GB2148357A - Shield apparatus for use in tunnelling or mining - Google Patents

Abstract

Shield apparatus 1 for driving tunnels has elongate drive members 12 displaceably supported on frames 4. Each frame 4 has an arched upper portion 6 connected via lifting devices 8 to a pair of foot units 7 disposed alongside the side walls of the tunnel. A central base framework 29 including a transverse floor beam 13 supporting a cutting machine 14 and conveyor 20 is disposed between the foot units 7. Adjustment devices 22 which act by mechanical wedging action, are disposed between the floor beam 13 and the foot units 7 and serve to displace the latter outwardly and inwardly selectively to brace the foot units against the tunnel walls. <IMAGE>

Description

SPECIFICATION Shield apparatus for use in tunnelling or mining The present invention relates to apparatus for use in driving tunnels, galleries, adits or similar underground excavations, such as roadways for mineral mine workings, referred to hereinafter simply as tunnels.

Apparatus of the type with which the invention is concerned is described in US patent specification 4173421. As described therein, the apparatus employs a shield with elongate drive members mounted side-to-side and supported for longitudinal displacement on frames. The drive members and frames are advanced alternatively as the tunnel progresses with the aid of hydraulic rams in known manner. The shield is of arcuate or domed shape defining the roof and side walls of the tunnel while a bracing structure at the floor extends across the tunnel. The shield can be expanded or contracted with the aid of hydraulic devices to brace the shield against the roof and side walls at will.

A general object of the present invention is to provide an improved shield apparatus.

According to the invention there is provided apparatus for driving tunnels or the like, said apparatus comprising frame means supporting a plurality of elongate drive members for longitudinal displacement, said frame means having an arcuate upper portion connected with lifting devices to lower foot units spaced apart laterally of the apparatus, a base framework located between the foot units and adjustable mechanical wedge devices for displacing the foot units outwardly and inwardly relative to the base framework. In contrast to the apparatus described in US patent specification 4173421, the piston and cylinder units used to displace the floor units or structures outwardly or inwardly are replaced by inexpensive wedge devices of particularly compact dimensions.The comparatively large displacements produced by the known piston and cylinder units are not necessary in all cases and it has been found that mechanical devices with a limited range of displacement are adequate in most applications. In a preferred form the adjustment devices have conical or frusto-conical components which inter-engage in wedging manner and act on a spring component such as an annular cage surrounding them. Such devices are known per se. A screw member, for example, can cause the conical components to move together or apart to thereby expand or contract the spring 20 component. These devices can be positioned between abutments on the base framework and walls of the foot units which, as known from US 4173421 can be box-like hollow structures.Only a comparatively small range of expansion and contraction is provided by the adjustment devices but this is sufficient to achieve the necessary lateral bracing.

Since the preferred adjustment devices are especially compact they can be easily accommodated in small compartments in the base structure of the apparatus.

Conveniently, the conical components are mounted in an upright position to permit the adjustment screw to the operated without difficulty from above.

The foot units may slidably rest on horizontal slide members of the base framework. It is possible to lock the foot units to the slide members therebeneath in the longitudinal sense while permitting the necessary lateral displacement. This will ensure that when the frame means is advanced the foot units will cause the base framework to move also.

Floor cutters advanceable in a similar manner to the drive members, can be suspended beneath the slide members and engage on the floor of the tunnel. The base framework may include at least one rigid transverse beam disposed above the floor.

The base framework can take various forms but it is preferred to provide guide means between the foot units and the base framework for relative guiding displacement longitudinally of the apparatus i.e. in the direction of tunnel advancement at least to a limited extent. The base framework can, for example, have hook-like pieces which engage over rails on the foot units. The outward bracing displacement of the foot units effected by the adjustment devices serves to disable the guide means and clamp the base framework to the braced foot units. The guide means may thus incorporate stops which limit the outward motion of the foot units. The resultant rigid braced floor structure is especially useful when, as is normal, a cutting machine for actually removing material from the working face is supported on the base framework.

The arcuate upper portion or portions of the shield may be connected to the associated foot units via hydraulic piston and cylinder units as is known.

The invention may be understood more readily, and various other aspects and features of the invention may become apparent, from consideration of the following description.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings wherein: Figure 1 is a schematic section side view of apparatus constructed in accordance with the invention; and Figure 2 is a partial cross-section through the apparatus shown in Figure 1.

As shown in the accompanying drawings, apparatus constructed in accordance with the invention utilises a displaceable shield 1 having a generally part-cylindrical or horse-shoe shaped profile. This shield 1 is composed of frame means 2 supporting a plurality of elongate drive members 12 for individual displacement in the longitudinal direction.

As is know, these drive members 12 contact the roof and side walls of a tunnel or similar excavation having a cross-section as shown in Figure 2.

The frame means 2 is itself composed of individual frames 3 and 4 disposed one behind the other in the direction of advancement of the tunnel. The frames 3, 4 are interconnected for example, by means of resilient longitudinal struts or connectors or by means of a sheet metal cowl or casing 5. As is known, double-acting hydraulic rams (not shown) are connected between the frames 3, 4 and the drive members 12 and these rams can be operated collectively, individually or in groups to effect advancement of one or more of the members 12 or, 10 alternatively, collectively to advance the frames 3, 4. In this way the members 12 can be advanced and then the frame means 2 drawn up in known manner.

The drive members 12 are mounted with the aid of guide means on the frames 3, 4 for longitudinal displacement and this guide means can take the form of tongue-and-groove type connections 11.

The individual frames 3 and 4 are essentially similar in construction. Each frame 3, 4 is composed of an arcuate upper portion 6 and two foot units 7 disposed on opposite sides of the 20 tunnel. The portions 6 can each be sub-divided with roof joints as described in US patent specification 4173421.

The units 7 take the form of hollow box-like structures and have upstanding supports 9 to which piston and cylinder units 8 are attached with the aid of pivot joints 10. The piston rods of these units 8 are connected to the upper portion 6 of the frames 3, 4 with the aid of further pivot joints 10'.

The units 8 can be operated to raise and brace the upper portion 6 against the roof of the tunnel.

The units 7 of the frames 3, 4 are adjustably interconnected to one or more transverse floor beams 13 or the like which form at least part of a stable central base framework 29 which supports a drifting machine 14. As is known, the machine 14 operates as a partial cutting machine and has a swinging arm 15 supporting a driven cutting head 16 which detaches material from the working face in front of the shield 1. The machine 14 is itself supported for movement along the shield 1 by means of guides 17 mounted on the base framework. Piston and cylinder units 18 are used to displace the machine 14 back and forth within the shield 1.

As can be seen in Figure 1, the front of the base framework 29 also carries a loading mechanism 19 which serves to transfer material detached by the cutting head 16 onto a loading conveyor 20 also mounted on the base framework 29. Conveniently, the conveyor 20 is mounted above the floor 21 of the tunnel in an inclined disposition between the units 7 of the frames 3, 4. As mentioned, the boxlike units 7 are connected to the base framework 29 for adjustment and more particularly for displacement outwardly or inwardly relative to the tunnel walls as is known, per se, from US patent specification 4173421. In the embodiment, as illustrated, the units 7 have bases which rest on slide members 30 connected to the base framework 29.

The members 30 adjoin upstanding abutments 31.

The base framework 29 has guides 26 which engage in hook-like manner around strips 28 on the uppersides of the units 7 to permit relative displacement between the framework 29 and the units 7 of the frames 2, 3 along the tunnel. Adjustment devices 22 are interposed between the abutments 31 and the units 7 and serve to expand the units 7 selectively in a direction transversally outwardly against the sides of the tunnel. The devices 22 are wedge devices each having upstanding interengageable conical parts 23 within a split spring cage 24 which can be selectively expanded and contracted radially by moving the parts 23 inwardly and outwardly of one another. A screw member 25, which can be moved manually or with the aid of a motor, serves to selectively expand or contract each device 22 to thereby move the units 7 outwardly or inwardly relative to the stationary base framework 29.

The slide members 30 at the front of the apparatus have on their underside guide rails which receive guide blocks of floor cutters 32. As illustrated, in a preferred embodiment, two such floor cutters 32 are located adjacent one another on either side of the apparatus. The cutters 32 rest on the floor 21 of the tunnel and effectively support the shield 1. Hydraulic rams are used to drive the floor cutters 32, forwardly in a similar manner to the drive members 12.

It can be appreciated that with the aid of the devices 22, the units 7 can be braced against the tunnel walls and clamped in this position. The units 8 can likewise be extended to brace the upper portions 6 of the frames 2, 3 against the tunnel roof.

The adjustment of the units 7 in the outward direction is limited by the engagement of effective stops formed between the guide parts 27, 28. Thus outward displacement of the units 7 also clamps the base framework 29 and prevents its longitudinal displacement. The devices 22 can be operated to release the units 7 when it is desired to shift the frames 2, 3 to a new position and the units 8 retract as necessary. The effective width of the frames 3, 4 at the floor region can be adjusted with the aid of the devices 22 so that, overall, the shield 1 can be adapted to the prevailing conditions in the tunnel driving operation.

It is advisable to provide a plurality of devices 22 between the base framework 24 and each unit 7.

One common continuous unit 7 can also be used at each side of the shield for linking both frames 3 and 4. It is also possible for each frame 3, 4 to be provided with separate units 7 as described but to additionally interconnect the units 7 at each side by further longitudinal connectors.

Claims (13)

1. Apparatus for driving tunnels or the like, said apparatus comprising frame means supporting a plurality of elongate drive members for longitudinal displacement, said frame means having an arcuate upper portion connected with lifting devices to foot units spaced apart laterally of the apparatus, a base framework located between thefoot units and adjustable mechanical wedge devices for displacing the foot units outwardly and inwardly relative to the base framework.

2. Apparatus according to claim 1, wherein the frame means is composed of two frames spaced apart longitudinally of the apparatus, each frame having one said arcuate upper portion connected to the foot units.

3. Apparatus according to claim 2, wherein each frame has a pair of laterally-spaced foot units connected with the lifting devices to its upper port and the adjustable devices are provided between each foot unit and the base framework.

4. Apparatus according to any one of claims 1 to 3, wherein the base framework has one or more transverse beams.

5. Appararus according to any one of claims 1 to 4, wherein each adjustment device has interengaging conical parts which are displaced relatively and a spring 2 component which surrounds these parts.

6. Apparatus according to claim 5, wherein the conical parts are upstanding.

7. Apparatus according to any one of claims 1 to 6, wherein each adjustment device has a screwthreaded member for effecting the adjustment.

8. Apparatus according to any one of claims 1 to 7, wherein the base framework and the foot units have co-operating guides which render the framework relatively displaceable longitudinally of the apparatus but which are clamped by operation of the adjustment devices.

9. Apparatus according to any one of claims 1 to 8, wherein the foot units slidably engage on horizontal slide members of the base framework which adjoin upstanding abutments and wherein the adjustment devices are positioned between the abutments and the foot units.

10. Appararus according to any one of claims 1 to 9, wherein the base framework has guides which displaceably support floor cutters.

11. Apparatus according to any one of claims 1 to 10, wherein the base framework supports at least a cutting machine.

12. Apparatus according to any one of claims 1 to 11, wherein the base framework has one or more transverse beams and the adjustment devices are interposed between the beam or beams and the foot units.

13. Apparatus substantially as described with reference to, and as illustrated in the accompanying drawings.