GB2096492A

GB2096492A - Grader for articles

Info

Publication number: GB2096492A
Application number: GB8209445A
Authority: GB
Original assignee: Tickhill Engineering Co Ltd
Current assignee: Tickhill Engineering Co Ltd
Priority date: 1981-04-09
Filing date: 1982-03-31
Publication date: 1982-10-20
Also published as: GB2096492B

Abstract

An apparatus for conveying, cleaning or grading articles according to size comprises a flexible web (11) having a plurality of apertures therein, wave-forming means (19-22) adapted to cause the web (11) to adopt a continuously varying undulating form comprising waves travelling along the web (11) from one end (15) to the other end (16) so that each article placed on said one end (15) of the web (11) is caused to roll along the web by the wave motion thereof. <IMAGE>

Description

SPECIFICATION Grader for articles This invention relates to an apparatus which may be used for conveying, cleaning or grading articles according to size, and more particularly, but not exclusively, to an apparatus which may be used for conveying, cleaning or grading according to size tubers and root vegetables such as potatoes, turnips and the like.

It will be appreciated that vegetables are easily damaged by rough handling, for example being dropped or buffeted and thus it is an object of the invention to provide an apparatus for conveying, cleaning or grading articles according to size, which overcomes or reduces this problem.

According to the invention, we provide an apparatus comprising a flexible web having a plurality of apertures therein, wave4orming means adapted to cause the web to adopt a continuously varying undulating form comprising waves travelling along the web from one end to the other.

Thus each article placed on said one end of the web is caused to roll along the web by the wave motion thereof.

By providing for the web to extend from one location to another, the apparatus may thus be used as a conveyor.

It will be appreciated that root vegetables such as potatoes are usually covered in soil after harvesting and need to be cleaned. Any loose dirt on the articles tends to fall through the apertures in the web which is encouraged by the roiling of the articles which assists in the removal of such loose dirt. Thus the apparatus may be used as a cleaning machine. In this case, the web may extend from one location to another, or define a closed path.

The apertures in the web may be of varying size, the sizes of the apertures increasing from said one of the web to said other end. Thus the apparatus may be used as a grading apparatus for grading articles according to their size. In this case, each article placed on said one end of the web is thus caused to roll along the web by the wave motion thereof until it reaches a portion of the web having apertures of a size large enough for the article to drop through. A plurality of collecting bins may be placed beneath the web so that all of the articles received by a particular bin conform to a size range determined by the size of the apertures in the web above the particular bin.

It has been found that such an apparatus, when used to convey, clean or grade vegetables, considerably reduces the risk of damage to the vegetables because buffeting, which is normally associated with conveying, cleaning and grading apparatus is reduced.

Previously, it has been necessary to provide a separate cleaning and grading apparatus for articles although such an apparatus has been proposed which serves to convey articles. In the case of potatoes and other root vegetables, as the vegetab!es have needed to be loaded separately into each apparatus, a consequent increased risk of damage during handling has occured.

However in the apparatus according to the present invention, the necessity to provide separate cleaning and grading apparatus is aleviated because the apparatus, where the apertures in the web are of varying size, may serve both as a cleaning and grading apparatus as well as a conveyor where required, resulting in a significant further reduction in the risk of damage to the vegetables. Furthermore, costs for processing the articles are reduced as less machinery is required.

Preferably, the web comprises a pair of flexible edge members linked by transverse elongate elements. The transverse elongate elements may be equally spaced where the apparatus is merely used for conveying and/or cleaning or said spacing of the elements may increase from said one end to the other end of the web where the apparatus is used for grading.

The transverse elongate elements may comprise rods which are freely rotatable relative to the edge members.

The means which cause the web to adopt a continuously varying undulating form may comprise a pair of parallel endless chains or other conveying elements driven in synchronism and spaced by a distance approximately equal to the width of the web.

Each conveying element may carry a plurality of wave forming engagement means at spaced positions therealong, for engagement with the web. Each engagement means may engage said one end of the web as the engagement means enters a top run of the conveying elements.

Each engagement means may comprise a plurality of abutments around which the web may be engaged to form a wave, the abutments preferably comprising freely rotatable rollers, although any other suitable abutments may alternatively be provided.

The apparatus may also comprise guide means associated with said one end of the web and adapted to guide said one end into engagement with successive engagement means. The guide means may comprise lever means secured to said one end of the web and arranged to rock between limit positions in timed relation to the movement of the conveyor elements so as to direct the leading end of the web around the abutments of each engagement means to form a wave.

The guide means may include rotating cam means for rocking the lever means, the drive to said rotating cam means and the conveying elements being derived from a common drive source.

The invention will now be described in more detail with reference to the accompanying drawings in which Figure lisa side view of one side of an apparatus embodying the invention; Figure 2 is a plan view of the other side of the apparatus of Figure 1 with part of the casing broken away.

Referring to the drawings, an apparatus generally indicated at 10 comprises a web 11 and conveyor means generally indicated at 12. As can be seen from Figure 2 of the drawings, the web 11 comprises a pair of flexible side members 13 (only one of which can be seen) which carry a plurality of rods 14 therebetween which rods 14 are each rotatably mounted in the side members 13. Alternatively, the web 11 could comprise flexible side members having elongate transverse strips or slats extending therebetween which are not rotatable. Further alternatively, the web could comprise a mesh material having openings.

The main characteristic of the web 11 as shown, is that it provides apertures, the size of which increase from one end comprising a leading end generally indicated at 15, to the other end of the web comprising a trailing end 16. As shown, the separation between the rods 14 at an upstream position 17 is less than the separation at a downstream position 18 which is further down the web 11 towards the trailing end 16.

The actual spacings of the rods 14 are determined by the type of article to be handled and the use to which the apparatus is to be put. For example, in the apparatus shown, which is for use as a cleaning and grading apparatus, and where potatoes are to be cleaned and graded according to their size, the largest gap between the rods 14 is of the order of 12cm, whereas if the apparatus is to handle smaller vegetables such as carrots, the maximum spacing between the rods may be in the order of only 6cm.

Where the apparatus is to be used solely for cleaning and/or conveying, the spacing between the rods 14 may be constant and determined by the size of article to be cleaned.

The apparatus may be arranged so that the web 11 can be removed and replaced by a different web if required so as to provide a truly versatile apparatus.

The conveying means 12 comprises, in the example shown, a pair of chains 19 comprising conveying elements, which chains 19 are entrained about sprockets 20, 21, one of the sprockets, 20, being power driven so that the chains are rotated.

At positions along the chains 19, engagement means 22 are provided, each engagement means comprising a plate 23 carrying a plurality of rollers 24, 25, 26. The rollers are freely rotatable on the plates 23.

As will be seen from Figure 2, the web 11 has its side members 14 aligned with the positions of the groups of rollers 24, 25,26 on the engagement means 22. The leading end 15 of the web 11 is secured to the end of a lever arm 27 comprising two spaced parallel arms secured together by transverse pins. The lever arm 27 is pivotally mounted at a pivot 28 on a fixed part of the apparatus. The lever arm can thus rock about the pivot up and down between limit positions, which are shown in full lines and dotted lines in Figure 1 of the drawings.

When in the lowermost position shown in Figure 1 in full lines, the leading end 15 of the web is fed under the roller 25 of the engagement means 22. In the uppermost position shown in dotted lines in Figure 1, the engagement means 22 has moved to the dotted line position and the leading end 15 of the web has been lifted over the roller 26.

As the engagement means 23 is carried along the top run of the the chains 19, it will be seen that the web adopts an undulating form at each of the engagement means 22 so that the whole length of the web extending along the entire top run of the apparatus takes the form of a plurality of travelling waves, travelling in the direction of the arrows in Figure 1.

The function of the roller 24 is to guide the engagement means along a support plate 29 so as to prevent the conveyor from sagging.

Articles to be cleaned and graded according to size are placed on the web at a position near the leading end 15. As the waves 30 travel along the web, the articles are caused to roll along the web in advance of the waves until they reach a position along the web where the spacing between the rods 14 is large enough for the articles to fall through. Because of the rolling motion of the articles as they are conveyed along the web, any loose dirt tends to be broken off by the rods and will fall through the openings when the spacing between the rods permits this.

It will be seen from Figure 2 of the drawings that the conveyor means 12 are disposed at the sides of the web so that suitable bins or other receptacles can be provided underneath the web to receive articles as they are graded.

In order to operate the lever arm 27, a rotating two-armed cam 31 is provided which acts on a follower roller 32 at one end of the lever arm 27, the other end being attached to the leading end 15 of the web. The part of the lever arm 27 between the pivot 28 and the follower roller 32 is shorter than the other part of the arm which carries the leading end of the web 11. Taken in combination with the weight of the web acting on the longer portion of the lever arm 27, it will be appreciated that the lever arm 27 will normally adopt the lowermost position shown in Figure 1 of the drawings.

The cam 31 is caused to rotate by a drive belt 33 which encircles a drive wheel 34. The drive wheel 34 is keyed for rotation on a shaft 35 which also drives the sprockets 20 of the conveyor. Thus, the movement of the cam 31 is effectively synchronised with the movement of the conveyor means 12 so that the leading end 15 of the web 11 can be led around the rollers 24,25,26 as the engagement means 22 meet the leading end 15 of the web.

The cam 31 forces the follower roller downwardly, thereby lifting the leading end 15 of the web 11 over the roller 26 as shown in chain dotted out!ine in Figure 1. Once the follower roller 32 has been released by the arm of the cam 31,the lever arm 27 is free to drop to the full line lowermost position.

Other means could be provided for causing a series of waxes to move along the web 11. For example, the web could extend between pairs of side members which are sequentially raised and lowered to form waves which travel along the web 11. However, the arrangement described has the advantage of having relatively few driven moving parts. As referred to above, the web 11 can be removed and replaced according to the articles to be graded, the use to which the apparatus is to be put, of if the web becomes worn. This in no way affects the operation of the apparatus because the spacing and timing of the waves are controlled entirely by the positioning of the engagement means 22 on the chain 19 and on the drive speed of the shaft 35.Any change in the speed of the drive to the conveyor means 12 is transferred automatically to the rotating cam 31 so that the movement of the lever arm 27 is always in synchronism with the movement of the conveyor means.

Although in the example described, the apparatus comprises a combined grading apapratus and cleaning machine, it will be appreciated that if desired, by ensuring that the spacing between the rods 14 is equal, orthat apertures of equal size are provided along the web 11, the apparatus may be used solely for cleaning. In either case, i.e. whether the appratus is used for cleaning and grading or solely for cleaning, the apparatus acts as a conveyor conveying articles from the leading end 15 of the web on which they are placed, either to the other end 16 or into the respective grading bin placed beneath the web.

However, if desired, where the apparatus is used merely for cleaning and/or conveying, the web 11 may be a continuous web defining a circular or other closed path, by suitably modifying the apparatus.

Claims

1. An apparatus comprising a flexible web having a plurality of apertures therein, wave-forming means adapted to cause the web to adopt a continuously varying undulating form comprising waves travelling along the web from one end to the other.

2. An apparatus according to Claim 1 wherein the web extends from one location to another.

3. An apparatus according to Claim 1 wherein the web defines a closed path.

4. An apparatus according to Claim 1 or Claim 2 wherein the apertures in the web are of varying size, the sizes of the apertures increasing from said one end of the web to said other end.

5. An apparatus according to Claim 4 wherein a plurality of collecting bins are placed beneath the web so that all of the articles received by a particular bin conform to a size range determined by the size of the apertures in the web above the particular bin.

6. An apparatus according to Claim 1 or Claim 2 wherein the apparatus is a conveying and/or cleaning apparatus.

7. An apparatus according to Claim 1 or Claim 2 or Claim 4 or Claim 5 wherein the apparatus comprises a conveying apparatus and apparatus for grading according to size, or an apparatus for cleaning and grading according to size.

8. An apparatus according to any one of the preceding claims wherein the web comprises a pair of flexible edge members linked by transverse elongate elements.

9. An apparatus according to Claim 8 where dependant upon Claims 2, 3 or 6 wherein the transverse elongate elements are equally spaced.

10. An apparatus according to Claim 8 wherein dependent upon Claims 2 and 4 or Claim 7 wherein said spacing of the elements increases from said one end to the other end of the web.

11. An apparatus according to any one of Claims 8 to 10 wherein the transverse elongate elements comprise rods which are freely rotatable relative to the edge members.

12. An apparatus according to any one of the preceding claims wherein the means which cause the web to adopt a continuously varying undulating form comprise a pair of parallel endless conveying elements driven in synchronism and spaced by a distance approximately equal to the width of the web.

13. An apparatus according to Claim 12 wherein each conveying element carries a plurality of wave forming engagement means at spaced positions therealong, for engagement with the web.

14. An apparatus according to Claim 13 wherein each engagement means engages said one end of the web as the engagement means enters a top run of the conveying apparatus.

15. An apparatus according to Claim 13 wherein each engagement means comprises a plurality of abutments around which the web is engaged to form a wave.

16. An apparatus according to Claim 15 wherein guide means are associated with said one end of the web and adapted to guide said one end into engagement with successive engagement means.

17. An apparatus according to any one of Claims 13 to 16 wherein the abutments comprise freely rotatable rollers.

18. An apparatus according to Claim 17 wherein the guide means comprises lever means secured to said one end of the web and arranged to rock between limit positions in timed relation to the movement of the conveyor elements so as to direct the leading end of the web around the abutments of each engagement means to form a wave.

19. An apparatus according to Claim 18 wherein the guide means includes rotating cam means for rocking the lever means, the drive to said rotating cam means and the conveying elements being derived from a common drive source.

20. An apparatus substantially as heeinbefore described with reference to and as shown in the accompanying drawings.

21. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.