Note: Descriptions are shown in the official language in which they were submitted.
issue
CIRCULAR HEADING MACH IRE
This invention relates to circular heading machines for
excavating tunnels.
It is well known to cut tunnels by advancing a machine in
step-wise fashion and to erect tunnel supports behind the
machine. However, as these supports are behind the machine, the
machine itself is protected by some other means such as shields,
but shields can become trapped by convergence, especially in deep
mining and consequently tunneling can be delayed while the shield
is freed.
According to one aspect of the present invention, there
is provided a circular heading machine comprising an elongate
machine body, means to advance said body in stops fashion, a
carriage mounted on top of the machine body and slid ably movable
thereon longitudinally and independently of the stops movement
of the machine body, a forwardly directed cutter boom mounted on
the sliding carriage and manually controlled from an operative
position on the sliding carriage, a cage structure surrounding the
sliding carriage, and means for erecting tunnel support structures
over the machine body, the erecting means being provided
externally of the cage structure whereby the cutter boom operative
can operate the cutter boom during erection of the tunnel support
structures so that erection of the tunnel support structures and
operation of the cutter can take place simultaneously as the
machine advances in stops fashion.
Preferably, the hood is a semi-circular member supported
by hydraulic rams for height adjustment.
An embodiment of the present invention will now be
described, by way of example, with reference to the accompanying
drawings in which:
TV
isles
-- 2 --
Fig. 1 is a side elevation of a circular heading
machine according to the invention;
Fig. 2 is a plan view of Fig. l;
Figs. 3 to 5 are side elevations of the machine
illustrating, with Fig. 1, the cycle of operation;
Fig. 6 is a rear elevation of the lines VI-VI of
Fig. 1 showing tunnel support erection apparatus.
Fig. PA is a rear elevation of the lines VIVA of
Fig. 1 showing the rear support leg
Fig. 7 is a detail illustrating lagging between
the tunnel supports; and
Fig. 8 is a detail illustrating a trailing arm.
The circular heading machine has an elongate body
10 which mounts a cutter boom 11 at its forward end,
the boom 11 being carried on a sliding carriage 12 which
is slid ably movable on the machine body 10 by thrust
jacks 13. The cutter boom 11 carries a conical cutter
head 14, by which a tunnel 15 can be excavated; movement
of the boom is manually controlled via tilting jacks
2G lea and stewing jacks lob, by an operator seated in
the sliding carriage.
At the forward extremity of the machine body there
is a gathering apron 16 of semi-circular form which
carries windmill or gathering arms AYE and above the
apron there is a semi-circular hood 17; this hood forms
a stone/dust guard as illustrated in Fig. 1 for use
as a temporary roof support if required and it may be
provided with trailing fingers (Fig. 8) as hereinafter
described.
The hood is supported by hydraulic rams AYE which
serve to lower the hood if necessary for the insertion
of lagging strips 45 twig. 6) hereinafter described
and to permit controlled lowering of the hood in the
event of severe convergence or collapse of the roof.
The apron and hood converge rearward and terming
'I .
~235~50
-- 3
ate in a profile guidance ring 18 and on the cutter
boom there is a profile collar 18' which can run round
the inner face of the ring 18 thus limiting the movement
of the boom.
Immediately behind the apron/hood structure is a
tunnel-support mechanical erection apparatus 20 by which
ring girders can be erected over the machine body as
hereinafter described with reference to Fig. 6.
A cage-structure 21 is provided on the machine
body below the level of the top of the hood 17 to
enclose the boom 11 and carriage 12 and the support
erection apparatus 20 is external of the cage 21.
Tunnel support erectors can therefore work in safety
on a platform 22 on the machine body even while the
cutter 14 is in operation.
Towards the rear of the machine body 10, a radial
gripper mechanism 23 is provided having three segmental
grippers 24 which are radially extendible to engage the
sides and floor of the excavated tunnel. Thrust jacks
25 and AYE are connected between the lowermost gripper
24 and an under frame 26 on the machine body 10 and
between side grippers 24 and longitudinal beams AYE
also on the machine body. When the grippers 24 are
firm against the tunnel, the jacks 25 and AYE can extend
US to push the machine body forward; when the grippers are
retracted the jacks 25 and AYE can be retracted to draw
the gripper mechanism 23 forward.
Rearward of the gripper mechanism a segmental
support leg 27 is mounted on the machine body 10 and
is extended downwards to engage the tunnel floor when
the gripper mechanism is to be retracted and when the
side grippers are being adjusted to align the machine
transversely, thus to hold the machine in its existing
vertical alignment. The support leg 27 is part of a
centering structure AYE which is transversely slid ably
lZ35~50
-- 4 --
mounted in the machine body 10 and includes side jacks
27B. The jacks 27B operateseq~ntially with support
leg 27 to ensure that the latter is automatically
centralized in the tunnel before engaging the tunnel
floor.
To achieve this the side jacks 27B which are
hydraulic jacks are connected through an equal split
flow divider so that their flows are equal; thus if one
jack engages the tunnel wall first, it will push the
entire jack structure transversely relative to the
machine body away from that side until the other side
jack engages its side of the tunnel, after which the
support leg 27 will be in a centered position relative to
the tunnel. Once the support leg has been lowered, the
rear end of the machine body can be transversely ad-
jutted via the side grippers 24 to give accurate direct-
tonal positioning of the machine required, as herein-
after explained.
The machine body carries an integral scraper
chain conveyor section 30 which runs from the gathering
apron, under the machine body then upwardly towards
the rear end, exiting in a rearward extension 31 beyond
the machine body for transfer of excavated minerals to
a bridge conveyor 32 trailed by the machine. The bridge
conveyor is aligned below conveyor extension 31 and on
the former is slid ably mounted a deflector structure
AYE which when in one position is clear of material
dropping on to the bridge conveyor 32 and when in the
other position deflects the material on to the floor
at the side of the bridge conveyor to create an inflow
33 when required.. The machine operates in cycles as
illustrated in Figs. 1 and 3 to 5, and described herein-
after.
Tunnel support erection is carried out by erectors
working on the platform 22 situated immediately behind
lZ35iSO
-- 5
the apron/hood structure so that the supports are
erected over the machine body and in advance of the boom
operator. A secondary platform AYE is provided on
each side for erectors to fit tie rods 52 hereinafter
described.
Segments of ring girders 40 (Figs. 1 and 6) are
delivered, e.g. by monorail (not shown) to the rear of
the machine and delivered therefrom via a hydraulically
driven chain hauled carrier 41 (Fig. 6) running via
wheel 42 on a longitudinal structure 43 overlying the
machine body to the erection area behind the hood 17.
Structure 43 is bodily adjustable longitudinally and
vertically relative to the machine body 10 by hydraulic
rams 44 and 45 (Fig. 1) to manipulate the ring supports
into position. At the erection area directly behind
the apron/hood all but one of the segments 40 are
mounted in turn on the mechanical erector 20 which is
a framework carrying a circular chain 46 (Fig. 6)
driven by sprockets 47 then jointed and hauled round the
tunnel perimeter until an almost complete but collapsed
ring has been built. Over the top half section
lagging in the form of wire mesh panels or corrugated
sheets 48 is introduced between the last panel of
lagging and the new collapsed ring girder by inserting
them alternately into arcuate slot 49 and space 50 and
raising them to overlap the previous set.
Those sections of the ring girder now in position
are expanded by the maneuvering adjustment of structure
43 to trap the lagging 4B and to meet the perimeter
of the lower part of the tunnel; thus the final section
of the ring girder is placed in position on carrier 41
and by advancing the carrier is presented against the
as yet unexpanded ring portions already in position.
At this stage adjustable legs 51 of the carrier 41 are
manually brought out and locked against the ends of
35~50
the positioned sections 40 and the entire structure 43
is lifted by hydraulic rams 45 to expand the positioned
sections radially to provide room for the final section
which is advanced into position either by moving strut-
use 43 bodily forward using hydraulic rams 44 or by
advancing carrier 41 or both.
A ring expansion joint (not shown) is then fitted
and to give extra tunnel support the machine is designed
to allow this expansion joint to be located in different
positions on adjacent ring girders so that the weakest
point in the girder is not always in the same relative
position.
The tie rods 52 (Fig. PA) are loosely bolted to
the previous ring and the entire new ring is drawn back
on carrier 41 by the hydraulic rams 44 to abut against
the tie rods.
The new ring is then loosely bolted to the tie rods
after which a final expansion of the new ring is carried
out using known methods, e.g. mechanical screw jacks
and final tightening of the bolts is made.
cycle.
The machine operates in cycles as illustrated in
Figs. 1 and 3 to 5 (in the latter Figs. the jacks AYE
are omitted for reasons of clarity).
before beginning the cycle and with the entire
machine advanced to the face:
1. The boom sliding carriage 12 is in its retracted
position so that the cutter 14 is just clear of
the mineral face.
2. The side jacks AYE are extended to automatically
centre the lower support leg 27 in the tunnel and
then lower it to the floor.
3. The gripper mechanism 23 is retracted chain lines)
and drawn forward by retraction of the thrust
jacks 25 and AYE.
-
sluice
-- 7
4. The transverse alignment of the machine 10 is
checked by known methods of alignment, erg. laser
beams 53 and target 54 on the machine and if
necessary set to its correct position by pushing
with the left hand or right hand wall gripper AYE
against the tunnel wall thus sliding the machine
across the centering structure AYE which is
firmly located against the tunnel wall.
5. The wall grippers AYE are then retracted and the
floor gripper 24 is lowered followed by retraction
of the lower support leg 27 and side jacks AYE
and the vertical alignment is checked by the same
means as (4) above using the floor gripper.
6. With the floor gripper 24 still in position both
side grippers AYE are then set hard against the
tunnel walls.
7. Lagging 48 (Fig. 6) is introduced into arcuate slot
49 and into the space 50 between the hood 17 and
the roof and a ring girder 40 is assembled and
expanded finally thus trapping this lagging between
girder and tunnel. The machine is now ready to cut
into face 35.
8. The cutter boom carriage is advanced to sampan the
cutter head and excavate to a depth of 0.5 moire
(Fig. 1). The head can move universally within the
limits set by the profile ring 18 and forms a circus
far hole slightly in excess of the required tunnel
diameter with a new mineral face AYE.
9. Whilst this operation is in progress a set of ring
segments are brought forward from the rear, loaded
into the erector 20 and carried round into position.
10. After that excavation, the cutter boom carriage is
retracted and the machine advanced 0.5 moire carry-
in the partially assembled ring in the erector
with it to once again present the cutter head to
1~35150
the mineral face now AYE. During this time the
lagging 45 covers the 'exposed' ground by bridging
between the initial set ring and the hood.
11. The carriage is then advanced again (Fig. 4) to
sup in and excavate another OHS moire to form a
new mineral face 35B.
12. After that excavation the carriage is retracted and
the machine advanced a further 0.5 moire (Fig. 5)
thus having achieved the first 1.0 moire advance of
the machine.
13. The cycle for 1.0 moire advance is now completed
with the cutter 14 just clear of the mineral face
35B. The gripper mechanism 23 is released, drawn
forward and repositioned.
lo. The cycle can now be repeated but steps 7 and 8
are combined so that in the process of excavating
the next 0.5 moire, lagging is positioned around
the hood again to overlap the existing lagging,
the last ring segment is loosely fitted, and the
tie rods 52 are secured between the first and
second rings as previously described. The entire
ring is positioned by maneuvering structure 43
then expanded finally into position.
In an alternative hood construction, Fig. 8
rearwardly extending fingers 55 are resiliently connected
to the front edge of each hood plate 17 and extend back
by such a length that they overlie not only the ring
girder being erected but also the last fully erected
ring girder. When the machine reaches the end of
its cycle, the structure 43 is maneuvered to position
the ring girder being erected and during the new cycle
when the machine is pushed forward the trailing fingers
47 are drawn clear of the previously last erected ring
girder to overlie the new last erected ring girder.
Dust extraction ducts 56 are fastened to the
SUE
g
machine body whereby when air is blown into the tunnel
and over the machine, dust from the excavation will be
drawn into the top of hood 17 and through the ventilation
ducts 56 to exit from the rear into a dust collection
unit (not shown) thus enabling the erectors to operate
in a relatively dust free atmosphere.
A hydraulic power pack 57 can be trailed behind
the machine or, as illustrated in Fig. 1 located on the
machine body and is used to power all the machine's
functions.
In the preferred embodiment three radial grippers
24 are provided, i.e. the two side grippers plus the
floor gripper. However, should conditions require it,
a fourth gripper may be added to engage the roof in
conjunction with the side and floor units. There are
removable parts in the gripper shoes 24 which allow the
grippers to 'straddle' the ring girders if any increase
or decrease in ring density is required.
In addition the apron 16 and hood 17 have alternate
ivy bolting positions so that tunnels of varying die-
meters within the limits of plus or minus 0.25 metros from
the norm may be worked.
An advantage of the circular mining machine as
herein before described is that it allows erection of the
tunnel support structure over the machine rather than
behind it, thus reducing the 'prop-free front distance',
i.e. the distance between the cut face and the last
permanent tunnel support. Further in the event of con-
virgins, the only part of the machine that can become
trapped is the hood 17, and another advantage, due to
the feature of the boom carriage being movable in depend-
entry of the machine, is that in the event of sudden
convergence trapping the machine against further forward
movement, the cutter can be advanced to cut a chamber and
the mineral cut thereby can then be removed by hand by
1;~35~50
-- 10 --
personnel gaining access to the mineral through the cage
and apron/hood.
A further advantage of the circular heading machine
as herein before described is its economic rate of
advance, cutting 1 moire in each cycle in two cuts of
0.5 moire, while simultaneously allowing support erect-
ion operations to be carried out in safety.
