GB2198107A - End castings for conveyor line pans - Google Patents

Abstract

An end casting (11, 21) for a conveyor line pan having side sections of sigma shape joined centrally by a deck plate is of substantially constant thickness (16) along its length, i.e. is not reduced in thickness at the end adjacent the next line pan when in use. <IMAGE>

Description

END CASTINGS FOR CONVEYOR LINE PANS This invention relates to end castings for conveyor line pans and to conveyor line pans incorporating such end castings, as employed for armoured flexible conveyors (A.F.C.) AFC's are used in mines, quarries and similar areas for conveying large quantities of particulate material such as rock or coal over distances. In longwall coal mining, the AFC extends along the face Which can be of the order of 250 metres in length. The mining machine traverses reciprocally along and is guided by the pans of the AFC, as it cuts coal from the face, the coal falling onto the pans for conveyance by flight bars which are driven by chains running in races formed in the line pans.

In section, each pan presents a trough like appearance, with side sections, usually of sigma shape connected laterally by a deck plate over Which the flight bars run.

An armoured flexible conveyor canprises a plurality of pans joined serially end to end in an articulated manner to allow limited horizontal and vertical movement. In practice, the pans rarely lie in a straight line, and consequently frictional wear occurs at their ends caused by the chain and the flights. To mitigate this, hardened castings are provided at each end of the line pan. However, it has been found that with the conventional design of such end castings, there is a tendency for more wear to take place than is necessary, and consequentially line pans have to be taken cut of commission thereby occasioning production delays.

It is an object of the present invention to provide an improved form of end casting for a conveyor line pan which gives a longer life than is currently available.

According to the present invention an end casting for a conveyor line pan of the kind having two sigma side sections joined centrally by a deck plate secured between the sections and over which chain driven flight bars are arranged to run is characterised in that the casting has a substantially constant thickness along its length.

The profile of the section of each end casting is preferably similar to the section profile of the sigma side sections.

The end castings are preferably made of a material which is harder than the material of the sigma side sections and are formed as co-operating male and female castings, a line pan normally having a male casting at one end and a female casting at the other.

Each male casting is provided with a projection on the outside of the casting (i.e. the side not subject to the conveyance of material) and this projection is arranged to fit into a corresponding recess on the outside of a female casting.

The female casting preferably presents a continuation of the relatively inside surface of the sigma section to which it is connected and over which the conveyor chain would run with the projection of the male casting registering within the recess. ss. The female casting may have a cut away section under this surface into which a suitably profiled portion of the male projection extends.

The deck plate preferably is welded or otherwise secured to the sigma section and the end castings in one continuous line. The deck plate may be provided at the male end with a stepped portion and at the female end with an undercut portion. The two portions are dimensioned so that one overlaps the other to give support between adjacent decks and a substantially flush surface to the deck over which the flights run. The portions may not ne necessarily be flat but may be slightly angled to allow and assist in articulation of the line pans.

The end castings may be provided on their outsides with suitable connecting means such as bolts or boltless connectors in known manner to secure the adjacent line pans in a fashion allowing limited articulation or movement.

In order that the invention may be fully understood one example of a conveyor line pan having end castings in accordance therewith will now be described with reference to the accompanying drawings.

In the drawings Figures 1 and 2 show an end view and a scrap end part sectional plan, respectively of an existing form of end casting and line pan. Figures 3 and 4 show corresponding views to Figures 1 and 2 of an improved casting in accordance with the invention. Figure 5 shows a plan view of a conveyor line plan section having the castings of the invention and Figure 6 shows a view of the end of the line pan section in the direction of the arrow V. Figure 7 is a perspective view of two end castings showing their manner of interengagement.

Referring now to the drawings and firstly to the prior art cons truct ion shown in Figures 1 and 2 it will be seen that the end casting indicated generally at 1 has a sigma form with a central extension 2 to which a deck plate 3 is welded.

In Figure 2 it can be seen that the end casting 1, which is secured to a side section 4 of the line pan section, is not internally in line with the shape of the section and this is due to the extension 2. The deck plate 3 has to be cut away so as to accanmdate the extension 2 and a weld extends in an irregular form.

The top surface of the sigma section of the end casting 1 is shown at 5 and this is the surface over which the chains and flight bars (not shown) will run. This surface is part of a thin cantilever section 6 which as can be seen clearly from Figure 1, is about half the thickness of a side wall 7 of the section. This cantilever 6 provides a barrier to coal shippage between the upper and lower portions of the sigma section when the conveyor lines pans are articulated. A projection 8 of the male end casting leaves a gap 9 below the section 6 into which a corresponding section of a co-operating female end will be inserted. It will be appreciated fran inspection particularly of Figure 1 that due to the reduced thickness of the cantilever section 6, wear life is much shorter and accordingly the side pan section quickly becanes unusable.

Referring now to Figures 3 and 4 which show corresponding views to Figures 1 and 2 it will be seen that surface 5 is now formed of a section 16 which is virtually the same thickness as the section 7. n-iere is no extension 2 and the deck plate 3 is welded directly to the central area 12 of the hew, female, end casting 11. This means that wear on the surface 5 can be sustained for a much greater length of time than is possible with the prior art type of end casting. From Figure 4 it will be seen that the end of plate 3 is welded in a continuous run between the sigma section 4 and the end casting 11. This straight line weld assists very much in fabrication and means that autanatic welding techniques are more freely available in a construction of the line pans with a consequential increase in reliability and quality.

Under the section 16, a female reception area 17 is formed which can receive a projection 18 formed on a male end casting 21 (Figure 7). The projection 18 has a stepped portion 19 (Figure 6) which fits into a slot 20 below the section 16 of casting 11.

The outside of the sections 11 and 16, i.e. the sides viewed in Figure 7, can be secured together by any known means such as by a bolt passing through the projection 18 on casting 21 and a rib 22 on the end casting 11, or by use of suitable boltless connectors engaging the outside of the castings suitably configured to accept such connectors. It is the inside profiling which is important so that the section 16 is of an adequate thickness.

Referring also to Figure 5 this shows a plan view of a conveyor line section having end castings in accordance with the invention. The end casting shown in Figures 3 and 4 is as viewed in the direction of the arrow W and the end casting shown in Figure 6 is as viewed in the direction of the arrow V. It will be seen that the deck plate 3 of Figure 5 is provided with a step at 30 adjacent the male end castings and with an undercut 31 adjacent the female end castings. The dimensions of the step and the undercut are such that when adjacent pans are joined together in end to end relationship the step and the undercut mate to present an effective continuous top surface.The top of the section and the undercut are each inclined slightly to the horizontal as can be seen particularly in Figure 6 so that the articulation between deck plates as movement occurs of adjacent line pan sections is assisted. There is also a slight chamfering between the surface of the deck plate as indicated at 32 and 33.

It will be appreciated that use of end castings in accordance with the present invention enables line pan sections and conveyors to be constructed in the absence of the weak spots characteristic of conventional line pan sections. The novel end castings give a smooth, continuous surface and reduce the amount of wear at the joints between line pan sections.

Articulation of the line pans having end castings in accordance with the invention does not cause coal shippage between upper and lower races of the sigma sections. Furthermore due to the fact that a continuous weld can be formed along the length of the deck plate with the side pan sections and the end castings, manufacture is expedited and a higher quality is obtained.

Claims (12)

CLAIMS :

1. An end casting for a conveyor line pan of the kind having two sigma side sections joined centrally by a deck plate secured between the sections and over which chain driven flight bars are arranged to run characterised in that the casting has a substantially constant thickness along its length.

2. An end casting according to claim 1 having a sigma section profile corresponding to that of the side sections.

3. An end casting according to claim 1 or 2 in which the material fran which the end casting is made is harder than that of the side sections.

4. An end casting according to any one of the preceding claims in which the end casting is female and is provided with an external recess having a substantially constant wall thickness.

5. An end casting according to claim 4 in which the recess is relieved to provide a slot opening into the inside of the casting at its centre.

6. An end casting according to claims 4 and 5 in which the end casting is male and is provided with a projection for engagement with the recess of the female end casting.

7. An end casting according to claim 6 in which the projection of the end casting is provided with a step engageable with the slot of the female end casting.

8. An end casting substantially as hereinbefore described with reference to Figures 3 to 7 of the accompanying drawings

9. A line pan comprising two sigma side sections joined centrally by a deck plate secured between the sections, and an end casting in accordance with any one of the preceding claims provided at each end of each sigma side section.

10. A line pan according to claim 9 in which female end castings are provided at one end of the pan and male end castings are provided at the other end thereof.

11. A line pan according to claim 10 in which the deck plate adjacent the end of the line pan having male end castings is stepped, and the deck plate adjacent the other end of the line pan is undercut.

12. A line pan substantially as hereinbefore described with reference to Figures 3 to 7 of the accompanying drawings.