GB2069435A - Underground suspended railway structure - Google Patents

Abstract

Monorail track (1) comprises running rails arranged end-to-end and suspended at their ends by chains (2) which are connected to beams (12). The beams (12) extend between girders (10 and 11). Devices (19 and 28) for supporting respective end portions of the beam include stirrups, one of which is slidably mounted on the beam so that relative movement of the girders is allowed for. The position of attachment of the chain (2) to the beam (12) is selected so that the chain may hang substantially vertically. <IMAGE>

Description

SPECIFICATION Improvements relating to underground suspended railway structures This invention relates to a suspended railway structure in a mine or other underground working.

Railway tracks in underground mine workings are commonly suspended from roof-supporting girders by means of chains. One end of each chain is connected by a suitable bracket to a girder and the track is attached to the chain at a position along the length of the chain which is selected according to the required height of the track relative to the girder. The track comprises a number of rails arranged end-to-end. Because movements of the girders are likely to occur during the service life of the railway structure, it is desirable to connect the rails together in a manner such that some degree of free articulation of adjacent rails in a vertical plane can occur. For this reason, it is desirable to suspend each rail by its ends only, otherwise the connected ends of adjacent rails may move vertically when a load passes along the track.

It is not always convenient to so arrange a track that the ends of each rail coincide with roofsupporting girders. Accordingly, it is common for some of these suspension chains to be inclined in a direction along the track. A tension in the chain resulting from a given vertical load increases as the inclination of the chain to the vertical is increased. Thus, inclined chains may be stressed excessively or chains having a greater strength than would be required if the chains were always arranged vertically must be used. Furthermore, the inclined suspension chains apply to the roof supporting arches forces having a component in a horizontal direction along the track. Such forces tend to displace the arches from their required positions.Also, the inclination af some of the chains makes it difficult to install the track with the rails level or uniformly inclined.

It is an object of the present invention to provide a suspended railway structure in which the significant inclination of suspension chains can be avoided.

According to the invention, there is provided an underground suspended railway structure including a track comprising a plurality of running rails arranged end-to-end and a plurality of roofsupporting girders which are spaced apart along the track and from which the track is suspended, wherein the adjacent ends of a pair of running rails are suspended from a beam and a supporting means supports the beam from selected ones of the girders, the supporting means including a device engaged with an end portion of the beam and with a corresponding girder, said device being arranged to support said end portion in alternative positions with respect to the corresponding girder and thereby providing for adjustment of said end portion relative to the girder in a direction longitudinally of the beam.

By selecting the position along the beam from which the ends of the running rails are suspended so that this position lies directly above the ends of the rails, inclination of a chain or other element by which the rails are suspended can be avoided.

Furthermore, the beam may be supported between girders a variety of distances apart by selecting an appropriate position of the end portion relative to the girder engaged by the device.

Furthermore, if said device is arranged to permit limited movement of the end portion relative to the girder, limited relative movement of the girders from which the beam is supported can be accommodated even when an opposite end portion of the beam is fixed to a corresponding one of the girders.

In one preferred embodiment the beam is formed with a series of apertures which are spaced apart along the beam and a bracket is fastened to the beam at a selected position along the length of the beam by means of a releasable fastener which extends through a selected one of the apertures.

In an alternative preferred embodiment, the beam is of a generally channel-shaped crosssection with the two limbs thereof directed generally downwardly when the beam is in use, and the beam is formed with a series of corresponding pairs of apertures which are spaced apart along the beam so that a closed loop may be fastened to the beam at a selected position along the length of the beam by means of a releasable fastener which extends through a selected pair of the apertures.

The device may include a stirrup through which the beam can slide.

The invention will now be described, by way of example, with reference to the accompanying drawings wherein: FIGURE 1 illustrates diagrammatically a part of a suspended railway structure; FIGURE 2 shows on an enlarged scale a beam and adjacent parts of the structure of Figure 1; FIGURE 3 shows a cross-section on the line Ill-Ill of Figure 2; and FIGURE 4 shows a cross-section on the line IV-lV of Figure 2.

The underground suspended railway structure shown in the accompanying drawing includes a monorail track 1 comprising a plurality of running rails arranged end-to-end. The rails are suspended at their ends by chains 2 which are connected to the rails by brackets 3. The structure further comprises a series of roof-supporting girders which are spaced apart along the track. The girders may be arch girders or rectilinear girders supported by props. Where the ends of running rails of the track lie directly below a girder or approximately directly below a girder, the chains by which the ends of the rails are suspended are attached to the corresponding girder by brackets which may be of known construction.

In the drawing there is shown a cross-section of each of two adjacent roof-supporting girders 10 and 11, between which the adjacent ends of a pair of running rails 4 and 5 are disposed. The ends of these rails cannot be suspended directly from one or other of the arches 10 and 11 by means of a substantially vertical chain.

Between the arches 10 and 11, there extends a beam 12 in which are formed a series of apertures 14 which are spaced apart along the length of the beam. A bracket 1 5 is releasably connected to the beam by a bolt 16 which extends through a selected one of the apertures 14. The bracket includes an eye 17 situated below the beam to enable the suspension chain 2 to be attached to the bracket by means of a bolt 1 8. If the bolt 1 6 is withdrawn from the aperture 14, the bracket can be moved along the beam to a selected other one of the apertures 14 and then be fastened to the beam at that position by means of the bolt. The beam 12 lies directly above and is parallel .to the monorail track 1 so that the bracket 1 5 can be positioned substantially directly above the adjacent ends of the pair of running rails 4 and 5.

The ends of these rails can be suspended from the bracket by means of a substantially vertical chain.

The beam 12 shown in the drawings is of a T-shaped cross-section along a substantial part of the length of the beam. Various designs of beams may be used for spanning the gap between pairs of girders. In one alternative embodiment (not shown in the drawings) the beam forms a channel-shaped cross-section, with the two limbs thereof directed generally downwardly when the beam is in use. This embodiment does not necessitate use of a bracket such as the bracket 15 in combination with the chain 2 and the beam.

A link of the chain, or some other closed loop attached to the chain, may be inserted between the limbs of the channel-shaped beam is so that a bolt may be passed through an aperture in one limb of the beam, the loop, and a corresponding aperture in the other limb of the beam. One of a plurality of pairs of corresponding apertures in the channel-shaped beam may be selected for use, in a like manner as for beam 12.

Devices 19 and 28 are arranged to support respective end portions of the beam 12 from girders 10 and 11. The device 19 arranged to support one end portion from the girder 11 comprises a stirrup 21 slidably mounted on the beam 12. A fixed end stop 30 prevents the beam from sliding out of the stirrup. In an alternative arrangement the end stop may have a removable bolt.

The stirrup 21 is suspended from opposed jaw pieces 26 by means of a bolt 24. A further bolt 25 is used to bring the opposed jaw pieces 26 into pressure contact with the flange 18 of the girder 11. The bolts 22, 24 and 25 extend through slightly elongated apertures in the stirrup and jaw pieces so that a degree of rocking of the device is allowed for.

Device 28, identical to device 19, supports the other end of the beam from the girder 10, there being a single aperture 29. Alternatively the device 28 may be permanently secured to the beam, such as by welding. The weight of the beam is taken up by the stirrups of devices 19 and 28. A beam thus supported transmits a downward load of the track to the roof-supporting girders. The stirrup 21, through which a portion of beam between the end stop 30 and the apertures 14 may slide, enables the beam to be fitted between girders a variety of distances apart. The beam will adjust to relative movement of the girders. The design of stirrup 21 is adapted to suit the crosssectional shape of the beam 12.Stirrups used with beams of different cross-section may be of a correspondingly different design for accommodating the beam, so that the beam will adjust to relative movement of the girders in the same manner as does beam 12.

As compared with arranging the track so that the ends of each rail lie directly below respective girders, it is relatively easy to arrange a track so that the ends of each rail do not lie directly below roof-supporting girders but lie directly below beams such as the beam 12. If a track is arranged in this manner, the load which is transmitted from the track by each chain to the roof-supporting girders is distributed between two such girders.

Since the load which can be supported by the track is limited by the maximum load which can safely be applied to any one girder, this arrangement increases the load capacity of the railway structure. It will be noted that none of the apertures 14 is situated immediately adjacent to either of the arch girders 1 0 and 11. This ensures that the load applied to either arch is substantially less than the tension in the chain 2.

Claims (6)

1. An underground suspended railway structure including a track comprising a plurality of running rails arranged end-to-end and a plurality of roofsupporting girders which are spaced apart along the track and from which the track is suspended, wherein the adjacent ends of a pair of running rails are suspended from a beam and a supporting means supports the beam from selected ones of the girders, the supporting means including a device engaged with an end portion of the beam and with a corresponding girder, said device being arranged to support said end portion in alternative positions with respect to the corresponding girder and thereby providing for adjustment of said end portion relative to the girder in a direction longitudinally of the beam.

2. An underground suspended railway structure according to claim 1 wherein the beam is formed with a series of apertures which are spaced apart along the beam and a bracket is fastened to the beam at a selected position along the length of the beam by means of a releasable fastener which extends through a selected one of the apertures.

3. An underground suspended railway structure according to claim 1 wherein the beam comprises a generally channel-shaped cross-section with the two limbs thereof directed generally downwardly when the beam is in use, and the beam is formed with a series of corresponding pairs of apertures which are spaced apart along the beam so that a closed loop may be fastened to the beam at a selected position along the length of the beam by means of a releasable fastener which extends through a selected pair of the apertures.

4. An underground suspended railway structure according to any preceding claim wherein the device includes a stirrup through which the beam can slide.

5. An underground suspended railway structure substantially as herein described with reference to and as shown in the accompanying drawings.

6. Any novel feature or novel combination of features herein described.