U.S. patent application number 12/156415 was filed with the patent office on 2008-12-04 for mine roof cable bolt, coupler and method.
This patent application is currently assigned to F. M. Locotos Co., Inc.. Invention is credited to Frank M. Locotos.
Application Number | 20080298904 12/156415 |
Document ID | / |
Family ID | 40088402 |
Filed Date | 2008-12-04 |
United States Patent
Application |
20080298904 |
Kind Code |
A1 |
Locotos; Frank M. |
December 4, 2008 |
Mine roof cable bolt, coupler and method
Abstract
A metal coupling used to join a strand cable with a threaded
metal mine roof bolt includes a first portion having a first
opening that is threaded to receive an engage with the bolt. The
coupling includes a second portion having a second opening to
receive and engage with the cable. A mine roof support includes a
strand cable. The support includes a threaded metal mine roof bolt.
The support includes a metal coupling which joins the strand cable
with the threaded metal mine roof bolt that supports at least 1 ton
of load from a mine roof when disposed in the mine roof. A method
for forming a mine roof support includes the steps of screwing a
threaded metal mine roof bolt into a first opening that is threaded
of a metal coupling. There is the step of inserting a strand cable
into a second opening of the metal coupling. There is the step of
swagging the cable inside the coupling.
Inventors: |
Locotos; Frank M.;
(Bridgeville, PA) |
Correspondence
Address: |
Ansel M. Schwartz
Suite 304, 201 N. Craig Street
Pittsburgh
PA
15213
US
|
Assignee: |
F. M. Locotos Co., Inc.
|
Family ID: |
40088402 |
Appl. No.: |
12/156415 |
Filed: |
May 29, 2008 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60932846 |
Jun 1, 2007 |
|
|
|
Current U.S.
Class: |
405/302.2 |
Current CPC
Class: |
E21D 21/0046
20130101 |
Class at
Publication: |
405/302.2 |
International
Class: |
E21D 21/00 20060101
E21D021/00 |
Claims
1. A mine roof support comprising: a strand cable; a threaded metal
mine roof bolt; and a metal coupling which joins the strand cable
with the threaded metal mine roof bolt that supports at least 1 ton
of load from a mine roof when disposed in the mine roof.
2. A support as described in claim 1 wherein the strand cable is
swagged inside the coupling.
3. A support as described in claim 2 wherein the threaded metal
mine roof bolt is threateningly engaged inside the coupling.
4. A support as described in claim 3 wherein the bolt is swagged
inside the coupling.
5. A support as described in claim 3 wherein the strand cable is
plain, galvanized, epoxy coated, or covered with grit to enhance
its grip.
6. A support as described in claim 1 including a mechanical
expansion anchor and a second metal coupling to affix a mechanical
expansion anchor at the top of the cable.
7. A support as described in claim 2 including an expansion anchor
attached to the bolt.
8. A support as described in claim 7 including a bearing plate
attached to the bolt.
9. A support as described in claim 8 including a resin
cartridge.
10. A support as described in claim 9 including means for mixing
resin in the resin cartridge placed on the strand cable.
11. A support as described in claim 10 wherein the mixing means is
buttons swagged to the cable, or a spiral wire mixer affixed around
the cable.
12. A metal coupling used to join a strand cable with a threaded
metal mine roof bolt comprising: a first portion having a first
opening that is threaded to receive an engage with the bolt; and a
second portion having a second opening to receive and engage with
the cable.
13. A method for forming a mine roof support comprising the steps
of: screwing a threaded metal mine roof bolt into a first opening
that is threaded of a metal coupling; inserting a strand cable into
a second opening of the metal coupling; and swagging the cable
inside the coupling.
14. A method for reinforcing a mine roof comprising the steps of:
placing a resin cartridge into a hole in the mine roof; puncturing
the cartridge with a strand cable attached to a metal coupling at
the coupling's first end, with a threaded metal bolt attached to a
threaded second end of the coupling of a bolt; and rotating the
bolt to mix the resin and to set an expansion anchor attached to
the threaded bolt.
Description
FIELD OF THE INVENTION
[0001] The present invention is related to a mine roof bolt. (As
used herein, references to the "present invention" or "invention"
relate to exemplary embodiments and not necessarily to every
embodiment encompassed by the appended claims.) More specifically,
the present invention is related to a mine roof bolt that features
a coupling which joins a multi-strand cable to a rigid bolt and
tensioning of the combined bolt is accomplished by the use of an
expansion anchor attached to the top end of either the rigid bolt
or cable. Resin can be used in both means to assist in anchoring to
the rock in the borehole.
BACKGROUND OF THE INVENTION
[0002] This section is intended to introduce the reader to various
aspects of the art that may be related to various aspects of the
present invention. The following discussion is intended to provide
information to facilitate a better understanding of the present
invention. Accordingly, it should be understood that statements in
the following discussion are to be read in this light, and not as
admissions of prior art.
[0003] Mine roof supports are used to reinforce the roofs of mines.
Commonly, these supports are made of a solid rigid metal bar. The
use of such a bar can be relatively expensive and by definition
inflexible. The use of cable is relatively cheaper and relatively
flexible as compared to the bar. The problem is to somehow or other
integrate the use of the cable to make an effective mine roof
support with the advantages of a rigid metal bolt. The present
invention solves this problem by using a special coupling to form a
mine roof bolt that has both a strand cable and a rigid bolt
coupled together with the coupling.
BRIEF SUMMARY OF THE INVENTION
[0004] The present invention pertains to a metal coupling used to
join a strand cable with a threaded metal mine roof bolt. The
coupling comprises a first portion having a first opening that is
threaded to receive an engage with the bolt. The coupling comprises
a second portion having a second opening to receive and engage with
the cable.
[0005] The present invention pertains to a mine roof support. The
support comprises a strand cable. The support comprises a threaded
metal mine roof bolt. The support comprises a metal coupling which
joins the strand cable with the threaded metal mine roof bolt that
supports at least 1 ton of load from a mine roof when disposed in
the mine roof.
[0006] The present invention pertains to a method for forming a
mine roof support. The method comprises the steps of screwing a
threaded metal mine roof bolt into a first opening that is threaded
of a metal coupling. There is the step of inserting a strand cable
into a second opening of the metal coupling. There is the step of
swagging the cable inside the coupling.
[0007] The present invention pertains to a method for reinforcing a
mine roof. The method comprises the steps of placing a resin
cartridge into a hole in the mine roof. There is the step of
puncturing the cartridge with a strand cable attached to a metal
coupling at the coupling's first end, with a threaded metal bolt
attached to a threaded second end of the coupling of a bolt. There
is the step of rotating the bolt to mix the resin and to set an
expansion anchor attached to the threaded bolt.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0008] In the accompanying drawings, the preferred embodiment of
the invention and preferred methods of practicing the invention are
illustrated in which:
[0009] FIG. 1 is a representation of a coupling of a mine roof bolt
of the present invention.
[0010] FIG. 2 is a representation of a mine roof of the present
invention.
[0011] FIG. 3 is a representation of an alternative embodiment of a
mine roof bolt of the present invention.
[0012] FIG. 4 is a representation of the coupling in regard to
dimensions.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring now to the drawings wherein like reference
numerals refer to similar or identical parts throughout the several
views, and more specifically to FIG. 1 thereof, there is shown a
metal coupling 1 used to join a strand cable 2 with a threaded
metal mine roof bolt 14. The coupling 1 comprises a first portion
having a first opening that is threaded to receive an engage with
the bolt 14. The coupling 1 comprises a second portion having a
second opening to receive and engage with the cable 2.
[0014] The present invention pertains to a mine roof support 100,
as shown in FIGS. 2 and 3. The support 100 comprises a strand cable
2. The support 100 comprises a threaded metal mine roof bolt 14.
The support 100 comprises a metal coupling 1 which joins the strand
cable 2 with the threaded metal mine roof bolt 14 that supports at
least 1 ton of load from a mine roof when disposed in the mine
roof.
[0015] Preferably, the strand cable 2 is swagged inside the
coupling 1. The threaded metal mine roof bolt 14 is preferably
threadingly engaged inside the coupling 1. Preferably, the bolt 14
is swagged inside the coupling 1. The strand cable 2 can be plain,
galvanized, epoxy coated, or covered with grit to enhance its grip.
The support 100 can include a mechanical expansion anchor 8 and a
second metal coupling 1 to affix the mechanical expansion anchor 8
at the top of the cable 2. Preferably, the support 100 includes an
expansion anchor 8 attached to the bolt 14. The support 100
preferably includes a bearing plate 11 attached to the bolt 14.
[0016] There can be a resin cartridge 9. The support 100 can
include means 7 for mixing resin in the resin cartridge 9 placed on
the strand cable 2. Preferably, the mixing means 7 is buttons
swagged to the cable 2, or a spiral wire mixer affixed around the
cable 2.
[0017] The present invention pertains to a method for reinforcing a
mine roof. The method comprises the steps of placing a resin
cartridge 9 into a hole in the mine roof. There is the step of
puncturing the cartridge 9 with a strand cable 2 attached to a
metal coupling 1 at the coupling's first end, with a threaded metal
bolt 14 attached to a threaded second end of the coupling 1 of a
bolt 14. There is the step of rotating the bolt 14 to mix the resin
and to set an expansion anchor 8 attached to the threaded bolt
14.
[0018] The present invention pertains to a method for forming a
mine roof support 100. The method comprises the steps of screwing a
threaded metal mine roof bolt 14 into a first opening that is
threaded of a metal coupling 1. There is the step of inserting a
strand cable 2 into a second opening of the metal coupling 1. There
is the step of swagging the cable 2 inside the coupling 1.
[0019] In the operation of the invention, a novel coupling 1 to
join a rigid mechanical mine roof bolt 14 to a strand cable 2
making it one piece is shown in FIG. 1.
[0020] Referring to FIG. 1, the special coupling 1 has a certain
length 5 of which is swagged to the strand cable 2. As also shown
in FIG. 1, the threaded end 4 of a rigid bolt 14 is threadedly
engaged with threads 3 inside coupling 1.
[0021] A two-section bolt 14 shown in FIG. 2 features a strand
cable 2 swagged inside the coupling, 1 which in turn is threadedly
engaged to a mechanical bolt 14. The mechanical bolt 14 has an
expansion anchor 8 on the threaded end 4 with emerging threads 316
at the top, which connect to the coupling 1.
[0022] FIG. 2 shows a strand cable 2 with any of several means 7 of
mixing resin in a cartridge 9 form pushed by the leading-end 15 of
the bolt 14 as they are being inserted into a drilled hole in the
roof of a mine or tunnel.
[0023] The strand cable 2 (which can be plain, galvanized, epoxy
coated, etc.) is connected to a rigid mechanical bolt 14 (FIG. 1)
via a special coupling 1.
[0024] The strand cable 2 is swagged inside the coupling 1, and the
mechanical bolt 14 is threadedly engaged to it or by other
techniques easily determined by those skilled in the art. (i.e.
swagging also).
[0025] The mechanical bolt 14 has threads 3 (FIG. 2) long enough on
top to not only accept the expansion anchor 8, but also enough to
engage the special coupling 1.
[0026] The mechanical bolt 14 also has a bearing plate 11 and
optional anti-friction washer 12 assembled at the head-end 13.
(FIGS. 2 and 3.)
[0027] The method of installation is to have all components
assembled prior to insertion. The resin cartridge 9 or cartridges 9
are placed in the hole. The bolt 14 lead-end is inserted in the
hole. In low roof areas, the top cable-end can be bent to insert in
the hole. This is advantageous over sectional rigid bolts, which
must be connected after the lead portion of the bolt 14 is placed
in the hole, then the head or bottom end, is placed in the pod or
drive of the bolting machine. The bolting machine then raises the
entire bolt 14 up and through the resin. The drive of the bolting
machine then turns the entire bolt 14 enabling the resin to be
mixed and the expansion anchor 8 to set. The bolt 14 is tensioned
initially from the expansion anchor 8 to the head end. After the
expansion anchor 8 is set, the resin surrounding the cable 2
hardens and forms an additional anchored zone above.
[0028] An alternate method is to use the coupling 1 to join the two
pieces of the bolt 14 (FIG. 3) TOP--cable 2, plus bottom rigid bolt
14 with the coupling 1. Also, place a novel coupling 1 at the top
of the cable 2 so as to join the cable 2 to an expansion anchor 8
with the system. The bolt 14 assembly is tensioned from the top to
the bottom of the head-end. A resin cartridge 9 may or may not be
used to grout the top area.
[0029] A description of the coupling 1 is now provided with
references to FIG. 2.
[0030] The coupling 1 joins cable 2 with threaded bolt 14. The bolt
14 is a rigid mechanical bolt 14. It has a threaded end 4 at the
top, which engages the tapped end of the special coupling 1. The
opposite or bottom end is the drive end. The drive end may be an
engaged head or fixed threadedly engaged nut. The cable 2 is
swagged inside the special coupling 1.
[0031] The strand cable 2 is preferably an ASTM A416, Grade 270K,
0.600'' Diameter, Typical Ultimate Strength at 59,000#.
[0032] The bolt 14 is preferably ASTM F432, 7/8'' Diameter, Grade
75 Mechanical Bolt, Minimum Ultimate Load at 46,200#. Typical Range
of Ultimate Strength at 55,000# to 59,000#.
[0033] The coupling 1 preferably has a tensile strength of 91,000
psi. This part is stronger than the combination of cable 2 and bolt
14 when Pull Tested--The 7/8'' Bolt would usually break first. The
cable 2 typical range of Ultimate Strength--55,000#-59,000#.
[0034] With reference to FIG. 4:
TABLE-US-00001 Range a. Length of thread inside coupling 1/2''-3''
b. Length of swage onto cable 2''-20'' c. Inside diameter of
coupling 1/4''-2'' d. Outside diameter of coupling 3/4''-4'' e.
Wall thickness of coupling where 1/16''-1'' coupling is swaged to
cable f. Interior threads of coupling which 1/4''-2'' join to rigid
roof bolt. Thread Design matched to bolt it joins. g. Gap between
cable and bolt inside coupling.
[0035] Preferred Example:
TABLE-US-00002 a. 1'' b. 4-3/4'' c. .690'' d. 1.3'' e. .305'' f.
7/8'' National Course Thread-Right Hand g. 1/4''
[0036] Material--41IL40 91,000 PSI Tensile
[0037] Coupling Material--Steel or Casting (Metal)
[0038] How coupling 1 is manufactured:
[0039] Steel--A round steel bar is cut to length. One end is
drilled and tapped to accept the threaded end 4 of a rigid bolt.
The other end is drilled to the proper diameter to accept the cable
for swagging.
[0040] Steel Tubing--Tubing with proper O.D. and I.D. is cut to
length. One end is drilled and tapped to accept the rigid bolt. The
other end already has proper I.D. to accept the cable.
[0041] Casting--Molten metal is poured into a mould to form the
coupling 1. Then the one end is tapped to form threads.
[0042] The advantages of having the Rigid Bolt Section 14 with the
Cable include: [0043] 1. Helps to keep entire bolt (including cable
portion) from twisting too much during tensioning; and, [0044] 2.
Improves torqueing of the bolt which can cause back spin and loss
of load if only cable is used for entire length.
[0045] Although the invention has been described in detail in the
foregoing embodiments for the purpose of illustration, it is to be
understood that such detail is solely for that purpose and that
variations can be made therein by those skilled in the art without
departing from the spirit and scope of the invention except as it
may be described by the following claims.
* * * * *