Abstract:
A device for introducing containers into a treatment space and for removing the containers from said treatment space having at least one rotatable sluice wheel provided on the periphery with sluice chambers that are open toward the outside, the sluice wheel being provided with grippers that can be operated directly by the containers or indirectly by a control device, for securing the containers temporarily in the sluice chambers, preferably by suspending the containers without allowing them to come in contact with the chamber walls and without providing any bottom support. A trouble-free conveyance of the containers with a very high output is possible without damaging the containers, even when the containers are very susceptible to tilting.

Description:
FIELD OF THE INVENTION 
     The present invention concerns a device for introducing containers into, and removing them from, a treatment space, such as in a beverage bottling operation. 
     BACKGROUND OF THE INVENTION 
     Such devices are known in various embodiments, where the containers are inserted into the sluice wheel or removed from it by rotating star wheels in combination with stationary guide rails (U.S. Pat. No. 5,457,939), by swivel arms with stationary swivel axes (U.S. Pat. No. 2,660,513) or by controlled radial slides mounted in the sluice wheel in combination with stationary guide rails (U.S. Pat. No. 1,766,018). With the known devices, the containers stand with their bottom surfaces on corresponding supporting surfaces of the chambers during conveyance in the sluice wheel, and are otherwise freely movable in the chambers. Therefore, their positions can easily change under the influence of the force of gravity plus optionally the supply and removal of gas acting on the chambers. This leads to problems in removing the containers, from the chambers, can cause damage to the containers and is possible only if the containers are sufficiently stable. Furthermore, a high efficiency in conveyance is impossible. 
     SUMMARY OF THE INVENTION 
     The object of this invention is to significantly improve the conveyance efficiency and operating reliability of a generic device with simple means even in handling containers with a low stability, and to reliably suppress damage to the containers. 
     With a device according to this invention, a reliable centering and stabilization of the containers in the sluice wheel is made possible through the grips arranged in the sluice chambers. Tilting of the containers, damage due to striking the chamber walls, or faulty transfer to downstream conveyance devices are reliably prevented and a very efficiency conveyance is made possible. 
     Various designs are possible for the grips in the sluice chambers. An especially simple design with reliable fixation of the containers is made possible by the invention. Other embodiments of this invention permit reliable conveyance at a high speed even when handling especially lightweight and unstable containers such as PET bottles. It is especially expedient if the conveyor elements that work together with the sluice wheel are provided with clamps for stable holding of the containers, so that even at the highest processing rates, it is reliably possible to introduce the containers into the sluice wheel and/or remove them from it. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One embodiment of this invention is described below on the basis of the figures, which show: 
     FIG. 1 a top view of a device for introducing bottles into a treatment space and removing them from the treatment space, partially in the form of sectional diagrams; 
     FIG. 2 section A-B according to FIG. 1; 
     FIG. 3 an enlarged top view of a single clamp of a star wheel; and 
     FIG. 4 an enlarged top view of a gripper of the sluice wheel. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The device according to FIGS. 1 through 4, labeled as  30  on the whole, is designed for introducing containers in the form of PET bottles, hereinafter referred to simply as bottles  1 , into a treatment space  2  which is under a high vacuum, and then removing the containers from said treatment space, where said bottles  1  are coated to increase the barrier properties. The treatment space  2  is hermetically sealed from the environment by walls  31  and it has a continuously revolving conveyor  23  with mandrels  32  that can be inserted into the opening in the bottles  1  and advances the bottles  1  to the coating facilities (not shown). 
     The device  30  has a horizontal base plate  33  on whose top side are mounted a central sluice wheel  4  and a total of four star wheels  17 ,  18 ,  19 ,  20 , each with a perpendicular axis of rotation that work together with the sluice wheel  4 . The sluice wheel  4  and the star wheels  17  through  20  are driven continuously in the direction of the arrow by drive elements (not shown) arranged beneath the base plate  33  in synchronization with one another and in synchronization with conveyor  23 , so that they mesh with one another essentially in the manner of gearwheels. 
     The sluice wheel  4  is equipped on the periphery with sluice chambers  3  that are open only radially toward the outside but are otherwise closed airtight; the height, depth and width of these sluice chambers is slightly greater than the largest bottle  1  to be processed. The surfaces of the sluice wheel  4  facing radially outward and bordering the sluice chambers  3  lie in a cylindrical surface arranged concentric with its axis of rotation and work together with suitably cylindrically curved sluice walls  34   a  and  34   b , which develop into walls  31   a  and  31   b  of treatment space  2  in an airtight manner. A rotating sluice is formed by the sluice wheel  4  and the sluice walls  34   a ,  34   b  which are rigidly connected to the base plate  33  at the bottom and to a cover plate  51  at the top, with the sluice chambers being open toward the treatment space  2  in the area adjacent to said treatment space, and being open toward the environment on the opposite peripheral area, while also being separated from the treatment space  2  as well as the environment in the two peripheral areas in between. The sealing function can be improved by means of gaskets (not shown) between the sluice wheel  4  and the sluice walls  34   a ,  34   b . In addition, the sluice chambers  3  can be connected to lines for supplying and/or removing gas in the area of the sluice walls  34   a ,  34   b.    
     Each sluice chamber  3  has its own gripper  6  with which the bottles  1  are centered and secured during their conveyance with the sluice wheel  4 , namely by suspension without any bottom support and without coming in contact with the walls of the sluice chambers  3 . Each gripper  6  has two essentially parallel swiveling levers  8 ,  9  arranged in the manner of gripper tongs in the horizontal plane of rotation of the sluice wheel  4  and essentially radially to its axis of rotation. The two swiveling levers  8 ,  9  are mounted pivotally on a common supporting plate  12  by means of bearing pins  35 ,  36 . The supporting plate  12  is in turn mounted detachably by means of a screw in a horizontal radial alignment in a recess  37  in the respective sluice chamber  3 , providing an airtight seal. 
     As shown in particular in FIG. 4, the swivel axes defined by bearing pins  35 ,  36  lie approximately in the middle of swiveling levers  8 ,  9 , dividing them into a gripper arm facing outward and a counter arm facing inward. Between the gripper arms, an elastic means  11  in the form of a rubber cushion is inserted, forcing the gripper arms apart and thus causing the grippers  6  to tend to open. On the free ends of the gripper arms, recesses  38 ,  39  shaped approximately in a quarter circle are formed, adapted to the diameter of the bottles  1  in the area to be gripped. In the present embodiment, that would be the neck of the bottle  1  directly beneath a neck collar  7  or carrying ring provided on the head of the bottle. With gripper  6  closed, the two recesses  38 ,  39  extend more than 180 degrees around the bottle neck and are in contact with it with a certain force, so that the respective bottle  1  is held in a form fitting manner and also by frictional engagement. Thus, an absolutely reliable method of securing even bottles  1  that are at great risk of tilting in the sluice chambers  3  is achieved even at high conveyance speeds and high acceleration, without supporting the bottles in the bottom area. 
     The opening and closing of the grippers  6  at the desired locations on the path of revolution of the sluice wheel  4  are accomplished by a control device labeled as  5  on the whole; its design is described below. A control cam  10  is mounted rotatably between the counter arms of each pair of swiveling levers  8 ,  9 . If this is standing essentially radially to the axis of rotation of the sluice wheel  4  (open position), the counter arms can approach one another to the maximum extent under the influence of the elastic means  11  and gripper  6  is opened. However, if the control cam  10  is essentially tangential to the axis of rotation of the sluice wheel  4  (closed position), as illustrated in FIG. 4, it causes the counter arms to be spread apart to the maximum extent, so the gripper arms with the recesses  38 ,  39  can be brought to the maximum proximity and gripper  6  is thus closed. Each control cam  10  is mounted on the lower end of a cam shaft  40  which is mounted rotatably in the sluice wheel  4  and parallel to the axis of rotation of the sluice wheel and projects slightly upward. A control lever  41  is mounted on the projecting end, so that the control cam  10  can be moved between its open position and its closed position, both of which are stabilized in a self-limiting manner. 
     The control levers  41  work together with four stationary bolt-like stops  13  through  16 , which are mounted in the cover plate  51  covering the sluice wheel  4  on the top and projecting into the path of revolution of the control levers  41 . The control levers  41  and the stops  13  through  16  are in the normal atmosphere, just like the annular space of the sluice wheel  4  between its spokes within the sluice chambers  3 . The cam shafts  40  are therefore sealed airtight and therefore do not permit any gas exchange between the sluice chambers  3  and the environment. 
     The four star wheels  17  through  20  have the same basic design which is described below on the basis of the first star wheel  17 . A horizontal star plate  43  is mounted on a vertical drive shaft  42  and has eight angle levers  44  distributed uniformly around the circumference and mounted so they can pivot about axes  45  arranged parallel to the drive shaft  42 . A first cam roller  46  is mounted on the inside leg of each angle lever  44  and engages in a first grooved cam  47  which is arranged in a stationary mount below the star plate  43  and controls the swiveling motion of the angle levers  44  during a rotation of the star plate  43 . 
     A sliding part  48  is mounted so that it is longitudinally displaceable on the outer leg of each angle lever  44  running approximately radially to the drive shaft  42 . This sliding part has a second cam roller  49  which engages in a second grooved cam  50 , which is arranged in a stationary mount above the star plate  43  and controls the radial movement of the sliding part  48 . A clamp  24  is arranged on the end of each sliding part  48  which points radially outward and projects out of the angle lever  44 . This clamp has swing arms  25 ,  26  arranged in the manner of scissors in the horizontal plane of rotation of the star wheel. These swing arms  25 ,  26  are mounted pivotally on the sliding part  48  by means of bearing pins  52 ,  53  and are put under tension in the closing direction by an elastic means  27  in the form of a tension spring. The legs of the swing arms  25 ,  26  pointing radially outward are bent in the shape of a quarter circle and are adapted to the diameter of the area of the bottles  1  to be gripped, encompassing more than 180 degrees. In this embodiment, this is the necked area between the top of the neck collar  7  and the lower edge of the thread on the head of the bottle. A bottle  1  can be gripped and secured reliably at this point without allowing the bottle to slip in the axial direction. Bottles  1  are also conveyed without any bottom support in the area of the star wheels  17  through  20 , so that no fitting parts are necessary for different bottle heights, and damage to the bottle surface is prevented. 
     Although the grippers  6  are indirectly operated by their control device  5 , the clamps  24  are operated directly by the bottles  1 . To do so, the free ends of the swing arms  25 ,  26  are provided with chamfered control faces  28 ,  29  which press the swing arms  25 ,  26  apart, against the force of the elastic means  27 , when a bottle  1  is pushed into the area between the swivel arms  25 ,  26  until the bottle  1  has snapped into place completely between the swing arms  25 ,  26 . Conversely, the swing arms  25 ,  26  are opened again due to their shape in the form of a quarter circle when a bottle  1  is pulled out against the force of elastic means  27 , until the bottle  1  has been snapped out completely. 
     As shown in FIG. 1, the first star wheel  17  is in the normal atmosphere outside the treatment space  2 . It takes the bottles  1  from a feed conveyor  21  in the form of an air conveyor in whose end area the bottles  1  are held at a distance and cycled into the system by two parallel feed screws  54   a ,  54   b  driven in synchronization with the star wheel  17 . By means of combined swiveling and radial movements of the sliding parts  48  controlled by the two grooved cams  47  and  50 , the clamps  24  are snapped onto the bottles  1 . Then the bottles  1  in the first star wheel  17  are slightly accelerated and brought to a greater distance by a mainly swiveling motion of sliding parts  48 , and finally they are inserted in a controlled manner into the orifices of the sluice chambers  3  and inserted precisely into the opened grippers  6 . On reaching the end position, the grippers  6  are closed by the stop  13  in the manner described above, after which the clamps  24  are pulled away from the bottles  1  by a predominantly radial movement and extracted from the sluice chambers  3 . Since the grippers  6  are below the neck collar and the clamps  24  below the neck collar and the clamps  24  above the neck collar  7  act on the bottles  1 , a problem-free transfer between these elements is thus possible. 
     The fourth star wheel  20 , like the adjacent first star wheel  17 , is in the normal atmosphere outside the treatment space  2 . It takes the bottles  1  from sluice wheel  4  and transfers them to a discharge conveyor  22  in the form of an air conveyor. By appropriate control of the sliding parts  48  by means of grooved cams  47  and  50 , the clamps  24  are snapped onto the bottles  1  which are still being held by the grippers  6  in the sluice chambers  3 , whereupon the grippers  6  are opened by the stop  16  in the manner described above. Then the bottles  1  in the star wheel  20  are delayed and their distance is reduced until they are inserted into discharge conveyor  22  with a relatively small distance. 
     The second star wheel  18  and the third star wheel  19  are adjacent within the treatment space  2 . The second star wheel  18  takes the bottles  1  from the grippers  6  of the sluice wheel  4  and transfers them at a reduced distance and reduced speed to the mandrels  32  of the conveyor  23 . In doing so, the grippers  6  are opened by the stop  14 . The third star wheel  19  takes the bottles  1  from the mandrels  32  of the conveyor  23  and transfers them at a greater distance and greater speed to the grippers  6  of the sluice wheel  4 . The grippers  6  are closed here by the stop  15 . The desired change of the distance and speed of the bottles  1  is also accomplished in the area of the star wheels  18  and  19 , and likewise the adaptation between the different pitch and speed of the sluice wheel  4  on the one hand and the conveyor  23  on the other hand is accomplished through an appropriate design of the two grooved cams  47  and  50 , just as is the predominant radial movement for snapping the bottles  1  in or out.