ARRANGEMENT FOR FEEDING BONDING MATERIAL

Abstract: The invention relates to an arrangement for feeding bonding material into a space between a bolt and rock. The arrangement comprises a sleeve-like nozzle (3), which can be pushed tightly against a feed chamber (2d) which belongs to the rock bolt so that the feed hole (2f) in the feed chamber is connected to the inner space of the nozzle (3). The arrangement further comprises means for feeding bonding material inside and through the nozzle to the feed chamber. The arrangement also comprises means for placing the nozzle around the feed chamber.

Description: ARRANGEMENT FOR FEEDING BONDING MATERIAL The invention relates to an arrangement for feeding soldering material into a space between a bolt and rock using a rockbolt for bolting, which comprises a separate guide tube around the actual bolt, the guide tube being connected to a feed chamber, which is provided with a feed hole for feeding soldering material into the feed chamber and further into a drill hole through the guide tube, the bolt being arranged to travel through the feed chamber so that it can be fixed in the hole before feeding the soldering material. To support rock in tunnel construction and mining, it is nowadays rather common to use a rockbult in which the end to be pushed into the hole is provided with locking members, such as a wedge anchor, which is then tightened with a support flange and a nut included in the bolt. To fix the bolt firmly to the rock and to protect it from corrosion, the space between the bolt and the hole wall has to be filled with soldering material, such as concrete. In practice, it has been difficult to implement soldering, which has led to development of a new bolt structure, which is described in US patent no. 5,636,945. In this solution, a tube to be arranged around the bolt is fastened to a support flange, which will rest against the rock surface, and connected to the feed chamber attached to the flange. There is a hole on the side of the feed chamber, and soldering material can be fed into the feed chamber through this hole and a nozzle for soldering material pushed into the hole and further inside the above- mentioned tube through the feed chamber. From the tube, the soldering material flows along an annular channel between the tube and the bolt to the end of the bolt and back to the beginning of the tube along an annular channel be- tween the tube and the hole walls. Thus the free space can be filled with soldering material reliably and efficiently, and it can be noted that the space is filled up as concrete starts to penetrate out of the hole. According to the above- mentioned patent, the flange is provided with a hole through which the soldering material that has got between the flange and the rock can penetrate, and thus it can be noted that the hole is filled up. In this bolt structure it is, however, difficult to fill the space with soldering material. To feed soldering material into the feed chamber reliably, the nozzle for soldering material has to be pushed manually into a hole on the side of the feed chamber. This is laborious, difficult and slows down the bolting considerably. Furthermore, in most cases the worker has to be in a cage or the like to reach to bolt, even though the bolt could be fed and the nut tightened mechanically with a bolting device. The above-mentioned manual stages also pose a considerable safety risk because the worker has to work under a rock that has not been reinforced. An object of the present invention is to provide an arrangement which enables filling of a drill hole with soldering material safely, easily and, thanks to mechanization, economically using a rockbolt provided with a guide tube and a feed chamber. The arrangement according to the invention is characterized in that it comprises a sleeve-like nozzle which can be placed tightly around the feed chamber so that the feed hole of the feed chamber is con- nected to the inner space of the nozzle, and that the arrangement comprises means for feeding soldering material inside the nozzle and therethrough into the feed chamber, and means for placing the nozzle around the feed chamber. The invention is based on the idea of using, instead of a nozzle for soldering material which is difficult to push tightly into a hole provided on the side of the feed chamber, a sleeve-like nozzle which in the operating position surrounds the feed chamber and in which the inner circumference of the sleeve tightens against the outer surface of the feed chamber and/or the front edge of the sleeve tightens against the flange so that soldering material, when fed into the sleeve, cannot penetrate from between the sleeve and the flange or from between the sleeve and the outer surface of the feed chamber. Instead, the material penetrates into the guide tube through the hole on the side of the feed chamber and further inside the upper part of the bolt, and back down from between the guide tube and the drill hole, which was the intention in the design of the bolt. Another basic idea is that the sleeve-like nozzle is con- nected to mechanical means which can place it on top of the feed chamber so that soldering material can be fed safely by feeding means of soldering material attached to the nozzle, the feeding means being guided by actuators provided in the usual place on the base of the drilling device. Thus the user does not need to move from his position to feed soldering material. The invention will be described in greater detail in the accompanying drawings, in which Figure 1 schematically illustrates a bolt provided in a drill hole and feeding of soldering material with a nozzle member belonging to the arrangement according to the invention, Figures 2a to 2c illustrate tightening of the nozzle member to the feed chamber of the bolt and to the flange in greater detail, Figures 3a and 3b schematically illustrate a bolting device by means of which soldering material can be fed using the arrangement of the invention, and Figures 4a and 4b schematically illustrate another embodiment of the arrangement according to the invention. Figure 1 schematically illustrates a bolt 2 pushed into a drill hole 1 , the upper end of the bolt being provided with locking members 2a. The locking members 2a may be implemented using any suitable means of locking, such as wedge locking. There is a guide tube 2c around the part 2b of the bolt that actually carries the load. The lower end of the tube is connected to a feed chamber 2d. There is also a flange 2e attached to the feed chamber so that the guide tube 2c, feed chamber 2d and flange 2e form an entity. The feed chamber 2d is round in cross-section and comprises a feed hole 2f through which soldering material can be fed into the feed chamber 2d and further in- side the guide tube 2c. The actual bolt part 2b travels through the feed chamber 2d and a nut 2g or another clamping member for tightening the bolt using wedge locking to provide adequate tightness before feeding soldering material. The figure also shows a sleeve-like nozzle 3 for soldering material which is placed around the feed chamber 2d after the bolt 2 has been tight- ened. The nozzle 3 comprises a sealing surface 3a which settles tightly along the outer surface of the feed chamber 2d, thus forming a tight joint with the feed chamber 2d. The sealing surface may be formed on the sleeve-like inner surface of the nozzle to provide a slightly conical sleeve-like inner surface as shown in the figure. In that case, as the nozzle is pushed, the conical sealing surface 3a is pressed against the outer surface of the feed chamber 2d, which is round in cross-section, thus forming a line-like contacting surface which functions as a seal. There is also a delivery hose 4 connected to the nozzle 3. Soldering material can be fed into the nozzle through the hose and from the nozzle into the feed chamber and further. The nozzle 3 is connected to a sup- porting arm 5 shown in the figure or to another supporting member by means of which it can be pushed into its place for feeding of the soldering material. A device suitable for this purpose is shown in greater detail in Figures 4a and 4b. Figures 2a to 2c illustrate embodiments for tightening the nozzle 3 against the feed chamber 2d or the flange 2e, which differ from those shown in Figure 1. Figure 2a illustrates an embodiment where a seal 3b for sealing the nozzle 3 against the feed chamber 2d is provided on the inner surface of the nozzle 3. The inner surface of the seal 3b is preferably slightly conical, in which case it will seal easily against the feed chamber 2d. The inner surface of the seal may also have a different shape, i.e. the inner surface can be completely cylindrical or partly cylindrical with a conical front edge. Seals of other kind can also be used. Figure 2b illustrates a solution in which a seal 3c is provided at the front edge of the nozzle 3, the seal being pressed against the flange 2e as the nozzle 3 is placed in its operating position around the feed chamber 2d. Figure 2c shows a solution in which the nozzle 3 is provided with a sleeve-like seal 3d, which forms a uniform seal from inside the nozzle 3 to its front edge, preferably beyond the front surface as shown in the figure. Such a sleeve-like seal is easy to produce and install, and it can be changed quickly when it is worn out. Figures 3a and 3b are schematic side and top views of a rock bolting apparatus in which the arrangement can be applied. A rock bolting device 6, which is fully known per se and described e.g. in German patent no. 2222646, is attached to a boom 7 whose one end is attached to a base (not shown), which is fully known per se. The rock bolting device 6 is pivoted to the boom 7 in a manner known per se, for which reason this is not described in greater detail. The rock bolting device 6 comprises e.g. a drilling machine for drilling a hole in the rock first. The drilling machine moves along a feed beam 8 as shown in the figure. It further comprises a bolt feeding device 11 , which moves along another feed beam 10. The apparatus may also include a bolt cartridge and transfer members known per se (not shown) for transferring bolts to the feeding device 11. Such bolt cartridges and transfer members are fully known per se, and since they are not relevant to the present invention, they will not be described in greater detail. The rock bolting device further comprises a vertical joint 12, which is parallel with the axis of the feed beams 8 and 10 and around which the rock bolting device can be turned so that the rock drilling machine 9 and the bolt feeding device 11 will be in the same place to allow remote-controlled, or if desired, totally automatic feeding of a bolt into a drilled hole. This is called indexing, which is fully known per se e.g. from German patent no. 2222646, and thus its function and actuators need not be described in greater detail. In addition, the figure shows a feeding unit 13 for soldering material, which is provided with a sleeve-like nozzle of Figures 1 or 2a to 2c included in the arrangement according to the invention. This sleeve-like nozzle is arranged with respect to the axis 12 so that it can be turned coaxially with the drilled hole. The nozzle 3 can preferably be moved with respect to the bolting device 6 parallel with the axis 12, and it comprises an actuator 14, preferably a pressure-fluid operated cylinder, by means of which the nozzle 3 can be firmly placed around the feed chamber of the bolt and held there to feed preferably concrete into the drill hole around the bolt through the feed chamber. Figures 4a and 4b schematically illustrate other embodiments of the nozzles included in the arrangement according to the invention. In these embodiments the nozzle 3' is also sleeve-like and is arranged in the bolt feeding device 11. The bolt feeding device 11 , which moves along the feed beam 10 shown in Figures 3a and 3b when a bolt is being fed, comprises a rotating tool 11 a, which contains a clamping space 11 b for a clamping member, such as the nut 2g of the bolt or the like, which rotates the nut 2g of the bolt shown in the figure during pre-fastening of the bolt. In this embodiment the tool 11 a is ar- ranged to pass through the bottom of the nozzle 3' and sealed against the nozzle with a seal 11 c so that soldering material cannot penetrate out from between the nozzle 3' and the tool 11 a. In this embodiment the bolt can be pushed into its place when the nozzle 3' is around the feed chamber 2d of the bolt. After the bolt has been pushed into the hole, it can be pre-tightened to its place by the tool 11a, after which soldering material can be immediately fed into the drill hole through the feed chamber 2d. It is also possible to start feeding of soldering material already during tightening of the nut. Figure 4b illustrates another embodiment of the arrangement of the invention where the tool 11a of the bolt feeding device 11 is provided with one or more openings 11d, such as holes, which extend from the clamping space 11 b of the tool 11 a to the outer surface of the tool 11 a. In that case any soldering material that has penetrated into the clamping space 11 b can exit it when the next bolt is introduced, and thus the clamping space 11 b cannot fill with soldering material, which might interrupt the bolting. Naturally, the tool 11 a can be implemented in several ways, provided that it can rotate the nut of the bolt and any other component of any shape used for tightening. It is essential that the tool and the component used for tightening are compatible so that the bolt can be pre- tightened to its place. A bolt the upper end of which is provided with threads or a similar component which is rotated to provide pre-tightening can also be ap- plied in the arrangement of the invention. The above description and drawings only exemplify the invention and do not limit the invention in any way. It is essential that the arrangement comprise a sleeve-like nozzle which can be arranged around the feed chamber of the bolt so that it seals against the feed chamber and/or the flange, which enables feeding of soldering material into the drill hole through the feed chamber in the intended manner. Thus soldering can be performed even though the bolt were not provided with a tube around it in accordance with US patent no. 5,636,945, but with a feed chamber in connection with the flange.

Claims: CLAIMS 1. An arrangement for feeding soldering material into a space between a bolt and rock using a rockbolt for bolting, which comprises a separate guide tube (2c) around the actual bolt (2), the tube being connected to a feed chamber (2d), which is provided with a feed hole (2f) for feeding soldering material into the feed chamber and further into the drill hole through the guide tube, the bolt being arranged to travel through the feed chamber so that it can be fixed in the hole before feeding the soldering material, characterized in that the arrangement comprises a sleeve-like nozzle (3), which can be placed tightly around the feed chamber (2d) so that the feed hole (2f) of the feed chamber (2d) is connected to the inner space of the nozzle (3), and that the arrangement comprises means for feeding soldering material inside the nozzle (3) and therethrough into the feed chamber (2d), and means for placing the nozzle (3) around the feed chamber (2d). 2. An arrangement according to claim 1, characterized in that the inner surface of the nozzle (3) is provided with a sealing surface (3a), which is arranged to be pressed against the outer surface of the feed chamber (2d). 3. An arrangement according to claim 2, characterized in that the sealing surface (3a) of the nozzle (3) consists of a separate seal (3b) inside the nozzle (3). 4. An arrangement according to any one of claims 1 to 3, c h a r - acterized in that the front edge of the nozzle (3) is provided with a seal (3c), which is arranged to be pressed in a bolt provided with a flange (2e) against the surface of the flange (2e). 5. An arrangement according to any one of claims 1 to 4, c h a r - acterized in that the sleeve (3) comprises a separate sleeve-like seal (3d), which extends from its inner surface up to its front edge, thus forming a sealing surface both on the inner surface of the sleeve and at its front edge. 6. An arrangement according to any one of the preceding claims, characterized in that the nozzle (3) is arranged in a bolt feeding device (11) in a rock bolting device (6) known per se, that the bolt feeding device comprises a clamping tool (11a) which is arranged to rotate the clamping member of the bolt (2), such as a nut (2g) or the like, and that the clamping tool (11a) is arranged to travel through the nozzle (3) in its axial direction so that the bolt (2) can be pushed into a drill hole with the bolt feeding device and tightened to its place and soldering material can be fed into the feed chamber (2g) through the nozzle (3) and further into the drill hole substantially in one stage. 7. An arrangement according to claim 6, c h a r a c t e r i z e d in that the tool (11a) of the bolt feeding device (11 ) comprises a clamping space in which the clamping member of the bolt (2) can settle, and that there is at least one opening (11d) from the clamping space (11 b) to the side of the tool (11a) so that soldering material that has penetrated into the clamping space can exit it as the clamping member of a new bolt is introduced into the clamping space. 8. An arrangement according to any one of claims 1 to 6, c h a r - a c t e r i z e d in that the nozzle (3) is arranged in a rock bolting device known per se and that it comprises at least one actuator for transferring the bolt in the longitudinal direction of the nozzle around the feed chamber (2d) and for removing it from around the chamber.

Inventors: KATAJA AULIS, PELTONEN VESA, ULVELIN KIMMO, KATAJA, AULIS, PELTONEN, VESA, ULVELIN, KIMMO
Applicants: KATAJA AULIS, PELTONEN VESA, SANDVIK TAMROCK OY, ULVELIN KIMMO, KATAJA, AULIS, PELTONEN, VESA, ULVELIN, KIMMO
Application year: 2000
Main classification: E21D20
IPC codes: E21D20, E21D21