EP0034134A1

EP0034134A1 - Rock bolting apparatus

Info

Publication number: EP0034134A1
Application number: EP81850017A
Authority: EP
Inventors: Nils Axel Ägren
Original assignee: Atlas Copco AB
Current assignee: Atlas Copco AB
Priority date: 1980-02-08
Filing date: 1981-02-03
Publication date: 1981-08-19
Also published as: SE420856C; NO810356L; SE8001018L; AU6697481A; FI810312L; SE420856B; EP0034134B1; DE3163791D1; ATE7728T1; JPS56139396A; ZA8127B

Abstract

A rock bolting apparatus includes a rock drill (40) and a bolt setting machine (50) which are carried by a swingable unit connected to a boom (11), the swingable unit (18) being swingable relative to the boom (11) about a given axis (21). The rock drill (40) and the bolt setting machine (50) are laterally displaceable into and out of working position by means of a controlled swinging movement of the swingable unit (18) about the given axis (21). In order to fix the given axis (21) in relation to the rock surface (45) during the swinging movement, the swingable unit (18) is clampable between the rock surface (45) and the boom (11) by a jack (63) arranged on the swingable unit, the jack (63) being extensible in alignment with the given axis (21). The swingable unit (18) further includes a first feed (26) bar for feeding and guiding the rock drill (40) and a second feed bar (27) for the bolt setting machine (50), the feed bars (26, 27) being mutually displaceable by power in their longitudinal direction.

Description

This invention relates to a rock bolting apparatus including a rock drill and a bolt setting machine, and more particularly to an apparatus wherein drilling, bolting and, if desired, resin insertion, can be accurately and quickly carried out in succession.
Such a rock bolting apparatus is previously known from German Patent Specification No 22 22 646. This known apparatus has a feed bar which is common to the rock drill and the bolt setting machine, the rock drill and the bolt setting machine being situated on two opposite sides of the common feed bar. The drill rod and the rock bolt are guided by respective supports located at the end of the feed bar which is directed towards the rock surface. To achieve an effective guidance, at least the drill rod support should abut against the rock surface. However, rock bolting often takes place in tunnels with a rough surface or else the bolting could be needed obliquely to the surface. When using this prior art apparatus under such circumstances, the bolt support will often hit projecting rock parts before the drill support has gotten sufficient abutment against the rock surface. Correspondingly, the drill support often hits projecting or other rock parts when the swingable unit is turned to the position for inserting resin cartridges or bolts. As a result of these disadvantages, the drill hole will not always be as required because of adjoining rock irregularities or because the bolt will not be inserted sufficiently deep in the drill hole.
It is an object of this invention to provide a rock bolting apparatus avoiding the disadvantages of the kind mentioned above and which apparatus will make it possible to insert rock bolts by machine power even if the rock surface is uneven or inclined.
In accordance with the invention, a rock bolting apparatus includes at least a rock drill and a bolt setting machine both of which are carried by a swingable unit connected to a boom, the swingable unit being swingable relative to the boom about an axis; power means for power displacing the rock drill and the bolt setting machine laterally into and out of a working position by means of controlled swinging of the swingable unit about said axis; and clamping means for clamping the swingable unit between a rock surface and the boom, the clamping means including a jack arranged on the swingable unit and being extensible in alignment with said axis. The improvement of the invention resides in that the swingable unit comprises a first feed bar movably mounted thereon and carrying the rock drill for feeding and guiding the rock drill; a second feed bar (27) movably mounted thereon and carrying the bolt setting machine; and power displacing means coupled to the feed bars for power displacing the two feed bars independently of each other relative to the swingable unit in the longitudinal direction of the feed bars.
In a preferred arrangement, the first and second feed bars are mounted relative to said axis such that on swinging movement of the swingable unit about said axis, both said rock drill and said bolt setting machine are in alignment with the hole being drilled.
In the drawings:

Fig 1 is a side view of a rock bolting apparatus according to the invention;
Fig 2 is a view seen as indicated by the arrows 2-2 in Fig 1;
Fig 3'is a view seen from above as indicated by the arrows 3-3 in Fig 1 but on an enlarged scale; .
Fig 4 is a cross-section along the line 4-4 in Fig 3 but on a somewhat reduced scale; and
Fig 5 is a fragmentary cross-section along the line 5-5 in Fig 3 but on an enlarged scale.

In Fig 1 there is shown a boom 11 mounted to a suitable transportable chassis 12 by a universal joint 13. The boom 11 is laterally swingable by means of a hydraulic cylinder 14 arranged between the chassis 12 and the joint 13 while vertical movement of the boom 11 is achieved by a pair of cylinders 15 arranged between the joint 13 and the arm 11. A vertically swingable supporting means 16 is attached to the free end of the boom 11. The-swinging motion of supporting means 16 is achieved by a hydraulic cylinder 17 arranged between the boom 11 and the supporting means 16. A swingable unit 18 is in turn attached to the supporting means 16 by two bearings 19 and 20 and is laterally swingable relative to the arm 11 about an axis 21 by means of a pair of cylinders 22 arranged between the supporting means 16 and the swingable unit 18.
The two cylinders 22 are arranged in some suitable way in order to give their piston rods 23 three distinct mechanical stop positions whereby the swingable unit 18 is given three defined working positions. In Figs 1-3 the unit 18 is shown in its second working position in which the piston rods 23 are projected to half their length against a middle stop position.
As seen in Figs 2 and 4, the swingable unit 18 has a central box-shaped supporting frame 24 with brackets 25 arranged thereon, the brackets 25 holding a first 26 and a second 27 feed bar on two opposite sides of the frame 24. The feed bars 26 and 27 are displaceable relative to the frame 24 by the operation of hydraulic cylinders 28 and 29 (Figs 4), each of which is connected to a respective feed bar 26 and 27. The cylinders 28 and 29 are arranged side by side in a plane through the axis 21 as seen in Fig 3. In Fig 4 the cylinders are, for clarity, shown side by side in a plane perpendicular to said first plane. They may take other positions. The cylinders 28 and 29 are located in the frame 24 having their piston rods 30 and 31 protruding from the upper part of said frame 24 and being attached to respective brackets 32 and 33 on the respective feed bar 26, 27. The feed bars 26 and 27 are displaceable by means of cylinders 28 and 29 in a direction parallel to the axis 21. During such motion the feed bars 26, 27 are guided by tracks 34 mounted on two opposite sides of the feed bars and being adapted to run in corresponding notches in the brackets 25.
The feed bars 26 and 27 may each be constructed as the feed bar disclosed in German Patent Specification No 28 20 325, but also other feed bars can be suitable.
As seen in Figs 1-4, an impact rock drill 40 is arranged on a cradle which is feedable in a conventional way along the first bar 26. A drill rod 42 connected to the rock drill 40 goes through a hole in a drill support 43 arranged at the upper end of the feed bar 26. The support 43 includes a cushion 44 of an elastic material which is adapted to abut against the rock. surface 45 and having a hole 46 therein whose diameter is adapted to the drill bit to enable the drill bit to be at least partly drawn into the cusion 44 and to be guided by the same when collaring a hew hole. The support 43 includes further an elastic sleeve 47 whose hole is equal to the diameter of the drill rod 42 and is dapted for guiding said drill rod 42. A bowl- shaped part 48 is located between the cusion 44 and the sleeve 47 and is arranged for collecting the flushing water mixed with cuttings flowing out of the drill hole 49.
A machine 50 for setting bolts 51 is arranged on the second feed bar 27. The machine 50 comprises a nut running tool with fluid-pressure drive mounted on a cradle 52 movable along the feed bar 27. The head of the bolt 51 is receivable in a rotatable socket 53 also carrying a washer 54 threaded on the bolt 51. A support 55 for the bolt 51 is arranged at the upper part of the feed bar 27 and includes an arm 56 which is turnable aside. The arm 56 has a gripping means 57 adapted for gripping and guiding the bolt 51. When.the washer abuts the arm 56, the arm 56 and gripping means 57 are swung upwardly about pivot 61 (Fig 3) so that the gripping of the bolt 51 is released and the washer may pass upwardly past the arm 56 and gripping means 57.
A charging tube 58 for resin cartridges is carried by the supporting frame 24 and is axially displaceable by an hydraulic motor 59. The lower end 60 of the tube 58 is connectable to a hose (not shown) in which the resin cartridges are inserted and pneumatically transported to the drill hole 49.
The unit 18 further includes an upwardly protruding frame part 62 having an hydraulic jack 63 disposed therein. Jack 63 whose upper part is shown in Fig 5 comprises an hydraulic cylinder 64 mounted to the upper end surface of the frame part 62. A piston rod 65 is extensible from the cylinder 64,said rod 65 having a bearing sleeve 66 screwed on the free end thereof. The bearing sleeve 66 carries a clamping head 67 journalled on the sleeve by a radial bearing race 68 and an axial bearing race 69. As a result of the bearing shape, rotation of the clamping head 67 is allowed without any declination in relation to the piston rod. The clamping head 67 is adapted to abut against the rock surface when the apparatus is used and has therefore a cushion 70 of elastic material for providing a favorable grip against the rock. The rotation axis of the clamping head 67 is arranged to coincide with the longitudinal axis 71 of the hydraulic cylinder 64, said axis 71 in turn coinciding with the axis 2L The drill rod 42, the charging tube 58 and the bolts 51 are so disposed that they are in parallel to the axis 21 and are located the same distance from axis 21. At the swinging movement of the swingable unit 18, these devices 42, 58, 51 will therefore describe a motion along one and the same arc 72 as indicated by the chain- dotted line in Fig 3.
The operation of the rock bolting apparatus will now be further described. First the apparatus is set in the drilling position by displacing the piston rods 23, Fig 3, to their full length so they will reach their external stop position. The unit 18.is thus turned 45° to the first working position in which the drill rod 42 will coincide with the charging tube 58 position shown in Fig 3. Then the first feed bar 26 is positioned so that the drill rod 42 will point at the desired drilling position for the bolt. Then, the bar 26 is displaced towards the rock surface 45, causing the drill support 43 to abut thereagainst as seen in Fig 4. Then the hydraulic cylinder 64, Fig 5, is activated to press the clamping head 67 towards the rock to thus clamp the unit 18 between the rock and the arm or boom 11. To increase the clamping force, the feed bar 26 is further pressed against the rock by the hydraulic cylinder 28, Fig 4, enabling the clamping head 67 to be fed in succession thereto and to thereby protrude still another bit to increase the clamping effect. Thereafter the feed bar 26 is somewhat withdrawn while the hydraulic cylinder 64 is kept in its extended position by means of a suitable hydraulic lock (not shown). By the described cooperation between the hydraulic cylinders 28 and 64 the effective clamping force will be greater than if only the hydraulic cylinder 64 of the clamping head 67 should have been used, thus enabling the indexing to be accurately done about one carefully fixed axis 21. During the setting of the unit 18 against the rock, both the feed bar 27 for the bolts 51 and the charging tube 58 are displaced backwards so that they will not knock against irregularities in the rock surface.
When the unit is satisfactorily clamped against the rock the drilling is started. During the collaring the drill bit is guided by the hole 46 in the cushion 44 while the drill rod throughout the complete drilling operation is guided by the sleeve 47. When the required hole depth has been reached the drilling machine 40 with the drill rod 42 is fed backwards and the feed bar 26 is displaced from the rock by the hydraulic cylinder 28. Then the piston rods 23 are drawn back into cylinders 22 to their middle stop position making the unit 18 turn 45⁰ about the axis 21 while the clamping head 67 is maintained in immovable abutment against the rock. The unit 18 will now be in the second working position which is that position shown in Fig 3 with the charging tube 58 located in alignment with the drill hole 49. The charging tube 58 is fed up into the hole by the hydraulic motor 59 and resin cartridges are inserted in a suitable way. When the charging operation has been completed the charging tube 58 is drawn back from the hole and the unit 18 is turned another 45° to the third working position in which the bolt 51 will be aligned with the drill hole 49. The third position will be defined by drawing back the piston rods 23 into cylinders 22 to their inner stop position. The feed bar 27 for the bolt setting machine 50 is now positioned a suitable distance from the rock surface so the bolt 51 can be inserted to a sufficient depth by means of the-bolt setting machine 50. During insertion, the bolt 51 is guided by the gripping means 57 until the bolt has gone so far into the hole as the washer 54 must pass the arm 56. The gripping means 57 will at that time release the guiding grip about the bolt and is folded upwards, thus enabling the washer 54 and the.machine 50 to be brought to abutment against the rock surface. The bolt 51 is then in a known way fixed to the rock by harde- ening of the resin and tightening of the bolt. The bolting operation is now completed and the clamping head 67 is drawn back so that the unit 18 is set free and is able to be.positioned for another bolting operation.
By virtue of the fact that the bolting apparatus comprising two feed bars 26 and 27 which are displaceable independently of each other, the apparatus can be positioned so that the one feed bar which is brought to a working position will be situated sufficiently close to the rock surface to enable satisfactory guidance and feed length to the drill rod and bolts without being hindered by the other feed bar hitting irregularities in the rock.

Claims

1. In a rock bolting apparatus including at least a rock drill (40) and a bolt setting machine (50) which are carried by a swingable unit (18) connected to a boom (11), the unit (18) being swingable relative to the boom (11) about an axis (21); power means for power discplacing said rock drill (40) and said bolt setting machine (50) laterally into and out of a working position by means of controlled swinging of the swingable unit (18) about said axis (21); and clamping means for clamping said swingable unit (18) between a rock surface and the boom (11), said clamping means including a jack (63) arranged on said swingable unit (18) and being extensible in alignment with said axis (21); characterized in that said swingable unit (18) comprises: a first feed bar (26) movably mounted thereon and carrying said rock drill (40) for feeding and guiding said rock drill (40); a second feed bar (27) movably mounted thereon and carrying said bolt setting machine (50); and power displacing means (28-33) coupled to said feed bars (26, 27) for power displacing said two feed bars (26, 27) independently of each other relative to said swingable unit (18) in the longitudinal direction of said feed bars.

2. Rock bolting apparatus according to claim 1, characterized in that said swingable unit (18) comprises a common supporting frame (24) for said feed bars (26, 27), said common supporting frame (24) comprising guiding means for each one of said feed bars (26, 27) to permit displacement of said feed bars in their longitudinal direction relative to said frame (24).

3. Rock bolting apparatus according to claim 2, characterized in that said common supporting frame (24) carries said power displacing means.

4. Rock bolting apparatus according to claim 3, characterized in: that said common supporting frame (24) is box-shaped; said power displacing means comprises hydraulic cylinders (28, 29) arranged inside said common supporting frame (24); and said guiding means comprises brackets (25) at opposite sides of said common supporting frame (24) for slidingly holding said feed bars (26, 27).

5. Rock bolting apparatus according to any one of claims 1-4, characterized in that said first feed bar (26) has a support (43) at one end thereof, said support (43) being adapted to abut against a rock surface when said first feed bar (26) is pressed towards the rock surface.

6. Rock bolting apparatus according to claim 5, characterized in that said support (43) has a hole therethrough for guiding a drill rod connected to the rock drill (40), and that said support (43) has an elastic cushion (44) on the part thereof adapted to contact the rock surface.

7. Rock bolting apparatus according to claim 5 or 6, characterized in that the power displacing means (28) for said first feed bar is arranged to cooperate with said jack (63) during the clamping of said swingable unit (18) so that their cooperative compressiveforce will determine the clamping force.

8. Rock bolting apparatus according to any of the previous claims, characterized by a clamping head (67) coupled to said jack (63), said clamping head (67) being arranged to abut against the rock surface and being rotatable with respect to said jack (63).

9. Rock bolting apparatus according to claim 8, characterized in that said clamping head (67) includes an elastic cushion (70) on the part thereof adapted to contact the rock surface.

10. Rock bolting apparatus according to claim 8 or 9, characterized in that said clamping head (67) is connected to the jack (63) by a connection (66) which permits rotary movement only in a plane perpendicular to the jacking direction of said jack.