Note: Descriptions are shown in the official language in which they were submitted.
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ROCK BOLTING SYSTEM, METHOD OF INSTALLING ROCK
BOLTS, AND FLEXIBLE BOLT CENTRALIZER
TECHNICAL FIELD
pooq The present invention relates generally to mining
equipment and, in particular, to rock bolting.
BACKGROUND
[0002] In a mine, ground support, e.g. rock bolts and
screening, is used to prevent rock falls. Several different
types of rock bolts may be used but all require that holes be
drilled in the rock first. This is
done with equipment known
as rock bolters. These are mobile units with a bolting head
attached. To drill
a hole in the rock to install ground
support, the bolting head is placed against the rock face
(which is called "stinging the face") and then a hole is
drilled into the rock. The unit
is then indexed to install
the ground support.
K00]
Conventionally, the bolter feeds have a fixed stinger.
This is the part of the feed that stabilizes the feed assembly
against the rock during the drilling process. With the
conventional systems, the whole feed assembly must move to the
rock face. In other
words, in conventional rock bolter
systems, the rock drill feed and the bolting feed are
connected together and thus extend and retract. This is
problematic in tight areas and in some cases makes indexing
difficult.
[0004] A need
therefore exists for an effective solution to
this technical problem.
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SUMMARY
[0005] In broad
terms, the present invention provides a novel
rock bolting system, a novel method of installing rock bolts,
and a novel flexible bolt centralizer.
[0006] The system in accordance with the present invention
has independently movable feeds to enable the system to
operate in confined spaces. In other
words, the system has
independently extendable and retractable hydraulic stinger,
drilling feed and bolting feed. This system therefore enables
the operator to sting the face using the hydraulic stinger
without having to move the entire assembly. This
system
facilitates stinging in tight places. The
drill and bolter
feeds can remain retracted to make indexing possible. With
the optional addition of a gripping mechanism and a rotation
element, this system may also function as a screen handler for
the installing of screening over a rock face.
[0007]
Accordingly, one aspect of the present invention is a
rock bolting system comprising a hydraulic stinger for
engaging a rock face to stabilize the rock bolting system, a
drill feed for drilling a hole in the rock face, and a bolting
feed for installing a rock bolt into the hole, wherein the
hydraulic stinger, the drill feed and the bolting feed are
each independently extendable and retractable.
[00os] Another
aspect of the present invention is a method of
installing ground support using a rock bolting system having a
hydraulic stinger, a drill feed, and a bolting feed. The
method entails independently extending the hydraulic stinger
to engage a rock face while the drill feed and bolting feed
remain retracted, and then, while the hydraulic stinger is
extended, independently extending the drill feed. The method
then involves drilling a hole in the rock with the hydraulic
stinger engaging the rock face, indexing the system to rotate
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the bolting feed into alignment with the hole with the
hydraulic stinger engaging the rock face, and installing a
rock bolt into the hole using the bolting feed.
P009] Yet
another aspect of the present invention is a bolt
centralizer for a bolting feed in a rock bolt system. The
bolt centralizer comprises a flexible body capable of
elastically flexing from an upright posture for centralizing a
rock bolt to a folded posture that permits a bolting feed to
advance. The centralizer comprises a passage for guiding the
rock bolt into a hole drilled by the rock bolt system. The
centralizer comprises a base for fastening the centralizer to
a sliding carriage that is adapted to slide over the rails of
the bolting feed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Further features and advantages of the present
invention will become apparent from the following detailed
description, taken in combination with the appended drawings,
in which:
VION FIG. 1
is a top view of a rock bolting system with the
hydraulic stinger, drill feed and bolting feed all retracted;
[0012] FIG. 2
is a top view of the rock bolting system after
rotation relative to the posture of FIG. 1 showing the
hydraulic stinger extended and the drill and bolting feeds
retracted;
[0013] FIG. 3
is a top view of the rock bolting system of
FIG. 1 showing the hydraulic stinger and drill feed extended
and the bolting feed retracted;
[0014] FIG. 4
is a top view of the rock bolting system after
rotation relative to the posture of FIG. 3 showing the
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hydraulic stinger and bolting feed extended and the drill feed
retracted;
[0016] FIG. 5 is a side view of a hydraulic stinger in its
extended posture;
[0016] FIG. 6 is a side view of the hydraulic stinger in its
retracted posture;
[0017] FIG. 7 is cross-sectional view of the hydraulic
stinger in its retracted posture; and
[0018] FIG. 8 is an exploded view of the hydraulic stinger;
[0019] FIG. 9 is side view of a variant of the (retracted)
hydraulic stinger in which the support tube is the cylinder;
[0on] FIG. 10 is a side view of the variant of FIG. 9 in its
extended posture;
[0021] FIG. 11 is a front view of a bolt centralizer in
accordance with an embodiment of the present invention;
[0022] FIG. 12 is a side view of the bolt centralizer of FIG.
11 in its upright posture;
[0023] FIG. 13 is a side view of the bolt centralizer of FIG.
11 in its flexed posture;
PON FIG. 14 is an isometric view of the bolt centralizer
of FIG. 11;
mom FIG. 15 is an isometric view of a screen-gripping
attachment for mounting to an end of the hydraulic stinger for
handling screens in accordance with another embodiment of the
present invention;
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[0026] FIG. 16 is a side view of the rock bolter with a
flexible traveling centralizer and a flexible forward
centralizer mounted to the bolting feed;
[0027] FIG. 17 is a rear view of the rock bolter of FIG. 16;
[0028] FIG. 18 is an isometric view of the traveling
centralizer mounted to the rock bolter;
[1:1029] FIG. 19 is an isometric view of the traveling
centralizer with a bolt in the passage;
[0030] FIG. 20
is an isometric view of a rail-mounted bolting
feed having a traveling centralizer mounted on rails and a
stationary centralizer mounted at a forward end of the rails;
[0031] FIG. 21 is an isometric view of the traveling
centralizer as it flexes;
[0032] FIG. 22 is an isometric view of the traveling
centralizer as it is completely bent/folded;
[0033] FIG. 23 is an isometric view of the forward
centralizer as it too flexes as the bolting feed advances; and
PM FIG. 24 is an isometric view of the forward
centralizer as it is completely bent/folded.
[0036] It will be noted that throughout the appended
drawings, like features are identified by like reference
numerals. It
should furthermore be noted that the drawings
are not necessarily to scale.
DETAILED DESCRIPTION
[0036] By way
of introduction, the present invention provides
a novel rock bolting system, a novel method of installing rock
bolts, and a novel flexible bolt centralizer. The
present
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invention provides improvements in the field of ground
support.
[0037] ROCK BOLTER
U018] In
general, a rock bolter is designed to drill a hole
and then to install a rock bolt into the hole. For the
purposes of the present specification, the term "rock bolt" is
meant to encompass rebar, split sets, expandable bolts,
anchors or any other bolt-like elements designed to be
installed in a hole in a rock face to provide ground support.
VIM] With
reference to FIGS. 1-4, the rock bolter (or rock
bolting system), which is generally designated by reference
numeral 10, has a hydraulic stinger 20, a drill feed 30 and a
bolting feed 40. Each is
hydraulically actuated using a
hydraulic actuator (hydraulic cylinder, piston and rod). In
the embodiments of the present invention, each of the stinger,
drill feed and bolting feed is independently movable (i.e.
each is independently extendable and retractable). In
operation, the rock bolter is brought close to a rock face. A
rock face means either the roof or the walls of a mine. Once
the rock bolter is properly positioned relative to the rock
face, the rock bolter extends the stinger to sting the rock
face. Stinging the rock face means engaging or contacting the
rock face. Stinging
is done to stabilize the rock bolter.
Therefore, stinging requires that the stinger press against
the rock face with sufficient force to stabilize the rock
bolter. With the stinger engaged against the rock face, the
rock bolter then extends the drill feed to drill a hole in the
rock. The
drill is withdrawn by retracting the drill feed
while the stinger remains in contact with the rock face. The
rock bolter is indexed to rotate the bolting feed into
alignment with the hole. The
bolting feed is then extended
(with the stinger still engaging the rock face). The stinger
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ensures that the bolting feed remains aligned with the hole
drilled by the drill feed. The bolting feed then installs the
rock bolt into the hole drilled by the drill feed. The
bolting feed is extended while the stinger is extended and the
drill feed is retracted. After bolting, the bolting feed may
be retracted. The stinger may then be retracted. The
installation of the rock bolt is complete. The rock
bolter
may be moved to a new location to drill another hole and
install another rock bolt.
[0040] FIG. 1
is a top view of a rock bolter or rock bolting
system 10 with the hydraulic stinger 20, drill feed 30 and
bolting feed 40 all retracted. The
stinger, drill feed and
bolting feed are all retracted into the retracted posture
shown in FIG. 1 when the rock bolter is stored, transported or
when manoeuvred in tight spaces. At the
outset of a rock
bolting operation, the rock bolter is in this posture.
V041] FIG. 2
is a top view of the rock bolting system after
rotation about a longitudinal axis. FIG. 2
shows the
hydraulic stinger 20 extended and the drill feed 30 and
bolting feed 40 retracted. FIG. 2
thus shows the posture of
the rock bolter when the stinger is extended to sting the rock
face.
[0042] FIG. 3 is a top view of the rock bolting system
showing the hydraulic stinger and drill feed extended and the
bolting feed retracted. FIG. 3 thus shows the posture of the
rock bolter when the drill feed is extended to drill the hole.
Drilling is performed while the stinger is extended against
the rock face to stabilize the rock bolter. Note that FIG. 3
shows the same non-rotated posture of FIG. 1.
[0043] FIG. 4
is a top view of the rock bolting system in the
same rotated posture as FIG. 2. FIG. 4
shows the hydraulic
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stinger and bolting feed extended and the drill feed
retracted. FIG. 4
shows the rock bolter after the hole has
been drilled and the drill feed has been retracted and after
the bolting feed has been extended to install the rock bolt
into the hole.
g044] The hydraulic stinger 20 described above may be
constructed in accordance with a first embodiment shown in
FIGS. 5-8 or in accordance with a second embodiment shown in
FIGS. 9-10.
[0045] FIG. 5
is a side view of a first embodiment of the
hydraulic stinger 20, shown in its extended posture while FIG.
6 shows the same embodiment of the hydraulic stinger in its
retracted posture. The
forward end of the stinger has a
bumper pad 25, as shown in the figures, for engaging/stinging
the rock face.
[0046] FIG. 7
is a cross-sectional view of the hydraulic
stinger in its retracted posture. FIG. 7 is a cross-sectional
view taken through section line 7-7 of FIG. 6.
pun FIG. 8
is an exploded view of the hydraulic stinger.
In the embodiment of FIGS. 5-8, the stinger has a flanged
support tube 21, an inner tube 22, a hydraulic cylinder
(actuator) 23, one or more bearing plates 24, and the bumper
pad 25.
[0048] In the
second embodiment shown in FIGS. 9 and 10, the
hydraulic cylinder 23 functions as the support tube.
Therefore, the support tube may be eliminated if a lighter
design is preferred. FIG. 9
is a side view of this second
embodiment of the hydraulic stinger shown in a retracted
posture whereas FIG. 10 shows this stinger in its extended
posture.
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[0049] METHOD OF ROCK BOLTING
NON] The foregoing rock bolter (or rock bolting system)
enables a novel method of rock bolting. This method comprises
independently extending the hydraulic stinger to engage (or
"sting") a rock face while the drill feed and bolting feed
remain retracted. While the hydraulic stinger is still
extended, i.e. still stinging the face, the method then
involves independently extending the drill feed. The hole is
then drilled in the rock with the hydraulic stinger engaging
(stinging) the rock face. Once drilling is complete, the
drill is withdrawn. The
system is indexed to rotate the
bolting feed into alignment with the hole. This is done with
the hydraulic stinger still engaging (stinging) the rock face.
The method then entails installing a rock bolt into the hole
using the bolting feed.
[0051] In one embodiment of this method, a flexible bolt
centralizer is used to guide the bolt. The bolt centralizer
is made of a flexible elastomeric material that is attached to
a sliding carriage for traveling over the rails of the bolting
feed. The bolt is advanced through the bolt centralizer until
the advancing bolting feed of the rock bolt causes the bolt
centralizer to fold flexibly into a substantially orthogonal
posture (as shown in FIG. 13) to permit the rock bolt to be
advanced all the way to the rock face.
[0052] The method may further involve installing a
replacement centralizer when the centralizer is damaged, loses
its elasticity or becomes worn out. The
detachable bolt
centralizer may be detachably mounted (e.g. fastened) to the
sliding carriage of the bolting feed via holes in a base of
the bolt centralizer.
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[NM In a
further embodiment, the method comprises mounting
a screen-gripping attachment to the hydraulic stinger,
gripping a screen with the screen-gripping attachment on the
stinger, placing the screen against a rock face by extending
the stinger and affixing the screen to the rock face. Gripping
the screen may be done by hydraulically extending a plurality
of finger extensions to grip the screen. This is
described
below in greater detail with reference to FIG. 15.
glom FLEXIBLE BOLT CENTRALIZER
[0055] Optionally, the rock bolter may include a novel
flexible bolt centralizer mounted on sliding carriage that
travels on rails of the bolting feed 40.
glow FIG. 11
is a front view of a flexible traveling bolt
centralizer 100 in accordance with an embodiment of the
present invention. FIG. 12 is a side view of the traveling
centralizer in its upright posture whereas FIG. 13 is a side
view of the traveling centralizer in its flexed or bent
posture. FIG. 14
is an isometric view of the traveling
centralizer in its upright posture.
[own As
depicted in FIGS. 11-14, the bolt centralizer has
a flexible body 102 capable of elastically flexing from an
upright posture (FIG. 12) to a folded, flexed or bent posture
(FIG. 13) which may be, in some embodiments, substantially
orthogonal to the upright posture. In the
upright posture,
the bolt centralizer centralizes or guides the rock bolt into
the drilled hole. In the flexed, bent or folded posture, the
bolt centralizer permits the bolting feed of the rock bolter
to pass by the centralizer. The flexure of the traveling bolt
centralizer is designed to bend or flex in response to the
force imposed on the centralizer by the bolting feed as it
advances.
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[0058] The
traveling centralizer 100 comprises a passage 104
for guiding the rock bolt into a hole drilled by the rock bolt
system. This
passage may be formed two finger-like members
106 or upwardly curving projections that may be spread apart
to receive the bolt. The
finger-like extensions are
elastically biased to return to the generally closed posture
shown in the figures. The
passage may define a generally
circular aperture to guide a rock bolt that has a generally
circular shaft. In the
illustrated embodiment, the finger-
like members are (at rest) spaced apart by a gap G that is
substantially smaller than a diameter D of the generally
circular aperture. Above
the gap G is a generally V-shaped
mouth 108.
(0059] The
traveling centralizer 100 includes a base 110 for
fastening the traveling centralizer to a sliding carriage
(shown in FIG. 18) that slides on the rails of the bolting
feed (as shown in FIGS. 20-24). As shown in FIGS. 11-14, the
base may include two lobes 112 (i.e. feet, pads, or flange-
like extensions) that contain holes 114 through which
fasteners are inserted to fasten the centralizer to the rail-
mounted carriage on the bolting feed. In variants, the number
of holes, the shape of the lobes and/or the placement of the
holes and lobes may be varied.
gmso] The centralizer may include a double concave body
profile 116 to facilitate bending of the centralizer from an
upright posture (FIG. 12) to a flexed, bent or orthogonal
posture (FIG. 13). The
double concave body profile includes
a front concavity 118 and a rear concavity 120. The front and
rear concavities may be symmetrical when the body is upright
and not flexed as shown in FIG. 12. Beneath
the double
concave profile is an archway 122 as shown in FIG. 11.
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[0061] In one
embodiment, the flexible body is elastomeric.
In one specific embodiment, the flexible body is made of
urethane although it will be appreciated that similar
materials may be substituted.
mu] To minimize wear and prolong service life, the
traveling bolt centralizer 100 may include a metal liner 124
in the passage. The
metal liner may be a steel or stainless
sleeve (or other suitable metal, alloy, or composite). This
sleeve may be detachably fastened to the centralizer so it can
be inspected, replaced, cleaned, serviced or repaired. For
example, the sleeve may be bolted, screwed or otherwise
fastened to the centralizer using fasteners.
[0063] As shown
in the embodiment depicted in FIG. 14, the
traveling bolt centralizer 100 has a base having two spaced-
apart holes that are substantially orthogonal to the passage.
The holes are designed to receive fasteners for fastening the
centralizer to the sliding carriage of FIG. 18 which is
designed to travel on the rails of the bolting feed.
p0641 SCREEN HANDLER
(0065] Optionally, the rock bolter may include a screen
handler in the form of a screen-gripping (or screen-handling)
attachment.
[0066] FIG. 15 is an isometric view of a screen-gripping
attachment 200 for mounting to an end of the hydraulic stinger
20 of the rock bolter 10. This screen-gripping attachment is
an accessory that may optionally be mounted to a distal
(working) end of the stinger to enable the stinger to grip (or
handle) screens. As is
known in the mining industry, wire
mesh screening is installed in mines as another form of ground
support, to prevent loose rocks from falling. As illustrated
in FIG. 15, the screen-gripping attachment 200 includes
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gripping members which may be in the form of screen-gripping
finger extension cylinders 210 and extension fingers 212.
These extension fingers 212 are hydraulically actuated by the
cylinders 210 to extend and engage a wire mesh screen. A
rotary actuator 220 is provided to rotate the screen. A
free-wheeling rotation housing 230 supports the rotary
actuator to permit the rotary actuator and the finger
extensions to rotate relative to the stinger. The
stinger
itself may extend and retract. With the rotary actuator 220,
the stinger is able to both translate and rotate the screen
gripped by the extensions fingers 212. The bolting feed may
be used to insert a bolt into the rock face to fasten the
screen in place while the stinger is holding the screen
against the rock face.
[0067] OPERATION OF ROCK BOLTER WITH FLEXIBLE CENTRALIZER
[0068] FIGS. 16
and 17 are side and rear views, respectively,
of the rock bolter 10 having two bolt centralizers 100, 150.
In the embodiment depicted in these figures, the rock bolter
includes both a flexible traveling centralizer 100 and a
flexible stationary centralizer 150 mounted to a forward end
41 of the rails 42 of the bolting feed 40.
[0069] FIG. 16
shows the hydraulic stinger 20 and its forward
bumper pad 25. The rock bolter 10 includes a feed extension
cylinder 28 and piston rod 29 for extending and retracting the
hydraulic stinger.
[0070] FIG. 16
also shows that the rock bolter 10 includes a
mounting frame 12 for mounting the rock bolter to a boom,
platform, or other such structure. The rock
bolter includes
a carousel 14, a turret 16, and an indexing mechanism 18.
[0071] The
drill feed 30 includes a rock drill 32 and drill
steel 33 that extends to the drill bit. The
drill bit is
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advanced by the drill feed to drill the hole in the rock face.
After indexing using the indexing mechanism, the bolting feed
40 then drives a bolt 45 into the hole that was drilled by the
drill bit of the drill feed. The bolt 45 may include a bolt
plate 46. The bolt plate 46 of the rock bolt is the end plate
(flange, washer or head) of the bolt that abuts the rock face
when the rock bolt is inserted into the hole.
[0072] As depicted in FIG. 17, the indexing mechanism 18
indexes the bolting feed into alignment with the drilled hole
by rotating the bolting feed about a center of rotation 35.
As depicted by way of example in FIG. 17, the center of
rotation 35 is offset relative to the two parallel axes of the
drill feed and the bolting feed, i.e. the center of rotation
lies between and below the drill feed 30 and the bolting feed
40 as shown in FIG. 17. The indexing mechanism 18 includes an
indexing cylinder 37 (i.e. a hydraulic actuator) that indexes
the drill feed and bolting feed by rotating the drill feed and
bolting feed about the center of rotation 35 such that the
bolting feed is moved into alignment with the hole drilled by
the drill feed.
(0073] FIG. 18
is an isometric view of the flexible traveling
centralizer 100 and its sliding carriage 130 that is adapted
to be mounted to the rails 42 of the bolting feed of the rock
bolter 10. The
flexible traveling centralizer 100, which may
be made of urethane or any other suitable elastomeric
material, rides on a sliding carriage that slides over the
rails of the bolting feed. As depicted by way of example in
FIG. 18, the sliding carriage may include a plurality of
spaced-apart threaded bores that align with the holes in the
base of the traveling centralizer, permitting threaded
fasteners to be inserted through the holes of the centralizer
and into the threaded bores in the carriage. The carriage may
include a wheel that rolls along a surface of the bolting feed
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as the carriage is advanced and retracted. By supporting at
least part of the weight of the carriage, the wheel helps to
provide a smoother motion for the carriage as it slides over
the rails. It will
be noted that the wheel rotates in the
space defined by the archway 122 introduced in FIG. 11.
(0074] FIG. 19
is an isometric view of the flexible traveling
centralizer 100 with a bolt 45 in the passage of the flexible
traveling centralizer. The flexible traveling centralizer
acts in concert with the flexible stationary centralizer to
provide a two-point support for the bolt 45 to guide the bolt
45 into the hole that has been drilled. As shown
in FIGS.
20-24, the flexible traveling centralizer 100 bends or folds
out of the way as the bolting feed 40 is advanced. Due to its
elasticity, the traveling centralizer 100 returns to its
original upright posture after the bolting feed 40 has been
retracted. Due to
its shape and material, the flexible
traveling centralizer 100 is able to undergo a large number of
bending-unbending cycles before it needs to be replaced.
P079 FIGS. 20-24 depict the operation of these flexible
centralizers 100, 150 as the bolting feed 40 is advanced on
its rails 42. FIG. 20
shows a rail-mounted bolting feed 40
having a traveling centralizer 100 mounted on rails 42 and a
stationary centralizer 150 mounted at a forward end 41 of the
rails 42. A bolt (not shown) extends from the bolt magazine
47 of the bolting feed 40. FIG. 21
shows how the traveling
centralizer 100 flexes as the bolting feed 40 advances on its
rails 42. FIG. 22 shows how the traveling centralizer 100 is
then completely bent/folded/flexed as the bolting feed passes
over top of the centralizer 100. FIG. 23
shows how the
forward stationary centralizer 150 also flexes as the bolting
feed 40 advances toward its maximum extension along the rails
42. It is
noteworthy that the stationary centralizer has a
different body structure than the traveling centralizer. The
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stationary centralizer has two legs with a wide stance that
spans the rails. However, the stationary centralizer has two
finger-like extensions that define a V-shaped mouth and a
passage for receiving the bolt, which may be similar to
finger-like extensions, V-shaped mouth and passage of the
traveling centralizer. FIG. 24 shows the forward centralizer
150 completely bent/folded when the bolting feed reaches its
maximum extension along the rails 42.
(0076] The
invention described above thus provides a number
of improvements in the realm of rock bolting. The
independently movable stinger, drill feed and bolting feed
greatly facilitate the task of installing rock bolts in a rock
face. The
stinger may furthermore be used, with a screen-
gripping attachment, to install protective screening. The
flexible centralizer provides a novel design for both the
traveling centralizer and the forward, stationary centralizer,
eliminating the need for complex centralizer mechanisms. Each
of these improvements facilitates, and renders more efficient,
the installation of rock bolts in a mine.
[0077] The
present invention has been described in terms of
specific embodiments, examples, implementations and
configurations which are intended to be exemplary or
illustrative only. Other variants, modifications, refinements
and applications of this innovative technology will become
readily apparent to those of ordinary skill in the art who
have had the benefit of reading this disclosure. Such
variants, modifications, refinements and applications fall
within the ambit and scope of the present invention.
Accordingly, the scope of the exclusive right sought by the
Applicant for the present invention is intended to be limited
solely by the appended claims and their legal equivalents.
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