WO1994014687A1

WO1994014687A1 - Conveyor belt

Info

Publication number: WO1994014687A1
Application number: PCT/GB1993/002399
Authority: WO
Inventors: Keith Leslie Daw
Original assignee: Chiorino Uk Limited
Priority date: 1992-12-24
Filing date: 1993-11-22
Publication date: 1994-07-07
Also published as: AU5568294A; CA2152613A1; GB9226912D0; EP0675844A1

Abstract

The present invention relates to conveyor belts and conveyors. The invention provides a conveyor belt (2) comprising a conveyor side (6), a reverse side (8) opposite to the conveyor side and at least one generally transverse opening (10) in the belt (2); and a support member (12, 44) separate from the belt (2), at least part (32, 46) of which support member (12, 44) projects through the opening (10) to provide a flight (14) extending from the plane of the belt (2) on the conveyor side (6) and means cooperating between the support members (12, 44) and the opening (10) to allow the support member (12, 44) to be moved to lie substantially parallel to and against the conveyor side (6) of the belt (2) whereby the support member (12, 44) can pass a tension roller (20) engaging the conveyor side (6) of the belt (2).

Description

CONVEYOR BELT

Field of the Invention

The present invention relates to conveyor belts and conveyors.

Background to the Invention A conveyor will usually comprise an endless belt having a conveyor surface, the belt passing around guide rollers at both ends of its path. A tension roller is often provided on the return length of the conveyor path to maintain tension in the belt. The tension roller bears on the conveyor surface side of the belt.

It is now common, especially in belts which have to convey articles up an incline, for flights to be provided to avoid slippage of articles on the conveyor surface. Where the tension roller is not adapted to operate with the flights, for instance where the conveyor was not designed for use at an incline or where a new design of belt is being used, the flights will collide with the tension roller as they pass it causing wear and/or damage to the tension roller and/or the flights. In an attempt to overcome this problem, United States Patent No 4,911,286 suggests the use of tongues cut from the belt, ie a generally U-shaped cut being made, and a projection being disposed at the trailing edge of the tongue to act as a flight. The tongue can effectively pivot about its end, still connected to the belt, so that, as it contacts the tension roller, the flights move away from the roller to reduce wear and/or damage.

However, it has been found that this continual flexing of the belt leads to fatigue problems associated with the belt material. Summary of the Invention

According to the present invention, there is provided a conveyor belt comprising a conveyor side, a reverse side opposite to the conveyor side and at least one generally transverse opening in the belt; and a support member separate from the belt, at least part of which support member projects through the opening to provide a flight extending from the plane of the belt on the conveyor side and means cooperating between the support member and the opening to allow the support member to be moved to lie substantially parallel to and against the conveyor side of the belt whereby the support member can pass a tension roller engaging the conveyor side of the belt.

Such an arrangement has the advantages that it reguires a minimum of modifications to the belt, there is less flexing of the belt material substantially reducing fatigue and, if the support member becomes worn or if particular shapes are required, the support member can be replaced very easily.

In a preferred construction, the support member is generally L-shaped in cross-section, comprising a body and a foot attached to the body, the foot being generally perpendicular to the body whereby, in use, the body extends generally perpendicular to the conveyor side of the belt, the foot extends generally parallel to the reverse side and when the body lies generally parallel to the conveyor side, the foot extends generally perpendicular to the reverse side. This construction provides a simple and effective means for reversing the position of the support member to enable it to pass the tension roller and to relocate the flight on the belt as the foot engages a guide roller at one end of the belt' s path before returning to the conveying portion of its path. The belt and support member have been found to provide the correct degree of resistance to articles placed on the belt on the conveyor side while being moved by the tension roller with minimal difficulty if the means cooperating between the support member and the belt include slots each extending from either end of the stop at the juncture of the body and the foot. Preferably, the opening comprises circular holes through the belt at either end of a slit and the slots in the support member terminate in generally circular holes the centres of which are spaced apart by the distance between the centres of the holes at either end of the slit. The holes through the belt help to prevent tears.

The support member is positioned in the opening such that the foot trails the body as the conveyor belt moves.

The support member may comprise a body and foot of equal length with each of the body and foot comprising a generally rectangular plate. However, in some cases the support member may include two feet depending from the body such that the belt includes two aligned openings through which the feet project. In this way an elongate flight can be produced without requiring such a long slit to be cut into the belt. In some cases this is necessary to maintain the strength of the belt. The support member may have cut away edges in order to prevent the support member catching on parts of the conveyor belt.

The support member may be of any material of sufficient strength and resilience. In some cases the support member is a polyurethane but it may include a polyester liner to reduce friction.

It will be apparent to the skilled addressee of the specification that the length of support member, height of body and depth of foot will be varied in accordance with its intended use.

According to the present invention, there is also provided a conveyor comprising a conveyor belt according to the preceding paragraphs. According to the present invention, there is also provided a support member adapted for use as a flight with a conveyor or conveyor belt according to the preceding paragraphs. The invention is particularly advantageous when used for inclined conveyors.

Brief Description of the Drawings

Two examples of the invention will now be described, by way of example only, with reference to the drawings that follow; in which:-

Figure 1 is a schematic side elevational view of a conveyor in accordance with the present invention; Figure 2 is a schematic enlarged plan view of part of a conveyor belt for use with the present invention; Figure 3 is a schematic enlarged perspective view of a first support member for use with the present invention; Figure 4 is a schematic enlarged side elevational view of the present invention showing the support member in its conveying and "rest" positions. Figure 5 is a schematic enlarged perspective view of a second support member for use with the present invention.

Description of the Preferred Embodiments

Referring to Figures 1-3 of the drawings, there is shown a conveyor belt 2 comprising a conveyor side 6, a reverse side 8 opposite to the conveyor side 6 and at least one generally tranverse opening 10 in the belt 2; and a support member 12 separate from the belt 2, at least part of which support member 12 projects through the opening 10 to provide a flight 14 extending from the plane of the belt 2 on the conveyor side 6 and means cooperating between the support member 12 and the opening 10 to allow the support member 12 to be moved to lie substantially parallel to and against the conveyor side 6 of the belt 2 so that it can pass a tension roller 20 engaging the conveyor side 6 of the belt 2.

In Figure 1, a conveyor 4 carrying the belt 2 is shown inclined at an angle of about 40 degrees to the horizontal. The conveyor 4 has guide rollers 22, 24 at either end of the path of the belt 2, either one or both of which guide rollers 22, 24 can be driven by known means. The length of the belt 2 between the guide rollers 22, 24 on the side opposite the tension roller 20 comprises a conveyor portion 16. The guide rollers 22, 24 engage the reverse side 8 of the belt 2, while the tension roller 20 engages the conveyor side 6 of the belt 2, the belt 2 is driven in the direction indicated by arrow F. The belt 2 is formed from a polyurethane material having elastic resilience, or from other such materials well known to those skilled in the art. The belt 2 is 2 millimetres thick.

The opening 10 is shown in more detail in Figure 2 and comprises an elongate slit 26 terminating, at either end, in holes 28, 30. The opening 10 is cut or formed in the belt 2 to be of minimal width. However, the width of opening 10 may be adjusted to improve the performance of the support member 12. The holes 28, 30 are cut, drilled or otherwise formed in the belt 2 to have a diameter to suit the thickness of the belt 2. The distance A between the centres of the holes 28, 30 is dependent on the width of the belt 2; in this case it is 100 millimetres. Figure 3 shows the support member 12 in more detail. The support member 12 is produced by injection moulding, extrusion and/or high frequency welding from a plastics material such as polyurethane. The support member 12 comprises a body portion 32 and a foot 34 extending generally perpendicular from the body 32 to form a substantially L-shaped elongate member. The height B of the body 32 in this embodiment is 50 millimetres. The height B is chosen so that it is sufficient to convey articles 44 up the incline of the conveyor 4 while being short enough relative to the tension roller 20 to be rotated into its non-conveying "rest" position as described below. Generally, the height B of the body portion 32 should be no more than the radius of the tension roller 20. However, larger body portions 32 have been found to work.

The length C of the foot 34 in this embodiment is 25 millimetres. The length C is chosen to keep material and manufacturing costs to a minimum. The length C of foot 34 must be sufficient to hold the support member 12 in position when it is inserted in the opening 10 (as described below) and to allow the guide roller 22 to rotate the body into its conveying position (as described below). The maximum length C of the foot 34 should be the radius of the guide roller 22. Larger feet 34 can work.

At the juncture of the body 32 and foot 34 are two substantially parallel rectilinear slots 36, 38 terminating in holes 40, 42. The two slots 36, 38 are substantially identical so only one of them will be described here for convenience. Slot 36 extends from one end of the support member 14 part of the distance towards the centre of the support member 14 and terminates in the hole 40. The slot width D in this embodiment is 2 millimetres and is chosen to be equal to the thickness of the belt 2. The hole 40 has a diameter of 3 millimetres (chosen to be 1 millimetre greater than the width of the slot 36) which is equal to the radius of the holes 28, 30 in the belt 2. The slot 36 and hole 40 are formed eg as part of an injection moulding, or in post production from an extrusion at 45 degrees to the planes of the body 32 and foot 34, ie the slot 36 and hole 40 are symmetrical about the juncture of the body 32 and foot 34. The holes 40, 42 are spaced apart by a distance E which, in this embodiment, is 100 millimetres, ie the same as the spacing A between the holes 28, 30 in the belt 2.

To insert the support member 12 into the opening 10 in the belt 2, the support member 12 is forced through the opening 10, relying on the elasticity of the material of the belt 2, until the belt 2 springs back into the slots 36, 38 thereby holding the support member 12 in position. Either the body 32 can be forced through from the reverse side 8 or the foot 34 can be forced through from the conveyor side 6. In this position, the holes 28, 30 and the belt 2 and holes 40, 42 in the support member 12 overlap. Ideally, the axes of the holes 28 and 42 intersect as do the axes of the holes 30 and 40. However, given the manufacturing tolerances to which the support member 12 and opening 10 can be formed, while keeping the costs of manufacture down, this will not always be possible. However, the holes 28 and 42 should overlap as should the holes 30 and 40.

In order that the support member 12 can be inserted into the opening 10, it will be appreciated by those skilled in the art that the distance A between the holes 28 and 30 (which is the same as the distance E between the holes 40, 42) needs to be large enough to permit the support member 12 to be inserted in the openin.g 10 without stretching the belt 2 beyond its elastic limit. If necessary, the foot 34 can be narrower than the body 32 to aid in this insertion into the opening 10.

Referring now to Figures 1 and 4, the operation of the present invention will now be explained.

In Figure 1, the support members on the conveyor portion 16 of the belt 2 have the bodies 32 of each of the support members 32 upstanding from the belt 2 so that the support members 12 form flights 14 generally perpendicular to the plane of the conveyor portion 16 of the belt 2. In this position, the flights 14 can be used to prevent articles 44 such as parcels, food products etc, from slipping down the belt and drive them in the direction indicated by arrow F. The feet 34 of each of the support members 12 can be seen on the reverse side 10 of the conveyor belt 2 lying generally parallel to and against the belt 2. Surprisingly, it has been found that the arrangement of slit 10 and slots/holes 36, 38, 40 and 42 (together comprising the cooperating means ) interengage sufficiently to prevent the support member 12 from being rotated, in Figure 1 in an anti-clockwise direction, so that the body 32 lies against the conveyor side 6 of the belt 2. If this were to happen, the support members 12 would, effectively, cease to perform their function as flights 14.

The support members 12 continue in their path around guide roller 24. The support members 12 do not interfere with the operation of guide roller 24 as they pass around it because the feet 34 of the support members 12 which project on the reverse side 8 of the belt 2, and hence engage guide roller 24, are lying generally parallel to and against the surface of reverse side 8. The additional thickness of the feet 34 can be taken up by the resilience and elasticity of the belt 2. The support members 12 then continue towards the tension roller 20. As referred to above, if the support members 12 were to remain in the position they adopt along the conveyor portion 16 of the belt 2 as they pass the tension roller 20, damage and/or wear would occur between the tension roller 20 and the support members 12. However, as the top of the body 32 engages the tension roller 20, the support member 12 is rotated from its conveying position to its "rest" position (as shown in ghost-lines in Figure 5). The tension roller 20 rotates the support member 12 whereas the articles 44 do not because: (1) the tension roller is fixed in place and hence provides a greater resistance to the support members 12; and (2) the tension roller 20 engages the top of the body 32 causing a larger turning force than that caused by the articles 44 which, typically, engage the body 32 nearer its juncture with the foot 34.

Thus, the support member 12 is rotated to its "rest" position, in which the body 32 lies generally parallel to and against the conveyor side 6 of the belt 2, by the tension roller 20 allowing it to safely pass the tension roller 20 in the same way as foot 34 passed the guide roller 24. In this "rest" position, the foot 34 is upstanding from the reverse side 8 of the belt 2, ie the reverse of the conveying position of the support member 12.

The support members 12 next engage the other guide roller 22 which performs the opposite operation to tension roller 20 and rotates the support members 12, referring to Figure 1 in a clockwise direction, to return the support members 12 to their conveying position. As this operation is substantially the same as that described above in relation to tension roller 20, it will not be repeated here.

The operation described above is then repeated as the belt 2 continues around the guide rollers 22, 24. In the event that a support member 12 needs to be changed, it can easily be removed by following the reverse of the insertion steps referred to above and then replaced by a new support member 12. Similarly, support members of different widths, shapes and/or materials can be inserted for other applications.

A second embodiment of the invention is illustrated in Figure 5 which shows a second example of a support member for use with a conveyor belt. The support members 44 is produced from a sheet of polyurethane material having elastic resilience lined with a polyester liner to cut down friction. A shape is cut from the sheet of material and the feet are then heat formed to the perpendicular as shown in Figure 5. The support member 44 comprises a body portion 46 and two feet 48, 50 both extending generally perpendicularly from the body 46 to form a substantially L-shaped elongate member. The length F of the body is 30cm. The feet 48, 50 are of unequal length with the foot 48 being attached to the body 46 along G which is equal to 4.7cm. The longer foot 50 is connected to body 46 by distance H equal to 9.6cm. In order to cooperate with a conveyor belt, two slots of length 4.7cm and 9.6cm are cut into the belt which are colinear. This allows for a long body to be used to provide an elongate flight but without requiring an extremely long opening to be cut. For instance, in the example shown, if the foot was a one piece foot the length of the opening required would be equal to length I which is 24.5cm which would considerably weaken any conveyer belt into which it was placed. The different lengths of the feet 48, 50 are chosen dependent upon other parts of the apparatus into which the conveyor is to be installed. Here the height J of the body is equal to 5.1cm with the beam being 2.2cm.

As can be seen, at the junction of the body 46 and the feet 48, 50, are three rectilinear slots 52, 54, 56. These are substantially parallel and do not terminate in a hole since the two layer material used for this support member will not wear. The material is flexible but resilient to allow for ready insertion into a conveyor belt. The use of two feet of shorter length aids insertion into the belt.

It can be seen that the body 46 is not rectangular, it has curved edges to ensure that these do not catch upon parts of the apparatus in connection with which the conveyor is to be used.

Claims

1. A conveyor belt (2) comprising a conveyor side (6), a reverse side (8) opposite to the conveyor side and at least one generally transverse opening (10) in the belt (2); and a support member (12, 44) separate from the belt (2), at least part (32, 46) of which support member (12, 44) projects through the opening (10) to provide a flight ( 14) extending from the plane of the belt (2) on the conveyor side (6) and means cooperating between the support member (12, 44) and the opening (10) to allow the stop (12, 44) to be moved to lie substantially parallel to and against the conveyor side (6) of the belt (2) whereby the support member (12, 44) can pass a tension roller (20) engaging the conveyor side (6) of the belt (2).

2. A conveyor belt according to claim 1, in which the support member (12, 44) is generally L-shaped in cross- section, comprising a body (32, 46) and a foot (34, 48, 50) attached to the body (32, 46), the foot (34, 48, 50) being generally perpendicular to the body (32, 46) whereby, in use, the body (32, 46) extends generally perpendicular to the conveyor side (6) of the belt, the foot (34, 48, 50) extends generally parallel to the reverse side (8) and when the body (32, 46) lies generally parallel to the conveyor side (6), the foot (34, 48, 50) extends generally perpendicular to the reverse side (8) .

3. A conveyor belt according to claim 2, in which the means cooperating between the support member (12, 44) and the opening (10), include slots (36, 38, 52, 56) each extending from either end of the support member (12, 44) at the juncture of the body (32, 46) and the foot (34, 48, 50), the distance between the ends of the slots (36, 38) being equal to the length of the opening ( 10 ) in the belt ( 2 ) .

4. A conveyor belt according to claim 3, in which the opening (10) comprises a slit (26) which includes at either end circular holes (28, 30) and the slots (36, 38) in the support member^" (12) terminate in generally circular holes (40, 42) the centres of which are spaced apart by a distance equal to the distance between the centres of the holes (28, 30) at either end of the slit (26).

5. A conveyor belt according to any one of claims 2 to 4, in which the belt (2 ) includes at least two colinear openings, and in which the support member (44) includes at least two parallel spaced apart feet (48, 50) extending from the support member (44).

6. A conveyor including a conveyor belt according to any one of the preceding claims.

7. A support member adapted for use as a flight with a conveyor or conveyor belt in accordance with any one of the preceding claims.

8. A conveyor belt arranged substantially as described herein with reference to, and as illustrated in Figures 1 to 4 of the accompanying drawings.

9. A conveyor belt arranged substantially as described herein with reference to, and as illustrated in

Figures 1 to 4, when modified in accordance with Figure 5 of the accompanying drawings.