GB2197838A

GB2197838A - Access door for conveyor line pans

Info

Publication number: GB2197838A
Application number: GB08727206A
Authority: GB
Inventors: David Glyn Thomas; Gareth Roberts
Original assignee: Coal Industry Patents Ltd
Current assignee: Coal Industry Patents Ltd
Priority date: 1986-12-02
Filing date: 1987-11-20
Publication date: 1988-06-02
Also published as: GB8727206D0

Abstract

A conveyor line pan has first and second sigma side sections (1,2) interconnected centrally by a deck plate which is provided with a cut-out access area (7) extending the full width between the sections (1,2). An access door (15) sits on ledges (8) formed on the bounding edges of the deck plate and is held in place by a securable casting (11) having an internal profile matching that of the side section (1). <IMAGE>

Description

ACCESS DOOR FOR CONVEYOR LINE PANS This invention relates to line pans for conveyors and is particularly concerned with the provision of access doors in the deck plates of such line pans.

In coal and other mines, material is conveyed on armoured face conveyors whidh are canprised of a series of conveyor line pans joined end to end in an articulated manner. Eadh pan basically canprises two sigma side sections which are centrally joined by a horizontal deck plate. Chains run in races formed in the side sections of the line pans and draw bar flight bars over the deck plate to convey particulate material there along. The chains and the flight bars form a continuous band and run the length of a conveyor over drive sprocket arrangements at the ends and back under the deck plate.

It is often necessary for maintenance and fault correction purposes to gain access to the conveyor chain and flight bars beneath the deck plate in the return run. To this end, it is usual for about every sixth pan to have incorporated in the deck plate an access door whidh can be removed wnen the conveyor is stopped to allow the requisite access.

In order not to interfere with the smooth flow of the conveyor chain and flight bars the access doors have to be fitted flush with the upper most surface of the deck plate of the conveyor. To date this has been achieved by cutting a hole in the deck plate and machining an area out of the deck plate at the edges of the hole onto which the access door can be laid. The access door is provided with recessed latch keys which can be slid horizontally to engage with staples welded to the under side of the deck so as to hold the deck in position.

This type of access door suffers from the disadvantage that it is liable to wear particularly at the points where the latch keys are fitted and furthermore the latch key areas very easily fill with dirt and became jammed and difficult to operate.

It is an object of the present invention to provide an improved form of access door for a conveyor line pan which does not rely on retaining keys and which is simple and easy to use.

It is a further object to provide such a form of access door suitable for use on heavy duty conveyors which are designed to carry large amounts of material and which have a substantial depth in the sigma side sections.

According to the present invention a conveyor line pan of the kind having two sigma side sections joined by a horizontal deck plate welded to the central portions of the sigma sections includes in or adjacent the centre of the deck plate an access area extending the full width between the side sections, the edges of the deck plate adjacent this area being stepped to provide ledges upon which an access door may rest, the sigma section on one side of the conveyor being provided with a cut away portion adjacent the access area to provide a longitudinally extending lip upon which the edge of the access door can rest and having retaining means for securing the door to the sigma section, the door spanning the width of the access area and extending to the second sigma section in order completely to close the area.

The second sigma section is preferably undercut adjacent the access area and the door is provided with an underlip which fits into the undercut of the second sigma section.

Preferably the access door is stepped at its sides to correspond with the stepping of the deck plate and to enable the top surface of the deck plate to present a smooth uninterrupted surface with the surface of the door. The door itself is preferably the same thickness as the deck plate so as not to give any weakening in the deck plate.

The retaining means is preferably a casting securable by for example bolting to the first sigma section. The casting preferably follows the profile of the inner side of the sigma section and is provided with a recess to enable it to overlap the end of the access door and to clamp it in position.

The door may be provided with a cut out section to enable it to be moved initially fran the closed position when the retaining means is released. This cut out is conveniently located adjacent to the second sigma section.

In order that the invention may be readily understood one example of a conveyor line pan having an access door in accordance with the present invention will now be described with reference to the three figures of the accompanying drawing. In the drawing Figure 1 shows a plan view of a line pan having an access door, Figure 2 shows a cross section through the pan on the line AA of Figure 1 and Figure 3 is a side view of the central part of the pan showing the retaining means.

Referring now to the drawings it is assumed that the pan of the present invention is part of a series of pans in an armoured face conveyor for use on a coal mine face. The line pan canprises a first sigma section 1 which is located on the face side of the installation of which the conveyor forms part and a second sigma section 2 which is located on the goaf side. The sections 1 and 2 are of cast steel and are joined by a base deck plate 3 welded between their lower projections.

A deck plate 4 is welded between the central sections of the sigma sections 1,-2 and the deck plate 4 is made up of two parts namely a female deck plate 5 and a male deck plate 6.

The male and female references are to the ends of the deck plate which contact adjacent line pans in accordance with our copending application 86 28738 (Case 4868). Between the two deck plates 5 and 6 is an area 7 for allowing operators to gain access to the region beneath the deck plate 4 for maintenance purposes. The edges of the plates 5 and 6 bounding the access area 7 are stepped for half of their thickness to provide ledges 8.

The sigma section 1 is relieved in its top central portion adjacent the access area 7 as shown at 10. A retaining member 11 of stepped cross section as is shown in Figure 2 is secured to the sigma section by bolts 12.

The second sigma section 2 in its central section adjacent the access area is provided with an undercut recess 14 so that the sectional depth of the central portion of the sigma section is about half the thickness of the deck plate in this area.

As can be seen particularly from Figures 1 and 2 an access door 15 is provided which fits over the access area 7.

The access door 15 has stepped side parts which complement and rest on the ledges 8 such that the door 15 and the deck plate 4 are flush. The door 15 is of a material which is the same hardness and thickness as the deck plate 4.

Adjacent the second sigma section 2 the edge of the door 15 is lipped as at 16 (Figure 2) to engage the recess 14 of the central part of the sigma section to enable the access door 15 to fit flush against the central part of the sigma section 2.

The central section of the side section 1 in the area of the relief 10 provides a support surface 17 upon which one end of the access door rests. With the access door in the position shown in full lines the retaining member 11 can be positioned over it and secured in position by bolts 12 to hold the door securely in position against movement.

The door 15 is provided with a cut out portion 18 adjacent the second section 2 to assist with removal of the door, as will be explained.

Under normal running conditions the door is secured into the line pan conveyor as shown in full lines in the drawings.

If it is necessary to inspect below the deck plate 4, the conveyor is stopped, and the door 15 removed by first undoing the two bolts 12 and withdrawing the retaining member 11. By inserting a suitable implement in the cut out 18 the door 15 can be levered towards the face side i.e. towards the side section 1 until the edge of the door is free of the second section and the lip 16 can be disengaged. The lip is now pulled upwards and the door can be swung up above the conveyor and lifted out as indicated by the dotted position 20. When it is required to replace the door it is repositioned into the position 20 and then lowered onto the deck plate parts 5 and 6 to rest on the ledges 8 and pushed towards the second section 2 until the lip 16 engages in the recess 14 and the deck abuts the section 2.The retaining member 11 is now replaced to capture the end of the deck plate on the surface 17, and is secured in position by reinserting the bolts 12.

It will be seen that the invention enables the deck plate swiftly and easily to be removed within the width of the conveyor and d does s not rely on fixing or retaining means which are in the direct line of flow of the conveyor and thus iiable to wear. Furthermore the deck plate does not need to be slid through the width of the conveyor on to the face side of the line pan which would necessitate men working on a very dangerous part of the face.

Since the access door 15 is the same thickness as the deck plate 4, there is no weak spot in the deck plate and the door is fully supported by the ledges 8.

Although bolts have been shown to secure the retaining member 11 in position it is possible to use alternate ways of securement such as by pins or known forms of boltless connector.

Claims

MAIMS.

1. A conveyor line pan of the kind having two sigma side sections joined by a longitudinal deck plate welded to the central portion of the sigma section, the line pan including in or adjacent the centre of the deck plate an access area extending the full width between the side sections, the edges of the deck plate adjacent this area being stepped to provide ledges upon which an access door may rest, the sigma section on one side of the conveyor being provided with a cut away portion adjacent the access area to provide a longitudinally extending lip upon which the edge of the access door can rest and having retaining means for securing the door to the sigma section, the door spanning the width of the access area and extending to the second sigma section in order completely to close the area.

2. A conveyor line pan according to claim 1 in which the second sigma section is undercut adjacent the access area and the door is provided with an underlip which fits into the undercut of the second sigma section.

3. A conveyor line pan according to claim 1 or 2 in which the access door is stepped at its sides to correspond with the stepping of the deck plate.

4. A conveyor line pan according to any one of the preceding claims in which the access door is of the same thickness as that of the deck plate.

5. A conveyor line pan according to any one of the preceding claims in which the retaining means is a casting securable to the first sigma section.

6. A conveyor line pan according to claim 5 in which the casting follows the profile of the inner side of the sigma section and is provided with a recess to overlap the end of the access door and to clamp the same.

7. A conveyor line pan according to any one of the preceding claims in which the access door is provided with a cut-out section adjacent the second sigma section.

8. A conveyor line pan substantially as hereinbefore described with reference to the accompanying drawings.