GB2170164A

GB2170164A - Conveying planar articles

Info

Publication number: GB2170164A
Application number: GB08502118A
Authority: GB
Inventors: Robert John Simmonds
Original assignee: BURTON GOLD MEDAL BISCUITS Ltd
Current assignee: BURTON GOLD MEDAL BISCUITS Ltd
Priority date: 1983-12-29
Filing date: 1985-01-29
Publication date: 1986-07-30
Also published as: GB8502118D0; GB2170164B

Description

SPECIFICATION Conveyor system The present invention concerns a conveyor system for conveying articles which are relatively flat. In particular the invention is concerned with conveying biscuits from a baking station to a stacking and packaging station. However there are many other potential applications such as transporting lids for attachment to cans in a canning factory.

A major problem when conveying large numbers of fragile articles is either the occurence of a blockage preventing free flow or intermittent interruption of the flow to enable stacking and packaging of the articles. With known conveyor systems this leads to a build up of pressure on the articles. Biscuits, for example, are extremely ill suited to withstand such pressure. Thus with soft biscuits such as digestives even the most advanced known conveying, stacking and packaging systems lead to a high proportion of broken and rejected biscuits.

It has been proposed to solve these problems by using conveyor systems which are entirely vibratory. However these are very expensive as many vibrators are needed, for example one vibrator for every two feet of conveyor. As the conveyor may be up to 100 feet long and many belts wide the expense of such a system is readily apparent.

The present invention has for an object the provision of conveyor apparatus, and a method of conveying articles, which reduces the above problems.

Accordingly from a first aspect the invention consists in a method of conveying planar articles comprising arranging the articles on a conveyor having a pair of relatively inclined, divergent conveying walls which are moved in the conveying direction, each article being carried by the conveyor walls in such a manner that during normal conveying each article lies in an inclined plane supported by the moving conveyor walls with neither its leading or its trailing edge in contact with any portion of the conveyor.

From a second aspect the invention consists in a conveyor having a pair of relatively inclined, divergent conveying walls, the arrangement being such that planar articles can be transported by the conveyor walls with each article during normal transport being supported only at points on its perimeter which are not either its leading or its trailing edge.

In order that the invention may be more clearly understood various embodiments thereof will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a perspective diagrammatic view of one embodiment of a conveying system according to the invention, Figure 2 is a section on line tt-tt of Figure 1 showing a biscuit being conveyed, Figure 3 is a diagrammatic section showing different stages of the operation of the conveyor of Figure 1, Figure 4 is an end view of a series of parallel conveyors according to the invention, Figure 5 is a perspective view of the drive system of one of the belts of Figure 4, Figure 6 shows some critical dimensions in relation to the size of articles being conveyed, and Figure 7 shows stacking apparatus which can be used with the conveying apparatus of the preceding Figures.

In the drawings Figure 1 shows a conveyor for circular biscuits and which comprises a pair of continuous conveyor belts 1 and 2. Belts 1 and 2 are inclined at 90 degree to one another and extend on either side of a stationary element 3. The inner runs of belts 1 and 2 are driven by drive rollers 4 to transport circular biscuits B in the direction of arrow A. Drive rollers 4 are in turn driven by a belt and reduction gearing arrangement 5 and electric motor 6.

As can be seen in Figure 1 the biscuit B is inclined in the conveying direction with its leading edge higher than its trailing edge, the latter not contacting element 3. The biscuit is supported at point contacts 7 with the belt walls. Thus if the biscuit hits an obstruction it will pivot about its contact points until its trailing edge contacts element 3. This pivotal or tipping movement will continue until the stopped biscuit comes to rest in a vertical position standing on the element 3. In this manner it is subjected to virtually no pressure from the still moving conveyor belts.

Figure 3 shows the sequence of attitudes of biscuit B as it encounters an obstruction. For the sake of clarity the biscuit is shown in different positions along the conveyor. At point 10 the biscuit is travelling normally with its trailing edge above element 3. At 11 the biscuit encounters an obstruction which may be a previously stopped biscuit or a member for stopping biscuits prior to packaging.

The obstruction causes the biscuit to pivot to firstly to the attitude shown at 11 and finally to that at 12.

The angle at which the biscuit reaches equilibrium and at which a stack of obstructed biscuits is formed is dependant on the relative dimensions of the biscuit, the stationary element on which it sits in equilibrium and the angle of the conveyor walls to one another. The latter will normally be 90 degrees. Figure 4 is an end view of two parallel conveyor runs 20 and 21. There may be many more such parallel runs as can be seen from Figure 5. In the embodiment of Figure 4 the element 3 is replaced by lips 22 projecting beyond the lower edges of belts 23. The distance marked D is important in setting the stack angle of the biscuits when they encounter an obstruction. It can also be seen that a horizontal biscuit 24 will touch the side walls of the conveyor runs, that is the distance between the uppermost edges of the runs is slightly greater than the diameter of the biscuits being conveyed.

Figure 6 shows a drive system for a single conveyor belt. The belt is toothed on its non-product carrying side and runs over a pair of end pulleys 31 inclined at 45 degrees. The belt is driven by a main drive pulley 32 which is in turn driven by a suitable drive source such as an electric motor (not shown). The drive pulley 32 has a horizontal axis

as do two idler pulleys 33 on either side of it.

Figure 7 shows a conveyor belt as previously described delivering biscuits 50 to a conventional stacking device which includes a guide 51. The stacked biscuits are collected by a short conveyor 52 having a series of slats 53 which carry individual biscuits till they are diverted by a knife-edged device 54 and loaded onto a further conveyor 55.

CLAIMS 1. A method of conveying planar articles comprising arranging the articles on a conveyor having a pair of relatively inclined, divergent conveying walls, each article being carried on the conveyor in such a manner that during normal movement the article lies in an inclined plane supported by the conveyor walls with neither its leading edge or its trailing edge in contact with any part of the conveyor.

Claims

2. A method as claimed in claim 1, wherein during normal movement the article is supported by the walls above a stationary element extending between the conveyor walls, the article on encountering an obstruction tipping about its points on contact with the conveyor walls to stand in a substantially upright position on the stationary element.

3. Apparatus for conveying relatively planar ar- ticles comprising a conveyor having a pair of rela- tively inclined, divergent walls on which the articles are conveyed, and a stationary element extending between the lower part of the conveyor runs on which an obstructed or stationary article being conveyed can rest in a substantially upright position whilst the conveyor walls continue to move.

4. Apparatus as claimed in claim 3, wherein the stationary element comprises a pair of lips each extending beyond the lowermost edge of an individual conveyor wall, each lip being at approximately 90 degrees to its associated conveyor wall.

5. Apparatus as claimed in claim 3, wherein the stationary element comprises a single element extending longitudinally between the lowermost portions of the conveyor walls.

6. Apparatus as claimed in any one of claims 3 to 5 and consisting of a plurality of parallel conveyor runs each having a pair of divergent conveyor walls and an intermediate stationary element.

7. Apparatus as claimed in claim 6 when dependant on claim 4, wherein for each conveyor run which has a similar conveyor run on either side thereof, the conveyor belts are mounted on a pair of inverted, substantially V-shaped members, the lips extending from the lowermost edges of the Vshaped members to stand proud of the conveyor walls.

8. Apparatus as claimed in any one of claims 3 to 7 wherein each belt is toothed on its non-conveying side, the toothed side engaging with a drive pulley.

9. Apparatus as claimed in claim 8, wherein the drive pulley for each belt has a substantially hori- zontal axis.

10. Apparatus as claimed in claim 9 wherein on either side of each drive pulley the associated belt passes over an idler pulley also having a substantially horizontal axis.

11. A method of conveying planar articles substantially as hereinbefore described with reference to the accompanying drawings.

12. Apparatus for conveying planar articles substantially as hereinbefore described with reference to the accompanying drawings.