Note: Descriptions are shown in the official language in which they were submitted.
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The invention relates to a method and apparatus for manually
positioning an elongated rock drilling apparatus to a desired direction, where-
in the elongated rock drilling apparatus is swingably carried by a boom, and
the boom is turnably and/or swingably mounted on a support. The invention
relates further to an arrangement for carrying out the method.
During drilling it is important that the rock drilling apparatus
can be positioned correctly to desired positions in simple manner. In tun-
nelling as well as bench blasting it is also of great importance that holes
drilled side by side are parallel with each other.
Constructions for automatic positioning of a rock drilling apparatus
to different drilling positions as well as for parallel displacemen~ thereof
between different drilling positions are previously known. In the United
States Patent No. 3,896,885 there is disclosed means for automatic positioning
and/or parallel displacing of a rock drilling apparatus. In this disclosure,
means are provided for automatic positioning of the rock drilling apparatus to
a given bearing and to a given angle wi~h respect to the vertical line. In ~ -
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United States Patent No. 3,481,409 there is disclosed a drill boom having a
self-correcting electro-hydraulic angular positioning servo system for
parallel displacement of the rock drilling apparatus between different dril-
ling positions. Drill booms are also known having solely hydraulic or solelymechanical parallel motion means.
It is an object of the present invention to provide a simplified
system for indicating the angles of a boom and an elongated rock drilling
apparatus carried thereby. For instance, when exchanging a drill bit only
the rock drilling apparatus need be tilted, and after the exchange it must be
possible to bring the rock drilling apparatus back exactly to its previous ~ ;
position. In drilling of parallel holes it must be possible to move the rock
drilling ~pparatus out of its parallel position~ for instance when drilling
contour holes, and then bring the rock drilling apparatus back to conformity
with the direction of the parallel holes.
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The invention provides a method of posit:ioning an elongated boom-
mounted rock drilling apparatus to a desired drilling direction, relative
to a fixed support7 comprising: swinging the elongated rock drilling
apparatus relative to the boom by power means about a first axis~ said boom
carrying said rock drilling apparatus,swinging or turning said boom about a
second axis relative to said fixed support by power means~ said fixed
support carrying said boom, the desired drilling direction being defined by
the turning angle of the elongated rock drilling apparatus about said first
and second axes, said first and second axes being perpendicular to one
another~ setting by means of actuator means set values of the turning angle
of the elongated rock drilling apparatus about each of said first and second
perpendicular axes relative to said fixed support~ sensing by means of angle
sensitive ~eans the actual values of the turning angle of the elongated rock
drilling apparatus about each of said first and second perpendicular axes
relative to said fixed support~ forming error signals from the differences
between the sensed actual values of the turning angles and the respective
set value, indicating said error signals visually, and swinging or turning
manually said elongated rock drilling apparatus or boom until the sensed
actual values of the turning angles coincide with the respective set valueO
From another aspectg the invention provides a boom arrangement for
positioning an elongated rock drilling apparatus to a desired drilling
direction relative to a fixed support, comprising: a boom pivotally mounted
on the fixed support about a first pivot axis~ power means for pivoting said
boom about said first pivot axis~ an elongated rock drilling apparatus
pivotally mounted on said boom about a second pivot axis, said boom
pivotally moving said elongated rock drilling apparatus relative to said
fixed support about a further pivot axis which is perpendicular to at least
one of said first and second axes, setting means for setting set values of the
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turning angles of the elongated rock drilling apparatus about said perpendi-
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cular ~xes relativ~ to said fixed support, sensing means for sensing the
actual values of the turning angles of the elongated rock drilling apparatus
about said perpendicular axes relative to said fixed support, means
associated with said setting means and said sensing means for forming error
signals corresponding to the differences between the sensed actual values of
the turning angles and the respective set values, and means for visual
indication of said error signals.
The system can be used as a complement to booms having conventional
parallel motion means. In these booms, there are geometric and/or hydraulic
faults. Improved accuracy when moving the boom can be obtained by the
invention. In hydraulic parallel motion it often occurs that the operator
unintentionally mo~es the rock drilling apparatus out of its right position.
Adjustment of the rock drilling apparatus back to this position is a time-
consuming ~nexact operation. l~hen using the present system as a complement
to the hydraulic parallel motion, such unintentional deviation from the
correct direction causes ~ problems. The boom is provided with manual
positioning means superior to the ~arallel motion meana~ The manual
positioning means can be operated to position the apparatus manually in such
a manner that the set values coincide with the respective actual values to
enable correction of d~viations from exact parallelism caused by geometric
and/or hydraulic faults.
The above and other~purposes of the invention will become obvious
from the following description and from the accompanying drawings in which
two embodiments are shown by way of example. It should be understood that
these embodiments are only illustrative of the invention and that various
modifications thereof may be made within the scope of the claims following
hereinafterO
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In the drawings, Figure 1 shows a side view of a drill boom accord-
ing to the invention.
Figure 2 shows in section an enlarged view of an angle sensitive
device for sensing the swing angles of the drill boom about vertical pivot
shaftsO
Figure 3 shows the mounting of a device for setting the set values
of the side angles.
Figure 4 shows diagrammatically the system for indicating the side
angle and the vertical angle of the drill boom.
Figure 5 shows a top view of another embodiment of a drill boom
according to the invention.
The drill boom 10 in Figure 1 co]nprises a jib boom 11 which at its
ends is pivoted to intermediate pieces 14, 15 over horizontal pivot means or
pivot shafts 12~ 13. The intermediate piece 14 forms part of a drill boom
support 170 The opposite intermediate piece 15 carries a conventional feed
bar 20. On the feed bar 20 is slidably guided a rock drilling machine 22,
which is fed by power for instance by means of a feed screw and a feed motor
23 therefor. In the claims, the feed bar 20 and the rock drilling machine 22
are referred to as an elongated rock drilling apparatusO
Across th~ horizontal pivo~ 12 of the boom support 17 is pivotally
coupled a hydraulic el~evation angle ram 24 which extends between the inter-
mediate portion of ~he jib boom 11 and the lower end of the intermediate
piece 14. By extension or contraction of the hydraulic ram 24 the elevation
angle of the jib boom 11 can be adjusted relative to the boom support 17 about
the pivo~ 12. A hydraulic elevation angle ram 25 is also pivotally coupled
across the horizon~al pivot 13 of the feed bar 20 extending from an intermed-
iate portion of the jib boom 11 to the intermediate piece 15. By extension
or contraction of the hydraulic ram 25 the elevation angle of the intermediate
piece and thus also of the feed bar can be adjusted relative to the jib boom
11 about the pivot 130
At opposite side of the jib boom 11 with respect to the hydraulic
elevation angle ram 24 is pivotally coupled a hydraulic pilot ram 28
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extending from an intermediate portion of the Jib boom 11 to the upper end of
the intermediate piece 1l~. The hydraulic ram 28 is chosen equal in size with
the hydraulic angle ram 25 and the geometric relations between its pivot
points and the pivot 12 are made equal with the corresponding arrangement of
the pivot points of the hydraulic ram 25 with respect to the pivot 13. The
hydraulic ram 25 is slave coupled with the hydraulic pilot ram 28 over a
hydraulic vertical adJustment circuit. The vertical ad~ustment circuit com-
prises hydraulic passages which connect the opposite cylinder chambers of the
hydraulic pilot ram 28 with the cylinder chambers of corresponding volume in
the hydraulic ram 25. At the connections of the hydraulic eleva-tion angle
ram 25 there are inserted in said passages conventional hydraulic locks of
check valve type.
The intermediate piece 14 is by means of a vertical pivot means or -
pivot shaft 16 pivoted to the boom support 17. By means of a lateral arm
the intermediate piece 14 is pivotally coupled to a hydraulic side angle ram
27 which is fixed at a pivot point on the boom support 17. By extension or
contraction of the hydraulic side angle ram 27 is performed a side swing of
the jib boom 11 and an adjustment of its side angle at the pivot 16. The
intermediate piece 15 at the outer end of the jib boom 11 is pivoted to a
bracket 19 by means of a vertical pivot means r pivot shaft 18, the bracket
19 providing a guide for the feed bar 20 for the adjustment thereof in
longitudinal direction by the aid of a hydraulic feed displacing ram 21.
Across the vertical pivot 18 is pivotally coupled a hydraulic side angle ram
26 between the intermediate piece 15 and the bracket 19. By extension or
contraction of the hydraulic side angle ram 26 the side angle of the feed
bar can be adjusted about the pivot lo. The hydraulic ram 26 is slave coupled
to a pilot hydraulic ram 29 of identical size. The pilot hydraulic ram is
pivotally coupled across the vertical pivot 16 between the boom support 17
and a lateral arm on the intermediate piece 14 opposite to the hydraulic side
3 angle ram 27. A detailed description of the drill boom and its positioning
to different drilling positions is to be found in our Canadian Patent
No. 886,975.
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Figure Z shows in section -the mounting of an angle sensitive device
for sensing the side angle of the jib boom ll relative to the boom support 17.
The intermediate piece 14 is attached to the tubular pivot 160 The intermed-
iate piece 14 and the pivot 16 are turnablyjournalled in the boom support 17
by means of bushings 30, 31. An end plate 32 is attached to the boom support
170 The end plate 32 carries a cup-shaped holder 33. In the holder 33 is an
inductive angle sensitive device 39 mounted. The device 39 is protected by
a cover 35. Another cup-~shaped holder 36 is attached to the tubular pivot 16.
The shaft of the device 39 is conn0.cted with the bottom of the holder 36 via
a flexible metallic bellows 370 The angle sensitive device 39, which consists
of a synchro in the embodiment shown by way of example, transmits in known
manner a signal~ the amplitude andsign of which represent the turning of the
shaft of the synchro, and thus the turning of the jib boom 11 relative to the
boom support 170 In the same manner is a Synchro 40 connected to the pivot 18
for determining the turning of the bracket 19 relative to the jib boom 11.
A vertical angle sensitive device 38 is attached to the bracket l9o .-
The device 38 may be of any suitable type. One type of vertical angle sensi-
tive devices is shown in the United States Patent No. 3 113 283. In the pres-
ent embodiment, however, the vertical angle sensitive device consists of a
synchro of the same type as the side angle sensitive devices, wherea~ a pendulum
is mounted on the shaft of the synchroO
The system for indicating the side angles and the vertical angle,
Figure 3 comprises the synchros 393 40 and a synchro 41 for setting the set
value of the side angle of the desired drilling direction relative to a refer-
ence directionO There is also an electronics central which comprises an
oscillator 4~ for generating a suitable supply voltage to the synchros, about
6 V, 700HzD The oscillator 42 is supplied with 24 V DC from an accumulatorO
A phase de~ector 43 is provided for phase detection of the summed signal from
the synchros 39, 40, 41. The reference input of the phase detector 43 is
supplied with the output voltage of the oscillator 430 The summed signal from
side angle sensitive synchros 39, 40, 41 is transmitted from the rotor winding
of the synchro 40 and the signal input of the detector 43 is supplied with
this sur~med signal. From the output of' the detector 43 there is obtained a
smoothed direct-current voltage, which illustrates the amplitude and sign of
the divergence from the sum angle O . The angular divergence is supplied to
an indicating instrument 45 which shows linearily the divergence within for
instance ~10 .
The set value of the vertical angle of the desired drilling direction
is set by means of a synchro 47. The summed signal from the synchro 47 and
the vertical angle sensitive device 38 is supplied to the signal input of a
phase detector 44. From the output of the detector 44 there is obtained a
smoothed direct-current voltage, whichshowsthe amplitude and sign o~ the
divergence from the sum angle O . The angular divergence is supplied to an
indicator instrument 46 which shows linearily the divergence.
In a preferred embodiment of the invention the reference direction
in the horizontal plane is the direction of tunnelling or drifting. The
correction angle between the direction of the supporting frame, which carries
the boom support 17, and the reference direction is set by means of an
operating knob 48, Figure 3, which is connected with the synchro 41 via a
chain, not shown. The desired drilling angle relative to the direction of
tunnelling is set by means of an operating knob 49~ which is mounted on the
shaft of the synchro 41. The turning angle of the knob 48 can be read on a
scale 51. The turning angle of the knob 49 and the shaft of the elgon 41
relative to the elgon 41 can be read on a scale 50.
In Figure 5, another embodiment of a drill boom according to the
invention is shown. For the sake of simplicity, corresponding members in
Figures 1 and 5 are given the same reference numerals. By means of a
diagrammatically indicated turning device 52 the boom support 17 is turnable
360 about a geometric polar axis 53 which traverses the centre line of a
shaft 54 incorporated in the turning device 52. A more detailed description
of the drill boom is to be found in the Canadian Patent 989,815.
Angle sensitive devices 39, 40 are connected to the pivots 16~ 18.
A vertical angle sensitive device 38 is connected to the shaft 54 and shows
the turning of the shaft 5ll about the polar axis 53. The feed bar 20 is
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swingable in ~ plane which traverses the polar axis 53. By means of the angle
sensitive devices 39, 40 a signal is obtained which represents the position of
the feed bar 20 in this plane. The vertical angle sensitive device 38 shows
the turning of said plane about the polar axis 53. l'he set values of respec-
tively the position of the feed bar in said plane and the turning angle of
- said plane are set by means of synchros 41 and 47 respectively. The angle
sensitive devices for the actual values and the set values are connected as
shown in Figure 4 and the difference between corresponding actual and set
values is indicated by means of pointer instruments 45, 46.
The invention may of course be applied in other types of drill booms,
such as booms comprising several pivotally connected members.
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