Title of Invention

AN IMPROVED COG USEFUL FOR SUPPORTING UNDERGROUND MINE ROOFS/TUNNELS

Abstract An improved cog useful for supporting underground mine roofs/tunnels, which comprises one or more vertical column(s) (3,5) extendible by means (4) such as a collar, characterised in that the bottom of the column (5) being provided with a base frame (6) having an adjustable vice arrangement (7,8) for holding the bottom portion of the said column (5), the said column pipe (5) being provided with a removably fixed hydraulic jack (9, 10) for providing vertical thrust to the said column(s) (3,5), the top of the said column (3) being provided with a crown (2) having a platen for holding the wooden sleeper(s) (l).
Full Text This invention relates to an improved cog useful for supporting underground mine roof/tunnels.
The present invention is an improvement of our patent application no. 1867/DEL/97. The said patent application no. 1867/DEL/97 is the main invention and the present patent application is a patent of addition, as it incorporates modification of the main patent application.
In underground mines, supporting of roofs is a very crucial factor and the mines need different types of supports for different purposes. In depillaring of coal pillars i.e. in the final extraction process they need a support of larger cross section (approx. 1m) which is generally fabricated by wooden sleepers of 1.2 length and 5" x 5" cross section. These sleepers are laid cross wise alternatively in a square from upto the roof height. These are called cogs (or Timber cogs).
Wooden cogs take much time to be installed and also while being withdrawn. These supports are necessary at the vulnerable places of underground panels like goafedges, slices and junctions. These wooden supports have drawbacks that:
1. It is cumbersome and time taking to erect/install.
2. It is not possible to withdraw the support from a distance, one has to
move near the support to dismantle it.
3. The supporting capacity is less.
4. Life of the cog support is also less as the life of woods in mines is short
due to water and moisture.

5. Cannot provide any setting load to the roof.
There are some steel cogs available, which are generally made of steel angles/channels/square hollow sections/tubes etc.
Reference may be made to Indian Patent application no. 1006/CAL/1988 (Patent no. 170926) of the Tata Iron & Steel Co. Ltd.
It is made of square hollow sections welded together to make a cube form of 1m x 1m x 1m size. This 1m cube form of blocks are set together (generally 3 nos.) one above another to make a height of 3m in the mines to support the roof. This one cubic meter block of square hollow tube is called TISCOG.
Reference may also be made to our Indian Patent application no. 854/DEL/89.
The device is a quick setting chock for supporting the roofs of underground mines. It is made of 4 long pipes of 3m height having top cover and bottom plate made of steel angles welded together form (1m x 1m). The 4 steel tubes are cross wise connected by two holder pieces. Some of the major disadvantages of these steel cogs are:
Both the above referred cogs are rigid and fixed type, heavy to carry in underground, not suitable for very long height of working. These cannot provide any setting load against the roof and floor. They also take time to install in underground mines/tunnels. These are not suitable for variable height adjustment and also need manual presence while withdrawing the steel cogs at the working site.

In our main invention vide Indian Patent application no. 1867/DEL/97 we have described and claimed an improved cog useful for supporting underground mine roofs/tunnels. The schematic of the device is shown in fig.1 of the drawings accompanying this specification.
In Figure- 1 of the drawings accompanying this specification the schematic diagram of the improved cog as described and claimed in our patent application no. 1867/Del/97 is shown. The various components are an extendible tubular structure with a crown at the top capable of holding wooden sleeper and a base frame and mechanism for holding the main tube. A removal hydraulic jacking arrangement is incorporated for providing setting load.
Accordingly, the main invention in our patent application no. 1867/Del/97 provides an improved cog useful for supporting underground mine roofs/ tunnels, which comprises one or more vertical column (s) (3,5) extendible by means (4) such as a collar, the bottom of the column (5) being provided with a base frame (6) having an adjustable vice arrangement (7,8) capable of holding the bottom portion of the said column (5), the said frame (6) being provided with a removable hydraulic jack (9,10) capable of providing vertical thrust to the column(s) (3,5), the top of the said column (3) being provided with a crown (2) having a platen for holding the wooden sleeper(s) (1).
The main invention incorporates an improvement in the support technology in wide-open areas in underground mines / tunnels. The sensitive zones, which need heavy and taller support, can be properly

supported by this device of the present invention. Provision of support covering a large area can be executed very quickly.
The operation of the improved cog of the main invention is detailed below:
The top structure (2), the columns (3,5) and bottom structure (6) can be separately transported to the site of support erection. The bottom support (6) would be placed horizontally first and the column (5) and (3) would be fixed by means of collar (4) and placed accordingly. Then, the top frame (2) would be fixed with the top of column (3). The structure would be erected vertically up. Then wooden sleepers would be placed on the top platen of the crown (2) to adjust the height as necessary to touch the mine roof. The jack (9) would be placed below the column (5) fitted into base frame (6). Then the pump will be operated to lift the ram of jack for lifting up the columns (3,5) and crown (2) against the roof. When, the induced load by the to the columns and crown would be around 10 tonne, the screw(s) (8) of adjustable vice arrangement (7) will be operated to hold the bottom column (5) in position. Once the cog is set, the jack is withdrawn from the site. At the time of releasing load, the screw (8) of the vice arrangement (7) is operated in opposite direction to get the holder halves separated apart and thus allowing the columns (3,5) and crown (2) to come down lower and whole thing gets released. Thereafter, the steel cog can be remotely withdrawn once the load is released.

But the above device has got a limitation for which it may not suit all the requirements of some difficult mines. Important one is that it can not yield under overload, it is a rigid system of support. The quality of getting yielded under overload is an important criterion for support in some mines under geo-miriing conditions and method of working. Provision of setting load at the time of installation and yielding under overload may add to improved version of support for underground mines.
The main object of the present invention is to provide a modification and/or improvement to the device as described and claimed in our main invention vide patent application no. 1867/DEL/97.
Another object is to provide an improved chock suitable for quick
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setting mechanism, variables height adjustment, higher capacity, easy and quick installation, setting load at the time of installation, having remote withdrawal mechanism and providing yielding capability under overload which is an improvement of the device of our main invention vide patent application no. 1867/DEL/97.
In Figure- 2 of the drawings accompanying this specification the schematic diagram of the improved chock of the present invention is shown. The various components are an extendible tubular structure with a pyramidal crown at the top capable of holding wooden sleeper and a inverted pyramidal base frame and mechanism for holding the main tube. A fixed hydraulic jack arrangement is incorporated in the tubular portion for providing setting load and yielding of the same under overload.

Accordingly, the present invention provides an improved cog useful for supporting underground mine roofs/tunnels, which comprises one or more vertical column(s) (3,5) extendible by means (4) such as a collar, characterised in that the bottom of the column (5) being provided with a base frame (6) having an adjustable vice arrangement (7,8) for holding the bottom portion of the said column (5), the said column pipe (5) being provided with a removably fixed hydraulic jack (9, 10) for providing vertical thrust to the said column(s) (3,5), the top of the said column (3) being provided with a crown (2) having a platen for holding the wooden sleeper(s) (1).
In an embodiment of the present invention the hydraulic jack (9) used is a known yieldable hydraulic device.
In another embodiment of the present invention the hydraulic jack (9) is provided with a detachably fixed pump (10).
The present invention incorporates an improvement in the support technology in wide-open areas in underground mines / tunnels. The sensitive zones, which need heavy and taller support, can be properly supported by this device of the present invention. Provision of support covering a large area can be executed very quickly. The removably fixed hydraulic jack (9) is an yieldable hydraulic device which yields at a pre-set load, having a special valve block. It starts yielding while a certain load (which is fixed earlier by the operator) reaches on the support and immediately stops when there is a less of load than the fixed yielding load. The valve, which is used here as the incharge valve, can be used for withdrawal of the prop. The same valve can be discharged with the help of

a key and can be operated remotely from a distance. Therefore, the incorporation of a hydraulic jack (9) in the column itself is novel which facilitates to set the prop with (a) setting load, (b) yielding capability (c) remote setting device, (d) remote withdrawal device and (e) height variance.
The operation of the improved cog of the present invention is detailed below:
The top reverse pyramidal structure (2), the central vertical column(s) (3,5) extendible by means (4) such as a collar and bottom pyramidal base structure (6) of the device can be separately transported to the site of support erection. The bottom structure (6) would be placed horizontally first and the central vertical column(s) (3,5) would be fixed flexibly and placed accordingly. Then the top reverse pyramidal structure (2) would be fixed flexibly with the top of central vertical column(s) (3,5) in horizontal condition. The device would be lifted vertically up. Then wooden sleepers may be placed on the top platen of the structure (1) to adjust the height as necessary to touch the mine roof. Then the pump (10) of the hydraulic jack (9), which is placed in between the tubular parts (3,5), will be operated to extend the ram of the jack for lifting up the column (3) and the top structure (2) against the roof, till the induced load by the jack to the column and the top structure would be around 5 tons to set the chock. In case of overloading, the chock would be yielded due to yielding capacity of the jack (9). At the time of releasing the support, the valve of the pump will be opened from a safe distance and thus allowing the column (3) along

with the top structure (2) to come down lower and whole thing gets released. Thereafter, the chock can be remotely withdrawn once the load is released.
The main advantages of the improved cog of the present invention are:
1. It is dismantalable quickly.
2. It is installable quickly.
3. Members are light to carry.
4. It can provide high axial load bearing capacity.
5. Its having yielding capacity under overload.
6. It is suitable for higher height of underground working / extraction.
7. It is having facility of variable height adjustment.
8. It can provide considerable setting load against roof.
9. It can be released easily and remotely.
10. It is easily repairable and hence maintenance cost is least and running
cost is almost nil.
11. It replaces timber supports and thus environment friendly.
12. Life span of this support is quite high.
13. Economically viable.



We claim:
1. An improved cog useful for supporting underground mine roofs/tunnels, which
comprises one or more vertical column(s) (3,5) extendible by means (4) such as a
collar, characterised in that the bottom of the column (5) being provided with a base
frame (6) having an adjustable vice arrangement (7,8) for holding the bottom
portion of the said column (5), the said column pipe (5) being provided with a
removably fixed hydraulic jack (9, 10) for providing vertical thrust to the said
column(s) (3,5), the top of the said column (3) being provided with a crown (2)
having a platen for holding the wooden sleeper(s) (1).
2. An improved cog as claimed in claim 1, wherein the hydraulic jack (9) used is a
known yieldable hydraulic device.
3. An improved cog as claimed in claim 1,2, wherein, the hydraulic jack (9) is
provided with a detachably fixed pump (10).
4. An improved cog useful for supporting underground mine roofs / tunnels,
substantially as herein described with reference to Fig. 2 of the drawings
accompanying this specification.

Documents:

1088-del-2001-abstract.pdf

1088-del-2001-claims.pdf

1088-del-2001-correspondence-others.pdf

1088-del-2001-correspondence-po.pdf

1088-del-2001-description (complete).pdf

1088-del-2001-drawings.pdf

1088-del-2001-form-1.pdf

1088-del-2001-form-18.pdf

1088-del-2001-form-2.pdf

1088-del-2001-form-3.pdf


Patent Number 242288
Indian Patent Application Number 1088/DEL/2001
PG Journal Number 35/2010
Publication Date 27-Aug-2010
Grant Date 20-Aug-2010
Date of Filing 30-Oct-2001
Name of Patentee COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH,
Applicant Address RAFI MARG, NEW DELHI-110001, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 DR. SIBNATH MAITY CENTRAL MINING RESEARCH INSTITUTE, BARWA ROAD, DAHNBAD, JHARKHAND.
2 SHANKAR PRASAD CENTRAL MINING RESEARCH INSTITUTE, BARWA ROAD, DAHNBAD, JHARKHAND.
3 SUBHASHISH TEWARI CENTRAL MINING RESEARCH INSTITUTE, BARWA ROAD, DAHNBAD, JHARKHAND.
PCT International Classification Number E21D 15/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA