DESC:FIELD OF THE INVENTION
This invention relates generally to chain conveyors and particularly to designing and manufacturing of industrial chains.

BACKGROUND OF THE INVENTION
Conveyors are used for transporting materials in most industries. Typically, conveyors are formed by joining multiple chain-links to form an endless or continuous chain. Such chains are used as drives elevators or conveyors in pairs, running in parallel. The material to be conveyed is placed on the chains.
Accordingly, a conveyor chain consists of multiple chain-links and pins which are produced separately and assembled together to form long endless chain strand, which is mounted on a track and driven and guided by wheels. In most of the cases, the pin is permanently fixed. The method of forming such conveyor chains involves mechanically locking pin at ends so that the pin does not come out during operation. This type of chain is generally known as fixed pin or riveted pin chain. The limitations of this design during installation, periodic changeover, maintenance operations, and replacement in part lengths include lack of flexibility in fixed pin linkages while operation, need of specialized tools for removal and refitting, and postural limitation to use tool in changeover. Other limitations include site riveting of the pin cannot be alike factory fitting, therefore may result in improper fitting, leaving the chance of loosening/coming out. All above results in loss of time & incurring costs.
Further, the use of chain conveyors in liquid petroleum gas (LPG) refilling industries, where such chains are used to convey filled and empty bottles of LPG, causes another set of issues. The conveying chains used in refilling plants use links manufactured from carbon steel which when moved/traveled over steel tracks creates frictional forces because of steel on steel travel. Soap water is used as a lubricant and as a deterrent for possible static charge generation by friction. The use of soap water lubricants leaves plant dirty, wet, water spilled and increases the possibility of an accident because of such floor conditions. The use of stale water or unchanged water may create an odor. If lubricants are not used or are used inadequately or if the lubricants do not reach the desired area, friction increases and the possibility of static charge in the area which is unsafe in explosive environment also increases.
Hence, there is a need for a conveyor chain which overcomes the limitation of a fixed pin chain and eliminates the limitations of lubricants in LPG refilling industries. The chain must also provide easy removal and fitting of chain-link and pin without using specialized tools, and should also save time in maintenance, thus reducing plant downtime, in turn improving the productivity of the plant.

SUMMARY OF THE INVENTION
The objective of the present invention is to provide a chain, a chain-link, and a method to form the chain.
In an embodiment of the present invention, a chain is provided. The chain includes a plurality of chain-links and pins. Each chain-link has first and second flanges and a neck portion. The first and second flanges have first and second elliptical holes, respectively, at outer ends. The neck portion joins other ends of the first and second flanges such that the first and second flanges are separated by a predetermined distance and the first and second elliptical holes are centrally aligned. The neck portion has a third elliptical hole. A pin, having a predefined shape, removably passes through first and second elliptical holes of a chain-link and through a third elliptical hole of adjacent chain-link between the first and second holes of the chain-link only when the chain-link and the adjacent chain-link are at a predetermined angle for forming a hole of the predefined shape of the pin. The pin connects the two chain-links to form the chain.
In another embodiment of the present invention, a chain-link is provided. The chain-link includes first and second flanges and a neck portion. The first and second flanges have first and second elliptical holes at outer ends. The neck portion joins other ends of the first and second flanges such that the outer ends of the first and second flanges are separated by a predetermined distance and the first and second elliptical holes are centrally aligned. The neck portion has a third elliptical hole at a predetermined angle with the first and second elliptical holes. Alternatively, the elliptical hole on the neck portion and flanges can have same orientation.
In yet another embodiment of the present invention, a method of forming a chain is provided. The method includes providing a plurality of chain-links, providing a plurality of pins having a predefined shape, placing a chain-link at a predetermined angle with an adjacent chain-link such that a neck portion of the second chain-link is between two flanges of the first chain-link, and an elliptical hole of the neck portion of the second chain-link is centrally aligned with two elliptical holes of the two flanges of the first chain-link for forming a hole of predefined shape of the pin. The method further includes inserting the pin through the two elliptical holes of the two flanges of the chain-link and the elliptical hole of the neck portion of the adjacent chain-link. The method further includes rotating the chain to linearly align the second chain-link with the first chain-link, thereby continuing and connecting the chain-links to form a chain.

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 is understood that it is not intended to limit the scope of the invention to these particular embodiments:
Figure 1 shows a chain in accordance with an embodiment of the present invention; and
Figures 2-5 show a design of a chain in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
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. It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
In general, the present invention provides a chain, a chain-link, and a method to form a chain. The chain can be endless or continuous.
In an embodiment of the present invention, a chain is provided. The chain includes a plurality of chain-links and pins. Each chain-link has first and second flanges and a neck portion. The first and second flanges have first and second elliptical holes, respectively, at outer ends. The neck portion joins other ends of the first and second flanges such that the first and second flanges are separated by a predetermined distance and the first and second elliptical holes are centrally aligned. The neck portion has a third elliptical hole. A pin passes through first and second elliptical holes of a chain-link and through a third elliptical hole of adjacent chain-link when the two chain-links are at a predetermined angle. The pin connects the two chain-links to form the chain.
In an example, the third elliptical hole is at the predetermined angle with respect to the first and second elliptical holes. The predetermined angle is 45 degrees to 135 degrees. Preferably, the predetermined angle is 90 degrees.
In an example, the second elliptical hole is smaller than the first elliptical hole. Therefore, the pin passes through the first elliptical hole into the second elliptical hole and not otherwise such that the pin can be inserted and removed only through the first elliptical hole.
Alternatively, third elliptical hole and the first and second elliptical holes have similar orientation and the adjacent chain-links have with a predetermined angle. In an example, a chain-link has elliptical holes on flanges and neck potion in horizontal direction and adjacent chain-links i.e. front and back chain-links have elliptical holes in vertical direction.
In an example, the pin passes through the first elliptical hole into the third elliptical hole only when the two chain-links are at the predetermined angle.
In an example, the pin is cylindrical in shape and is narrower at edges and broader in central portion. Advantageously, the pin can have any cross sectional shape including oval, elliptical, polygonal cross-section depending upon the shape of the holes provided on the chain link.
In an example, the two chain-links are rotated to be linearly aligned after inserting the pin.
In another embodiment of the present invention, a chain-link is provided. The chain-link includes first and second flanges and a neck portion. The first and second flanges have first and second elliptical holes at outer ends. The neck portion joins other ends of the first and second flanges such that the outer ends of the first and second flanges are separated by a predetermined distance and the first and second elliptical holes are centrally aligned. The neck portion has a third elliptical hole at a predetermined angle with the first and second elliptical holes.
In yet another embodiment of the present invention, a method of forming the chain is provided. The method includes placing a chain-link at a predetermined angle with an adjacent chain-link such that a neck portion of the second chain-link is between two flanges of the first chain-link, and an elliptical hole of the neck portion of the second chain-link is centrally aligned with two elliptical holes of the two flanges of the chain-link. The method further includes inserting the pin through the two elliptical holes of the two flanges of the first chain-link and the elliptical hole of the neck portion of the adjacent chain-link. The method further includes rotating the chain to linearly align the adjacent chain-link with the first chain-link, thereby connecting the chain-links to form the chain.
Referring Figure 1 shows a chain (1000) in accordance with an embodiment of the present invention.
The step 1 of the Figure 1 depicts first and second chain-links (100 and 200) of the chain (100).
The first chain-link (100) includes first and second flanges (102a and 102b). For simplicity, the first and second flanges (102a and 102b) are collectively labelled as the flanges (102), as shown in Figure 1. The first chain-link (100) further includes a neck portion (104). The first and second flanges (102a and 102b) have first and second elliptical holes (106a and 106b). For simplicity, the first and second elliptical holes (106a and 106b) are collectively labelled as the elliptical holes (106), as shown in Figure 1. The neck portion (104) of the first chain-link (100) includes a third elliptical hole (108).
The neck portion (104) joins the first and second flanges (102a and 102b) at one end such that the first and second flanges (102a and 102b) are at a predetermined distance and the first and second elliptical holes (106a and 106b) are centrally aligned. The predetermined distance between the two flanges of the chain-link is little greater than the width of the neck portion so that it can allow easy insert and movement of the neck portion of the adjacent chain-link for forming a chain. Obviously, a person skilled in the art may, without any creative effort, can easily found the predetermined distance between the flanges.
The second chain-link (200) includes first and second flanges (202a and 202b). For simplicity, the first and second flanges (202a and 202b) are collectively labelled as the flanges (202), as shown in Figure 1. The second chain-link (200) further includes a neck portion (204). The first and second flanges (202a and 202b) have first and second elliptical holes (206a and 206b). For simplicity, the first and second elliptical holes (206a and 106b) are collectively labelled as the elliptical holes (206), as shown in Figure 1. The neck portion (204) of the first chain-link (200) includes a third elliptical hole (208).
The neck portion (204) joins the first and second flanges (202a and 202b) at one end such that the first and second flanges (202a and 202b) are at a predetermined distance and the first and second elliptical holes (206a and 206b) are centrally aligned.
In a preferable example, the first and second chain-links (100 and 200) are structurally and functionally similar.
The step 2 of the Figure 1 depicts that the second chain-link (200) is placed at a predetermined angle with the first chin link (100) such that the first and second elliptical holes (106a and 106b) of the first chain-link (100) are centrally aligned with the third elliptical hole (208) of the second chain-link (200).
The first and second elliptical holes (106a and 106b) are at the predetermined angle with respect to the third elliptical hole (208). In a preferable embodiment, the predetermined angle is between 45 degrees and 135 degrees. In an exemplary embodiment, the predetermined angle is 90 degrees. Therefore, when the first and second chain-links (100 and 200) are held at the predetermined angle of 90 degrees as shown in step 2 of Figure 1, the first and second elliptical holes (106a and 106b) coincide with the third elliptical hole (208) to form a through-hole of a predetermined shape and size substantially same to that of the pin to be inserted for allowing easy insert and removal of the pin at the predetermined angle.
In an example, cross-sectional area of the second elliptical hole (106b) is lesser than cross-sectional area of the first elliptical hole (106a), i.e., the second elliptical hole (106b) is smaller than the first elliptical hole (106a).
The step 2 of the Figure 1 further depicts a pin (300) having a narrow upper end (302) and a narrow lower end (304). In an example, central portion of the pin (300) is broad and cylindrical in shape. However, the pin (300) may have a circular, oval, or elliptical cross-section.
The step 3 of the Figure 1 depicts that the pin (300) is inserted through the first elliptical hole (106a), which is the larger sized hole. The pin (300) passes through the third elliptical hole (208) and into the second elliptical hole (106b) which is the smaller sized hole.
In an example, the shape and size of the through-hole, formed by the central alignment of the first and second elliptical holes (106a and 106b) with the third elliptical hole (208), is same as the shape and size of the cross-section of central portion of the pin (300), thereby enabling the pin (300) to slide through the through-hole formed by the elliptical holes at the predetermined angle.
The first and second elliptical holes (106a and 106b) are proportioned with respect to cross-sectional area of the pin (300) in such a way that the first elliptical hole (106a) is adequately big for quick and easy location and entry or removal of the pin (300). The cross-sectional area of the second elliptical hole (106b) is inadequate for the central portion of the pin (300) to exit through, but is adequate for entry and location of the lower end (304) of the pin (300).
Therefore, the pin (300) can be entered and removed only through the first elliptical hole (106a) which is the larger sized hole and not through the second elliptical hole (106b) which is the smaller sized hole.
In an example, the first and second elliptical holes (106a and 106b) are proportioned between 15-20% of the cross-sectional area of the central portion of the pin (300), for easy entry from the first elliptical hole (106a) and for prevention of exit from the second elliptical hole (106b). This ensures interlocking of the first and second chain-links (100 and 200).
The design of the first and second chain-links (100 and 200) ensures easy movement of the chain (1000) over curvatures, bends and over “S” shaped tracks. The design also ensures that the pin (300) does not come out while moving over aforementioned tracks.
During removal of the pin (300), the second chain-link (200) is rotated to form the predetermined angle with the first chain-link (100), as depicted in step 3 of the Figure 1. The pin is thereafter removed by pushing the pin (300) out of the first elliptical hole (106a).
Thereafter, as depicted in step 4 of the Figure 1, the second chain-link (200) is rotated be linearly aligned with the first chain-link (100). After the first and second chain-links (100 and 200) are linearly aligned, the pin (300) connects the first and second chain-links (100 and 200) to form the chain (1000). The chain (1000) is easily extendable by connecting one or more chain-links to the existing chain-links. The chain-links can be extended to form a long open-ended chain or the first and last chain-links can be connected to form a chain loop, depending on the application of the chain (1000).
Further, the Figure 1 also depicts the chain (1000) extended by connecting two more chain-links to the second chain-link (200).
Referring Figures 2-5 show exemplary designs of the chain (1000) in accordance with an exemplary embodiment of the present invention. The chain (1000) is formed by multiple chain-links, including the first and second chain-links (100 and 200). The first and second chain-links are structurally and functionally same and are functionally replaceable.
The pin (300) is inserted through the first elliptical hole (206a) of the second chain-link (200) and the third elliptical hole (108) of the first chain-link (100) into the second elliptical hole (206b) of the second chain-link (200).
As shown in the referring Figures 2-5, the first to third elliptical holes (106a, 106b, 108, 206a, 206b, and 208) of the first and second chain-links (100 and 200) may have varied shapes, such as, but not limited to, oval, elliptical, and circular. Further, the pin (300) may have varied shapes, and is not limited to circular, oval, and elliptical shapes.
Advantageously, the chain (1000) of the present invention gives more flexibility as there is no need to change existing setup. The chain (1000) can fit right into the existing setup making it easier for users to immediately shift to a more user-friendly and safer chain. The other advantages include easy removal and fitting of the chain-links and pins without using sophisticated tools, secure locking of the chain, one side removal of pins avoids accidents because of the pin coming out, and no need to use lubricated solutions which mean cleaner shop floor with lesser maintenance. Overall, the chain (1000) saves time of maintenance, thus reducing plant downtime, in turn improving the productivity of the plant.
The chain (1000) is used where riveted chains are typically used along with lubricated solutions like critical environments like LPG refilling plants where safety is an utmost priority and in long haul conveyor systems where changing the chain length is difficult and time-consuming.
The chain (1000) of the present invention possesses user-friendly design leading to less fatigue/stress to users. No hammering as well as skilled worker is required for changing the chain-link of the chain (1000), which eliminates potential sparking. Moreover, there is no need to use lubricated solutions when the chain (1000) is made of ductile iron, which means cleaner shop floor, less maintenance required. Moreover, it is possible to separate all chain-links and pin easily.
The chain (1000) can be used safely where riveted chains are typically used along with lubricated solutions, such as in inflammable environment like LPG Bottling plants where safety is the utmost priority.
Further advantageously, the chain (1000) operates with sprocket wheels in elevators or conveyors or is incorporated in a simple and inexpensive apparatus which employs chains and which provides easy removal and fitting of chain-links and pins without using specialized tools. The chain (1000) is of novel and improved material grade, process and installation, which is friendly to explosive environment and eliminates wet working. The chain-links are manufactured from ductile iron by a casting process which has high strength under normal and impacts loading conditions. Each chain-link is cast by a process of manufacture and single piece which imparts high strength in breaking load testing.
The chain (1000) is also a highly versatile and articulate chain. Hence, the chain (1000) of the present invention overcomes the drawbacks faced by the prior-art chains.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention.
Many modifications such as shape of the chain-links, pings, various shapes of the elliptical holes as well as neck portions and flanges may be made without departing from the basics of the present invention. Accordingly, it will be appreciated by those skilled in the art that the invention may be practiced other than has been specifically described herein.
Further, it will be apparent to one of the ordinary skill in the art that many modifications, improvements, and sub-combinations of the various embodiments, adaptations and variations can be made to the invention without departing from the scope thereof as claimed in the following claims:
,CLAIMS:
1. A chain comprising:
a plurality of chain-links, each chain-link having:
first and second flanges having first and second elliptical holes, respectively, at outer ends thereof; and
a neck portion joining other ends of the first and second flanges such that the outer ends of the first and second flanges are separated by a predetermined distance and the first and second elliptical holes are centrally aligned, said neck portion having a third elliptical hole; and
a plurality of pins having a predefined shape, each pin removably passing through first and second elliptical holes of a chain-link and through a third elliptical hole of adjacent chain-link between the first and second holes of the chain-link only when the chain-link and the adjacent chain-link are at a predetermined angle for forming a hole of the predefined shape of the pin, thereby connecting the two chain-links to form the chain.

2. The chain as claimed in claim 1, wherein the third elliptical hole is at the predetermined angle with respect to the first and second elliptical holes.

3. The chain as claimed in claim 1 or 2, wherein the second elliptical hole is smaller than the first elliptical hole.

4. The chain as claimed in one of the preceding claims 1-3, wherein the predetermined angle is preferably between 45 degrees and 135 degrees.

5. The chain as claimed in one of the preceding claims 1-4, wherein the pin is narrower at edges and broader in central portion.

6. The chain as claimed in one of the preceding claims 1-4, wherein the predefined shape of the pin includes a circular, oval, or elliptical cross-section.

7. A chain-link, comprising:
first and second flanges having first and second elliptical holes, respectively, at outer ends thereof; and
a neck portion joining other ends of the first and second flanges such that the outer ends of the first and second flanges are separated by a predetermined distance and the first and second elliptical holes are centrally aligned, said neck portion having a third elliptical hole at a predetermined angle with the first and second elliptical holes.

8. The chain-link as claimed in claims 7, wherein the predetermined angle is preferably between 45 degrees and 135 degrees.

9. A method of forming a chain as claimed in claim 1, the method comprising:
providing a plurality of chain-links as claimed in one of the claims 7-8;
providing a plurality of pins having a predefined shape;
placing a chain-link at a predetermined angle with an adjacent chain by inserting a neck portion of the adjacent chain-link is between two flanges of the chain-link, and aligning an elliptical hole of the neck portion of the adjacent chain-link with the elliptical holes of the two flanges of the chain-link to form a hole of the predefined shape of the pin;
inserting the pin through the two elliptical holes of the two flanges of the first chain-link and the elliptical hole of the neck portion of the second chain-link; and
rotating the adjacent chain-link to linearly align the second chain-link with the first chain-link, thereby continuing and connecting the chain-links to form a chain.

10. The method as claimed in claims 9, wherein the predetermined angle is preferably between 45 degrees and 135 degrees.