GB2041423A - Excavating machines for excavating rock or mineral - Google Patents

Abstract

An excavating machine for excavating rock or mineral to extend an underground roadway or tunnel comprises a floor mounted base (1), a support assembly (2) mounted on the base, and a cutter-carrying boom (3) pivotally mounted on the support assembly, the support assembly comprising a boom supporting turret including two pivotally connected components (4, 5) one of which defines a rotary bearing (6) shaft (7) extending substantially longitudinally along the roadway or tunnel, the two components being pivotally connected to vary the inclination of the shaft axis relative to the roadway or tunnel floor (10). <IMAGE>

Description

SPECIFICATION Excavating machines for excavating rock or mineral to extend an underground roadway or tunnel This invention relates to excavating machines for excavating rock or mineral to extend an underground roadway or tunnel.

In particular the present invention relates to an excavating machine comprising a base moveable along the roadway or tunnel floor, a support assembly mounted on the base and a forwardly directed cutter-carrying boom pivotally mounted on the support assembly.

With such a prior known excavating machine the height of the pivotal mounting of the boom on the support assembly is fixed relative to the outer cut profile of the roadway or tunnel. Consequently, the machine is not always able to cut the most desirable shape of outer profile to suit the roof supports installed along the roadway or tunnel.

An object of the present invention is to provide an improved excavating machine which tends to overcome or reduce the above mentioned disadvantage.

According to the present invention an excavating machine for excavating rock or mineral to extend an underground roadway or tunnel, comprises a base moveable along the roadway or tunnel floor, a support assembly mounted on the base, and a cutter-carrying boom pivotally mounted on the support assembly, the support assembly comprising a boom supporting turret assembly including a first component mounted on the base and a second component providing a rotary bearing assembly for a shaft the axis which, in use extends substantially longitudinally along the roadway or tunnel, two components being pivotally connected to vary the inclination of the shaft axis relative to the roadway or tunnel floor.

Preferably, the two components are pivotally connected about an axis extending transverse to the longitudinal axis of the roadway or tunnel.

Advantageously, relative movement of the two components about the pivotal axis is controlled by a hydraulic ram.

Conveniently, a rotary drive mechanism provided at one end of the shaft and a boom support assembly provided at the other end of the shaft.

Preferably, the boom support assembly pivotally supports the boom.

Preferably, the first turret component is fixedly mounted on the base.

By way of example only, two embodiments of the present invention will be described with reference to the accompanying drawings, in which: Figure 1 is a side elevation of an excavating machine constructed in accordance with a first embodiment of the present invention; Figure 2 is a plan of Fig. 1; Figure 3 is an incomplete side elevation of a detail of an excavating machine constructed in accordance with a second embodiment of the present invention; Figure 4 is an incomplete front view of Fig.

3; Figure 5 is an incomplete side elevation of the excavating machine of Fig. 1, the machine being shown in one operational position; Figure 6 is an incomplete diagrammatic view looking along the roadway or tunnel formed by the excavating machine of Fig. 5; Figure 7 is an incomplete side elevation similar to Fig. 5 but showing the excavating machine in an alternative operational position; Figure 8 is an incomplete diagrammatic view looking along the roadway or tunnel formed by the excavating machine of Fig. 7; Figure 9 is an incomplete side elevation similar to Fig. 5 but showing the second embodiment of excavating machine; Figure 10 is an incomplete diagrammatic view looking along the roadway or tunnel formed by the excavating machine of Fig. 9.

Referring now to Figs. 1 and 2 of the drawings, the first embodiment of excavating machine for excavating rock or mineral from a working face to extend an underground roadway or tunnel comprises a floor mounted base 1 arranged to slide along the roadway or tunnel floor towards the working face as the roadway or tunnel is extended, the base comprising two parts relatively moveable under the action of hydraulic rams (not shown).

A support assembly 2 for a forwardly directed cutter-carrying boom 3 is mounted on the base 1, the support assembly comprising a turret assembly including a first component 4 fixedly mounted on the base and a second component 5 providing a rotary bearing assembly 6 for a shaft 7 the axis which, in use, extends substantially longitudinally along the roadway or tunnel, the two turret components 4 and 5 being pivotally connected by pivotal mounting 8 to vary the inclination of the shaft axis relative to the roadway or tunnel floor 1 0.

Relative pivotal movement of the two turret components 4 and 5 is controlled by a pair of hydraulic rams 11 connected between the two components.

The rear end of the shaft 7 is drivably engaged by a rotary drive mechanism 1 3 as described in detail in our co-pending prior British patent application No. 43098/78. The rotary drive mechanism 1 3 comprises two hydraulic rams 1 5 the cylinders of which are pivotally mounted on the rear of the second turret component 5 and the piston rods of which are pivotally connected to a slide member 1 6 pivotally mounted on the second turret component 5 and including a third hydraulic ram (not shown) arranged to urge a slide element to and fro along a slideway provided by the slide member 16, the slide element being drivably connected to a crank lever arranged to rotate the shaft 7 through one hundred and eighty degrees upon actuation of the rams which are double acting so that the shaft can be rotated first one hundred and eighty degrees in one direction and then one hundred and eighty degrees in the opposite direction. As explained in the co-pending application the three ram arrangement gives a substantially constant rotating force on the shaft throughout the full extent of rotational movement.

A boom support assembly 20 for the cuttercarrying boom 3 is drivably mounted on the front end of the shaft 7, the boom support assembly 20 comprising a pivotal mounting 21 for engagement by stub shafts 22 projecting from the boom 3 which carries a drive motor housing 23 for driving a rotary cutter 24 about a rotary axis extending longitudinally of the boom axis 25. Pivotal movement of the boom about the pivotal mounting 21 is controlled by a pair of hydraulic rams 27 connected between the boom 3 and the boom support assembly 20.

A loading apron (not shown) is provided at the front end of the base 1 beneath the boom 3, the loading apron being provided with reciprocating arms for urging cut rock or mineral from the roadway or tunnel floor towards a conveyor (not shown) extending through the base 1 towards further conveyor means extending outbye along the roadway or tunnel.

In operation, the excavating machine is located adjacent to the working face to be excavated by the cutter 24 to extend the underground roadway or tunnel. The base is advanced with the boom horizontal until the cutter 24 is sumped fully into the working face. The rams 11 have tilted the axis of the shaft 7 by a desirable amount as explained later in the specification. The rotary drive mechanism 1 3 is actuated to rotate the boom support assembly 20 together with the boom through ninety degrees so that the axis of the pivotal mounting 21 is vertical. The rams 27 then are actuated to displace the cutter 24 sideways by a distance substantially equal to the cutter diameter. The rotary drive mechanism 1 3 then is re-actuated to rotate the boom 3 through one hundred and eighty degrees, the cutter passing over the central sumping-in position.Upon completion of the boom swinging movement, the rams 27 are actuated further to displace the cutter further from the central position by a distance substantially equal to the diameter of the cutter which at this stage is spaced from the central position by a distance approximately equal to twice the cutter diameter. The rotary drive mechanism 1 3 then is re-activated to swing the cutter one hundred and eighty degrees over the central position in the opposite direction.

Upon completion of this cutting swing the cutter is displaced further from the central position and the cutting swing cycle repeated.

The whole of the above cutting cycle is repeated until the cutter has cut the outer curved profile associated with the upper portion of the working face.

The rams 11 then are actuated to pivot the second turret component 5 about the pivotal mounting 8 so that the boom support assembly 20 is moved downwards and the cutter 24 moves downwards by a distance substantially equal to the cutter diameter. The rams 27 are actuated to traverse the cutter horizontally across the working face towards the centre of the roadway or tunnel. Upon reaching a position approximately midway along the traverse the rotary drive mechanism 1 3 is actuated to rotate the boom 3 through one hundred and eighty degrees. The rams 27 then are re-actuated to complete the cutter's traverse across the working face.

The rams 11 are actuated to lower the cutter by a further distance substantially equal to the cutter diameter and the cutting traverse repeated so that the cutter is moved fully across the working face. This lowering and traversing cutting cycle is repeated until the cutter cuts rock or mineral to form the roadway or tunnel floor.

Upon the complete extraction of a strip of rock or mineral from the working face the excavating machine is advanced further along the roadway or tunnel to sump the cutter fully into the working face. Roof supports 30 (see Figs. 5, 6, 7 and 8) are installed before a further strip of rock or mineral is excavated.

Figs. 5 and 6 illustrate the excavating machine cutting a roadway or tunnel having a relatively large cross-section area suitable of or accepting relatively large sized standard roof supports. Typically the upper curved portion of the roadway or tunnel has a radius of eight feet. It will be seen in Fig. 5 that while the cutter 24 is arcing to cut the extreme outer curved profile the axis of the shaft 7 is arranged substantially horizontal.

Figs. 7 and 8 illustrate the excavating machine cutting a working face to form a roadway or tunnel having a relatively small cross-sectional area. Typically the upper curved profile of the roadway or tunnel has a radius of approximately six feet. In order to form such a relatively small roadway or tunnel it will be seen in Fig. 7 that the axis of the shaft 7 is titled downwardly forwardly during the arcing to form the curved profile. Such a procedure enables the excavating machine to form a roadway or tunnel suitable for accepting relatively small sized standard roof supports.

From Figs. 6 and 8 it can be seen that a curved floor is formed with this excavating machine. However, the amount of curvature is within acceptable limits for underground workings.

Figs. 3, 4, 9 and 10 relate to the second embodiment of excavating machine in which the cutter 24 of the first described embodiment is replaced by a cutter assembly comprising rotary twin cutters 40 arranged to rotate about an axis transverse to longitudinal axis of the boom 3, the cutters being driven by a drive motor carried by the boom 3 via a gearbox 41. All the other components of the excavating machine are as described with reference to the first embodiment.

It will be appreciated from Fig. 10 that this second embodiment of excavating machine can cut a more desirable lower portion of the cross-sectional area of the roadway or tunnel without outwardly extending cut outs. However, the cutter 40 does tend to leave a saw tooth like formation longitudinally along the roadway or tunnel.

Claims (10)

1. An excavating machine for excavating rock or mineral to extend an underground roadway or tunnel, comprising a base moveable along the roadway or tunnel floor, a support assembly mounted on the base, and a cutter-carrying boom pivotally mounted on the support assembly, the support assembly comprising a boom supporting turret assembly including a first component mounted on the base and a second component providing a rotary bearing assembly for a shaft the axis which, in use extends substantially longitudinally along the roadway or tunnel, the two components being pivotally connected to vary the inclination of the shaft axis relative to the roadway or tunnel floor.

2. An excavating machine as claimed in claim 1, in which the two components are pivotally connected about an axis extending transverse to the longitudinal axis of the roadway or tunnel.

3 An excavating machine as claimed in claim 1 or 2, in which relative movement of the two components about the pivotal axis is controlled by a hydraulic ram.

4. An excavating machine as claimed in claim 1, 2 or 3 comprising a rotary drive mechanism provided at one end of the shaft and a boom support assembly provided at the other end of the shaft.

5. An excavating machine as claimed in claim 4, in which the boom support assembly pivotally supports the boom.

6. An excavating machine as claimed in any one of the preceding claims, in which the first turret component is fixedly mounted on the base.

7. An excavating machine as claimed in any one of the preceding claims including a rotary cutter mounted on the boom, the cutter being driven by drive motor means carried by the boom.

8. An excavating machine as claimed in claim 7, in which the rotary axis of the cutter extends longitudinally relative to the boom.

9. An excavating machine as claimed in claim 7, in which the rotary axis of the cutter extends transversely relative to the boom.

10. An excavating machine for excavating rock or mineral to extend an underground roadway or tunnel, substantially as described with reference to the accompanying drawings.