Title of Invention

"MOLDED MOUNTING DISC UNIT FOR A DOMESTIC WATER HEATER"

Abstract

The present invention provides a molded mounting disc unit of a domestic water heater system which is made up of a thermoplastic material using injection molding technique. The main advantage of this mounting disc unit is that it is free from any welding, corrosion, or coating with nickel, chrome etc. Such a molded mounting disc unit when used in a domestic water heater system, results in faster production and also improves the thermal insulation of the water heater. The molded mounting disc unit of the present invention is depicted in Fig. 4A of the specification and is shown below.

Full Text

Field of invention The present invention in general, relates to a mounting disc unit for a domestic water heater system, and in particular, relates to a molded mounting disc unit for a domestic water heater. Background The water heater is a domestic appliance, which is used to heat up the water for bathing and kitchen purposes. It generally comprises of an outer housing, an inner water storage tank and a unit assembly which controls the flow of the water wherein, the said unit assembly provides housing for the Heating element, thermostats, water ports and different valves. The said water heater optionally comprises a pressure reducing valve capable of reducing the inlet water pressure from high pressure for protecting the tank. US patent 6266484 relates to a complete water heater with outer and inner shells made of plastic materials. This invention just describes about two welded plastic shells - one covering the other for thermal insulation. US patent 5668922 deals with high capacity storage water heaters with extendable and flexible capacity. US patent 5923819 is quite similar to the one referred in US Patent 5668922 and the product design is similar to that. Here the patent claim is for fluid storage tank and not as water heater as in above patent. US patent 6184509 is about the system of fixing a permanent, non repairable but a leak proof mounting of a heating element on a plastic vessel. Applicant had also filed two Indian patent applications titled "pressure protection valve" Application No: 1172/DEL/2004 dated 23.06.2004 and second application titled "Domestic Water Heater" Application No.1172/DEL/2004 dated 23.06.2004. Outer Housing The Outer Housing is basically a shell which covers the water storage tank and rest of the components. Only Inlet and Outlet water ports and the wire cord for electrical connections corne out of this shell. The outer casing also helps in covering the thermal insulation material provided all around the water storage tank. This thermal insulation material is used to keep the heated water warm for a long period of time. The outer housing is made in various options to suit the aesthetic taste of the customer. The most conventional option is metal housing. In this case a mild steel sheet is rolled to form a tubular center section and its lateral ends are joined by spot welding or riveting. The top and bottom of this tubular section is covered with two end covers made out of deep drawn mild steel sheet only. The top cover is a closed end cover. The bottom end cover carries an opening for water pipes and wire cord. Whole of this unit is finished either by some stoving paint or powder paint. The joining edges of center tubular section and end covers are normally covered with a PVC belt to hide the fastening screws. In an alternate option the end covers are made out of ABS plastic. The advantage of using ABS plastic here is that it makes the end covers electrical shock proof and rust proof. The third option used by many manufacturers is to make full outer shell out of some thermoplastic material. In case of full plastic outer shell, it is made in two parts only -the back side and the front side. The advantage of making full plastic outer housing is that it makes the whole of the unit rust proof and electrical shock proof. The plastic variant further offers a wide variety of design options and a high gloss finish to the product. All the outer housing then carry a set of mounting clamps. The mounting clamps are used to hang the water heater on the wall. Water storage tank Every water heater carries a water storage tank. The water to be heated is stored in this tank. There are a number of materials that are used for this storage tank - Copper, Stainless Steel, Galvanized mild steel, vitreous enameled mild steel etc. The only purpose of this tank is to store the water. Prior to heating, during heating and after heating as well - a certain level of water is always maintained in this tank. Every tank carries a mouth opening ranging from 2 inches to 6 inches diameter. This mouth opening needs to be sealed in every water heater to make it water tight. Then the water heater also needs provisions for inflow of cold water, outflow of heated water, provision of heating, provision for heat controlling, provision for pressure controlling etc. All these objects are achieved through a Unit assembly. Conventional Unit Assembly The unit assembly is basically a brass plate, which is used to close the mouth of the tank. The inlet water pipe and outlet water pipe are also made out of brass and are welded to the brass plate. On the other side of these pipes -either copper or Brass pipe are welded to maintain the water level inside the tank and to provide a good mixing of cold water coming in. This plate also carries a mounting place for the heating element and thermostats. In addition, fuse plugs, drain nuts, and pressure release valves etc are also mounted on this unit plate. Whole of this unit is made out of either brass or copper parts. Immaterial of the material of the tank, this brass plate with other components attached to this brass plate is called unit assembly which is more or less same in all the cases. The conventional brass plate is shown in figure 1. The water heaters are available in various storage capacities and mounting options. Capacity for example may range from 1 liter to 100 liters. In the mounting options, for example Vertical, Horizontal and Floor model are the different options. For each capacity and model, the tank and unit assembly design varies. Every water tank carries an opening of about 5 to 6 inches. This unit assembly plate is mounted on this opening of the tank. The said unit assembly seals the water tank to make it watertight and provides for the connection of input and output ports for the water. The heating element and thermostats are also mounted on this assembly. Additionally this assembly carries a controlled opening for draining of water. The Fuse nut is a safety device which melts off in case of excess pressure and temperature-buildup inside the tank, creating an opening for release of water. This Fuse nut is also mounted on this unit assembly. Then, every water heater carries a pressure release valve. This is a simple spring backed port opening valve, which releases the pressure in excess of the preset limits. This valve is also mounted on this assembly unit. This unit assembly is fitted on the water tank using a rubber seal and mechanical fastening. The number of fasteners in most of the cases range from 6 to 9 equispaced nuts and bolts all around the assembly plate as shown in figure 1. In the present invention, the unit assembly also consisting of all the essential features of any water heater system, but the difference being that the unit assembly which is made of a thermoplastic material moulded into a single piece, wherein other components are attached. The constructional features and advantages associated with this unit assembly are described in the foregoing sections. Object of present invention The main object of the present invention is to design a Unit Assembly made up of thermoplastic material such as polycarbonate, polypheniloxide, polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, and polytetramethylene terephthalate, their modified alloys and/or combinations thereof for domestic water heater. Another object of the present invention is to provide a Unit assembly without any welding joints as a single piece. Another object of the present invention is to design a Unit Assembly which is corrosion proof and rust proof. Yet another object of the present invention is to have a Unit assembly without the need of any nickel plating, thus making it environment friendly. Yet another object of the present invention is to have a Unit assembly with better mechanical strength. One more object of this present invention is to develop a cost effective and better performance unit assembly. Another object of this invention is to improve the thermal insulation of the unit assembly, thereby reducing the energy consumption required. Another object of this invention is to provide a shock proof mount for the electrical components, thus reducing the hazards of electrical shock. Yet another object of the invention is to provide a method for the manufacturing of domestic water heater system, wherein said heater system comprising a unit assembly without any welding joints. Another object of the invention is to manufacture a domestic water heater with reduced possibility of any water leakage. Summary of the Invention Accordingly, the present invention provides a circular disc shaped pipe unit assembly for domestic water heater which is made of thermoplastic material. The invention also provides a domestic water heater system comprising above unit assembly. Detailed description of accompanying drawings: Figure 1: Describing the prior art Pipe Unit assembly. Figure 2: Prior art: - Describing the number of weld joints in the present design. Figure 3: Prior art: - Showing the Main Plate. Figure 4: New Design: Describes how so many parts are converted into one part i.e. one composite moulded piece. Figure 5: New Design: describes the fitting required for different mounts. Figure 6: New Design: describes the Heating Element 3 stud fixing. Figure 7: New Design: describes the fixing of the inner pipes. Figure 8: New Design: describing the Inner Water Flow Pipes and Water flow directions. Figure 9: New Design: Describing the New Assembly Plate in various views. The description given below is for illustration only and should not be construed to limit the scope of the invention. Detailed description of the invention The present invention provides a circular disc shaped pipe unit assembly (in the following text, pipe unit assembly is also described as unit assembly) for domestic water heater system, the said disc comprising of outer face and inner face, wherein: a) the outer face is a planar surface having two tubes integrated at right angle to the planar surface, wherein said tubes allow inflow and outflow of water to and from the water heater respectively, wherein said tubes are held parallel to each other, wherein any one of said tube has a provision for attaching a housing for pressure relief valve, and the edges of the planar surface of the disc is having tapered edges, and a drain cum fuse nut assembly attached to the outer face, and b) inner face having a circular channel between outer step and inner step, wherein the said channel has one or more holes for fixing the said unit assembly to the water heater tank; and the inner circle of inner face has one or more holes to provide heating means; auto cut thermostat; thermostat, water inlet pipe and outlet pipe. The unit assembly is made of thermoplastic material which is selected from a group consisting of polycarbonate, polypheniloxide polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate, nylons and their modified alloy compositions. Wall thickness of the unit assembly is in the range of about 4.0 mm to 6.0 mm preferably 5.00 mm, wall thickness of the inlet and outlet pipes are in the range of about 3.0 mm to about 5.0 mm. The inlet pipe and outlet pipe are held parallel to each other by means of a connecting rod and the pipes having threaded ends for connecting to the water inlet and water outlet lines. Another embodiment to the invention, either of the piped has a pressure release valve permanently joined on the pipe itself, for releasing any excess pressure build up above preset limit inside the water storage tank. The heating means is mounted to the unit assembly using rubber "O" ring with at least three studs. The heating means; auto cut thermostat mount; a thermostat mount and water flow pipes are attached to the unit assembly using a rubber "O" ring as washer and bolts/nuts. The drain cum fuse nut assembly attached to the planar surface of the outer face. Another embodiment of the invention relates to unit assembly which is prepared by injection moulding technique. One more embodiment of the invention provides a domestic storage/ water heater system, comprising: (a) an outer housing, (b) a container for storing water, and (c) a single piece circular disc shaped unit assembly which is made of thermoplastic material having a plurality of holes for fixing components of domestic water heater, comprising: (i) an water inlet pipe and water an outlet pipe moulded together with the unit assembly, (ii) an heating means mounted on a mount, (iii) a thermostat fixed on a mount, (iv) an auto cut thermostat on a mount, (v) a drain cum fuse nut assembly, and (vi) housing consisting of pressure release valve, wherein (c), is attached to the inner container. In another embodiment of the invention, the outer housing is made up of a material selected from a metal, metal alloys and thermoplastic material. In another embodiment, the unit assembly is made of a thermoplastic material selected from a group consisting of polycarbonate, polypheniloxide, polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate, Nylons and their modified alloy compositions. Yet another embodiment of the invention provides a water heater system wherein the inlet let pipe is connected to another tube with cross section diameter greater the inlet pipe which allows cold water gushing downwards to the bottom of the inner container and disperse cold water at bottom This object can also be achieved by providing a U bend at the top of the pipe and attaching another pipe at the other end of U bend to release the water at the bottom of the tank. In this arrangement, if the inlet water supply is stopped, then water will start flowing from the inner container through the inlet pipe. In other words, there will be a back flow of water. If this backflow brings down the water level so much that the heating element is exposed out of water, the heating element may burn out. This problem was solved by providing an opening at a level higher than the heating element to avoid siphoning. In another embodiment, either inlet or outlet tubes is provided with a housing for attaching a pressure release valve permanently joined on the pipe itself, for releasing any excess pressure build up above preset limit inside the water storage tank. The pressure release valve comprising a simple spring countered port valve calibrated to release pressure above the preset limit. The pressure preset limit is in the range of 10 psi to 90 psi, preferably about 40 to 75 psi inside pressure. The heating element of the domestic water hater is mounted on the unit assembly using three studs. The heating means is a heating element selected from the group consisting of tubular sheathed heating element, cartridge type heating element, dicast heating element or similar like that. The auto cut thermostat mount, the thermostat mount, the water flow pipes are fastened to the unit assembly by means of bolts and nuts and a rubber "O" ring as washer, wherein the drain cum fuse nut assembly attached to the planar surface of the outer face. Another embodiment of the invention, the unit assembly is attached to the inner water storage or inner container tank using a circular rubber gasket. Further, the system may consist of indicators for power on and power off conditions. The system may consist of insulation material placed between the inner water storage or inner container tank and outer housing. Accordingly, the present invention provides a unit assembly made up of thermoplastic material such as polycarbonate, polypheniloxide, polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, polytetrarnethylene terephthalate or their modified alloys for domestic water heater. The said unit assembly comprising of water flow ports, protection valve, thermostat mounts and heater mount. This Unit assembly is designed to have a thickness of about 4 mm to about 6 mm at the flange end, depending on the water carrying capacity of the model. At the central mounting side, it is designed to have a thickness of about 5 mm to 6 mm for fixing/attaching the mechanical mountings such as thermostat pipe and Heating Element mounting. The thickness of the selected material imparts required strength to the unit to withstand the normal requirement of temperature and pressure. The thermostat of the water heater is normally set to cut off the heating once the water is heated up to 70°C. The selected material is capable of withstanding operating temperature of 140°C. The selected material is not affected by the water and hence makes the component rust proof and corrosion proof. The selected material has no electrical conductivity and as such makes the component electrical shock proof. Thermal conductivity of thermoplastic is also very low and thus the water heated inside will remain hot for a much longer time, thereby covering all the requirement aspects of a Unit assembly. Water inlet - where the cold water supply is connected - is also made out of similar thermoplastic material as used above. Applicant has designed a wall thickness of about 4 mm for this component, since this component is to carry strong threading at one end, where the water inlet is provided to be connected. Also, since we have designed the pipe to be moulded along with the main plate thereby avoiding two weld joints. Water outlet - which is similar to the inlet pipe as explained above. Either of inlet or outlet pipe is further attached with a Pressure release valve as shown in the diagram. This valve is used to release any excess pressure buildup above the preset limit inside the water tank. This valve is a simple spring countered port valve calibrated to release pressure above the preset limit. The housing of this valve is also designed to be moulded on line with the above pipes, thus avoiding another weld joint. Thermostat Pipe - Every water heater is required to carry a thermostat which should cutoff the electricity after the water is heated to the preset temperature. This thermostat needs to sense the temperature of the water heater accurately, so the sensor needs to be placed inside the water through a pipe dipping in the water. A leak proof mounting is required for the purpose. Since the thermostat needs to sense the temperature of the water inside, it needs to be made out of metal only. Applicant has designed a simple bush with "o" ring fitting for this to provide leak proof. Auto cut Pipe - is a Resetable type protection thermostat which cuts off the electricity at a preset temperature and needs to be manually switched back for operation. A similar pipe as described above is required for this also. Heating Element Mounting is the place to fix the heating element. Because of the bigger cross section area, this mounting faces the maximum force and also carries the maximum heat. The mounting needs to be very strong to keep it leak proof. We have designed a three stud mounting for this purpose to accommodate the standard heating element flange. The three studs are mounted from inside side of the tank with a rubber 'o' ring for water sealing. The color of the opening is made in a thickness of 8 mm to impart it very high pressure resisting property. In an embodiment of the invention, wherein the Unit assembly is made out of thermoplastic material such as polycarbonate, polypheniloxide, polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate or their modified alloys to withstand working temperature up to 100 degreesC. Another embodiment of the present invention provides a unit assembly which can overcome the difficulties when they are subjected to varying TEMPERATURE, PRESSURE and WATER ERROSION conditions. In another embodiment of the invention, the thickness of the thermoplastic material used is in the range of about 4.0 mm to about 6.0 mm depending on the capacity of the water heater. The component can withstand water pressure even above 100 psi, at the working temperature. Pressure withstanding Tests Applicant have developed a tool with the above specifications and moulded a few samples in two materials - Polyphenyloxide alloy and Poly Butylene Terephthalate alloy and put both the samples to the same tests. The above unit pipe assembly samples were mounted on a water storage tank and subjected to pressure of 150 psi at room temperature - both samples withstood the conditions comfortably. Subjected to 120 psi at 80 degrees Celsius - both samples withstood the conditions comfortably Subjected to 80 psi at 100 degrees Celsius - both samples withstood the conditions comfortably Advantages of present invention 1. Brass is reactive to water and salts present in the water salts. Copper metal also affected by water. In both the cases, a scale is formed at the inside surface. Plastic is not affected by the water or salts present in the water. 2. In conventional unit assembly, nickel and chrome are plated to protect the unit assembly from fast erosion. This chrome plating forms poisonous chromates, which is avoided by using plastic which is safe. 3. Storage of water in thermoplastic tank for a longer time which would be still safe from medical point of view. 4. Plastic has much lower thermal conductivity in comparison to metals. So heat loss is much lower; hence better efficiency and energy saving is achieved. 5. Metals are conductive to electric current, whereas plastic is not and enables the product electrical shock proof. 6. Metals do corrode with salts contained in water. Especially in case of hard water, the problem is very prominent. Plastic has no reaction, hence provide long life and hard water compatibility. 7. Above all, the present product is much cheaper by 30 to 40% in comparison to metal versions. 8. Present design, the unit assembly is produced by injection moulding process; each piece retains uniform dimensional specifications. Whereas the metal fabrication includes lots of manual forming. Because of this, the rate of production of the current unit assembly is very high. 9. The net weight of the present product is also much less in our design. 10.The raw material used can be easily recycled. I/We claim: 1. A mounting disc unit 400 for a domestic water heater comprising: an outer face 405, wherein said outer face 405 comprises a plurality of tubes 401 & 402, wherein at least one of said plurality of tubes 401 & 402 has provision 403 for attaching a housing for pressure relief valve; and a hole 413 for accommodating a drain and fuse nut assembly; an inner face 406, wherein said inner face 406 comprises a first peripheral projection 407 forming a first inner surface and a second inner projection 408 forming a second inner surface, thereby forming a first channel 409 between said first and second projections, wherein said channel 409 has one or more mounting holes 416 and said second inner surface has one or more openings 410, 411, 412, 414, 415 for mounting of two or more heating elements; characterized in that said mounting disc unit 400 is made of a thermoplastic material and said plurality of tubes 401 & 402 are integrated perpendicular to said outer face 405 and said two or more heating elements are integrally coupled to said inner face 406. 2. The mounting disc unit 400 as claimed in claim 1, wherein said outer face 405 is a planar surface. 3. The mounting disc unit 400 as claimed in any one of claims 1 - 2, wherein said plurality of tubes has an inlet tube 401 and an outlet tube 402 that allow inflow and outflow of water to and from said heater. 4. The mounting disc unit 400 as claimed in any one of claims 1 - 3, wherein said plurality of tubes are held parallel to each other. 5. The mounting disc unit 400 as claimed in any one of claims 1 - 4, wherein said planar outer face has tapered edges. 6. The mounting disc unit 400 as claimed in any one of claims 1 - 5, wherein said inner face 406 is circular. 7. The mounting disc unit 400 as claimed in any one of claims 1 - 6, wherein said two or more heating elements has a heating means and a plurality of temperature regulating elements. 8. The mounting disc unit 400 as claimed in any one of claims 1 - 7, .wherein said thermoplastic material of said disc unit 400 is selected from a group consisting of polycarbonate, polypheniloxide, polyethylene terephthalate, nylons and their modified alloy compositions. 9. The mounting disc unit 400 as claimed in any one of claims 1 - 8, wherein wall thickness of said mounting disc 404 ranges between 4.0 mm to 6.0 mm and preferably 5.00 mm. 10. The mounting disc unit 400 as claimed in any one of claims 1 - 9, wherein wall thickness of said plurality of tubes ranges between 3.0 mm to 5.0 mm. 11. The mounting disc unit 400 as claimed in any one of claims 1-10, wherein said inlet tube 401 and said outlet tube 402 are held parallel to each other by means of a connecting rod. 12. The mounting disc unit 400 as claimed in any one of claims 1-11, wherein said plurality of tubes has threaded ends for connecting said water inlet pipe 701 and said water outlet pipe 702. 13. The mounting disc unit 400 as claimed in any one of claims 1-12, wherein said heating means is mounted to said disc unit 400 by means of a rubber "O" ring 502 with at least three studs 601. 14. The mounting disc unit 400 as claimed in any one of claims 1-13, wherein said temperature regulating elements and said water inlet 701 and outlet pipes 702 are coupled to said inner face 406 of said disc unit 400 by means of bolts and nuts and a rubber "O" ring. 15. The mounting disc unit 400 as claimed in any one of claims 1 - 14, wherein said integrated disc unit is prepared by injection molding. 16. The mounting disc unit 400 as claimed in any one of claims 1-15, wherein said pressure release valve has a spring countered port valve calibrated to release pressure above a preset pressure limit that ranges between 10 psi to 90 psi, and preferably in the range of 40 to 75 psi. 17. The mounting disc unit 400 as claimed in any one of claims 1-16, wherein said heating means is a heating element selected from a group consisting of tubular sheathed heating element, cartridge type heating element or dicast heating element. 18. The mounting disc unit 400 as claimed in any one of claims 1 - 17, wherein said mounting disc unit is made of a thermoplastic material and has one or more openings 410, 411, 412, 414, 415 that accommodates an integrated water inlet pipe 701, which is enclosed by a covering tube 801 of greater cross section, thereby enabling downward gushing of cold water and subsequent disperse, wherein said covering tube 801 has a pore 802 at a level higher than said heating means, thereby avoiding back flow of water through said water inlet pipe 701. 19. A mounting disc unit 400 as claimed in any one of the claims 1 - 18, is used in a domestic water heater system.

Documents:

2565-DEL-2004-Abstract-01-05-2008.pdf

2565-del-2004-abstract.pdf

2565-DEL-2004-Claims-01-05-2008.pdf

2565-DEL-2004-Claims-21-05-2008.pdf

2565-del-2004-claims.pdf

2565-DEL-2004-Correspondence-Others-01-05-2008.pdf

2565-DEL-2004-Correspondence-Others-21-05-2008.pdf

2565-del-2004-correspondence-others.pdf

2565-del-2004-description (complete)-01-05-2008.pdf

2565-del-2004-description (complete)-21-05-2008.pdf

2565-del-2004-description (complete).pdf

2565-DEL-2004-Drawings-01-05-2008.pdf

2565-del-2004-drawings.pdf

2565-del-2004-form-1.pdf

2565-del-2004-form-18.pdf

2565-DEL-2004-Form-2-01-05-2008.pdf

2565-del-2004-form-2.pdf

2565-del-2004-form-26.pdf

2565-del-2004-form-3.pdf

2565-del-2004-form-9.pdf

abstract-01-05-2008.jpg