U.S. patent number 3,601,994 [Application Number 04/849,963] was granted by the patent office on 1971-08-31 for method and apparatus for mine roof support.
Invention is credited to Alex J. Galis.
United States Patent |
3,601,994 |
Galis |
August 31, 1971 |
METHOD AND APPARATUS FOR MINE ROOF SUPPORT
Abstract
A roof support for underground mines having angular support
holes drilled in the roof adjacent the pillar walls. One end of a
flexible cable reeved about a wedge member is inserted in one of
the support holes and the end of the cable is wedged against the
side walls of the support hole. The other end of the cable is
inserted in the other support hole on the opposite side of the
passageway with the cable end portion reeved about a wedge member.
The wedge member with the cable end portion is urged upwardly into
the other support hole until the cable stretches a preselected
amount. The wedge member is then released and wedges the cable end
portion against the walls of the other support hole to provide a
cable under tension extending between the angularly positioned
support holes and supporting the roof therebetween. Where desired,
elongated support members may be positioned between pairs of
tensioned cables and the roof to provide additional support.
Another embodiment includes inserting separate strands of flexible
cable in both support holes, connecting the free ends of the
strands to each other and wedging one cable in one support hole and
exerting a force on the other wedge member in the other bolt hole
to tension the connected strand members.
Inventors: |
Galis; Alex J. (Albany,
GA) |
Family
ID: |
25306933 |
Appl.
No.: |
04/849,963 |
Filed: |
August 14, 1969 |
Current U.S.
Class: |
405/288; 411/344;
24/115K |
Current CPC
Class: |
E21D
11/006 (20130101); Y10T 24/3991 (20150115) |
Current International
Class: |
E21D
11/00 (20060101); E21d 021/00 () |
Field of
Search: |
;61/45B,45R ;52/166,223L
;24/136K,126K,132,132HA,132HL,132PT,132CH,134,134K ;85/3,79
;287/75,83 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
271,284 |
|
Aug 1964 |
|
AU |
|
943,667 |
|
Dec 1963 |
|
GB |
|
694,725 |
|
Sep 1930 |
|
FR |
|
1,143,471 |
|
Feb 1963 |
|
DT |
|
407,014 |
|
Aug 1966 |
|
CH |
|
Primary Examiner: Taylor; Dennis L.
Claims
I claim:
1. A method for supporting a mine roof comprising,
drilling a pair of spaced support holes in a mine roof,
reeving a first end portion of a flexible metallic cable around a
first wedge member,
reeving the other end portion of said flexible metallic cable
around a second wedge member,
inserting said first wedge member with said flexible metallic cable
first end portion reeved therearound into one of said support holes
with said cable end portion abutting the sidewall of said support
hole,
wedging said cable first end portion between said first wedge
member and said support hole sidewall,
inserting said second wedge member with said flexible metallic
cable other end portion reeved therearound into the other of said
support holes with said cable other end portion abutting the
sidewall of said respective support hole,
wedging said cable second end portion between said second wedge
member and said support hole sidewall, and
exerting a tension on said flexible cable between said end portions
to urge said cable upwardly against said mine roof to support said
roof thereabove.
2. A method for supporting a mine roof as set forth in claim 1
which includes,
exerting a sufficient tension on said flexible metallic cable to
stretch said cable below its elastic limit, and
thereafter wedging the other end of said cable against said other
support hole sidewall.
3. A method for supporting a mine roof as set forth in claim 1
which includes,
positioning elongated roof support members between said tensioned
cable and said roof surface.
4. A method for supporting a mine roof as set forth in claim 1 in
which,
said flexible cable includes a first section and a second
section,
said first section having a first end portion and a second end
portion,
inserting said first section first end portion in one of said
support holes,
wedging said first section first end portion between said first
wedge member and said support hole sidewall,
said second section having a first end portion and a second end
portion,
inserting said second section first end portion into said other
support hole,
wedging said second section first end portion between said second
wedge member and said other support hole sidewall,
positioning said first section second end portion in overlapping
relation with said second section second end portion,
exerting a tension on said first section and said second section
and thereafter,
clamping said first section to said second section adjacent said
second end portions of both of said sections while maintaining a
tension on said sections to thereby provide a support for the mine
roof thereabove.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to mine roof supports and more particularly
to a flexible cable type mine roof support.
2. Description of the Prior Art
Mine roofs are now presently supported by roof bolts that have
expansion shells and bearing plates. Vertical bolt holes are
drilled in the mine roof and the roof bolts are inserted therein
with the baseplate adjacent the roof surface. The bolts are rotated
to expand the shell adjacent the end portion of the bolt to engage
the bolt hole and to squeeze or compress the rock strata
therebetween. In some installations transverse or longitudinally
oriented wood or metal beams are first positioned adjacent the roof
surface and the roof bolt members extend therethrough. This latter
arrangement provides added roof support, especially for the rock
strata adjacent the roof surface.
U.S. Pat. No. 3,427,811 discloses a roof support system that
includes drilling a pair of bolt holes in the roof adjacent the
pillar walls. Conventional roof bolts are positioned in the bolt
holes and a flexible cable is connected to the bearing plate
portion of the spaced roof bolts. The flexible cable is then
tensioned by means of a turnbuckle.
SUMMARY OF THE INVENTION
Briefly, the invention relates to a method and apparatus for
supporting a mine roof that eliminates the use of conventional roof
bolts and provides the desired support for the mine roof. One end
of a flexible cable is secured in a first support hole by means of
a wedge member and the other end of the cable is secured in a
second support hole spaced from the first support hole by a wedge
member. The cable is tensioned between the end portions and
supports the roof therebetween.
With the above arrangement the use of conventional roof bolts is
eliminated and support is provided by the tensioned flexible cable.
Suitable bearing means may be provided between the bolt holes.
Accordingly, the principal object of this invention is to provide a
method and apparatus for mine roof support that eliminates the use
of conventional roof bolts.
Another object of this invention is to provide a method and
apparatus for mine roof support wherein the support is provided by
a flexible cable.
These and other objects and advantages of this invention will be
more completely disclosed and described in the following
specification, the accompanying drawings and the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view in elevation of a mine passageway with
the roof support of the present invention.
FIG. 2 is a view similar to FIG. 1 illustrating another embodiment
of the mine roof support.
FIG. 3 is a fragmentary view in elevation and in section of one of
the support holes illustrating the manner in which the cable end
portion and wedge member are positioned therein.
FIG. 4 is a view similar to FIG. 3 illustrating the wedge member in
a rotated position wedging the flexible cable against the sidewalls
of the support hole.
FIG. 5 is a perspective view of the wedge member with an end
portion of the flexible cable reeved therearound.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings there is illustrated an underground mine
having a passageway or haulageway 10 with a roof portion 12 and
side or pillar walls 14. A pair of holes 16 and 18 are drilled
upwardly into the roof through the rock strata thereabove to a
predetermined depth. The holes 16 and 18 are preferably drilled at
an angle, as illustrated in FIGS. 1 and 2 and adjacent the pillar
walls 14 and have cylindrical sidewalls 20 formed in the rock
strata.
Referring to FIG. 5 a wedge member generally designated by the
numeral 22 has a body portion 24 with serrated end walls 26 and 28.
Recessed portions 30 and 32 are provided in the body portion 24.
The depth of the recessed portions 30 and 32 is preferably such
that a portion of the cable extends outwardly beyond the serrated
end walls 26 and 28, as illustrated in FIG. 5.
Referring to FIG. 1 a flexible cable 34 has a first end portion 36
and a second end portion 38. The first end portion 36 is reeved or
looped about the wedge member 22 as illustrated in FIGS. 4 and 5
with portions of the cable positioned in the wedge member recessed
portions 30 and 32. The cable end portion 36 and wedge 22 are
inserted in the hole 16 until the wedge 22 is adjacent the base of
the hole. A suitable tool, as that diagrammatically illustrated in
FIG. 3 and designated by the numeral 40, is utilized to insert the
wedge member with the cable end portion 36 reeved therearound. The
tool 40 is retained in the position illustrated in FIG. 3 until a
sufficient tension is exerted on the cable 34 to wedge the cable
end portion 36 between the hole wall 20 and the wedge member 22 to
maintain the wedge member 22 and cable end portion 36 in the bolt
hole 16 adjacent the hole base portion.
The cable other end portion 38 is similarly reeved about a similar
wedge member 22 and inserted in the bolt hole 18. Where desired,
longitudinal beams 42 and 44 may be positioned between the roof
surface 46 and the intermediate portion of the cable 34. A suitable
tool similar to that illustrated in FIGS. 2 and 3 and designated by
the numeral 40 urges the cable end portion 38 and wedge member 22
upwardly into the hole 18. A sufficient force is exerted on the
wedge member 22 in hole 18 to tension the cable 34 and preferably
sufficient tension is provided by the tool 40 to stretch the cable
34 to a degree that it remains below its elastic limit. The tool 40
is then removed from the hole 18 and the tension on cable 34 pivots
the wedge member 22 until the serrated walls 26 and 28 are imbedded
in the hole sidewalls 20 with the cable end portion wedged between
the wedge member 22 and the walls 20 of the hole 18. The wedging
position of the wedge member 22 is illustrated in FIG. 4. With this
arrangement the cable 34 is in tension between the wedge members 22
in the holes 16 and 18 and exerts an upward force against the
longitudinal beams 42 and 44 to support the roof 12.
Where it is desired to use two separate spools of cable, separate
lengths 48 and 50 are cut from each spool and their end portions 52
and 54 are clamped together by suitable cable clamps 56 and their
free end portions 58 and 60 are inserted in similar holes 62 and
64. Wedge members similar to members 22 have the end portions 58
and 60 looped therearound and may be simultaneously urged upwardly
into the holes 62 and 64 to exert a tension on the connected cables
48 and 50 to stretch the cables so that upon release of the tools
40 the wedge members 22 pivot and wedge the cable end portions 58
and 60 against the wall 20 of the holes 62 and 64.
Alternatively the separate lengths of cable 48 and 50 may first
have their end portions 58 and 60 inserted in holes 62 and 64.
Sufficient tension is exerted on the separate lengths of cable to
wedge the end portions 58 and 60 in the holes 62 and 64. The end
portions 52 and 54 are positioned adjacent each other and are
further tensioned by a suitable tensioning device. Clamps 56 secure
the end portions of cables 48 and 50 while under tension to provide
support for the roof therebetween.
It should be understood where desired, bearing members may be
positioned between the tensioned cable and the roof surface 12
adjacent the holes. It should also be understood that the spaced
holes may be arranged longitudinally in the passageway rather than
transversely as illustrated in FIGS. 1 and 2. Other suitable wedge
members having other configurations may be used to wedge the cable
end portions against the wall of the hole and maintain the desired
tension on the cable for support purposes.
With the above described roof support apparatus both ends of the
cable may be simultaneously inserted in the spaced holes and
tension exerted on the cable simultaneously by a pair of tools or
one end of the cable may be first wedged in one of the holes and
the other end of the cable thereafter wedged in the other spaced
hole.
According to the provisions of the patent statutes, I have
explained the principle, preferred construction and mode of
operation of my invention and have illustrated and described what I
now consider to represent its best embodiments.
* * * * *