Patent Description:
Mining operations and construction work commonly utilize drilling and blasting techniques. Usually, a plurality of boreholes need to be drilled into a rock surface. The boreholes extend a proper depth into the rock and are filled with explosive charges when drilling of all the holes is complete.

In the course of drilling prior to the filling with explosives, drill cuttings need to be removed from the drilled holes with the aid of a flushing medium such as compressed air or liquid. The liquid flush medium such as water may mix with the drill cuttings to form a clay paste. When a number of holes are drilled close together in a downwardly directed manner, the drill cuttings from a hole currently being drilled can block entrance to the already drilled holes nearby. The particularly affected are the lifter holes which are drilled along the floor of a tunnel for lifting the rock to floor level. The lifter holes may become buried and covered up completely by the drill cuttings and/or the clay paste thereof.

In the state of the art, an operator has to leave the relatively safe control station to manually locate and clean the entrance to every borehole while being exposed to the hazardous mining or construction environment. It is a long laborious process to find the buried borehole openings and subsequently clear them of the drill cuttings and/or the clay paste thereof, which impedes the progress of improving work efficiency and productivity.

The problem with drill cuttings may be avoided by the method disclosed in <CIT> or <CIT>. However, the process of installing pipes according to <CIT> or drilling line holes according to <CIT> would incur other problems while leaving the problem with drill cuttings unsolved.

<CIT> discloses a method of using a brush to remove drill cuttings from a borehole opening during drilling, wherein a rotary actuator is shared by the drill unit and the brush. However, the drill cuttings from a borehole currently being drilled can block entrance to the already drilled boreholes nearby. The method of <CIT> is not appropriate or efficient for clearing the blocked openings of already drilled boreholes.

<CIT> discloses a rotatable brush for removal of loose earth resting upon the blade of a boring member or an auger. The rotatable brush is positioned at one side of the blade and fixedly connected to the auger. The rotation of auger causes all portions of the auger blade upon which the loose earth rests to be presented to similarly timed rotative movement of the brush, and results in the removal of the loose earth away from the auger blade and the vicinity of the borehole in the ground. However, the brush is inappropriate for cleaning a lifter hole buried and covered up by tough drill cuttings and/or clay paste thereof.

There is a high demand for improved apparatus and method for clearing borehole openings which can solve the problem with drill cuttings in a straight-forward and efficient manner.

In view of the above, one object of the present disclosure is therefore to reduce manual workload and risks for personnel at the site during operations for clearing a borehole opening of blockages at entrance to the borehole.

Another object of the disclosure is to increase work efficiency and productivity.

Yet another object of the disclosure is to provide a novel and advantageous solution for clearing a borehole opening of blockages at entrance to the borehole.

Yet another object of the disclosure is to provide a robust and reliable solution for clearing a borehole opening of blockages at entrance to the borehole.

Yet another object of the disclosure is to provide an alternative solution for clearing a borehole opening of blockages at entrance to the borehole.

Yet another object of the disclosure is to improve mechanization and automation of clearing a borehole opening of blockages at entrance to the borehole.

The above mentioned objects are achieved according to a first aspect of the disclosure by a boom of a mining or construction work machine as specified in claim <NUM>, which boom comprising a first end connectable to the mining or construction work machine, a distal second end, and at least one sweeper assembly arranged at the distal second end of the boom. The sweeper assembly is configured to clear a borehole opening of blockages at entrance to the borehole. The boom as was described above enables mechanization and automation of the process of clearing a borehole opening of blockages at entrance to the borehole.

The sweeper assembly as was described above comprises at least one rotary actuator and/or at least one linear actuator. The at least one rotary actuator is used to transform energy to mechanical rotation of the sweeper assembly. The at least one linear actuator is used to move the sweeper assembly in a straight line.

The sweeper assembly as was described above further comprises at least one brush configured to rotate about an axis A. The rotating brush has the advantage of producing a continuous cleaning of a large area thereby increasing work efficiency and productivity.

The brush as was described above may comprise a rotatable shaft or drum. The rotary actuator as was described above controls mechanical rotation of the at least one brush via the shaft or drum.

The brush as was described above may further comprises a plurality of single- and/or multi-strand steel wire packs. The steel wire packs are wear-resistant such that the sweeper assembly can perform in an aggressive manner.

The sweeper assembly as was described above may comprises at least one scraping tool. The scraping tool has the advantage of providing a more focused cleaning which is particularly efficient for removing tough clay paste of drill cuttings from a borehole opening.

The sweeper assembly with at least one scraping tool may comprise at least one hydraulic cylinder configured to control operation of the at least one scraping tool. The hydraulic cylinder inherently produces linear motion of the at least one scraping tool. The above mentioned objects are also achieved according to a second aspect of the disclosure by a rig as specified in claim <NUM>, said rig comprising at least one boom as was described above. The rig has all the advantages that have been described above in conjunction with the boom and the sweeper assembly.

The above mentioned objects are also achieved according to a third aspect of the disclosure by a method of clearing a borehole opening of blockages at entrance to the borehole as specified in claim <NUM>, which method comprising the steps of positioning the sweeper assembly as was described at entrance to the borehole; and controlling operation of the at least one brush and/or the at least one scraping tool of the sweeper assembly as was described above to remove blockages from the borehole opening. The method has all the advantages that have been described above in conjunction with the boom and the sweeper assembly.

With reference to the appended drawings, below follows a more detailed description of embodiments of the disclosure cited as examples.

The present disclosure aims to reduce or even eliminate exposure of personnel to the hazardous work environment during operations for clearing a borehole opening of blockages at entrance to the borehole. The present disclosure further aims to reduce manual workload and increase work efficiency or productivity. The present disclosure improves mechanization and automation of the operations for clearing a borehole opening of blockages at entrance to the borehole by providing a novel, robust and reliable solution which is advantageous over the state of the art.

According to a first aspect of the disclosure, there is provided a boom <NUM> of a mining or construction work machine <NUM>, which boom <NUM> comprising a first end 4a connectable to the mining or construction work machine <NUM>, a distal second end 4b, and a sweeper assembly <NUM> arranged at the distal second end 4b of the boom <NUM>. The sweeper assembly <NUM> is configured to clear a borehole opening of blockages at entrance to the borehole. The boom <NUM> comprising the sweeper assembly <NUM> enables mechanization and automation of the process of clearing a borehole opening of blockages at entrance to the borehole. Furthermore, the sweeper assembly <NUM> is easy to operate.

The mining or construction work machine <NUM> may be a charging rig for loading boreholes with explosive charges. The charging rig <NUM> may comprise a mounting device <NUM> attached to the distal second end 4b of the at least one boom <NUM> (<FIG>), which mounting device <NUM> comprises a beam <NUM>, wherein the sweeper assembly <NUM> is arranged on the beam <NUM> (<FIG>). Other devices or tools, e.g. a loading assembly as was described in our patent application <CIT>, a hose for flushing medium, an explosive delivery hose, a hose handling unit, etc. may also be arranged on the same beam <NUM> of the charging rig <NUM> as the sweeper assembly <NUM>.

The sweeper assembly <NUM> may comprise at least one rotary actuator and/or at least one linear actuator.

The at least one rotary actuator is used to transform energy to mechanical rotation of the sweeper assembly <NUM>. The at least one rotary actuator may be hydraulically, pneumatically or electrically powered.

The at least one linear actuator is used to move the sweeper assembly <NUM> in a straight line. The at least one linear actuator may be hydraulically, pneumatically or electrically powered. The at least one linear actuator may be a hydraulic or pneumatic cylinder that inherently produces linear motion.

The sweeper assembly <NUM> may further comprise at least one brush <NUM> configured to rotate about an axis A (<FIG> and <FIG>). The rotating brush <NUM> has the advantage of producing a continuous cleaning of a large area thereby increasing work efficiency and productivity.

The sweeper assembly <NUM> may further comprise a connection means <NUM>, which connection means <NUM> connects the brush <NUM> to the distal second end 4b of the boom <NUM>. The connection means <NUM> may comprise an extendable first part with at least two telescopic sections <NUM>, <NUM> (<FIG>), wherein the first part is connectable to the distal second end 4b of the boom <NUM>; and a second part connectable to the brush <NUM>. A mining or construction work machine <NUM> may typically comprise a mounting device <NUM> attached to the distal second end 4b of the at least one boom <NUM> (<FIG>), which mounting device <NUM> comprises a beam <NUM>, wherein the connection means <NUM> of the sweeper assembly <NUM> connects the brush <NUM> to the beam <NUM> at the distal second end 4b of the boom <NUM> (<FIG>).

The connection means <NUM> comprising an extendable first part with at least two telescopic sections <NUM>, <NUM> provides the advantage of space-saving storage of the brush <NUM> when the sweeper assembly <NUM> is not in use and the advantage of flexibility in getting access to the area to be swept. Operation of the extendable first part of the connection means <NUM> may be controlled by a linear actuator.

The brush <NUM> as illustrated in <FIG> may comprise a rotatable shaft. The rotary actuator as was described above controls mechanical rotation of the at least one brush <NUM> via the shaft.

The brush <NUM> as illustrated in <FIG> may comprise a single-piece mounting flange <NUM>, wherein a plurality of single- and/or multi-strand wire packs <NUM> are mechanically affixed to the single-piece mounting flange <NUM>. Preferably, the wire packs <NUM> are made of wear-resistant material such as steel wires, which enables more aggressive performance of the sweeper assembly <NUM>.

The brush <NUM> as illustrated in <FIG> may comprise a rotatable drum <NUM> (<FIG> is a cross-sectional view of the brush <NUM> with a rotatable drum <NUM>. A cutting plane <NUM> indicated in <FIG> defines the cross-section shown in <FIG>. The rotary actuator as was described above controls mechanical rotation of the at least one brush <NUM> via the drum <NUM>.

The brush <NUM> as illustrated in <FIG> may comprise a plurality of single- and/or multi-strand wire packs <NUM> mechanically affixed to the drum <NUM>. Preferably, the wire packs <NUM> are made of wear-resistant material such as stainless steel, which enables aggressive performance of the sweeper assembly <NUM>.

The sweeper assembly <NUM> may comprise at least one scraping tool <NUM>. The scraping tool <NUM> has the advantage of providing a more focused cleaning which is particularly efficient for removing tough clay paste of drill cuttings from a borehole opening.

The sweeper assembly <NUM> may comprise at least one hydraulic cylinder <NUM> configured to control operation of the at least one scraping tool <NUM>. The hydraulic cylinder <NUM> inherently produces linear motion of the at least one scraping tool <NUM>.

The sweeper assembly <NUM> may comprise a connection means <NUM>, which connection means <NUM> comprising a shank <NUM> connected to the at least one scraping tool <NUM>, a pivot member <NUM> connecting the shank <NUM> to the distal second end 4b of the boom <NUM>, and a feeding device <NUM> arranged at the distal second end 4b of the boom <NUM>, wherein the feeding device <NUM> is connected to the shank <NUM>. The pivot member <NUM> enables rotary motion of the shank <NUM> around the pivot member <NUM> (<FIG>).

Typically, a mining or construction work machine <NUM> comprises a mounting device <NUM> attached to the distal second end 4b of the at least one boom <NUM> (<FIG>). The mounting device <NUM> comprises a beam <NUM>, wherein the shank <NUM> is connected to the beam <NUM> via the pivot member <NUM> at the distal second end 4b of the boom <NUM>, and wherein the feeding device <NUM> is attached to the beam <NUM> at the distal second end 4b of the boom <NUM> (<FIG>). The feeding device <NUM> is configured to move along the longitudinal axis of the beam <NUM>. Preferably, the feeding device <NUM> comprises an even number of rollers, which has the advantage of ensuring stable movement of the feeding device <NUM>.

The sweeper assembly <NUM> as illustrated in <FIG> may further comprise a first hydraulic cylinder <NUM> configured to control operation of the scraping tool <NUM>, a second hydraulic cylinder <NUM> configured to control operation of the shank <NUM>, and a third hydraulic cylinder <NUM> configured to control operation of the feeding device <NUM>.

The sweeper assembly <NUM> as was described above provides the advantage of space-saving storage of the scraping tool <NUM> when the sweeper assembly <NUM> is not in use and the advantage of flexibility in get access to the area to be cleaned.

According to a second aspect of the disclosure, there is provided a rig <NUM> comprising at least one boom <NUM> as was described above. The rig <NUM> may be a complex equipment intended for earth surface use or underground use. The rig <NUM> may be a mining or construction work machine adapted for various mining operations or construction work. The rig <NUM> may be a drilling rig adapted for drilling blasting holes, injection holes, holes for rock bolt reinforcement, etc.. The rig <NUM> may be a charging rig for loading boreholes with explosive charges.

<FIG> shows schematically a mining or construction work machine <NUM> comprising a carrier <NUM>, at least one boom <NUM> and a mounting device <NUM> attached to the distal second end 4b of the at least one boom <NUM>. Typically, the mounting device <NUM> comprises a beam <NUM> on which the sweeper assembly <NUM> may be arranged (<FIG> and <FIG>). Other devices or tools, e.g. a drilling machine, a loading assembly as was described in our patent application <CIT>, a hose for flushing medium, an explosive delivery hose, a hose handling unit, etc. may also be arranged on the same beam <NUM> as the sweeper assembly <NUM>. An enlarged view of the beam <NUM> with the sweeper assembly <NUM> is provided in <FIG> and <FIG>. The rig <NUM> has all the advantages that have been described above in conjunction with the boom <NUM> and the sweeper assembly <NUM>.

According to a third aspect of the disclosure, there is provided a method of clearing a borehole opening of blockages at entrance to the borehole, which method comprising the steps of positioning the sweeper assembly <NUM> as was described above at entrance to the borehole; and controlling operation of the at least one brush <NUM> and/or the at least one scraping tool <NUM> of the sweeper assembly <NUM> to remove blockages from the borehole opening. Optionally, the method further comprises a step of rinsing the swept borehole opening with water, which removes any residual debris from the entrance to the borehole. The method has all the advantages that have been described above in conjunction with the boom <NUM> and the sweeper assembly <NUM>.

The method as was described above for clearing a borehole opening of blockages at entrance to the borehole is a straightforward method which may be at least partially automatized.

Claim 1:
A boom (<NUM>) of a mining or construction work machine (<NUM>), which boom (<NUM>) comprising
a first end (4a) connectable to the mining or construction work machine (<NUM>),
a distal second end (4b), and
at least one sweeper assembly (<NUM>) arranged at the distal second end (4b) of the boom (<NUM>), wherein the sweeper assembly (<NUM>) is configured to clear a borehole opening of blockages at the
entrance to the borehole, and wherein the sweeper assembly (<NUM>) comprises at least one linear actuator configured to move the sweeper assembly (<NUM>) in a straight line.