Patent Publication Number: US-2006011220-A1

Title: Shopping cart wash tunnel

Description:
This application claims priority from U.S. provisional application Ser. No. 60/588,058, the disclosure of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD  
      The present invention relates to an apparatus and method for sanitizing shopping carts.  
     BACKGROUND OF THE INVENTION  
      A shopping cart, and particularly a shopping cart used in a grocery or discount store, will be used many times per day. With each use, there is a significant opportunity for contamination of the cart with germs that can lead to the spread of disease. Examples of such diseases may include the common cold and influenza viruses, as well as food-borne illnesses including  escherichia coli  and  salmonella.    
      A typical shopping cart has at least one basket for carrying items, four wheels to transport the cart, and a handle to push or pull the cart. Many carts have a child seat facing the handle. Shopping carts often nest together so that multiple carts can be moved and stored together.  
      A shopping cart encounters several sources of germs, and the contamination opportunities are centered on several parts of the cart. A primary area of contamination is the handle. First, the customer who is handling food products and merchandise continually touches the handle. Second, child passengers face the handle when placed in the child seat that is conventional on many shopping carts. These child passengers grasp the handle and are also known to bite or drool on the handle. A second area of contamination is the child seat itself, which may be contaminated by the child passengers. A third area of contamination is the basket of the cart. Uncooked meat and poultry items, unwashed fruits and vegetables and plant items are commonly transported in this portion of the shopping cart. Furthermore, the carts do not remain in the store at all times, and they are exposed to a number of contaminates in every trip to the store parking lot. Examples of such contaminates include petroleum based pollutants from automobile exhaust, factory emissions from surrounding industrial sites, road dirt, droppings from birds and other grime.  
      As shopping cart contamination is a public health concern, there have been some efforts in the field of shopping cart sanitation. Some recent United States patents and published patent applications have focused almost exclusively on the handle. For example, U.S. Pat. No. 5,215,319 to Farris, U.S. Pat. No. 6,065,764 to Moseley, and U.S. published application 2004/0021279 to Sobo all provide sanitary covers for the handle. U.S. Pat. No. 6,129,417 to Cohen-Fyffe teaches a seat cover for the shopping cart child seat area. Additionally, various retailers provide disinfectant wipes to their customers. Some commercial cleaning service companies offer cart cleaning to the retailer using portable pressure washers. However, seat and handle covers become dirty from the cart and must be replaced or washed after each use. Wipes are costly and only locally effective if used properly. Not all customers use covers and wipes, and not all retailers can afford to offer them. The effectiveness of commercial cleaning services varies with the operator. Additionally, commercial cleaning services may be infrequently used, allowing germs and grime to build up. While all of these efforts to reduce the spread of disease via shopping carts have furthered the art of cart sanitation, none of the known prior art addresses sanitation of the entire cart in a regular and convenient way. There remains a need for a convenient and thorough cleaning system and method for sanitizing shopping carts.  
     SUMMARY OF THE INVENTION  
      In response to the foregoing concerns, the present invention provides a method and apparatus for sanitizing shopping carts. One embodiment of the cart sanitizing system comprises a wash tunnel, having a first end and a second end. The wash tunnel has a means for conveying the shopping carts from the first end to exit through the second end. The present invention further includes means for detecting the position of the shopping carts within the wash tunnel, and an array of nozzles connected to at least one source of fluid for sanitizing the shopping carts. The apparatus includes means for controlling the array of nozzles; wherein the fluid sprays from the array of nozzles when the shopping carts convey under the array of nozzles.  
      The wash tunnel includes components designed to effectively sanitize shopping carts as the shopping carts pass through the wash tunnel. In one embodiment, the wash tunnel comprises a soap spray, rinse spray, a dryer, and optionally, disinfectant spray. The method of sanitizing shopping carts comprises propelling a plurality of shopping carts through a wash tunnel through a soap spray and a rinse spray. The method may further comprise propelling the shopping carts through a disinfectant spray and a continuous stream of drying air.  
      In an alternate embodiment, the shopping carts remain stationary while being sanitized. In this alternate embodiment, the wash tunnel comprises a spray gantry that moves along gantry tracks positioned inside the wash tunnel so that the spray gantry travels over the shopping carts as it moves along the gantry tracks inside the wash tunnel. The spray gantry comprises means for discharging spray of various solutions. The spray gantry may be programmed to operate in a wash sequence, so that soap spray is dispensed as the spray gantry passes over the shopping carts in a first pass. The spray gantry discharges a rinse spray in a second pass over the shopping carts. Optionally, the spray gantry discharges a disinfectant spray in a third pass over the shopping carts. As the shopping carts are moved out of the wash tunnel, they encounter a stream of drying air.  
      In alternate embodiments, the cart sanitizing system may include a wash tunnel installed in a cart entrance of a retail building. The wash tunnel includes a means for discharging a disinfectant spray. Shopping carts pass through the disinfectant spray as the shopping carts enter the building. Means for conveying shopping carts can be employed to keep the cart operator away from the disinfectant spray.  
      In other alternate embodiments, the cart sanitizing system includes a steam cleaning apparatus.  
      The following description sets forth in detail certain illustrative embodiments of the invention, these being indicative of but a few of the various ways in which the principles of the present invention may be employed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a side perspective view of a first embodiment of the cart sanitizing system according to the present invention;  
       FIG. 2  is an enlarged perspective view of a soap spray nozzle of a first embodiment of the cart sanitizing system;  
       FIG. 3  is an enlarged perspective view of a rinse spray nozzle of the first embodiment of the cart sanitizing system;  
       FIG. 4  is an enlarged perspective view of a disinfectant spray nozzle of the first embodiment and a third embodiment of the cart sanitizing system;  
       FIG. 5  is a side perspective view of a second embodiment of the cart sanitizing system according to the present invention;  
       FIG. 6  is an enlarged perspective view of a spray nozzle on the spray gantry of the second embodiment of the cart sanitizing system;  
       FIG. 7  is a side perspective view of the third embodiment of the cart sanitizing system;  
       FIG. 8  is a side perspective view of a fourth embodiment of the cart sanitizing system according to the present invention;  
       FIG. 9  is an enlarged perspective view of a steam nozzle of the fourth embodiment of the cart sanitizing system;  
       FIG. 10  is a flow chart of a steam cleaning apparatus of the fourth embodiment of the cart sanitizing system; and  
       FIG. 11  is a side view of a means for conveying shopping carts according to the fourth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION  
      A first embodiment of a wash tunnel  1  is illustrated in  FIG. 1 . The wash tunnel  1  has a first end  2  and a second end  4  and is sized to accommodate a plurality of shopping carts  6 . Shopping carts  6  enter the wash tunnel  1  through the first end  2 , travel through the wash tunnel  1  and exit the wash tunnel  1  by passing through the second end  4 . The wash tunnel  1  is sized to allow shopping carts  6  to easily pass through the wash tunnel  1 . Optionally, the wash tunnel  1  may be large enough for a person to walk through in order to perform maintenance or other operations. The length of the wash tunnel  1  may be sufficient to dispense a soap spray  8 , a rinse spray  10 , a disinfectant spray  12 , and a continuous sheet of high-velocity air  14 , each separated a distance sufficient to substantially prevent mixing.  
      The plurality of shopping carts  6  may be automatically propelled through the wash tunnel  1 . Means for conveying the plurality of shopping carts will herein be represented as conveyor  16 , and include, but are not limited to a conveyor belt, such as those well known in the art, wherein the belt is made from leather, rubber, wire mesh, chain link, or any other man-made or synthetic material. Another means for conveying includes a guided push/pull chain, and similar configurations well known in the art. Another means for conveying includes a continuous screw shaft, wherein a motor rotates the continuous screw shaft, causing an operably connected push arm to translate along the continuous screw shaft, further discussed below. The use of continuous screw shafts for conveying is well known in the art. Means for conveying the plurality of shopping carts as contemplated herein includes any known device for automatically pulling or pushing the shopping carts  6  through and/or out of the wash tunnel  1 .  
      The conveyor  16  extends longitudinally through the wash tunnel  1  from the first end  2  to the second end  4 . In the embodiment illustrated in  FIG. 1 , the conveyor  16  has a length longer than the length of the wash tunnel  1  such that the conveyor  16  extends beyond the first end  2  and the second end  4  of the wash tunnel  1 . In this embodiment, the conveyor  16  moves at a uniform rate, carrying the shopping carts  6  through the wash tunnel  1 .  
      Inside the wash tunnel  1 , the shopping carts  6  are conveyed through the soap spray  8  dispensed by a soap delivery apparatus  18 . With reference to  FIG. 2 , the soap delivery apparatus  18  is an aqueous system that dispenses the soap spray  8  from one or more nozzles  20  in a vertical and/or transverse direction. The soap delivery apparatus  18  comprises a source of soap, and further comprises valves, pumps, pipes or tubes, and other traditional and typical fluid handling components all well known in the art, arranged to deliver soap from the source of soap to the nozzles  20 . In this embodiment, the soap spray  8  is a high-pressure spray, but in alternate embodiments, the soap spray  8  can be a low-pressure spray or foam.  
      As used in this written description and in the attached claims, the word “soap” is not limited to traditional salts of fatty acids as used for cleaning. As used herein, “soap” includes natural and synthetic cleaning and wetting soaps, detergents, and surfactants, in a state suitable for spraying.  
      As used in this written description and in the attached claims, the word “fluid” is not limited to liquid substances. As used herein, “fluid” includes any substance in a liquid, gas or vapor, powder, or other state suitable for spraying.  
      After the shopping carts  6  pass through the soap spray  8 , the shopping carts are conveyed through a rinse spray  10 , dispensed by a rinse delivery apparatus  22 . The rinse delivery apparatus  22  dispenses rinse spray  10  from one or more nozzles  24  in a vertical and/or transverse direction. The rinse delivery apparatus  22  comprises a source of water or other rinsing agents, and further comprises valves, pumps, pipes or tubes, and other traditional and typical fluid handling components all well known in the art, arranged to deliver the water or other rinsing agents from the source to the nozzles  20 . With reference to  FIG. 3 , the rinse spray  10  is a high-pressure water spray. Alternately, the rinse spray  10  may be a low-pressure spray, and/or may employ chemical rinsing agents.  
      After passing through the rinse spray  10 , the shopping carts  6  preferably continue on the conveyor  16  through the disinfectant spray  12 , delivered by a disinfectant delivery apparatus  26 . In one embodiment, the disinfectant delivery apparatus  26  dispenses disinfectant spray  12  through one or more nozzles  28 , as illustrated in  FIG. 4 . The disinfectant spray  12  may be a low-pressure spray. Disinfectant spray  12  can be any disinfecting or sanitizing agent suitable for spray application. Disinfecting and sanitizing agents are well known in the art.  
      The disinfectant delivery apparatus  26  comprises a source of disinfectant, and further comprises valves, pumps, pipes or tubes, and other traditional and typical fluid handling components all well known in the art, arranged to deliver the disinfectant from the source of disinfectant to the nozzles  20 .  
      Vent  30  may be provided to remove disinfectant fumes from the wash tunnel  1  for safe application of the disinfectant spray  12 . Alternate embodiments may omit the disinfectant spray  12 .  
      Before exiting the tunnel at the second end  4 , the shopping carts  6  are conveyed near a dryer  32 . The dryer  32  may be a conventional forced air blower that discharges the continuous sheet of high-velocity air  14  to blow the water off of the shopping carts  6  as they pass by. Such dryers  32  are often called air knives and are well known in the art. Optionally, the continuous sheet of high-velocity air  14  may be heated for faster drying.  
      One or more of the sprays dispensed in the wash tunnel preferably activates automatically, as described below.  
      The system disclosed in the first embodiment may be used with a method of sanitizing shopping carts  6 . The method comprises propelling a plurality of shopping carts  6  through a wash tunnel  1 , passing the shopping carts  6  through an automatically activated soap spray  8 , rinse spray  10 , disinfectant spray  12 , and a continuous sheet of high-velocity air  14 .  
      A second embodiment of a wash tunnel  1  is illustrated in  FIG. 5 . In the second embodiment, the wash tunnel  1  has a first end  2  and a second end  4  and is sized to hold a plurality of shopping carts  6 . Shopping carts  6  enter the wash tunnel  1  through the first end  2 , travel through the wash tunnel  1  and exit by passing through the second end  4 . The wash tunnel  1  length is sufficient to hold a predetermined number of shopping carts  6 . The wash tunnel  1  height and width is sized for shopping carts  6  to easily pass through with further space toward the top and sides to accommodate the operation of a spray gantry  34 . Gantry tracks  36  extend through the length of the wash tunnel  1  in a direction parallel to the direction of movement of the shopping carts  6 . In one embodiment, the gantry tracks  36  are located on the floor, one on the left side and one on the right side. Optionally, the gantry tracks  36  are mounted on the ceiling, or on the sidewalls. If installed on the ceiling, a gantry track  36  may be center mounted. The gantry tracks  36  may have a start position  38  and a return position  40 . The spray gantry  34  moves along the gantry tracks  36  from the start position  38  near the first end  2  to the return position  40  near the second end  4 . It is contemplated that the start position  38  and return position  40  may be located at any two positions within the wash tunnel  1  or may be at the same position.  
      The spray gantry  34  comprises means for dispensing spray  42  from one or more nozzles  44 . Means for dispensing spray comprises at least one source of fluid, and further comprises valves, pumps, pipes or tubes, and other traditional and typical fluid handling components all well known in the art, arranged to deliver the fluid from the source of fluid to the nozzles  44 . The nozzles  44  are distributed around the spray gantry  34  positioned to dispense spray  42  in a vertical and/or transverse direction. The spray gantry  34  comprises control means for sequentially altering the composition of spray  42  to be soap solution, rinse solution, or disinfectant. Control means for sequentially altering the composition of spray  42  comprises a computer or other programmable controller controlling at least one valve in communication with said at least one source of fluid. Control means such as these are well known in the art, and may be programmed as described below. Various embodiments of spray  42  could use high-pressure, low-pressure, foam, or combinations thereof. Optionally, different compositions of spray  42  can be discharged out of separate corresponding sets of nozzles  44 .  
      Mounted near the second end  4  is a dryer  32 . The dryer  32  may be a conventional forced air blower that delivers a continuous sheet of high-velocity air  14  to blow the water off of the shopping carts  6  as they exit the wash tunnel  1 . Such dryers  32  are often called air knives and are well known in the art. Optionally, the continuous sheet of high-velocity air  14  may be heated for faster drying. In an alternate embodiment, dryer  32  may be ducted into the wash tunnel to dry the shopping carts  6  before they are conveyed out of the wash tunnel  1 .  
      The spray gantry  34  is programmed to operate in a wash sequence. First, an operator places shopping carts  6  in the wash tunnel  1  through the first end  2 . Upon activation, the spray gantry  34  moves along the gantry tracks  36  from the start position  38  to the return position  40  while spray  42  is dispensing soap solution. Upon reaching the return position  40 , the spray gantry  34  may switch the composition of spray  42  to a rinse solution, which may be water in this embodiment. The spray gantry  34  moves from the return position  40  to the start position  38  while spray  42  discharges rinse solution. Upon reaching the start position  38 , the spray gantry  34  may change the composition of spray  42  to a disinfectant. The spray gantry  34  then moves from the start position  38  to the return position  40  while spray  42  is dispensing disinfectant. Disinfectant spray  42  can be any disinfecting or sanitizing agent suitable for spray application. Alternate embodiments may omit dispensing a disinfectant, or may change the order in which the fluids are dispensed. When the spray gantry  34  reaches the return position  40  after dispensing disinfectant, the spray gantry  34  can return to the start position  38 . Vent  30  may be provided to remove fumes from the wash tunnel  1  for safe application of the disinfectant. An operator then pushes the shopping carts  6  out through the second end  4  while the dryer  32  is activated. In alternate embodiments, automated means for conveying the plurality of shopping carts can be employed to move carts into and out of the wash tunnel  1 , such as conveyor  16  or other devices as discussed above. Optionally, the carts can enter the wash tunnel  1  and exit the wash tunnel  1  through the first end  2 , in which case the dryer  32  is mounted near the first end  2 . In further embodiments of the cart sanitizing system, spray  42  is steam.  
      The system disclosed in the second embodiment may be used with a method of sanitizing shopping carts. The method comprises placing shopping carts  6  in a wash tunnel  1 , and programming a spray gantry  34  to pass repeatedly over the carts dispensing a spray  42 , where in the first pass spray  42  comprises a soap solution, in the second pass spray  42  comprises a rinse solution, and in a third pass, spray  42  comprises a disinfectant; and passing the shopping carts  6  under a continuous sheet of high-velocity air  14  upon exit from the wash tunnel  1 .  
      A third embodiment of the cart sanitizing system is shown in  FIG. 7 . The wash tunnel  1  is installed in a cart entrance  46  of a retail building  48 . The wash tunnel  1  comprises the disinfectant delivery apparatus  26  that dispenses disinfectant spray  12  through one or more nozzles  28 , as illustrated in  FIG. 4 . Shopping carts  6  pass through the disinfectant spray  12  as they enter the retail building  48 . In one embodiment, cart moving means  50  are employed to keep the cart operator away from the disinfectant spray  12 . The cart moving means  50  utilize a conveyor  16  in this embodiment, but any means for conveying a plurality of shopping carts could readily be adapted, as discussed above.  
      It is contemplated that the third embodiment through the wall of a retail building could employ the first embodiment or the second embodiment of the present invention. Alternate embodiments could dispense additional sprays, such as a rinse and/or dry.  
      The system disclosed in the third embodiment may be used with a method of sanitizing shopping carts. The method comprises propelling a plurality of shopping carts  6  through a wash tunnel  1  and dispensing a disinfectant spray  12  over the shopping carts  6  in the wash tunnel  1 .  
      A fourth embodiment of the cart sanitizing system is shown in  FIG. 8 . The cart sanitizing system includes a wash tunnel  1  with a first end  2  and a second end  4 . The wash tunnel  1  is sized to accommodate a plurality of shopping carts  6  that enter through the first end  4  of the wash tunnel  1 . The wash tunnel  1  includes a steam cleaning apparatus  52 , well known in the art. The steam cleaning apparatus  52  is in communication with a source of water  54  that provides water  56  to the steam cleaning apparatus  52 . The water  56  passes through a means of heating  58  where it is heated to a temperature higher than the boiling point of the water  56 . In one embodiment, the means of heating  58  is an electric or gas heat exchanger designed to raise the temperature of the water  56  to higher than the boiling point of the water  56 . At the boiling point of the water  56 , the water  56  undergoes a phase change into steam  60 . A steam delivery system  62  is in communication with the means of heating  58 , and the steam  60  passes into the steam delivery system  62 . The steam delivery system  62  includes one or more nozzles  64  to direct the steam  60  onto the shopping carts  6 . In one embodiment, the steam  60  is at an elevated pressure such that the steam  60  exiting the nozzles  64  impinges onto the shopping carts  6  with force. In an alternate embodiment, the steam  60  exits the nozzles  64  at or near atmospheric pressure onto the shopping carts  6 .  
      The cart sanitizing system utilizing a steam cleaning apparatus  52  can employ conveyor  16 , or any other means for conveying a plurality of shopping carts into and/or out of the wash tunnel as described above. The shopping carts  6  can exit the wash tunnel  1  by the first end  2  or the second end  4 . In one embodiment as shown in  FIG. 11 , the means for conveying a plurality of shopping carts includes a continuous screw shaft  80  rotatably supported in the wash tunnel  1  above the shopping carts  6 . The continuous screw shaft  80  extends from the first end  2  to the second end  4 . The means for conveying a plurality of shopping carts further comprises a push arm  82 , having a driven end  84  and a pushing end  86 . The continuous screw shaft  80  comprises a screw thread along the length of the continuous screw shaft  80 , operably connected to corresponding features on the driven end  84 . A motor  88  is drivingly connected to the continuous screw shaft  80 , whereby the screw thread advances the push arm  82  along the continuous screw shaft  80  when the continuous screw shaft  80  rotates. In one embodiment, the corresponding features on the driven end  84  include an internal thread that matches the thread of the continuous screw shaft  80 . Alternately, the driven end  84  may operably connect to the continuous screw shaft  80  using any protrusion that engages the thread of the continuous screw shaft  80 . A control system allows an operator to start and stop the motor  88 . A track  90  is installed adjacent to the continuous screw shaft  80  to orient the push arm  82  as it travels between a home position  92  at the first end  2 , and a stop position  94  at the second end  4 . When the push arm  82  is at the home position  92 , the track holds the push arm  82  in a horizontal position so that the shopping carts can pass under the push arm  82 . When the motor  88  rotates the continuous screw shaft  80 , the push arm  82  begins to travel along the screw thread of the continuous screw shaft  80 . When the push arm  82  leaves its home position  92 , the track  90  allows the push arm  82  to rotate down into a vertical orientation, wherein the pushing end  86  is positioned to push against the shopping cart closest to the first end  2 . As the push arm  82  travels from the first end  2  to the second end  4 , the pushing end  86  pushes said first cart, which in turn pushes the shopping carts through the wash tunnel  1  and out through the second end  4 . When the push arm  82  reaches the stop position  94 , the motor  88  rotates in the opposite direction, causing the push arm  82  to translate along the continuous screw shaft  80  in a reverse direction from the stop position  94  to the home position  92 .  
      In one embodiment, a dryer  32  is mounted in the wash tunnel  1  to dry the shopping carts  6  as the shopping carts  6  exit the wash tunnel  1 . The dryer  32  may be a conventional forced air blower that delivers a continuous sheet of high-velocity air  14  to blow the water off of the shopping carts  6 . Such dryers  32  are often called air knives and are well known in the art. In another embodiment, the dryer  32  is ducted into the wash tunnel  1  to fill the wash tunnel  1  with a large volume of drying air before the shopping carts are conveyed out.  
      In some embodiments, it may be desirable to equip the wash tunnel  1  with doors for safety or other reasons. As illustrated in  FIG. 11 , a first door  96  substantially covers the first end, and a second door  98  substantially covers the second end. In one embodiment, the first door  96  and second door  98  lock during the wash cycle and/or when the wash tunnel  1  is not in use.  
      The system disclosed in the fourth embodiment may be used with a method of sanitizing shopping carts. The method comprises placing a plurality of shopping carts  6  in a wash tunnel  1  and then dispensing steam  60  over the shopping carts  6 .  
      The presence of shopping carts  6  in the cart sanitizing system may be monitored. By monitoring the presence of shopping carts  6 , the cart sanitizing system can be deactivated when shopping carts  6  are not present. By coordinating the operation of the cart sanitizing system to the presence of shopping carts  6 , energy costs and chemical use can be minimized. Sensing means for detecting the position of the shopping carts may include one or more proximity sensors  66  to monitor the presence or position of a shopping cart  6 . Means for detecting the position of the shopping carts will herein be referenced as proximity sensors  66 , but may include any sensor suitable for detecting the presence of the shopping carts, including but not limited to devices deploying radio frequency, light, acoustic, photoelectric, laser, magnetic, or electronic sensors, all of which are well known in the art. Sensing means for detecting the position of the shopping carts also includes physical contact switches and other physical sensing devices, which are well known in the art.  
      In the first embodiment as illustrated in  FIG. 1 , the proximity sensors  66  can be positioned at the first end  2 , between the soap spray  8  and the rinse spray  10 , between the rinse spray  12  and the disinfectant spray  14 , between the disinfectant spray  14  and the dryer  32 , and at the second end  4 . As the shopping carts  6  are conveyed through the wash tunnel  1 , the soap spray  8  activates when one or more shopping carts  6  pass the first proximity sensor  66 , and continues until the shopping carts  6  pass a second proximity sensor  68 . Likewise, the rinse spray  10  activates when the shopping carts  6  pass the second proximity sensor  68 , and continues until the shopping carts  6  pass a third proximity sensor  70 . The disinfectant spray  12  activates when the shopping carts  6  pass the third proximity sensor  70 , and continues until the shopping carts  6  pass a fourth proximity sensor  72 . Finally, the dryer  32  activates when the shopping carts  6  pass the fourth proximity sensor  72 , and continues until the shopping carts  6  pass a fifth proximity sensor  74 . Alternately, a timer could be coupled with the proximity sensor  66  to allow the cart sanitation system to activate for a sufficient duration for a shopping cart  6  to pass through the wash tunnel  1  given the uniform speed of the conveyor  16 .  
      In the second embodiment as illustrated in  FIG. 5 , a proximity sensor  66  may monitor the presence of one or more shopping carts  6 . The spray  42  would not activate when no shopping cart  6  is present to conserve water and chemicals.  
      In the third embodiment as illustrated in  FIG. 7 , a proximity sensor  66  may monitor the presence of one or more shopping carts  6 . In order to conserve disinfectant, the disinfectant spray  12  can be programmed to activate only when the conveyor  16  is moving and the proximity sensor  66  senses the presence of the shopping carts  6 .  
      In the fourth embodiment as illustrated in  FIG. 1 , the proximity sensors  66  can be positioned at the first end  2  before the steam delivery system  62 , between the steam delivery system  62  and the dryer  32 , and at the second end  4 . The steam  60  activates when one or more shopping carts  6  pass the first proximity sensor  66  and continues until the shopping carts pass the second proximity sensor  68 . The dryer  32  activates when the shopping carts  6  pass the second proximity sensor  68 , and continues until the shopping carts  6  pass a third proximity sensor  74 .  
      The cart sanitizing system dispenses chemicals or steam, and for environmental reasons the fluid dispensed by the system and the effluent from the shopping carts should be contained. The cart sanitizing system may provide a means for reclaiming fluid, comprising a means for diverting waste fluids  76  and a waste fluid reclamation unit  78 . The means for diverting waste fluids  76  comprises drains, valves, pumps, pipes or tubes, and other traditional and typical fluid handling components, all well known in the art, arranged to deliver the dispensed fluid and effluent from the wash tunnel  1  to the waste fluid reclamation unit  78 . The waste fluid reclamation unit  78  may be a collection and filtration system similar to those used in car wash or industrial water reclamation units well known in the art. In one embodiment, the waste fluid reclamation unit  78  treats the effluent and recycles it in the cart sanitizing system. Alternately, the waste fluid reclamation unit  78  collects the waste for proper disposal.  
      The cart sanitizing system can be embodied in a mobile unit for commercial cleaning services. In a mobile embodiment, the wash tunnel  1  is mounted onto a truck or trailer for convenient transporting to retail locations for cart cleaning. In a mobile unit, the conveyor  16  may be divided into sections for compact transporting.  
      The present invention provides retailers with a cart sanitation system that is so convenient and effective that it can be used to sanitize shopping carts every day. The cart sanitation system operates efficiently by washing many carts at one time and by reclaiming and recycling waste fluids. By employing the cart sanitation system, the spread of diseases via shopping carts can be reduced and the public health will benefit.  
      Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and illustrative examples shown and described herein. Accordingly, various modifications may be made without departing from the scope of the general inventive concept disclosed herein.