Abstract:
An apparatus for the sterile filling of containers sterilizes the containers before supplying them, with their caps on, to a substantially airtight chamber for filling. A precision lead screw precisely positions each container under the appropriate capping/uncapping mechanism and the appropriate filling needle. Filling and capping of each container is individually controlled so that each container is filled with a precise amount of liquid, and each cap is applied with the proper torque. The minimized number of components of the system minimizes the potential openings through which unfiltered air may enter the apparatus. Keeping the containers capped except while they&#39;re actually being filled minimizes the opportunity for any bacteria or viruses to enter the container.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of U.S. provisional patent application No. 60/606,818, filed Sep. 2, 2004, entitled “Apparatus and Method of Sterile Filling of Containers.” 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to the automated filling of containers. More specifically, the invention provides apparatus and method for the sterile filling of capped containers.  
         [0004]     2. Description of the Related Art  
         [0005]     Over numerous methods of filling container have been proposed, none provides the degree of sterility along with the flexibility and ease of changing from one size and shape of container to another as the present invention.  
         [0006]     An example of a container filling system is disclosed in U.S. Patent Application Ser. No. 2004/0088951 A1. This patent discloses a syringe handling, labeling, filling, and capping system. The system begins with multiple syringes connected to a belt. The belt is separable into individual portions with sufficient space for labeling the individual portions of the belt. The plunger and cap have previously been applied to the syringe in a clean room. The belt with syringes is sterilized by gamma rays. The spacing of the syringes on the belt corresponds to the spacing of hold locations on a holder for holding the syringes in place while operations are being performed. With the syringe being held in the holder, the cap is removed, the syringe filled, and the cap replaced. The cap retainer is moved along with the syringe during filling to keep the two together. The position of the plunger may be monitored with optical or pressure sensors. In an alternative embodiment, when the cap is removed, it is held at a cap removal and recapping location, while the syringes are moved to a filling location. After filling, the syringes will be returned to the uncapping/capping location so that the caps may be reapplied.  
         [0007]     U.S. Pat. No. 6,729,366 discloses a plurality of fill nozzles for containers having flow meters. Air pressure in a tank of fluid is adjusted based on the output of the flow meters to maintain constant fluid flow. A valve for each nozzle is shut off when the flow meter indicates that the proper fill level is reached.  
         [0008]     U.S. Pat. No. 6,530,402 discloses a container filling machine having a plurality of filling pipes, each of which has an electronic flow meter controlling a valve for shutting off fluid flow at the appropriate time.  
         [0009]     U.S. Pat. No. 5,129,212 discloses the automatic sterilizing and filling of containers. Sterilization is performed by gaseous hydrogen peroxide or irradiation. Once the containers, which in this case are flexible capped bags, are sterilized, the cap is removed. The bag is filled with the desired contents, and the bag spout is recapped. A cap detector assembly prevents filling of the container if the pressure of the cap is not detected in the cap holder.  
         [0010]     U.S. Patent Application Ser. No. 2003/0041560 discloses a rotary capping system for regulating the torque applied to screw-on type caps. The system uses an inflatable chuck controlled by a closed loop feedback control system wherein a computer controls a servomotor to apply torque until the desired torque is reached.  
         [0011]     U.S. Pat. No. 5,016,688 describes a system for emptying, cleaning, filling, and recapping roller bottles. The bottles are decapped, tilted to empty their contents, and then turned upright. A cleaning liquid is introduced, and the bottles are then tilted to empty the cleaning liquid from the bottles. The bottles are again turned upright, filled with an appropriate medium for cultures and CO 2 , and capped.  
         [0012]     U.S. Pat. No. 4,804,024 discloses an apparatus for filling containers. The apparatus includes a first work station for unscrewing the caps of the containers, a second work station for filling of the containers, and a third work station for reapplying the screw-on caps to the containers.  
         [0013]     U.S. Pat. No. 4,761,936 discloses a system for emptying, cleaning, and filling bottles with a culture medium. The bottle is first decapped, and the liquid is sucked therefrom. The bottle is next filled with a cleaning liquid and rolled horizontally with the cleaning liquid therein. The cleaning liquid is then sucked from the bottle. Culture medium is supplied to the bottle, and the bottle is recapped.  
         [0014]     U.S. Pat. No. 4,535,583 discloses a capping apparatus. Containers to be capped are mounted on a turntable. A capping head assembly includes a plurality of cap holders, with each cap holder corresponding to a container holder on the turntable. Torque is applied to each cap until it has reached a predetermined level.  
         [0015]     U.S. Pat. No. 4,401,141 discloses a container filling machine. The machine includes a flow meter generating signals indicative of the amount of fluid flow through a line leading to a nozzle for filling the container. The signals from the flow meter are counted, and the feed line is shut off when a predetermined number of counts is reached.  
         [0016]     U.S. Pat. No. 4,004,620 discloses a container filling system using a feed screw shaped to fit the containers to transport the containers into position under the filling nozzles. The number of rotations of feed screw are monitored to track the position of the container. A photoelectric gate mechanism detects the presence of containers to ensure that containers are present before filling begins. The nozzles are mounted on a walking beam arrangement so that the fill nozzles move with the containers as the containers are being filled.  
         [0017]     U.S. Pat. No. 3,870,175 discloses a method of decapping and emptying beer bottles. The method includes the use of a sensor to ensure that the cap is removed.  
         [0018]     None of the above references is seen as providing the advantages of a minimized member of components within each feed line, signified design, for the resulting decreased opportunity for bacteria or viruses to enter the system. Furthermore, the above references are not seen as providing the precise filling and capping control of the present invention. Accordingly, there is a need for an improved apparatus for the sterile filling of containers having simplified design, improved precision, and improved sterility.  
       SUMMARY OF THE INVENTION  
       [0019]     The present invention provides an improved apparatus and method for the sterile filling of containers.  
         [0020]     The containers, which will typically be bottles with screw caps, are provided to the machine with their caps on, thereby minimizing the opportunity for bacteria to enter the containers. The containers may have been sterilized, possibly by gamma radiation, prior to being supplied to the apparatus. The container loading station is preferably enclosed in an enclosure structured to resist the passage of unfiltered air therein.  
         [0021]     Each row of containers is taken from the bottle loading station and passed through a sterilization tube, wherein the containers are sterilized, for example, using ultraviolet radiation. Containers are released from the sterilization tube in batches equal to the number of containers to be filled by one filling cycle of the apparatus.  
         [0022]     On exiting the ultraviolet sterilization tube, the containers pass into a second substantially controlled environment, containing capping/uncapping and filling workstations therein. Containers are moved between a pair of feed screws, with the threads of the feed screws dimensioned and configured to hold a container therein, so the turning of the feed screws will control the movement and positioning of the containers. Upon reaching the capping/uncapping and filling stations, the movement of the containers will be secured between a brace fitting between the lead screw and the conveyor upon which the bottles rest, and a plate. The brace defines depressions therein that are structured to receive the bottles. The movement of the brace and plate are controlled by a lateral screw drive mechanism.  
         [0023]     The capping/uncapping workstation includes a plurality of rotating grippers, structured to grip the caps of the bottles. The jaws of the grippers secure the caps therein, and then the grippers rotate until the caps are removed from the bottles. After the grippers are raised, the lateral screw drive system moves the bottles from the capping station to the filling station, the filling workstation.  
         [0024]     The filling workstation includes a filling system corresponding to each of the containers. Each filling system includes a fluid feed line extending from a fluid source to a filling needle that is structured to be inserted into the top of the bottle. The fluid line passes through a flow meter that is operatively connected through a programmable logic controller to a valve. All containers are filled simultaneously, however, the programmable logic controller for each filling line will shut off the fluid flow into that container using the valve upon the proper amount of fluid flowing through the flow meter, so that the filling of each container is individually and precisely controlled.  
         [0025]     After filling, the containers are moved back to the capping station, where the caps have been maintained within the grippers. The grippers are lowered to place the caps on the containers, and then rotated until each of the caps has been applied to the correct torque. Individual torque measurement and control of each gripper insures that each cap is correctly and precisely applied with the correct torque.  
         [0026]     After the caps are reapplied, the containers are taken out of the enclosure and moved through a vision inspection system. Rejected containers are removed at a reject station.  
         [0027]     The system includes a clean-in-place system that will be used ensure a clean and sterile path for the fluid at the start of a filling process, or when the fluid or container size is changed. The system includes a drain having a plurality of apertures structured to receive the filling needles, along with the appropriate programmable logic controls. Upon actuation of the system, the needles will be lowered into the drain, a cleaner such as bleach will be passed through the filling needles, and steam will then be passed through the filling needles.  
         [0028]     The entire system minimizes the likelihood of bacteria entering the containers during the filling process. Because the containers are sterilized immediately before filling, they enter the enclosure with no bacteria in or on them. Because the caps are removed from the containers only immediately before filling, and replaced immediately after filling, with the filling done in a substantially controlled environment, opportunity for bacteria to enter the containers is again minimized. The use of filling lines with a minimum number of mechanical parts, for example, the diaphragm valve, again minimizes the opportunity for bacteria to enter the system. Minimized human intervention in the filling process further reduces the potential for contamination.  
         [0029]     Accordingly, it is an object of the present invention to provide apparatus for filing containers providing greater sterility than is provided by other presently available container filling systems.  
         [0030]     It is another object of the invention to provide a method of filling sterile containers that provides greater sterility than other methods.  
         [0031]     It is a further object of the invention to provide an apparatus and method for the sterile filling of containers that minimizes the length of time for which a cap is removed from the container.  
         [0032]     It is another object of the invention to provide a method of sterile filling containers that sterilizes the containers immediately before filling.  
         [0033]     It is a further object of the invention to provide a method of sterile filling of containers wherein each filling line includes a minimum number of mechanical components, thereby enhancing efficiency while also minimizing the opportunity for contamination of the contents of the containers.  
         [0034]     It is another object of the invention to provide an apparatus and method for sterile filling wherein volume of fluid dispensed to each container is individually controlled so that each container receives the correct amount of fluid despite any variation in flow rates.  
         [0035]     It is a further object of the invention to provide an apparatus and method for sterile filling of containers wherein the torque applied to each cap during capping is individually controlled to ensure that proper torque is applied to each cap.  
         [0036]     It is another object of the invention to provide a method of sterile filling containers having a vision inspection to avoid problems during the filling process and provide a means of inspection after filling.  
         [0037]     It is a further object of the invention to provide a clean and sterile path for the fluid with which the containers are being filled.  
         [0038]     These and other objects of the invention will become more apparent through the following description and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0039]      FIG. 1  is a top view of an apparatus for sterile filling of containers according to the present invention.  
         [0040]      FIG. 2  is a side view of an apparatus for sterile filling of containers according to the present invention.  
         [0041]      FIG. 3  is a top view of a container loading station for an apparatus for sterile filling of containers according to the present invention.  
         [0042]      FIG. 4  is a side view of a capping and uncapping station for an apparatus for sterile filling of containers according to the present invention.  
         [0043]      FIG. 5  is an end view of a capping and uncapping station for an apparatus and method for sterile filling of containers according to the present invention.  
         [0044]      FIG. 6  is a side view of a filling station for an apparatus for sterile filling of containers according to the present invention.  
         [0045]      FIG. 7  is an end view of a filling station for an apparatus for sterile filling of containers according to the present invention. 
     
    
       [0046]     Life reference characters denote like elements throughout the drawing.  
       DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0047]     The present invention provides an improved apparatus and method for the sterile filling of containers. Referring to  FIGS. 1-2 , the apparatus  10  includes a container loading station  12 , a sterilization tunnel  14 , a capping/uncapping station  16 , a filling station  18 , and an inspection system  20 .  
         [0048]     The container loading station  12 , best illustrated in  FIG. 3  supports a plurality of rows of containers  22  on a conveyor  24 . Containers  22  are loaded onto the conveyor  24  at its first end  26 , and are then transported into a loading station enclosure  28 , which is structured to resist the entrance of unfiltered air therein. The enclosure includes a filtered air intake  29 , which maintains a higher pressure of filtered air within the enclosure to resist the entrance of unfiltered air. The opposite end  30  of the conveyor  24  is in communication with the sterilization tunnel  14 , which is substantially parallel to the rows of containers  22  to facilitate the feeding of a row of containers  22  therein. An operator control panel  32  may be utilized with the container loading station  12 . The operator control panel  32  permits an operator to control the programmable logic controller, microprocessor, or computer that in turn controls the feeding of containers  22  into the sterilization tunnel  14 .  
         [0049]     The sterilization tunnel  14  includes a tunnel enclosure  34  having a conveyor  35  passing therethrough, and which is structured to permit the sterilization of containers passing therethrough, for example, by including ultraviolet light source therein (not shown and well known in the art). The electronics for the sterilization tunnel  14 , which are well known the art and therefore not shown, are housed in the enclosure  36 . Containers  22  are released from the sterilization tunnel  14  in batches equal to the number of containers to be filled during a filling cycle, which in the illustrated example is five containers.  
         [0050]     Referring to  FIGS. 1, 2 , and  6 , the opposite end of the sterilization tunnel  14  is in communication with a workstation enclosure  38 , having a filtered air intake  39 , which is structured to resist the entrance of unfiltered air therein, and to enclose the capping/uncapping station  16  and filling station  18 . After entering the enclosure  38 , the containers are separated by the lead screws  40 ,  42 , with the containers  22  fitting between these screws and being restrained by the threads on these screws. The longer lead screw  40  includes a first section  44  having narrow threads  46 , and a second section  48 , adjacent to the capping/uncapping station  16  and filling station  18 , having wider threads  50 . The second, shorter lead screw  42  includes narrow threads  52  corresponding to the threads  46  within the first section  44  of the lead screw  40 . As the conveyor  35  takes the containers between the lead screws  40 ,  42 , the containers will fit between the threads  46 ,  52 , so that the containers will be separated by the threads  46 ,  52 , and controlled by the movement of the lead screws  40 ,  42  instead of by the movement of the constantly moving conveyor  35 . Once the containers have reached the end of the lead screw  42 , their movement is controlled solely by the movement of the lead screw  40 . Therefore, once the lead screw  40  has moved the containers  22  into the capping/uncapping station  16  and filling station  18 , the containers are held in place by the lead screw, and are held at the proper spacing by the threads  50 . The lead screws  40 ,  42  may be changed to accommodate different size containers  22  by opening the levers  60 , removing the lead screws  40 ,  42 , substituting lead screws  40 ,  42  of a different size, and then closing the levers  60 . A brace is provided below the lead screw  40 , above the conveyor  35 , with the brace defining a plurality of depressions structured to receive the containers  22 . A plate  58  is disposed on the opposing side of the containers  22 , so that when the lead screw  40  has properly positioned the containers  22  and the brace is moved against the containers  22 , the containers are secured between the brace and the plate  58 . The lateral movement of the brace and the plate  58  between the capping/uncapping station  16  and filling station  18  is controlled by the lateral drive screw mechanism  56 .  
         [0051]     The capping/uncapping station  16  is best illustrated in  FIGS. 4-5 . The capping/uncapping station  16  includes a plurality of rotating grippers  62 , each having jaws  64  structured to grip a cap  66  of a container  22 . Each of the rotating grippers  62  is controlled by an individual servo motor  68 . The motor  68  is operatively connected to the gripper  62  by the drive shaft  70 , having a wider section  72  that passes through an opening within the housing  74 . The servo motor  68  requires an amount of electrical current that is directly proportional to the torque applied by the motor  68  to the cap  66 . Therefore, the amount of current drawn by the motor  68  provides a measure of the torque applied by the motor  68 , and the motor  68  may be stopped when the measured current reaches the amount corresponding to the desired torque. The motor  68  is mounted on the mount  76 , which is mounted to the rotary union  78 . The rotary union  78  is secured to a linear slide  80  that is slidably mounted on a support bracket  81 . Raising and lowering of the linear slide  80  is controlled by motor  82 , thereby permitting the entire motor driven cap removal assembly  84  to be raised upward to lift the cap  66  away from the container  22 , and to be lowered to bring the cap  66  into engagement with the container  22 . The rotary union  78  defines a pair of air intakes  79 , through which air may be directed into the assembly  84  by an air compressor system (not shown and well-known in the art) and against the jaws  64 , so that air pressure may push the jaws open or closed as needed, in a manner well-known in the art of mechanical jaws. The actuation of the air compressor system is controlled by an appropriate programmable logic controller, microprocessor, or computer. Referring to  FIGS. 2 and 7 , the housing  74  is mounted on a pair of adjustable legs  86 , thereby permitting the height of the housing  74  to be adjusted to accommodate containers  22  of varying heights.  
         [0052]     The filling station  18  is best illustrated in  FIGS. 2, 6 , and  7 . The filling station  18  includes a fluid supply line  88  in communication with a plurality of flow meters  90 , which are five in number in the illustrated embodiment. The exit end  92  of each flow meter  90  is secured to a flexible hose  94  passing through a pinch valve  96 . The amount of fluid passing through the flow meter  90  is provided as a signal to a microprocessor, programmable logic controller, or computer, which sends a signal to close the pinch valve  96  upon a predetermined amount of fluid passing through the flow meter  90 . The hose  94  terminates at the bracket  98 , wherein it connects with the filling needle  100 . The bracket  98  is mounted on a pair of extendible legs  102 , which may in some embodiments take the form of a hydraulic cylinder, thereby permitting the bracket  98 , and therefore the filling needle  100 , to be raised and lowered. In some embodiments, the filling needle  100  will be equipped with a second valve, thereby preventing any excess drip into the containers  22  after the pinch valve  96  is closed. Some embodiments may also include a photoelectric system to ensure that each cap has been removed from each bottle before the filling needles are lowered into the bottles. If the beam passing over the top of the container  22  is broken by the presence of the cap  66 , the photoelectric receiver will not receive the beam transmitted by the opposing photoelectric transmitter, so that the programmable logic controller or other controller that controls the filling process may be signaled to stop the filling process.  
         [0053]     The conveyor  35  terminates at the exit end of the enclosure  38 , adjacent to a transfer plate (not shown) and a second conveyor  104 . Air is drawn into the enclosure  38  through the filtered air intakes  39  at sufficient pressure to insure that, when the enclosure  38  is open to permit the container  22  to exit, air flows from inside the enclosure  38  to the outside, thereby resisting the entrance of unfiltered air into the enclosure. The containers  22  are then taken through a vision inspection system  106 , where the containers are checked for fill volume and cap placement. Any containers showing indications of problems are pushed to the reject station  108  by a solenoid-actuated punch.  
         [0054]     The apparatus  10  includes a clean-in-place system having a drain  110  which is located within the enclosure  38  underneath the filling needles  100 , and defines a plurality of holes  112  therein, with each hole  112  being structured to receive one of the filling needle  100 . The system may also include microprocessor-controlled cleaning, whereby a cleaning fluid and/or steam may be automatically passed through the filling needles  100  to the drain  110  by actuation of the appropriate controls of a control panel  32 .  
         [0055]     The entire process of filling containers may be controlled by a microprocessor, programmable logic controller, and/or computer. Containers that have been loaded into the enclosure  28  will be released onto the conveyor  35  from the container  28  one row at a time. The containers will be sterilized as they pass through the sterilization tunnel  14 , possibly using ultraviolet radiation. Upon exiting the sterilization tunnel  34 , they will enter the enclosure  38 , entering the space between the lead screws  40 ,  42 . The lead screws  40 ,  42  will separate the containers  22 , and will accurately position them for the capping/uncapping operation and the filling operation. The assembly  84  will be lowered by the motor  82 , with air pressure holding the jaws  64  open, until the jaws are on opposing sides of the cap  66 . Air pressure will then be released and the jaws  64  allowed to close under spring pressure around the cap  66 . The motor  68  will then rotate the cap  66  until it has been disengaged from the threads of the container  22 , and the motor assembly  84  and linear slide  80  will be raised upward by the motor  82 . The lateral screw drive mechanism  56  will then move the platform  54  so that the containers  22  are moved from the capping/uncapping station  16  to the filling station  18 . The legs  102  will be retracted so that the filling needles  100  are lowered into the container  22 , stopping at a position near the bottom of the container  22 . Fluid will then be injected into the container  22 , with the needles  100  being raised to maintain a position just above the surface of the liquid within the container  22 , until the proper quantity of fluid has passed through the flow meter  90 , at which point the pinch valve  96  will receive the appropriate signal from the programmable logic controller and cut off further fluid flow. The legs  102  will extend, raising the bracket  98 , raising the filling needle  100  out of the container  22 . The lateral screw drive mechanism  56  will then move the platform  54  in the opposite direction, thereby positioning the containers under the capping/uncapping station  16 . The linear slide motor  82  will lower the linear slide  80  and the assembly  84  to place the cap  66  back on the container  22 , and the motor  68  will then rotate the gripper  62  until the current required to operate the motor  68  is at a sufficient level to indicate that the proper torque has been reached. Air pressure will then be drawn into the mechanism to force the jaws  64  away from the cap  66 , and the assembly  84  will again be raised away from the container  22 . The container  22  will then exit the enclosure  38  and proceed to inspection.  
         [0056]     When it is desired to begin filling containers with a different liquid, the apparatus  10  may be cleaned using the clean in place system. With the needle  100  lowered into the hole  112 , a cleaner, for example, bleach, may be pumped through the system, followed by steam, which may in some preferred embodiments be at a pressure of about 25 p.s.i. and a temperature of about 125° C. The programmable logic controller may be programmed using techniques well known to those skilled in the art to perform the cleaning function in response to the push of a single button on the control panel.  
         [0057]     From the above description, it will be apparent that the apparatus and method of the present invention is capable of filling containers with unparalled sterility. The containers are initially stored within the enclosure  28 , which resists the entrance of unfiltered air by maintaining a positive air pressure of filtered air. The container  22  are taken directly from the loading station enclosure  28  to a sterilization tunnel  34 , where they are sterilized and then immediately moved to the enclosure  38  without contact with the outside air. The enclosure  38  again maintains a positive pressure of filtered air to resist the entrance of unfiltered outside air. Because the caps have remained on the bottles up until this point, any bacteria or viruses that may have entered the enclosure  38  have a minimized likelihood of entering the container  22 . Upon the removal of the cap  66  from the container  22 , the containers are moved to the filling station, filled, and moved back to the capping/uncapping station to have their caps replaced, so that some preferred embodiments leave the containers  22  uncapped for only about ten seconds or a similarly short time period. The fluid lines are designed with a minimum of mechanical parts, thereby minimizing the number of openings through which bacteria or viruses may enter. As the containers exit the enclosure  38 , a positive pressure of filtered air is maintained to resist the entrance of unfiltered air. The need for human contact with the apparatus and the resulting potential for contamination has been minimized.  
         [0058]     While a specific embodiment of the invention has been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.