Title of Invention	"AN IMPROVED ROOF BOLT USEFUL FOR SUPPORTING MINE/TUNNEL ROOFS INSTANTLY AND COMPACTLY."
Abstract	An improved roof bolt useful for supporting mine/tunnel roofs instantly and compactly, which comprises a bolt rod having a threaded portion , the said threaded end being provided with means such as a plate with hole and a nut, the other end of the said bolt rod being characterized in that having an outwardly flaring conical bulged head , the said bulged head being provided with a matching flexible crown cap , the said crown cap being provided on its outer periphery with downward teeth , the said bolt rod having a plurality of flexible tubular sections throughout its length in between the said plate and the head .

Title of Invention

"AN IMPROVED ROOF BOLT USEFUL FOR SUPPORTING MINE/TUNNEL ROOFS INSTANTLY AND COMPACTLY."

Abstract

An improved roof bolt useful for supporting mine/tunnel roofs instantly and compactly, which comprises a bolt rod having a threaded portion , the said threaded end being provided with means such as a plate with hole and a nut, the other end of the said bolt rod being characterized in that having an outwardly flaring conical bulged head , the said bulged head being provided with a matching flexible crown cap , the said crown cap being provided on its outer periphery with downward teeth , the said bolt rod having a plurality of flexible tubular sections throughout its length in between the said plate and the head .

Full Text	This invention relates to an improved roof bolt useful for supporting mine/tunnel roofs instantly and compactly. In underground mines providing roof support is of utmost importance primarily to avoid roof collapse. The underground mines generally produce minerals by making tunnels. Therefore, thousands of kilometers of tunnels are to be maintained for travelling and conveying purposes in mines. Mine openings/tunnels require supporting properly to avoid accidents which occurs due to fall of roofs. There are direct supporting by vertical pieces of support and other indirect supports are roof bolts which actually increase the inherent bonding strength of roof, rather makeing the roof self supported. Roof bolting generally involves inserting steel bolts within the holes drilled in the roof rocks and holding the same by means. There are two types of roof bolts generally available in the mining field. The first is point anchored type being fixed at the top point either by mechanical method or by using an organic resin capsule with a roof bolt. The second one is full grouted bolt where the hole is filled with cement slurry or any cement grout mixture. The limitation of the point anchored roof bolts is that it can not provide sufficient anchorage strength if the rock of very point is not competent enough, though it can provide ten-sional force to the lower layers of rock by tightening the plate on roof surface and it is possible to place it instantly. The drawbacks of the full grouted roof bolt is that it can not provide the anchorage strength immediately and the process is time taking. In case of withdrawing the bolts from the fallen roof it is also not possible to take out the bolts as it is cemented with the broken lump. It Is also not possible to provide sufficient tension to the plate as the bolt is fully grouted. Therefore, there is a definite need for a roof bolt which can be instantly fixed onto the mine/tunnel roof and also provide compaction with the side walls by increasing frictional force in between,thus providing a more powerful anchorage strength. The main object of the present invention is to provide an improved roof bolt useful for supporting mine/tunnel roofs, which obviates the above noted drawbacks of the hitherto known roof bolts. Another object of this invention Is to provide an improved roof bolt which will be supporting the mine roof Instantly and also filling the drill hole compactly. The Figures - 1, 2 & 3 of the drawing accompanying this specification shows the schematic diagram of the device of the present invention. The various components are a bolt(3) with conical bulged head(2)and threaded(7) at lower portion, a plate(4), a nut (5), a metallic inverted U-Section semi round piece (1) having teeth on outer sides, some pieces of rubber tubes (6) having central holes. Accordingly, the present invention provides an improved roof bolt useful for supporting mine/tunnel roofs instantly and compactly, which comprises a bolt rod (3) having a threaded portion(7) , the said threaded end being provided with means (4,5) such as a plate (4) with a hole (9) and a nut (5), the other end of the said bolt rod being characterized in that having an outwardly flaring conical bulged head (2) , the said bulged head (2) being provided with a matching flexible crown cap (1), the said crown cap (1) being provided on its outer periphery with downward teeth (8), the said bolt rod (3) having a plurality of flexible tubular sections (6) throughout its length in between the said plate (4) and head (2). The operation of the device of the present invention is as follows : The flexible tubular sections(6) such as rubber tubing pieces are pushed in the rod of the bolt (3) in between the head (2) and the plate (4) supported by the nut (5). The bolt is then pushed into an hole drilled in the rock of mines roof keeping the head of bolt on the top side. When the head reaches the end of the hole, the rod is pulled back against the round rubber pieces and the plate. As the larger diameter head comes down, the crown flap (1) expands on either side and pressses the side walls of the hole. As long as the bolt is pulled the grip of the crown flap (1) becomes stronger. The nut (5) is then tightened such that the plate is pushed upward and in turn the rubber tubes get pressed and bulge against the side walls of the hole in the mine roof. When the plate is sufficiently tightened against the roof surface, the operation is complete. The main advantages of the present invention are : 1. It is a quick setting type roofbolt 2. It does not require any cement or chemicals for fixing 3. It provides compaction to the side walls 4. It can provide considerable frictional resistance to side walls and also tension to the bolt 5. It can be recovered if necessary 6. It can provide more anchorage strength than point anchored type or full grouted type roof bolt 8. It is very easy to operate and handle 7. It is economic We Claim : 1) An improved roof bolt useful for supporting mine/tunnel roofs instantly and compactly, which comprises a bolt rod (3) having a threaded portion (7), the said threaded end being provided with means (4,5) such as a plate (4) with hole (9) and a nut (5), the other end of the said bolt rod being characterized in that having an outwardly flaring conical bulged head (2), the said bulged head (2) being provided with a matching flexible crown cap (1), the said crown cap (1) being provided on its outer periphery with downward teeth (8), the said bolt rod (3) having a plurality of flexible tubular sections (6) throughout its length in between the said plate (4) and the head (2) 2) An improved roof bolt useful for supporting mine/tunnel roofs instantly and compactly, substantially as herein described with reference to the drawings accompanying this specification.

Full Text

This invention relates to an improved roof bolt useful for supporting mine/tunnel roofs instantly and compactly.
In underground mines providing roof support is of utmost importance primarily to avoid roof collapse.
The underground mines generally produce minerals by making tunnels. Therefore, thousands of kilometers of tunnels are to be maintained for travelling and conveying purposes in mines. Mine openings/tunnels require supporting properly to avoid accidents which occurs due to fall of roofs. There are direct supporting by vertical pieces of support and other indirect supports are roof bolts which actually increase the inherent bonding strength of roof, rather makeing the roof self supported.
Roof bolting generally involves inserting steel bolts within the holes drilled in the roof rocks and holding the same by means. There are two types of roof bolts generally available in the mining field.
The first is point anchored type being fixed at the top point either by mechanical method or by using an organic resin capsule with a roof bolt.
The second one is full grouted bolt where the hole is filled with cement slurry or any cement grout mixture.
The limitation of the point anchored roof bolts is that it

can not provide sufficient anchorage strength if the rock of very point is not competent enough, though it can provide ten-sional force to the lower layers of rock by tightening the plate on roof surface and it is possible to place it instantly.
The drawbacks of the full grouted roof bolt is that it can not provide the anchorage strength immediately and the process is time taking. In case of withdrawing the bolts from the fallen roof it is also not possible to take out the bolts as it is cemented with the broken lump. It Is also not possible to provide sufficient tension to the plate as the bolt is fully grouted.
Therefore, there is a definite need for a roof bolt which can be instantly fixed onto the mine/tunnel roof and also provide compaction with the side walls by increasing frictional force in between,thus providing a more powerful anchorage strength.
The main object of the present invention is to provide an improved roof bolt useful for supporting mine/tunnel roofs, which obviates the above noted drawbacks of the hitherto known roof bolts.
Another object of this invention Is to provide an improved roof bolt which will be supporting the mine roof Instantly and also filling the drill hole compactly.
The Figures - 1, 2 & 3 of the drawing accompanying this specification shows the schematic diagram of the device of the

present invention.
The various components are a bolt(3) with conical bulged head(2)and threaded(7) at lower portion, a plate(4), a nut (5), a metallic inverted U-Section semi round piece (1) having teeth on outer sides, some pieces of rubber tubes (6) having central holes.
Accordingly, the present invention provides an improved roof bolt useful for supporting mine/tunnel roofs instantly and compactly, which comprises a bolt rod (3) having a threaded portion(7) , the said threaded end being provided with means (4,5) such as a plate (4) with a hole (9) and a nut (5), the other end
of the said bolt rod being characterized in that having an outwardly
flaring conical bulged
head (2) , the said bulged head (2) being provided with a matching flexible crown cap (1), the said crown cap (1) being provided on its outer periphery with downward teeth (8), the said bolt rod (3) having a plurality of flexible tubular sections (6) throughout its length in between the said plate (4) and head (2).
The operation of the device of the present invention is as follows :
The flexible tubular sections(6) such as rubber tubing pieces are pushed in the rod of the bolt (3) in between the head (2) and the plate (4) supported by the nut (5). The bolt is then pushed into an hole drilled in the rock of mines roof keeping the head of bolt on the top side. When the head reaches the end of the hole, the rod is pulled back against the round rubber pieces

and the plate. As the larger diameter head comes down, the crown flap (1) expands on either side and pressses the side walls of the hole. As long as the bolt is pulled the grip of the crown flap (1) becomes stronger. The nut (5) is then tightened such that the plate is pushed upward and in turn the rubber tubes get pressed and bulge against the side walls of the hole in the mine roof. When the plate is sufficiently tightened against the roof surface, the operation is complete.
The main advantages of the present invention are :
1. It is a quick setting type roofbolt
2. It does not require any cement or chemicals for fixing
3. It provides compaction to the side walls
4. It can provide considerable frictional resistance to side
walls and also tension to the bolt
5. It can be recovered if necessary
6. It can provide more anchorage strength than point
anchored type or full grouted type roof bolt
8. It is very easy to operate and handle
7. It is economic

We Claim :
1) An improved roof bolt useful for supporting mine/tunnel roofs
instantly and compactly, which comprises a bolt rod (3) having a
threaded portion (7), the said threaded end being provided with means
(4,5) such as a plate (4) with hole (9) and a nut (5), the other end of
the said bolt rod being characterized in that having an outwardly
flaring conical bulged head (2), the said bulged head (2) being
provided with a matching flexible crown cap (1), the said crown cap
(1) being provided on its outer periphery with downward teeth (8), the
said bolt rod (3) having a plurality of flexible tubular sections (6)
throughout its length in between the said plate (4) and the head (2)
2) An improved roof bolt useful for supporting mine/tunnel roofs
instantly and compactly, substantially as herein described with
reference to the drawings accompanying this specification.

Documents:

2383-del-1998-abstract.pdf

2383-del-1998-claims.pdf

2383-del-1998-correspondence-others.pdf

2383-del-1998-correspondence-po.pdf

2383-del-1998-description (complete).pdf

2383-del-1998-drawings.pdf

2383-del-1998-form-1.pdf

2383-del-1998-form-19.pdf

2383-del-1998-form-2.pdf

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Patent Number

215877

Indian Patent Application Number

2383/DEL/1998

PG Journal Number

12/2008

Publication Date

21-Mar-2008

Grant Date

05-Mar-2008

Date of Filing

13-Aug-1998

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	SIBNATH MAITY	CENTRAL MINING RESEARCH INSTITUTE, DHANBAD, BIHAR, INDIA.

PCT International Classification Number

E21D

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA