WO2002083527A1

WO2002083527A1 - Conveyor belts

Info

Publication number: WO2002083527A1
Application number: PCT/GB2002/001669
Authority: WO
Inventors: Gregory Quy Hall
Original assignee: FOULDS Ltd
Current assignee: FOULDS Ltd
Priority date: 2001-04-12
Filing date: 2002-04-12
Publication date: 2002-10-24
Anticipated expiration: 2003-10-12

Abstract

Conveyor belt with edging comprising a bead part (13) engaging the belt (10) only locally of the edge (12) of the belt and having mutual mechanical interference fit (16/17) adjacent said belt edge (12). Typically, the edging extends inboard of the belt by less than 2.5% of the belt width and is of or for the longest and outermost edge of a corner or curve conveyor to serve for at least support, guiding or location purposes.

Description

TITLE: EDGED CONVEYOR BELT

DESCRIPTION

FIELD OF INVENTION

This invention relates to conveyor belts and has particular reference to application of enlarged edging.

BACKGROUND TO INVENTION

This invention has arisen particularly from consideration of so-called "corner conveyors" where a conveyor belt is required to traverse a curve or bend in a plane of conveyance. European patent specification 0349830 relates to such a conveyor, specifically to provision of a bead at the outer edge of its conveyor belt to present an enlargement to be engaged by inclined guide wheels or rollers serving accurately and securely to locate the conveyor belt through the curve or bend of the corner conveyor, as known earlier. The main teaching is for the edge bead to extend substantially over the width of the belt, i.e. substantially past the engagement positions of the guide wheels or rollers. Whilst such prior provisions can facilitate securement of the bead to the belt by bonding where of suitable material for such bonding, the bead extension from the edge of the belt can be a less than welcome intrusion onto the conveying surface of the belt, and readily bondable bead materials tend not to have good wear properties . SUMMARY OF INVENTION

It is an object of this invention to mitigate such disadvantageous bead extension and/or wear features .

According to one aspect of this invention, there is provided edging for a conveyor belt, the edging comprising a bead part to engage the belt only locally of an edge of the belt, the bead part and part of the belt adjacent it said edge having mutual location provisions for interengagement to fix the bead part at the edge of the belt. Such interengagement can involve mutual mechanical interference inter-fitting.

A suitable bead part has a slot to receive the edge of the belt and an into-slot rib or tooth provision to engage in a groove in the belt inboard of but close to that edge. The into-slot rib or tooth will advantageously be at the mouth of the slot or at least closer thereto than to the blind root of the slot. Termination of the bead can be at the rib or tooth or within a few millimetres thereof, and may extend no more than 10 to 20 millimetres over the edge of the belt, say 12 millimetres or less for a belt-groove centred at 10 millimetres or less inboard of the edge of the belt. Such a bead part is readily extruded from wear- resistant material such as polyurethane of suitable hardness. Prototype testing has shown such a bead part of about 16 millimetres diameter to be satisfactory, so that more than 20 millimetres diameter or otherwise extent in the plane of the belt is unlikely to be needed for the required efficacy. Moreover, even if a small overhang is provided for beyond the actual mechanical interference fit, say to position engagement by guide or locating or support and/or drive rollers, immediately beyond or directly over such interference fit, the slot extent or from the belt edge need not be more than about 15 millimetres, usually about 10 to 12 millimetres, which would not exceed about 2.5% of the width of even the narrowest of likely practical belts, say about 600 millimetres, and can be much less, say 1.5% or less for most typical belt widths of 1 metre, feasibly much more, say at least 3 metres or so. For typical bead parts optimised for maximal efficacy, say with mechanical interference fit at mouths of their belt edge receiving slots, such figures apply to both of the mechanical inter-fit and the bead part both overall and as to its slotting. An alternative composite structure could be a bead part with a belt edge receiving slot and an in-slot groove formation to receive a fixing strip also engaging in a groove in the belt close to but inboard of that edge. Such bead part and strip are each readily extruded from suitable materials.

Such grooving of the belt can be such as not to intrude into typical reinforcement of the belt, i.e. limited to be within depth of outer surfacing of the belt, say within wear surfacing, and typically of not more than 1 millimetre slot depth.

Practical bead parts can serve in guiding and/or supporting actions, conveniently engaged by inclined wheels or rollers that will tend to close the slot of the bead and clench the bead to the belt, and/or as drive rails, conveniently for driving the belt through said guides .

Assembly and fixing can make use of dry and preferably untacky intermediate layers of fusible or weldable material between the interfitting surfaces of the bead part and the belt, and activated after assembly. BRIEF DESCRIPTION OF DRAWINGS

Exemplary specific implementation for this invention will now be shown and described with reference to the accompanying diagrammatic drawing, in which: Figures 1A - ID show components and stages of preparation and assembly of belt edge beading;

Figure 2 shows fixing using an intermediate layer, strip or film 21;

Figure 3 is an exploded scrap section through a conveyor belt 30 showing its edge 32 for fitting with beading 33 ; and

Figure 4 is an exploded scrap section showing belt edge 42 and beading 43 with an intermediate fixing strip 48.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS

In Figures 1A -D, a conveyor belt 10 is indicated as being of composite structure, typically laminations of synthetic plastics material such as polyurethane (PU) or polyvinylchloride (PVC) and textile fabric reinforcing and base materials, further typically about 3 millimetre overall thickness. The beading 13 is shown as a bead part slotted at 15 to fit over the edge 12 of the belt 10. The slot 15 of the bead part 13 is shown with a rib or tooth 16 at its mouth to fit into and inter-engage with a groove 17 in the belt 10 inboard of but close to the edge 12.

The groove 17 can be formed by a heated horse-shoe blade 17B specifically configured to match the desired profile of the groove 17, preferably to some extent tapered inwardly of its depth. The blade 17B may travel along the belt 10, but most likely relative movement is of the belt 10 through a blade heating station.

The conveyor belt 10 with an enlarged edge bead 13 is particularly useful and advantageous where to be engaged for any purpose, see inclined upper and lower wheels or rollers 39A, B in Figure 3, and inclined engaging surfaces 34A, B for belt edge guiding support and/or location purposes appropriate to corner or curve conveyors .

Such engagement will, of course, tend to close the slot and clench the bead part onto the belt locally about its edge, including aid mutual gripping of mechanical inter-engagement of illustrated in-slot beading rib and belt grooving.

The internally toothed slotted bead 13 can be fed onto the belt edge with the rib or tooth 16 in register with the groove 17 and with little or no spreading of the mouth of the slot 15. However, it is envisaged that such spreading will usually be practical, followed by closure of the slot by elastic recovery and/or applied clenching force. Assurance of fixing can be by adhesive 11, say wet bonding agent applied to either or both interfitting surfaces of the bead part and the belt edge and cured or allowed to cure after assembly, and/or by other or additional fusing or welding using solvent or heat, or mechanical assistance may be used through the beading.

Loading of the bead part slot 15 with adhesive, typically solvent-based adhesive, is indicated in Figure IB, see applicator means 15G with jet or spray head 15H. The bead part 13 can, with advantage, be of a material compatible with the belt 10, say of the same or compatible plastics as used in the belt 10, at least where to be fused about the belt edge 12. Typical materials combinations include PVC for the grooved belt layer 10G and PU for the extruded bead part 13, though they could both be of PU; and solvent-based PU adhesive.

Solvent-based adhesives may require the belt with the attached bead part to be left for up to 24 hours or more. Figure 2 shows alternative fixing of the bead part 23 to the belt 20 using a strip or film 21 applied about the edge of the belt 20 including into the groove 27. At least in principle, double-sided adhesive tape form of strip or film 21 may be used. In practice, an initially dry and preferably untacky but heat-fusible layer 31 may be preferred, say heat-meltable polyurethane strip or film. An alternative could by way of fusible or weldable material that is otherwise activated, say ultrasonically. Dryness and untackiness at interfitting is preferred, but that does not rule out application by coating-on or dipping or spraying-on wet and allowing to dry before assembly.

An alternative effectively mechanical keying of a bead part and the belt near its edge could be by way of an edge-adjacent rib or tooth formation on the belt and a complementary groove in the slot of the bead part.

Figure 4 shows a further alternative in which both of the belt 40 and a flank of the slot 45 in the bead 43 are grooved at 47 and 46 so as to take a strip 48 that keys in both of the grooves 46, 47 and could be installed in either first if and as desired.

As applied to embodiments using a keying strip as at 48 in Figure 4, intermediate bond-assisting layers or strips or films (as 21 in Figure 2) can also go over or otherwise go over the keying strip, perhaps preferably all round it.

After fitting to the belt at its edge, the belt and the bead part can be made endless, as is typical for fitting over guide and/or drive rolls in upper feed and lower return runs. Specifically, see Figure ID, abutting (or interfitting if desired) ends 13A, B of the bead part can be hot-welded together in a suitable bonding station 50 that may be part of what serves further in jointing ends of 10A, B of the belt itself (whether or not aided

Claims

1. Conveyor belt with edging, the edging comprising a bead part engaging the belt only locally of the edge of the belt and having mutual mechanical interference fit adjacent said belt edge.

2. Conveyor belt with edging, according to claim 1, wherein the belt is of or for a corner or curve conveyor with said edging on the longest and outermost edge of the belt.

3. Conveyor belt with edging, according to claim 1 or claim 2, wherein the mutual mechanical interference fit is inboard of the said belt edge at not more than about 2.5% of the width of the belt.

4. Conveyor belt with edging, according to claim 1, 2 or 3, wherein the mutual mechanical interference fit is inboard of _<the said belt edge at not less than about 1.5% of the width of the belt.

5. Conveyor belt with edging, according to claim 3 or claim 4, wherein the mutual mechanical interference fit is at 10 to 12 millimetres or less inboard of said belt edge.

6. Conveyor belt with edging, according to claim 3, 4. or 5, wherein overall extent of the bead part inboard of said belt edge is not more than about 2.5%.

7. Conveyor belt with edging, according to claim 6, wherein overall extent of the bead part inboard of said belt edge is less than about 1.5%.

8. Conveyor belt with edging, according to any preceding claim, wherein guide or support or location engagement positions of the bead part are directly above said mechanical interference fit.

9. Conveyor belt with edging, according to any one of claims 1 to 7, wherein guide or support or location engagement positions of the bead part are immediately beyond said mechanical interference fit.

10. Conveyor belt with edging, according to any preceding claim, wherein the bead part has a slot to take said belt edge.

11. Conveyor belt with edging, according to claim 10, wherein the slot has a rib or tooth extending into the width of the slot, -and the belt has an edge-adjacent groove to receive said rib or tooth as said mutual mechanical interference fit.

12. Conveyor belt with edging, according to claim 11, wherein the slot rib or tooth is at the mouth of the slot.

13. Conveyor belt with edging, according to claim 10, wherein the slot and the belt have registering grooves and a strip member entrant both said grooves in affording ^' said mutual mechanical interference fit.

14. Conveyor belt with edging, according to any preceding claim, wherein said mutual mechanical interference fit is aided by adhesive at least at said interference.