US 3735895 A
A water tank in which an inner cylindrical vessel, of molded plastic wound with reinforcing strands has a base affixed to its lower end and is enclosed in an outer, cylindrical shell which seats in an upper edge of the base. The shell is reflective externally and air space is provided interiorly, so that the tank does not sweat.
Claims available in
Description (OCR text may contain errors)
lJnited States Patent 1191 1111 3,73,95 0 er 1 Ma 29 1973 [5 COMPOSITE NON-SWEAT WATER 3,557,827 1/1971 Marsh ..22o/3 TANK 299,673 6/1884 OHara ..220/69 3,159,306 12 1964 L all ..220 63 R  Inventor: Jarold D. Roper, 17125 Bixby, Bell- I y l flower Cahf' 90706 Primary Examiner--Samuel B. Rothberg  Filed: May 24, 1971 Assistant Examiner-Stephen Marcus 1 pp No 146 050 Attorney-Newton H. Lee, Jr.
'  ABSTRACT if A water tank in which an inner cylindrical vessel, of d /5 A 9 LG molded plastic wound with reinforcing strands has a l 1 e 0 2 87 70 5 R base affixed to its lower end and is enclosed in an outer, cylindrical shell which seats in an upper edge of the base, The shell is reflective externally and air  References Cited space is provided interiorly, so that the tank does not UNITED STATES PATENTS Sweat- 3,0s1,9o5 3/1963 Schulze et al. ..220/66 1 Claim, 3 Drawing Figures PATENTEB HAYZ 9 I973 INVENTOR IMROLBQ ROPER BACKGROUND OF THE INVENTION Water tanks containing cold water have historically posed problems in respect of the tendency of the tank to sweat, or accumulate water of condensation when located in a humid environment, on the one hand, and the inability to maintain the water cool when located out-of-doors and exposed to the sun. An example of such a tank is the usual water tank forming part of a domestic water purifying or softening system, such as the system employed in many parts of the country having varying weather conditions.
While certain plastic vessels, particularly of the double wall type are useful in humid areas and are not adversely affected by sweating or condensation due to the relatively cold water contained therein, such tanks do not stand continued exposure to the sun when placed out-of-doors. Such tanks moreover are incapable of preventing the water temperature from being undesirably elevated to the point that excessive water must transfer through the system to reduce the temperature to a satisfactory level at an outlet.
SUMMARY OF THE INVENTION The present invention provides a composite tank structure which obviates the condensation and heat problems of the prior art water tanks of the type used in water treating systems, while at the same time providing a tank which is of pleasing appearance, long life, and thusinexpensive.
More particularly, the invention provides a composite water tank assembly for water treating systems and the like, wherein a plastic, double walled inner tank and an outer tank are combined, whereby the heat reflective and weather resistant characteristics of the outer tank are availed of without experiecing the sweating or condensation forming characteristics of the usual tanks.
in accomplishing the foregoing, a cylindrical inner tank is provided with a base on which the tank assembly is supported in an upright position, and the outer tank fits telescopically over the inner tank and sealingly engages the base and the top of the inner tank to provide a dead air space between the inner and outer tanks. Such a tank assembly may be placed, in use, in a humid environment without sweating or forming condensation on the exterior of the outer tank, and, preferably, the outer tank is reflective so as to enable the use of the tank assembly, as well, in locations in which it is subjected to sunlight and heat, without experiencing either deterioration, as is common in plastic tanks, or significant elevation of the temperature of the water in the inner tank.
This invention possesses many other advantages, and has other purposes which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.
i ON OF DWWGS FIG. 1 is a side elevation of a composite, nomsweat water tank made in accordance with the invention;
FIG. 2 is an enlarged view in vertical section and with parts broken sway to expose the interior of the tank; and
FIG. 3 is a horizontal section as taken on the line 3-3 of FIG. 2.
DESCON OF THE PREFEE' EWODTMENT As seen in the drawing, the invention comprises a cylindrical tank assembly T adapted to be disposed in an upright position on a base 10 and having a fitting 11 at its upper end to which the usual valves and the like (not shown) are connectable, so that the tank is adapted to be used, say, in a water treating, purifying or softening system, as is well known. The illustrated tank assembly T is of elongated cylindrical form, in the sense that it is substantially longer axially than the diametrical dimension, but various sizes and dimensional relationships may be employed.
]Referring to FIG. 2, it will be seen that the tank T is a composite of an inner cylindrical tank or receptacle l2 and an outer cylindrical cover tank 13.
The inner tank or receptacle 12 is adapted to contain the water and, for example, resin water purifying beads, and consists of inner plastic shell 14 and an outer reinforced plastic shell 115. The inner tank shell 14 has a bottom plug 117 and is integral with the top fitting 111 at the outer periphery of the top fitting. This fitting 11 has a suitable threaded opening llh adapted to receive the valve connections as referred to above. The inner shell Ml, the fitting 111 and plug 117 may be composed of suitable plastic, such as ABS (Acrylonitrile-Butadiene- Styrene) or other thermoplastic material, facilitating blow molding of the shell 1 The outer shell 15 is preferably composed of windings of glass fibers or filaments and a binder of polyester resin. Aflixed to the bottom of the tank 112 is the base or support Ml comprising a base ring 21 having at its upper end an inwardly and downwardly extending flange 22 which is arched to conform to the shape of the bottom of the inner tank 12. Preferably adhesive is employed to secure the base it) to the tank 12. At its upper edge, the base ring 211 is provided with an upwardly opening annular grove 23.
Such an inner tank construction has the characteristic of sweating when placed in a humid environment, and the polyester resin reinforced outer shell 15 has the characteristic that it is damaged by exposure to sun light over a long period of time.
Accordingly, the outer tank 113 is telescoped over the upper end of the inner tank 112, with the lower end of the outer tank seating in the groove 23 in the upper edge of the base ring 21. The top 24 of the outer tank 13 has a central opening 25 in which the fitting 11 fits. While the outer tank may tightly fit the inner tank, such air space as exists will be a dead air space, further insulating the inner tank from the exterior humidity and temperature. The outer tank may be suitable metal or plastic construction which is preferably of reflective material, such as stainless steel or a reflective coating is employed preferably, so as to reflect the heat from the sun and assist in keeping the water in the inner tank 12 at a useful temperature during hot sunny weather.
From the foregoing, it is apparent that the invention provides a composite tank assembly in which the heat reflective and weather resistant qualities of an outer metal or other resistant material tank are combined with the superior characteristics of the plastic inner tank so that the tank assembly does not sweat or collect moisture of condensation when the tank is located in a humid area, and the plastic inner tank is protected from the deleterious effect of the sun when the tank is located in an area exposed to the sun. In addition, the water in the tank will be maintained more nearly at a useful temperature.
1. A composite water tank for use in water purifying and softening systems, comprising: an inner self- 4 supporting tank of plastic material, a fitting on top of said inner tank for connecting the inner tank in the water system, a base on the bottom of said inner tank forming a support, and an outer tank covering said inner tank engaged with said base and with the top of said inner tank, said outer tank having an opening in which said fitting is disposed, said inner tank comprising an inner molded plastic shell and an outer shell of filament reinforced plastic including glass fiber windings on said inner shell and a resin binder, said base being afiixed to the bottom of said inner tank and having an upwardly opening groove receiving the lower end of said outer tank, and said outer tank having a reflective exterior surface.