DESC:FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10 and rule 13)
Title: TEMPERATURE RESISTANT WATER PIPES AND METHOD THEREOF
APPLICANT DETAILS:
(a) NAME: A. O. Smith India Water Products Pvt Ltd
(b) NATIONALITY: IN
(c) ADDRESS: Plot No. 300, KIADB Industrial Area, Phase - 2, Harohalli, Kanakapura Taluk,
Ramanagara District, 562112, Karnataka.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed.
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TEMPERATURE RESISTANT WATER PIPES AND METHOD THEREOF
FIELD OF THE INVENTION
The present invention relates to the field of water heater. Particularly, the invention provides temperature resistant water pipes and method thereof. The invention also provides water heater based on the temperature resistant water pipes and method thereof.
BACKGROUND OF THE INVENTION
The following background discussion includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
The water heaters and the inlet and outlet tubes carry hot water. In conventional water heaters, the inlet and outlet tubes are generally made of stainless steel or other metal, which can withstand continuous hot water exposure and have good corrosion resistance. A plastic sleeve is therefore fixed only on the metal tube (through insert molding or any other technique), which is assembled to the inlet/outlet metal nipple, that is welded to the tank, through interference fit. However, this is not an efficient mechanism/design, in terms of cost and manufacturing process, for the water pipes to handle the extreme temperature in the water heater.
In several water heaters, a heat trap assembly based on a housing, O-rings and heat trap flaps is assembled inside the inlet tube for improving the standing loss characteristic of the water heater. This design and process has disadvantages like higher material cost and higher labor cost for part manufacturing and assembly.
It is clear that there are problems in terms of high number of components, high cost and inefficient manufacturing as well as assembly process when it comes to the conventional designs for inlet/outlet tubes. Hence, there is a need to address these issues by using a new and novel design of inlet and outlet tubes using engineering plastic which are easy to manufacture/assemble, cost effective and which can withstand hot water exposure and have corrosion and erosion resistant properties.
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OBJECT OF THE INVENTION
A primary object of the present invention is to overcome the drawbacks associated with the prior art.
Another object of the invention is to provide temperature resistant water pipes and method thereof.
Yet another object of the invention is to provide integrated inlet and outlet tubes with multiple useful features integrated into a single design.
Yet another object of the invention is to provide integrated inlet and outlet tubes which eliminate aggregation/ assembly of multiple components.
Yet another object of the invention is to provide integrated inlet and outlet tubes with integrated heat trap portion.
Yet another object of the invention is to provide integrated inlet and outlet tubes which eliminates housing portion and extra sealing.
Yet another object of the invention is to provide integrated inlet and outlet tubes with a simple process of manufacturing.
Yet another object of the invention is to provide integrated inlet and outlet tubes with a single step of manufacturing process.
Yet another object of the invention is to provide water heater based on temperature resistant water pipes.
Yet another object of the invention is to provide a cost effective water heater based on temperature resistant water pipes and method thereof.
Yet another object of the invention is to provide molded inlet plastic tubes and extruded outlet plastic tubes, which are resistant to corrosion and have ability to withstand long exposure to hot water.
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Yet another object of the invention is to provide a water heater tank with metal spuds having inlet and outlet tubes made from plastic that can withstand long exposure to hot water.
Yet another object of the invention is to provide a new design of inlet and outlet tubes with several features integrated into a single design.
SUMMARY OF THE INVENTION:
In an aspect, the invention provides a water heater inlet/outlet pipe, based on a plastic material, comprising:
a) an injection molded inlet tube comprising crush ribs 101 for easy assembly of the inlet tube into a metal nipple 201 using interference fit wherein said inlet tube comprises the following characterizing features:
i) plurality of diffuser holes 102, covering less than 50% of the circumferential area of the tube, allowing slow diffusion of cold water into the water heater and ensuring that cold water enters only in the bottom area of the tank thus improving the mixing factor of the water heater;
ii) plurality of ribs 103, 902 for introducing poke yoke assembly into a plurality of key-hole slot 301 in a horizontal water heater;
iii) plurality of heat trap flaps for easy assembly into the inlet tube using ribs 401 on the side, which improves the standing loss;
b) an outlet tube, comprising an extruded cut-to-length secondary plastic tube 702 assembled to the molded primary outlet tube 701, wherein said outlet tube comprises variable length secondary tube which is assembled with the primary outlet tube using snaps 704, for delivering hot water from the top of the tank, and ensuring that the tank can hold the rated volume of water.
In an aspect of the Invention, there is provided a method of functioning of the inlet/outlet pipe as described, comprising the steps of:
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a) receiving the cold water to be heated through inlet pipe wherein the heat trap flaps are opened facilitating the receiving of the cold water;
b) maintaining the heat trap flaps in closed position during the heating process;
c) flowing of the heated water through the outlet pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of preferred embodiments, are better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings exemplary constructions of the invention; however, the invention is not limited to the specific methods and system disclosed. In the drawings:
Figure 1(A), (B) and (C): illustrates designing of the inlet tube of water heater
Figure 2: illustrates an assembly of the inlet tube into a water heater tank
Figure 3(A) and 3(B): illustrates the use of a key-hole slot 301 in the water heater tank orifice and a rib 103 in the inlet plastic tube
Figure 4(A) and 4(B): illustrates heat trap flap 401 and an integration of heat trap flaps into the inlet tube design
Figure 5(A), (B) and (C): illustrates another embodiment of the inlet tube design
Figure 6(A) and (B): illustrates ribs with a metal clip 601 for retention of the inlet tube inside the water heater tank
Figure 7(A), (B) and (C): illustrates designing of the outlet tube of water heater
Figure 8(A), (B), (C) and (D): illustrates another embodiment of the outlet tube design
Figure 9(A), (B) and (C): illustrates an embodiment of outlet pipe that is specific for horizontal water heaters
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Figure 10: illustrates an embodiment of the inlet tube assembled with the metal nipple using threads 1001
Figure 11: illustrates an embodiment of the inlet tube with the diffuser holes 102 covered on both sides with extruded ribs 1101
Figure 12(A), (B), (C), (D), (E): illustrates an embodiment of the inlet and outlet tubes with flange design for easy assembly with the tank that helps reduce the total number of components in the inlet/outlet assembly.
DETAILED DESCRIPTION OF THE INVENTION:
The details of the invention can be understood more clearly in combination with the figures and the description of the embodiments of the present invention. However, the specific embodiment of the present invention described herein, only for the purpose of interpreting the present invention, cannot be construed in any way as a limitation of the present invention. Under the guidance of the present invention, the technician may conceive any possible variation/modification based on the present invention, which shall be regarded as belonging to the scope of the present invention.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items.
It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice
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or testing of embodiments of the present invention, the preferred systems and methods are now described.
The disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms.
In the following description of some embodiments, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration, embodiments of the disclosure that may be practiced. It is to be understood that other embodiments may be utilized.
The inlet and outlet pipelines are also referred as tubes or pipes in the present specification.
The invention provides temperature resistant water pipes and method thereof. The invention in an aspect provides a water heater based on temperature resistant water pipes and method thereof.
In an embodiment, the invention provides molded inlet plastic tubes and extruded outlet plastic tubes, which are resistant to corrosion and have ability to withstand long exposure to hot water and still meeting industry requirements of tube strength.
In an embodiment, the inlet and outlet tubes are made of engineered plastic instead of corrosion resistant metal like stainless steel and are therefore less costly. The plastic inlet tubes are made using injection molding while the outlet plastic tubes are made using extrusion, thus reducing the overall cost.
In an embodiment, the invention provides a water heater inlet/outlet pipe, based on a plastic material, comprising:
a) an injection molded inlet tube comprising crush ribs 101 for easy assembly of the inlet tube into a metal nipple 201 using interference fit wherein said inlet tube comprises the following characterizing features:
i) plurality of diffuser holes 102, covering less than 50% of the circumferential area of the tube, allowing slow diffusion of cold water into the water heater and ensuring that
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cold water enters only in the bottom area of the tank thus improving the mixing factor of the water heater;
ii) plurality of ribs 103, 902 for introducing poke yoke assembly into a plurality of key-hole slot 301 in a horizontal water heater;
iii) plurality of heat trap flaps for easy assembly into the inlet tube using ribs 401 on the side, which improves the standing loss;
b) an outlet tube, comprising an extruded cut-to-length secondary plastic tube 702 assembled to the molded primary outlet tube 701, wherein said outlet tube comprises variable length secondary tube which is assembled with the primary outlet tube using snaps 704, for delivering hot water from the top of the tank, and ensuring that the tank can hold the rated volume of water.
In an embodiment, the inlet pipe comprises single or multiple slots for O-rings 501, for preventing water leakage.
In an embodiment, the inlet pipe comprises male threads 503, as part of the moulded plastic design, for attaching the hose while installing the water heater, thus eliminating the secondary process of making threads on inlet metal nipple 201.
In an embodiment, the inlet pipe comprises bigger and stronger ribs 502 in the place of crush ribs wherein the ribs along with a metal clip 601 retains the inlet tube inside the water heater tank.
In an embodiment, the inlet tube is assembled with the metal nipple using threads 1001.
In an embodiment, the diffuser holes 102 are covered on both sides with extruded ribs 1101.
In an embodiment, the outlet tube comprises a bent primary outlet tube to reach the top of the water heater tank in case of horizontal water heaters.
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In an embodiment, the outlet tube comprises a bent secondary outlet tube 1204 that is connected to the primary outlet tube through snaps 1203 to reach the top of the water heater tank in case of horizontal water heaters.
In an embodiment, the outlet tube comprises heat trap flap integration 901 and key-hole rib 902 ensuring poke yoke assembly inside the water heater tank to ensure that the outlet tube reaches the top of the tank.
In an embodiment, the inlet and outlet tubes comprise plastic body structure, clip locating ribs 502 and 804, heat trap flap integration similar to 104, key-hole rib for poke yoke assembly similar to 103 and 902, male threads for hose installation 801 and clip design component 802 for retention at high hydrostatic pressures.
Figure 1 illustrates an embodiment of the inlet tube while figure 2 illustrates configuration of the inlet tube into a water heater tank.
Figure 1(A), (B) and (C) illustrates an embodiment showing inlet tube of water heater. As shown in this figure, the inlet tube of water heater is generally made of plastic which can withstand long exposure to hot water. The use of plastic allows for injection moulding, to be used as a manufacturing process, that helps in integrating other functional features.
Figure 1(A) illustrates the perspective view of the water inlet tube. As shown in said figure, the inlet tube bottom end has crush ribs 101 which allows easy assembly of the inlet tube into the metal nipple 201 using interference fit. Figure 1(B) illustrates another view of the water inlet tube showing diffuser holes 102 integrated in the plastic tube that allows slow diffusion of cold water into the water heater to achieve good mixing factor. In another embodiment, the diffuser holes cover less than 50% of the circumferential area of the tube. As illustrated in Figure 3, there are plurality of key-hole slot 301 in the water heater tank orifice and a rib 103 in the inlet plastic tube for introducing poke yoke assembly for horizontal water heaters where the orientation of the diffuser holes is critical to achieve a good mixing factor. Figure 3(A) and 3(B) represents the front view of the keyhole slot facilitating the smooth deposition of the rib 103 and 902 within the
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horizontal water heater. The integrated functioning of diffuser holes with key-hole slot 301 and rib 103 in the inlet plastic tube ensures that cold water enters only in the bottom area of the tank which improves the mixing factor of the water heater.
In an embodiment, the diffuser holes and key hole design feature are configured to work in alignment.
Figure 1(C) illustrates front view of the water inlet tube which comprises provision 104 for heat trap flaps (also shown in Fig 4(A) and (B)) integrated into the inlet tube design.
Fig 4 shows provision 104 made in the inlet tube for single or multiple heat trap flaps assembly as needed for improving the standing loss. The heat trap flaps are designed for easy assembly into the inlet tube using ribs 401 on the side. Figure 4(A) illustrates the bell-shaped heat trap flaps with a curved resting base and Figure 4(B) represents the cross section view of the provision 104 in which the heat traps are deposited.
Figure 2 illustrates assembly of the inlet tube into a water heater tank. In this figure, the inlet water tube is integrated into the water heater via an orifice.
Figure 5(A), (B) and (C) illustrates another embodiment of the inlet tube. In such embodiment the inlet tube comprises single or plurality of slots for O-ring 501 for preventing water leakage.
In an embodiment, the male threads 503 are integrated as a part of the inlet tube. The threads facilitate attachment of the hose while installing the water heater at a user’s/customer’s place. The threads are a part of the moulded plastic design which eliminates the secondary process of making threads on the inlet metal nipple 201.
In another embodiment, the inlet tube is assembled with the metal nipple using threads 1001, as illustrated in Figure 10.
In an embodiment, Figure 6(A) and (B) illustrate ribs 502 with a metal clip 601 for retention of the inlet tube inside the water heater tank. The ribs 502, along with a metal clip 601 help in retention of the inlet tube inside the water heater tank. Said figures show the assembly of the metal clip 601 through holes in the metal nipple for proper retention
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of the inlet tube inside the water heater tank when subjected to high water pressure/ hot water pressure as required by the industry standards.
Figure 6(A) and 6(B) illustrates the positioning of clip for maintaining the stronghold of the metal nipple to the inlet tube via ribs 502. The clip helps in preventing any accidental event due to hot water pressure.
In an embodiment, Figure 7 and 8 illustrates outlet tube of water heater. The complete outlet tube comprises of a primary tube 701 which is a moulded part and a secondary tube 702 which is an extruded part. Such embodiment comprises a variable length secondary tube which is assembled with the primary outlet tube using means like snaps 704. In this embodiment, the outlet tube has two main functions: first function is to deliver hot water from the top of the tank, and second function is to ensure that the tank can hold the rated volume of water in it. Both these functions require the use of a long outlet tube which reaches till the top of the water heater tank. To achieve this, present invention proposes an extruded cut-to-length secondary plastic tube 702 that is assembled to the primary outlet tube 701 using snaps 704.
Figure 7(A) illustrates the perspective view of the outlet tube of the water heater, where the outlet tube is composed of primary tube 701, in which the secondary tube 702 is assembled using the snaps 704. Figure 7(B) and Figure 7(C) illustrates the front view and the side view of the outlet tube respectively, where the side view illustrates the protruding feature (snaps) on both sides of the primary plastic tube 701. The said protruding feature mate with the secondary tube 702 via an orifice or any suitable clubbing design such that the secondary plastic is well retained within the primary plastic tube 701.
Figure 8 illustrates another embodiment of the outlet tube design which is similar to the design of the inlet tube as shown in Figure 5. An O-ring sits in the slot 803 which helps in preventing water leakage. The ribs 804, along with a metal clip 802 helps in retention of the outlet tube inside the water heater tank. Figure 8(D) shows male threads for hose installation 801 and clip 802 for retention of the tubes even at high hydrostatic pressures.
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Figure 9(A), (B) and (C) illustrates an embodiment of the outlet tube that is specific for horizontal water heaters. In this embodiment a bent outlet tube is provided. Such embodiment is specific to horizontal water heaters where a bent tube is needed to reach the top of the water heater tank. The key-hole slot 902 ensures poke yoke assembly of the outlet tube inside the water heater tank which is needed to ensure that the outlet tube reaches the top of the tank. This can be achieved using hot-forming of the extruded tube. Even after adding the cost of secondary operation of hot forming, this is much more cost effective than using a stainless steel or any other corrosion resistant metal tube.
Figure 10 illustrates an embodiment of the inlet tube assembled with the metal nipple using threads 1001. The figure shows integration of threads 1001 introduced, in the middle section, of the inlet tube and at the portion where the metal nipple mates with the inlet tube. The threads 1002 at the end are used for attaching the hose while installing the water heater at customer’s place.
Figure 11 discloses another embodiment of the inlet tube where the diffuser holes 102 are covered on both sides with extruded ribs 1101. These ribs, along with the poke yoke assembly feature described in figures 3 and 5, ensure that cold water flows only towards the bottom of the tank, thereby further contributing to a better mixing factor.
Figure 12 discloses another embodiment which helps in eliminating the metal spud 201 from the tank assembly. Figure 12(A) shows the inlet tube and Figure 12(B) shows the primary outlet tube. Both look identical with just 2 main differences:
1. The inlet tube has a closed end 1201 while the primary outlet tube has an open end 1202.
2. The primary outlet tube has snaps 1203 for the assembly of the extruded secondary outlet tube 1204.
The extruded secondary outlet tube 1204 can either be a single straight tube for vertical water heaters or it can be a bent or joint tube for horizontal water heaters as shown in Figure 12(C).
Both the inlet and primary outlet tubes have a flange 1205. As shown in Figure 12(D), the tank head has two metal flanges 1206, one each for inlet and outlet, that are welded to the tank.
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Flanges 1205 and 1206 are assembled using bolts and nuts and a gasket may be used between the flanges to ensure a seal proof joint between the tank and the inlet/outlet tubes, as shown in Figure 12(E).
This embodiment is the most efficient in terms of reducing components and cost by incorporating several features into least number of components.
In another embodiment, the inlet tube comprises diffuser holes 102, which are covered on both sides with extruded ribs 1101. These ribs, along with the poke yoke assembly feature as described above, ensures that cold water flows only towards the bottom of the tank, thereby further contributing to a better mixing factor, as illustrated in Figure 11.
Key features of the Invention:
The Invention provides temperature resistant water pipes and water heater based on the same, with following non-limiting essential features:
• Water heater tank with metal spuds having inlet and outlet tubes made from plastic that can withstand long exposure to hot water.
• Inlet tube and primary outlet tube made from injection moulding technique
• Secondary outlet tube made using extrusion and cut-to-length pieces being used for different capacity water heater tanks.
• Inlet tube having crush ribs for assembly with metal nipple using interference fit
• Inlet tube with diffuser holes on less than 50% of the circumferential surface
• Inlet tube with a rib and a key hole slot in the tank orifice to fix at a specific position in the inlet metal nipple to ensure that cold water enters bottom of the water heater tank
• Outlet tube for horizontal water heaters with a rib and a key hole slot in the tank orifice to fix at a specific position in the outlet metal nipple to ensure that hot water is withdrawn from the top of the water heater tank
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• Inlet tube with multiple slots for installation of heat trap flaps inside it
• Inlet tube and primary outlet tube having male threads as a part of the moulded design for fixing of hose at customer’s place
• Secondary outlet tube that is cut-to-length for different capacity water heater tanks, assembled to the primary outlet tube using snap fit design
• Clip fixed through holes on the inlet and outlet metal nipples which is positioned between 2 ribs on the inlet and outlet plastic tubes respectively for retention of the tubes inside the water heater tank for high hydrostatic as required by industry standards. ,CLAIMS:We Claim:
1. A water heater inlet/outlet pipe, based on a plastic material, comprising:
a) an injection molded inlet tube comprising crush ribs 101 for easy assembly of the inlet tube into a metal nipple 201 using interference fit wherein said inlet tube comprises the following characterizing features:
i) plurality of diffuser holes 102, covering less than 50% of the circumferential area of the tube, allowing slow diffusion of cold water into the water heater and ensuring that cold water enters only in the bottom area of the tank thus improving the mixing factor of the water heater;
ii) plurality of ribs 103 for introducing poke yoke assembly into a plurality of key-hole slot 301 in a horizontal water heater;
iii) plurality of provision for heat trap flaps for easy assembly into the inlet tube using ribs 401 on the side, which helps in improving the standing loss;
b) an outlet tube, comprising an extruded cut-to-length secondary plastic tube 702 assembled to the molded primary outlet tube 701, wherein said outlet tube comprises variable length secondary tube which is assembled with the primary outlet tube using snaps 704, for delivering hot water from the top of the tank, and ensuring that the tank can hold the rated volume of water.
2. The water heater pipe assembly as claimed in claim 1, wherein the outlet pipe comprises a heat trap flap integration 901, a key-hole rib for poke yoke assembly 902 and a male thread for hose installation 801.
3. The water heater inlet/outlet pipe as claimed in claim 1, wherein the inlet pipe comprises single or multiple slots for O-rings 501 and outlet pipe comprises single or multiple slots for O-rings 803, for preventing water leakage.
4. The water heater inlet/outlet pipe as claimed in claim 1, wherein the inlet pipe comprises male threads 503, as part of the moulded plastic design, for attaching the hose while
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installing the water heater, thus eliminating the secondary process of making threads on inlet metal nipple 201.
5. The water heater inlet/outlet pipe as claimed in claim 1, wherein the inlet pipe comprises bigger and stronger ribs 502 in the place of crush ribs wherein the ribs along with a metal clip 601 retains the inlet tube inside the water heater tank.
6. The water heater inlet/outlet pipe as claimed in claim 1, wherein the outlet pipe comprises bigger and stronger ribs 804 in the place of crush ribs wherein the ribs along with a metal clip 802 retains the outlet tube inside the water heater tank.
7. The water heater inlet/outlet pipe as claimed in claim 1, wherein the inlet tube is assembled with the metal nipple using threads 1001.
8. The water heater inlet/outlet pipe as claimed in claim 1, wherein the diffuser holes 102 are covered on both sides with extruded ribs 1101.
9. The water heater inlet/outlet pipe as claimed in claim 1, wherein outlet tube comprises a bent primary outlet tube to reach the top of the water heater tank in case of horizontal water heaters.
10. The water heater inlet/outlet pipe as claimed in claim 1, wherein the outlet tube comprises a bent secondary tube 1204 to reach the top of the water heater tank in case of horizontal water heaters.
11. The water heater inlet/outlet pipe as claimed in claim 1, wherein the inlet and outlet tubes have a flange 1205 for easy assembly with the water heater tank.
12. A method of functioning of the inlet/outlet pipe as claimed in claim 1, comprising the step of:
a) receiving the cold water to be heated through inlet pipe wherein the heat trap flaps are opened facilitating the receiving of the cold water;
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b) maintaining the heat trap flaps in closed position during the heating process;
c) flowing of the heated water through the outlet pipe.