BOLTING HEAD, BOLTING RIG AND METHOD

Description

RELATED APPLICATION DATA

This application claims priority under 35 U.S.C. § 119 to European Patent Application No. 24315041.4, filed on Feb. 6, 2024, which the entirety thereof is incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a bolting head for providing a rock surface with reinforcing rock bolts. The invention further relates to a bolting rig and to a method.

BACKGROUND

In mines, construction sites and at other work areas exists a need to reinforce rock surfaces and to thereby ensure their safety and suitability for the intended purposes. A common method for rock reinforcement is rock bolting. In such a reinforcement system several rock bolts are inserted into drilled drill holes and are tensioned. This way rock layers are bonded together so that the risk for collapse is reduced. Typically, the rock bolting is executed by means of a bolting rig having a bolting head for drilling the drill holes and for feeding the rock bolts inside the drill holes. However, the present bolting heads have been shown to contain some disadvantages.

SUMMARY

An object of the invention is to provide a novel and improved bolting head, bolting rig and method for reinforcing rock surfaces with rock bolts.

An idea of the disclosed solution is that in a bolting head there is at least one drilling unit and at least bolting unit mounted to a frame of the bolting head in parallel orientation relative to each other and they are also located at a lateral distance from each other. Further, the drilling unit and the bolting unit can operate simultaneously and without moving the drilling unit and the bolting unit in relation to the frame. This configuration allows simultaneous drilling and bolt feeding for the bolting head.

In other words, the drilling unit and the bolting unit are both continuously facing towards the rock surface during the operation and are independently and simultaneously operable to execute the drilling and the bolt insertion. Thus, the bolting head can execute the bolting without positioning movement between the drilling and bolt mounting. Therefore, the bolting head is without an indexing device or any other actuator for making the positioning movements between the drilling unit and the bolting unit.

An advantage of the disclosed solution is that when the drilling unit and the bolting unit operate simultaneously, significant time savings can be achieved in the rock reinforcing process. The rock bolting itself does not create any value for the mine, wherefore it is important to execute the reinforcing process as fast as possible so that actual value creating mining operations can be safely executed.

According to an embodiment, the bolting head includes a tensioning device for providing the rock bolt with pre-tension after being inserted into the drill hole. The tensioning device may include a rotation device for screwing a tensioning nut of the rock bolt.

According to an embodiment, the bolting head includes at least one bolt magazine arranged for storing several rock bolts. The bolt magazine is arranged parallel to the drilling unit and the bolting unit. In one embodiment an outer periphery of the bolt magazine has several storage places and the bolt magazine is rotatable around its longitudinal axis.

In an alternative embodiment the bolt magazine may be a linear magazine wherein several rock bolts are arranged in a linear configuration. Furthermore, possible other bolt magazine arrangements and structures can be implemented with the bolting head embodiments disclosed herein.

According to an embodiment, the frame of the bolting head has a rotating joint for mounting the bolting head to a boom whereby the bolting head is turnable in relation to the boom.

According to an embodiment, the lateral distance between the drilling unit and the bolting unit is set in accordance with a bolt distance of rock bolts to be mounted. In other words, the lateral distance is in accordance with a bolting plan defining the bolt distances.

According to an embodiment, relative positions between the frame, the drilling unit and the bolting unit are fixed. In other words, the relative positions of the drilling unit and the bolting unit are set by mechanical structure of the bolting head. Then, distance between the drilling unit and the bolting unit is determined already when designing and manufacturing the bolting head. This type of bolting head with the fixed configuration may be simple in structure, durable and inexpensive.

According to an embodiment, the lateral distance between the drilling unit and the bolting unit is adjustable whereby at least one of the drilling unit and the bolting unit is arranged laterally movably in relation to the frame. The drilling unit and the bolting unit are lockable to be laterally immovable when the bolting head is operating. In other words, the bolting head has a bolting feature and an adjusting feature, which are separate and not simultaneously operable.

According to an embodiment, the frame includes transverse guide surfaces along which the drilling unit, or the bolting unit, or both, can be moved in the transverse direction for adjusting their relative lateral position and distance. The adjusted position is locked by means of one or more locking or fastening elements for the duration of the bolting measures.

According to an embodiment, the adjusting movement is executed by means of manual adjusting elements, such as screw members or pulleys. Since the adjusting is not executed during a work cycle, implementation of the manual adjusting means is possible. Alternatively, there may be one or more adjusting actuators, such as hydraulic cylinders or motors for executing the adjusting movements.

According to an embodiment, the frame of the bolting head is a cradle on which the drilling unit and the bolting unit are mounted and wherein the cradle is an elongated object having transverse orientation in relation to the longitudinal axis of the parallel drilling unit and bolting unit. In other words, the cradle includes at least one fastening surface on which the drilling unit and the bolting unit are both mounted side by side at a later distance from each other.

According to an embodiment, the cradle is provided with a rotating joint by means of which the bolting head is mounted to a boom in a turnable manner.

According to an embodiment, the bolting head includes two drilling units and two bolting units, which are all simultaneously operable. In other words, the bolting head has totally four operating units executing bolting measures at the same time. This way the bolting process can be further enhanced and accelerated. Further, the great number of simultaneously operable units means less positioning movements of the bolting head.

According to an embodiment, the frame of the bolting head is a transverse cradle having two opposing sides. The two drilling units are arranged on the opposing sides and are facing away from each other. The same applies also for the two bolting units, which are arranged on the opposing sides and are facing away from each other. At one end of the cradle having an elongated configuration there is a rotating joint or a turnable coupling element for mounting the bolting head to a boom in a turnable manner.

According to an embodiment, the bolting head includes an anchoring element supportable against the rock surface. The frame of the bolting head can be turned in relation to the anchoring element. In other words, the anchoring element protrudes in the longitudinal direction of the bolting head and there is a turning joint and a turning actuator for turning the frame.

According to an embodiment, the anchoring element, the drilling unit and the bolting unit are mounted to the frame so that they form a triangle configuration.

According to an embodiment, the drilling unit and the bolting unit are located at a predetermined distance from each other, and further, a distance between the drilling unit and the anchoring element is equal to a distance between the bolting unit and the anchoring element. The configuration may be fixed, or the relative distances can be adjusted by executing adjusting movements before initiating the bolting work cycle.

According to an embodiment, the frame of the bolting head includes a first arm for connecting the drilling unit and the anchoring element to each other. A second arm is provided for connecting the bolting head and the anchoring element to each other.

According to an embodiment, the frame of the bolting head may alternatively be a cradle-like structure, which is configured to connect the drilling unit, the anchoring element, and the bolting unit to each other, and wherein the cradle-like structure is turnable in relation to the anchoring element. Thus, the frame may be without the separate arm members disclosed in the previous embodiment. The cradle may, for example, be a curved or angled elongated structure wherein the anchoring element is located at its middle part and wherein the drilling unit and the bolting unit are located at its opposite end parts.

According to an embodiment, the disclosed solution relates also to a bolting rig including a movable carrier; at least one boom mounted on the carrier; a bolting head mounted on the boom; and a control device for controlling operation of the bolting rig. The bolting head is in accordance with the features and embodiments disclosed in this document. Further, the control unit is configured to provide control commands to at least one drilling unit and to at least bolting unit of the bolting head mounted to one boom for executing a bolting work cycle comprising simultaneous drilling and bolting.

In other words, the control unit can control the bolting work cycle for executing bolting measures for two or more rock bolt positions at the same time. During a positioning phase the control unit can provide control commands for actuators moving the boom and the bolting head so as to position the bolting head to face towards rock bolt positions, i.e., towards planned but not yet drilled holes and towards already drilled holes at the planned locations. Thus, the bolting measures are not executed in front of one single rock bolt position but in front of several rock bolt positions whereby more efficient and quick bolting is possible.

According to an embodiment, the control unit executes the bolting work cycle automatically, or in assistance with an operator of the bolting rig. Then the control unit is provided with data on a bolting plan wherein at least a bolting pattern is defined. The bolting pattern includes data on relative distances of the rock bolts to be mounted.

According to an embodiment, an operator of the bolting rig may alternatively control the bolting cycle, whereby manual control is implemented. Then the operator may provide the control unit with needed control parameters and selections in a user interface and the control unit generates the control commands for actuators concerned.

According to an embodiment, it is possible to operate the bolting rig without a pre-planned bolting pattern input to a control unit. Then the control unit of the bolting rig can generate a bolting pattern in co-operation with an operator of the bolting rig and input parameters, such as bolt distances.

According to an embodiment, the disclosed solution relates also to a method of reinforcing a rock surface by means of rock bolts. The method comprises executing the reinforcing measures by means of a bolting rig including a bolting head mounted to a boom; drilling drill holes to the rock surface to be reinforced by means of a drilling unit of the bolting head; and mounting the rock bolts to the drill holes by means of a bolting unit of the bolting head. The method further includes executing by means of the bolting head simultaneous drilling and bolt mounting measures wherein the rock bolt is mounted to the at least one previously drilled drill hole and at the same time at least one new drill hole is drilled.

In other words, the method includes handling a yet undrilled drill hole and a previously drilled drill hole simultaneously. Thus, the implemented simultaneous drilling and bolting includes the drilling of the next drill hole simultaneously when the bolt mounting is executed to the previously drilled drill hole.

According to an embodiment, the method further includes keeping the drilling unit and the bolting unit at a predetermined lateral distance from each other and keeping their parallel orientation unchanged during the drilling and bolting measures. In other words, the bolting head is ready for simultaneous drilling and bolt feeding all the time without any indexing measures or additional positioning.

According to an embodiment, the method further includes providing the rock bolts to pre-planned rock bolt positions; and covering at least two rock bolt positions at a time and positioning the bolting head at the rock bolt positions in one go. In other words, in the disclosed solution the positioning is done with longer positioning steps ahead including several rock bolt positions, and not by executing the positioning one by one as in the known bolting methods.

According to an embodiment, the method further includes executing the reinforcing measures in accordance with a bolting plan with regular relative positions and distances between several rock bolt positions defined in the bolting plan.

In other words, the bolting plan being executed includes rock bolt positions having the same distance from each other. The lateral distance between the drilling unit and the bolting unit is set to correspond this regular distance. Further, the rock bolt positions can be arranged on straight lines, whereby the bolting pattern has geometrically simple configuration, whereby positioning movements of the bolting head are quick and simple.

According to an embodiment, the method further includes executing the reinforcing measures for a roof surface of an underground mine corridor.

According to an embodiment, the disclosed reinforcing measures are subjected to planar or flat rock surfaces, or to substantially flat rock surfaces.

According to an embodiment, the disclosed reinforcing measures are subjected to wall surfaces of an underground mine corridor.

According to an embodiment, the method further includes positioning the bolting head along a linear movement path in rows or columns.

According to an embodiment, the method further includes using a bolting head provided with an anchoring element, which forms a triangle configuration together with the drilling unit and the bolting unit; supporting the anchoring element against the rock surface at an anchoring position; executing square bolting for a square shaped rock bolt pattern defined by four rock bolt positions; and executing positioning movements of the bolting head by turning the drilling unit and the bolting unit simultaneously in relation to the anchoring element for positioning the drilling unit and the bolting unit to the rock bolt positions of the rock bolt pattern.

An advantage of the square bolting is that anchoring, i.e., positioning of the bolting head to the anchoring point, needs to be done only once for each square pattern. This way the positioning measures of the bolting head can be decreased whereby the bolting process can be quickened.

Alternatively, the square bolting pattern can be executed also differently. For example, two square patterns can be overlapping whereby the bolting head can be positioned with shorter positioning steps.

The above disclosed embodiments may be combined in order to form suitable solutions having those of the above features that are needed.

The foregoing summary, as well as the following detailed description of the embodiments, will be better understood when read in conjunction with the appended drawings. It should be understood that the embodiments depicted are not limited to the precise arrangements and instrumentalities shown.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are described in more detail in the accompanying drawings, in which

FIG. 1 is a schematic side view of a bolting rig executing simultaneous drilling and bolt feeding in a mine corridor.

FIG. 2 is a schematic top view of a bolting rig executing roof bolting.

FIGS. 3 and 4 are schematic views of a bolting head seen in longitudinal direction of a drilling unit and a bolting unit and which further illustrate a possibility to adjust their relative lateral distance.

FIG. 5 is a schematic view of the bolting head disclosed in FIGS. 3 and 4.

FIGS. 6-9 are schematic top views showing simultaneous drilling and bolting measures executed by means of the bolting head disclosed in FIGS. 3-5.

FIGS. 10 and 11 are schematic views of a bolting head having two drilling units and two bolting units.

FIGS. 12 and 13 are schematic top views showing simultaneous drilling and bolting measures executed by means of the bolting head disclosed in FIGS. 10 and 11.

FIGS. 14 and 15 are schematic views of a bolting head including an anchoring element around which a drilling unit and a bolting unit are turnable.

FIGS. 16-23 are schematic top views showing simultaneous drilling and bolting measures executed by means of the bolting head disclosed in FIGS. 14 and 15.

FIG. 24 is a schematic view of solution implementing a square bolting method with overlapping square patterns.

For the sake of clarity, the figures show some embodiments of the disclosed solution in a simplified manner. In the figures, like reference numerals identify like elements.

DETAILED DESCRIPTION

FIG. 1 discloses a bolting rig 1 having a movable carrier 2 and at least one boom 3 mounted on the carrier 2. A bolting head 4 is mounted on the boom 3. The bolting head 4 includes a drilling unit 5 for drilling drill holes 6 and a bolting unit 7 for inserting rock bolts 8 to the drill holes 6. The drilling unit 5 and the bolting unit 7 are arranged on the bolting head 4 in parallel orientation relative to each other and are both simultaneously operable. Drilling unit 5 can drill and at the same time the bolting unit can feed a rock bolt 8 to a previously drilled hole 6. When the drilling and rock bolt feeding are completed the bolting head 4 is positioned a step further so that the drilling unit 5 is at a next rock bolt position 9 and the bolting unit 7 is located at the previously drilled drill hole 6. Typically, the bolting head 4 can be positioned by means of the boom 3, and without moving the carrier 2, to several subsequent positions to execute the simultaneous drilling and bolting measures.

The bolting rig 1 also includes a control unit CU for controlling operation of the bolting rig 1. The control unit can provide control commands to the drilling unit 5 and to the bolting unit 7 for executing a bolting work cycle comprising simultaneous drilling and bolting. The control unit CU may also provide control commands for actuators for moving the boom 3 and the bolting head 4 in relation to the boom 3 and to thereby execute positioning movements for the bolting head 4. The control unit CU can provide automatic control, or it may assist an operator of the bolting rig 1. Further, the control unit CU may be provided with a bolting pattern wherein amount of rock bolt positions and distances therebetween are defined. When the disclosed solution is implemented, the distances between the rock bolt positions are equal and the bolting patterns have regular form.

The bolting may implement a roof bolting method wherein bolting is done to a roof surface 10 of a mine corridor 11 or gallery. The disclosed bolting arrangement is especially well suited to be used in bolting of roofs of low profile galleries. A mine implementing room and pillar mining method is one example of the low profile mine gallery where the disclosed bolting arrangement can be implemented. In low profile galleries a large number of rock bolt positions are defined in bolting plans and in typical cases the roof surfaces are relatively flat. The disclosed solution can also be applied to any other mine where the roof is flat, and the bolts are installed vertically.

Although in FIGS. 1-23 roof bolting is presented, but it should be appreciated that the disclosed bolting heads and operating principles can also be utilized for reinforcing wall surfaces or any other rock surfaces of mine galleries by providing them with a large number of rock bolts with parallel orientation.

FIG. 2 discloses an example of a regularly shaped bolting pattern 12 having several rock bolt positions 9 arranged in rows 13 and columns 14. The rock bolt positions 9 are arranged at equal distance from each other and form a kind of grid of rock bolt positions. The number of rows 13 and columns 14 depend for example on a size of a surface being reinforced. In FIG. 2 the bolting pattern 12 includes rock bolt positions 9, which can be reached by means of bolting head 4 without moving a carrier 2 of bolting rig 1.

The bolting head 4 is mounted to boom 3 and can be turned around a rotating joint 15 relative to the boom 3. The boom 3 can be moved in relation to the carrier 2 by means of one or more joints 16 and the length of the boom 3 is adjustable. Thereby, the boom 3 can provide the bolting head versatile positioning movements. The bolting head 4 includes drilling unit 5, bolting unit 7, and a bolt magazine 17, which are mounted to a frame 18 of the bolting head 4 in parallel configuration. When the bolting head 4 is positioned in accordance with the bolting pattern 12 and the bolting unit 7 is in alignment with an already drilled drill hole, then simultaneous drilling and bolt feeding can be initiated. No positioning movements or indexing is needed, but instead the two simultaneous operative bolting measures can be executed while the boom 3 and the frame 18 are static. The bolting unit 7 or the bolt magazine 17 may have manipulators, handling arms, or mechanisms for moving the rock bolts from the bolt magazine 17 to the bolting unit 7.

FIG. 3 discloses bolting head 4 wherein drilling unit 5 and bolting unit 7 are mounted to a frame 18 of the bolting head 4 in parallel orientation relative to each other and at a predetermined lateral distance D from each other. The distance D is set to correspond to distance between neighboring rock bolt positions of a bolting pattern. FIG. 4 shows that the distance D can be adjusted when another bolting pattern with different rock bolt distances is to be executed. During the actual bolting measures relative lateral positions of the drilling unit 5 and the bolting unit 7 are locked and no adjustment movements are executed. In FIGS. 3 and 4 the bolting unit 7 is adjusted in lateral direction, but alternatively the drilling unit 5 or they both can be adjusted. One further possibility is that the there is no adjusting feature but instead the relative position between the drilling unit 5 and bolting unit 7 is fixed.

FIGS. 3 and 4 further disclose that the frame 18 may be a cradle 19 including a fastening surface 27 on which the drilling unit 5 and the bolting unit 7 are mounted side by side at the lateral distance D from each other. The cradle 19 is an elongated object having transverse orientation in relation to longitudinal axis of the parallel drilling unit 5 and bolting unit 7. The cradle 19 is connected to a rotating joint 15 by means of which the bolting head 4 can be turned T in relation to a boom of a bolting rig.

FIG. 5 is an axonometric perspective view of the bolting head 4 shown in FIGS. 3 and 4. The drilling unit 5 includes a drilling feed beam 20 and a rock drilling machine 21 arranged movably on it. The rock drilling machine 21 has an impact device for providing a drilling tool 22 with impact pulses, and a rotating device for rotating the drilling tool 22 around drilling axis. The bolting unit 7 includes bolting feed beam 23 and a bolt feed device 24 that is arranged movably on the bolting feed beam 23. The bolt feed device 24 is capable of inserting the rock bolts 8 to drilled drill holes and may also include a tensioning device for providing the rock bolts with pre-tension after being inserted into the drill hole. The tensioning device may include a rotation device for screwing tensioning nuts 25 of the rock bolts 8.

FIGS. 6-9 disclose operation of the bolting head 4 shown in FIGS. 3-5. In FIG. 6 the bolting head 4 is positioned so that a first drill hole can be drilled to a rock bolt position located at a first row 13a and first column 14a of bolting pattern 12. The bolting head 4 can be turned relative to the rotating joint 15 to avoid collisions to possible wall structures or other obstacles. In the shown position, drilling unit 5 drills the initial first drill hole while the bolting unit 7 is not yet operating. When the drilling is completed, the bolting head 4 is repositioned to a next operational position shown in FIG. 7 by moving the boom 3 and the rotating joint 15. In this position the drilling unit 5 can drill a second drill hole on the first row 13a and the bolting unit 7 is aligned with the initial first drilled drill hole and can insert and pretension a first rock bolt. Simultaneous operation of the drilling unit 5 and the bolting unit 7 is implemented to enhance the bolting work cycle. It can also be considered that the bolting unit 4 is in alignment with the first row 13a and its drilling unit 5 and the bolting unit 7 are located at different columns 14a, 14b.

When the bolting measures are completed in the position shown in FIG. 7, the bolting head 4 can be moved further to a following operational position. The position movements can be relatively simple since they occur in alignment with the first row 13a. A control unit of the bolting rig can control execution of such positioning movements. When the positioning is ready, then the drilling unit 5 can drill again a new drill hole and the bolting unit 7 executes rock bolt feeding measures for the previously drilled drill hole.

FIG. 8 shows how the same operating procedure continues along the first row 13a. When the first row 13a is completed then a second row 13b can be operated in a similar manner.

However, it is possible to implement the disclosed bolting head 4 in an alternative manner and to proceed the bolting along columns 14 instead of rows 13. When operating along the columns 14, the bolting head 4 can be turned around the rotating joint 15 so that the drilling unit 5 and the bolting unit 7 are in alignment with the columns 14. Then the bolting head 4 is positioned step by step along the one column and when the column is completed, then the bolting head is positioned to a neighboring column and again the bolting measures are executed at each rock bolt position. The column type bolting principle is illustrated in a simplified manner in FIG. 9 by means of arrows 26a-26g.

FIG. 10 discloses a bolting head 4 including two drilling units 5a, 5b and two bolting units 7a, 7b. Then the bolting head 4 has a total of four operating units for executing bolting measures at the same time. Basic structure on the bolting head 4, the drilling units 5a, 5b and the bolting units 7a, 7b may correspond to the bolting head solution disclosed in the previous figures. However, the structure disclosed in FIG. 10 differs in that a cradle 19 serving as a frame 18 of the bolting head 4 has two opposing sides, which are now utilized as fastening surfaces 27a, 27b on which the drilling units 5a, 5b and the bolting units 7a, 7b are mounted. The two drilling units 5a, 5b are arranged on the opposing sides of the cradle 19 and are facing away from each other. The same applies also for the two bolting units 7a, 7b, which are arranged on the opposing sides of the cradle 19 and are facing away from each other. Further, in this alternative structure the rotating joint 15 is located at one end of the elongated cradle 19 so that the bolting head 4 can be turned T to a desired orientation in relation to a boom. There may also be bolt magazines 17a, 17b mounted to the opposing fastening sides 27a, 27b. Distance D between the drilling unit and the bolting unit may be fixed or it may be adjustable in accordance with a distance between rock bolt positions.

FIG. 11 is an axonometric perspective view of the bolting head 4 shown in FIG. 10. It can be noted that the drilling units 5a, 5b and the bolting units 7a, 7b are substantially similar as in the solution disclosed in FIG. 5. Therefore, no further description of their structure in required.

FIGS. 12 and 13 show that the bolting head 4 disclosed in previous FIGS. 10 and 11 can operate four rock bolt positions 9 at a time. FIGS. 12 and 13 show a situation wherein rock bolt positions on first row 13a are already drilled by means of the two drilling units 5a, 5b. Thereafter, the bolting head 4 is positioned to an operational position shown in FIG. 12 and can drill two more drill holes on a second row 13b and can simultaneously insert rock bolts to already drilled holes on the first row 13a. When drilling and bolt insertion is completed, the bolting head 4 is positioned further to a new operational position shown in FIG. 13. In the new operational position, the bolting head 4 covers again two already drilled holes on the first row 13a and two rock bolt positions not yet been drilled on the second row 13b. In FIGS. 12 and 13 the bolting head 4 is positioned in row direction RD but it is also possible to make the position movements in column direction CD. FIG. 13 further illustrates that four rock bolt positions of the bolting pattern 12 can be considered to form squares 28 and each of such squares 28 can represent on operational position for the bolting head 4.

FIG. 14 discloses a bolting head 4 including anchoring element 29, which can be supported against a rock surface. Frame 18 of the bolting head 4 can be turned T in relation to the anchoring element 29. The anchoring element 29 may protrude in the longitudinal direction of the bolting head 4 so that it contacts the rock surface first when positioning the bolting head to an anchoring point. There is a turning joint 30 between the anchoring element 29 and the frame 18. A turning actuator (not visible) is provided for turning the frame 18, drilling unit 5 and bolting unit 7 mounted to the frame at the anchoring point. The anchoring element 29, the drilling unit 5 and the bolting unit 7 are arranged so that they form a triangle configuration, which is illustrated by means of a triangle 31. The drilling unit 5 and the bolting unit 7 are located at a predetermined distance from each other. Further, the distance between the drilling unit 5 and the anchoring element 29 is equal to distance between the bolting unit 7 and the anchoring element 29.

In FIG. 14 an angle between the drilling unit 5 and the bolting unit 7 is fixed, but it may alternatively be adjustable so that distance between the drilling unit 5 and the bolting unit 7 can be shortened or lengthened and to thereby allow implementation of the same bolting head for handling bolting patterns with different rock bolt distances.

Located between the drilling unit 5 and the bolting unit 7 is a bolt magazine 17, which may be of any type.

FIG. 15 is an axonometric perspective view of the bolting head 4 shown in FIG. 14. It can be seen that the drilling unit 5 and the bolting unit 7 may be substantially similar as in the previously presented solutions. Therefore, there is no need to disclose their structure in detailed.

FIGS. 16-23 disclose operation of the bolting head 4 disclosed in FIGS. 14 and 15.

In FIG. 16 bolting measures are initiated by positioning the bolting head 4 at a first auxiliary point 32a and using therein the drilling unit 5 for drilling a first drill hole on a first row 13a. Thus, the anchoring element 29 anchors the bolting head 4 to the first auxiliary point 32a while the initial drill hole is drilled. In this preparatory phase the bolting unit 7 is not operated.

In FIG. 17 the bolting head 4 is positioned so that the anchoring element 29 is at a first anchoring point 33a, which is located at a point of intersection of diagonals 34 of a first square pattern 35a defined by four rock bolt positions 9. The drilling unit 5 drills a first drill hole on a second row 13b and the bolting unit 7 inserts a rock bolt to the initially drilled drill hole on the first row 13a.

In FIG. 18 the bolting head 4 is turned around the anchoring element 29 and a second drill hole is drilled on the second row 13b while a rock bolt is inserted to the first already drilled hole on the second row 13b.

In FIG. 19 the bolting head 4 is turned further clockwise whereby a second drill hole can be drilled on the first row 13a and bolting can be executed to the second drill hole on the second row 13b.

In FIG. 20 the anchoring element 29 of the bolting head 4 is positioned to a second auxiliary point 32b so that the bolting head 7 can insert a rock bolt to a last drill hole of the first square pattern 35a. In that position the drilling unit 5 can drill a first drill hole for a second square pattern 35b.

In FIG. 21 the bolting head 4 is positioned to a second anchoring point 33b, which is located at a point of intersection of diagonals of a second square pattern 35b. Then rock bolt can be inserted to a first drill hole of the second pattern 35b and the following drill hole can be drilled to a third rock bolt position on the second row 13b. As can be seen in FIGS. 22 and 23 the bolting process of the second square pattern 35b continues in similar way as in the first square pattern 35a. When drilling of a new drill hole and bolt insertion to a previously drilled drill hole are completed, the bolting head is turned around the anchoring element 29 so that all the rock bolt positions 9 of the second square pattern 35b are handled.

In FIG. 23 it is disclosed that a third auxiliary anchoring point 32c is needed to bolt the last drill hole of the second square pattern 35b and to drill a first drill hole for a following third square pattern 35c. A third anchoring point 33c is implemented for positioning the bolting head 4 so that the drill hole positions 9 of the third square pattern can be processed.

The movements of the bolting head at the anchoring points 33 from one hole to another can be automated. As the movements are rotation movements around the anchoring points 33, it is easy to achieve great accuracy of the position of the bolting head. Thus, it is easy to align a rock bolt from the bolting unit to the previously drilled drill hole.

Alternatively, if the movement is not automated, assisting components can be added to help an operator to position the bolting head at the right location, and especially to position the bolting unit in front on the drill hole that was made by the drilling unit previously. These components can be, for example, lasers, cameras, probes, or any other components.

FIG. 24 illustrates a further possibility to implement the above disclosed bolting head with the anchoring element and the square patterns covering four rock bolt positions 9. The solution shown in FIG. 24 implements overlapping square patterns 35 and 36. There are additional anchoring points 37 of square patterns 36 in addition to the anchoring points 33 of the square patterns 36. Another way to consider this is that the bolting head 4 is positioned further in shorted steps as compared to the positioning steps presented in previous FIGS. 16-23. Then there is a need only to a first auxiliary point 32 at the beginning of the bolting process.

Although the present embodiment(s) has been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present embodiment(s) be limited not by the specific disclosure herein, but only by the appended claims.