Claims:WE CLAIM:
1. A sealing mechanism for boss part assembly 100, said mechanism comprising:
a threaded plug 114 characterized in that cylindrically machined from a single metal block to form a head portion 153 consisting of a threaded portion 154 with a bottom portion 155 and a partial hexagonal shaped hollow portion 156 within the head portion 153, wherein the hollow portion 156 is in circular shape continuing from the head portion 153 passing through a body 160 of the metal block until touching multiple holes 158 at bottom of the plug 114, wherein the threaded portion 154 secures the threaded plug 114 onto a smaller threaded portion 118 of a metallic subassembly part 102; and
a mechanical gasket 111 having shape of a torus is placed between bottom portion 155 and bottom portion 147 of the smaller hollow portion 145 of the metallic part 102, wherein the threaded plug 114 when tightened to the smaller threaded portion 118 using a hexagonal shaped flat tip screwdriver or Allen key, presses the gasket 111 against the bottom portion 147, thereby bulging the gasket 111 sideways and providing a sealing mechanism for the boss part assembly 100.

2. The sealing mechanism as claimed in claim 1, wherein when the plug is secured to the smaller hollow portion 145 of the metallic part 102, gap between the body 160 of the plug and the smaller hollow portion 145 is in the range 0.03mm to 0.700mm.

3. The sealing mechanism as claimed in claim 1, wherein the plug 114 consist of multiple holes 158 at bottom of the plug 114 for safe passage of gas to and from the composite gas cylinder.

4. The sealing mechanism as claimed in claim 1, wherein the threaded plug 114 is made from any non-corrosive metal preferably high grade stainless steel or brass.

5. A method for sealing mechanism for boss part assembly 100, said method comprising following steps:
Step a. cleaning larger and smaller hollow portion 144,145 of the metallic subassembly part 102;
Step b. placing a mechanical gasket 111 onto bottom portion 147 of the smaller hollow portion 145 of the metallic subassembly part 102;
Step c. inserting a threaded plug 114 onto the smaller hollow portion 145 of the metallic subassembly part 102; and
Step d. fastening the threaded plug 114 using a hexagonal shaped flat tip screwdriver or Allen key or any other mechanical tool.

6. The method as claimed in claim 5, wherein the metal subassembly part 102 is made from any non-corrosive metal preferably high grade stainless steel or brass. , Description:BACKGROUND
Technical Field
The embodiments herein generally relate to a composite gas cylinders and more particularly to, but not limited to, a boss part assembly for the composite cylinder which provides improved sealing mechanism for the Boss part assembly so as to prevent gradual leakage of any type of gases such as liquefied petroleum gas, compressed natural gas, oxygen, etc. from high or low pressure composite cylinders.

Description of the Related Art
Traditional steel cylinders are heavy and difficult to handle, and they generate high logistical and maintenance costs. Unaesthetic as they are, they are easily damaged and therefore steel cylinders can be explosive under certain circumstances. Steel cylinders are corrosive devices and many gas distributors have issues regarding this. Also, with thieves who steal them for scrap. From the consumers point of view, steel cylinders are unsafe if they are not well managed. The gas level cannot be checked and users can be affected by the weight and the risk of explosion.

Disadvantages of gas cylinders are as follows Difficult to handle - Heavy in weight, Corrosive, Explosion risk - Spark susceptible, Unfavorable environmental effects, unable to check the level of gas, Easily damaged, Metal thefts, Aesthetically unappealing, High logistic and maintenance cost, very old technology.

To overcome this disadvantages, new age composite cylinder has been developed. Composite cylinder is a three-layer cylinder made up of a blow-molded HDPE inner liner, covered with composite layer of polymer-wrapped fiber glass and fitted with a HDPE outer jacket. The second layer is a composite layer of polymer-wrapped fibre glass. And the third and last layer to the LPG composite cylinder is an HDPE outer jacket. These new-age composite cylinders have multiple advantages over the existing steel cylinders. These cylinders are lightweight. The weight of a composite cylinder is half of its steel counterpart. Moreover, these cylinders have a translucent body that helps customers to accurately check the LPG level against light. This will help customers plan their next refill easily. These cylinders are also rust-free and do not corrode and reduces the chances of leaving stains and marks on surfaces. Designed in such a way that these cylinders make them visually appealing and ideal for the modern kitchens of today. You can replace the existing LPG steel cylinders with composite cylinders.

However, composite gas cylinders may suffer from gradual leakage from Boss part integration over a period of time. This may be due to poor integration of the boss part into neck of the composite cylinder. Many a times while refilling the cylinder, the valve system or the regulator installation into the boss part may result in some minor gaps left between the Boss part and the cylinder. Also, long-term damage (ageing) and failure mechanisms of composites may result in gas leakage especially from the Boss part of the cylinder. Wherein the plastic and metal part of the Boss assembly gets detached or peel off from each other over a period of time due to continuous use, exposure to high temperature, handling, refilling of gas, etc. resulting in gradual leakage of gas from the composite cylinder where the Boss part is connected.

Another aspect from where leakage may occur is through threaded plugs. At present, ribbed threaded plugs as shown in Fig. 2 are the most commonly used threaded plugs in the Boss part assembly. These plugs have got one or more horizontal grooves on stem (or body) where O ring is fitted. The threaded plug is fastened to the metal part of the Boss part assembly. While fastening, there are chances that the ribs or the O ring may rub against the metal part and may get bruised or damaged. Thus. if leaving such damaged O ring unattended for long time may result in gradual leakage of gas from the threaded plug. Such percentage of gas leakage through the Boss part is beyond standard norms and is not acceptable by Industry standards. Also, during maintenance or otherwise, the threaded plug needs to be removed and checked for any damages in the O ring, if required will need replacements, which in turn increases the maintenance cost.

Accordingly, there remains a need for an improved sealing mechanism for the Boss part assembly especially at the threaded plug connection which will prevent leaking any gas over a longer period of time and thereby providing ideal sealing of the integration between the cylinder body and the Boss part with almost zero leakage of the gas from the composite cylinder.

SUMMARY
The present embodiment herein discloses an improved sealing mechanism for the Boss part assembly. The mechanism includes a threaded plug characterized in that cylindrically machined from a single metal block to form a head portion consisting of a threaded portion with a bottom portion and a partial hexagonal shaped hollow portion within the head portion, wherein the hollow portion is in circular shape continuing from the head portion passing through a body of the metal block until touching multiple holes at bottom of the plug, wherein the threaded portion secures the threaded plug onto a smaller threaded portion of a metallic subassembly part; and a mechanical gasket having shape of a torus is placed between bottom portion and bottom portion of the smaller hollow portion of the metallic part, wherein the threaded plug when tightened to the smaller threaded portion using a hexagonal shaped flat tip screwdriver or Allen key, presses the gasket against the bottom portion, thereby bulging the gasket sideways and providing a sealing mechanism for the boss part assembly.

In an embodiment, the plug may be secured to the smaller hollow portion of the metallic part, gap between the body of the plug and the smaller hollow portion 145 is in the range 0.03mm to 0.700mm. In an embodiment, the plug consist of multiple holes at bottom of the plug for safe passage of gas to and from the composite gas cylinder.

In an example embodiment, the threaded plug may be made from any non-corrosive metal preferably high grade stainless steel or brass.

A method for sealing mechanism for boss part assembly, said method has following steps: Step a. cleaning larger and smaller hollow portion of the metallic subassembly part; Step b. placing a mechanical gasket onto bottom portion of the smaller hollow portion of the metallic subassembly part; Step c. inserting a threaded plug onto the smaller hollow portion of the metallic subassembly part; and Step d. fastening the threaded plug using a hexagonal shaped flat tip screwdriver or Allen key or any other mechanical tool.

In an embodiment, the metal subassembly part 102 may be made from any non-corrosive metal preferably high grade stainless steel or brass.

In one embodiment, the larger threaded portion located on the upper side of the metallic body secures any type of adaptors or connectors with the assembly for connecting gas regulator onto the composite cylinder.

These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS
Reference will be made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments:

The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:

FIG. 1 illustrates a perspective view of a typical Boss part assembly of a composite gas cylinder;

FIG. 2 illustrates most commonly used threaded plugs in the Boss part assembly of a composite gas cylinder;

FIG. 3 illustrates a front schematic sectional view of the Boss part assembly detailing metal and plastic subassembly parts having a sealing mechanism using an ‘O’ ring along with a threaded plug according to an embodiment mentioned herein;

FIG. 4 illustrates a front schematic view of a plastic subassembly part integrated on to the metallic body of the metal subassembly part according to an embodiment mentioned herein; and

FIG. 5 illustrates a perspective view of a threaded plug which is part of the Boss part assembly according to an embodiment mentioned herein; and
FIG. 5A illustrates a front schematic view of a threaded plug which is part of the Boss part assembly according to an embodiment mentioned herein.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.

Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.

References in the specification to “one embodiment” or “an embodiment” member that a particular feature, structure, characteristics, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. That is, those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. In some instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail. All statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.

Accordingly, there remains a need for an improved sealing mechanism for the Boss part assembly especially at the threaded plug connection which will prevent leaking any gas over a longer period of time and thereby providing ideal sealing of the integration between the cylinder body and the Boss part with almost zero leakage of the gas from the composite cylinder.

The present embodiments herein provides an improved sealing mechanism for the Boss part assembly so as to prevent gradual leakage of any type of gases such as liquefied petroleum gas, compressed natural gas, oxygen, etc. from high or low pressure composite cylinders. The present embodiment also describes method in which the sealing mechanism is installed in Boss part assembly. Referring now to the figures, more particularly from FIG. 1 to FIG. 5A, where similar reference characters denote corresponding features consistently throughout the figures, preferred embodiments are shown.

FIG. 1 illustrates a perspective view of a typical Boss part assembly of a composite gas cylinder. The boss part assembly 100 includes metal subassembly part 102, a plastic subassembly part 104 and a threaded plug 106. The metal subassembly part 102 of the present embodiment may be fabricated or machined to form a specific shape and size which is then blow molded with High-density polyethylene (HDPE) material over the metal subassembly part 102. The threaded plug 106 is then bolted or fastened to the metal subassembly part 102.

In an example embodiment, the metal subassembly part 102 and the threaded plug 106 may be made from any non-corrosive metal preferably high grade stainless steel or brass.

In an embodiment, the boss part 100 which may also be termed as universal boss is made from high grade steel so that the boss part is insulated from regular wear and tear on any number of screwing/ unscrewing operations of brass valve. The boss part 100 is suitable to operate at a temperature range -60° C to 200° C. In an example embodiment, a composite cylinder body may consist of the gas tight inliner , the fiber glass composite layer and the outer casing without the boss part.

FIG. 2 illustrates most commonly used threaded plugs in the Boss part assembly of a composite gas cylinder. These plugs have got one or more horizontal grooves on stem (or body) where O ring is fitted. The threaded plug is fastened to the metal part of the Boss part assembly. While fastening, there are chances that the ribs or the O ring may rub against the metal part and may get bruised or damaged. Thus. if leaving such damaged O ring unattended for long time may result in gradual leakage of gas from the threaded plug.

FIG. 3 illustrates a front schematic sectional view of the Boss part assembly 100 detailing metal 102 and plastic subassembly parts 104 having a sealing mechanism using an ‘O’ ring along with a threaded plug 114 according to an embodiment mentioned herein.
In an embodiment, the metal subassembly part 102 consist of a single cylindrical hollow metallic part 113 which is having a machined outer metallic body. The metal subassembly part 102 has a larger threaded portion 116 which is located on within upper side of the metallic part 113, which may secure any type of adaptors or connectors with the Boss part assembly 100 for connecting gas regulator on to the composite cylinder.

In another embodiment, the metal subassembly part 102 may also include a smaller threaded portion 118 on the lower side of the metallic part 113. The smaller threaded portion 118 helps to safely secure or bolt the threaded plug 114 with the metallic subassembly part 102.

In an embodiment, the boss part assembly 100 may be fused to the composite cylinder body at a depression joining the plastic part subassembly 104 with the composite cylinder body.

FIG. 4 illustrates a front schematic view of a plastic subassembly part 104 integrated on to the metallic body of the metal subassembly part 102 according to an embodiment mentioned herein. In an example embodiment, the plastic subassembly part 104 may be blow molded onto the metal subassembly part 102. The blow molding operation may fill indentations, contours, v-grooves and multiple holes of the metallic part with High-density polyethylene (HDPE) material. In an embodiment, the hollow portions within the metallic subassembly part 102 may or may not be filled with HDPE.

In one embodiment, the multiple holes in the metal subassembly part 102 may be filled with plastic material within the holes such that the HDPE material 150, 152 joins together through the holes and locks the plastic subassembly part 104 with the metallic subassembly part 102 such that they form an inseparable linking with the metallic part 102. Thus a very strong bond may be created between the metal subassembly part 102 and the plastic subassembly part 104.

FIG. 5 illustrates a perspective view of a threaded plug 114 which is part of the Boss part assembly 100 according to an embodiment mentioned herein. In an embodiment, the threaded plug 114 includes a head portion 153 which is having a threaded portion 154 for securely connecting the threaded plug 114 with the metallic subassembly part 102. In an additional embodiment, the plug 114 may have a hexagonal shaped hole 156 starting from top of the plug 114, passing through body 160 from within the plug and touching a multiple holes 158 at bottom of the plug 114 for safe passage of gas to and from the composite gas cylinder. This hexagonal shape is provided for bolting or securing the threaded plug 114 with the metallic subassembly part 102 using hexagonal shaped tools. FIG. 5A illustrates a front schematic view of a threaded plug which is part of the Boss part assembly according to an embodiment mentioned herein.

In an embodiment, the sealing mechanism consist of a threaded plug 114 which is cylindrical in shape and machined from a single metal block to form a head portion 153 which is consisting of a threaded portion 154 with a bottom portion 155 and a partial hexagonal shaped hollow portion 156 within the head portion 153. The hollow portion 156 is in circular shape continuing from the head portion 153 passing through a body 160 of the metal block until touching multiple holes 158 at bottom of the plug 114.

In an embodiment, the threaded portion 154 secures the threaded plug 114 onto a smaller threaded portion 118 of a metallic subassembly part 102. Further, the sealing mechanism consist of a mechanical gasket 111 having shape of a torus which may be is placed between bottom portion 155 and bottom portion 147 of the smaller hollow portion 145 of the metallic part 102, wherein the threaded plug 114 when tightened to the smaller threaded portion 118 using a hexagonal shaped flat tip screwdriver or Allen key, presses the gasket 111 against the bottom portion 147, thereby bulging the gasket 111 sideways and providing a sealing mechanism for the boss part assembly 100.

In an example embodiment, when the plug is secured to the smaller hollow portion 145 of the metallic part 102, the gap between the body 160 of the plug 114 and the smaller hollow portion 145 is in the range 0.03mm to 0.700mm.

In an advantageous embodiment, the boss part assembly provides below advantages:
a) Simple process of assembly without damaging of critical parts without requiring any highly skilled person.
b) Time saving assembly due to less number of child parts.
c) Cost saving due to simple design and less number of assembly parts etc. no possibility of rejection during assembly.

In an embodiment, a hollow portion 144 is machined from top to bottom from within the metallic body may be having two steps cut within the hollow portion. One being a larger hollow portion 144 and other being a smaller hollow portion 145. In an example embodiment, the hollow portion 144 has a larger threaded portion 116 which may be located on upper side of the metallic part 102 and a smaller threaded portion 118 which may be located on the smaller hollow portion 145 or on lower side of the metallic part 102.

Thus, the present embodiment tries to achieve optimum sealing of the assembly over a longer period of time with minimal or no leakage possibility of any gas, thereby providing ideal sealing of the integration between the cylinder body and the Boss part with almost zero leakage of the gas from the composite cylinder.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope.