TECHNICAL FIELD

The present invention relates to rock bolting, for example within the mining industry and when performing tunnel construction. The invention particularly concerns a nozzle, a system and a method for securing a bolt in a rock hole.

BACKGROUND

In conjunction with tunneling or in mining the rock may weaken which in turn may lead to parts of the rock collapsing. A collapsed rock will not only delay the work at the site but is also very hazardous for personnel working on the site. There is thus a need for measures which reduces the risk of collapse. Such measures are usually called rock reinforcement. Wood pillars and wood beams were used for a long time but have given way to better solutions. A common method for rock reinforcement today is to use bolts for fixating a rock arc that will carry the ceiling in the tunnel. The bolt may e.g. be fastened in a pre-drilled hole or may be drilled into the rock during the fastening procedure.

However, when the underground opening is large, bolts may not be long enough to create the arc effect. Instead cable bolts may be used. The cable bolts may e.g. be steel cables. These cables are fastened in the rock hole by a grouting agent, e.g. cement. The cables may also be fastened by mechanical anchor, e.g. an expanding shell in the top of the cable for instant support. The cables fastened this way are thereafter grouted in order to achieve rust protection by encapsulation. Traditionally the cable bolts were placed in pre-drilled holes and the hole was thereafter filled with grout. This is a method which is still commonly used in mines, even though it carries a lot of risk since it is a manual operation requiring the presence of personnel close to parts of the rock that are not secured.

During the last decades a mechanized operation has been developed. The hole is first drilled and thereafter filled with grout. The cable bolt is inserted into the hole as the final step. The mechanized method is not only faster compared to the previous method, but it is also much safer as the entire process is controlled from the cabin where the operator is protected. Typically, all of the operations, such as e.g. drilling, mixing and pumping of grout, cable insertion etc., is performed by one machine and one operator. Unfortunately, the mechanized method of cable bolting has some limitations and drawbacks of its own. The grouted cable cannot carry loads until the grout is cured. The grout which is usually cement takes a few hours to cure, but full load carrying capability is only achieved after approximately 48 hours. Thus, the method is good for secondary support, but not for primary support since the waiting time will delay the work.

Furthermore, the grout need to be mixed by a mixing system, usually provided on the rig. One batch of grout will require around 15 minutes for mixing. Since many customers prefer to first drill all of the bolt holes in the tunnel and thereafter perform the bolting, the time required to mix the grout will limit the productivity considerably. In addition, the grout system requires a lot of cleaning in order to function satisfactorily. The rig often has an automatic cleaning program installed but the grout pump and mixer still needs manual cleaning to operate well. This cleaning may often require up to one hour per work-shift, thus reducing the overall productivity.

NO 319141 B1 discloses a method of reinforcing a rock by rock bolting. The bolt is secured in the rock hole by pumping a multi-component fast hardening resin into a rock hole. The components are mixed in a mixer before entering the rock hole.

WO 2017180042 A1 discloses a method for rock reinforcement where a first and a second component are injected into a rock hole through a first and a second channel for securing a bolt in the rock hole. A blocking agent is thereafter injected into the second channel.

In view of the existing prior art there is thus a need to improve the methods, devices and systems used today when performing cable bolting in order to achieve a fast and reliable cable bolting procedure.

SUMMARY

An object of the present invention is therefore to improve the reliability and efficiency of the operation when performing rock cable bolting. An object is furthermore to reduce the risks for personnel at the site during operation. Alternatively, the object is to achieve an alternative to known solutions within the technical field.

The object is achieved according to a first aspect of the invention by a nozzle for injecting a multi-component mixture into a rock hole, wherein the mixture is adapted for securing a bolt in the rock hole. The nozzle comprising a first channel adapted to receive a first component of the multi-component mixture, a second channel adapted to receive a second component of the multi-component mixture and a third channel adapted to receive a blocking agent. The third channel is connected to the first channel such that the blocking agent can be provided to the first channel via the third channel. Furthermore, the nozzle comprises a mixing member adapted to mix the first and the second component prior to injecting the mixture of the first and the second component into the rock hole. The nozzle further comprises an outlet at a first end of the nozzle adapted to inject the mixture of the first and the second component directly into the rock hole.

The bolt may e.g. be a cable bolt.

The nozzle may be adapted to be inserted into a rock hole and fill the hole from the bottom of the hole with the multi-component mixture. The nozzle may then be moved out of the hole as the hole is being filled with mixture thereby filling the hole from the bottom and out towards the hole entrance.

The third channel may be connected directly to the first channel.

By the nozzle comprising a first and a second channel adapted to receive a respective component and a mixing member adapted to mix the first and the second component prior to injecting the mixture into the rock hole it is ensured that the components do not mix before the mixing member. Thereby the risk of blockage in the system is reduced. Furthermore, since the nozzle is adapted to inject the mixture directly into the rock hole the mixture will be mixed just before leaving the nozzle and being injected in the rock hole, e.g. into the bottom of the rock hole. Thereby there is no risk of the components curing before leaving the nozzle and entering the rock hole. At the same time a proper mixing of the components is ensured since the nozzle comprises a mixing member arranged to mix the components. The components thereby need not mix inside the hole, i.e. within the hole outside of the nozzle, which may result in inadequate mixing of the components resulting in a decreased quality of the mixture that is intended to secure the bolt in the rock. Furthermore, since the nozzle is adapted to inject the mixture directly into the rock hole the mixture may be injected into the bottom of the hole, ensuring that the hole is filled properly and evenly. Furthermore, the operation of injecting the mixture into the hole is much facilitated since the nozzle is adapted for direct injection into the rock hole, whereby no auxiliary equipment such as external mixers etc. are needed. In addition, since the nozzle comprises a third channel adapted to receive a blocking agent which is connected to the first channel such that the blocking agent can be provided to the first channel via the third channel, a blocking agent may be provided to the first channel. The blocking agent may thereby extrude the first component from the first channel and replace the first component in the first channel with blocking agent. The blocking agent will provide a barrier in the first channel. The first channel will then be blocked from coming into contact with e.g. moisture and/or the second component. The first component is thereby held separate from moisture and/or the second component in the first channel thanks to the blocking agent constituting the barrier. Thereby the first channel is protected from e.g. coatings in the channel which may be created when the first component cures upon contact with for example moisture and/or upon contact with the second component. As a result thereof, the risk for a stop or blockage in the first channel is reduced. Thus, the risk for interruption during rock reinforcement operation is decreased and as a

consequence the reliability and the efficiency of the rock reinforcement process are improved.

Consequently, a nozzle for injecting a multi-component mixture into a rock hole is provided that achieves the above mentioned object.

According to some embodiments the third channel is connected to the second channel such that blocking agent can be provided to the second channel via the third channel.

The third channel may be connected directly to the second channel.

Since the blocking agent can be provided to the second channel via the third channel the blocking agent may be provided to the second channel. The blocking agent may thereby extrude the second component from the second channel and replace the second component in the second channel with blocking agent. The blocking agent will thereby provide a barrier in the second channel. The same advantages will then be achieved in the second channel as was achieved in the first channel above. Specifically, the second channel will then be blocked from coming into contact with e.g. moisture and/or the first component. The second channel will then be protected from any coating build up in the same way as the first channel. Additionally, by being able to introduce blocking agent into the second channel a redundancy is achieved whereby if the blocking agent for some reason does not reach the first channel, the second channel will still be blocked by the blocking agent preventing the first and second component from coming into contact with each other. This increases the reliability of the nozzle further, improving the reliability and efficiency of the process of bolting.

According to some embodiments the nozzle comprises a fourth channel adapted to receive the blocking agent, wherein the fourth channel is connected to the second channel such that the blocking agent can be provided to the second channel via the fourth channel.

The fourth channel may be connected directly to the second channel.

By having a fourth channel adapted to receive the blocking agent which is connected to the second channel blocking agent may be provided to the second channel via the fourth channel. Thereby the blocking agent may be provided to the first and the second channel through separate channels. This adds redundancy to the nozzle since if the third or the fourth channel would malfunction, e.g. by being blocked, blocking agent will still reach one of the first or second channels and thereby ensure that the components wont mix with each other or with moisture in that channel.

According to some of these embodiments the third channel is connected to the first channel upstream of the mixing member and wherein the fourth channel is connected to the second channel upstream of the mixing member. With upstream of is herein meant upstream relative to the intended flow direction of the components or the blocking agent within the channels.

Since the third and fourth channel is connected to the first and second channel upstream of the mixing member respectively, the blocking agent will be provided into the channels before the mixing member. Since the components are intended to be mixed in the mixing member there is a greater risk that the components or mixture of the components moves from the mixing member backwards through the nozzle into the channels. By connecting the channels upstream of the mixing member, the blocking agent will extrude the components through the mixing member. Furthermore, the blocking agent will also provide a barrier for the mixture and the components in the mixing member, preventing them from moving towards and into the channels. Furthermore, the blocking agent may be provided into the mixing member via the channels, thereby extruding the components and any potential mixture still in the mixing member from the mixing member. Thereby no mixture that could cure and block the mixing member will remain in the mixing member. Thus, the risk of blockage in the mixing member is reduced.

According to some embodiments herein the first and the second channel are connected upstream of the mixing member.

By connecting the first and the second channel upstream of the mixing member, the first and the second component will meet before entering the mixing member. Thereby they will mix somewhat before being mixed properly in the mixing member which improves the mixing and thereby the final mixture providing a more reliable final product.

According to some embodiments herein the nozzle comprises a non-return valve in each channel.

Alternatively, only some of the channels comprise a non-return valve, such as e.g. one of the channels, two of the channels or three of the channels.

By providing a non-return valve in each channel it is ensured that no component or blocking agent flow backwards in the system. This reduces the risk that blockages due to coating or build-up of hardened components or blocking agent are created within the channels or the system. Thereby the risk of malfunction is reduced which minimizes the number of operational stops needed. Thereby the reliability and the efficiency of the rock reinforcement process are improved.

According to some embodiments herein the nozzle has an elongated shape.

Since the nozzle is elongate it is easy to move within a narrow rock hole. Thereby the nozzle is better suited to inject the multi-component mixture directly into the rock hole since the nozzle may be moved within the hole and e.g. placed in the bottom of the rock hole and thereby start filling the hole from the bottom. Thus, since the nozzle is elongate it may be placed in the bottom of the rock hole and thereafter be moved out of the rock hole as it is injecting mixture into the hole. The maneuverability is furthermore much increased, improving the efficiency of the process since the risk of the nozzle getting stuck in the rock hole is reduced. According to some embodiments the nozzle comprises a groove on the outer surface of the nozzle arranged to receive a sealing package. The sealing package may have a size which is larger than the groove such that it sticks out beyond the outer surface of the nozzle.

By providing a sealing package in a groove in the outer surface of the nozzle mixture and/or blocking agent is prevented from flowing over the nozzle during injection of the mixture into the rock hole. If the mixture flows over the nozzle the nozzle will be covered by the mixture which may make the disassembling process harder as the mixture may harden on top of the nozzle. Furthermore, component mixture on the nozzle may hinder the movement of the nozzle within the rock hole. The nozzle may even get stuck in the hole in this case. Thus, by providing the sealing package in a groove on the outer surface of the nozzle the process of injecting the mixture into the rock hole is facilitated. According to some embodiments the nozzle comprises a respective inlet for each of the channels at a second end of the nozzle opposite the first end of the nozzle and where each of the inlets comprises a connection means for connecting a line to the respective inlet. Each of the inlets comprises a connection means for connecting a line to the respective inlet wherein the channels are completely arranged within the outer walls of the nozzle.

Since the nozzle comprises inlets for each of the channels at a second end opposite of the first end, with connection means for connecting a line to the respective inlet the lines carrying the components and/or the blocking agent may extend in the same direction as the nozzle. Thereby the nozzle will not have any sections or components extending substantially in the transversal direction out of the nozzle which could hinder the movement of the nozzle within narrow rock holes. Thus, the inlets and the connections do not extend outside of the outer diameter of the nozzle, ensuring that the nozzle is adapted for injecting mixture directly into the rock hole by not being bulky and taking up much space in the transversal direction. The nozzle will thereby be further adapted to inject the mixture directly into the rock hole, specifically into the bottom of the rock hole, without the need of any auxiliary equipment for that purpose. Furthermore, the

maneuverability of the nozzle will be improved. According to some embodiments herein the nozzle is adapted to cooperate with a feeding device capable of moving the nozzle in and out of the rock hole.

By being adapted to cooperate with a feeding device capable of moving the nozzle in and out of the rock hole the nozzle may be moved into the rock hole and out again. Thereby the nozzle may inject the mixture into the bottom of the rock hole and while the hole fills up steadily be moved out of the hole. Furthermore, by adapting the nozzle to cooperate with a feeding device the moving of the nozzle is much facilitated.

The above mentioned object is also achieved according to a second aspect of the invention by a system for injecting a multi-component mixture into a rock hole, wherein the mixture is adapted for securing a bolt in the rock hole. The system comprises a nozzle for injecting a multi-component mixture into a rock hole, wherein the mixture is adapted for securing a bolt in the rock hole. The nozzle comprising a first channel adapted to receive a first component of the multi-component mixture, a second channel adapted to receive a second component of the multi-component mixture and a third channel adapted to receive a blocking agent. The third channel is connected to the first channel such that the blocking agent can be provided to the first channel via the third channel. Furthermore, the nozzle comprises a mixing member adapted to mix the first and the second component prior to injecting the mixture of the first and the second component into the rock hole. The nozzle further comprises an outlet at a first end of the nozzle adapted to inject the mixture of the first and the second component directly into the rock hole. The system further comprises a feeding device capable of moving the nozzle relative to the system.

By the system comprising the nozzle having all the advantages that have been described above and a feeding device capable of moving the nozzle relative to the system, a system is achieved that can perform rock bolting in an efficient and reliable manner. Furthermore, since the system performs the bolting, the process is mechanized. Thereby no personnel need to be in areas under the rock that are not secured. Thus, the risk for personnel is reduced.

Consequently, a system for securing a bolt in a rock hole is provided that achieves the above mentioned object. According to some embodiments herein, the feeding device may be adapted to move the nozzle by interacting with at least one line connected to the nozzle.

The at least one line may be arranged within an outer package. The feeding device is then arranged to interact with the outer package in order to move the nozzle.

The feeding device may comprise four feed rollers adapted to move the nozzle.

Since the feeding device is adapted to move the nozzle by interacting with at least one line connected to the nozzle, and by implication the nozzle being adapted to be moved by the feeding device in such a way, no extra equipment is needed to move the nozzle. Thus, a simple and robust way of moving the nozzle is achieved with few components which may break down. Furthermore, the cost of the nozzle is reduced since the lines providing the components and the blocking agent can be reused for the purpose of moving the nozzle.

By arranging the at least one line within an outer package several advantages are achieved. First, the outer package may be made of a tough material which protects the lines during operation which increases the reliability of the system and decreases the risk of failure during operation. Furthermore, the outer package may exhibit characteristics which facilitate the movement of the nozzle by the feeding device. For example, the outer package may be made of a material which is flexible enough to bend somewhat but still rigid enough to support the weight of the nozzle when being moved into a rock hole. An additional advantage is that the lines may be collected and do not hang loosely independently of each other with the risk of entangling. Thus, the risk of tangling of hoses is decreased which also decreases the risk of operational stops. Thus, the efficiency of the rock bolting process is improved, as well as the reliability of the process.

Since the feeding device comprises four feed rollers adapted to move the nozzle a robust movement of the feeding device is achieved. Since the nozzle may be relatively heavy it is advantageous to use several feed rollers. Furthermore, by using four feed rollers a stable configuration is achieved which is advantageous when moving the nozzle via the lines connected to the nozzle.

According to some embodiments herein, the system comprises a first line connected to a source of a first component and a second line connected to a source of a second component. According to some embodiments the third channel of the nozzle is connected to the second channel of the nozzle such that blocking agent can be provided to the second channel via the third channel.

Alternatively, according to some embodiments the nozzle may comprise a fourth channel adapted to receive the blocking agent. The fourth channel is then connected to the second channel such that the blocking agent can be provided to the second channel via the fourth channel.

According to some embodiments the system furthermore comprises a third and a fourth line connected to a source of a blocking agent. The first, second, third and fourth lines are further connected to the first, second, third and fourth channel of the nozzle respectively.

In this case the lines connecting the nozzle and the sources may be arranged within the outer package described above.

The system may further comprise a winding member for supporting the lines in a winding manner and which winding member allow the lines to unwind as the nozzle is moved relative to the system.

The lines may e.g. be hoses, tubes, flexible pipes, a multichannel hose containing several lines etc. Since each channel in the nozzle is connected to a source of a respective component or blocking agent via a respective line, the components of the mixture as well as the blocking agent may be arranged at a distance from the nozzle. Furthermore, by using lines the movement of the nozzle relative to the system and the sources of the fluids is much facilitated. Thereby the nozzle may in an easy and reliable manner be moved into the rock hole while still being connected to the sources of the mixture components and the blocking agent. The need to move the system is thus decreased since the nozzle will be connected to the sources of the mixture component and the blocking agent even when moved quite far from the system itself. Thus, the reliability and maneuverability of the system and nozzle is improved.

By arranging the lines connecting the nozzle with the sources of components and/or blocking agent within an outer package all of the advantages described above in conjunction with the at least one line are achieved.

Since the system comprises a winding member which supports the lines and allows the lines to unwind the risk of the lines getting stuck in equipment, the rock hole or each other is reduced. Furthermore, by being able to wind the lines on the winding member the feeding device is assisted when moving the nozzle out of the rock hole since there will be no line build-up behind the feeding device. Thus, the movement of the nozzle relative to the system is much facilitated by the winding member. The above mentioned object is also achieved according to a third aspect of the invention by a method for injecting a multi-component mixture into a rock hole, wherein the mixture is adapted for securing a bolt in the rock hole.

The method comprises to place a nozzle into the bottom of a rock hole. The nozzle comprises a first channel adapted to receive a first component of the multi-component mixture, a second channel adapted to receive a second component of the multi- component mixture and a third channel adapted to receive a blocking agent. The third channel is connected to the first channel such that the blocking agent can be provided to the first channel via the third channel. Furthermore, the nozzle comprises a mixing member adapted to mix the first and the second component prior to injecting the mixture of the first and the second component into the rock hole. The nozzle further comprises an outlet at a first end of the nozzle adapted to inject the mixture of the first and the second component directly into the rock hole.

The method further comprises to inject a multi-component mixture into the rock hole by providing a first and a second component of the multi-component mixture into the first and the second channel of the nozzle respectively.

The method further comprises to provide a blocking agent into the first and/or second channel of the nozzle.

Furthermore, the method comprises to, while injecting the multi-component mixture into the rock hole, continuously move the nozzle out of the rock hole by retracting the nozzle from the bottom of the hole towards the entry of the hole.

By performing this method, using the nozzle with all of the advantages described above, an efficient and reliable method of securing a bolt in a rock hole is achieved. The method may e.g. be performed by the system described above. By placing the nozzle in the bottom of the rock hole and continuously moving the nozzle out of the rock hole as the rock hole is being filled with the multi-component mixture it is ensured that the rock hole is filled with well-mixed mixture from the bottom in a homogenous manner. Thus, there is no risk that the mixture is not well-mixed or that the rock hole is filled heterogeneously which could lead to an inadequate fastening of the bolt. Furthermore, the process can be performed rapidly and in a mechanized manner which reduces the risk of personnel. Consequently, a method for securing a bolt in a rock hole is provided that achieves the above mentioned object. According to some embodiments the method further comprises to insert a bolt into the rock hole.

The step of inserting the bolt into the rock hole may be performed after the nozzle has been completely removed from the rock hole. By inserting a bolt into the rock hole the rock hole is reinforced. By inserting the bolt after the nozzle has been completely removed from the rock hole it is ensured that the nozzle will not obstruct the bolt when inserting the bolt. Furthermore, by ensuring that the nozzle has been completely removed it is also ensured that the rock hole has been adequately filled before inserting the bolt. Thus, a more reliable method of securing a bolt is achieved.

According to some embodiments the step of providing the blocking agent is performed just before the nozzle has been completely removed from the rock hole. By pumping the blocking agent into the nozzle to extrude unmixed component just before the nozzle has been completely removed from the rock hole it is ensured that no blocking agent and/or unmixed component ends up on the ground outside the hole. This is advantageous since unmixed component may be a health hazard. By avoiding that the component ends up on the ground outside the rock hole the risk of any personnel being affected by potentially hazardous agents is minimized. Thus, a more reliable method of securing a bolt in a rock hole is achieved.

According to some embodiments the method further comprises, after the step of inserting the bolt into the rock hole, performing a post insertion treatment of the bolt, wherein the post insertion treatment comprises one or more out of vibrating the bolt, pulsating the bolt and rotating the bolt.

By causing the bolt to rotate, pulsate and/or vibrate inside the rock hole a better adherence of mixture to the bolt is achieved since the mixture inside the rock hole may fill out any nooks or crannies of the bolt. This advantageous effect may be even more pronounced when the bolt is a cable bolt. If the bolt comprises bulbs these may be filled by the mixture during this procedure, thereby increasing the adherence of mixture to the cable. Thus, thereby a more reliable and efficient method of securing a bolt in a rock hole is achieved.

The vibration may be performed in the axial direction of the bolt. The process of vibrating the bolt may comprise to continuously move the bolt back and forth in the axial direction of the bolt over a distance of 1-10 mm, preferably 1-5 mm, most preferably 1-2 mm.

The pulsation may be performed in the axial direction of the bolt. The process of pulsating the bolt may comprise to continuously move the bolt back and forth in the axial direction of the bolt over a distance of 50-200 mm, preferably 50-150 mm, most preferably 80-120 mm. A typical distance may e.g. be 100 mm.

The rotation may be performed by rotating the bolt around an axis of rotation which coincides with the longitudinal axis of the bolt.

The above mentioned object is also achieved according to a fourth aspect of the invention by a rig adapted to secure a bolt in a rock hole comprising a system where the system comprises a nozzle for injecting a multi-component mixture into a rock hole, and the mixture is adapted for securing a bolt in the rock hole. The nozzle comprises a first channel adapted to receive a first component of the multi-component mixture, a second channel adapted to receive a second component of the multi-component mixture and a third channel adapted to receive a blocking agent. The third channel is connected to the first channel such that the blocking agent can be provided to the first channel via the third channel. Furthermore, the nozzle comprises a mixing member adapted to mix the first and the second component prior to injecting the mixture of the first and the second component into the rock hole. The nozzle further comprises an outlet at a first end of the nozzle adapted to inject the mixture of the first and the second component directly into the rock hole. The system further comprises a feeding device capable of moving the nozzle relative to the system.

The rig may be used in mining and/or construction application for rock

reinforcement purposes.

Since the rig has all the advantages that have been described above in

conjunction with the nozzle, system and method, a rig is achieved that can perform rock bolting in an efficient and reliable manner. Furthermore, since the rig is adapted for securing a bolt in a rock hole the act of reinforcing the rock is facilitated and improved since the rig may move the system to new rock sites thus providing flexibility and efficiency to the process.

Consequently, a rig adapted for securing a bolt in a rock hole is provided that achieves the above mentioned object.

The above mentioned object is also achieved according to a fifth aspect of the invention by a computer program product comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method as was described above.

The above mentioned object is also achieved according to a sixth aspect of the invention by a computer-readable storage medium storing a computer program product comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method as was described above.

The method for securing a bolt in the rock hole is mechanized and automatized by means of a computer program. Thereby no personnel need to be in areas under the rock that are not secured, which reduces or even eliminates the risk for personnel.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional objects and advantages to, as well as features of, the invention will be apparent from the following detailed description of one or several embodiments provided with reference to the accompanying drawings, in which:

Fig. 1 shows a system arranged on a rig,

Fig. 2a shows a nozzle in a perspective view,

Fig. 2b shows the nozzle in an exploded view,

Fig. 2c shows a connection plate from a top view,

Fig. 2d shows the connection plate in a perspective view,

Fig. 3a shows a third element of the nozzle in a perspective view,

Fig. 3b shows the third element of the nozzle from a top view,

Fig. 3c shows a cross-section of the third element of the nozzle,

Fig. 4a shows a second element of the nozzle in a perspective view, Fig. 4b shows the second element of the nozzle from a top view,

Fig. 4c shows the second element of the nozzle from a side view,

Fig. 4d shows a cross-section of the second element of the nozzle,

Fig. 5a shows a first element of the nozzle in two perspective views,

Fig. 5b shows a cross-section of the first element of the nozzle,

Fig. 5c shows a cross-section of the first element of the nozzle,

Fig. 5d shows the first element of the nozzle from a bottom view as seen in the direction of the inlets of the nozzle,

Fig. 5e shows the first element of the nozzle from a top view as seen in the direction opposite the inlets of the nozzle,

Fig. 6a shows the nozzle in an assembled state in a side view,

Fig. 6b shows a cross-section of the nozzle in an assembled state,

Fig. 7a shows a cross-section of the nozzle in an assembled state,

Fig. 7b shows the nozzle in an assembled state in a side view,

Fig. 8a shows a winding member, a feeding device and the nozzle in a perspective view, Fig. 8b shows the nozzle and an outer package containing lines connected to the nozzle in a perspective view,

Fig. 8c shows the outer package in an exploded view,

Fig. 9a shows the feeding device from a top view,

Fig. 9b shows a cross-section of the outer package containing four lines, and

Fig. 10 shows a flow chart illustrating a method for securing a cable bolt in a rock hole.

DETAILED DESCRIPTION

The invention will now be described in more detail below with reference to the accompanying drawings, in which example embodiments are shown. The invention should not be construed as limited by the disclosed examples of embodiments; instead it is defined by the appended claims. Like numbers in the figures refer to like elements throughout. Fig. 1 illustrates a system 1 for injecting a multi-component mixture into a rock hole, wherein the mixture is adapted for securing a bolt in the rock hole. According to a preferred embodiment, the bolt is a cable bolt. In Fig. 1 the system 1 is arranged on a rig 3. The system 1 comprises a nozzle 5 adapted for injecting a multi-component mixture into a rock hole. In Fig. 1 the nozzle 5 is arranged on a front part of the rig 3. The system may further comprise a feeding device 7 capable of moving the nozzle 5 relative to the system 1 and/or the rig 3, e.g. in and out of a rock hole. The feeding device 7 is in Fig. 1 arranged on a crane 8. The feeding device 7 can thereby be positioned independently from any drilling unit (not shown in Fig. 1) arranged on the rig 3. A number of lines 9 are connected between the nozzle 5 and tanks 6A, 6B arranged on the rig 3 in order to allow a fluid medium to be transported from the tanks 6A, 6B to the nozzle 5. A winding member 10 is also arranged on the rig 3. The winding member is arranged to support the lines 9 in a winding manner and allows the lines 9 to unwind or wind up onto the winding member 10 as the nozzle 5 is moved relative to the system 1.

The nozzle 5 according to an embodiment of the invention will now be described in greater detail with reference to Fig. 2-7. Fig. 2a illustrates the nozzle 5 in an assembled state and Fig. 2b illustrates the nozzle 5 in a disassembled state or exploded view. As was described above, the nozzle 5 is adapted to inject a multi-component mixture into a rock hole. The nozzle 5 may comprise a first element 11 , a second element 13 and a third element 15. The first 11 , second 13 and third 15 elements may be arranged with complementary features in order to easily be assembled into the complete nozzle 5. The nozzle 5 may have a cylindrical shape. The nozzle 5 may be elongate in order to easily fit into narrow rock holes.

Fig. 3a-c illustrates the third element 15 according to embodiments herein in greater detail. The third element 15 may have a substantially cylindrical shape and taper towards a first end 22 of the nozzle 5. Thus, the third element 15 may comprise a first section 35 and a second section 36. The first section 35 may be cylindrical and the second section 36 may be frustoconical. The third element 15 may be adapted to be connected to the second element 13. For this purpose, the third element 15 may comprise a first inner space 31’ and a second inner space 33’. The shape of the first inner space 3T and the second inner space 33’ may be adapted to interact with complementary shapes of the second element 13 such that part of the second element 13 may be received in parts of the third element 15. To this end the first inner space 3T may be adapted to receive a second part 42 of the second element 13 which can be seen in Fig. 4a-d. Furthermore, the second inner space 33’ may be adapted to receive a first part 41 of the second element 13. The first inner space 3T may thus exhibit a complementary shape to the second part 42 of the second element 13 and the second inner space 33’ may exhibit a complementary shape to the first part 41 of the second element 13. The first inner space 3T and the second inner space 33’ of the third element 15 may be cylindrically shaped. The second inner space 33’ may have a larger diameter than the first inner space 3T.

The second element 13 is shown in Fig. 4a-d. As can be seen, the second element 13 may comprise a first part 41 , a second part 42, a third part 43 and a fourth part 44. The parts 41-44 may be cylindrically shaped as is shown in e.g. Fig. 4a. The first part 41 and the second part 42 may be arranged to be received in the second inner space 33’ and the first inner space 3T of the third element 15 as has been described above. The parts 41-44 may exhibit a successively increasing size such that the second element 13 exhibits a straight stair shape when viewed in a cross-section as seen in Fig. 4c. The first part 41 may thus have a smaller size than the second part 42, the second part have a smaller size than the third part 43 and the third part have a smaller size than the fourth part 44. If the parts 41-44 are cylindrically shaped they will exhibit a successively increasing diameter from the first part 41 to the fourth part 44. The part having the largest size may have a size which corresponds to the size of the largest part of the first element 11 and the size of the largest part of the third element 15. In this way, the outermost surface of the nozzle 5 when assembled will be defined by the largest parts of the elements 11 , 13, 15. Furthermore, the nozzle 5 will have a substantially constant size along its extension. In Fig. 4a-4d the fourth part 44 has the largest diameter.

When connecting the second element 13 with the third element 15 the outer surface of the assembled configuration will exhibit a groove since the third part 43 of the second element 13 has a smaller diameter than the outermost surface of the third element 15 and the outermost surface of the second element 13, i.e. the fourth part 44. This groove may be arranged to receive a sealing packet 62 that will be described in greater detail below. Other ways of achieving the groove in the nozzle 5 are also contemplated, e.g. a milled groove in the outer surface of the nozzle 5 etc.

The second element 13 may be arranged to interact with first element 11 such that the second element 13 may receive parts of the first element 11. Thus, the second element 13 may comprise a receiving compartment 45, 46 which is adapted to receive a complemental end part 51 of the first element 11 which is e.g. illustrated in Fig. 5c. Thus, the end part 51 of the first element 11 may be arranged with an outer surface which at least partially exhibit a shape that complements the shape of the receiving compartment 45, 46 such that the end part 51 of the first element 11 can be inserted into the receiving compartment 45, 46 of the second element 13 in order to assemble the nozzle 5. The receiving compartment 45, 46 may comprise a first section 45 and a second section 46, the first section 45 having a cylindrical shape and the second section 46 having a frustoconical shape. The end part 51 of the first element 11 may thus exhibit a

corresponding form, e.g. by having a cylindrical part and a frustoconical part. Thus, the end part 51 fits snugly within the second section 46 so that when they are assembled a sealed connection between the end part 51 and the second section 46 is achieved.

Fig. 5a-5e illustrate the first element 11 according to embodiments herein. As has been described above, the first element 11 may be arranged to be connected to the second element 13 by being adapted to be at least partially received within the second element 13. To this end the first element 11 may comprise an end part 51 having a complementary shape to that of the receiving compartment 45, 46. The end part 51 may thus comprise a first section which is cylindrical and a second section which is

frustoconical. The length of the end part 51 may be somewhat smaller than the length of the receiving compartment 45, 46 such that when the end part 51 has been inserted into the receiving compartment 45, 46 a space is formed in the second section 46 of the second element 13 that is not occupied by the end part 51 (see Fig. 6). The length of the end part 51 may alternatively correspond to the length of the receiving compartment 45,

46 such that no space is formed in the second section 46.

Thus, by inserting a part of the first element 11 into the second element 13 and inserting a part of the second element 13 into the third element 15, the nozzle 5 may be assembled. The elements 11 , 13, 15 may be arranged with threads such that they may be screwed together during assembly. Even though the nozzle 5 has hitherto been described as comprising three sections that may be assembled into the complete nozzle 5 it is also contemplated that the nozzle 5 comprises fewer or more elements. The nozzle 5 may also be produced as one integral piece, thus only consisting of one element.

Fig. 6a-b illustrate the nozzle 5 in an assembled state. Fig. 6b show the nozzle 5 in a cross-section of Fig. 6a (section A-A). As can be seen, the nozzle 5 comprises an outlet 21 (which is also seen in Fig. 2a-b, Fig. 3a-c and Fig. 4d) arranged at the first end 22 of the nozzle 5. The outlet 21 may be arranged on the first part 41 of the second element 13 of the nozzle 5 (see Fig. 4a-4d). The first end 22 of the nozzle 5 may be composed of a part of the second element 13 (see Fig. 4a and Fig. 6) and a part of the third element 15 (see Fig. 3a-c). When the first part 41 of the second element 13 is inserted into the second inner space 33’ of the third element 15 the outlet 21 will thus discharge out of the first end 22 of the nozzle 5. The outlet 21 is adapted to inject the multi-component mixture directly into a rock hole. As has been described above, the third element 15 may have a cylindrical shape which tapers towards the first end 22 and thus also towards the outlet 21.

The multi-component mixture, also referred to herein as the mixture, is adapted for securing a bolt, e.g. a cable bolt, in the rock hole, i.e. the components in the mixture may be developed for this purpose. The multi-component mixture may e.g. consist of two components, a first and a second component. The first component may be component A containing a resin, such as for example methylene diphenyl isocyanate (MDI) or similar. The second component may be component B containing a hardener, such as for example sodium silicate, silicic acid, an alcohol, a polyol or similar, or a combination thereof.

Alternatively, the first component may be component B and the second component may be component A. The components A, B are intended to be mixed into a mixture. When the components have been mixed a chemical reaction will initiate in the resin as triggered by the hardener whereby crosslinks are created in the resin. As a consequence, the mixture hardens. This process is quite fast. It is advantageous to perform the mixing of the components A, B as close to injection of the mixture into the rock-hole as possible since this minimizes the risk that the mixture hardens within the system 1 or the nozzle 5 before it has reached the rock hole. In addition, the amount of spillage during injection is reduced.

The components A, B of the multi-component mixture are therefore intended to be provided to the nozzle 5 unmixed, i.e. separately, and to be mixed within a mixing member 23 comprised in the nozzle 5. The mixing member 23 may e.g. be comprised in an inner compartment of the second element 13. It is important that the components A, B do not come into contact with each other before they are intended to be mixed, since this may initiate the chemical reaction within the resin whereby the components A, B may harden earlier within the system 1 which may lead to blockage and subsequent malfunction of the system 1.

Therefore, the nozzle 5 comprises a first channel 31 for the first component A and a second channel 33 for the second component B. The channels 31 , 33 are best seen in Fig. 5b and Fig. 6. The channels 31 , 33 may be arranged in the first element 11 of the nozzle 5. The first element 11 is shown in detail in Fig. 5a-e. The nozzle 5 further comprises a first inlet 24 to the first channel 31 and a second inlet 25 to the second channel 33. The inlets 24, 25 are arranged on a second end 26 of nozzle 5. The second end 26 of the nozzle 5 may be opposite the first end 22 of the nozzle 5. By arranging the inlets 24, 25 of the components A, B opposite the outlet 21 , the nozzle 5 can be made elongate, without any lines 9 or elements sticking out far in the transversal direction. Thereby the nozzle 5 can be used in narrow spaces such as narrow rock holes without hitting the walls of the rock hole and risk getting stuck. This improves the manoeuvrability of the nozzle 5. The inlets 24, 25 may comprise a number of connection means 27 (see Fig. 6) for connecting a line 9 to each respective inlet 24, 25. The connection means 27 may comprise a connection plate 28 and connectors 29 as shown in Fig. 2a-c and Fig. 6. The connection plate 28 is shown from a top view in Fig. 2c and from a perspective view in Fig. 2d. As can be seen from these figures, the connection plate 28 may be arranged with recessed portions 28a arranged to receive the connectors 29, thereby allowing for a snug fit as well as a compact design. The connection means 27 are not shown in Fig. 5a-e.

The multi-component mixture is intended to be injected into the rock hole through the outlet 21. Thus, prior to being injected into the rock hole, the components A and B are mixed such that the mixture is formed. Thus, as has been described above, the nozzle 5 therefore comprises the mixing member 23 adapted to mix the first A and the second B component. The mixing member 23 may be a static mixer. The mixing member 23 may comprise a number of mixing elements. The mixing elements are arranged to cause the flow pattern of the components A, B to become turbulent in order to achieve a good mixing of the components A, B. The mixing elements may therefore consist of lattice structures or other geometrical shapes which obstructs and disturbs the laminar flow pattern of the components A, B. The mixing member 23 may be comprised in the second element 13 and be connected to the outlet 21 such that the mixture may flow from the mixing member 23 to the outlet 21. Furthermore, the first 31 and the second 33 channels may be connected to the mixing member 23 such that the components A and B may flow from the respective channel 31 , 33 to the mixing member 23. As the components A, B flow through the mixing member 23 the mixing elements cause the components A, B to be whipped into a thixotropic mix before leaving the nozzle 5 through the outlet 21. Prior to entering the mixing member 23, the components A, B may be pre-mixed by the first 31 and the second 33 channel being connected upstream of the mixing member 23, e.g. by the components A, B being discharged from their respective channel 31 , 33 into a common space. The channels 31 , 33 may be arranged in the first element 11 of the nozzle 5 wherein the channels 31 , 33 may be arranged as a Y-cross, the first element 11 may therefore be referred to as a Y-piece 11. With Y-cross is herein meant that the channels 31 , 33 converge at a certain angle into a common channel in the first element 11 or e.g. discharge into a common space 46 formed when the end part 51 of the first element 11 has been inserted into the receiving compartment 45, 46 of the second element 13 as shown in Fig. 6. The components A, B may be mixed to a degree before entering the mixing member 23. Fig. 5e shows the first element 11 as viewed in a direction towards the outlets of the channels 31 , 33, i.e. according to the embodiment when the channels 31 , 33 discharge into a common space 46. However, as has been described, there may be no common space 46, instead the channels 31 , 33 may discharge directly into the mixing member 23.

The nozzle 5 is further adapted to receive a blocking agent S. The blocking agent S may be an agent with chemical characteristics that ensures that the blocking agent S does not mix or react chemically with either of the components A, B. In addition, the blocking agent S may have protecting characteristics that protects against wear inside the nozzle 5. The blocking agent S may be a fat and viscous agent such as e.g. fat, silicone or similar. The blocking agent S may be adapted to, when pumped into the nozzle 5, extrude or push out any remaining component A, B still inside the nozzle 5. Furthermore, the blocking agent S may in addition be adapted to block any channel or line it occupies in such a way that no component A, B may enter the channel or line after the blocking agent S has been introduced into the channel or line. Thus, the blocking agent S will ensure that the channels or lines in which it is provided are clear of any remaining component A, B. The blocking agent S may be provided to the nozzle 5 via a third inlet 52 and a fourth inlet 53 as can be seen in Fig. 5c and Fig. 7. The third inlet 52 may be connected to a third channel 55 adapted to receive a blocking agent S and the fourth inlet 52 may be connected to a fourth channel 56 adapted to receive a blocking agent S. The third channel 55 may alternatively be connected to the first channel 31 and the second channel 33 such that blocking agent S may be provided to the first 31 and second 33 channel via the third channel 55. In this case there is no need for a fourth inlet 53 of the blocking agent S. Alternatively, as is shown in Fig. 5b-c the third channel 55 is connected to the first channel 31 and the fourth channel 56 is connected to the second channel 33. In this way the blocking agent S may be provided to the first channel 31 via the third channel 55 and to the second channel 33 via the fourth channel 56. Fig 5d shows the first element 11 as viewed in direction towards the inlets 24, 25, 52, 53. From Fig. 5d it can be seen that the inlets are provided symmetrically around the centre point of the cylindrical first element 11. By providing blocking agent S separately to each channel it is ensured that the blocking agent S flows through both channels and thereby cleans and blocks both channels. If the blocking agent S is provided from a common channel to both channels, there is a risk that the blocking agent S will only flow through one of the channels if the channels exhibit different pressure drops. The blocking agent S may thus be provided to the nozzle 5 through the inlets 52, 53 and extrude any component A, B still remaining in the channels 31 , 33 and/or the mixer 23.

As can be seen from Fig. 2, 6 and 7 the channels 31 , 33, 55, 56 may comprise a valve 61. Each channel 31 , 33, 55, 56 may have a dedicated valve 61. Alternatively, only one or some of the channels 31 , 33, 55, 56 comprise a valve 61. The valves 61 may e.g. be non-return valves such as check valves. By providing valves 61 in the channels it is ensured that no component A, B or blocking agent S flows in the opposite direction, i.e. towards the inlets 24, 25, 53, 54. Thereby there is no risk that the components A, B mix in the lines 9, blocking the intended flow. Furthermore, there is no risk that the blocking agent S forms a blockage where it is not intended to block the flow of fluid. The blocking agent S may be provided just after the valves 61 in the channels 31 , 33. This is advantageous since this will guarantee that there will be a distance to the position in the nozzle 5 where the components A and B meet. It is thereby guaranteed that the blocking agent S will form a barrier within the channels 31 , 33, preventing the components from meeting within the channels 31 , 33.

As is illustrated in e.g. Fig. 2a, 2b, 6 and 7 the nozzle 5 may comprise a groove for the sealing packet 62. The groove may e.g. be milled into the outer surface of the nozzle 5. Alternatively, the elements 11 , 13, 15 may be shaped such that when they are assembled into the nozzle 5, a groove is formed in the outer surface of the nozzle 5. An embodiment where this is the case has been discussed in conjunction with the discussion of the second 13 and third element 15 above. The sealing packet 62 may have a size which is a bit bigger than the groove, such that the sealing packet 62 sticks out of the outer surface of the nozzle 5 in order to prevent the component mixture or the blocking agent S from flowing over the nozzle 5 during injection of the mixture into the rock hole.

As was mentioned above in conjunction with Fig. 1 , the first component A and the second component B may be stored in respective tanks 6A, 6B or reservoirs 6A, 6B arranged on the rig 3. The tanks 6A, 6B may be arranged with breather filters in order to ensure that no air comes into contact with the components A, B in the tanks 6A, 6B. The blocking agent S may also be stored in one or several tanks or reservoirs (not shown) arranged on the rig 3.

The components A, B may be pumped from the tanks 6A, 6B to the nozzle 5 and further into the rock hole by pumps (not shown). There may be one pump arranged for each component A, B, such that the component A and B are pumped by a respective dedicated pump. The pumps pumping the components A, B may e.g. be hydraulically powered gear pumps. Flow meters (not shown) may be arranged before or after each pump in order to measure the flow of the components A, B. The measurements may be used to ensure that the right flow and mix ratio is achieved between the components A, B. Furthermore, filling pumps for filling the tanks 6A, 6B with component A, B may be arranged on the rig 3. These filling pumps may be arranged with filters.

Similarly, the blocking agent S may be pumped from the tank containing the blocking agent S to the nozzle 5 by pumps. The pump or pumps may e.g. be piston pumps. In the case where two lines 9 are used for the blocking agent a twin pump, having two channels or lines connected to the two lines 9 may be used. The piston pumps may be refilled with blocking agent S using an air pump, e.g. an air powered grease drum pump. The air pump may also push the piston pump back to its starting position.

The pumps and sensor data may be monitored by a rig control system. The pumping may thereby be synchronized with the injection of components A, B and blocking agent S as well as the movement of the nozzle 5 performed by the feeding device 7.

As was described above a number of lines 9 may be connected between the storage of the components A, B and the blocking agent S and the nozzle 5. Thus, some of the lines 9 may run from the tanks 6A, 6B to the nozzle 5 and some of the lines 9 may run from the tank or tanks storing the blocking agent S and the nozzle 5. With lines 9 is herein meant a number of tubes, hoses or similar that provide a fluid communication between the storage of the components A, B as well as the blocking agent S and the nozzle 5. Thereby the components A, B and the blocking agent S may flow from the storage to the nozzle 5 in order to be injected into the rock hole. The blocking agent S may be pumped through more than one line 9, e.g. two lines 9, in order to block each channel 31 , 33 where components A, B flow in the nozzle 5. Alternatively, one line 9 may be used for the blocking agent S, which line 9 connects to both channels 31 , 33 as has been described above. According to a preferred embodiment four lines 9 are used; a first line for the first component A, a second line for the second component B, and a third and a fourth line for the blocking agent S. For clarity reasons the invention will be explained below in accordance with this embodiment, but with the understanding that fewer or more than four lines 9 may be used.

The system 1 may further comprise a winding member 10 capable of supporting the lines 9 in a winding manner, i.e. such that the lines are wound around a centre point of the winding member 10. The winding member 10 according to some embodiments herein is shown in greater detail in Fig. 8a. The winding member 10 may e.g. be a hose reel. The winding member 10 stores the extra length of the lines 9 when the entire length of the line 9 is not used. When the nozzle 5 is moved into the hole by the feeding device 7 the feeding device 7 is pulling the lines 9 from the winding member 10. When the nozzle 5 is retracted from the hole, the winding member 10 may be turned by a motor (not shown) which winds the lines 9 on the winding member. The motor may e.g. be a hydraulic motor. The winding member 10 may have a swivel 81 arranged in the centre. The swivel may have connecting means for each of the lines 9, e.g. one connection means for each line 9 leading the components A, B and one connection means for each line 9 leading the blocking agent S. Lines 9 may then lead from the swivel 81 to the sources of the components and/or the blocking agent. Thereby there is no risk of the lines tangling in the winding member 10 during operation.

The lines 9 may be arranged within an outer package 12 holding the lines 9 together as shown in Fig 8a, Fig. 8b, Fig. 8c and Fig. 9b. This outer package 12 may comprise a tubular section 95 made out of a material that is flexible but preserves enough rigidity to be able to hold the weight of the nozzle 5 without bending. The material may e.g. be rubber, plastic, PEX tube, shrink tube etc. Fig. 8c illustrates how three lines 9 may be arranged within the outer package 12. Fig. 9b illustrates how four lines 9 may be arranged within the outer package 12. The outer package 12 may be referred to as a transfer hose 12 and serves the purpose of supplying the components A, B and the blocking agent S to the nozzle 5. The outer package 12 further serves the purpose of simplifying the manoeuvring of the nozzle 5 up and down in the rock hole, since it facilitates the gripping and feeding of the lines 9 and the nozzle 5. Furthermore, the outer package 12 improves the stability of the nozzle 5 by being able to support the weight of the nozzle 5 as explained above, making it easier for the feed device 7 to make the nozzle 5 enter the rock hole. In addition, the outer package 12 protects the lines 9 from damage during operation. The outer package 12 may comprise a number of first connectors 82 arranged to connect the lines 9 in the outer package 12 to the nozzle 5. The outer package 12 may further comprise a number of second connectors (not shown) arranged to connect the lines 9 in outer package 12 to the swivel 81 in the winding member 10. The outer package 12 may alternatively be connected directly to the nozzle 5 and the swivel 81. When the lines 9 are arranged in an outer package 12, the outer package 12 is wound on the winding member 10. The outer package 12 may comprise a two-piece tube arranged to encapsulate the connection complex arranged between the nozzle 5 and the lines 9, which connection complex comprises the connectors 29, the first connectors 82 and a portion of the lines 9. The two-piece tube comprises two tube halves 92 that are joined together by at least one clamping member 93. The two-piece tube provides extra protection to the connection complex during operation. The outer package 12 may further comprise a coupling member 94 arranged to connect the tubular section 95 to the nozzle 5 directly or indirectly.

The feeding device 7 according to an embodiment herein is illustrated in greater detail in Fig. 9a. The feeding device 7 is adapted to move the nozzle 5 by interacting with at least one line 9 connected to the nozzle 5. In Fig. 9a the feeding device 7 interacts with the outer package 12 in order to move the nozzle 5 relative to the system 1 and/or the rig 3. Thus, the feeding device 7 may interact indirectly with the lines 9 through the outer package 12. The feeding device 7 may comprise a number of feed rollers 91 adapted to move the nozzle 5 relative to the system 1. The feeding device 7 may e.g. comprise two or four feed rollers 91. According to the embodiment shown in Fig. 9a four feed rollers 91 are used. Thereby a stable feeding device 7 is achieved which may move the nozzle 9 in a precise and robust manner. A sensor may be arranged to monitor the position of the nozzle 5 as well as the feeding speed. The sensor may e.g. be a sensor wheel. The feeding device 7 may also be arranged to inject a cable bolt into the rock hole after the hole has been filled with the component mixture. For this purpose, the feeding device 7 may comprise separate feed rollers for the cable in order to feed the cable into the hole. A sensor may be used in the same manner as for the nozzle 5. Furthermore, a cable bending mechanism, a cable cutter as well as a push cylinder adapted to push the cable into the hole after being cut may be arranged on the feeding device 7 for this purpose.

The system 1 may furthermore comprise a means for performing a post insertion treatment on the bolt. The post insertion treatment may perform one or more out of:

vibrating the bolt, pulsating the bolt or rotating the bolt.

The post insertion means may thus e.g. comprise vibration means. The vibration means may be arranged on the system 1. The vibration means causes the bolt to vibrate after it has been inserted into the rock hole. By causing the bolt to vibrate is herein meant that the bolt is caused to move continuously back and forth in the axial direction of the bolt over a distance of 1-10 mm, preferably 1-5 mm, most preferably 1-2 mm. The vibration means may e.g. be arranged in conjunction with the feeding device 7. The vibration means may e.g. be the feed rollers 91 whereby the feed rollers 91 cause the bolt to vibrate after having inserted the bolt into the rock hole. Alternatively, the vibration means is a dedicated vibration means solely designed to cause the vibration of the bolt.

The post insertion means may alternatively or additionally comprise pulsating means. The pulsating means may be arranged on the system 1 , e.g. in conjunction with the feeding device 7. The pulsating means causes the bolt to pulse after it has been inserted into the rock hole. By causing the bolt to pulse is herein meant that he bolt is caused to move continuously back and forth in the axial direction of the bolt over a distance of 50-200 mm, preferably 50-150 mm, most preferably 80-120 mm. A typical pulsating value may e.g. be 100 mm. Similarly to the vibrating case the feed rollers 91 may be used to cause the bolt to pulse. Alternatively, a dedicated pulsating means may be used.

The post insertion means may alternatively or additionally comprise a rotating means which may be arranged on the system 1 , e.g. in conjunction with the feeding device 7. The rotating means causes the bolt to rotate. The rotation may exhibit an axis of rotation which is parallel to the longitudinal axis of the bolt. The rotating means may comprise a gripping means capable of gripping the bolt. After having gripped the bolt the entire rotating means may rotate in such a manner that the bolt is rotated. Alternatively, only the gripping means of the rotating means is rotated in order to cause the bolt to rotate within the rock hole.

By rotating, vibrating and/or pulsating the bolt after it has been inserted into the rock hole a better adherence of the mixture to the bolt may be achieved since the mixture may reach all small holes and bends on the cable and thereby stick to the entire surface area of the bolt. This improves the attachment of the bolt to the rock and thereby the rock reinforcement.

A method for injecting a multi-component mixture into a rock hole, wherein the mixture is adapted for securing a bolt in the rock hole, will now be described in

conjunction with Fig. 10. The method steps that are optional are marked with dashed lines in the figures. The bolt may e.g. be a cable bolt.

The method steps that are described below may e.g. be performed by a control unit in a known manner. The method may e.g. be performed by the system 1 described above. The system 1 may then be arranged on a rig 3 and comprise the control unit. The control unit may comprise at least one processor, at least one memory and at least one data port. The at least one processor is usually an electronic processing circuitry that processes input data and provide appropriate output.

Fig. 10 illustrates an exemplifying method for injecting a multi-component mixture into a rock hole, wherein the mixture is adapted for securing a bolt in the rock hole. The method comprises: to place 1001 a nozzle 5 into the bottom of a rock hole, where the nozzle 5 is adapted for injecting the multi-component mixture into the rock hole. The mixture is adapted for securing a bolt in the rock hole. The nozzle 5 comprises the first channel 31 adapted to receive a first component A of the multi-component mixture and the second channel 33 adapted to receive the second component B of the multi- component mixture. The nozzle 5 further comprises a third channel 55 adapted to receive a blocking agent S. The third channel 55 is connected to the first channel 31 such that the blocking agent S can be provided to the first channel 31 via the third channel 55. The nozzle 5 further comprises a mixing member 23 adapted to mix the first A and the second B component prior to injecting the mixture of the first A and the second B component into the rock hole. The nozzle 5 further comprises an outlet 21 at a first end 22 of the nozzle 5 adapted to inject the mixture of the first A and the second B component directly into the rock hole.

The method further comprises: to inject 1002 the multi-component mixture into the rock hole by providing the first A and the second B component of the multi-component mixture into the first 31 and the second 33 channel of the nozzle 5 respectively.

The method further comprises: to provide 1003 the blocking agent S into the first 31 and second 33 channel of the nozzle 5. The blocking agent S may be provided into the first 31 and/or second 33 channel of the nozzle 5 via the third channel 55. Alternatively, the nozzle 5 may comprise a fourth channel 56 adapted to receive the blocking agent S, wherein the third channel 55 is connected to the first channel 31 such that the blocking agent S can be provided to the first channel 31 via the third channel 55, and wherein the fourth channel 56 is connected to the second channel 33 such that the blocking agent S can be provided to the second channel 33 via the fourth channel 56. The blocking agent S is then provided into the first channel 31 via the third channel 55, and into the second channel 33 via the fourth channel 56. The method further comprises: to, while injecting the multi-component mixture into the rock hole, continuously move 1004 the nozzle 5 out of the rock hole by retracting the nozzle 5 from the bottom of the hole towards the entry of the hole.

The step of continuously moving 1004 the nozzle 5 out of the rock hole may preferably be performed before the step of providing 1003 the blocking agent S into the first 31 and second 33 channel of the nozzle 5.

By following the above described method, the rock hole is filled with a multi- component mixture which will secure a bolt that is placed in the rock hole. Furthermore, the nozzle 5 is readied by extracting any lingering component A, B such that it may fill another rock hole with the mixture.

The method for securing a bolt in a rock hole may further comprise: to insert 1005 a bolt into the rock hole. Thereby the bolt will be secured in the rock hole when the mixture hardens. The rock will thus be reinforced by the bolt. The bolt may e.g. be a cable bolt.

According to some embodiments the step of inserting 1005 the bolt into the rock hole is performed after the nozzle 5 has been completely removed from the rock hole. Thereby the nozzle 5 will not be hinder the bolt from accessing the rock hole.

According to some embodiments the step of providing 1003 the blocking agent S is performed just before the nozzle 5 has been completely removed from the rock hole.

In the method described above, the rock hole is considered to have been already drilled. This may also be part of the method. Thus, as a preliminary step the rock hole may be drilled 1000 by a drilling machine arranged on the rig 3.

The method may further comprise: to, after the step of inserting 1005 the bolt into the rock hole, perform 1006 a post insertion treatment of the bolt inside the rock hole.

The post insertion treatment 1006 may comprise one or more of rotating, vibrating or pulsating the bolt.

By vibrating the bolt is herein meant that the bolt is moved continuously back and forth in the axial direction of the bolt over a distance of 1-10 mm, preferably 1-5 mm, most preferably 1-2 mm. By pulsating the bolt is herein meant that the bolt is moved continuously back and forth in the axial direction of the bolt over a distance of 50-200 mm, preferably 50-150 mm, most preferably 80-120 mm. A typical distance may e.g. be 100 mm.

By rotating the bolt is herein meant that the bolt is rotated around an axis of rotation. The axis of rotation may e.g. coincide with the longitudinal axis of the bolt.

By rotating, vibrating and/or pulsating the bolt after it has been inserted into the rock hole a better adherence of the mixture to the bolt may be achieved since the mixture may reach all small holes and bends on the cable and thereby stick to the entire surface area of the bolt. This improves the attachment of the bolt to the rock and thereby the rock reinforcement.

According to some embodiments herein there is provided a computer program which comprises program code for causing a control unit or a computer connected to the control unit to carry out the method as was described above.

According to some embodiments herein there is provided a computer-readable storage medium storing a computer program, wherein said computer program comprises program code for causing a control unit or a computer connected to the control unit to carry out the method as was described above.

The computer program may comprise routines for controlling operation of the system 1 as was described above. The computer program may comprise routines for controlling insertion and post insertion treatment of a bolt.

Even though the invention has been described in conjunction with a number of examples above, the description is only meant to illustrate inventive concepts and does not limit the scope of the invention. Terms such as“blocking agent”,“line” and“multi- component mixture” have for example been used throughout the description, but corresponding entities, function and/or parameters could also have been used that comprise the features and/or characteristics that has been described in conjunction to the terms herein. The invention is defined by the attached patent claims.