Turret for roof bolting apparatus

This turret has a head 6 enabling, after the drilling of a hole 15, the injection of a resin cartridge without modifying the position of the turret 1. A movable member 8, displaced by a jack 14, has a first passage 11 traversed by the drilling rod 4, and a second passage 12 connected to the hose 13 for the injection of resin cartridges. After the drilling of the hole 15 and the retraction of the drilling apparatus 2, the movable member 8 is displaced such that the drilling rod 4 is laterally retracted by bending. The second passage 12 is simultaneously brought in line with the axis of the hole 15 so as to enable the injection of one or more resin cartridges.

BACKGROUND OF THE INVENTION 
The present invention relates to a forward turret of a drilling apparatus 
or so-called "roof bolter", particularly for use in drilling a hole in the 
roof of a mine, and enabling the injection of resin cartridges or the like 
in the hole to secure one end of a bolt in the hole and enabling the other 
end to support the roof of a mine gallery. 
Former support techniques include the use of expansion bolts having 
expandable anchor members at one end thereof. With the bolt inserted in 
the hole, the bolt is rotated to secure the bolt in the base of the hole 
by means of expansion, and after which further tightening of this bolt 
causes the compression of the ground in the form of a column coaxial to 
the said bolt. To carry out the drilling of the hole, the positioning of 
the bolt and the tightening of the bolt, it is known to use an apparatus 
comprising a pivoting turret supporting a drilling carriage and a bolting 
carriage. The first of these carriages is a drilling machine which enables 
the initial drilling of the hole, after which the turret is rotated about 
its pivot axis such that the second carriage is brought into the axis of 
the previously drilled hole for the insertion and tightening of the bolt. 
Apparatus of this type is disclosed in particular in U.S. Pat. No. 
3,246,705. 
Developments in support techniques led to the replacement of the expansion 
bolts by resin-sealed bolts. The resin used takes the form of elongate 
cartridges. These may be inserted manually into the previously drilled 
hole, before the positioning of the bolt. However, the manual insertion of 
the cartridges requires time and skilled operators. In addition, it is 
difficult to carry out if the roof of the mine is particularly high. It 
has therefore been attempted to reduce the manual work required for this 
operation by adding a resin cartridge injection device to the drilling and 
bolting turrets. After the hole has been drilled, the turret is pivoted 
into an intermediate position in which the cartridge injection device is 
located in the axis of the bolt. One or more cartridges are then inserted 
into the hole by mechanical or pneumatic means. Finally, a further 
pivoting of the turret brings the bolting carriage into the axis of the 
hole into which the resin cartridges have been inserted. A 
"three-position" turret of this type is disclosed, for example in the 
Published German Pat. No. 2 222 646. However, with the turret of 
"three-position" type, there is always a risk, despite the fact that the 
turret is anchored in the roof along its pivoting axis, that after the 
first rotation of the turret the cartridge injection device may not be 
brought exactly into the axis of the hole drilled in the initial position 
of the turret. In order to avoid this problem, it has already been 
envisaged to provide a turret in which the drilling of the hole and the 
injection of the cartridges are carried out successively without moving 
the turret. For this purpose, the forward head of the turret is provided 
with a first passage for the drilling rod and a second passage for the 
admission of the resin cartridges, this second passage intersecting and 
opening into the first passage at an angle of approximately 30.degree. see 
U.S. Pat. No. 4,398,850. After drilling of a hole, the drilling rod is 
therefore retracted and, without displacing the turret which remains 
anchored to the rock, the resin cartridge(s) are injected into the hole 
via the second passage and then the first passage of the turret head. A 
single rotation of the turret is then sufficient to bring it into a second 
position enabling bolting. This enables the structure of the turret to be 
simplified as compared to the "three-position" turret. 
However, in the case of the two-passage turret head each cartridge of resin 
must pass, during its travel, through a bend which is fairly pronounced 
and which corresponds to the connection between the two passages provided 
in the forward head of the turret. This leads to various drawbacks 
including the following: 
Deflection of the cartridge with respect to the theoretical axis of 
injection during passage through the bend, this phenomenon being amplified 
by wear of the outer end of the first passage in the forward head with the 
result that the deflected cartridge tends to catch on the inlet of the 
drilled hole. 
Friction of the cartridge against the walls of the forward head passages, 
this friction required the use of reinforced cartridges and causing a loss 
of kinetic energy preventing full penetration of the cartridge into the 
drilled hole (i.e., to the base of the hole). This drawback is 
particularly great when several cartridges are to be injected into the 
same hole. 
As the cartridge injection passage communicates with the drilling rod 
passage, the flexible injection hose which delivered the resin cartridge 
to the cartridge injection passage is not sheltered from rock debris and 
water resulting from the drilling operation. It is then necessary to blow 
compressed air through this hose during and/or after drilling, which leads 
to a loss of time and causes the operator and the apparatus to be sprayed 
with water and debris. 
The forward turret head having its two passages connected in the form of an 
elbow joint, is of comparatively large size, in particular in the 
longitudinal direction of the turret which limits the travel of the 
drilling machine. 
The forward turret head must be completely replaced if it is desired to 
drill holes and inject cartridges having different diameters. 
SUMMARY OF THE INVENTION 
The present invention obviates the above-noted drawbacks of the two-passage 
turret head. For this purpose, this invention essentially relates to a 
forward turret of a drilling apparatus, enabling the injection of resin 
cartridges or the like after drilling of a hole without modification of 
the position of the turret occupied during the drilling operation. This 
forward turret has a head comprising a guide member which is mounted to be 
movable in a direction which is substantially transverse to the direction 
of the drilling rod, the movable guide member comprising a first passage 
adapted to receive the drilling rod and a second passage, which is 
completely separate from the first, and is connected to the end of the 
resin cartridge injection hose. Means are further provided for the 
displacement of the movable guide member between a drilling position, in 
which its first passage is located on the axis of an aperture in the end 
of the head, and an injection position, in which its second passage is 
brought into the axis of the aperture. In the injection position, the 
drilling rod engaged in the first passage of the movable guide member is 
then laterally retracted by bending. 
When the movable guide member of the head is in its first or drilling 
position, the drilling rod may be pushed through the first passage of this 
movable guide member and the aperture in the head for the drilling of the 
hole. After retraction of the drilling apparatus, the drilling rod is 
retracted to the side by the displacement of the movable guide member 
which is actuated by a jack or like control means. The second passage to 
which the end of the injection hose is connected, is simultaneously 
positioned facing the aperture in the body of the head and therefore faces 
the previously drilled hole. The injection of the cartridge then takes 
place in alignment with the drilled hole with no bend in the path of the 
cartridge and therefore no risk of deflection with respect to the hole and 
with very little friction which limits the kinetic energy of the cartridge 
and improves its depth of penetration in the hole. Consequently, the wear 
of the drilling rod passages also has little effect on the successful 
injection of the cartridge. 
In addition, by means of this invention, the cartridge injection hose is 
distanced from the axis of the hole in the drilling position of the 
movable portion of the head, and is therefore sheltered from the rock 
debris and water produced by the drilling. This avoids the need to clean 
the hose with compressed air during and/or after the drilling, and 
therefore reduces time losses and prevents the operator and the apparatus 
from being sprayed with water and debris. 
In accordance with a particular embodiment of this forward turret of a 
drilling apparatus, the movable guide comprises a first member which 
includes the passage designed to be traversed by the drilling rod and 
which is mounted slidably on the body of the head in a direction 
perpendicular to the direction of the drilling rod, and a second member 
which comprises the passage connected to the end of the injection hose. 
The second member is mounted on the body of the head so as to pivot about 
an axis perpendicular to the direction of movement of the drilling rod, 
with mechanical connection means being provided between the sliding member 
and the pivoting member. In one embodiment, there is provided a jack 
articulated on one end on the body of the forward head and, on the other 
end on the pivoting member, for the purposes of displacing this pivoting 
member directly between the two positions. In addition, a connection rod 
is articulated, on one hand, on the sliding member and, on the other hand, 
on the pivoting member so as to transmit the movement of the latter to the 
sliding member. 
This construction enables the head to be made of a length which is less 
than that of a two-passage turret head whilst improving the guide length 
of the drilling rod which is important with respect to the straightness of 
the hole, the wear of the forward head and the service life of the 
drilling rods, and which enables the travel of the drilling apparatus to 
be increased. A free space may be provided between the sliding member 
traversed by the drilling rod and the pivoting member connected to the 
resin cartridge injection hose, so that during passage from the drilling 
to the injection position, rock debris and water which may have been 
trapped by the forward head are automatically ejected towards the base of 
the turret or slideway, which enables the cartridge to be injected without 
the need for preliminary cleaning using compressed air. 
Finally, the configuration of the forward turret drilling head of the 
invention provides for the drilling of holes and the injection of 
cartridges of different diameters, simply by the replacement of the 
wearing parts whilst retaining the body of the forward head. 
Other objects and features will be in part apparent and in part pointed out 
hereinafter.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIGS. 1 to 4 show, in diagrammatic form, a drilling turret 1 supporting a 
drilling apparatus 2 which is displaced along a longitudinal axis 3 and a 
drilling rod 4 having a bit 5 at its end. The forward head of the turret, 
shown generally at 6, which is the subject matter of the present invention 
is at the end of the turret 1. 
The forward head 6 of the turret comprises a fixed upper body member 7 and 
a lower guide member 8 which is movable with respect to the body 7 in a 
direction substantially transverse to the axis 3. The body 7 of the 
forward head 6 is provided with pointed projections or tongs 9 so that it 
can be anchored to the mine roof, and comprises a guide aperture 10 
provided along the axis 3. 
The movable member 8, located below the body 7, has two separate passages 
11 and 12. The first passage 11 has the form of a simple aperture, whereas 
the second passage 12 is connected to the end of a flexible hose 13 
designed for the injection of resin cartridges. A double-acting jack 14 is 
attached to the movable member 8 to move it between the two operating 
positions. 
As the forward head 6 is anchored to the mine roof by the tongs 9, the 
movable member 8 is initially positioned in the drilling position, in 
which the axis of its first passage 11 is positioned along the axis 3--see 
FIG. 1. The drilling apparatus 2 is then actuated so as to push the 
drilling rod 4 through the first passage 11 of the movable portion 8 and 
the aperture 10 of the body 7 of the head 6 so as to carry out the 
drilling of the hole 15--see FIG. 2. 
After drilling of the hole 15, the drilling apparatus 2 is retracted until 
the drilling rod 4 is released from the body 7. When the bit 5 of the rod 
4 reaches the level of the first passage 11 of the movable member 8, the 
drilling apparatus 2 is stopped. The jack 14 is then actuated so as to 
displace the movable portion 8 towards the injection position, in which 
the drilling rod 4 is retracted to the side by bending, as shown in FIG. 
3. 
Simultaneously, the displacement of the movable member 8 brings the second 
passage 12 of the latter into the axis 3, as an extension of the aperture 
10 of the body 7. The end of flexible hose 13 is then located opposite the 
previously drilled hole 15, and this hose 13 then enables the injection of 
a resin cartridge 16 into the hole 15 using compressed air or any other 
means--see FIG. 4. 
The jack 14 is then actuated in the reverse direction so as to bring the 
drilling rod 4 completely back into the axis 3 to its initial position. An 
anchoring bolt may then be fitted. In the case of a drilling and bolting 
turret, this turret is pivoted so as to bring the bolting carriage into 
the axis of the drilled hole 15. 
The movable guide member 8 of the forward head 6, shown as a monobloc 
sliding member in the outline diagrams of FIGS. 1 to 4, comprises two 
separate members in the particular embodiment shown in FIGS. 5 to 9. These 
Figs. show, in a detailed manner, the forward head 6 with its body 7, its 
connection 17 for fastening to the turret or and its anchoring tongs 9. 
The movable guide member 8 comprises a first member 18 mounted slidably in 
the guideways 19 of the body 7 in a direction perpendicular to the axis 3. 
The sliding member 18 comprises the passage 11 which is traversed by the 
drilling rod 4. 
The second member of the movable guide 8 is a member 20 mounted pivotably 
on the body 7 about an axis of rotation 21 perpendicular to the axis 3, 
such that this member 20 is displaced in the same plane as the sliding 
member 18. The pivoting member 20 comprises the passage 12 provided with a 
connector 22 for the fastening of the end of the flexible cartridge 
injection hose 13--see FIGS. 7 and 8. 
The pivoting member 20, shown on its own in FIG. 9, comprises a central 
block 23 containing the passage 12 and mounted on a fork-shaped lever 24. 
This is pivotably mounted on two journals 25 located on either side of the 
body 7. The control jack 14 is articulated, on one hand, about an axis 26 
on the body 7 and, on the other hand, about an axis 27 on one of the two 
arms of the fork 24. 
The sliding member 18 is connected to the pivoting member 20 by means of 
two parallel connecting rods 28 articulated, on one hand, about a common 
axis 29 on the sliding member 18 and, on the other hand, about a common 
axis 30 on the central block 23 of the pivoting member 20. 
The jack 14 therefore controls the rotation of the pivoting member 20 about 
the axis 21 directly, and the pivoting member 20 transmits its movement, 
via the connecting rods 28, to the sliding member 18 in order to displace 
the latter along the slideways 19. 
FIGS. 5, 6 and 7 show the sliding member 18 and the pivoting member 20 in 
the drilling position. The passage 11 of the sliding member 18 is then 
centered on the axis 3, whereas the axis 31 of the passage 13 of the 
pivoting member 20 forms an angle (.alpha.), for example approximately 
35.degree., with the axis 3. In this drilling position, as shown in FIG. 
7, the end of the flexible injection hose 13 is sufficiently offset to the 
side to enable the nose of the drilling apparatus 2 to be brought very 
close to the forward head 6. 
In the injection position, shown in FIG. 8., the sliding member 18 is 
laterally offset so as to distance the drilling rod 4 from the axis 3 by 
bending, in accordance with the principle described above. The rotation of 
the pivoting member 20 has then brought the axis 31 of its passage 12 into 
alignment with the axis 3. 
FIGS. 7 and 8 show, moreover, that the body 7 of the forward head 6 
receives a detachable guide sleeve 32 which defines the guide aperture 10. 
In order to change the drilling diameter, it is simply necessary to 
replace the guide sleeve 32 by another sleeve and to replace the sliding 
member 18, the body 7 remaining in position. 
Finally, it should be noted that there is a free space 33 between the 
sliding member 18 and the pivoting member 20 which, if sufficiently large, 
enables the removal, under the effect of gravity, of rock debris and 
water, during passage from the drilling to the injection position. 
It is obvious that the invention is not limited to the single embodiment of 
this turret of a drilling apparatus described above by way of example. The 
invention covers all constructional and operational variants based on the 
same principle. Thus, it would not lie outside of the scope of the 
invention to use equivalent means, for example by replacing the jack by 
any other control means, or to vary the purpose of use of the invention 
and replace the resin cartridges by similar products.