         [0030]    According to the present invention, the distance between the holding positions  13  where the cans  100  are placed is variable during rotation of the transfer rotor  11  (and the simultaneous rotation of the holding dial  7  or the vacuum drum of the accumulator  2 ) in order to adapt to the distance that the cans have on the vacuum drum of the accumulator and during the portion of angle of rotation where the transfer apparatus  3  copies the continuous movement of the holding dial  7 . 
         [0031]    The unloading of the cans  100  from the internal lacquering machine  4  by means of the unloading transfer apparatus  5  corresponds basically to the loading process, so that a further repetition of a description thereof may be omitted. However, differing from the transfer elements  10  of the loading transfer apparatus  3 , the transfer elements  10 ′ of the unloading transfer apparatus  5  are not provided for pushing a can  100  into a gripper or holding element  8  of the internal lacquering machine. It is nevertheless to be noted that also the loading transfer apparatus does not necessarily have to be provided for pushing if another (as such conventional) approach is taken for having a can taken over by the holding element or gripper  8  from the transfer element  10 . 
         [0032]      FIG. 2  shows a perspective, partial cross section view of a transfer apparatus in accordance with an embodiment of the invention. 
         [0033]    The transfer apparatus  3  is a loading transfer apparatus  3  and is provided with pushers  14  for pushing a can (not shown) held in a holding position  13  of the respective transfer element  10  to be taken over by the gripper of the processing machine (not shown). 
         [0034]    The transfer apparatus  3  includes the transfer rotor  11  on which a plurality of transfer elements  10  is mounted by means of mounting axes  12  held by the transfer rotor  11  in respective bearings  15  in such a way that the rotation axis of the transfer rotor  11  is parallel to the mounting axes  12 . Each mounting axis  12  is further provided with a cam follower  16  for following a cam  17  provided on the transfer rotor  11  for controlling an axial movement (i.e. a movement parallel to the rotation axis of the transfer rotor  11 ). Such axial movement of the mounting axis  12  results in a corresponding movement of a part of transfer element  10 . 
         [0035]    The transfer elements  10  are respectively mounted on their mounting axis  12  such a pivoting of the transfer element  10  around the mounting axis  12  is possible, wherein each transfer element  10  includes a lever arm  18  (see also  FIG. 3 ) arranged to engage in either a front groove  19  or a back groove  19  provided on the transfer rotor  11 . The engagement of the lever arm  18  (specifically a protrusion thereof) with the corresponding groove allows for a control of the pivotal position of the transfer element  10  with respect to the mounting axis  12 . 
         [0036]    Further, there is provided a further groove or cam  20  in which a cam follower or protrusion  21  of each transfer element  12  engages, wherein this arrangement allows in cooperation with bearings  22  and  23  for a radial movement of the holding position  13  with respect to the mounting axis  12  of each transfer element  10 . 
         [0037]      FIG. 3  shows another partial perspective view of a transfer apparatus in accordance with an embodiment of the invention. 
         [0038]    In particular,  FIG. 3  shows a different view of the loading transfer apparatus  3  shown in  FIG. 2 . 
         [0039]    On the transfer rotor  11  (only partially illustrated) the plurality of transfer elements  10  are provided, each having a lever arm  21  with a protrusion for engaging in the cams or grooves (not shown in  FIG. 3 , see  FIG. 2 ) of the transfer rotor  11 , allowing for and controlling a pivoting of the transfer element  10  around its mounting axis  12  and a further cam follower or protrusion  21  for allowing for and controlling a radial movement of the holding position  13  of the transfer element  10 . 
         [0040]    The lever arms  18  are provided in a staggered manner, wherein alternating a lever arm  18  is provided for engaging into the back or the front groove  19  of the transfer rotor  11 . 
         [0041]      FIG. 4  shows a schematic illustration in top view of a processing arrangement in accordance with an embodiment of the invention. 
         [0042]    The processing arrangement includes two processing systems  1  which are arranged facing each other, wherein a common operating control unit  25  is provided between the processing systems. 
         [0043]    In the illustration of  FIG. 4 , cans to be processed are provided by means of feeding units  23  from the left, while processed cans are transported from the processing systems  1  by means of receiving units  24  to the right. Thus, there is a common upstream direction (here: from the left) and a common downstream direction (here: to the right) for the two processing systems. 
         [0044]    Due to the processing systems  1  facing each other, control and supervision of these systems may be done simultaneously for both systems from the common operating control unit  25 . 
         [0045]    The two processing systems  1  of this embodiment are constructed in basically the same manner and nevertheless allow for being loaded from the left side (in the case of the processing system  1  shown in the upper part of  FIG. 4 ) or from the right side (in the case of the processing system  1  shown in the lower part of  FIG. 4 ) as seen from the common operating control unit  25 . 
         [0046]      FIG. 5  shows a schematic flow diagram illustrating the transfer method in accordance with an embodiment of the invention. 
         [0047]    According to the transfer method  50  illustrated in  FIG. 5 , there is provided a rotating  51  of a transfer rotor having a plurality of transfer elements (see  FIGS. 1 to 3 ). Upon rotating  51  the transfer rotor, there are to processes taking place for a respective transfer element, i.e. a changing  52  of a distance between the mounting point of the transfer element on the transfer rotor and the holding position together with a pivoting  53  the transfer element around the mounting axis. 
         [0048]    The changing  52  of the distance and the pivoting  53  are provided such that for a predetermined period or portion a path of the holding position of the transfer element coincides with a path of a holding position of a corresponding holding element of the processing machine (see  FIG. 1  and above discussion). During at least a part of such coinciding, there is provided a transferring  54  of the can from being held at the holding position of the transfer element to being held by the holding element of the processing machine (or vice versa). 
         [0049]    Typically partially temporally overlapping with this process  58  of changing  52 , pivoting  53  and transferring  54  a further corresponding process  59  occurs for the next transfer element, also including a changing  55 , a pivoting  56  and a transferring  57  in corresponding manner. 
         [0050]    During the rotation, the overlapping of processes  58  and  59  is provided repeatedly, wherein the number of partially parallel or overlapping processes depends of the details and the arrangement of the particular embodiment. 
         [0051]    In the case illustrated in  FIG. 1 , six transfer elements are simultaneously pivoted and have the distance of the holding position to the mounting axis changed, while four cans are shown during the coinciding of the paths. 
         [0052]    While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. 
         [0053]    The discussion above with respect to the figures illustrating embodiments referred to the case that the cylindrical containers are cans (i.e. containers with a closed bottom). The invention is not to be understood as being limited to processing cylindrical containers like can (i.e. containers with a closed bottom), but also applies to cylindrical containers or bodies without a closed bottom, indeed to bodies likes tubes or pipes as well. The container may also have a partially closed bottom. 
         [0054]    Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. 
         [0055]    In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or an does not exclude a plurality. 
         [0056]    A computer program may be stored and/or distributed on a suitable medium, such as an optical storage medium or a solid-state medium, supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. 
         [0057]    Any reference signs in the claims should not be construed as limiting the scope.