Abstract:
A method for processing containers in a container-processing machine includes identifying a first container behind an adjacent second container in a container flow, the first container being positioned within the container flow such that the first container will, absent intervention, occupy a first processing position that has been designated as not to be occupied by any container, holding the first container back, thereby causing the first container to move with a second velocity, that is less than the first velocity, forming a gap between the first and second containers, and releasing the first container. As a result of having been held back, will now occupy a second processing position instead of the first processing position.

Description:
RELATED APPLICATIONS 
     This application is the national stage, under 35 USC 371, of international application PCT/EP2014/001113, filed on Apr. 25, 2014, which claims the benefit of the May 28, 2013 priority date of German application DE 102013105460.9, the contents of which are herein incorporated by reference. 
     FIELD OF INVENTION 
     The invention concerns container processing, and in particular, to container-processing machinery having defective processing elements. 
     BACKGROUND 
     A container processing machine typically includes a rotating conveyor element that has many processing stations for processing containers. The conveyor element is very often a rotor that can be driven to rotate about a vertical machine axis. 
     A variety of processing stations are possible depending on what sort of container processing is contemplated. Examples include: filling elements used in a filling machine for filling containers; sealing elements for use in a sealing machine or closing machine for sealing filled containers with a suitable container closure; inspection elements for use in an inspection machine for inspecting empty containers before filling and/or for inspecting filled containers; labeling elements used in a labeling machine for labeling containers, printing stations used in printing machine for the application of decoration in the form of printed images onto containers; and cleaning heads used in a cleaning machine for cleaning and/or sterilizing containers. With so many processing positions, it is almost inevitable that a few of them will eventually become defective. Containers at these defective positions will not be processed correctly. For example, containers processed at a defective filling station may not be filled to the correct level. Containers processed at a defective cleaning station may not be properly sterilized. 
     In many cases, it is not economical to shut down production to fix a small number of defective processing stations. After all, doing so will result in considerable lost production. It is more economical to simply discard those containers that have had the misfortune of having been processed by a faulty processing station. 
     SUMMARY 
     Although it is economically rational to simply discard containers that are known to have been processed by a faulty processing station, it is still the case that the discarded containers have a cost. 
     Among the objects of the invention is that of reliably preventing containers from being transferred into defective processing positions in the first place and doing so without a machine stoppage. This prevents containers from being incorrectly processed at defective processing positions, and thus avoids waste associated with discarding improperly processed containers. 
     The invention assumes that for each processing position on the circulating conveyor of the container-processing machine, there exists an unambiguous association with corresponding positions of the container flow on the conveying path of the container feed at any moment in normal problem-free operation. In the event that a processing position is not to be used and is thus also not to be occupied, for example in the event that a processing position is defective, it is possible to create, in the flow of containers on the conveying path of the container feed, a gap in the container flow and to do so in such a way that this gap, and not a container, is transferred to the processing position that is not to be occupied. The same applies similarly for two or more consecutive processing positions in the conveying direction of the conveyor element. 
     In one aspect, the invention features a method for processing containers in a container-processing machine that has a plurality of processing positions formed on a circulating conveyor. Such a method includes causing the containers to form a container flow that flows with a first velocity along a container path in a conveying direction, obtaining information indicative of an association between a position of a container in the container flow and a defined processing position on the conveyor, designating a first processing position from the plurality of processing positions as not to be occupied by any container, identifying a first container behind a second container in the container flow, the first container being positioned within the container flow such that the first container will, absent intervention, occupy the first processing position, holding the first container back, thereby causing the first container to move with a second velocity, that is less than the first velocity, forming a gap between the first and second containers, releasing the first container, and causing the first container to occupy a second processing position instead of the first processing position. 
     In some practices of the invention, designating a first processing position from the plurality of processing positions as not to be occupied by any container includes receiving information indicative of a fault in the first processing station. 
     In other practices of the invention, holding the first container back includes causing a retaining element to transition from a first state to a second state, wherein, when the retaining element is in the first state, the retaining element is outside the container path, and wherein, when the retaining element is in the second state, the retaining element acts as a barrier to forward movement of the first container. Among these are those practices that further including, after having formed the gap, and with the retaining element in the second state, moving the retaining element at the first velocity, while moving the retaining element, supporting the first container, and, upon reaching a feed that spaces the containers from each other prior to transferring the containers to processing positions, causing the retaining element to transition to the first state. Also among these practices are that that further include, after having formed the gap, causing the retaining element to move in a direction opposite the conveying direction to a starting position thereof. 
     In yet other practices, holding the first container back includes, from a starting position of the retaining element, accelerating the retaining element along the conveying direction, while the retaining element is moving at the first velocity, causing the retaining element to transition from the first state to the second state, and, with the retaining element in the second state, decelerating the retaining element to the second velocity thereby causing the first container to decelerate to the first velocity. Among these are practices that also include, after having formed the gap, accelerating the retaining element to the first velocity, and causing the first container to resume motion at the first velocity. 
     Certain alternative practices of the invention also include using a supporting element to support the second container while forming a gap between the first and second containers, and withdrawing the supporting element when the second container reaches a feed that spaces the containers from each other prior to transferring the containers to processing positions. Among these are those in which using the supporting element includes accelerating the supporting element from a starting position thereof, in which the supporting element is outside the conveying path, and, upon reaching a supporting position between the first and second containers, causing the supporting element to move at the first velocity so as to cause the supporting element to move synchronously with the containers in the container flow. 
     In another aspect, the invention features a container-processing machine for processing containers. Such a container-processing machine includes a circulating conveyor, processing positions disposed around the conveyor, a container feed that defines a container path in which a container flow includes containers moving at a first velocity in a conveying direction are brought towards the processing positions, and a retaining element that holds back the first container thereby causing a gap to form between adjacent first and second containers in the container flow. The processing positions comprise a first processing position that has been designated as not to be occupied by any container and a second processing position that is available for being occupied by a container. The container flow is such that a position of a container in the container flow is indicative of a particular processing position that is to be occupied by the container. In the absence of intervention by the retaining element, the first container would occupy the forbidden first processing position. However, as a result of the gap, the first container will instead occupy the second processing position and not the first one. 
     In some embodiments, the retaining element is configured to be moved from a starting position outside the container path and into a retaining position in which the retaining element holds back the first container. Among these embodiments are those that include a process computer. In some embodiments, the process computer causes the retaining element to move synchronously with the container flow while supporting the first container until the first container reaches a feed that spaces the containers from each other prior to transferring the containers to processing positions at which point the retaining element ceases to support the first container. In other embodiments, the process computer causes the retaining element to be accelerated in the conveying direction from a starting position, the acceleration continuing until the retaining element attains the first velocity, to cause the retaining element to transition into a retaining position, to decelerate to a second velocity, to decelerate the first container, and to thereby form a gap between the first and second containers. In some of these embodiments, the process computer also, after having caused the retaining element to form the gap, accelerates the retaining element to the first velocity, thus causing further growth of the gap to cease. 
     In some embodiments, a process computer causes the retaining element to return to a starting position thereof after the retaining element has been used to form the gap. 
     Alternative embodiments feature a supporting element that is configured to move at the first velocity and to support the second container. 
     Yet other embodiments include a carriage that supports the retaining element. The carriage is configured to execute a forward stroke and a backward stroke. The stroke moves the carriage in the conveying direction from a starting position thereof. The backward stroke moves the carriage against the conveying direction and towards the starting position. The retaining element on the carriage transitions between a first, in which the retaining element remains outside the container path, and a second state, in the retaining element extends into the container path to affect the container flow. 
     In another aspect, the invention features a method for processing containers in a container-processing machine. Such a method includes identifying a first container behind an adjacent second container in a container flow, the first container being positioned within the container flow such that the first container will, absent intervention, occupy a first processing position that has been designated as not to be occupied by any container, holding the first container back, thereby causing the first container to move with a second velocity, that is less than the first velocity, forming a gap between the first and second containers, and releasing the first container. As a result of having been held back, will now occupy a second processing position instead of the first processing position. 
     As used herein, expressions such as “substantially” or “approximately” refer to deviations from an exact value in each case by ±10%, and preferably by ±5% and/or deviations in the form of changes not significant for function. 
     As used herein, “containers” include cans, bottles, tubes, pouches, whether made of metal, glass and/or plastic, as well as other packages, in particular those that are suitable for filling with liquid or viscous products, or those suitable for filling with powder or granulate. 
     In the case of containers moving with a velocity defined by a velocity vector along a conveying direction, a first point is said to be “downstream” of a second point when the second point can be reached by moving from the first point along the velocity vector. Conversely, a first point is said to be “upstream” of a second point when the second point can be reached by moving from the first point along the negative of the velocity vector. 
     Further developments, benefits, and application possibilities of the invention arise also from the following description of examples of embodiments and from the figures. Moreover, all characteristics described and/or illustrated individually or in any combination are categorically the subject of the invention, regardless of their inclusion in the claims or reference to them. The content of the claims is also an integral part of the description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features of the invention will be apparent from the following detailed description and the accompanying figures, in which: 
         FIG. 1  is a plan view of a container-processing machine; 
         FIGS. 2 and 3  show a retaining element of the container-processing machine  FIG. 1  in two operating states; and 
         FIGS. 4 and 5  show an embodiment similar to that shown in  FIGS. 2 and 3  but with dual retaining elements. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a container-processing machine  1  of a circulating design having a rotor  2  that can be driven about a vertical machine axis in a rotating direction A. Processing positions  3  are provided on a circumference of the rotor  2 . The processing positions  3  are offset from each other at regular angular distances about the vertical machine axis. Each processing position  3  accepts one container  4  to be processed. The container  4  is oriented with its container axis in a vertical direction so that it is parallel or substantially parallel to the machine axis. 
     A container feed  5  individually feeds containers to be processed  4  to the processing positions  3 . The container feed  5  spaces the containers apart along an axis in a manner consistent with the spacing between successive processing positions  3  on the circumference of the rotor  2 . 
     The container feed  5  includes a conveying path  6  formed by a conveyor. In the illustrated embodiment, the conveying path  6  extends in a straight line. A single track of containers  4  is fed in an incoming conveying direction B along this conveying path  6 . This results in a container flow moving with a conveyor velocity. In fault-free operation of the container-processing machine  1 , when all the processing positions  3  are working correctly the containers  4  are directly adjacent to each other with essentially no gap between them. 
     The container feed  5  also comprises a dividing worm  7  and a first conveyor star  8 . The dividing worm  7  acts as a spacing transformer to convert the spacing between containers  4  on the conveying path  6  so that it conforms to the spacing between successive processing positions  3  on the circumference of the rotor  2 . The first conveyor star  8  receives the spaced containers  4  from the dividing worm  7  and loads them into processing positions  3 . 
     At a container outlet  10 , a second conveyor star  9  receives processed containers  4  from the processing positions  3  and places them on an external conveyor  11 , which then takes them away along an outgoing conveying direction C towards a further use and/or for further processing. The dividing worm  7  and the first and second conveyor stars  8 ,  9  are all driven synchronously with the rotor  2 . 
     The processing positions  3  actually carry out their container processing only as the rotor  2  carries them through a processing sector defined by the rotor&#39;s rotary movement. The processing sector extends between the container feed  5  and the container outlet  10 . 
     In the illustrated embodiment, the container-processing machine is a labeling machine in which the rotor  2  carries the processing positions  3  past labeling units  12 . The container-processing machine can however also be designed for another kind of processing of the containers at the processing positions  3 . For example, in a container-printing machine for printing on the containers  3 , the labeling units  12  would be replaced by print heads. 
     A process computer  13  controls a retaining installation  14  shown in  FIGS. 2 and 3  as being installed at the container feed  5  just upstream of the dividing worm  7 . The retaining installation  14  causes gaps in the flow of containers into the processing positions  3  and does so in a targeted and controlled manner such that no containers are moved to a defective processing position  3 . 
     A first sensor  15  provides the computer  13  with information that correlates particular processing stations  3  with positions of containers  4  in the incoming container flow. As a result, the computer  13  is able to determine which processing station  3  will be receiving the next container from the incoming container flow. In addition, the computer  13  is provided with a list of faulty processing positions  3 . As a result, the computer  13  is in a position to instruct the retaining installation  14  to prevent a faulty processing position  3  from receiving a container  4 . 
     Upon recognizing that, without its intervention, a container  4  will be loaded into a faulty processing position  3 , the computer  13  issues an instruction to the retaining installation  14  to hold back a particular container until a suitable processing station  3  is available to receive it. 
     The retaining installation  14  comprises a finger-like retaining element  16  on a carriage  17 . The retaining element  16  extends horizontally or substantially horizontally along a retaining direction D that is perpendicular to the incoming conveying direction B. A first actuator  18  causes the retaining element  16  to transition between an inactive state, shown in  FIG. 2 , and an active state, shown in  FIG. 3 . 
     To transition the retaining element  16  into the inactive state, the first actuator  18  moves the retaining element  16  along the retaining direction D away the conveying path  6  until it is completely withdrawn and no longer interferes with container flow, as shown in  FIG. 2 . 
     To transition the retaining element  16  into the active state, the first actuator  18  moves the retaining element  16 , along the retaining direction D toward the conveying path  6 . As a result, the retaining element  16  extends into the movement path of the containers  4  approaching the conveyor worm  6 , thus blocking the containers&#39; progress, as shown in  FIG. 3 . This creates a gap  4 ′ in the container flow just upstream of the dividing worm  7  so that no container is moved into the faulty processing position  3 . 
     The retaining installation  14  also has a second actuator  19  that moves the carriage  17 , together with the retaining element  16  wither along the conveying direction B or against the conveying direction B′ between a start position, shown in  FIG. 2 , and an end position, shown in  FIG. 3 . In the start position, the carriage  17  and thus the retaining element  16  too is at a greater distance from the dividing worm  7  than it is in the end position. 
     In some cases, the computer  13  recognizes that there are no faulty processing positions  3 . Therefore, every processing position  3  is to be occupied by a container  4 . In that case, the computer  13  causes the carriage  17  and the retaining element  16  to remain in their starting position so that the single-track and compactly arranged container flow remains uninterrupted. 
     In other cases, the computer  13  recognizes that a particular processing position  3  is faulty and should not be occupied. In response, the computer  13  identifies, on the conveying path  6 , a particular container  4  that would normally be fed to this processing position  3 . Then, under instructions from the computer  13 , the second actuator  19  accelerates the carriage  17  until the retaining element  16  is just ahead of the particular container  4 . Having caught up with the particular container  4 , the second actuator  19  adjusts the carriage&#39;s velocity to match that of the particular container  4  so that the retaining element  16  now moves synchronously with the flow of containers on the conveying path  6 . 
     The first actuator  18  transitions the retaining element  16  into its active state so that it now acts as a barrier in front of the particular container  4 . With the retaining element  16  now in place, the second actuator  19  decelerates the carriage  17 . This causes a gap  4 ′ to form in the container flow downstream of the particular container  4 . 
     After having created a suitable gap  4 ′, the first actuator  18  transitions the retaining element  16  into the inactive state. The second actuator  19  then moves the carriage  17  against the incoming conveying direction and back to its starting position. This releases the particular container  4  so that it again proceeds towards the first conveyor star  8  at the conveyor velocity. However, as a result of having been delayed, the particular container  4  will arrive too late to be loaded into the faulty processing position  3  and will instead be loaded into a functioning processing position  3 . 
     In a preferred embodiment, the first actuator  18  does not withdraw the retaining element  16  immediately after the gap  4 ′ has been formed. Instead, with the retaining element  16  still in the active state, the second actuator  19  accelerates the carriage  17  to again match the conveying velocity of the conveying path  6 . The carriage  17  brings the retaining element  16  directly to the dividing worm  7  so that the retaining element  16  continues to support the particular container  4  until it has been loaded onto the dividing worm  7 . At the feed of the dividing worm  7 , the first actuator  18  withdraws the retaining element  16  into its inactive state and the second actuator  19  begins to move the carriage  17  back to its starting position. 
     To assist in controlling the retaining installation  14 , it is useful to provide second and third sensors  20 ,  21  to detect containers  4  on the conveying path  6 , to monitoring formation of the gap  4 ′, and to transmit such information back to the computer  13 , which then relies upon it to control the retaining installation  14 . 
     An alternative embodiment, shown in  FIGS. 4 and 5 , features a pair of identical first and second retaining installations  14 ,  14   a  disposed in opposite sides of the conveying path  6 . Up to the point shown in  FIG. 4 , the first and second retaining installations  14 ,  14   a  both work in a manner identical to that described in connection with the embodiment of  FIGS. 2 and 3 . As shown in  FIG. 4 , both retaining elements  16 ,  16   a  are directly between first and second containers and ready to form a gap  4 ′ between the first and second containers. 
     To form a gap, the second actuator  19  of the first retaining installation  14  decelerates the carriage  17  in the manner already described in connection with  FIGS. 2 and 3 . However, the second actuator  19  of the second retaining installation  14   a  does not decelerate its carriage  17 . As a result, as the gap  4 ′ forms, the first retaining element  16  remains directly in front of, or downstream from, the first container but the second retaining element  16   a  remains directly behind, or upstream of, the second container. This prevents the second container from toppling over backwards. 
     In an alternative embodiment, the first and second retaining installations  14  and  14   a  are arranged on the same side of the conveying path  6  but one on top of the other so that they do not interfere with each other&#39;s operation.