Patent Publication Number: US-2007119382-A1

Title: Bedding dispensing system and method

Description:
TECHNICAL FIELD  
      The present invention relates to a bedding dispensing system and method; more particularly, the present invention is directed to a bedding dispensing system and method that efficiently and accurately dispenses clean cage bedding into one or more cage components.  
     BACKGROUND OF THE INVENTION  
      A conventional cage system for holding small laboratory animals is typically a three piece assembly having a clear plastic bottom, a grill for holding food and water, and a lid that attaches to the bottom and holds the grill in place. A suitable bedding material, such as cedar shavings, may be added to the bottom portion of the cage assembly to absorb animal waste and spilled food.  
      While in use, the bedding becomes soiled, thereby necessitating the need for frequent cleaning of the cages. The cleaning process is typically a manual process that requires the cage components be manually disassembled, the soiled bedding be removed from the bottom portion of the cage, washed, and dried for reuse.  
      Instead of manually cleaning the cases, robotic arms are also known to assist laboratory personnel with the cage cleaning process. For example, after the cages are transported to a cage washing system, the robotic arms remove the soiled cage bottoms from a pallet, invert the cage bottoms to empty the soiled bedding material, and place the empty/soiled cage bottoms in an appropriate position on a conveyor. Since the pallet may also come into contact with the soiled material, the pallet is also placed on the conveyor by the robots so that they may be cleaned. The conveyor advances the cage bottoms and the pallets through a chamber or tunnel wash system, wherein the cage bottoms and pallets are cleaned by a suitable process, usually involving high pressure streaming water. Furthermore, a drying process is typically accomplished by subjecting the cleaned, yet wet cage bottoms and pallets, to high velocity heated air. The other cage components, such as the grill and lid, may be cleaned in a similar manner.  
      Upon completion of the cleaning process, an automated device, such as an additional robotic arm (i.e., clean side robot), places the cleaned pallet onto a stationary out-feed conveyor, clean bedding is added to the cages, and the cages are stacked on the clean pallet. Once a sufficient number of cages are stacked on the pallet, the out-feed conveyor is turned on and the pallet is moved to an end of the conveyor to be loaded onto a cart so that the cages may be returned to service.  
      Typically, clean bedding is dispensed into the clean cages using a rainfall type bedding dispenser. In operation, one or more clean cages simply pass underneath the rainfall dispenser while the rainfall dispenser sprinkles bedding over a general area wherein the cages catch some of the bedding falling from the dispenser. The method of filling the clean cages with bedding using a rainfall type dispenser presents a number of drawbacks and deficiencies. For example, the rainfall dispenser operates to sprinkle bedding over a general area, and does not directly dispense bedding into cages. Thus, there are certain areas in which there are no cages passing underneath the rainfall dispenser. In these unoccupied areas, the bedding being dispensed is wasted. In addition, the amount of bedding dispensed into each of the cages from the rainfall dispenser may be inconsistent. This may result in an inadequate amount of bedding being dispensed into a cage or a waste of bedding in the instance where the amount of bedding dispensed in a cage is more than the optimal amount. Moreover, the use of the rainfall type bedding dispenser causes a substantial amount of bedding particulates to be suspended in the air, thereby creating an undesirable work environment for the operator of the cage cleaning system.  
      Another method of dispensing clean bedding is by filling the cages using a bedding dispensing device. For example, after the cages have been cleaned, two cages may be positioned underneath separate bedding dispensing chutes so that an operator can independently dispense clean bedding into each of the cages. This particular manual fill or vacuum assisted dispensing process is problematic in that it results in an inconsistent amount of bedding being dispensed into each of the cases. Also, this process of dispensing clean bedding may be positioned in a location that is offset and not in line with the end of the cage cleaning system. As a result, the operator may have to move the clean cage from the cage cleaning system to a bedding dispensing location in order to complete the process. Thus, the efficiency of the cage cleaning process is reduced.  
      Accordingly, there exists a need for a bedding dispensing system and method that accurately and efficiently dispenses clean bedding into the cage components. In addition, there exists a need for a bedding dispensing system and method that reduces the amount of bedding particulates that are suspended in the air when the bedding is dispensed into the cage components. The present invention fills these needs as well as other needs.  
     SUMMARY OF THE INVENTION  
      In order to overcome the above stated problems, the present invention provides a bedding dispensing system that is positioned inline with the cage cleaning conveyor and allows a plurality of cage bottoms to be simultaneously filled with a metered amount of clean bedding material to reduce the amount of clean bedding that is wasted. Thus, different types and sizes of cage bottoms can be efficiently filled using the bedding dispensing system. Further, the use of separate filling chutes allows the clean bedding material to be directly dispensed into the cage bottom, thereby reducing the amount of bedding particulates that are suspended in the air during the dispensing process. Moreover, the main bedding dispensing unit includes a window or transparent material covering an access port on the side of the bedding storage hopper for identifying how much clean bedding is located within the bedding storage hopper.  
      In particular, the present invention includes a system for simultaneously dispensing clean bedding material into a plurality of cage components. The system may include an inline conveyor and a bedding dispensing unit. The inline conveyor has a receiving end and a dispatch end, wherein the inline conveyor transports the at least one cage component from the receiving end to a filling position located at the dispatch end. The bedding dispensing unit is positioned over the dispatch end of the inline conveyor, wherein the bedding dispensing unit operates to simultaneously dispense clean bedding into the plurality of cage components, and preferably three to four cage components.  
      The inline conveyor may include at least one cage positioning guide that positions the plurality of cage components underneath the bedding dispensing unit in the filling position. At least one cage presence sensor may be used to determine when the plurality of cage components are located in the filling position.  
      The bedding dispensing unit may include a bedding storage hopper having an internal chamber for storing the bedding material. The bedding storage hopper may also include a plurality of filling chutes positioned over the filling position to dispense the bedding material from the internal chamber into the plurality of cage components. Further, the bedding storage hopper includes bottom end having a tapered portion that funnels toward the plurality of filling chutes. A valve is coupled with the filling chutes to control the amount of bedding dispensed by the filling chutes. An operator interface may be used to selectively open and close the valve to control amount of bedding dispensed by the filling chutes. An agitator may also be positioned within the internal chamber of the bedding storage hopper to prevent the bedding material from clumping inside the internal chamber.  
      The present invention also provides a method for filling a plurality of cage components with bedding material. The method includes providing an inline conveyor having a receiving end and a dispatch end, positioning a bedding dispensing unit over the dispatch end of the inline conveyor, transporting each of a plurality of cage components from the receiving end to a respective filling position located at the dispatch end, and simultaneously dispensing clean bedding from the internal chamber of the bedding dispensing unit into the plurality of cage components.  
      The method may further provide at least one cage positioning guide to position the plurality of cage components underneath the bedding dispensing unit in the respective filling positions. In addition, the method may include sensing when the plurality of cage components are located in the respective filling positions. Further, the method allows for the amount of bedding material in the bedding dispensing unit to be seen through a window in the bedding dispensing unit. Also, the bedding material may be agitated when the bedding material is dispensed into the plurality of cage components. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become appreciated and be more readily understood by reference to the following detailed description of one embodiment of the invention in conjunction with the accompanying drawings, wherein:  
       FIG. 1  is a flow diagram of an automated cage washing system;  
       FIG. 2  is a perspective view of a soil side of the automated cage washing system;  
       FIG. 3  is a perspective view of a clean side of the automated cage washing system;  
       FIG. 4  is a side elevation view of a bedding dispensing system according to the present invention;  
       FIG. 5  is a top view of the bedding dispensing system shown in  FIG. 4 ; and  
       FIG. 6  is a front elevation view of the bedding dispensing system shown in  FIG. 4 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring to the drawings in detail, and specifically to  FIG. 1 , a system for cleaning animal cages is shown and is designated as reference numeral  10 . The system utilizes of a pair of loading/unloading robots, referred to hereinafter as a soil side robot  11 , and a clean side robot  12 . Additionally, the system also utilizes an optical arranger robot  19 . Using robots in the washing system  10  is beneficial in that they limit human exposure to the soiled cages, and reduce the repetitive steps associated with the loading and unloading the cage components.  
      With additional reference to  FIG. 2 , one or more soiled cage bottoms  16   a  arrive at the cleaning area on a component cart  13 , or any other suitable device for transporting a plurality of soiled bottoms. Cart  13  further comprises at least one soiled component rack or pallet  14   a  that operates to hold a plurality of soiled cage bottoms  16   a . Pallet  14   a  holding one or more soiled cage bottoms  16   a  is removed from cart  13  and attached to an in-feed conveyor  22 . Once pallet  14   a  is securely placed on in-feed conveyor  22 , the pallet  14   a  holding soiled cage bottoms  16   a  advances toward soil side robot  11 . Soil side robot  11  grasps one or more cage bottoms  16   a  from pallet  14   a , inverts cage bottoms  16   a  over a soiled bedding receptacle  28  ( FIG. 1 ), or any device suitable for receiving the soiled bedding from cage bottoms  16   a , and places cage bottoms  16   a  in an inverted fashion (open end facing down) on a tunnel washer conveyor  24  leading to a tunnel wash system  15 , such as, for example, a continuous driven belt tunnel washer. Furthermore, soil side robot  11  also grasps, inverts, and places pallets  14   a  on tunnel washer conveyor  24  so they may be cleaned by tunnel wash system  15 .  
      Once an appropriate number of soiled cage bottoms  16   a  and pallets  14   a  are received into tunnel washing system  15 , cage bottoms  16   a  and pallets  14   a  are washed and dried by tunnel wash system  15 . As best seen in  FIGS. 1 and 3 , upon completion of the wash/dry process in tunnel washing system  15 , clean cage bottoms  16   b  and pallets  14   b  advance on tunnel washer conveyor  24 , toward a rainfall type clean bedding dispenser  18 . Prior to reaching rainfall type clean bedding dispenser  18 , pallets  14   b  are removed from tunnel washer conveyor  24  by clean side robot  12  and placed either in a holding location or location that is suitable to receive clean cage bottoms  16   b , such as an out-feed conveyor  56 . Cleaned cage bottoms  16   b  drop from tunnel washer conveyor  24  to an inline conveyor  17 . Inline conveyor  17  further comprises a receiving end  26  and a dispatch end  27 . The drop from tunnel washer conveyor  24  to inline conveyor  17  causes clean cage bottoms  16   b  to invert (open end facing up) when clean cage bottoms  16   b  enter receiving end  26  of inline conveyor  17 . The reorientation of clean cage bottoms  16   b  enables cage bottoms  16   b  to receive clean bedding from the rainfall type bedding dispenser  18 .  
      The turbulent conditions of the tunnel washing process, as well as the reorientation of cage bottoms  16   b  onto inline conveyor  17 , cause cage bottoms  16   b  to become skewed or disoriented. System  10  further comprises an optical arranger robot system for detecting skewed or disoriented cage bottoms  16   b  on inline conveyor  17 , and placing cage bottoms  16   b  in an orderly arrangement upon a cage bottom re-grip station  20 . Additionally, the optical arranger robot system can detect and reorient various cage bottoms, such as wire baskets used to transport water bottles, or serve to dispense bedding into cage bottoms.  
      In operation, as cage bottoms  16   b  with clean bedding progress toward dispatch end  27  of inline conveyor  17 , they pass below an optical eye  25 . Optical eye  25  is mounted on an elevated stationary structure  23  above inline conveyor  17 . Optical eye  25  is aptly positioned to view a predetermined area of inline conveyor  17 . While  FIG. 3  shows optical eye  25  mounted on an elevated stationary structure  23 , optical eye  25  may be mounted upon any suitable structure, such as, for example, optical arranger robot  19 . Specifically, optical eye  25  transmits a video signal, presenting the position of the skewed cage bottoms to an encoding device (not shown). The encoding device serves to convert the video signals received from optical eye  25  into command signals suitable for guiding optical arranger robot  19 .  
      Optical arranger robot  19  may be mounted adjacent to dispatch end  27  of inline conveyor  17  and cage bottom re-grip station  20  as illustrated in  FIG. 3 , or in any suitable position. As skewed cage bottoms progress toward optical arranger robot  19 , optical arranger robot  19  receives a command signal from the encoding device (not shown), providing the position of the cage bottoms, and enabling the optical arranger robot  19  to grasp the cage bottoms and place them on cage bottom re-grip station  20 . From cage bottom re-grip station  20 , cage bottoms  16   b  are lifted by clean side robot  12 , and stacked on clean pallet  14   b  so that cage bottoms  16   b  may be returned to service. Alternatively, clean side robot  12  may transfer cage bottoms  16   b  from re-grip station  20  directly to out-feed conveyor  56 .  
      While the description set forth above describes the cleaning of cage bottoms  16   b , the system  10  may be used for cleaning various other cage bottoms, such as grills for holding food and water and cage lids.  
      The present invention includes an improved bedding dispensing system  30  that may be used in place of the rainfall bedding dispenser  18  shown in  FIG. 3 . As best seen in  FIGS. 4-6 , bedding dispensing system  30  may include a main bedding dispensing unit  32  used in conjunction with inline conveyor  17 .  
      With particular reference to  FIGS. 4 and 5 , inline conveyor  17  is positioned downstream of tunnel conveyor washer  24  and includes receiving end  26  and dispatch end  27 . As stated above, the drop from tunnel washer conveyor  24  to inline conveyor  17  causes clean cage bottoms  16   b  to invert (open end facing up) when clean cage bottoms  16   b  enter receiving end  26  of inline conveyor  17 . Instead of being positioned in an intermediate location along inline conveyor  17  like rainfalls type dispenser  18 , as shown in  FIG. 3 , main bedding dispensing unit  32  is positioned adjacent to dispatch end  27  of inline conveyor  17  and operates to accurately, efficiently and simultaneously dispense a metered amount of clean bedding into clean cage bottoms  16   b.    
      As best seen in  FIGS. 4 and 5 , inline conveyor  17  includes a frame  34  that is supported by a plurality of support members  36 . A plurality of rollers  38  may be rotatably mounted to frame  34  and used to transport the clean cage bottoms  16   b  from receiving end  26  to dispatch end  27 . Rollers  38  may be stainless steel and coated with a protective coating, such as Casta-lon soft protective coating, to help prevent cage bottoms  16   b  from chipping or cracking during operation. With additional reference to  FIG. 6 , inline conveyor  17  may include a pair of deflection shields  40  that extend upwardly from opposite sides of frame  34  that operate to retain cage bottoms  16   b  on inline conveyor  17 .  
      As best seen in  FIG. 5 , one or more cage positioning guides  42  are mounted on dispatch end  27  of frame  34  and are arranged to position clean cage bottoms  16   b  in a filling position to receive clean bedding that is dispensed from main bedding dispensing unit  32 . For example, each of cage positioning guides  40  may extend in a direction parallel with the longitudinal axis of inline conveyor  17  and spaced apart a distance (D) that is slightly larger than the width (W 1 ) of the cage bottoms  16   b . It will be understood that cage position guides  40  may be adjustably mounted to a track or other mechanism that allows each of them to be repositioned to accommodate for cages having different widths (W 1 , W 2 ).  
      One or more cage presence sensors may be used to determine the presence or absence of a cage bottom  16   b  in the filling position. For example, the cage presence sensors may be located underneath where a cage bottom would be located in the filling location to prevent the main bedding dispensing unit  32  from dispensing bedding in cage bottom  16   b  after bedding was already dispensed in that particular cage bottom. Cage presence sensors can also be used to prevent bedding from being dispensed by main bedding dispensing unit  32  when a cage bottom  16   b  is not located in the filling position.  
      As best seen in  FIGS. 4 and 6 , inline conveyor  17  may also include an overflow tray  44  that is slidably mounted to inline conveyor  17  and positioned underneath dispatch end  27  to catch any clean bedding that is not caught by cage bottoms  16   b  after being washed in tunnel washer conveyor  24 . Overflow tray  44  may be slid out from underneath dispatch end  27  to empty any bedding material located therein. Inline conveyor  17  may also include a sloped water collection pan to accommodate and drain any excess water that drips off cage bottoms  16   b . A drain connection and drain plug may be provided to assist in cleaning and draining of the excess water.  
      As best seen in  FIGS. 4 and 6 , main bedding dispensing unit  32  includes a bedding storage hopper  46  that is positioned above dispatch end  27  of inline conveyor  17 . Bedding storage hopper  46  is supported by a hopper support frame  48  and is used as a storage compartment for clean bedding material. Specifically, clean bedding material may either be manually dumped into bedding storage hopper  46  through an access port  50  formed in a side wall  53  of bedding storage hopper  46 , or automatically transported into the bedding storage hopper  46  using a pneumatic vacuum system. The access port  50  may be covered with a removable window  51  that prevents clean bedding material from spilling out of bedding storage hopper  46 , and allows for visual verification of clean bedding levels within bedding storage hopper  46 .  
      The vacuum system may include a vacuum that is connected to a vacuum port  52  that opens up into the internal chamber of bedding storage hopper  46 . The vacuum system may also include a tube or other transportation means that is connected between a bedding supply source and a conveyance port  54  that also opens up into the internal chamber of bedding storage hopper  46 . As the vacuum operates to draw air out of the internal chamber of bedding storage hopper  46 , the clean bedding is drawn into the internal chamber of bedding storage hopper  46 , thereby filling up bedding storage hopper  46 . The level or amount of clean bedding material located in bedding storage hopper  46  may be determined using adjustable high/low capacitive sensors  58 .  
      Bedding storage hopper  46  also may include a tapered section  60  at a bottom end  62  thereof that operates to funnel the clean bedding material to preferably three or four filling chutes  64 . An agitator  65  may be located within bedding storage hopper  46  to agitate the clean bedding within bedding storage hopper  46  each time bedding is dispensed through filling chutes  64  and into a cage bottom. The agitation of the bedding material prevents the bedding material located in bedding storage hopper  46  from clumping and reduces bridging concerns associated with certain types of bedding materials.  
      As best seen in  FIGS. 4 and 6 , each of the filling chutes  64  may be positioned above the filling position where a respective cage bottom  16   b  may be aligned by cage positioning guides  42 . Using separate filling chutes  64  for each cage bottom  16   b  increases the directional accuracy and concentration of bedding flow that is being dispensed, thereby reducing the amount of dust particulates that are suspended in the air during the filling of the cages. Since each of the filling chutes  64  are used to fill a single cage bottom, a substantial portion of the bedding that is dispensed through the filling chute  64  is captured by cage bottom, thereby reducing the amount of bedding that is wasted using the rainfall type bedding dispenser.  
      The amount of clean bedding material that is dispensed through each of the filling chutes  64  is controlled by one or more valves  66 . Each of the valves  66  are coupled with a respective filling chute  64 , wherein the valves  66  may be a pneumatic slide gate shutter valve or any other device that operates to meter the amount of clean bedding that flows through filling chutes  64  and into the cage bottoms  16   b . Specifically, each of the valves  66  may be opened and then closed to dispense a specific amount of bedding material into a cage bottom  16   b  by touching a control button  68 , which is in turn connected to an operator control interface  70 .  
      Operator control interface  70  may operate to display the status of system  30 , allow the operator to control the type of cage to be filled, allow the dispensing volumes to be adjusted by controlling the amount of time that valves  66  are in an open position, control the operation of agitator  65 , and provide a start and stop time for each filling cycle. Operator control interface  70  may also be configured to communicate with a main control center or server through a network to accept communications from an external source, communicate with other bedding dispensing systems, and allow for software control, upgrades, maintenance, and fault isolation. In addition to allowing an operator to visually determine the amount of bedding material located within bedding storage hopper  46  through window  51 , control interface  70  may be connected to capacitive sensors  58  to allow the operator to monitor the level of bedding material located within the bedding storage hopper  46 .  
      In operation, clean bedding materials may be placed into bedding storage hopper  46  either manually or automatically. If the bedding is placed in the bedding storage hopper  46  manually, the window  51  that covers access port  50  may be removed so that the bedding may be inserted into the internal chamber through access port  50 . If the bedding is placed in the bedding storage hopper  46  automatically using the vacuum system, a vacuum is turned on, thereby drawing air out of the internal chamber of bedding storage hopper  46  through vacuum port  52 . The vacuum pressure in turn draws clean bedding from the bedding supply source into the internal chamber of bedding storage hopper  46  through conveyance port  54 . The automatic bedding filling can be controlled by control interface  70 , which may be used to selectively turn the vacuum on and off. It will be understood that bedding storage hopper  46  may be filled before, during or after the cage bottoms  16   b  are filled with clean bedding to provide for an efficient cage washing and filling system.  
      The cage positioning guides  42  may be manually adjusted, or automatically adjusted by operator interface  70 , to the distance (D) that is slightly greater than the width (W 1 , W 2 ) of the cage bottom that will be filled to properly align each of the cage bottoms beneath a respective filling chute  64 .  
      Upon completion of the wash/dry process in tunnel washing system  15 , clean cage bottoms  16   b  may advance on tunnel washer conveyor  24 , toward bedding dispensing system  30 . As best seen in  FIG. 4 , cleaned cage bottoms  16   b  drop from tunnel washer conveyor  24  to inline conveyor  17 . The drop from tunnel washer conveyor  24  to inline conveyor  17  causes clean cage bottoms  16   b  to invert (open end facing up) when clean cage bottoms  16   b  enter receiving end  26  of inline conveyor  17 .  
      The turbulent conditions of the tunnel washing process, as well as the reorientation of cage bottoms  16   b  onto inline conveyor  17 , cause cage bottoms  16   b  to become skewed or disoriented. Cage bottoms  16   b  are prevented from falling off of inline conveyor  17  by deflection shields  40  positioned on opposite sides of inline conveyor  17 . As cage bottoms  16   b  approach dispatch end  27  of inline conveyor  17 , cage bottoms  16   b  are placed in the filling position between a pair of cage positioning guides  42  to properly position cage bottoms underneath a respective filling chute  64 . It will be understood that cage bottoms  16   b  may be manually placed between cage positioning guides  42  by an operator, or automatically placed using optical arranger robot  19  ( FIG. 3 ). The cage presence sensors then operate to sense the presence of a cage bottom  16   b  in the filling position.  
      The operator interface  70  is then instructed to simultaneously dispense a metered amount of clean bedding material into cage bottoms  16   b  using control button  68 . After control button  68  is activated, a signal is sent to operator interface  70  indicating that the valves  66  should be opened to simultaneously dispense clean bedding material into cage bottoms  16   b . It will be understood that operator interface  70  will only instruct clean bedding to be dispensed through those valves  66  and associated filling chutes  64  that have a cage bottom  16   b  located in a respective filling position, which is determined by the cage presence sensors. The amount of time that each valve is in the open position to dispense bedding at least in part depends on the amount of bedding that is to be dispensed into each cage bottom and the flow rate of the bedding that is dispensed from filling chute  64 . It will be understood that each of the valves  66  and associated filling chutes  64  can operate to dispense the same amount or different amounts of bedding material relative to one another. Therefore, various sizes and types of cage bottoms are simultaneously filled using bedding dispensing system  30 , even if they need to be filled with different amounts of clean bedding. As clean bedding is being dispensed into one or more cage bottoms  16   b  from bedding storage hopper  46 , agitator  65  may be turned on by operator interface  70  to reduce the chance that the clean bedding will clump in the tapered portion  60  of bedding storage hopper  46 .  
      After valves  66  have closed and clean bedding is no longer being dispensed into cage bottoms  16   b , the cage presence sensors continue to sense that the same cage bottom  16   b  is located in the fill position and prevents the main bedding from dispensing bedding for a second time in the same cage bottom. Cage bottoms  16   b  may then be manually lifted, or automatically lifted by clean side robot  12 , and stacked on clean pallet  14   b  so that cage bottoms  16   b  may be returned to service. Alternatively, clean side robot  12  may transfer cage bottoms  16   b  from dispatch end  27  directly to out-feed conveyor  56  as seen in  FIG. 3 . Once the cage bottoms are removed from dispatch end  27  of inline conveyor  17 , cage presence sensors are used to prevent bedding from being dispensed by main bedding dispensing unit  32  until another cage bottom is placed in the filling position.  
      The bedding dispensing system described above provides a number of advantages over existing rainfall type bedding dispensers. For example, the present invention includes a main bedding dispensing unit positioned at a dispatch end of the inline conveyor having separate filling chutes for each cage bottom. The use of three or four separate filling chutes allows multiple cage bottoms to be simultaneously filled with a specific amount of clean bedding material to efficiently fill the cage bottoms and reduce the amount of clean bedding that is wasted. Thus, different types and sizes of cage bottoms can be filled using the bedding dispensing system. Further, the use of separate filling chutes allows the clean bedding material to be directly dispensed into the cage bottom, thereby reducing the amount of bedding particulates that are suspended in the air during the dispensing process. Moreover, the main bedding dispensing unit includes a window covering an access port on the side of the bedding storage hopper for identifying how much clean bedding is located within the bedding storage hopper.  
      Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.  
      All features disclosed in the specification, including the claims, abstract, and drawings, and all the steps in any method or process disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. Each feature disclosed in the specification, including the claims, abstract, and drawings, can be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.