US20090084330A1

US20090084330A1 - Enclosure for marine water heaters

Info

Publication number: US20090084330A1
Application number: US11/865,906
Authority: US
Inventors: John Mark Kloster; George P. Alliss
Original assignee: Atwood Mobile Products LLC
Current assignee: Atwood Mobile Products LLC
Priority date: 2007-10-02
Filing date: 2007-10-02
Publication date: 2009-04-02

Abstract

A water heater includes a rotationally molded plastic enclosure, and a tank for holding water to be heated located within the enclosure and having electrical components at a forward end. The enclosure has a cylindrically-shaped side wall, a front wall at a forward end of the side wall, and a rear wall at a rear end of the side wall to form an enclosed interior space for the tank. The front wall has an opening at the electrical components and a removable electrical enclosure is secured to the enclosure covers the opening in the front wall. The tank has a cold water inlet, a hot water outlet, a drain, and a relief valve and the enclosure has openings for the cold water inlet, the hot water outlet, the drain, and the relief valve. Preferably, a common molded enclosure blank is used for a plurality of different water heater configurations.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable

REFERENCE TO MICROFICHE APPENDIX

Not Applicable

FIELD OF THE INVENTION

The present invention generally relates to water heaters and, more particularly, to water heaters for marine applications.

BACKGROUND OF THE INVENTION

Water heaters for marine applications currently have painted metal-fabricated enclosures. These enclosures are particularly susceptible to damage during shipping and/or installation. Additionally there is an ongoing desire to reduce manufacturing costs and improve performance of these water heaters. Accordingly, there is a need in the art for an improved enclosure for marine water heaters.

SUMMARY OF THE INVENTION

The present invention provides an enclosure for a marine water heater which overcomes at least some of the above-noted problems of the related art. According to the present invention, a water heater comprises, in combination, a molded enclosure comprising a non-corrosive material, and a tank for holding water to be heated located within the enclosure and having electrical components at a forward end. The enclosure has a cylindrically-shaped side wall, a front wall at a forward end of the side wall, and a rear wall at a rear end of the side wall to form an enclosed interior space for the tank. The front wall has an opening at the electrical components.
According to another aspect of the present invention, a water heater comprises, in combination, a molded enclosure comprising a non-corrosive material and a tank for holding water to be heated located within the enclosure and having electrical components at a forward end. The enclosure has a cylindrically-shaped side wall, a front wall at a forward end of the side wall, and a rear wall at a rear end of the side wall to form an enclosed interior space for the tank. The tank has a cold water inlet, a hot water outlet, a drain, and a relief valve and the enclosure has openings for the cold water inlet, the hot water outlet, the drain, and the relief valve. The front wall has an opening at the electrical components and a removable electrical enclosure is secured to the enclosure covering the opening in the front wall. The electrical enclosure engages the tank to separate the electrical components from a space located between the enclosure and the tank.
According to yet another aspect of the present invention, a method of making water heater enclosures for a plurality of different water heater configurations comprises the steps of, in combination, molding identical first and second cylindrically-shaped enclosures, cutting the first enclosure in a direction perpendicular to a central longitudinal axis to form two portions having a first collective length for a first one of the water heater configurations, cutting openings in the first enclosure for the selected first one of the water heater configurations, cutting the second enclosure in a direction perpendicular to a central longitudinal axis to form two portions having a second collective length for a second one of the water heater configurations, and cutting openings in the second enclosure for the selected second one of the water heater configurations.
From the foregoing disclosure and the following more detailed description of various preferred embodiments it will be apparent to those skilled in the art that the present invention provides a significant advance in the technology and art of enclosures for marine water heaters. Particularly significant in this regard is the potential the invention affords for providing a high quality, reliable, efficient, and low cost assembly that is not easily damaged. Additional features and advantages of various preferred embodiments will be better understood in view of the detailed description provided below.

BRIEF DESCRIPTION OF THE DRAWINGS

These and further features of the present invention will be apparent with reference to the following description and drawings, wherein:

FIG. 1 is a front elevational view of a water heater according to the present invention;

FIG. 2 is a side elevational view of the water heater of FIG. 1;

FIG. 3 is a rear elevational view of the water heater of FIGS. 1 and 2;

FIG. 4 is a front perspective view of the water heater of FIGS. 1 to 3;

FIG. 5 is a rear perspective view of the water heater of FIGS. 1 to 4;

FIG. 6 is a side elevational view, in cross-section of the water heater of FIGS. 1 to 5;

FIG. 7 is front perspective view of an enclosure of the water heater of FIGS. 1 to 6 after rotational molding;

FIG. 8 is a rear perspective view of the enclosure of FIG. 7;

FIG. 9 is a side elevational view of the enclosure of FIGS. 7 and 8;

FIG. 10 a front perspective view of the enclosure of FIGS. 7 to 9 after cutting operations for a 6-gallon tank;

FIG. 11 is a rear perspective view of the enclosure of FIG. 10;

FIG. 12 a front perspective view of the enclosure of FIGS. 7 to 9 after cutting operations for a 4-gallon tank;

FIG. 13 is a rear perspective view of the enclosure of FIG. 12;

FIG. 14 a front perspective view of an electrical enclosure of the water heater of FIGS. 1 to 6;

FIG. 15 is a rear perspective view of the electrical enclosure of FIG. 14;

FIG. 16 a front perspective view of an alternative electrical enclosure of the water heater of FIGS. 1 to 6; and

FIG. 17 is a rear perspective view of the alternative electrical enclosure of FIG. 16.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of a water heater for a recreational vehicle as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. Certain features of the illustrated embodiments have been enlarged or distorted relative to others to facilitate visualization and clear understanding. In particular, thin features may be thickened, for example, for clarity or illustration. All references to direction and position, unless otherwise indicated, refer to the orientation of the water heater illustrated in the drawings. In general, up or upward refers to an upward direction within the plane of the paper in FIG. 1 and down or downward refers to a downward direction within the plane of the paper in FIG. 1. Also in general, fore or forward refers to a direction out of the plane of the paper in FIG. 1 and aft or rearward refers to a direction into the plane of the paper in FIG. 1.

DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS

It will be apparent to those skilled in the art, that is, to those who have knowledge or experience in this area of technology, that many uses and design variations are possible for the improved water heaters disclosed herein. The following detailed discussion of various alternative and preferred embodiments will illustrate the general principles of the invention with reference to a preferred embodiment of a water heater for a recreational vehicle. The term “recreational vehicle” as use in the specification and claims is intended to include all vehicles which are generally permanently installed at a site but are transported along a roadway a subsequent site such as mobile homes as well as vehicles that are readily moved along roadways among sites such as recreational vehicles (RVs), travel trailers, campers, and the like. Other embodiments suitable for other applications will be apparent to those skilled in the art given the benefit of this disclosure.
Referring now to the drawings, FIGS. 1 to 6 show a water heater 10 according to a preferred embodiment of the present invention. The illustrated water heater 10 includes a molded enclosure 12 comprising a non-corrosive material, a tank 14 for holding water to be heated located within the enclosure 12 and having electrical components 16 at a forward end, and an electrical enclosure 18 covering the electrical components 16.
The illustrated water tank 14 is generally cylindrically shaped having a horizontally disposed central axis 20. The illustrated tank 14 has a cylindrical-shaped side wall 22 closed by generally-planar forward and rearward walls 24, 26 to form a sealed hollow interior cavity for holding water to be heated. The illustrated tank 14 is fabricated of a suitable metal but it is noted that the tank 14 can alternatively be formed of any other suitable material.
The illustrated water tank 14 is provided with a cold water inlet 28 for connection to a source of water to be heated and a hot water outlet 30 for connection to hot water supply line for appliances which use directing hot water such as sinks, showers etc. The illustrated inlet and outlet 28, 30 forwardly extend from the water tank 14 through openings in the forward end wall 24. The illustrated water tank is also provided with a drain 32 for draining water from the tank 14. The illustrated drain 32 forwardly extends from the water tank 14 through an opening in the end wall 24. The illustrated water tank 14 is further provided with a pressure/temperature (P/T) relief valve 34 which relieves pressure within the tank 14 if the pressure within the tank 14 exceeds a predetermined limit. The illustrated relief valve 34 forwardly extends from the water tank 14 through an opening in the forward wall 24. The illustrated water tank 14 is moreover provided with motor assist inlet and outlets 36, 38 of an engine assisted heat exchanger 40 which extends within the tank 14 so that hot fluids of a marine vehicle motor can assist heating water within the tank 14 if desired. The illustrated inlet and outlet 36, 38 forwardly extend from the water tank 14 through openings in the forward wall 24.
The illustrated water tank 14 is also provided with an electric heating element 42 for heating water within the tank 14. The illustrated heating element 42 extends into the water tank 14 through an opening in the forward wall 24. A power and control system is provided for operation of the heating element 42 in a desired manner. All electrical components 16 f the illustrated water tank 14 are centrally located at the forward wall 24.
The illustrated enclosure 12 is generally cylindrically shaped having a horizontally disposed central axis 20. The illustrated enclosure 12 has a cylindrical-shaped side wall 44 closed by generally planar forward and rearward end walls 46, 48 to form a sealed hollow interior cavity for closely holding the water tank 14 therein. The illustrated enclosure 12 also has a rectangular shaped base 50 at its bottom. The illustrated enclosure 12 is rotationally molded of a non-corrosive material such as a plastic. The non-corrosive material is preferably a plastic such as, for example, a polyethylene which resists scratching and denting damage. It is noted that the enclosure 12 can alternatively be formed by any other suitable method and of any other suitable material.
The illustrated forward end wall 46 has an opening 52 for the cold water inlet 28, an opening 54 for the hot water outlet 30, an opening 56 for the drain 32, an opening 58 for the pressure/temperature (P/T) relief valve 34, an opening 60 for the motor assist inlet 36, and an opening 62 for the motor assist outlet 38. The illustrated cold water inlet 28, the hot water outlet 30, the drain 32, the pressure/temperature (P/T) relief valve 34, the motor assist inlet 36, and the motor assist outlet 38 each forwardly extend through the respective openings 52-62. The illustrated forward end wall 46 also has a centrally located opening 64 for providing access to the electrical components 16. The illustrated electrical components 16 each forwardly extend through the opening 64. The illustrated enclosure 12 further includes recessed areas 66 a, 68 a in the rearward end wall 48 which can be utilized to cut openings 66, 68 for other water heater configurations as described in more detail hereinafter.
Mounting brackets 70, 72 are provided at forward and rearward ends of the water tank 14. The illustrated mounting brackets 70, 72 have a vertical portion that downwardly extends from the water tank 14 within the enclosure 12 and a horizontal portion that outwardly extends from a lower end of the vertical portion through openings 74 in the enclosure 12. The horizontal portions are preferably provided with openings for mechanical fasteners for securing the water heater 10 to a support structure of the marine vehicle. The illustrated mounting brackets 70, 72 are secured to the tank 14 with mechanical fasteners 76 but any other suitable method can be utilized. The fasteners 76 securing the illustrated forward mounting bracket 70 also secure the heating element 42. The illustrated mounting brackets 70, 72 are formed of a metal so that the mounting brackets 70, 72 can be attached to a ground to ground the water tank 14 and the heating element 42.
The illustrated electrical enclosure 18 is sized and shaped to cover the electrical components 16 and cooperates with the tank 14 to enclose the electrical components 16. The electrical enclosure 18 is removably secured to the enclosure 12 so that the electrical components 16 can be accessed without removing the enclosure 12. The illustrated electrical enclosure 18 is removably secured with mechanical fasteners 78 but other means can be alternatively utilized. The illustrated electrical enclosure 18 is molded of a non-corrosive material such as a plastic. The non-corrosive material is preferably a plastic such as, for example, a polyethylene which resists scratching and denting damage. It is noted that the electrical enclosure 18 can alternatively be formed by any other suitable method and of any other suitable material.
As best shown in FIGS. 14 and 15, the illustrated electrical enclosure 18 has a main portion 80 which is generally box shaped having an open rear side. A flange 82 outwardly extends from the rear edge of the main portion 80 which is sized and shaped to engage the enclosure forward end wall 46 about the electrical component opening 64. The flange 82 is substantially planar to seat against the planar forward end wall 64 of the enclosure 12. The illustrated enclosure 12 is provided with a recessed seat for the electrical enclosure 18 (best shown in FIG. 10). The illustrated flange 82 is provided with openings 84 for the mechanical fasteners 78. It is noted that the electrical enclosure 18 can alternatively be secured to the enclosure 12 in any other suitable manner. For, example, FIGS. 16 and 17 illustrated an alternative electrical enclosure 18 a which is secured with a single mechanical fastener to the top of the flange 82 and a offset at the bottom of the flange 82.
The illustrated electrical enclosure 18 also includes a rearwardly extending top wall 88 and rearwardly extending side walls 88 which are sized and shaped to extend into the enclosure 12 and engage the forward end wall 24 of the water tank 14. The illustrated side walls 88 are concave to closely match the tank 14. The top and side walls 86, 88 along with the mounting bracket 70 fully close the gap between the enclosure 12 and the water tank 14 about the electrical component opening 64 to separate the electrical components 16 from a space located between the enclosure 12 and the tank 14.
Suitable thermal insulation material 90 is preferably provided in the space formed between the water tank 14 and the enclosure 12. The insulation material 90 can be expandable foam, fiber, or any other suitable insulation. It is noted that the illustrated electrical enclosure 18 and the mounting bracket 70 fully isolate the electrical components 16 from the insulation material 90.
FIGS. 7 to 9 illustrate an enclosure blank 12 a that has been molded but not yet cut. The illustrated enclosure blank 12 a is rotationally molded with a plurality of recessed areas 52 a-64 a in the outer surface of the forward end wall 46. The recessed areas 52- are sized, shaped, and located to match the opening 52 for the cold water inlet 28, the opening 54 for the hot water outlet 30, the opening 56 for the drain 32, the opening 58 for the pressure/temperature (P/T) relief valve 34, the opening 60 for the motor assist inlet 36, the opening 62 for the motor assist outlet 38, and the electrical component opening 64. The illustrated enclosure blank 12 a also includes recessed areas 66 a, 68 a in the rearward end wall 48 to match openings 66, 68 for a second water heater configuration having the motor assist inlet 36 and the motor assist outlet 38 in the rearward end wall 48 as described in more detail hereinafter. The length of the enclosure blank 12 a is preferably longer than the desired enclosure 12 as described in more detail hereinafter.
FIGS. 10 and 11 illustrate the enclosure blank 12 a after it has been cut and is ready for assembly with a water tank 14. The recessed areas 52 a-64 a in the forward end wall 46 have been cut or routed to form the opening 52 for the cold water inlet 28, the opening 54 for the hot water outlet 30, the opening 56 for the drain 32, the opening 58 for the pressure/temperature (P/T) relief valve 34, the opening 60 for the motor assist inlet 36, the opening 62 for the motor assist outlet 38, and the electrical component opening 64. However, the recessed areas 66 a, 68 a in the rearward end wall 48 have not been cut because they are not used with the first water heater configuration. The enclosure blank 12 a has also been cut in a direction perpendicular to the central longitudinal axis 20 to form separate forward and rearward portions. The illustrated enclosure blank 12 a had a band of material removed to obtain the desired length for the enclosure 12 for the first water heater configuration. The illustrated forward and rearward enclosure portions have different diameters so that once cut to length, the forward portion can be slid into the rearward portion upon assembly about the tank 12. The forward and rearward portions of the enclosure 12 can be secured together in any suitable manner such as, for example, mechanical fasteners or the like.
FIGS. 12 and 13 illustrate the enclosure blank after it has been cut for use and is ready for assembly with a water tank having a second configuration. The illustrated second configuration is a smaller water tank (four gallons rather than six gallons) having the motor assist inlets and outlets 36, 38 in the rearward end wall 26 rather than the forward end wall 24. It is noted that there can alternatively be any other differences between the configurations within the scope of the present invention. The recessed areas 52 a-58 a, 64 a in the forward end wall 46 have been cut or routed to form the opening 52 for the cold water inlet 28, the opening 54 for the hot water outlet 30, the opening 56 for the drain 32, the opening 58 for the pressure/temperature (P/T) relief valve 34, and the electrical component opening 64. Also the recessed areas 66 a, 68 a in the rearward end wall 48 have been cut or routed to form the opening 66 for the motor assist inlet 36, and the opening 68 for the motor assist outlet 38. However, the recessed areas 60 a, 62 a in the forward end wall 46 have not been cut because they are not used with the second water heater configuration. The enclosure blank 12 a has also been cut in a direction perpendicular to the central longitudinal axis 20 to form separate forward and rearward portions. The illustrated enclosure blank 12 a had a band of material removed to obtain the desired length for the enclosure for the second water heater configuration. As, best shown in FIG. 9, a longer band of material has been removed than for the first water heater configuration because the second water heater configuration has a shorter length.
FIGS. 18 to 21 show an enclosure blank 112 a according to a second embodiment of the present invention wherein the enclosure blank 112 a has been blow molded. The second embodiment illustrates that the enclosure 112 a can be molded using other methods and that the enclosure blank 112 a can be molded without recesses for locating and cutting the various openings. It is noted that because blow molding tooling can be removed laterally, the side wall of the enclosure 112 can be molded with a circumferentially extending recess 112. When cut at the rear end, the recess 114 forms a reduced diameter flange for insertion into the rear portion of the enclosure 112. FIGS. 22 to 26 show the enclosure 112 after cutting operations for the water tank 14 having the first configuration. FIG. 27 shows the rear of the enclosure 112 when cut for the water tank 14 having the second configuration.
It is apparent from the forgoing description that a single molded enclosure blank 12 a, and thus single mold tooling, can be used for a plurality of different water heater configurations. While the invention was illustrated with two water heater configurations, it should be appreciated that the principles of the invention can be used for more than two water heater configurations. It should also be appreciated that the water heater configurations can have other differences than those of the illustrated embodiments. It should be further appreciated that while the illustrated embodiments were six and four gallon water tanks, any other suitable size can be utilized such as, for example, ten and twenty gallon tanks. It is apparent from the forgoing description that the present invention provides an improved water heater that is less susceptible to damage during shipping and/or installation, has improved thermal insulation, has improved corrosion resistance, and has reduced manufacturing costs.
From the foregoing disclosure and detailed description of certain preferred embodiments, it is also apparent that various modifications, additions and other alternative embodiments are possible without departing from the true scope and spirit of the present invention. The embodiments discussed were chosen and described to provide the best illustration of the principles of the present invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the present invention as determined by the appended claims when interpreted in accordance with the benefit to which they are fairly, legally, and equitably entitled.

Claims

1. A water heater comprising, in combination:

a molded enclosure comprising a non-corrosive material;

a tank for holding water to be heated located within the enclosure and having electrical components at a forward end;

wherein the enclosure has a cylindrically-shaped side wall, a front wall at a forward end of the side wall, and a rear wall at a rear end of the side wall to form an enclosed interior space for the tank; and

wherein the front wall has an opening at the electrical components.

2. The water heater according to claim 1, further comprising a removable electrical closure covering the opening in the front wall.

3. The water heater according to claim 2, wherein the electrical enclosure engages the tank to separate the electrical components from a space located between the enclosure and the tank.

4. The water heater according to claim 3, wherein insulation is located in the space between the tank and the enclosure.

5. The water heater according to claim 1, wherein at least one bracket is secured to the tank and the at least one bracket extends through an opening in the enclosure.

6. The water heater according to claim 5, wherein the tank and brackets each comprise metal and the brackets are attachable to a ground.

7. The water heater according to claim 1, wherein the tank has a cold water inlet, a hot water outlet, a drain, and a relief valve and the enclosure has openings for the cold water inlet, the hot water outlet, the drain, and the relief valve.

8. The water heater according to claim 7, wherein the opening for the relief valve is sized and shaped for passing the relief valve through the opening and the relief valve extends through the opening in the enclosure.

9. The water heater according to claim 1, wherein an exterior surface of the enclosure has recesses for cutting additional openings.

10. A water heater comprising, in combination:

a molded enclosure comprising a non-corrosive material;

wherein the enclosure has a cylindrically-shaped side wall, a front wall at a forward end of the side wall, and a rear wall at a rear end of the side wall to form an enclosed interior space for the tank;

wherein the tank has a cold water inlet, a hot water outlet, a drain, and a relief valve and the enclosure has openings for the cold water inlet, the hot water outlet, the drain, and the relief valve;

wherein the front wall has an opening at the electrical components;

a removable electrical enclosure secured to the enclosure and covering the opening in the front wall; and

wherein the electrical enclosure engages the tank to separate the electrical components from a space located between the enclosure and the tank.

11. The water heater according to claim 10, wherein insulation is located in the space between the tank and the enclosure.

12. The water heater according to claim 10, wherein at least one bracket is secured to the tank and the at least one bracket extends through an opening in the enclosure.

13. The water heater according to claim 12, wherein the tank and brackets each comprise metal and the brackets are attachable to a ground.

14. The water heater according to claim 10, wherein the opening for the relief valve is sized and shaped for passing the relief valve through the opening and the relief valve extends through the opening in the enclosure.

15. The water heater according to claim 10, wherein an exterior surface of the enclosure has recesses for cutting additional openings.

16. A method of making water heater enclosures for a plurality of different water heater configurations, said method comprising the steps of, in combination:

molding identical first and second cylindrically-shaped enclosures;

cutting the first enclosure in a direction perpendicular to a central longitudinal axis to form two portions having a first collective length for a first one of the water heater configurations;

cutting openings in the first enclosure for the selected first one of the water heater configurations;

cutting the second enclosure in a direction perpendicular to a central longitudinal axis to form two portions having a second collective length for a second one of the water heater configurations; and

cutting openings in the second enclosure for the selected second one of the water heater configurations.

17. The method according to claim 16, wherein the openings for the selected first one of the water heater configurations are in different locations than the openings for the selected second one of the water heater configurations.

18. The method according to claim 16, wherein the first collective length is longer than the second collective length.

19. The method according to claim 16, wherein the step of molding the first and second enclosures includes the step of rotationally molding the enclosures using a non-corrosive material.

20. The method according to claim 16, wherein the step of molding the first and second enclosures includes the step of blow molding the enclosures using a non-corrosive material.