DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] A preferred embodiment detergent dispenser constructed according to the principles of the present invention is designated as 100 in FIGS. 1 - 6 .

[0018] Referring to FIGS. 1 and 2 , the detergent dispenser 100 includes a housing 101 having a front side 102 , a back side 103 , a top 115 , and a bottom 119 . The back side 103 faces the wall or the mounting surface and the front side 102 faces outward from the wall or the mounting surface. The front side 102 and the back side 103 converge to form a right side 111 and a left side 112 . The orientation of the right side 111 and the left side 112 of the dispenser 100 is determined by viewing the front side 102 of the dispenser 100 looking toward the wall or the mounting surface. The bottom encloses the front side 102 and the back side 103 while the top 115 provides an opening 117 , which allows access into a cavity 118 formed by the housing 101 . A hinge 116 is located proximate the back side 103 and the top 115 of the dispenser for connecting a lid 121 thereto. The lid 121 provides a cover for the opening 117 and the cavity 118 .

[0019] The cavity 118 is configured and arranged to receive a solid detergent block 125 and water from a fresh water source 127 . The solid detergent block 125 rests upon a false bottom 120 proximate the bottom 119 of the dispenser. The false bottom 120 is a mesh or screen member that extends across the cavity 118 to position the detergent 125 above the water supply but allows water to pass through to dissolve the detergent 125 . The false bottom 120 ensures that the detergent 125 dissolves evenly because the bottom 126 of the detergent 125 is not always in contact with water remaining at the bottom 119 of the dispenser 100 .

[0020] As shown in FIG. 5, a mounting member 104 is operatively connected to the back side 103 of the dispenser 100 . The mounting member 104 includes flanges with apertures 104 a proximate the right side 111 and the left side 112 through which screws or other means for securing the dispenser 100 to a wall or an attachment surface are placed. The mounting member 104 also includes an aperture 105 proximate the top 115 and the right side 111 of the dispenser 100 through which tubing 130 from a rinse water source 127 is placed to supply the dispenser 100 with fresh water. A valve support member 106 proximate the center of the dispenser 100 below the aperture 105 is also included to support a ¼ inch valve 122 . The valve support member 106 provides a compartment in which the valve 122 is placed and also includes an aperture 108 near the right side 111 of the dispenser for adjusting the valve 122 . Proximate the bottom of the valve support member 106 is an aperture 107 through which tubing 131 extends from the valve 122 to a water inlet 109 at the bottom 119 of the dispenser 100 . A water flow guide member 110 interconnects the tubing 131 to the water inlet 109 and ensures that the water fills from the bottom 119 of the dispenser. An optional vacuum breaker 139 in fluid communication with the tubing 130 ensures that excess water flowing into the water inlet 109 does not return to the water source 127 thereby contaminating the water source 127 . Alternately, an air gap could be provided rather than providing the vacuum breaker 139 . Providing either the vacuum breaker 139 or an air gap is mandated by the ASSE plumbing code for back flow prevention.

[0021] A use solution outlet 113 is located proximate the bottom 119 and the left side 112 of the dispenser. The use solution outlet 113 is configured and arranged to allow substantially all of the water and the use solution to flow out of the cavity 118 and into the dishwashing machine 132 . When substantially all of the water and the use solution flow out of cavity 118 , substantially all means that enough of the water and the use solution are dispensed so that the water and the use solution are not in contact with solid detergent 125 . The diameter of the use solution outlet 113 is approximately {fraction (3/16)} to {fraction ( 1 / 2 )} inch. Although it is unlikely that portions of solid detergent 125 would flow out of the cavity 118 along with the use solution, it is possible, especially if solid detergent pellets rather than a block and an overflow outlet 114 is used. The overflow outlet 114 is a {fraction (3/16)} inch aperture proximate the top 115 of the dispenser 100 . The overflow outlet 114 allows excess water inside cavity 118 to readily escape in the event too much water flows into the cavity 118 rather than having the excess water or use solution spill out from the top 115 of the dispenser 100 . Therefore, a screen or sieve type member known in the art may be placed over the outlets 113 and 114 to prevent solid detergent 125 from flowing out of the dispenser 100 . The use solution outlet 113 and the overflow outlet 114 converge proximate the bottom 119 of the dispenser 100 to form an outlet 145 . Therefore, the outlet conduit 123 is in fluid communication with both the use solution outlet 113 and the overflow outlet 114 to allow the water and the use solution to flow into the dishwashing machine 132 .

[0022] Use solution outlet 113 is always open and substantially all of the use solution in the cavity 118 is dispensed through the use solution outlet 113 . Therefore, no water remains in contact with the bottom of the detergent 125 when no water is flowing into the cavity 113 and the dispenser 100 is not in use. In order for the dispenser 100 to work properly, the rate of flow of water into the cavity 118 should be greater than the rate of flow of the use solution out of the use solution outlet 113 for a time sufficient to flood the cavity 118 and create the use solution. In the preferred embodiment, the rate of water flowing into the dispenser is approximately 0.5 to 1.0 gallons per minute, and the rate of use solution flowing out of the dispenser is approximately 0.1 to 0.2 gallons per minute. Also, the preferred range of the detergent 125 concentration in the use solution is 1.0 to 2.0% weight to weight. The rate of water flowing into the cavity 118 depends on several factors including the diameter and length of tubing 130 , the amount of pressure in the water supply, and the valve 122 setting. The valve 122 may be adjusted to ensure that the desired volume of the use solution is dispensed from the dispenser 100 . The maximum outflow of water and use solution from the use solution outlet 113 is approximately 0.5 gallons per minute.

[0023] An outlet conduit 123 utilizes gravity to allow the use solution to flow from the outlet 145 into the use solution inlet 138 of the dishwashing machine 132 . This is shown in FIG. 6 . The preferred embodiment utilizes a ⅝ inch Mayon Hose (PVC) to carry the use solution to the dishmachine wash water storage tank 135 . The outlet conduit 123 is in fluid communication with the use solution outlet 113 and the overflow outlet 114 of the dispenser 100 , and the outlet conduit 123 is also in fluid communication with the use solution inlet 138 of the dishwashing machine 132 . Therefore, the outlet conduit 123 and the use solution inlet 138 allow the use solution to enter the wash water storage tank 135 in the dishwashing machine 132 .

[0024] The dishwashing machine 132 is a re-circulating machine, which reuses the water used during the wash and rinse cycles in the wash cycle and uses fresh water each time in the rinse cycle. Therefore, as the wash water is diluted during each rinse water, more detergent must be added to return the detergent concentration to the desired level to effectively clean and sanitize the dishes. The dishwashing machine 132 receives water from a water line 128 , which is preferably a ¾ inch line receiving water from a fresh water source 127 . A port 129 having a threaded plug diverts some of the water from the dishwashing machine 132 via water inlet tubing 130 to the dispenser 100 . Two ⅛ to ⅞ inch ports are typically available on a dishwashing machine, and the water inlet tubing 130 is preferably a ¼ to ⅜ inch copper tubing. However, other means well known in the art may be used to divert the water to the dispenser 100 . During the rinse cycle, the back pressure of the water flowing into the rinse arms 133 causes the rinse arms 133 to rotate and also causes water to flow through the port 129 and into the water inlet tubing 130 . A check valve 142 in the water inlet tubing 130 prevents back flow of water to the dishwashing machine 132 . An optional vacuum breaker 139 may be included if the dispenser 100 is mounted above the dishmachine vacuum breaker 140 . The dishmachine vacuum breaker 140 is an atmospheric vacuum breaker located approximately 6 inches higher than the dishwashing machine 132 to prevent back flow of water to the fresh water source 127 .

[0025] During the rinse cycle of the dishwashing machine 132 , rinse arms 133 receive water from the water line 128 . During the wash cycle of the dishwashing machine 132 , sump 136 pumps wash water from a wash water storage tank 135 into wash arms 134 . The wash water storage tank 135 also includes an overflow wash water outlet 137 that allows excess wash water to exit the storage tank 135 rather than overflow the dishwashing machine 132 . The excess wash water and rinse water exits the dishwashing machine 132 to the drain through tubing 144 . The preferred embodiment dispenser 100 is used with a 15 to 16 gallon 14AM Hobart dishwashing machine, but the dispenser 100 may be used with any type of re-circulating dishwashing machine.

[0026] In another embodiment of the present invention, rather than supplying water to the bottom 119 of the dispenser 100 , water may be supplied to the top 115 of the dispenser 100 . Therefore, the water inlet 109 may be placed at either the bottom 119 or the top 115 of the dispenser 100 . Although water may be sprayed onto the detergent 125 or otherwise allowed to contact the detergent 125 , this tends to erode the detergent 125 unevenly. Therefore, it is preferred to flood the dispenser 100 from the bottom 119 . To ensure that water does not unevenly erode the detergent 125 , the water flow guide member 110 is positioned proximate the water inlet 109 to guide the water to the bottom 119 of the dispenser 100 . This feature is disclosed in U.S. patent application Ser. No. 09/550,428, filed Apr. 17, 2000, which is herein incorporated by reference.

[0027] In operation, as shown in FIG. 6 , water from the fresh water source 127 flows into the water line 128 during the rinse cycle of the dishwashing machine 132 . The water has a temperature of approximately 180° F. or higher and flows at a pressure of approximately 20 psi. The fresh water flows from the water line 128 into the rinse arms 133 of the dishwashing machine 132 . Because of the back pressure of the water, water also flows into the port 129 that directs the fresh water into the water inlet tubing 130 to the dispenser 100 . The water flows simultaneously into the rinse arms 133 and into the dispenser 100 via the water inlet tubing 130 . Simultaneously means that water is flowing concurrently into the rinse arms 133 and the dispenser 100 at some time during the rinse cycle. The water could start or stop in one or the other during the rinse cycle, but water is supplied at some point of the rinse cycle to both at the same time. The water from the rinse arms 133 cascades into the wash water storage tank 135 .

[0028] At the start of each day, the wash water storage tank 135 is empty so the cycle begins with an extended rinse cycle to sufficiently fill the tank 135 with fresh water. Depending upon the type of dishwashing machine used, approximately 10 to 100 or even greater gallons of fresh water fill the tank 135 . This fresh water does not contain any detergent, but the tank 135 receives use solution containing detergent from the dispenser simultaneously. During subsequent rinse cycles, the wash water containing detergent use solution becomes diluted with approximately 1.5 gallons of fresh rinse water, and the amount of fresh rinse water displaces a proportional amount of wash water, which exits through an overflow wash water outlet. A solenoid 141 connected to the control center (not shown) of the dishwashing machine 132 triggers the rinse cycle to begin, and every time fresh water flows through the dishmachine valve 143 , fresh water also fills the dispenser 100 to provide use solution to the wash water storage tank 135 .

[0029] From the port 129 , the water flows through the check valve 142 and into the water inlet tubing 130 . The check valve 142 ensures that water from the dispenser 100 does not flow into the dishwashing machine 132 . If the dispenser 100 is mounted above the dishmachine vacuum breaker 140 , an optional vacuum breaker 139 may be included to provide additional assurance that water from the dispenser 100 does not flow into the dishwashing machine 132 . Also, an optional restrictor may be provided to reduce the pressure and the flow of the water flowing into the dispenser 100 . The water flows through water inlet tubing 130 into valve 122 . The valve 122 regulates the amount of water flowing into the tubing 131 and the water inlet 109 via water flow guide member 110 . As the water enters the water inlet 109 , it floods the cavity 118 from the bottom. The water level rises above the false bottom 120 and contacts the detergent 125 , and a portion of the detergent 125 dissolves into the water thereby creating a use solution. The use solution exits the cavity 118 through the use solution outlet 113 by way of a gravity drain. Although the use solution outlet 113 is always open, water floods the cavity 118 at a faster rate than the use solution exits the use solution outlet 113 . It takes approximately 2 to 3 minutes for the water to fill the cavity 118 to approximately the water level L, as shown in FIGS. 3 and 4 . Therefore an adequate amount of detergent 125 is able to dissolve in the water during the time allowed for the rinse cycle.

[0030] The use solution flows from the use solution outlet 113 into the outlet 145 . However, if the cavity 118 becomes flooded with use solution, excess use solution will exit the dispenser 100 through the overflow outlet 114 , in which case the use solution will also flow into the outlet 145 . In either instance, the use solution will flow from the outlet 145 into the use solution inlet 138 of the wash water storage tank 135 via outlet conduit 123 . As the use solution enters the storage tank 135 , excess wash water in a proportional amount equal to the amount of use solution entering the storage tank 135 flows out of the storage tank 135 via the overflow wash water outlet (not shown). Therefore, the use solution replenishes the wash water that has become diluted during the rinse cycle with additional detergent as it displaces a proportional amount of diluted wash water equal to the amount of use solution entering the storage tank 135 .

[0031] After the rinse cycle has finished and it is time for the next wash cycle to begin, the sump 136 pumps the replenished wash water into the wash arms 134 . The wash water from the wash arms 134 cascades back into the wash water storage tank 135 where it again becomes diluted with fresh water from the rinse arms 133 during the subsequent rinse cycle. However, the wash water simultaneously becomes replenished with use solution during the rinse cycle, as described above. This cycling of diluting and replenishing continues for each full wash and rinse cycle. At the end of the day or after the wash water becomes heavily soiled, the wash water storage tank 135 is emptied and must be refilled as at the start of the day described previously.

[0032] In the preferred embodiment, water floods the cavity 118 from the bottom 119 of the dispenser 100 and the water level increases as water flows into the cavity 118 from the water inlet 109 . Because of the false bottom 120 , water floods the cavity 118 beneath the detergent 125 and then rises above the false bottom 120 to contact the detergent 125 . Filling cavity 118 from the bottom minimizes the vortices and the eddies, which tend to erode detergents unevenly. Less impingement occurs when the cavity 118 is filled from the bottom, and this allows for less detergent 125 to be dispensed than is typically dispensed in spray-type dispensers. In addition, this results in more uniform dissolution of the detergent 125 and a relatively constant concentration and shape of the detergent is maintained. Although it is recognized that cavity 118 may be flooded from the top 115 , more turbulence in the water will occur and the detergent will likely erode unevenly resulting in a variance in concentration and shape of the detergent as it dissolves. Uniform erosion of the detergent 125 is important because there is a linear relationship between the surface area of the detergent exposed to the water and the number of grams dispensed. Therefore, if the shape of the detergent 125 remains relatively constant, the surface area of the detergent will remain relatively constant and the exposure to water will keep the detergent dispensing rate relatively constant.

[0033] As cavity 118 is flooded with water from the bottom 119 of the dispenser 100 to a level L proximate the middle of the dispenser, the water contacts the detergent 125 and dissolves a portion of the detergent 125 to create a use solution. In the preferred embodiment, the cavity 118 is flooded approximately three to four inches above the false bottom 120 . Only a relatively small portion of the detergent 125 is dissolved each time water fills the cavity 118 and contacts the detergent 125 . The amount of water flowing into cavity 118 may be controlled by adjusting the valve 122 , which controls the amount of water flowing into the water inlet 109 . The water level L is important to ensure that the desired volume of use solution is dispensed into the dishwashing machine. Since different models of dishwashing machines may have different sump sizes, the machines may require different volumes of use solution, and the volume is controlled by allowing either more or less water into cavity 118 of the dispenser 100 . Again, the water inlet 109 is larger than the use solution outlet 113 to allow the detergent block 125 adequate time to dissolve into the use solution. No complicated mechanical or electrical devices are required to operate the dispenser 100 because the dispenser 100 works with the rinse cycle of the dishwashing machine 132 . All that is needed to control the amount of water entering the dispenser 100 , and therefore to control the volume of the use solution containing detergent 125 , is the valve 122 . However, other means known in the art may also be used such as a restrictor or other devices that control the flow of water.

[0034] The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.