Holding Tank With Internally Reinforced Sidewalls and Liquid Dispenser Using Same

Abstract

The inward and outward deflection of sidewalls of a holding tank for liquids is reduced or eliminated by sidewall reinforcing stringers that extend between the sides and which are located inside the tank. The stringers, maintain the separation distance between the sidewalls to keep the sidewalls substantially parallel to each other.

What is claimed is: 
     
         1 . A liquid holding tank comprising:
 a first wall;   a second wall opposite the first wall, the first wall and the second wall being thin; and   a first stringer inside the liquid holding tank and extending between the first and second walls, the stringer configured to reduce deflection of the first and second holding tank walls.   
     
     
         2 . The liquid holding tank of  claim 1 , wherein the first and second walls are substantially planar, substantially vertical, substantially parallel to each other and wherein the stringer is formed integrally with both the first wall and second wall. 
     
     
         3 . The liquid holding tank of  claim 1 , wherein the stringer is attached to the first and second walls by at least one of: welding, an adhesive and a mechanical fastener. 
     
     
         4 . The liquid holding tank of  claim 2 , wherein the first stringer and sidewall are formed together and are seamless. 
     
     
         5 . The liquid holding tank of  claim 3 , wherein the first wall and the second wall have smooth outside surfaces. 
     
     
         6 . The liquid holding tank of  claim 4 , wherein the first stringer is hollow. 
     
     
         7 . The liquid holding tank of  claim 5 , further comprising a second stringer, the second stringer being similar to, and vertically separated from the first stringer. 
     
     
         8 . The liquid holding tank of  claim 5 , further comprising a second stringer, the second stringer being similar to, and horizontally separated from the first stringer. 
     
     
         9 . The liquid holding tank of  claim 6 , wherein the first and second walls have a geometric center and wherein the first and second stringers extend between the first and second walls at first and second stringer locations, the first and second stringer locations being equally spaced away from the geometric center. 
     
     
         10 . The liquid holding tank of  claim 7 , wherein the first and second walls have a geometric center and wherein the first and second stringers extend between the first and second walls at first and second stringer locations, the first and second stringer locations being equally spaced away from the geometric center. 
     
     
         11 . The liquid holding tank of  claim 1 , wherein the first stringer is comprised of first and second portions, each portion having an annulus shaped face, the first and second portions being joined to each other by the joining of the annulus-shaped faces. 
     
     
         12 . A liquid holding tank comprising:
 a first sidewall;   a second sidewall, the first sidewall and the second sidewall having a first sidewall thickness;   a first stringer formed integrally with the first and second sidewalls and extending between the first and second sidewalls inside the liquid holding tank, the stringer being a hollow tube having a tube sidewall, the tube sidewall having a thickness substantially equal to the first thickness.   
     
     
         13 . The liquid holding tank of  claim 11 , wherein the first and second sidewalls and the stringer are molded at the same time and wherein the hollow tube has a draft of between about two degrees and twenty degrees. 
     
     
         14 . The liquid holding tank of  claim 11 , wherein the first and second sidewalls have corresponding centroids and wherein the stringer is located at the centroids of the first and second sidewalls. 
     
     
         15 . The liquid holding tank of  claim 9 , wherein the stringer is configured to exchange heat between air inside the stringer and at least one of liquid and air inside the holding tank. 
     
     
         16 . The liquid holding tank of  claim 9 , wherein the first portion of a wall stiffener and the first holding tank wall are a unitary structure. 
     
     
         17 . An assembly of reinforced liquid holding tanks, the assembly comprising:
 first and second reinforced liquid holding tanks, each tank having first and second opposing side walls, the first and second liquid holding tanks being adjacent to each other such that the second side wall of the first liquid holding tank is adjacent to, the first side wall of the second tank;   each reinforced liquid holding tank being comprised of:
 a first holding tank wall; 
 a second holding tank wall substantially parallel to the first holding tank wall and laterally separated from the first holding tank wall by a first separation distance; and 
 a wall stiffener extending between and attached to both the first and second substantially vertical holding tank walls, the wall stiffener being configured to maintain the tank width separation distance, at least where the wall stiffener is attached to the first and second holding tank walls. 
   
     
     
         18 . The assembly of reinforced liquid holding tanks of  claim 16 , further comprising a third reinforced liquid holding tank having first and second opposing side walls, such that the first wall of the third tank is adjacent to and in contact with the second wall of the second tank. 
     
     
         19 . The assembly of reinforced liquid holding tanks of  claim 16 , wherein the wall stiffener in each tank is hollow and the stiffeners in each tank are aligned. 
     
     
         20 . A liquid dispenser comprising:
 a refrigerated cabinet having an interior width defined by a separation distance between first and second cabinet walls; and   first and second reinforced liquid holding tanks located between the first and second walls, each tank having first and second opposing side walls, the first and second liquid holding tanks being configured to be placed adjacent to each other and inside the refrigerated cabinet such that the second side wall of the first liquid holding tank is adjacent to, and in contact with, the first side wall of the second tank;   each reinforced liquid holding tank being comprised of:
 a first holding tank wall having a smooth exterior surface; 
 a second holding tank wall, which is configured to be substantially parallel to the first holding tank wall and, laterally separated from the first holding tank wall by a first separation distance and which also has a smooth exterior surface; and 
 a hollow wall stiffening tube extending integrally formed with the first and second holding tank walls and extending between them, the hollow wall stiffening tube being configured to maintain a separation distance of the walls, at least where the wall stiffener is attached to the first and second holding tank walls, at least when a liquid is inside the holding tank. 
   
     
     
         21 . The liquid dispenser of  claim 20 , wherein a first hollow wall stiffening tube in the first tank is aligned with a second hollow wall stiffening tube in the second tank, the aligned wall stiffening tubes configured to allow air to flow between the first and second cabinet walls and configured to enable the first and second liquid holding tanks to move vertically relative to each other when the tanks are holding liquid.