Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02847567 2014-03-04
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AUXILIARY EQUIPMENT FOR USE WITH DRILLING APPARATUS
FIELD OF INVENTION
This invention relates to auxiliary equipment for use with drilling apparatus.
BACKGROUND TO INVENTION
The auxiliary equipment as herein envisaged, hereinafter referred to
specifically as an
auxiliary working apparatus, is provided particularly for use with a drilling
apparatus of
the type that is used in mines, for drilling holes into the ground. Such a
drilling apparatus
generally includes a support structure, for the stable support of the
apparatus in the
region where drilling is required, a drill motor mounted on the support
structure and a
drill pipe formed of a number of drill pipe sections, that is operatively
connected to an
output of the drill motor for the rotation thereof. Such a drilling apparatus
includes also a
displacement mechanism for displacing the drill motor and particularly the
drill pipe
connected thereto along a longitudinal axis of the drill pipe, for drilling
purposes, the
drilling operation usually including the insertion of extension segments in
line with the
drill pipe in order to permit drilling of "deep" holes. The support structure
also includes a
platform at a spaced location above the ground in which a hole is to be
drilled, the drill
pipe passing through a hole in the platform to permit the platform to
effectively form a
barrier between the operating parts of the drilling apparatus, i.e. the drill
motor and the
displacement mechanism, and the ground in which a hole is to be drilled.
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The above construction is important because a drilling operation provides for
the
displacement of compressed air along a passage defined through the drill pipe
to the
drilling segment that defines the drill pipe head, this head defining a larger
diameter than
the remainder of the drill pipe and thus providing for an annular space to be
formed in
the ground around the drill pipe where it has drilled a hole into the ground.
In addition to
the compressed air fulfilling a cooling function, it serves also to displace
soil displaced
by the drilling operation, commonly and hereinafter referred to as chippings,
from the
ground through the annular space. The chippings are effectively "blown" from
the
annular space by the compressed air. As such, and without the platform being
located
as described, the chippings will blow directly onto the operating parts of the
drilling
apparatus referred to and this clearly will result in unnecessary wear and
tear on these
parts, as the chippings are very abrasive.
The continuous displacement of soil from a hole being drilled, as described,
is important
insofar as clogging of the annular space with chippings will otherwise result,
thus
causing resistance to the rotation of the drill pipe and unnecessary strain on
the drill
motor. It has been found, however, that the chippings being "blown" from the
annular
space referred to, can also pass through the hole in the platform through
which the drill
pipe extends, thus potentially defeating the objective of the platform, which
is to protect
the operating parts of the drilling apparatus from the chippings. Still
further, chippings
blown from the annular space will tend to gather on the ground immediately
adjacent the
hole being drilled and on the platform immediately adjacent the hole through
which the
drill pipe extends, this gathering of the chippings resulting in "piles" of
chippings being
formed that will collapse from time to time and result in the chippings
dropping back into
the annular space. Clearly, for as long as air pressure is sufficient, these
chippings will
again be "blown" from the annular space, but particularly when air pressure is
insufficient or becomes insufficient due to the depth of the hole being
drilled, the
chippings dropping back into the annular space will result in this space
becoming
clogged, resulting in interference with the rotation of the drill pipe and
unnecessary load
being placed on the associated drill motor. In order to avoid motor damage, it
is then
required to reverse the direction of drill pipe displacement and then again to
provide for
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forward displacement, which can result in the chippings being released and
again being
blown from the annular space. This clearly will render a drilling operation
time inefficient.
It is thus an object of this invention to at least alleviate the above known
problems that
are associated with the use of a drilling apparatus of the type herein
envisaged.
W02007/122528 in the name of the present applicant discloses an auxiliary
working
apparatus for use with drilling apparatus of the abovementioned type. The
auxiliary
working apparatus includes a pair of roller-type brushes which are located on
opposite
sides of the drilling apparatus. The brushes have flexible bristles which
surround and
contact the drill pipe so as to trap and displace chippings away from the
drill pipe.
While effective to a degree, the brushes have been found to be unsatisfactory
in a
number of respects. Firstly, the applicant has found that the position of the
brushes at
two opposite sides of the drill pipe is inadequate to trap and displace
chippings which
emerge from the hole being drilled in an annular stream around the entire
circumference
of the drill pipe. In order to displace the annular stream of chippings away
from the drill
pipe, the brushes are sufficiently flexible to envelop and thereby contact the
drill pipe
causing wear and tear on the brushes and reducing the lifespan of the brushes.
Due to
the flexibility of the bristles of the brushes which is required in order to
contact and
envelope the drill pipe, in use, the centrifugal forces exerted by the brushes
on the
chippings are relatively small, resulting in the chippings being flung a
relatively short
distance from the hole being drilled. This causes a growing mound of chippings
to form
adjacent the hole, which must be removed at regular intervals so as to avoid
the mould
collapsing and the chippings falling back into the hole. Furthermore,
separator plates
are required in order to ensure separation of the chippings from the brushes.
This adds
to the expense associated with the use of brushes for displacing chippings
away from
the drill pipe.
It is an object of the present invention to ameliorate the abovementioned
problems
associated with the use of brushes as disclosed in W02007/122528.
Insofar as the auxiliary working apparatus of the present invention applies
particularly in
relation to the use of a drilling apparatus of the type envisaged above, any
reference
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hereinafter to a drilling apparatus must be interpreted as a reference to
drilling
apparatus particularly of the type hereinabove described.
SUMMARY OF INVENTION
According to the invention there is provided an auxiliary working apparatus
for use with a
drilling apparatus for drilling holes into the ground, the drilling apparatus
including a
support structure which is located on the ground and which includes a platform
which
forms a barrier at a spaced location above the ground on which the support
structure is
operatively positioned, a drill motor, a drill pipe displacement mechanism
supported by
the support structure operatively above the platform and a drill pipe
operatively
connected to the drill motor and extending through a hole in the platform to
be displaced
into the ground in which a hole is to be drilled, the auxiliary working
apparatus including,
in its operative configuration with respect to such a drilling apparatus,
an auxiliary support structure supported by the support structure of the
drilling apparatus
operatively beneath the platform of the drilling apparatus, the auxiliary
support structure
including a hub defining a central aperture through which the drill pipe
operatively
extends;
displacement means comprising a number of vanes which are mounted to the hub
of
the auxiliary support structure and which are operable to revolve around the
drill pipe
thereby to displace chippings which are displaced from a hole being drilled by
the drill
pipe, in use, to a location spaced from the hole; and
operating means for rotating the hub.
The vanes of the displacement means may extend radially outwardly from the hub
of the
auxiliary support structure. In one embodiment, the vanes may extend outwardly
along
radial axes intersecting a centre of the hub when the hub is viewed in top
plan view. In
another embodiment, the vanes may be mounted to the hub so as to extend
outwardly
at rake angles relative to said radial axes. More specifically, the vanes may
extend
operatively rearwardly relative to a direction of rotation of the hub.
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In a particular embodiment, the vanes may be in the form of panel elements.
More
specifically, the vanes may be in the form of flexible panel elements. Yet
more
specifically, the vanes may be in the form of rubber flaps.
The auxiliary support structure of the auxiliary working apparatus of the
invention
particularly may comprise a structure that can support the displacement means
in its
required operative configuration with respect to a drill pipe and a hole being
drilled by
the drill pipe, in use, of the drilling apparatus with which the auxiliary
working apparatus
is operatively used. Particularly for the support of the auxiliary support
structure of the
auxiliary working apparatus by the support structure of the associated
drilling apparatus,
the auxiliary working apparatus may include a set of elongate flexible
elements which
operatively support the auxiliary support structure in a suspended
configuration from the
support structure of the drilling apparatus. Such support can be conveniently
provided
for by a set of chains or cables, while it is envisaged also that this support
can be
provided for in many different configurations.
The operating means of the auxiliary working apparatus may include a coupling
arrangement for coupling the displacement means to a power output associated
with the
drilling apparatus. Alternatively, the operating means may include drive means
operatively connected to the displacement means for operating the displacement
means. More specifically, the operating means may include at least one
hydraulic motor
that can be driven by a hydraulic power supply and that is operatively
connected to the
hub for rotating the vanes. Clearly, the configuration of the operating means
is greatly
variable, being determined particularly by the mode of operation of the
displacement
means which is to be operated thereby.
The auxiliary working apparatus of the invention may comprise apparatus that
is
particularly adapted for use with a drilling apparatus for drilling holes into
the ground,
effectively serving as a dedicated chippings displacement apparatus for this
purpose.
It is envisaged still further that the auxiliary working apparatus of the
invention can be
provided as part of a drilling apparatus and, as such, the invention extends
also to such
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a drilling apparatus which includes an auxiliary working apparatus, in
accordance with
the invention, as part thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features of the auxiliary working apparatus of the invention and the
operation
thereof are described in more detail hereinafter with reference to an example
of such an
apparatus, which is illustrated in the accompanying diagrammatic drawings. In
the
drawings:
Figure 1 shows a partly sectional side view of an auxiliary working apparatus
in
accordance with the invention, mounted to a support structure of a drilling
apparatus for
drilling holes into the ground; and
Figure 2 shows a sectional side view of the auxiliary working apparatus of
Figure 1
mounted to a drilling apparatus, illustrating the manner in which chippings
are displaced
during a drilling operation;
Figure 3 shows a perspective view of the auxiliary working apparatus of Figure
1;
Figure 4 shows a side view of the auxiliary working apparatus of Figure 1; and
Figure 5 shows a bottom plan view of the auxiliary working apparatus of Figure
1.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring to the drawings, an auxiliary working apparatus for use with a
drilling
apparatus for drilling holes into the ground, in accordance with the
invention, is
designated generally by the reference numeral 10. The auxiliary working
apparatus 10
comprises, broadly, an auxiliary support structure 12 including a hub 14, a
number of
vanes 16 mounted to the hub and a hydraulic motor 18 for driving the hub.
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The auxiliary working apparatus 10 is configured for use with a drilling
apparatus
designated by the reference numeral 50, for drilling holes into the ground.
The drilling
apparatus 50 generally includes a support structure comprising a number of
upright
support columns 52 which are located on a ground surface 54 and a platform 56
which
is supported in a horizontal configuration by the support columns in an
arrangement
wherein the platform forms a barrier at a spaced location above the ground.
The drilling
apparatus further includes a drill motor (not shown), a drill pipe
displacement
mechanism (not shown) supported by the support columns and a drill pipe 58
which is
operatively connected to the drill motor which extends through a hole in the
platform 56
to be displaced into the ground in which a hole 53 is to be drilled. The drill
pipe defines
a central longitudinal passage 59 along which compressed air travels
downwardly along
the drill pipe. The drill pipe has an opening at its lower end through which
the air exits
the drill pipe into an annular space between the drill pipe and the side wall
of the drilled
hole.
The auxiliary working apparatus 10 is mounted to an operative underside of the
platform
56 by means of the auxiliary support structure 12 which also houses the
hydraulic motor
18. The hub 14 defines a central passage 20 within which the drill pipe 58 is
rotatably
received. The auxiliary support structure includes four circumferentially equi-
spaced
elongate support elements 17 which support the auxiliary support structure in
a
suspended configuration from the platform 56. More specifically, the support
elements
are pivotally connected at upper and lower ends thereof to the platform and
the hub,
respectively.
The vanes 16 are mounted to the hub 14 by means of mounting brackets 25 and
extend
radially outwardly therefrom. More specifically, the vanes are flexible rubber
panels in
the form of flaps. Each flap has a diagonally-extending strengthening rib 22.
With reference to Figure 5 of the drawings, the rubber flaps are
circumferentially spaced
and mounted to the hub 14 so as to extend outwardly at rake angles a of
between 10
and 30 defined between planes "X" extending through centres of flaps 16 and
radial
axes R which intersect at an axis of rotation P of the hub. More specifically,
the flaps
extend operatively rearwardly relative to a direction of rotation A of the
hub.
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During the use of the auxiliary working apparatus 10 and of the associated
drilling
apparatus 50, the flaps 16 revolve around the drill pipe 58 thereby displacing
chippings
which are blown from the hole 53 being drilled by the drill pipe 58, to a
location spaced
from the hole. As can be seen in Figure 2 of the drawings, an annular mound 26
of
chippings is formed around the hole 53 and spaced therefrom. In Figure 2,
arrows depict
the direction of travel of compressed air down the centre of the drill pipe
and thereafter
compressed air together with chippings entrained therein, up within the
annular space
surrounding the drill pipe and finally, the direction of travel of chippings
which are flung
outwardly by the rubber flaps. The rubber flaps contact the chippings as they
emerge
from the hole and displace the chippings operatively outwardly, i.e. as a
result of
centrifugal forces acting on the chippings, effectively flinging the chippings
outwardly to
a spaced location from the hole where the annular mound 26 of chippings is
formed and
where the chippings can be collected.
The fact that the chippings are displaced to a spaced location from the hole
being drilled
ensures that these chippings cannot again drop into the hole, this being a
problem
commonly associated with the drilling of holes in environments as envisaged
and
resulting in clogging of holes with chippings, particularly where the pressure
of the
compressed air provided to blow the chippings from the annular space defined
is no
longer sufficient, which can particularly occur also where very deep holes are
drilled. By
preventing such clogging, unnecessary loads on the drill motor is avoided,
while the
release of chippings from within the annular space, which would otherwise be
required
and which is associated with momentarily reversing the displacement of the
drill pipe,
also will not be required. This will ensure time efficiency associated with
the drilling of
holes which, without the auxiliary working apparatus, often is negatively
affected.
The rubber flaps which revolve around the drill pipe during a drilling
operation are
durable and effective in displacing the chippings an appreciable distance from
the drill
pipe. Furthermore, as the flaps revolve around the drill pipe, chippings
emerging from
entire circumference of the annular space surrounding the drill pipe are
displaced away
from the drill pipe. This provides for effective collection and removal of
chippings from
an area surrounding the entire circumference of the drill pipe. Furthermore,
as the flaps
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do not make contact with the drill pipe during operation, they are not
subjected to wear
and tear from contact with a drill pipe.
It will be understood that the auxiliary working apparatus 10 can be provided
as a
dedicated unit, i.e. a chipping displacement apparatus and that the apparatus
either can
be separately provided or provided as part of a drilling apparatus. When
provided as
part of a drilling apparatus, the invention extends clearly also to such a
drilling apparatus
which includes auxiliary working apparatus as described as part thereof.
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