Patent Publication Number: US-2007102262-A1

Title: Continuous motion article diverting system

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a system for moving conveyable articles to varying positions away from the initial position while the articles are being conveyed at high speeds. More particularly, the invention relates to a system for moving articles, such as containers, approximately perpendicular from a continuous path to varying positions away from the initial position while the articles are being moved at high speeds.  
      2. Related Art  
      Certain steps in the manufacturing of plastic containers require a means for transporting containers between processes, machines or locations. Examples of transport methods include: bulk conveying of randomly oriented containers by conveyor belt; bulk conveying of randomly oriented container by pneumatic/vacuum transport tubes; single file conveying of deliberately oriented containers by conveyor belt; and single file conveying of deliberately oriented containers by air-driven or rail guided conveyor. These methods are used in a broad range of industries at speeds varying from a few containers per minute to over 2,000 containers per minute. Thus, the increased line speeds requires more complex control systems that require more highly skilled technicians to service and maintain.  
      While the above transport methods and associated means for conveyance are suitable for many applications, they share a common weakness in that the containers conveyed in bulk or in single file are not easily divided into multiple streams with any level of accuracy or control. In the container industry, there is a need to divide a single row of containers into multiple parallel rows while the containers are being transported from one conveyance to a plurality of conveyances. Known means to accomplish this goal can be found in U.S. Pat. No. 5,441,142 to Schneider (diverter blade); U.S. Pat. No. 4,723,649 to Hartness et al. (pivoting guide chute); U.S. Pat. No. 6,772,872 to Spangenberg et al. (selectively movable guide channel); U.S. Pat. No. 6,715,600 to Ronchi (deviating arm); U.S. Pat. No. 5,944,165 to Mannlein et al. (rocker plate and rocker arms); U.S. Pat. No. 5,115,902 to Snyder et al. (lane divider system); U.S. Pat. No. 4,941,561 to Yamabe et al. (endless chain sorting device with slidable conveying boards); U.S. Pat. No. 4,830,173 to Hartness et al. (pivotally mounted chute); and U.S. Pat. No. 4,817,779 to Beck et al (pivoting guide track).  
      One of the know deficiencies of conventional gating/divider systems is the difficulty in repeatedly, accurately and reliably performing the dividing operation. Many of the devices discussed above fail to precisely control the position and orientation of the container during transfer from a single row to a row of multiple parallel rows. Proper container handling in any conveyance/divider system is dependent upon multiple variables including container weight, center of gravity, material of construction, line speed and control systems. Long term trends in the container industry have decreased container weights, which tends to raise the center of gravity, thereby resulting in containers that are more difficult to control during conveyance. In addition, the change of materials has made containers more difficult to handle than those that stand stable during conveying. Consequently, the prior art lacks positional control and precision for dividing containers thereby allowing containers to fall, tilt, jam or otherwise interrupt the flow of the dividing process.  
      Other prior art solutions require the containers in motion to be stopped while the pivoting guide chute, selectively movable guide channel, or other diverting blade transitions from one delivery point to another delivery point. Stopping containers in motion on a conveyor creates potential for disruptions and jams. In addition, large lengths of conveyance placed upstream and downstream of the gating/divider system are required so that there is sufficient space for the containers to accumulate while waiting for the gating/divider device to transition from one point to another point. Complex control routines that route the containers in a different direction are also used in combination with the large lengths of conveyance so that the containers are circulated while the gating/divider system is transitioning. Complex control routines and large lengths of conveyance require large capital outlays, as well as large areas of floor space to accommodate the need to stop containers while the gating/divider device is transitioning.  
     SUMMARY OF THE INVENTION  
      Applicants overcome shortcomings in the prior art with their inventive system, which allows articles to be separated into multiple positions while in continuous motion. In addition, the inventive system operates with a high level of precision and control over the position of the article at extremely high speeds.  
      For example, this can be achieved with an apparatus for positioning conveyed articles, such as containers at different lengths from an initial or loading position according to an embodiment of the invention. In a preferred embodiment, the apparatus would position containers in a direction parallel to the axis of travel. The inventive conveying and positioning apparatus includes an endless loop transport system that moves a number of articles in a direction of transport; guide rails attached to the transport system and extending approximately perpendicular to the direction of transport; a holding device movably disposed on a respective guide rail; and a controller for moving the holding device perpendicular to the direction of transport along the respective guide rail where articles are gripped by a holding device while in continuous motion at an initial position and moved to different lengths along the guide rails.  
      In one embodiment, the inventive continuous conveying and positioning apparatus may employ an endless loop transport system including at least two starwheels spaced from one another and a segmented conveyor moving around the at least two starwheels. The endless transport system of this embodiment may move the articles, such as containers in a substantially horizontal plane with respect to the segmented conveyor.  
      In another embodiment, the endless loop transport system includes first and second segmented conveyors spaced from one another and moving together in the direction of transport, at least two sets of rotary starwheels spaced from one another along a spindle with the first and second segmented conveyors surrounding the at least two rotary starwheels. The endless transport of this embodiment may have one set of starwheels and spindle positioned above the other set of starwheels and spindle so that the transport system moves in a substantially vertical manner, and wherein the gripped articles extend outwardly from the respective guide rail so that the sides and bottom of the article are exposed and can be visually checked manually or with an automated system (such as a camera).  
      The positioning and conveying apparatus according to the invention is relatively simple, compact and enables precise positioning of articles being conveyed by positively controlling the articles with the holding device. The positive control allows for higher speeds and more efficient operation. As a result, overall system lifetime purchase and operating costs will be much lower than conventional gating/divider systems. The positioning and conveying apparatus according to the invention can be directly linked to other machines or conveyors with no intermediate conveyors.  
      Precise, positive control of the articles is achieved with the positioning and conveying apparatus of the invention. One embodiment of the invention employs a holding device with one of a gripper, suction cup, spindle or chuck to hold the articles. A combination of rotary conveyors, mechanical gripping devices and a control system enables the positioning and conveying apparatus of the invention to be more dependable and robust than conventional gating/divider systems, which rely on forces such as gravity, air pressure and inertia for positioning, control and handling of articles.  
      As a result of the inventive positioning and conveying apparatus, more precise controls over positioning of articles is achieved with a simpler control system. In addition, the precise control allows for robust components that have the ability to operate at higher speeds and at lower costs than conventional systems.  
      The positioning and conveying apparatus according to the invention does not need lengthy conveyance runs, as the articles continue to move when being gripped by the holding device. Consequently, a smaller foot print and relative costs are obtained with the inventive system over conventional gating/divider systems.  
      In another embodiment according to the invention, a positioning and conveying apparatus for containers would be able to positively interface with an existing bottle blowing and testing equipment without releasing the container from the positive control of the holding device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.  
       FIG. 1  illustrates an apparatus for positioning and conveying containers according to one embodiment of the invention;  
       FIG. 2  shows a planar view of the system using the apparatus of  FIG. 1 ;  
       FIG. 3  illustrates the linking of the apparatus of  FIG. 1  with other container processing machines;  
       FIG. 4  illustrates an apparatus for positioning and conveying containers according to a second embodiment of the invention;  
       FIG. 5  shows another view of the apparatus of  FIG. 4 ;  
       FIG. 6  shows another embodiment of the positioning and conveying apparatus receiving a series of parallel streams of articles and positioning the articles into a single stream; and  
       FIGS. 7 and 8  show other view of the embodiment of  FIG. 6 .  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      As shown in  FIG. 1 , a line of articles, such as containers C are introduced to an infeed station so that the containers C are fed single file to the apparatus  1  for positioning conveyed containers at different lengths from an initial position. One exemplary embodiment of a infeed station, as shown in  FIG. 1  is a starwheel arrangement. Containers C are introduced to a first starwheel  10  and then moved to a second starwheel  12  of the apparatus  1 . Starwheels  10  and  12  rotate about a respective axis and have grooves  14  spaced from one another for receiving a container C. The spacing of the grooves enables containers C to move in single line at a predetermined speed.  
      An endless loop transport system circles a third starwheel  16  disposed, in this exemplary embodiment, on the same axis as the second starwheel  12  and a fourth starwheel  18 . It is envisioned that the third and second starwheel could be on different axes. The diameters of the third and fourth starwheels  16 ,  18  are smaller than the diameters of the first and second starwheels  10 ,  12 . The endless loop transport system  19  may be a segmented conveyor such as a chain conveyor where each segment  20  corresponds to grooves  17  of the third and fourth starwheels  16 ,  18 . The axes of starwheels  10 ,  12 ,  16  and  18  rotate at approximately the same speed so that containers C move into apparatus  1  in conjunction with the movement of endless loop transport system  19 . Thus, a line of containers C are supplied by the first starwheel  10  in single file and are transferred to second starwheel  12  where the containers C enter the apparatus  1  for positioning conveyed containers at different lengths from an initial position. In the embodiment shown in  FIG. 1 , containers C may move along a table-top or a substantially horizontal plane, as the containers travel with the apparatus  1 .  
      Each segment  20  of the endless loop transport system  19  has at least one guide rail  22  extending therefrom in a direction approximately perpendicular to the direction of transport T. The direction of transport T may be in the counter-clockwise or clockwise direction. A holding device  24  is movably disposed along the at least one guide rail  22 . Holding device  24  includes a gripper  26  for holding the container C. Gripper  26  may grip the sides of the neck of the container, or be a suction cup, spindle or chuck that positively holds the container.  
      Looking at  FIG. 2 , containers C are loaded onto holding device  24  while the containers are conveyed by second starwheel  12  after being transferred from first starwheel  10 . Initially, holding device  24  moves into alignment over the neck of a container C after the container C has rotated to the third groove position of starwheel  12 . Then, the gripper  26  of holding device  24  secures container C over the next segment  28  of starwheel  12  while the container is moving along the transport system  19 .  
      A guide rail  22  may include two rods  30 ,  32  separated by a distance. The holding device  24  moves along those rods bringing a gripped container C to a distance parallel to the direction of travel T. One end of the rods is segment  20  of the segmented conveyor and at the other end of the rods is a stop  34 . Stop  34  serves two purposes: 1) holds the rods  30 ,  32  of the guide rail  22  in place and 2) does not allow holding device  24  to move beyond this point and thus serves as a end of the guide rail  22 .  
      A controller  36 , such as a computer, causes a pneumatic or mechanical diverter to move holding device  24  perpendicular to the direction of transport T along the respective guide rail  22  so that a gripped container C can be positioned at different lengths from the segmented conveyor while moving in continuous motion with the endless loop transport system. As shown in  FIGS. 1 and 2 , containers C can be positioned at a first position next to the segmented conveyor to enter a first delivery lane, a second position B spaced from the segmented conveyor so that the containers C are lined up to enter a second delivery lane up to a fifth position E to line up with a fifth delivery lane. While 5 delivery lanes are shown in this exemplary embodiment, the guide rail  22  can have varying lengths depending upon the amount of delivery lanes desired or other processing lanes desired.  
      Holding device  24  grips a container C at segment  28  of starwheel  12  and then the controller  36  begins to orient containers C after they pass starwheel  12 . A positioning control enables (or causes) holding device  24  to move along guide rails  22  to an exact position so that the gripped container is moved to a desired transition point (e.g., aligned with a delivery lane). The positioning control may be a notch in the guide rail and a sensor in the holding device  24  that communicates to the controller which position the holding device  24  has reached as it moves outwardly from the segmented conveyor or other known positioning control means. The positioning control may move the holding device  24  along a respective guide rail  22  from the initial position to an exact position where the gripped container may be visually inspected, checked for leaks, etc and then moved to other positions for sorting. In an embodiment for visual inspection, etc., the segmented endless loop conveyor  19  may be arranged so that the gripped containers C are suspended from the conveyor above the ground so that the sides and bottoms of the container are accessible for visual inspection and other automatic checks on the container.  
      The holding device  24  remains in the desired position until the container C reaches a point where it is to be released. Generally, this is before the holding device  24  reaches starwheel  18 . In the exemplary embodiment shown in  FIGS. 1-3 , the holding device  24  remains in the desired position until the containers C are in the delivery lane and its segment  20  of the segmented conveyor reaches starwheel  18 . When the containers C are in the delivery lane, the containers C are removed from the gripper  26  of holding device  24 . As shown in  FIG. 2 , when segment  20  reaches starwheel  18 , gripper  26  releases container C and holding device  24  continues to move in the direction of transport T while container C is moved over the delivery lane in which it was positioned.  
      Alternatively, holding device  24  may release the containers C when they are positioned over a carton/packing case. In such an embodiment, the controller would move a line of containers C to a first position so that these containers line up with a carton and when released the container C are placed in the container and then a second line of containers C would be moved to a second position where the line up with the carton and are placed or released into the container, and so on. The carton may have a gate to allow a line of containers to be conveyed in, or the containers C may suspended above the carton and dropped in. If the containers C are suspended over a table, the cartons may be moved to a predetermined location under the line of containers and then the line of containers may be placed in the carton. If a cartons or packaging units with a gate are used, they may enter the path perpendicular to the line of conveying containers.  
       FIG. 3  illustrates the linking of an embodiment of apparatus  1  according to the invention with another container processing machine  40 . In this exemplary embodiment, two starwheels  42 ,  44  take containers C from processing machine  40  in single file and then rotate around a larger diameter transition starwheel  46  and two additional starwheels  48 ,  50  before reaching the starwheel  10  of apparatus  1 .  
      Another embodiment of the invention is illustrated in  FIGS. 4 and 5 . In this embodiment, the endless loop conveyor  19  includes a first segmented conveyor  52  and a second segmented conveyor  54  that are spaced from one another and move in the direction of transport T. At least two sets of rotary starwheels  56 ,  58  rotate about respective axes  56 A,  58 A. Each set of rotary starwheels  56 ,  58  has two starwheels spaced from one another along a spindle or respective axis ( 56 A,  58 A) where starwheels of one set  56  are in substantially the same plane as starwheels of the other set  58 . Segmented conveyor  52  rotates about the one plane of starwheels  56 ,  58  and segmented conveyor  54  rotates about the other plane of starwheels  56 ,  58 .  
      A guide rail  60  extends substantially perpendicular to the direction of transport T from a segment  52   s  of segmented conveyor  52  to a segment  54   s  of segmented conveyor  54 . A holding device  55  is movably attached to the guide rail  60  so that it can move to varying positions between the two segmented conveyors  52 ,  54 . The guide rail may include two rods  60   a ,  60   b  separated by a distance where the holding device  55  moves along these rods from an initial position near the first segmented conveyor to different positions moving toward the second segmented conveyor.  
      In the embodiment of  FIGS. 4 and 5 , the containers C are delivered in single file to an infeed station that can be, for example, a number of cradles  62  forming an endless loop conveyor  64 . The endless loop conveyor  64  surrounds two starwheels  66 ,  68  that rotate about respective axes  66 A,  68 A. The rotation of starwheels  66 ,  68  and the set of starwheels  56 ,  58  are controlled so that the containers C are moved at substantially the same speed on both conveyors  52 ,  64 . While axes  56 A,  58 A, as shown in  FIGS. 4 and 5 , are disposed perpendicular to the ground and axes  66 A,  68 A are substantially parallel to the ground, it is possible that in another embodiment the endless loop conveyor  64  and segmented conveyors  52 ,  54  may be disposed vertically with respect to the ground. In such an embodiment, containers C would be placed in a cradle  62  at starwheel  66  and then move along the conveyor  64 . Similar to the embodiment shown in  FIG. 2 , containers C entering starwheel  68  would be gripped by holding devices  55  and then moved upward parallel to the segmented conveyors  52 ,  54  of endless loop conveyor  19 .  
      In a vertical embodiment, axes  56 A,  58 A of the two sets of rotary starwheels  56 ,  58  about which the segmented conveyors rotate are substantially parallel with the ground and are perpendicular to axes  66 A,  68 A. The segmented conveyors endless loop  19  is positioned so that the containers C placed in cradles  62  move adjacent to holding devices  55  extending between the segmented conveyors  52 ,  54 . The containers C gripped by holding devices  55  are held substantially perpendicular to the respective guide rail. The holding device  55  may include one of a gripper, suction cup, spindle or chuck to positively hold a container C while moving along the endless loop conveyor and a respective guide rail  60 .  
      In the exemplary embodiment shown in  FIGS. 4-5 , the initial position of the holding device  55  corresponds with the neck of the container C placed in the cradle  62 . A positioning control moves the holding device  55  along a respective guide rail  60  from the initial position to an exact position where the gripped container may be visually inspected, checked for leaks, etc and then moved to other positions for sorting. In that the segmented endless loop conveyor  19  is arranged substantially vertical to the ground and that the holding device  55  grips the containers C so that they extend outwardly or approximately perpendicular to the guide rail  60 , the sides and bottoms of the container are accessible for visual inspection and other automatic checks on the container.  
      After visual inspection of a container is complete, the containers C can be moved to a final position for sorting. The vertical position of the segmented conveyors and guide rails allows machinery to check for leaks as well as visual inspection to occur while the containers C are moving along the endless loop conveyor  19 . Once the gripped container C reaches a desired transition point, holding device  55  may release the container so that container C can move away from the apparatus  1  for positioning conveyed containers at different lengths from an initial position while the holding device  55  continues to move in the direction of transport T.  
      In another embodiment of the apparatus for positioning conveyed articles, the system as described above would run backwards. That is, as shown in  FIGS. 6-8 , a series of parallel streams of articles (containers C) are fed into the apparatus, which is a continuous motion combining device. Each parallel stream of articles is routed to a timing screw  70 . In such a configuration, the majority of components and the configuration of the continuous motion diverting system would remain unchanged. However, a timing device, as described below, would be added and the conveyors would more in reverse.  
      The continuous motion combining device would receive a number of parallel streams of articles, such as multiple lanes (infeed lanes) of single file containers being conveyed and they would enter the device via a timing device that would separate the parallel streams of articles. For example, the conveyed streams of containers would terminate into star wheels, timing screws, or other appropriate device capable of creating a definite spacing of the articles. The timing devices would ensure that the articles to be combined arrive at a set spacing allowing for alternating feed from each of the infeed lanes. As shown in the  FIGS. 6-8 , the timing screws are designed so that each timing device feeds a container onto every fourth spindle of a holding device  55 .  
      In such an arrangement, articles could be loaded onto all of the spindles of the holding devices  55  moving between first segmented conveyor  52  and second segmented conveyor  54 . As the endless loop conveyor  19  is moved forward in the clockwise direction, the articles leave the control of the timing device (timing screws  70 ) and are gripped by the suction cup, spindle or chuck of holding device  55 . Each holding device is moved to an initial position to a location corresponding to the infeed lane of the next container C to enter the endless loop conveyor  19 . Then, as the endless loop conveyor  19  moves, the holding devices  55  are moved perpendicular to the direction of travel so that the gripped containers C are aligned in a single axis. The gripped containers C are received by a cradle  62  of a endless loop conveyor  64 . At this point, the gripper of the holding device  55  is released and the containers C are moved into a single file out feed conveyance (arrow  74 ).  
      The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. All examples presented are representative and non-limiting. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. While the invention is described with respect to containers and a horizontal (containers move along a table) and a vertical orientation of endless conveyor systems, different orientations may be possible and still achieve continuous diverting of containers while moving continuously along a transport system. Similarly, any type of conveyable article may be used. That is, machine parts, candy, boxes/cartons and cases or anything that can be picked up with a gripper, suction cup or chuck may be employed as the article being conveyed and positioned. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.