HIGH-CARBON CHAIN LINK FENCE FOR MINING INDUSTRY

CLOTURE A MAILLES LOSANGEES A HAUTE TENEUR EN CARBONE POUR L'INDUSTRIE MINIERE

English Abstract

The present invention relates to a chain link type fence. The chain link type fence can be used in the mining industry, such as in a mining tunnel for tunneling and shotcrete applications. A chain link fence arranged according to the present invention advantageously can have a relatively lower weight, can be more easily manipulated and installated, can have a relatively lower thickness, and can have an increased strength and breaking load.

French Abstract

La présente invention concerne une clôture de type à mailles losangées. La clôture de type à mailles losangées peut être utilisée dans l'industrie minière, comme un tunnel de mine pour des applications de béton projeté et de creusement de tunnel. Une clôture à mailles losangées arrangée selon la présente invention peut avantageusement avoir un poids relativement inférieur, peut être facilement manipulée et installée, peut comporter une épaisseur relativement inférieure et peut avoir une force et une force de rupture améliorées.

Claims

WHAT IS CLAIMED IS:
1. Use of a chain link type of fence to reinforce a tunnel, said chain link
type of
fence having steel wires having a carbon content ranging from 0.45 percent by
weight to 0.57 percent by weight and having a diameter ranging from about 3.50
mm to about 4.0 mm.
2. Use according to claim 1, wherein said steel wires have a composition
corresponding to SAE1050.
3. Use according to claim 1, wherein said chain link type of fence comprises
meshes, said meshes having a square form Y mm x Y mm, where Y ranges from
about 60 mm to about 90 mm.
4. Use according to claim 1, wherein said steel wires have a diameter of about
4.0 mm or less.
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Description

CA 02631381 2010-07-23
HIGH-CARBON CHAIN LINK FENCE FOR MINING INDUSTRY
Field of the Invention
[00021 The present invention relates to a chain link type fence. The present
invention also relates to the use of a chain link type fence in the mining
industry, such as in a mining tunnel.
Background of the Invention
[0003) A chain link fence is perhaps the most economical type of fencing
available.
A conventional chain link fence is usually made of plain low carbon steel
that has a carbon content of 0.15 per cent by weight or lower. The
following types of chain link fence are common:
[0004) -- a chain link fence with meshes having a square form with a size of
100 mm x 100 mm, formed by a steel wire having a diameter of 5.10 mm;
[0005) -- a chain link fence with meshes having a square form with a size of
50 mm x 50 mm, formed by a steel wire having a diameter of 4.20 mm.
[0006) These existing conventional chain link fence types are widely used but
have
the following drawbacks:
[00071 -- the chain link fences have a relatively high weight and hence are
difficult to manipulate;
[0008) - the chain link fences are made with thick steel wire having a
relatively large diameter, which results in thick meshes;
[0009] -- the chain link fences have a relatively low strength.
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CA 02631381 2010-07-23
[0010] When used in the mining industry, these existing conventional chain
link
fences may not provide a sufficient reinforcement, as illustrated by FIGURE
1.
[0011] FIGURE 1 shows a prior art chain link fence 10 reinforcing the ceiling
12 of
a mine. Due to the low strength of chain link fence 10, this fence 10 is not
able to maintain the integrity of the ceiling 12 and hold stone material 14
for
a sufficiently long period of time. Because of the weakness of the chain link
fence 10, the fence 10 fails at its weakest spot and the stone material 14
pours down into the mine.
[0012] US patent US-A-2,188,869 discloses a so-called high-carbon fence. The
exact carbon content, however, is not mentioned. Nor is the disclosed
fence a chain link fence. Furthermore, the applications mentioned in US
'869 are not tunneling applications, such as in mining, and do not use
shotcrete.
[0013] German utility model DE-U-296 06 610 discloses a hexagonal mesh for use
in tunnels and mining. However, the utility model is silent with respect to
the carbon content of the mesh.
SUMMARY OF THE INVENTION
[0014] An object of the present invention is to provided a use of a chain link
type of
fence to reinforce a tunnel, the chain link type of fence having steel wires
having a carbon content ranging from 0.45 percent by weight to 0.57 percent
by weight and having a diameter ranging from about 3.50 mm to about 4.0
mm.
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CA 02631381 2008-05-16
Brief Description of the Drawings
[0017] FIGURE 1 illustrates a failure mode of a prior art chain link fence.
[ools] FIGURE 2 illustrates a chain link fence in a mining tunnel, according
to an
embodiment.
[0019] FIGURE 3 illustrates a chain link fence in a mining tunnel, according
to an
embodiment.
[0020] FIGURE 4 is a top view of a testing configuration for a chain link
fence,
according to an embodiment.
[0021] FIGURE 5 is a side view of the testing configuration of FIGURE 4.
Detailed Description
[0022] The present invention relates to a chain link fence. The fence can be
used
in the mining industry, such as in tunneling and shotcrete applications.
Aspects of the present invention include: (1) lowering the weight of chain
link fences, (2) facilitating the manipulation and installation of chain link
fences, (3) lowering the thickness of a chain link mesh, and (4) increasing
the strength and breaking load of a chain link mesh.
[0023] According to an embodiment, a chain link fence can be made of steel
wires
having a steel composition with a carbon content of 0.45 per cent by weight
or more. For example, a chain link fence can be made of steel wires having
a steel composition with a carbon content of 0.45 to 0.70 per cent by
weight. In another example, a chain link fence can be made of steel wires
having a steel composition with a carbon content of 0.45 to 0.57 per cent by
weight. In another example, a chain link fence can be made of steel wires
having a steel composition with a carbon content of 0.45 to 0.55 per cent by
weight. In another example, a chain link fence can be made of steel wires
having a steel composition that corresponds to SAE 1050.
[0024] According to an embodiment, a chain link fence can be made with meshes
that have a square form of Y mm x Y mm. For example, Y can range from
about 60 mm to about 90 mm. In another example, Y can range from about
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CA 02631381 2008-05-16
65 mm to about 85 mm. In another example, Y can range from about 70
mm to about 80 mm. In another example, Y can be about 75 mm.
[0025] According to an embodiment, a chain link fence can be made from steel
wires having a relatively small diameter. For example, a chain link fence
can be made from steel wires that have a diameter of about 4.0 mm or less.
In another example, a chain link fence can be made from steel wires that
have a diameter of about 3.00 mm to about 4.00 mm. In another example,
a chain link fence can be made from steel wires that have a diameter of
about 3.25 mm to about 4.00 mm. In another example, a chain link fence
can be made from steel wires that have a diameter of about 3.50 mm to
about 4.00 mm. In another example, a chain link fence can be made from
steel wires that have a diameter of about 3.50 mm to about 3.80 mm.
[0026) In another example, a chain link fence can be made from steel wires
having
a diameter of 3.66 mm and a composition corresponding to SAE 1050 to
form a chain link fence with mesh squares having a size of 75 mm. Such a
chain link fence weighs 2.5 kg / m2. In contrast, a 10006 fence, which is a
fence with a mesh size of 100 mm x 100 mm made from wire having a
diameter 5.10 mm, would weigh 3.5 kg / m2. Furthermore, a 5008 fence,
which is a fence with a mesh size of 50 mm x 50 mm made from wire
having a diameter of 4.20 mm, would weigh 4.8 kg / m2.
[0027] A chain link fence arranged according to the embodiments and examples
described herein can have a lower weight per square meter. By using
smaller diameter wire, a chain link fence can be provided with a lower
thickness and weight. Furthermore, because the chain link fence has a
relatively lower thickness, the chain link fence has a relatively high
flexibility
and can be more easily formed. By using wires made from a steel
composition with a relatively high carbon content, the chain link fence can
have an increased strength, such as tensile strength, and higher breaking
load, despite the use of steel wires with a relatively small diameter. Thus,
because the chain link fence is lighter and thinner, such a chain link fence
can be easily manipulated and installed while providing a chain link fence
with an increased strength and breaking load.
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CA 02631381 2008-05-16
[0028) A further advantage of a chain link fence arranged according to the
embodiments and examples described herein is that less material, such as
projected concrete or shotcrete, needs to be used because the fence is
thinner. This provides a savings in cost due to the decreased use of
materials.
[0029] According to an embodiment, a tunnel can be reinforced by a chain link
fence that is configured according to any of the embodiments and examples
described herein.
[0030] According to an embodiment, a method of using a chain link fence to
reinforce a tunnel can be practiced by providing a chain link fence
according to any of the embodiments and examples described herein and
reinforcing the tunnel with the chain link fence.
[0031] FIGURE 2 illustrates a chain link fence 20 that is used in a mine 22,
according to an embodiment. For example, the chain link fence 20 can be
used to reinforce the ceiling and/or wall of a tunnel in the mine 22. In the
example of FIGURE 2, the chain link fence 20 is used to reinforce a ceiling
about two side walls of a tunnel in a mine 22 in front of an open end of the
tunnel.
[0032] FIGURE 3 illustrates a chain link fence 30 that is used in a mine 32,
according to an embodiment. For example, chain link fence 32 can be
used to reinforce the ceiling and/or wall of a tunnel in the mine 32. In the
example of FIGURE 2, the chain link fence 30 is used to reinforce a ceiling
about two side walls of a tunnel in a mine 32 in front of an open end of the
tunnel.
[0033] FIGURE 4 is a top view of a testing configuration for a chain link
fence,
according to an embodiment. As shown in the example of FIGURE 4, a
chain link fence 40 can be connected to a testing frame 42 and a localized
load 50 can be applied to a center 44 of the fence 40. The tested chain link
fence 40 can be a 1 m x 1 m sample that is fixed to the testing frame 42.
The test can be arranged to simulate a load of rocks, such as a fence would
be loaded with in an underground mine.

CA 02631381 2008-05-16
[0034] FIGURE 5 is a side view of the testing configuration of FIGURE 4. As
shown in the example of FIGURE 5, the displacement of the fence 40
caused by the load 50 can be measured, along with the amount of the load
50 itself.
[0035] Conventional fences, such as chain link fences made out of 5.10 mm
diameter low carbon wire that form square meshes with a size of 100 mm,
have breaking loads that typically range from 3.8 tons to 5.1 tons.
[0036] An example of a chain link fence made out of steel wire with a
composition
corresponding to SAE 1050 with a diameter of 3.76 mm that form square
meshes with a size of 75 mm have breaking loads that range from 4.9 tons
to 6.2 tons.
[0037] The foregoing description of embodiments of the invention has been
presented for purposes of illustration and description. It is not intended to
be exhaustive or to limit the invention to the precise form disclosed, and
modifications and variations are possible in light of the above teachings or
may be acquired from practice of the invention. The embodiments were
chosen and described in order to explain the principals of the invention and
its practical application to enable one skilled in the art to utilize the
invention
in various embodiments and with various modifications as are suited to the
particular use contemplated. Other embodiments of the invention will be
apparent to those skilled in the art from consideration of the specification
and practice of the invention disclosed herein.
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Representative Drawing