Patent Document

BACKGROUND OF THE INVENTION 
   (1) Field of the Invention 
   This invention provides an apparatus and method for cleaning conveyor tables used in commercial applications. The cleaning apparatus is intended for cleaning and sanitizing conveyor belts used in supermarkets and other retail outlets. The apparatus reduces cross-contamination of food products, and has minimal maintenance requirements. This novel cleaning apparatus is mountable on existing conveyor tables currently used in supermarkets, and includes a self-cleaning feature of the conveyor belt using disposable towels that reduces downtime and improves worker productivity. The cleaning apparatus can be intermittently started and stopped and can also be operated during check-out to avoid customer inconvenience. 
   (2) Description of the Prior Art 
   Conveyor tables are used extensively at check-out counters in supermarkets and other retail store outlets. A variety of products such as food products are usually placed on a conveyor. During customer check-out leakage and spillage can cross-contaminate other products, particularly food products. Large retail outlets also sell goods such as insecticides, automotive oil products, garden products and the like that can further contaminate other products and possibly endanger public health. Generally it is the responsibility of the check-out clerk to ensure that the conveyor table is manually cleaned periodically. This requires applying a detergent and/or antibacterial solution and removing the contaminated materials, such as by hand cleaning using a paper towel. These frequent cleanings result in lost productivity and more importantly may not result in thorough cleaning and sanitizing of the conveyor belt. During rush hours when customer traffic is high, it is difficult to consistently maintain a clean conveyor belt. 
   Several methods for cleaning a conveyor belt have been reported in the literature. For example, in U.S. Pat. No. 5,372,243 to King a pneumatically controlled system is used to replace an electrically controlled cleaning system. The system is designed to apply a cleaning solution with a rinse cycle through a series of nozzles positioned between the belts and have a multiple of zones. The process can be repeated using timers. The invention is intended to reduce the amount of labor to service the equipment and the amount of cleaning compound needed to clean the conveyor belt for the food and packaging industry. Another apparatus and method for cleaning conveyor belts is described in U.S. Pat. No. 5,613,594 to Kootsouradis in which a number of embodiments are described for a cleaning apparatus. A plurality of belt treatment apparatus having spray nozzles are used to apply a treatment fluid to the belt as the belt passes through the cleaning chambers while entrance and exit diverts are used to contain the cleaning fluids. The apparatus and method do not address the cleaning procedure for cleaning the chambers. In still another patent, U.S. Pat. No. 5,746,302, conveyor cleaning assemblies are described in which cleaning brushes and scrapers are used to remove debris such as occurs in food manufacturing. The brushes are designed for easy cleaning which appears to be an independent cleaning step. 
   The above apparatus and methods appear to require a separate cleaning procedure which will result in extra maintenance cost and reduced productivity. Further, the cost and complexity of installing the cleaning apparatus appears to be significant. Therefore there is still a strong need in the consumer service industry for a self-cleaning conveyor apparatus with easily replaced cleaning parts and which requires minimal downtime. The cleaning apparatus should also be mountable on existing conveyor tables with minimal time and cost. 
   SUMMARY OF THE INVENTION 
   A principal object of the present invention is to provide a conveyor cleaning apparatus and method for cleaning commercial conveyor tables. 
   A second object of this invention is to provide a conveyor cleaning apparatus that is self-cleaning using a wiping device and a disposable towel for reduced maintenance and increased productivity. 
   A third object of this invention is to provide a conveyor cleaning apparatus which is easy to remove and attachable (mountable) to the conveyor table for easy servicing of both the conveyor table and cleaning apparatus with minimal downtime. 
   A fourth object of this invention by a second embodiment is to provide a wiping device which uses a wet wipe that is easy to remove. 
   In accordance with the present invention a conveyor cleaning apparatus and method are described for use on a commercial conveyor table such as those used in most large grocery stores, supermarkets, and retail outlets. The apparatus is comprised of a metal or plastic housing that extends across and under or over a (minor) portion of the conveyor belt and is normal (at a right angle) to the conveyor belt&#39;s direction of motion (V) to provide a cleaning chamber. At least one spraying tube extends through an opening in a first side of the housing and extends over the conveyor belt to a second side of the housing. The spraying tube is in proximity to the conveyor belt with an array of orifices across the tube that extends in the direction of the conveyor belt to direct a cleaning solution (S) onto the conveyor belt. A wiping device is also included within the housing. A novel feature of the invention is that the wiping device has at least one disposable towel and extends across and normal to the conveyor belt&#39;s direction (V) for removal of the cleaning solution (S) and any included contaminants by the disposable towel. During operation of the conveyor belt cleaning apparatus, a cleaning and disinfectant solution is sprayed onto the conveyor belt and a disposable towel is then applied to the belt to remove the cleaning solution and any contaminants using the wiping device. When the cleaning apparatus is mounted under and in contact with the conveyor belt, after one complete cycle of the conveyor belt the used disposable towel is released (by gravity) into a container. If the cleaning apparatus is mounted on the top surface of the conveyor belt, then the used disposable towel is released and allowed to continue down the conveyor belt to be disposed of by the check-out clerk (cashier). Alternatively a capturing device can be included in the housing to capture and dispose of the soiled towel. 
   By a second embodiment, a disposable wet-wipe towel device can be incorporated in the wiping device to clean and disinfect the conveyor belt thereby eliminating the need for the spraying mechanism and simplifying the cleaning process and manufacturing cost. In this second method the wet-wipe disposable towel can be replaced after a predetermined number of cleaning cycles of the conveyor belt. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a schematic top view of a portion of a conveyor belt with this novel cleaning apparatus that uses a spraying tube and a wiping device with a disposable towel mounted on the bottom side of the conveyor belt by a first embodiment. 
       FIG. 2  shows a schematic cross-sectional view of a portion of a conveyor belt showing the cleaning apparatus in  FIG. 1 , and depicting the essential operating parts. 
       FIG. 3  shows a schematic top view of a conveyor belt with this novel cleaning apparatus using a wiping device having a wet wipe, which eliminates the need for a spraying tube and disposable towel, mounted on the bottom side of the conveyor belt by a second embodiment. 
       FIG. 4  shows a schematic cross-sectional view of a portion of the conveyor belt having the cleaning apparatus in  FIG. 3 , and depicting the essential operating parts. 
       FIG. 5  shows a schematic top view of a conveyor belt with this novel cleaning apparatus mounted on the bottom side of the conveyor belt using a mechanical means for applying the wiping device to the conveyor belt for the second embodiment. 
       FIG. 6  shows a schematic cross-sectional view of a portion of the conveyor belt having the cleaning apparatus in  FIG. 5 , for applying a mechanical means to engage the wiping device with the conveyor belt. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   In accordance with the present invention a novel cleaning apparatus on a conveyor belt and method are described for use on a commercial conveyor table used in most supermarkets. 
   Referring to  FIG. 1 , a top view is shown of a portion of a conveyor table  4  having a continuous conveyor belt  8  in which the novel conveyor cleaning apparatus  12  is depicted. The cleaning apparatus  12  is mounted under the conveyor belt  8  at the end of the belt  8  and near the check-out counter (optical scanner) (not shown) so that a check-out clerk can conveniently operate the cleaning apparatus  12  manually while serving the customer. However, it should be understood that the cleaning apparatus  12  can be mounted anywhere on the conveyor table  4 , and remotely controlled using an electrical and/or hydraulic servo system to operate the cleaning apparatus  12 . 
   The cleaning apparatus  12  is encased in a housing  10 , made, for example, of metal, plastic, and the like, that extends under and across a (minor) portion of the conveyor belt  8  and is normal (at a right angle) to the direction of motion of the conveyor belt  8 , as depicted by the arrow V in both  FIGS. 1 and 2 . The housing  10  is preferably mounted by providing a bracket  17  (shown in  FIG. 2 ) in the conveyor table  4  next to the crumb tray  9  in which the housing can be easily inserted and secured. However, it should be understood by those skilled in the art that the housing can be directly mounted to the conveyor table  4 , for example by modifying the conveyor table  4  and using bolts, as shown in  FIG. 2 . The details of mounting the housing are not shown to simplify the drawings and because the mounting is by conventional means. 
   Still referring to  FIG. 1 , at least one spray tube  14  extends through an opening  18  in a first side  20  of the housing  10  and extending across and under the conveyor belt  8  to a second side  22  of the housing  10 . A cleaning solution S is injected into the spray tube  14  from a manually pressurized solution container (not shown) and a shut-off valve  19  between the container and the spray tube  14 . The valve  19  can also be automated using servo-mechanism. The wiping device  24  is also mounted in the housing  10  adjacent to the spray tube  14 . The wiping device  24  also includes a separate flexible sleeve  30  to improve the wiping effectiveness and for servicing, but the sleeve  30  can also be an integral part of the wiping device  24 . 
   Referring to  FIG. 2 , a schematic cross-sectional side view is shown for the cross section through  1 – 1 ′ of  FIG. 1  to better appreciate and to describe in more detail the cleaning apparatus  12 . The spraying tube  14  is in proximity to the conveyor belt  8 , and the spraying tube  14  includes an array of orifices (openings)  16  across the spraying tube that extend upward to direct a cleaning solution S onto the conveyor belt  8 . 
   Still referring to  FIG. 2 , a novel feature of the invention is to provide a wiping device  24  in the housing  10  having one or more disposable towels  26  positioned between the wiping device  24  and the conveyor belt  8 . The wiping device  24  extends across and normal to the direction of motion V of the conveyor belt  8 . The wiping device  24  is supported by and between the front portion  20  and the back portion  22  of the housing  10  (see  FIG. 1 ), but is free to move up and down, as depicted by the arrow  11 , to engage the conveyor belt  8  and also to rotate with an angular speed ω to provide a wiping action with the disposable towel  26 . Although the towels  26  are depicted as a stack, it should be understood that they can be dispensed by some other means, such as from a roll. During operation of the conveyor belt cleaning apparatus  12 , a cleaning and disinfectant solution S is sprayed onto the conveyor belt and concurrently a disposable towel  26  is applied to the belt to remove the cleaning solution and any contaminants. The wiping device  24  is preferably a cylinder composed of a material such as aluminum, hard plastic, and the like, and the outer flexible sleeve  30  is formed from a soft, non-absorbent, flexible spongy material. The wiping device  24  with the flexible sleeve  30  is designed to provide a static frictional force F static  between the flexible sleeve and the disposable towel, where F static  is greater than the sliding frictional force F sliding  between the conveyor belt  8  and the disposable towel  26  when the conveyor belt is in motion. The wiping device (cylinder)  24  with sleeve  30  having a radius R 2  is made to rotate through a linear distance that is less than the distance the conveyor belt  8  rotates R 2  through. By way of example only, if the cylindrical wiping device  24  has a radius R 2  of 1.0 inches and if the conveyor-belt roller radius R 1  is 12.0 inches, then for every 12.0 inches the conveyor belt  8  advances, the disposable towel  26  advances by one inch. For example, if the total length of the conveyor belt  8  is 12 feet, then to clean the conveyor belt would require 12 inches of disposable towel  26 . It should also be clear that by using reducing gears and the like, the ratio of R 2  to R 1  can be optimized to minimize the use of the disposable towel  26 . The disposable towel is preferably paper. 
   Although the cleaning apparatus is preferably mounted as above, it should be understood that it can also be mounted elsewhere on the conveyor table  4 , such as over or on the opposite side of the table  4  (not shown). In this configuration after one complete cleaning cycle of the conveyor belt, a disposable towel can be released to continue down the conveyor belt to be disposed of by the check-out clerk (cashier), or alternatively a capturing device can be included in the housing to remove and dispose of the soiled disposable towel. 
   Referring to  FIG. 3  and  FIG. 4 , a top view and a cross-sectional schematic view, respectively, are shown for a second embodiment. In this cleaning apparatus the spray tube  14  (shown in  FIGS. 1 and 2 ) is eliminated, and the wiping device  26  with sleeve  30  uses a disposable towel  27  that contains a cleaning solution (wet-wipe towel) that is used to clean and disinfect the conveyor belt  8 . This configuration eliminates the need for the spraying mechanism and simplifies the cleaning process and reduces manufacturing cost. In this second method the wet-wipe disposable towel can be replaced after a predetermined number of cleaning cycles of the conveyor belt. 
   Referring to  FIGS. 5 and 6 , a mechanical means and method are described for engaging the wiping device  26  for the cleaning apparatus  12  of the first and second embodiments. The mechanical means of engaging the cleaning apparatus can be achieved manually, as described below. A manual operation provides a cost-effective method for cleaning the conveyor belt  8 , but it should be understood that the conveyor belt cleaning apparatus  12  can be modified using electrical and/or hydraulic systems, for example by using a microprocessor to fully automate this novel cleaning apparatus  12 . This automation improves productivity by freeing up the check-out clerk, but is more costly to install. However, an automated cleaning apparatus is advantageous at self-check stations where check-out clerks are not required. 
   Referring to  FIG. 5 , a schematic top view of the conveyor table  4  is shown. The drawing is for the second embodiment which does not include the spray tube  14 , therefore, it simplifies the drawing, but the mechanical means for engaging the wiping device  24  would be the same as in the first embodiment. As shown in  FIG. 5 , a lever  34  is attached to the wiping device  24  at a point  31 , and the lever is rotated around a shaft  36  to engage the wiping device  24 . The wiping device is engaged and disengaged by moving the lever  34  in an up and down position, as indicated by the double-headed arrow D (see  FIG. 6 ), to make contact with the conveyer belt  8 . The mechanical means can include a locking device (not shown) that releases the wiping device  24  after a predetermined cycle of the conveyor belt  8 . The details are not shown, but this cleaning apparatus could be automated, for example, by using an electric and/or hydraulic servo system. 
     FIG. 6  shows a cross section through the region  5 – 5 ′ of  FIG. 5 .  FIG. 6  also shows superimposed on the cross section through  5 – 5 ′ the lever  34  for raising and lowering the wiping device  24  (with flexible sleeve  30 ) a distance D to apply the wet-wipe disposable towel  27 . Although the lever  34  is shown for the second embodiment, to simplify the drawings, the lever is also applicable to the first embodiment which includes the spraying tube  14 . Also shown in  FIGS. 4 and 6  is an optional roller  32  that supports the conveyor belt during cleaning. 
   While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.

Technology Category: 7