GB1596737A

GB1596737A - Track assemblies

Info

Publication number: GB1596737A
Application number: GB2546378A
Authority: GB
Original assignee: Dobson Park Industries Ltd
Current assignee: Joy Global Industries Ltd
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-08-26
Also published as: FR2427241A1; DE2849535A1; DE2849535B2; DE2849535C3

Description

(54) TRACK ASSEMBLIES (71) We, DOBSON PARK INDUS TRIES LIMITED, a British Company of Dobson Park House, Colwick Industrial Estate, Colwick, Nottingham, NG4 2BX, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: The invention relates to tracked machine and to track assemblies therefor, and is envisaged as being especially applicable to mine machinery where efficient usage of available space is important.

Mine machinery, particularly advancable roof support units, has been proposed for translation by a track-laying assembly or assemblies at least for floor engagement, and possibly also for roof-engagement which would allow advance under roof-loading by the support unit or units. We have, ourselves, also proposed in our copending application no.

25461/78 (Serial No. 1,596,736) a heading machine of this general type where a tracked and thus movable support structure houses a heading machine.

Conventional track-laying assemblies have endless tracks comprising inter articulated sections running in superposed relationship with a "working" run where track sections engage a surface relative to which the machine is supported, or is supporting, and a return run for the track sections. Particularly for mine machinery, this can cause difficulties by way of space and height requirements as there will generally be pressure fluid operated prop or ram means between floorengaging and roof engaging parts of the machine structure. Thus, even multiple telescopic prop or ram means will itself have a minimum height requirement additional to at least that of the groundengaging tracks, it being, of course, possible to mount upper tracks within a span between upper prop or ram engaged side parts of the machine.

It is one object of this invention to provide track type assemblies that are capable of offering loading member support directly on the floor bearing members or working run thereof rather than conventionally via cantilevered constructions where superposed track runs are wholly accessible from one side of a machine such as a construction vehicle, or via means bridging the upper track run say using a box-section construction.

To this end, we propose herein an endless track assembly comprising a plurality of interarticulated track sections forming an endless track and means for guiding the track sections along a "working" run and a return run that are offset one from the other laterally of a direction of desired translation. Such an assembly will allow machine frame part sup port substantially directly by the working run, i.e. past the return run.

Some embodiments of the invention provide that the working and return runs do not even overlap so that supported machine frame parts, and we have specifically in mind hydraulic prop support bases, can be of similar width (at the return run) to the tracks themselves.

With such track assemblies it is preferred that, if they are to be driven rather than freerunning with external traction means, say of haulage or pusher type, drive means is pro vided to engage the track on its working run, say using a pressure fluid operated ram (see for example British patent specification no.

766811) but obviously allowing the use of any other desired drive means such as toothed rotary means.

Track sections may, for the above purposes, be intercoupled by pivots or hinges that allow predetermined extents of relative sliding movement of mating pivoted or hinged parts so that, although axes of articulation from one track section to the next remain parallel and transverse to parallel overall track run directions, succcessive track sections will, in transition between working and return runs, be capable of relative displacement along those axes. Whilst this may be achieved by guide means within the tracked assemblies themselves it is also practical for the guide means to be on the machine frame itself or on parts thereof.

The latter purposes would, of course, be equally well achieved by using track section intercouplings each having a further axis of pivotting, usually perpendicular to the above mentioned pivot or hinge axis, and could be embodied as universal joints or flexible joints, even by a carrier chain. Then, of course, it will normally be necessary to provide for track sections either to be cut-away or chamfered to the or each side of their jointing positions.

Whilst improving requirements as to a minimum machine height such arrangements may have disadvantages by way of increased overall width requirements for track laying or guide assemblies, perhaps especially for a machine or support unit that has side supports only in order to provide fore-and-aft access between those supports.

It is therefore further proposed herein that track assemblies permit or are adapted for their return runs to be rotated or twisted about their overall longitudinal direction so that additional width requirements compared with conventional superposed track runs are reduced to accommodating the thickness rather than the width of track sections This is readily achieved using a flexible track section carrier but can also be implemented by two-axis or universal couplings either medially or, as will be described for a flexible slidable carrier, at one side of the track sections.

Specific embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a vertical view through part of a ground engaging unit of a mine roof support or mining machine using one embodiment of the invention; Figure 2 is a plan view of some track sections of a track assembly of Figure 1; Figure 3 is a diagrammatic representation of an alternative track assembly embodying the invention; Figure 4 is a diagrammatic view shoving the track assembly of Figure 3 in mine machinery; Figure 5 shows details of a preferred track section relevant to Figures 3 and 4; Figure 6 shows diagrammatically how drive may be applied to a track assembly herein; and Figure 7 shows a tracked heading machine in plan.

Referring first to Figures 1 and 2, a tracklaying assembly 10 has successively interarticulated track sections 12 of generally rectangular flat form each having at one end a pivot pin 14 between spaced projecting end portions 16 and at the other end a pivot pin engaging eye 18 of substantially less width than the spacing between end portions 16 and offset to one side of a centre line of the section so that the eyes 18 abut one end portion 16 with the track sections aligned but allow relative displacement of track sections along the pivot axes (see Figure 2). This allows the "working" run 20 of the track to be in the desired position beneath apparatus or machine parts 22 to be moved and the return run 24 of the track to be offset therefrom. As specifically shown, the working run 20 underlies a machine frame foot 26 slidable at 27 on the track sections and slotted at 28 to accommodate and locate relative to lengthwise guides 30 on the inner surfaces of the track sections. The foot 26 carries a hydraulic prop 32 in a housing 34 that may constitute its cylinder, and the return track run 24 is shown positively guided on supporting flanges 36 slotted at 38 and interconnected by a guide channel 40.

It will be appreciated that side guiding surfaces of the guides 30 readily permit translation of successive track sections 12 sideways during transition between working and return runs by engagement with suitable guide means, such as spaced rollers or an extension of guide channel 40, though it is to be noted that close two-sided guidance of the guides 30 is not necessary as loading from translation of the machine will usually tend to pull the return run laterally towards superposition over the working run, especially if the working run is driven, say as shown in Figure 6 by a hydraulic ram 42 operating on slots 44 of the guides 30 via a suitable drive tooth 46 that will normally be adapted for twoway drive and at least for positive engagement in the drive direction and release in the opp site direction by any suitable mechanism, for example a camming arrangement 48 driven in suitable phase with the ram 42.

Whilst Figure 6 shows discrete machine or apparatus supporting feet 26, 26' carrying hydraulic support props it will be appreciated that such feet may be replaced by a single frame member or constitute parts thereof.

Turning now to Figures 3 to 5, Figure 3 shows entirely diagrammatically how a track 50 may comprise sections 52 of trapezoidal shape hingedly or pivotally intercoupled end-toend at or near their long edges 54 by couplings 56 and slidingly engaged at or near their short edges 58 by an endless inextensible member, specifically a chain 60. More details of a suitable track section 52 are given in Figure 5 indicating both long edge pivot bosses 62 and a short edge chain race 64, as well as a guide and drive slot arrangement 30', 44', generally equivalent to that of Figure 2.

Figure 3 appears to demonstrate how successive track sections 52 can pivot about their long edge couplings 56 for a return run with the chain 60 defining the inner periphery or extent of the total run and tapered sides 66, 68 of the track sections will permit accommodation thereto at turning transitions.

However, as will shortly become apparent, Figure 3 is a distorted view presented wholly for the purposes of easy illustration and, in fact, the track 50 is intended to run, see Figure 4, with working and return runs 70, 72 angled and displaced relative to each other.

As shown these are at right angles with horizontal and vertical working and return runs.

The chain length is thus sufficient to accommodate to and define the inner length of such a total track run.

An alternative to the spaced chain and pivotting for trapezoidal track sections, comprises central universal or flexible intercoupi- ing of track sections with ends cut back in plan to each side their centre lines in the direction of translation.

A return track guide after the general conception of Figure 2 is shown at 74 relative to guides 30' only and suitable transition guidance will also be provided as indicated at 76. It will be appreciated, of course, that the chain race may also or alternatively be utilised in the guidance means at least for the return run proper. That may well prove to be particularly satisfactory to cope with any rocking of the track sections during transition between working and return runs by side tapering the guides 30' towards each end, or even making them of half-barrel shape, especially using a continuation of a return track guide channel at the transition. However, the above mentioned spaced roller edge guidance would also solve any such problem as would a guidance channel that is relatively wide overall but has discrete guidance "bumps" or insertions, perhaps preferably at or exceeding the lengths of guides 30'.

An outer shield or guide 78 is also shown for the return run of Figure 4.

Figure 7 illustrates one typical application to a heading machine with spaced ground engaging track units 80, 82 at sides of a support structure 84 also having roof engaging track units 86, 88, not necessarily of the above described type, and housing a percussive type selective mining unit 90 usually, of course, of a type having a manipulable boom after the manner of our above mentioned copending application No. 25461/78 (Serial No.

1,596,736). The structure 84 will have lower parts carried by the ground-engaging units 80, 82 and an upper plart or parts carrying the roof-engaging units 86, 88 with hydraulic props (not shown) acting between them for mine roof support purposes, the whole arrangement allowing advance under prop loading to give permanent roof-support even during translation.

It will be appreciated that a mine roof support unit could be of similar design to the support structure of Figure 7, but will usually be substantially smaller, say with relatively closely spaced ground engaging tracked units with access, if any, at most, for passage of workers and equipment and materials portable thereby, and a single roof engaging tracked unit on a canopy structure either simply superposed over the ground-engaging units and supported directly by extensible and retractable props, or coupled to base or bases for the ground engaging units by a sloping shield articulated to both and itself acted on by a support prop or props as the sole means of roof support or as means additional to props acting directly between base and canopy.

WHAT WE CLAIM IS: 1. An endless track assembly comprising a plurality of interarticulated track sections forming an endless track and means for guiding the track sections along a "working" run and a return run that are offset one from the other laterally of a direction of desired translation.

2. An assembly according to claim 1, wherein the offset substantially equals, or exceeds, the track section width.

3. An assembly according to claim 1 or claim 2, wherein the track sections are interarticulated by pivot or hinge parts permitting relative movement of successive track sections transversely of the direction of desired translation.

4. An assembly according to claim 3, wherein the pivot or hinge parts allow two different axes or freedoms of movement.

5. An assembly according to claim 4, wherein two said axes are at right angles to each other.

6. An assembly according to claim 4, wherein one axis is for rotational movement, and linear movement is also permitted axially of that axis.

7. An assembly according to claim 6, wherein pivot pins and engaging eyes therefor provide for both rotation about the axes of the pivot pins and sliding of each eye along its associated pivot pin.

8. An assembly according to claim 7, wherein eye and pivot pin relations are such that each eye is at one limit of permitted sliding movement when successive track sections are aligned.

9. An assembly according to claim 2, wherein the track sections are interarticulated by universal joints.

10. An assembly according to claim 2, wherein the track sections are interarticulated by flexible means.

11. An assembly according to claim 10, wherein the track sections are further interarticulated by pivots or hinges spaced from the flexible means.

12. An assembly according to claim 9, 10, or 11, wherein successive track sections have adjacent edges configured to permit relative twisting in the plane of surface engaging parts thereof.

13. An assembly according to claim 12, wherein the adjacent edge configuration com

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. for the purposes of easy illustration and, in fact, the track 50 is intended to run, see Figure 4, with working and return runs 70, 72 angled and displaced relative to each other. As shown these are at right angles with horizontal and vertical working and return runs. The chain length is thus sufficient to accommodate to and define the inner length of such a total track run. An alternative to the spaced chain and pivotting for trapezoidal track sections, comprises central universal or flexible intercoupi- ing of track sections with ends cut back in plan to each side their centre lines in the direction of translation. A return track guide after the general conception of Figure 2 is shown at 74 relative to guides 30' only and suitable transition guidance will also be provided as indicated at 76. It will be appreciated, of course, that the chain race may also or alternatively be utilised in the guidance means at least for the return run proper. That may well prove to be particularly satisfactory to cope with any rocking of the track sections during transition between working and return runs by side tapering the guides 30' towards each end, or even making them of half-barrel shape, especially using a continuation of a return track guide channel at the transition. However, the above mentioned spaced roller edge guidance would also solve any such problem as would a guidance channel that is relatively wide overall but has discrete guidance "bumps" or insertions, perhaps preferably at or exceeding the lengths of guides 30'. An outer shield or guide 78 is also shown for the return run of Figure 4. Figure 7 illustrates one typical application to a heading machine with spaced ground engaging track units 80, 82 at sides of a support structure 84 also having roof engaging track units 86, 88, not necessarily of the above described type, and housing a percussive type selective mining unit 90 usually, of course, of a type having a manipulable boom after the manner of our above mentioned copending application No. 25461/78 (Serial No. 1,596,736). The structure 84 will have lower parts carried by the ground-engaging units 80, 82 and an upper plart or parts carrying the roof-engaging units 86, 88 with hydraulic props (not shown) acting between them for mine roof support purposes, the whole arrangement allowing advance under prop loading to give permanent roof-support even during translation. It will be appreciated that a mine roof support unit could be of similar design to the support structure of Figure 7, but will usually be substantially smaller, say with relatively closely spaced ground engaging tracked units with access, if any, at most, for passage of workers and equipment and materials portable thereby, and a single roof engaging tracked unit on a canopy structure either simply superposed over the ground-engaging units and supported directly by extensible and retractable props, or coupled to base or bases for the ground engaging units by a sloping shield articulated to both and itself acted on by a support prop or props as the sole means of roof support or as means additional to props acting directly between base and canopy. WHAT WE CLAIM IS:

1. An endless track assembly comprising a plurality of interarticulated track sections forming an endless track and means for guiding the track sections along a "working" run and a return run that are offset one from the other laterally of a direction of desired translation.

prises tapering in said plane towards at least one edge.

14. An assembly according to claim 13 with claim 11, wherein each track section is of trapezoidal shape in said plane and has said pivots or hinges at or adjacent the longer of its parallel sides and sliding engagement for the flexible means at or adjacent the shorter of its parallel sides.

15. An assembly according to any one of claims 3 to 14, wherein the return run is at an angle to the working run such that the track sections are twisted out of parallelism on those runs and between transitions from one to the other.

16. An assembly according to claim 15 with claim 4, wherein said twisting is to a direction following one of said different axes.

17. An assembly according to any preceding claim, wherein each track section includes guide means on a non-surface engagement part thereof and extending in the direction of desired translation.

18. An assembly according to claim 17, wherein the latter guide means is a projection or projections to mate with channels or recesses of the first mentioned means for guiding.

19. An assembly according to claim 17 or claim 18, wherein the guide means of each track section includes means for receiving a transmitting drive forces in the direction of desired translation.

20. An assembly according to claim 19, with claim 18, wherein in the last mentioned means comprises a tooth engagement indent.

21. An assembly according to claim 19 or claim 20, further comprising drive means.

22. An assembly according to claim 21, wherein the drive means includes a pressurefluid operated ram.

23. An endless track assembly arranged and adapted to operate substantially as herein described with reference to and as shown in Figure 1, or Figures 3 and 5, or Figure 6 of the drawings.

24. A machine incorporating an assembly according to any preceding claim.

25. A machine according to claim 24, wherein support means of the machine is supported substantially directly on the working run of said assembly.

26. A machine according to claim 25, con stituting a self-advancing mine-roof support.

27. A machine according to claim 25, constituting a mine working heading machine.

28. A machine according to claim 26 or claim 27, having at least one said assembly for ground-engagement and at least one endless tracked assembly for roof engagement.

29. A machine according to claim 28, having two spaced said assemblies for groundengagement.

30. A machine according to claim 28 or claim 29, wherein the or each ground engaging track assembly has drive means.

31. A machine according to any one of claims 24 to 30, wherein the guide means comprises parts of the machine.

32. A machine arranged and adapted to operate substantially as herein described with reference to and as shown in Figures 1 and 2 or Figures 3 to 5, or Figure 6 or Figure 7 of the drawings.