Patent Publication Number: US-6209705-B1

Title: Container transport system

Description:
This application is a divisional of U.S. patent application Ser. No. 08/744,538, filed on Nov. 6, 1996, now U.S. Pat. No. 5,881,429. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates in general to a container cleaning apparatus and more particularly to a cleaning apparatus that can be installed alongside a conveyor belt system. The apparatus is particularly well suited for cleaning empty containers of different sizes and shapes, and it can be installed at a selected location alongside an existing conveyor system or material-handling device designed to transport such containers. The container cleaning apparatus can be put in use with few if not any modifications to the existing conveyor belt. 
     BACKGROUND OF THE INVENTION 
     In the container industry, particularly where drugs or other edible materials are stored in bottle-like containers, it is necessary to subject the container to a cleaning process to remove any particulate contaminants such as dust that may be electrostatically attracted to the inner walls of the container. 
     To remove those contaminants, it is common practice to subject the containers to a cleaning operation. Typically, the containers transported on a conveyor belt are directed to a cleaning station that injects in the interior of the container an ionized high-velocity air stream to neutralize the electrostatic field that may exist on the walls of the container and place the contaminants attracted to it in suspension. Next a powerful negative pressure zone is created near the container mouth to suck away the suspended contaminants. 
     Existing container cleaning stations are fixed devices designed to be an integral part of the container processing line. Sometimes, a production run may not need to have containers cleaned, rendering the cleaning station not necessary. In those cases the presence of the cleaning station may be detrimental to operation of the processing line, as it may reduce the processing speed of the containers. Such a drawback, however, is unavoidable as the cleaning station can not be readily removed from the conveyor system. 
     Thus, there is a need in the industry to provide a cleaning station that is portable and can easily be incorporated into a conveyor system on which containers are transported. 
     OBJECTIVES AND STATEMENT OF THE INVENTION 
     It is a general object of the present invention to provide an improved cleaning apparatus for removing particulate contaminants from the interior of a container. 
     It is a further object of the invention to provide a container cleaning apparatus that is portable and may be readily installed alongside an existing conveyor system. 
     It is another object of the invention to provide a cleaning apparatus that can adjust to accommodate containers of different sizes without having to change pieces. 
     It is another object of the invention to provide a cleaning apparatus with an improved internal container transport system. 
     It is a further object of the invention to provide a cleaning apparatus that inverts the containers upside down (the mouth of the container facing down) to perform the cleaning operation. 
     As embodied and broadly described herein, the invention provides a portable container cleaning apparatus, that can be installed alongside a conveyor belt said apparatus comprising: 
     a container pick-up station capable of cooperating with a conveyor belt on which containers to be cleaned are transported to remove containers from the conveyor belt, said container pick-up station including a guide panel that can be extended across the conveyor belt and a rotating support surface to cause a container removed from the conveyor belt to travel along a sector of a circle; 
     a container transport system including an entry zone in the vicinity of said rotating support surface, said container transport system being capable of taking-up a container transported by said rotating surface along said sector of a circle and carrying the container along a predetermined path of travel, said container transport system also including an exit zone where a container is released; 
     a first station located for introducing in the container a high velocity gas stream for placing contaminants present in the container in suspension; 
     a second station located downstream from said first station with relation to a direction of movement of the container along said path of travel, said second station being capable of establishing a negative pressure zone to cause contaminants placed in suspension in the container to be removed by suction; and 
     a container return station located in the vicinity of said exit zone, said container return station including a guide panel that can be extended across the conveyor belt and a rotating surface capable of subjecting a container delivered from said exit zone to a movement along a path of travel along a sector of a circle, said container return station being capable of cooperating with the conveyor belt to return the container to the conveyor belt. 
     In a preferred embodiment, the container pick-up station includes a guide panel positioned to extend across the conveyor belt to direct oncoming containers onto a rotating table of the cleaning apparatus. The rotating table reverses the movement of the container so it is caused to travel in a direction opposite to that on the conveyor belt. An internal transport system grasps the container and transports it along a semi-circular path to invert it so its mouth faces down. A spray jet is located beneath the container and ejects a continuous powerful air stream that enters the mouth of the container to place in suspension any contaminants adhered to the inner walls of the container. A vacuum port immediately beneath the container sucks the suspended particulate material out from within the container. The internal transport system then directs the container to a return station that contains a rotating table orienting the container so it moves along the same direction as that of the conveyor. A guide panel assists in the transfer of the container from the cleaning apparatus to the conveyor belt. 
     In a most preferred embodiment, the internal transport system comprises two adjustable resilient belts that run alongside one another, one container width apart. The distance between the belts can be adjusted to accommodate containers of different sizes. The belts possess some degree of resiliency to insure a tight fit, and have a high coefficient of friction to prevent slippage between the belts&#39; surfaces and the containers. Besides transporting the containers, the belts are designed to impart rotary movement to the rotating tables. The belts are driven by an electrical motor or any other suitable power source. 
     Advantageously, the gas injected into the container is ionized so that it will neutralize electrostatic charges on the inner surface of the container to prevent particles from electrostatically clinging to the container&#39;s walls. 
     As embodied and broadly described herein the invention further provides a container cleaning apparatus, said apparatus comprising: 
     a container pick-up station capable of cooperating with a conveyor belt on which containers to be cleaned are transported in a mouth-facing-up condition, to remove a container from the conveyor belt, 
     a container transport system including an entry zone in a vicinity of said container pick-up station, said container transport system being capable of taking-up at said entry zone a container transported by said container pick-up station and carrying the container along a predetermined path of travel, said container transport system also including an exit zone where a container is released, said predetermined path of travel including: 
     a first run for orienting the container such that the mouth of the container faces down; 
     a second run downstream of said first run for transporting the container with the mouth of the container facing down; 
     a third run downstream of said second run for orienting the container such that the mouth of the container faces up; 
     a first station located along said path of travel for introducing in the container a high velocity gas stream for placing contaminants present in the container in suspension; 
     a second station located along said path of travel for establishing a negative pressure zone to cause contaminants placed in suspension in the container to be removed by suction; and 
     a container return station located the vicinity of said exit zone, said container return station being capable of cooperating with the conveyor belt to return the container to the conveyor belt in a mouth-facing-up condition. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the container cleaning apparatus in accordance to the invention placed alongside a conveyor belt; 
     FIG. 2 is a top elevational view of the cleaning apparatus; 
     FIG. 3 is a cross sectional view taken along the lines  3 — 3  in FIG. 2; 
     FIG. 4 is a partial cross-sectional view taken along the lines  4 — 4  in FIG. 2; and 
     FIG. 5 is a perspective view of a variant of the container cleaning apparatus. 
    
    
     DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring now to the drawings, FIG. 1 illustrates an improved container cleaning apparatus  10  that can be installed alongside a conveyor belt  6 . The cleaning apparatus comprises three main components, namely: a container pick-up station  20  designed to remove a container  2  from the conveyor belt  6  and convey it to an internal transport system  40  that moves the container through a container processing station that incorporates an air jet system  50  for generating a high velocity air stream, a vacuum port  70  to establish a negative pressure zone and finally, a container return station  80  that directs the cleaned containers back to the conveyor belt  6 . 
     As best shown in FIG. 2, the container pick-up station  20  comprises a guide panel  22  that directs oncoming containers  2  onto a rotating table  30  that feeds them to the container transport system  40 . The guide panel  22  that extends across the conveyor belt  6  is preferably placed at an angle of 45 degrees with respect to the longitudinal axis of the conveyor belt and comprises a curved portion fixed to the frame  90  of the apparatus  10 . The guide panel is fabricated of a material that generates minimal friction upon contact with the containers without scratching them, preferably a plastic composite. 
     The rotating table  30  of the container pick-up station as best seen in FIGS. 2 and 3, comprises a circular base  32  and hub  34 . The circular base  32  has a radius that is much larger than the diameter of a container  2 . A rotating shaft  38  is keyed to the circular base and to the hub  34 . The lower and intermediate portions of the shaft are fixed to respective bearings (not shown) secured to the frame  90  of the cleaning apparatus  10 . The upper portion of the shaft is mounted to a pulley  62 , extending above the circular base  32 , with a U-shaped cavity that receives belt  65 . The belt  65  drives the pulley  62  that rotates the shaft  38  which in turn causes the rotating table  30  to turn. Both the rotating table  30  and pulley  62  are preferably fabricated of aluminum while the shaft  38  is preferably made of stainless steel. 
     To provide a smooth uninterrupted surface over which containers can be moved between the conveyor belt  6  and the container cleaning apparatus  10 , a bottom plate  26  fills the gaps between the conveyor  6  and rotating table  30 . Moreover, a side panel  28  also extends from the inner edge of the conveyor belt toward the center of the rotating table  30 . The side panel in conjunction with the guide panel  22  form a channel that directs the containers from the conveyor belt toward the table  30 . The side panel is fabricated of material that generates little friction, preferably a plastic composite. 
     As best seen in FIG. 2, the transport system  40  comprises two belts  45  and  65 , support pulleys  44   a ,  44   b ,  44   c ,  44   d ,  44   e ,  44   f , shafts  47  (supporting pulleys  44   d , 44   e , 44   f ) and  49  (supporting pulleys  44   a , 44   b , 44   c ), an adjustment screw  60  and transmission  42 . The support pulleys  44  are preferably fabricated of aluminum and shafts  47  and  49  are preferably stainless steel. The belts  45  and  65  are approximately 1 inch in diameter, they have a circular cross-section and are made of a flexible material that has a high coefficient of friction and some degree of resiliency, preferably urathene. 
     As best seen in FIG. 4, support pulley  44   a  and support pulley  44   f  that is not shown, have a groove of semi-circular cross-sectional shape within which the belt  65  is received. Support pulleys  44   b ,  44   c , and support pulleys  44   d  and  44   e  that are not shown in FIG. 4, have an arch-shaped recess along their peripheral edge within which belts  45  and  65  are fitted. Thus, the belts  45  and  65  project outward beyond the surface of the pulley. This allows the surfaces of the belts to engage the side walls of the containers while providing a sufficient clearance between the container  2  and the main surfaces of the support pulleys  44 . The belts  45  and  65  are held in place on the shallow arch-shaped recesses by virtue of the tension built into the belts. It is therefore desirable to install the belts  45  and  65  tightly to avoid any accidental disengagement of the belts from the pulleys. It should also be noted that the pulleys  44   c ,  44   b ,  44   d  and  44   e  are configured to provide L-shaped recesses  83  in which the containers can fit while passing through the pulleys. 
     Horizontal shaft  49  that supports pulleys  44   a ,  44   b  and  44   c  is mounted for rotation to the frame  90  in two support bearings  91  and it is driven by a transmission  42 . The transmission  42  may include gears, belts and/or chains that transmit power from an electric motor (not shown in the drawings) to the shaft  49 . The structure of the transmission will not be described with more details because it is of conventional construction. 
     Support pulley  44   a  rotates freely about a bearing  92  that is secured to the shaft  49 . This arrangement thus allows a relative angular movement between the pulley  44   a  and the shaft  49 . Support pulley  44   b  is keyed to the shaft  49  which causes the pulley  44   b  to rotate with the shaft  49 . In other words, the pulley  44   b  is locked against any angular movement relative to the shaft  49 . Support pulley  44   c  is also driven by the shaft  49 , but is adjustable along the longitudinal axis of the shaft. This is achieved by fastening support pulley  44   c  to a projecting flange portion  96  of a collar  98 . The collar  98  is capable of sliding along the shaft  49  but not turning thereon. This can be achieved by forming on the surface of the shaft  49  an elongated keyway  94  in which is slidingly received a key (not shown in the drawings) projecting in the bore of the collar  98  in which the shaft  49  is fitted. This arrangement allows varying the longitudinal position of the pulley  44   c  on the shaft  49  while causing the pulley  44   c  to turn when a rotational movement is imparted to the shaft  49 . The collar  98  is mounted to a plate  66  that can be displaced to produce the longitudinal movement of the collar. 
     Support pulleys  44   e  and  44   f  both freely rotate on their respective bearings (not shown in the drawings but identical to the bearings  92 ) about the horizontal shaft  47  that itself is capable of free rotation in two support bearings (not shown in the drawings but identical to the bearings  91 ) mounted to the frame  90  of the apparatus  10 . Support pulley  44   d  rotates freely about shaft  47  and is secured by a collar  100  allowing to move the pulley  44   d  to move longitudinally along shaft  47 . Contrary to the collar  98 , the collar  100  is not keyed to the shaft  47  as it is allowed to freely rotate on the shaft. Also note that the collar  100  is mounted to the plate  66 . 
     As best seen in FIG. 2, a handle portion  61  of the adjustable screw  60  moves the plate  66  along supporting guides  68  to displace collars  98  and  100  and correspondingly pulleys  44   c  and  44   d  along their respective shafts. In effect, this moves belt  45  to a desired distance apart from belt  65 , thus allowing adjustment of the inter-belt distance to set the transport system for a particular container width. 
     As is best seen in FIG. 3, an air jet system  50  is provided comprising a housing  52 , a supply conduit  54  and a series of nozzles  56 . The housing contains a suitable device known by those skilled in the art to ionize air and propel it through supply conduit  54  and out through nozzles  56 . The housing  52  is mounted to the frame  90  of the apparatus by any appropriate means, such as bolts and the supply conduit  54  extends from the housing through an aperture in a funnel shaped conduit  74  having an open top in which a zone of low pressure is created. The low pressure zone is created by a suction device or vacuum port  70  known by those skilled in the art to suck air from the open top wall of the funnel shaped conduit. 
     As best seen in FIGS. 2 and 3, the final container return station  80  is a mirror image of the container pick-up station. It comprises a rotating table  30  with a circular base  32  and hub  34  through which a shaft  38  is keyed and mounted for rotation on two bearings (not shown in the drawings). A pulley  62  is mounted to the top portion of the shaft  38  and a belt  65 , positioned within a groove in the pulley, drives the pulley so as to rotate table  30 . A guide panel  22  extends across the width of the conveyor belt  6  at a preferred angle of  45  degrees with respect to the longitudinal axis of the conveyor. The guide panel  22 , together with a floor panel or bottom plate  26  and a side guide or panel  28  all assist in directing the containers  2  smoothly onto the conveyor belt  6 . 
     In operation, the portable cleaning apparatus  10  is installed alongside the conveyor belt  6  on which upright containers  2  are transported. The guide panel  22  of the container pick-up station intercepts the containers  2  on the conveyor belt  6  and directs them onto the counterclockwise rotating table  30  that feeds them to an entry zone of the internal container transport system  40  (between two belts  45  and  65 ). The rotating table  30 , with the assistance of the guide panel  22 , reverses the movement of the incoming container  2  so it is caused to travel in a direction opposite to that on the conveyor belt  6 . 
     The rotating table  30  directs the container  2  to an entry zone of the container transport system  40  comprising two resilient belts  45  and  65  which run alongside one another at one container width apart. The belts grasp the oncoming container  2  and transport the container along a first run where it follows a semi-circular path around pulleys  44   b  and  44   c , so as to be inverted with its mouth facing down. The container, in its inverted position, is then transported along a second straight run where it passes over the funnel conduit  74  and is subjected to a powerful spray of ionized air generated by the series of nozzles  56 . The ionized air enters the mouth of container  2  and neutralizes electrostatic charges on its inner walls. This prevents particulate contaminants, such as dust particles, from electrostatically clinging onto the walls of the container. The mechanical agitation generated by the turbulent air flow also places the contaminants into suspension. When the container is located between adjacent nozzles  56  it is subjected to the negative pressure zone established within the funnel by the suction device or vacuum port  70 . At that point, particulate contaminants placed in suspension are sucked out. Thus, every time the container passes over a nozzle it is subjected to a blast of ionized air and immediately afterwards to suction. This provides a plurality of blast/suction cycles that contribute to thoroughly clean each container. 
     The container which is now free of contaminants is transported along a third run where it follows a semi-circular path around support pulleys  44   d  and  44   e  so as to be oriented with its mouth facing up. The container is then transported to a final transport zone where it is released onto the container return station. The container return station comprises the second counterclockwise rotating table  30  which, with the assistance of the guide panel  22 , directs the container onto the conveyor belt  6 . 
     The transmission system  42  provides a synchronized, linear relationship between the speed of the conveyor belt  6  and the speed of the cleaning apparatus  10 . In short, an electric motor transmits rotation power to a transmission  42  connected to shaft  49 . Shaft  49  turns support pulleys  44   b  and  44   c  which respectively drive the belts  65  and  45 . More specifically, driven belt  65  which extends along a predetermined path traced by pulleys  62 , 44   a ,  44   b ,  44   f  and  44   e , rotates pulleys  62  which in effect, rotates tables  30 . Moreover, driven belt  45 , which extends along a path traced by pulleys  44   c  and  44   d , provides a side support along which to transport the container  2  through three runs. Both belts move at the same linear speed. 
     In a variant, the tables  30  may be driven by a friction wheel rather than by pulleys  62 . More specifically as best seen in figure  5 , a friction wheel  110  is provided to engage the periphery of both tables  30 . The pulleys  62  are modified to turn freely on the shaft  38  rather than being keyed to them. The belt  65  is re-routed so as to rotate a pulley  104  which is keyed to a shaft  106  that rotates the friction wheel  110 . Two idler wheels  108  guide the belt  65  and provide the appropriate tension so as to grip pulley  104  and prevent slippage thereon. As the pulley  104  turns, it drives the friction wheel  110  that, in turn, causes both tables to rotate at a peripheral linear speed identical to the peripheral linear speed of the friction wheel  110 . 
     The above description of a preferred embodiment of the invention should not be interpreted in any limiting manner as refinements and variations are possible without departing from the spirit of the invention. The scope of the invention is defined in the appended claims and their equivalents.