GB2099385A - Underground suspended railway structures - Google Patents

Abstract

A beam (12) is supported between a pair of arches (10, 11) and adjacent ends of a pair of running rails (4,5) are suspended from the beam. One end portion of the beam rests in a stirrup (27) welded to the beam and suspended from one of the arches. The opposite end portion of the beam rests in a stirrup (20) through which the beam can move during assembly. After assembly, a grub screw (28) in the stirrup is tightened onto the beam to prevent subsequent movement. <IMAGE>

Description

SPECIFICATION Improvements relating to underground suspended railway structures Description of Invention 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-toend. 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 girders forces having a component in a horizontal direction along the track. Such forces tend to dispace the girders from their required positions. This problem is exacerbated by the forces applied to the track rails by locomotives or trains when these are accelerating or decelerating.

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, said device including settable means which can be set in a condition in which it impedes longitudinal movement of the beam relative to the device, the settable means initially being in a condition in which it does not significantly impede longitudinal movement of the beam relative to the device, and said device being adapted to transmit between the beam and said corresponding girder force acting in a direction along the beam.

The supporting means can further include a support which provides a rigid connection between a further end of the beam and a further girder. The beam can be supported between girders which are spaced various distances apart by selecting an appropriate position relative to the girder engaged by said device of the end portion engaged by the device. Whilst the settable means provides for adjustment of the beam relative to one girder during assembly of the beam with the girders, once the settable means has been set in the condition in which it impedes longitudinal movement of the beam, longitudinal movement of the beam relative to either girder is impeded and any force having a component acting in a direction along the track which is transmitted from the track to the beam is applied to both of the girders associated with the beam.

An example of a railways structure embodying the invention will now be described, with reference to the accompanying drawing wherein Figure 1 shows diagrammatically a part of a suspended railway structure; and Figure 2 shows certain parts of the structure shown in Figure 1 as viewed in the direction of the arrow II in Figure 1.

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 girders 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.

An upper link 15 of the chain 2 is releasably connected to the beam by a bolt 16 which extends through a selected one of the apertures 14. If the bolt 16 is withdrawn from its aperture, the chain 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 chain 15 can be substantially vertical. The beam 12 has the form of an inverted channel so that the link 15 can be received between downwardly projecting limbs of the channel.

Support devices 18 and 19 are arranged for supporting respective end portions of the beam 12 from the girders 10 and 11. The device 19 associated with the girder 11 comprises a stirrup 20 within which the beam is a free sliding fit. An end stop 21 fixed on the beam (but not shown in Figure 2) prevents the beam sliding completely out of the stirrup.

The device 19 further comprises a pair of opposed jaws 22 and 23 which grip between them a lower flange of the girder 11. The jaws 22 and 23 are clamped onto the girder by a bolt 24 which also connects the stirrup with the jaws. The bolt extends through aligned apertures in the stirrup and in the jaws with sufficient clearance to permit limited pivoting of the stirrup 20 relative to the girder 11 about a horizontal axis which extends laterally of the beam 12. Such pivoting brings abutment surfaces 25 and 26 of the stirrup respectively into pressure contact with downwardly facing and upwardlyfac- ing surfaces of the beam 12.

The device 18 also comprises a stirrup 27 for receiving the beam and may be identical with the device 19. The stirrup 27 is preferably rigidly secured to an adjacent end portion of the beam, for example by welding.

During assembly of the beam 12 with the devices 18 and 19 and the girders 10 and 11, the stirrup 20 can be moved along the beam, provided the stirrup is maintained at right angles to a longitudinal axis of the beam. When the components of the assembly have been established in their required relative positions, friction between the stirrup 20 and the beam is increased to impeded sliding of the beam through the stirrup. To this end, there is provided in the device 19 settable means in the form of a pair of screws 28 and 29 which engage in respective scre-threaded bores formed in opposite limbs of the stirrup, the screws being co-axial and the axis of the screws intersecting the beam 12 near to the upper boundary thereof. The screws 28 and 29 are driven towards each other through the stirrup to engage the beam 12 tightly.This engagement impedes longitudinal movement of the beam relative to the stirrup 20 sufficiently to ensure that any tendency for the beam to move longitudinally relative to the girder 11 causes pivoting of the stirrup relative to the girder, rather than sliding of the beam through the stirrup.

As hereinbefore mentioned, such pivoting brings the abutment surfaces 25 and 26 into pressure contact with the beam so that the beam is then gripped tightly by the stirrup. The greater the longitudinal movement of the beam relative to the girder 11, the more tightly is the beam gripped by the stirrup.

It will be seen that the device 19 is adapted to transmit from the beam 12 to the girder 11 forces acting in a direction along the beam, by virtue of the provision of the abutment surfaces 25 and 26, of the limited freedom for pivoting of the stirrup relative to the girder and by virtue of the fact that the stirrup is trapped between the jaws 22 and 23 on the bolt 24. It will be understood that the device 18 also is adapted to transmit between the beam and the girder 10 forces acting in a direction along the beam. Accordingly, whenever the rails 4 and 5 of the track are subjected by a locomotive or train to forces having a component acting in a direction along the track, such forces are transmitted by the chain 2, beam 12 and devices 18 and 19 to the girders 10 and 11 so that these girders together resist longitudinal movement of the track. The girders also support together the downward load transmitted to the beam 12 from the track.

It will be understood that the beam 12 and devices 18 and 19 also prevent relative movement of the girders 10 and 11 in a direction along the beam A beam having a cross-sectional shape other than that illustrated in the drawing may be used, the shape of the stirrups 20 and 27 being modified accordingly.

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, said device including settable means which can be set in a condition in which it impedes longitudinal movement of the beam relative to the device, the settable means initially being in a condition in which it does not significantly impede longitudinal movement of the beam relative to the device, and said device being adapted to transmit between the beam and said corresponding girder force acting in a direction along the beam.

2. A structure according to Claim 1 wherein said device is adapted by the provision of respective abutments between which the beam is received and which are engageabie one with an upwardly facing surface and the other with a downwardly facing surface of the beam, and by a provision for pivotal movement of said abutments together relative to the corresponding girder about a laterally extending axis transverse to the length of the beam.

3. A structure according to Claim 2 wherein said device comprises a pair of jaws, a stirrup which includes said abutments and a pain which extends through respective apertures in the jaws and the stirrup with sufficient clearance to permit said pivotal movement of the stirrup to occur relative to the jaws.

4. Astructure according to any preceding claim wherein the settable means comprises a screw which is driven into engagement with a lateral face ofthe beam.

5. An underground railway structure substantially as herein described with reference to and as illustrated in the accompanying drawing.

6. Any novel feature or novel combination of features disclosed herein or in the accompanying drawing.