RING DAM AND METHOD FOR MANUFACTURING A RING DAM

Abstract

A ring dam, fitting between a fluid container and a housing for the fluid container, may include an extruded Polyethylene (EPE) foam having an Ethylene-Vinyl Acetate (EVA) additive.

Claims

1. A ring dam, fitting between a fluid container and a housing for the fluid container, comprising: an extruded Polyethylene (EPE) foam having an Ethylene-Vinyl Acetate (EVA) additive.

2. The ring dam of claim 1 wherein the EPE foam comprises a first end and a second end and wherein the first end and the second end are heat welded together to form a continuous ring.

3. The ring dam of claim 1 wherein the EPE foam comprises a central void.

4. The ring dam of Claim of claim 1 wherein the ring dam has a torus shape.

5. The ring dam of claim 1 wherein the central void has a torus shape.

6. A method of manufacturing a ring dam, fitting between a fluid container and a housing for the fluid container, comprising the steps of: extruding Polyethylene (EPE) foam having an Ethylene-Vinyl Acetate (EVA) additive through a die; allowing the EPE foam to cure; cutting the EPE foam into a predetermined length, wherein the EPE foam has a first end and a second end; and heat welding the first end and the second end together to form a continuous ring.

7. The method of manufacturing a ring dam according to claim 6 wherein the predetermined length is no longer than the circumference or perimeter of the fluid container.

8. The method of manufacturing a ring dam according to claim 6 wherein the die is configured to impart a central void in the ring dam.

9. The method of manufacturing a ring dam according to claim 6 wherein the die is configured to impart a lateral cross-section in the ring dam having a furthest extent which is larger than a shortest distance between the fluid container and the housing.

10. The method of manufacturing a ring dam according to claim 9 wherein the furthest extent is in the range of 5 percent to 20 percent larger than the shortest distance.

11. The method of manufacturing a ring dam according to claim 6 wherein the die is configured to impart a circular shape to a lateral cross-section in the ring dam such that the ring dam has a cylindrical shape prior to the heat welding step and has a torus shape after the heat welding step.

12. The method of manufacturing a ring dam according to claim 6 wherein the heat welding step utilizes a heat fin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Features, aspects and advantages of the present invention are understood when the following detailed description of the invention is read with reference to the accompanying drawings, in which:

[0023] FIG. 1 is side end view of the invention;

[0024] FIG. 2 is a perspective view of the invention;

[0025] FIG. 3 is a cutaway environmental view of the ring dam installed in a water heater;

[0026] FIG. 4 is an opposite side end view of the invention;

[0027] FIG. 5 is a perspective view of the invention before it has been heat welded;

[0028] FIG. 6 is a top view of the invention after it has been heat welded;

[0029] FIG. 7A is a side end view of an embodiment of the invention with cog shaped profile

[0030] FIG. 7B is an opposite side end view of the invention; and

[0031] FIG. 8 is a partial side cutaway view of an embodiment of the invention with a cog shaped profile installed between a tank and a shell or housing.

DETAILED DESCRIPTION OF THE INVENTION

[0032] The present invention will now be described more fully hereinafter with reference to the accompanying drawings in which exemplary embodiments of the invention are shown. However, the invention may be embodied in many different forms and should not be construed as limited to the representative embodiments set forth herein. The exemplary embodiments are provided so that this disclosure will be both thorough and complete, and will fully convey the scope of the invention and enable one of ordinary skill in the art to make, use and practice the invention. Like reference numbers refer to like elements throughout the various drawings.

[0033] Referring to the figures, a ring dam 10 is shown. The ring dam 10 is a type of seal which fits between a fluid tank 20, such as a hot water heater tank, and an outer housing 30, such as the jacket for a hot water heater. The ring dam 10 may be used in many different applications. In particular, one such application, as shown in FIG. 3, is a fired appliance such as a natural gas or liquid petroleum gas hot water heater tank.

[0034] The ring dam 10 is put into place around the tank 20 and between the tank 20 and the jacket 30 by an installer who may use a tamper tool (not shown) to tamp the ring dam 10 down from the top of the tank 20 until the ring dam 10 reaches a predetermined distance from the top of the tank 20. As the ring dam 10 is tamped into place by the installer, it rolls and moves down the length of the tank 20. The tamper may have a length which equates to the predetermined distance from the top of the tank 20. When fully tamped and installed, the ring dam 10 forms a seal at a lower portion of the tank 20 so that expanding foam may be installed in the void between the tank 20 and the housing and above the ring dam 10. The ring dam 10 protects expanding foam insulation from encroaching the hot water heater burner 40 and the area.

[0035] The ring dam 10 of the present invention is made from an extruded Polyethylene (EPE) foam having an Ethylene-Vinyl Acetate (EVA) additive. As shown in FIGS. 1-5, the ring dam 10 may have a circular cross section after being extruded and prior to installation. The ring dam 10 may also have a central void 12 as shown in FIGS. 1-5. The central void 12 may also have a circular cross section after being extruded and prior to installation. The ring dam 10 and the central void 12 may have other cross section shapes including the shapes shown in FIGS. 7-8.

[0036] The Polyethylene (EPE) foam having an Ethylene-Vinyl Acetate (EVA) additive is extruded through a die imparting the cross section shape and central void 12 as discussed above. The die also imparts a cross section diameter to the ring dam 10. The diameter of the cross section of the ring dam 10 corresponds to a particular application. That is, a smaller distance between the tank 20 and the jacket 30 would generally equate to a smaller cross section diameter of the ring dam 10. Likewise a larger distance between the tank 20 and the jacket 30 would generally equate to a larger cross section diameter of the ring dam 10. According to one embodiment, the diameter of the cross section of the ring dam 10 at a furthest extent is in the range of 5 percent to 20 percent larger than the shortest distance between the tank 20 and the jacket 30.

[0037] As the foam is extruded, the foam forms an elongate rod shape such as shown in FIGS. 2 and 5. The foam is allowed to cure. Once cured, the foam is cut into predetermined lengths. The predetermined length corresponds to the circumference or perimeter of the tank 20.

[0038] As part of the cutting process, a first end, FIG. 1, and a second end, FIG. 4, of the ring dam 10 are formed. The first and second ends are then heat welded 14 together to form a ring shape. The EVA additive may help strengthen the heat weld 14. For embodiments where there is a circular cross section, the ring dam will have a substantially torus shape.

[0039] A ring dam 10 according to the invention has been described with reference to specific embodiments and examples. Various details of the invention may be changed without departing from the scope of the invention. Furthermore, the foregoing description of the preferred embodiments of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation, the invention being defined by the claims. It is envisioned that other embodiments may perform similar functions and/or achieve similar results. Any and all such equivalent embodiments and examples are within the scope of the present invention and are intended to be covered by the appended claims.