GB2168735A

GB2168735A - Tunnel drive shield

Info

Publication number: GB2168735A
Application number: GB08531323A
Authority: GB
Inventors: Dieter Stuckmann; Hans Schigulski
Original assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Current assignee: Gewerkschaft Eisenhutte Westfalia GmbH
Priority date: 1984-12-22
Filing date: 1985-12-19
Publication date: 1986-06-25
Also published as: GB2168735B; FR2582347B1; IT1188075B; JPS61155593A; ES296554Y; DE3447120A1; FR2582347A1; IT8515278V0; ES296554U; GB8531323D0; BE903922A; IT8512619A0

Abstract

A knife shield (1) is disclosed for use in driving tunnels. The knife shield (1) has a framework (2) supporting a plurality of knives (3) which are arranged side-by-side around the framework. The knives (3) are extendable in the driving direction relative to the framework (2). Each of the elongate knives (3) is provided with an additional, external knife (5). <IMAGE>

Description

SPECIFICATION Tunnel drive shield This invention relates to a drive shield for use in driving tunnels, galleries, adits and similar cavities.

A known type of tunnel drive shield (known as a knife shield) has a framework supporting a plurality of elongate, sharp-ended members (knives) which are arranged side-by-side around the framework.

The knives are extendable in the driving (axial) direction relative to the framework. Such a knife shield has the disadvantage that a specific shield has to be used for each tunnel cross-section to be driven. Subsequent alteration of the cross-section, for example by increasing the diameter of a tunnel, is not possible with shields of this known type.

A known knife shield of this type includes spreaders interposed between the framework and the knives. The spreaders rest against the framework, and are advanced together with the framework in the driving direction as soon as the knives (which are movable relative to the spreaders) are advanced. The knives can be advanced, either individually or in groups, relative to the spreaders and the framework. Although the diameter of a knife shield can be altered slightly using such spreaders, the spreaders are not suitable for appreciably increasing the diameter of the shield. The spreaders serve, rather, to compensate for any knife convergences which might occur during prolonged stoppages in ground which exerts high pressure on the shield, and to prevent jamming of the knives.

It is also known to provide the knives with separate blade members, these blade members being fixed to the knives by means of screw bolts.

These additional blades can be outwardly inclined, and thus temporarily alter the cross-section to be driven, thereby allowing control of the knife shield.

The aim of the invention is to provide a drive shield which is suitable for driving tunnels, galleries or adits with cross-sections of varying size.

The present invention provides a drive shield for use in driving tunnels, the drive shield having a framework supporting a plurality of elongated members which are arranged side-by-side around the framework, the elongate members being extendable in the driving direction relative to the framework, wherein each of the elongate members is provided with an additional, external elongate member.

Advantageously, each additional elongate member is constituted by a curved external metal sheet and a curved internal metal sheet, the external and internal metal sheets being connected via webs and an end metal sheet. Preferably, the end metal sheet of each additional elongate member is provided with apertures for the passage of screwthreaded bolts.

In a preferred embodiment each additional elongate member is connected to the associated elongate member by screw-threaded bolts passing through the internal metal sheet of that additional elongate member. Alternatively, each additional elongate member is welded to the associated elongate member.

Drive shields of this type allow tunnels having differing diameters and cross-sections to be driven in succession, as the additional elongate members fixed to the outsides of the elongate members alter the diameter of the shields.

Atunnel drive shield constructed in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. lisa side elevation of the drive shield; Fig. 2 is a perspective view of an additional knife of the drive shield; Fig. 3 is a cross-section taken on the line I-I of Fig. 1; and Fig. 4 shows detail Xfrom Fig. 3 on an enlarged scale.

Referring to the drawings, Fig. 1 shows a knife shield 1 having a framework 2 and a plurality of knives 3. The knives 3 are arranged side-by-side around the periphery of the framework 2, and each is movable relative to the framework in the direction of the longitudinal axis thereof (the driving direction). Each of the knives 3 can be advanced, relative to the framework 2, by means of a respective hydraulic ram 4 in known manner. A tunnel of diameter d can be driven with a knife shield of this design. If the diameter of the tunnel to be driven is to have a diameter D, additional knives 5 can be fixed to the knives 3.

As shown in Fig. 2, each additional knife 5 comprises an external curved metal sheet 6, and an internal curved metal sheet 7. The external metal sheet 6 and the internal metal sheet 7 are connected via compensating webs 8 and 9. Each additional knife 5 also includes a metal end sheet 10 provided with apertures 11 forthe passage of screw-threaded bolts.

As shown in Fig. 4, the additional knives 5 are fitted over the knives 3 with their internal metal sheets 7 fixed thereto by screw-threaded bolts 12.

Additional knives 5 of differing thicknesses can be used to allow tunnels of differing diameters to be driven with the same knife shield 1.

As an alternative to the fixing of the additional knives 5 using bolts 12, it would be possible to weld the additional knives to the knives 3.

1.A A drive shield for use in driving tunnels, the drive shield having a framework supporting a plurality of elongate members which are arranged side-by-side around the framework, the elongate members being extendable in the driving direction relative to the framework, wherein each of the elongate members is provided with an additional, external elongate member.

2. A drive shield as claimed in claim 1, wherein each additional elongate member is constituted by a curved external metal sheet and a curved internal metal sheet, the external and internal metal sheets being connected via webs and an end metal sheet.

3. A drive shield as claimed in claim 2, wherein the end metal sheet of each additional elongate member is provided with apertures for the passage of screw-threaded bolts.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Tunnel drive shield This invention relates to a drive shield for use in driving tunnels, galleries, adits and similar cavities. A known type of tunnel drive shield (known as a knife shield) has a framework supporting a plurality of elongate, sharp-ended members (knives) which are arranged side-by-side around the framework. The knives are extendable in the driving (axial) direction relative to the framework. Such a knife shield has the disadvantage that a specific shield has to be used for each tunnel cross-section to be driven. Subsequent alteration of the cross-section, for example by increasing the diameter of a tunnel, is not possible with shields of this known type. A known knife shield of this type includes spreaders interposed between the framework and the knives. The spreaders rest against the framework, and are advanced together with the framework in the driving direction as soon as the knives (which are movable relative to the spreaders) are advanced. The knives can be advanced, either individually or in groups, relative to the spreaders and the framework. Although the diameter of a knife shield can be altered slightly using such spreaders, the spreaders are not suitable for appreciably increasing the diameter of the shield. The spreaders serve, rather, to compensate for any knife convergences which might occur during prolonged stoppages in ground which exerts high pressure on the shield, and to prevent jamming of the knives. It is also known to provide the knives with separate blade members, these blade members being fixed to the knives by means of screw bolts. These additional blades can be outwardly inclined, and thus temporarily alter the cross-section to be driven, thereby allowing control of the knife shield. The aim of the invention is to provide a drive shield which is suitable for driving tunnels, galleries or adits with cross-sections of varying size. The present invention provides a drive shield for use in driving tunnels, the drive shield having a framework supporting a plurality of elongated members which are arranged side-by-side around the framework, the elongate members being extendable in the driving direction relative to the framework, wherein each of the elongate members is provided with an additional, external elongate member. Advantageously, each additional elongate member is constituted by a curved external metal sheet and a curved internal metal sheet, the external and internal metal sheets being connected via webs and an end metal sheet. Preferably, the end metal sheet of each additional elongate member is provided with apertures for the passage of screwthreaded bolts. In a preferred embodiment each additional elongate member is connected to the associated elongate member by screw-threaded bolts passing through the internal metal sheet of that additional elongate member. Alternatively, each additional elongate member is welded to the associated elongate member. Drive shields of this type allow tunnels having differing diameters and cross-sections to be driven in succession, as the additional elongate members fixed to the outsides of the elongate members alter the diameter of the shields. Atunnel drive shield constructed in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. lisa side elevation of the drive shield; Fig. 2 is a perspective view of an additional knife of the drive shield; Fig. 3 is a cross-section taken on the line I-I of Fig. 1; and Fig. 4 shows detail Xfrom Fig. 3 on an enlarged scale. Referring to the drawings, Fig. 1 shows a knife shield 1 having a framework 2 and a plurality of knives 3. The knives 3 are arranged side-by-side around the periphery of the framework 2, and each is movable relative to the framework in the direction of the longitudinal axis thereof (the driving direction). Each of the knives 3 can be advanced, relative to the framework 2, by means of a respective hydraulic ram 4 in known manner. A tunnel of diameter d can be driven with a knife shield of this design. If the diameter of the tunnel to be driven is to have a diameter D, additional knives 5 can be fixed to the knives 3. As shown in Fig. 2, each additional knife 5 comprises an external curved metal sheet 6, and an internal curved metal sheet 7. The external metal sheet 6 and the internal metal sheet 7 are connected via compensating webs 8 and 9. Each additional knife 5 also includes a metal end sheet 10 provided with apertures 11 forthe passage of screw-threaded bolts. As shown in Fig. 4, the additional knives 5 are fitted over the knives 3 with their internal metal sheets 7 fixed thereto by screw-threaded bolts 12. Additional knives 5 of differing thicknesses can be used to allow tunnels of differing diameters to be driven with the same knife shield 1. As an alternative to the fixing of the additional knives 5 using bolts 12, it would be possible to weld the additional knives to the knives 3. CLAIMS

4. A drive shield as claimed in any one of claims 1 to 3, wherein each additional elongate member is connected to the associated elongate member by screw-threaded bolts passing through the internal metal sheet of that additional elongate member.

5. A drive shield as claimed in any one of claims 1 to 3, wherein each additional elongate member is welded to the associated elongate member.

6. A tunnel knife shield substantially as hereinbefore described with reference to, and as illustrated by, the accompanying drawings.