WO2001011193A1

WO2001011193A1 - Arrangement for fixing rock bolts during rock reinforcement

Info

Publication number: WO2001011193A1
Application number: PCT/SE2000/001541
Authority: WO
Inventors: Jan Marklund
Original assignee: Jama Mining Equipment Ab
Priority date: 1999-08-05
Filing date: 2000-08-04
Publication date: 2001-02-15
Also published as: AU6486400A; SE514495C2; SE9902843D0; SE9902843L

Abstract

The invention concerns an arrangement for fixing rock bolts during rock reinforcement that includes: a drilling machine (5) that is forwards and backwards displaceable along an axis of rotation (10); an adapter (42) attached to the chuck of the drilling machine, the free end of which is designed for the removable fixation and rotatable driving of one end of a drilling rod (8) with a drilling cutter (9) that is appropriate for rock drilling, or of one end of a rock bolt (21) for introduction into a drilled hole; holder devices (20; 34, 35) for removable retention of the drilling rod or rock bolt in a storage position; and devices (20; 34, 35) for transfer of the drilling rod or rock bolt from the storage position to a position for connection to the adapter that is coaxial with the axis of rotation of the drilling machine; together with devices (20; 34, 35) for removal of the drilling rod from the said connection position to the storage position. In order to make possible the use of only one machine for both drilling and insertion of bolts, the drilling machine (5) is reversible and the free end of the adapter (42) and the end of the drilling rod (8) for attachment to the adapter include sections that are designed to enter into and be removed from rotational engagement with each other by mutual rotation whereby the grip devices (36) are arranged to be brought into and out of engagement with the drilling rod, that the free end of the adapter (42) and the end of the rock bolt (21) for connection to the adapter include sections (46; 21') that can be axially connected to each other whereby one of the sections is rotationally incorporated into the other.

Description

Arrangement for fixing rock bolts during rock reinforcement

The present invention concerns an arrangement for fixing rock bolts during rock reinforcement according to the preamble to claim 1.

The invention particularly concerns an arrangement for fixing roof-anchoring bolts or what are known as "rock bolts" in tunnels and other underground constructions in mine locations.

Specially developed devices known as "rigs" are used during rock reinforcement by the fixing of rock bolts. The rigs are equipped with equipment for drilling holes in the rock, injecting cartridges that contain a hardenable resin into the drilled hole and finally fixing a rock bolt into the hole. The rock bolt is set into the hole by the execution of a slow rotary motion and it is provided at its front end with a drilling tip, the purpose of which is to perforate the cartridges so that the hardenable resin is brought into contact with the atmosphere and hardens. The rock bolt that is anchored in the hole is pressed against the rock surface by the tightening of a nut, with its associated plate, arranged on a threaded part of the free end of the rock bolt.

The use of a special adapter for transfer of the rotary motion of the drilling machine and blows to the drilling rod and its associated drilling cutter is known. The known adapter is designed for the connection of a drilling rod and displays at its free end a centrally placed bottom hole for connection to the end of the drilling rod and a radial hole that communicates with the axial bottom hole. The opening of the radial hole is surrounded by a water box by means of which fluid can be led to flow via the said opening into the radial hole and further through the axial hole before being finally led through the drilling rod and out through the drilling cutter in order to rinse away debris and dust that has been produced during the drilling operation. Once the hole has been drilled and the cartridge containing resin has been injected into the drilled hole, the drilling machine is taken away and replaced by a machine for fixing the rock bolts in the drilled hole that is placed in line with the drilled hole. Thus it should be realised that the operation requires two sets of machines, a drilling machine with its associated drilling rod for drilling the hole and a drilling machine for fixing the rock bolt itself.

One disadvantage of known arrangements for this purpose is thus that they require two separate machines. Furthermore, arrangements for swapping between the said machines are required.

The intention of the present invention is to achieve an arrangement of the type described above that makes it possible to use only one machine for both drilling and for fixing the bolt.

The intention is achieved by the arrangement according to the present invention demonstrating the characteristics that are specified in the claims. The invention will be described in more detail in the following with reference to the attached drawings, of which fig. 1 shows a view in perspective of the arrangement for fixing rock bolts according to the invention, fig. 2 shows the parts that are included in the arrangement according to the invention in an exploded view, fig. 3 shows a side view, in partial longitudinal section, of a drilling machine that is part of the arrangement when in the drilling position, fig. 4 shows a side view, in partial cross section, of the drilling machine seen in fig. 2 when in the position for fixing a rock bolt into a drilled hole, fig. 5 and fig. 6 show a schematic cross-section through a part of a provision that is included in the arrangement for removal of a drilling rod from the drilling machine, fig. 7 and fig. 8 show a schematic cross-section through part of a magazine for rock bolts that is included in the arrangement together with a provision for transfer of rock bolts from the magazine to the position for fixing into a drilled hole, fig. 9 and fig. 10 show a schematic cross-section through a part of a support for the drilling rod that is included in the arrangement in an inactive position and in an active position, and fig. 11 and fig. 12 show a schematic cross- section through a part of a provision that is included in the arrangement for injecting plastic cartridges that contain resin into a drilled hole.

The arrangement shown in fig. 1 includes a feed beam 1 that is supported on a feed beam holder 2. The feed beam holder 2 is supported in a known manner on a bar that in turn is supported by a carrier, not shown in the figure. The feed beam holder 2 is arranged to pivot around the said bar via a joint, not shown in the figure. The feed beam 1 is displaceably guided in the longitudinal direction by means of the guides 3, and can be adjusted relative to the feed beam holder 2 by the influence of suitably arranged piston- and cylinder devices. The feed beam 1 is equipped at its front end with a tip 4 for pressing against a rock surface.

A reversible drilling machine 5 is carried by a sledge 6 which can be guided as it slides along the feed beam 1. A driving mechanism for the sledge 6 is arranged in the form of a chain transmission, taken up into the feed beam, that is driven by a driving device 7, with the aid of which the drilling machine 5 can perform forward and backward, working and return motions along the feed beam 1. During the said motions, a drilling rod 8 that is fixed into the drilling machine 5 moves, together with its associated drilling cutter 9, along an axis 10 that is coaxial with the axis of rotation of the drilling machine and that lies parallel to the principal axis of the feed beam 1. The drive device 7 is designed in a known manner in such a way that the sledge 6 can be driven with a variable speed of feeding, and is equipped with pulse sensors or other known technology that makes it possible to determine the position of the sledge 6, and thus also the position of the drilling machine 5, on the feed beam 1 at any instant. Signals from the said sensor are fed to a control unit, and it is appropriate that the control unit includes a computer.

The arrangement is equipped with supports for the drilling rod 8, of which a first, forward, drill support 11 is arranged at the front end of the feed beam 1 and a second, rear, drill support 12 is arranged in the region of the approximate centre of the length of the feed beam 1. The drill supports 11, 12 are positioned on opposite sides of the feed beam 1 and each includes, as is shown in figs. 7-10, an arm 13 that is jointed to pivot with the feed beam 1 and arranged to pivot into and out from the feed beam 1 by means of a piston- and cylinder device, not shown in the figure, that operates between the feed beam and the arm 13. The arm 13 is equipped at its free end with a claw-like control 14 for the drilling rod 8. As is most clearly seen in figs. 7-10, the claw-like control 14 includes a holder defined by two halves of circles that can be moved relative to each other, one half 15 being stationary while the other half 16 is designed as a link that is jointed to pivot with the arm 13 and arranged to pivot between an open and a closed position with the aid of a piston- and cylinder device 16'. When the control 14 is in the closed position, it follows that a ring-shaped holder for the drilling rod 8 is formed, while the drilling supports 11, 12 are allowed to pivot out from the drilling rod when the control is in its open position.

As is most clearly shown in figs. 11 and 12, one end of an arm 17 is pivotally fixed at the front end of the feed beam 1, opposite to the front drill support 11, and arranged to pivot into and out from the feed beam 1 by means of a piston- and cylinder device 18 that is active between the feed beam and the arm. At its free end, the arm 17 supports a mouthpiece 19 that forms part of a device for the injection of plastic cartridges containing resin into a drilled hole. When the arm is pivoted in against the feed beam 1, the mouthpiece 19 can be brought into a position in which it coincides with the central axis 10 of the drill. As is shown in fig. 1 , a holder in the form of a drum-like magazine for rock bolts, generally denoted by the figure 20, is attached to the feed beam. The rock bolts 21 are of the type that is provided at one end with plates 22 for pressing against the rock surface. The magazine for rock bolts 21 is constructed around a shaft 23 that is supported in rotating bearings by a first arm 24 and a second arm 25, each of which is jointed to pivot with the feed beam 1 and arranged for simultaneous pivoting into and out from the feed beam 1 by means of a piston- and cylinder device 26, 27. The shaft 23 is provided at each end with a set of flange-like parts 28, 29, 30 that protrude radially from the shaft, around the perimeter of which the rock bolts are equally distributed. The functions of the said flange-like parts are to hold the rock bolts separate at a distance from each other both in the radial and in the axial direction, and to allow a detachable mounting of the rock bolts, which in the embodiment that is described here is achieved by means of sprung finger-like grip devices 31, 32 produced from wire-like material and arranged at mutually equal distances around the circumference of two of the said flange-like parts 28, 29. The shaft 23 provides rotational driving of the magazine 20, by means of a transmission that is connected in a manner that transfers power from a drive unit in the form of a motor 33. The said drive unit is designed in such a way that the magazine 20 can be positioned into specified angular positions. Transfer of rock bolts 21 from the magazine 20 to a position that is coaxial with a previously drilled hole occurs by the magazine 20 being turned or indexed forward to a specified angular position, after which the magazine is pivoted in towards the feed beam 1 such that the rock bolt 21 that is to be fixed into the hole is positioned coaxial with the axis of rotation 10 of the drilling machine 5.

A first holder 34 and a second holder 35 for the drilling rod are arranged on the side of the feed beam that is situated opposite to the magazine 20, each of which includes grip devices 36 that can be engaged with and disengaged from a drilling rod 8 that is fixed into the drilling machine 5, and that can also remove the gripped drilling rod from its working position in the drilling machine. As is most clearly seen in figs. 5 and 6, each of the said holders contains an arm 37 that is jointed to pivot with the feed beam 1 and arranged to pivot into and out from the feed beam 1 by means of a piston- and cylinder device 38. The grip device 36 is arranged at the free end of the arm 37 and contains a stationary part 39 in the form of an opening in the form of a semicircle positioned at one end of the arm, together with a mobile part 40 in the form of an opening similarly shaped in the form of a semicircle attached by a pivot to the arm which, by means of a piston- and cylinder device 41, is arranged to pivot between an open position and a closed position in collaboration with the stationary part 39. In order to ensure that the drilling rod is securely fixed in the grip devices it is appropriate that at least one of the grip devices 36 is provided with internal teeth that act against the circumference of the gripped drilling rods.

An adapter 42 that is part of the present invention is shown in fig. 2. The adapter demonstrates a first end 43 that is designed for attachment to the chuck of the drilling machine 5 and a second free end to which it is intended that one end of the drilling rod 8 or one end of the rock bolt 21 is to be removably attached, for rotating driving. The free end 43 of the adapter is provided with an external thread that is designed to collaborate with an equivalent internal thread 45 arranged at the end of the drilling rod 8. An axial recess, generally denoted by 46, is arranged at the centre of the free end of the adapter, and demonstrates a non-circular section 47 at its outer part and a circular section 48 at its inner part, and in which sections it is intended that one end, denoted by 21 ', of the rock bolt 21 is to be screwed in.

Since the free end of the adapter 42 and the end of the drilling rod 8 that is intended for connection to it both normally demonstrate external threads, an intermediate piece 49 has been arranged for the connection between the free end of the adapter 42 and the drilling rod 8, which intermediate piece is arranged with internal threads in the bottom hole. The holes in the intermediate piece 49 are connected with each other via a channel 50 such that rinse water can be led through the intermediate piece 49 and onwards through the drilling rod 8. It is appropriate if the free end of the adapter 42 and the end of the intermediate piece

49 for attachment to the same are provided with pipe threads of type R55, and that the connection to the drilling rod is provided with pipe threads of type R32.

The non-circular recess 46 in the centre of the operative end of the adapter 42 demonstrates a shape that is hexagonal when seen in cross-section and, in other words, has a shape that is equivalent to the shape of nut 51 that is arranged at the end of the rock bolt 21. The axial circular bore 48 that is positioned further into the depression 46 has a diameter that is selected such that the threaded axial section of the rock bolt 21 can be inserted into the same. Somewhat further into the recess 46, the axial bore 48 becomes a bore with a reduced diameter that communicates with a channel that runs radially and that opens out into the perimeter of the adapter (not shown in the figure). The opening can, by means of a water box that surrounds the adapter 42, or similar, be connected in a known manner with a source that supplies rinse water which, via the said opening and radial holes, is led onwards through the axial hole in the adapter 42 via the hole 50 in the separate intermediate piece 49 before being finally led through the drilling rod 8 and further out through the drilling cutter in order to rinse away debris and dust that is produced during the drilling operation.

As is shown in figs. 3 and 4, the sledge is equipped with a device 52 the function of which is to lock the nut 51 of the rock bolt 21 in place when it is located in the recess 46 of the adapter 42. The locking device in principle includes a fork 53 that can be moved via a manoeuvring link 54 and a piston- and cylinder device 55 between a first, non-operational position in which the fork 53 is positioned at a distance such that the end of the drilling rod 8 can be connected to the free end of the adapter 42, as is shown in fig. 3, and a second, operational position in which the nut 51 of the rock bolt 21 is fixed to the adapter 42, as is shown in fig. 4. The function and method of operation of the arrangement described above are most clearly explained by figs. 5-12. When the sledge 6, and thus also the drilling machine 5, is located at the rear end position along the feed beam 1, the first holder 34 and the second holder 35 of the drilling rod 8 are pivoted inwards, as is shown by the arrow 44 in fig. 5, such that the drilling rod that is positioned in the grip devices 36 of the holders is positioned with an orientation that is coaxial with the axis of rotation 10 of the drill, and is thus positioned for connection to the free end of the adapter 42 of the drilling machine 5. The sledge 6 is fed forwards during slow anti-clockwise rotation of the adapter 42 positioned in the chuck of the drilling machine 5, until the drilling rod 8 has been screwed fast onto the end of the adapter. The rear support 12 for the drilling rod is pivoted inwards from its outward rest position and the claw-like control 14 is closed around the drilling rod 8 in order to control the same. The grip devices 36 of the first holder 34 and the second holder 35 for the drilling rod 8 are opened and the said holders return to their rest positions, as is shown in fig. 6.

The drilling machine 5 is rotated and fed forwards along the feed beam 1 by means of the sledge 6 with parameters with respect to rate of revolution and speed of feed that are determined for the drilling operation. When the drilling cutter 9 has passed the forward drilling support 11 , which in this case is positioned in an outward rest position, this support is also pivoted in and the drilling rod 8 is enclosed by the claw-like control 14 of the same. During the forward motion of the sledge 6 along the feed beam 1 the supports 11 and 12 are pivoted outwards at appropriate times in order to prevent collision with the drilling machine 5. When the sledge 6, and thus also the drilling machine 5, has reached its end position on the feed beam 1, a hammer arrangement that is part of the drilling machine is activated in order to free initially the drilling rod 8 from the adapter 42. The sledge 6 is fed backwards along the feed beam 1 towards the rear initial position, whereby the drill supports 11 , 12 are pivoted inwards during the motion of the sledge as the drilling machine passes the said drill support. When the sledge 6 is located in the rear initial position, the first holder 34 and the second holder 35 for the drilling rod are pivoted in and their respective grip devices 36 are activated in order to grip the drilling rod 8, whereby the drilling machine is slowly rotated clockwise until the drilling rod 8 has been unscrewed from the adapter 42. In association with the exchange of tools in the drilling machine described above, the arm 17 is pivoted in, as is shown in figs. 11-12, such that the mouthpiece 19 that is part of the injection device is positioned coaxial with the drilled hole. By means of the injection device, which is connected by the tube 56 to a source of pressure medium for injection of cartridges containing resin, the said cartridges are fed into the hole, after which the arm 17 that carries the mouthpiece 19 is pivoted outwards to its resting position.

The bolt magazine 20 is indexed as is shown in figs. 7 and 8 such that a rock bolt 21 is presented in a position for delivery, after which the magazine is pivoted in such that the said rock bolt is placed coaxial with the drilled hole and thus is also positioned in line with the axis of rotation 10 of the drilling machine, and hence for connection to the free end of the adapter 42 of the drilling machine 5. The sledge 6 is fed forwards during slow anticlockwise rotation of the adapter 42 that is fixed into the chuck of the drilling machine 5, until the nut of the rock bolt has been inserted into the recess of the adapter, after which the locking device 52 for the nut 51 is placed into its operational position such that the nut is securely located in the adapter. The forward support 11 and the rear support 12 are pivoted in from their outward rest positions and the claw-like control 14 is caused to enclose the rock bolt 21 for control of the same, after which the rock bolt magazine 20 is pivoted out to its rest position. The drilling machine 5 is rotated anticlockwise and fed forwards along the feed beam by means of the sledge 6 towards the rock surface for fixing of the rock bolt 21 into the drilled hole. During the forward motion of the sledge 6 along the feed beam 1, the supports 11, 12 are pivoted outwards at appropriate times in order to prevent collision with the drilling machine 5. The locking device 52 for the nut is positioned into its inactive position just before the rock bolt 21 reaches its end position. When the rock bolt 21 reaches its end position, the drilling machine 5 stops until the resin has hardened in the hole, after which the drilling machine is reactivated and rotated clockwise for placement of the nut 51 and plate 22 against the rock surface. The sledge 6 is once again fed backwards along the feed beam 1 towards its initial position, and a new work-cycle can begin.

The present invention is not limited to that which is described above and shown in the drawings, but can be changed and modified in a number of different ways within the framework of the innovative concept specified in the following claims.

Claims

1. Arrangement for fixing rock bolts during rock reinforcement that includes a drilling machine (5) that is forwards and backwards displaceable along an axis of rotation (10), an adapter (42) attached to the chuck of the drilling machine, the free end of which is designed for the removable fixation and rotatable driving of one end of a drilling rod (8) with a drilling cutter (9) that is appropriate for rock drilling, or of one end of a rock bolt (21) for introduction into a drilled hole whereby the rock bolt is of the type that for pressing against the rock surface demonstrates at one end a body (51) that can be axially positioned on a thread with a non-circular outer cross-section designed for influence by turning, holder devices (20; 34, 35) for removable retention of the drilling rod or rock bolt in a storage position and devices (20; 34, 35) for transfer of the drilling rod or rock bolt from the storage position to a position for connection to the adapter that is coaxial with the axis of rotation of the drilling machine, together with devices (20; 34, 35) for removal of the drilling rod from the said connection position to the storage position, c h a r a c t e r i s e d in that the drilling machine (5) is reversible and that the free end of the adapter (42) and the end of the drilling rod (8) for attachment to the adapter include sections that are designed to enter into and be removed from rotational engagement with each other by mutual rotation whereby grip devices (36) are arranged to be brought into and out of engagement with the drilling rod, that the free end of the adapter (42) and the end of the rock bolt (21) for connection to the adapter include sections (46; 21 ') that can be axially connected to each other whereby one of the sections is rotationally incorporated into the other.

2. Arrangement according to claim 1 , wherein the free end of the adapter (42) includes an external thread (44) designed to collaborate with an equivalent internal thread (45) arranged at the end of the drilling rod (8) and in that an axially running recess (46) is arranged at the centre of the free end of the adapter into which it is intended that the adjustable body (51) of the rock bolt is to be rotationally inserted.

3. Arrangement according to claim 1 or 2, wherein the grip devices (36) form part of the holder devices (34, 35) for the drilling rod (8).

4. Arrangement according to any of claims 1-3, wherein the holder devices (34, 35; 20) for the drilling rod (8) and the rock bolt (21) are located on opposite sides of the axis of rotation (10) of the drilling machine (5).

5. Arrangement according to any of claims 1-4, wherein it includes controls (14) for the drilling rod (8) that is attached to the drilling machine, which controls can be opened and moved between a closed position in which they form a holder that surrounds the drilling rod, and an open position in which the control can be removed from the said drilling rod.