Title of Invention

A DEVICE USEFUL FOR SUPPORTING UNDERGROUND MINE TUNNELS, ROADWAYS.

Abstract

A device useful for supporting underground mine tunnels, roadways, which comprises a bottom tubular element (2) having external threads on the top portion, characterised in that the said threaded portion being provided with an openable holding clamp (4), on the said holding clamp (4) a helical spring (5) and a tubular spring holding element (3) being coaxially placed in the threaded top portion of the said bottom tubular element (2), the said bottom tubular element (2) being provided with a telescopically fitting top tubular externally threaded element (1), the said top tubular externally threaded element (1) having an openable holding clamp (7) and a lock nut (6) below it, the said lock nut (6) being placed touching the top of the said helical spring (5) inside the said tubular spring holding element (3) on the threaded top portion of the said bottom tubular element (2), twin jacks (8) being provided between the said openable holding clamps (4 & 7). (Fig-3)

Full Text

This invention relates to a device useful for supporting underground mine tunnels, roadways. The device of the present invention will find wide usage particularly for supporting underground mine tunnels, roadways. In general, underground mine tunnels, roadways are supported, specially in India, by using wooden cogs/props as support. But as wood is becoming scarce, there is need for suitable alternative supports to replace timbers in mines. Keeping in mind the Indian mining condition the support should be of greater longevity, light enough for easy portability and requiring less maintenance. Further, it should have facilities for height variation, sufficient yielding, continuous load monitoring and releasing remotely as the coal seam thickness widely varies in Indian mines. Then, the support material must be easily available and should have ease in operation by even an unskilled worker. Finally, the device must be economically viable for Indian mines, which is thriving for its longer life and should provide safety for miners. In this direction several efforts have been made as can be seen from a survey of the hitherto known prior art. Reference may be made to patent no. US 5,967,702 and CA2236062, wherein is described a pit prop having two opposed ends and comprising two bearing plates located at the ends, two telescopically displaceable prop elements, a number of separate resiliently compressible rubber discs arranged adjacent one another and a tubular indicating element. The prop includes a further bearing plate with the discs being located between two bearing plates to permit yielding of the pit prop under a load. The indicating element has markings thereon to indicate the load condition of the prop. The prop includes a locking device for releasably locking the prop elements with respect to one another. From the survey of hitherto known prior art it is seen that there is scope for improvement and hence there exists a definite need for providing a device useful for supporting underground mine tunnels, roadways. The main objective of the present invention is to provide a device useful for supporting underground mine tunnel, roadways, which obviates one or more of the drawbacks of the hitherto known prior art, as mentioned above. Another objective of the present invention is to provide a device useful for supporting underground mine tunnels, roadways, which will replace timber completely thus maintaining ecological balance. Yet another objective of the present invention is to provide a device useful for supporting underground mine tunnels, roadways, wherein no wedging is required. Still another objective of the present invention is to provide a device useful for supporting underground mine tunnels, roadways, wherein setting load can be provided. Still yet another objective of the present invention is to provide a device useful for supporting underground mine tunnels, roadways, wherein all the parts are detachable thus easily transportable, which can be easily installed and dismantled quickly. A further objective of the present invention is to provide a device useful for supporting underground mine tunnels, roadways wherein height variation can be possible. A still further objective of the present invention is to provide a device useful for supporting underground mine tunnels, roadways, which will provide yielding characteristic. Another objective of the present invention is to provide a device useful for supporting underground mine tunnels, roadways, wherein easy withdrawal is possible, even from a remote distance. Yet another objective of the present invention is to provide a device useful for supporting underground mine tunnels, roadways, which provides for continuous monitoring of roof load, thus avoiding a separate measuring instrument. Still another objective of the present invention is to provide a device useful for supporting underground mine tunnels, roadways, which is compact, robust and requires minimal maintenance, thus very cost effective and economically viable. In the present invention there is provided a device useful for supporting underground mine tunnels, roadways. The device of the present invention consists of an externally threaded top tubular element which is capable of being inserted telescopically into a bottom tubular element having external threads on the top portion. An openable holding clamp having internal threading matching the external threads of the bottom tubular element is provided for coaxially placing a helical spring and a tubular spring holding element on threaded part of the said bottom tubular element. The top tubular externally threaded element is provided with a lock nut having matching internal threads. The said lock nut is placed touching the top of the helical spring inside the tubular spring holding element on threaded part of the said bottom tubular element. On the top tubular element, above the said lock nut, another openable holding clamp having internal threading matching the external threads of the top tubular element is provided for holding twin jacks placed between the holding clamps, one clamp on the bottom tubular element and the other clamp on the top tubular element. The device of the present invention is described in figures 3, 4 and 5 of the drawings accompanying this specification. Figure 3 shows the schematic diagram of the device of the present invention in assembled condition. Figure 4A depicts the holding clamp in closed position and fig. 4B shows the holding clamp in open condition. Fig. 5 shows the helical spring fitted with pointer for convergence measurement of the prop. The various parts as shown in the above referred fig. 3, 4 and 5 of the drawings accompanying this specification are: (1) Top tubular externally threaded element. (2) Bottom tubular element having external threads on the top portion. (3) Tubular spring holding element. (4) Openable holding clamp having matching internal threading with the external threads on the top portion of the bottom tubular element (2). (5) Helical spring. (6) Lock nut. (7) Openable holding clamp having internal threading matching the external threads of the top tubular element (1). (8) Twin jacks. The above said parts in combination comprise the device of the present invention useful for supporting underground mine tunnels, roadways. Accordingly, the present invention provides a device useful for supporting underground mine tunnels, roadways, which comprises a bottom tubular element (2) having external threads on the top portion, characterised in that the said threaded portion being provided with an openable holding clamp (4), on the said holding clamp (4) a helical spring (5) and a tubular spring holding element (3) being coaxially placed in the threaded top portion of the said bottom tubular element (2), the said bottom tubular element (2) being provided with a telescopically fitting top tubular externally threaded element (1), the said top tubular externally threaded element (1) having an openable holding clamp (7) and a lock nut (6) below it, the said lock nut (6) being placed touching the top of the said helical spring (5) inside the said tubular spring holding element (3) on the threaded top portion of the said bottom tubular element (2), twin jacks (8) being provided between the said openable holding clamps (4 & 7). In an embodiment of the present invention the openable holding clamp (4) is having matching internal threading with the external threads on the top portion of the bottom tubular element (2). In another embodiment of the present invention the openable holding clamp (7) and lock nut (6) are both having internal threading matching the external threads of the top tubular element (1). In still another embodiment of the present invention the external and internal threadings are of same matching pitch. In yet another embodiment of the present invention the helical spring is fitted with a convergence measurement pointer. The novelty of the device of the present invention useful for supporting underground mine tunnels, roadways are that it is compact, is of robust construction which requires minimal maintenance, and hence is very cost effective, thus economically viable. It provides for continuous monitoring of convergence of the roof. Further, all the parts are detachable thus easily transportable, installation is very easy, dismantling is quick and it also provides height variation, setting load, yielding characteristic, ease of withdrawal even from a remote distance . The non-obvious inventive steps which enable the novelty of the device of the present invention comprise in combination the parts such as the top tubular externally threaded element, the bottom tubular element having external threads on the top portion, the helical spring, the tubular spring holding element, the lock nut, the open able holding clamps having matching internal threading and the twin jacks. The above said parts provide in combination the novel device of the present invention useful for supporting underground mine tunnels, roadways. In actual practice the operation of the device of the present invention useful for supporting underground mine tunnels, roadways, is as detailed below: The top tubular element (1), the bottom tubular element (2), the middle tubular element (3) along with helical spring (5), the lock nut (6) and both the clamps (4) and (7) along with twin jacks (8) can be separately transported to the site of support erection. The bottom structure (2) would be placed horizontally on the floor first. Then clamp (4) will be clamped on the outer periphery of the bottom tube on threads and the middle tube (3) along with helical spring (5) will be placed on the clamp (4). After that the top tube (1) along with lock nut (6) will be inserted in the bottom tube (2) then the other clamp (7) will be clamped on the top tube (1). Further, the whole device in combination, as herein above described, will be erected vertically so that it can touch the mine roof. Then twin jacks (8) will be placed between the two-clamps (4) and (7) and the pump of the twin jacks (8) will be operated to extend the ram of the jack for lifting up the tubular structure (1) against the roof. When the induced load to the tubular structure (1) will be around 5 tonne, the lock nut (6) will be tightened against the spring (5). Once the prop is set, the jacks (8) along with the top clamp (7) will be withdrawn from the site. During loading, the load will come through the top tube (1) to the helical spring (5) through lock nut (6) and then transmit to the bottom tube(2) through the holding clamp(4). As the load increases, the spring will be compressed, which in turn facilitates the yielding of the prop. During withdrawal, the holding clamp(4) will be opened from a safe distance by rotating the nut We claim: 1. A device useful for supporting underground mine tunnels, roadways, which comprises a bottom tubular element (2) having external threads on the top portion, characterised in that the said threaded portion being provided with an openable holding clamp (4), on the said holding clamp (4) a helical spring (5) and a tubular spring holding element (3) being coaxially placed in the threaded top portion of the said bottom tubular element (2), the said bottom tubular element (2) being provided with a telescopically fitting top tubular externally threaded element (1), the said top tubular externally threaded element (1) having an openable holding clamp (7) and a lock nut (6) below it, the said lock nut (6) being placed touching the top of the said helical spring (5) inside the said tubular spring holding element (3) on the threaded top portion of the said bottom tubular element (2), twin jacks (8) being provided between the said openable holding clamps (4 & 7). 2. A device as claimed in claim 1, wherein the openable holding clamp (4) is having matching internal threading with the external threads on the top portion of the bottom tubular element (2). 3. A device as claimed in claim 1, wherein the openable holding clamp (7) and lock nut (6) are both having internal threading matching the external threads of the top tubular element (1). 4. A device as claimed in claims 1-3, wherein the external and internal threadings are of same matching pitch. 5. A device as claimed in claims 1-4, wherein the helical spring is fitted with a convergence measurement pointer. 6. A device useful for supporting underground mine tunnels, roadways, substantially as herein described with reference to figures 3 to 5 of the drawings accompanying this specification.

Documents:

1026-del-2004-Abstract-(24-12-2009).pdf

1026-DEL-2004-Abstract-(27-04-2010).pdf

1026-del-2004-abstract.pdf

1026-del-2004-Claims-(24-12-2009).pdf

1026-DEL-2004-Claims-(27-04-2010).pdf

1026-del-2004-claims.pdf

1026-del-2004-corresoindence.pdf

1026-del-2004-Correspondence-Others-(24-12-2009).pdf

1026-DEL-2004-Correspondence-Others-(27-04-2010).pdf

1026-del-2004-Description (Complete)-(24-12-2009).pdf

1026-DEL-2004-Description (Complete)-(27-04-2010).pdf

1026-del-2004-description.pdf

1026-del-2004-drawings.pdf

1026-del-2004-Form-1-(24-12-2009).pdf

1026-DEL-2004-Form-1-(27-04-2010).pdf

1026-DEL-2004-Form-2-(27-04-2010).pdf

1026-del-2004-Form-3-(24-12-2009).pdf

1026-del-2004-form1.pdf

1026-del-2004-form2.pdf

1026-del-2004-form3.pdf

1026-del-2004-form5.pdf