GB2160124A

GB2160124A - Grading apparatus

Info

Publication number: GB2160124A
Application number: GB08514309A
Authority: GB
Inventors: J C Hooley; A M Cooke
Original assignee: Tickhill Engineering Co Ltd
Current assignee: Tickhill Engineering Co Ltd
Priority date: 1984-06-08
Filing date: 1985-06-06
Publication date: 1985-12-18
Also published as: GB8414662D0; GB2160124B; GB8514309D0

Abstract

A grading apparatus for grading articles comprising a grading surface comprising a plurality of spools, each having a longitudinal axis which extends transversely of the surface, the spools being spaced apart longitudinally of the surface and being of a configuration so as to provide a plurality of grading apertures, between adjacent spools and adjustable means to vary the distance between adjacent spools in a direction longitudinally of the grading surface. The grading surface may be provided by chain conveyors, comprising a plurality of spools, the spools being spaced apart longitudinally of the surface and extending between spaced parallel chains each of which comprise a plurality of links between adjacent spools, wherein the mutual angular orientation of the links is variable so as to vary the spacing between the spools by means of a cam follower fixed relative to alternate ones of the links.

Description

SPECIFICATION Grading apparatus This invention relates to grading apparatus for grading articles according to size, for example, crop such as potatoes, onions, turnips, red beet and the like.

One known form of grading apparatus is a web grader in which an endless belt provided with a plurality of square apertures is shaken to distribute crop on the belt and cause crop of appropriate size to fall through the apertures. This type of grader suffers from the disadvantage that the crop can be damaged by the shaking action of the belt and it also requires laborious changing of the whole belt when a different grading size is required.

Another known form of grading apparatus is a spool grader which comprises a grading surface comprising a plurality of spools each having a longitudinal axis which extends transversely of the surface and which are spaced apart longitudinally of the surface and are of such a configuration as to provide a plurality of grading apertures between adjacent pairs of spools.

In order to change the size of the grading apertures, adjacent spools are moved relative to each other in a direction parallel to their longitudinal axes but this causes the shape of the grading apertures to be changed, reduces the accuracy of sizing and damages the produce by friction In addition, there is a tendency for spool graders to be blocked by irregularly shaped crop such as tubers or bulbs.

An object of the invention is to provide a new and improved grading apparatus whereby the above mentioned problem is overcome or is reduced.

According to the present invention, we provide a grading apparatus for grading articles comprising a grading surface comprising a plurality of spools each having a longitudinal axis which extends transversely of the surface, the spools being spaced apart longitudinally of the surface and being of a configuration so as to provide a plurality of grading apertures between adjacent pairs of spools and adjustable means to vary the distance between adjacent spools in a direction longitudinally of the grading surface.

According to another aspect of the present invention we provide a grading apparatus for grading articles comprising a chain conveyor providing a grading surface comprising a plurality of spools each having a longitudinal axis which extends transversely of the surface and being of a configuration so as to provide a plurality of grading apertures between adjacent pairs of spools, the spools being spaced apart longitudinally of the surface and extending between spaced parallel chains each of which comprises at least two links between each pair of adjacent spools, the mutual angular orientation of the links being variable, to vary the spacing between the spools, by means of a cam follower fixed relative to one of the links and engageable with a cam surface which is adjustable to vary the distance between the cam surface and the plane of the grading surface thereby permitting adjustment of the spacing of the spools in a direction longitudinally of the grading surface.

The spools may be caused to rotate as a result of longitudinal movement of the spools along the grading surface.

The apertures defined between the spools may be of generally square configuration with the full extent of at least two sides of the square being provided by surface parts of the spools.

The spools may be carried on shafts which are supported by spool shaft rails.

Each spool shaft may have spool shaft carriers which are engaged with the rail.

The spool shaft carriers may be rotatable relative to the shaft.

In the first aspect of the invention the spool shafts may be interconnected in a continuous chain by links.

In the second aspect of the invention the spool shafts may be interconnected in said chain by links.

The chain may be engaged around at least two rotatable driving members.

One of the two driving members may be located at one end of the apparatus, a forward end, and the other of the two located at the opposite end of the apparatus, a rearward end.

The location of the members may be such that the chain of spools move from the rearward end to the forward end of the appparatus on the top run of the chain.

Each spool may comprise a first frusto-conical part and a second frusto-conical part of generally larger diameter with an intermediate frusto-conical part therebetween.

The surface of the intermediate frusto-conical part and the surface of the second frusto-conical part may cooperate with corresponding surfaces of an adjacent spool to define a grading aperture therebetween.

The region of join between the frusto-conical parts may be of smooth curved configuration.

The spools may comprise spool sections.

Each spool section may be made as a moulding in a suitable material.

The material may be rubber.

Each spool section may be provided with a central passage in which is received the spool shaft.

The central passage and spool shaft may be of a substantially square cross-section.

One end of the spool shaft may be fixed to an associated spool shaft carrier.

The spool shaft carrier may have a circular crosssection surface portion which runs on the spool shaft rail.

In the first aspect when the spool shafts are interconnected in a chain by links, said links may comprise a plurality of first links and a plurality of second links, the first links carrying and being pivotally connected to said support shafts and being pivotally connected to the second links about the axis of pivotal connection to the spool shafts, the chain may also comprise a plurality of first and second intermediate links, each first link being piv otally connected to a second intermediate link and each second link being pivotally connected to a first intermediate link and each adjacent pair of first and second intermediate links being pivotally connected together, each first link and each first intermediate link may have a cam follower fixed relative thereto and engageable with a cam surface which is adjustable to vary the distance between the cam surface and the plane of the grading surface thereby permitting adjustment of the spacing of the spools in a direction longitudinally of the grading surface.

In the second aspect when the spool shafts are interconnected in said chain by links, said links may comprise a plurality of first links and a plurality of second links, the first links being pivotally connected to and carrying said spool shafts and being pivotally connected to the second links about the axis of pivotal connection to the spool shafts, the chain may also comprise a plurality of first and second intermediate links, each first link being pivotally connected to a second intermediate link and each second link being pivotally connected to a first intermediate link and each adjacent pair of first and second intermediate links being pivotally connected together, each first link and each first intermediate link may have said cam follower fixed relative thereto which is engageable with said cam surface.

The first chain links may comprise a pair of spaced parallel members each having an aperture at one end thereof.

A bearing, carried on the spool shaft, may be re çeived in the apertures.

The second chain links may comprise a pair of spaced parallel members, the bearing being received in apertures provided at one end of said pair of spaced parallel members.

The cam follower may be provided on an element extending laterally from each of said first links and each of said first intermediate links.

The cam followers may be in engagement with first and second cam surfaces.

Each cam surface may be provided by a surface of a cam member of inverted T cross-section.

The cam follower may be in engagement with a first cam surface at the rearward end of the apparatus and in engagement with a second cam surface at the front end of the apparatus.

A surface of a cam link may be provided between the first and second cam surfaces, said cam link being pivotally connected to the first cam member and pivotally and slidably connected to the second cam member, to permit of independent adjustment of the height of said cam members.

The angle of relative inclination of adjacent links may be adjustable by adjusting the height of the first and second cam surfaces thereby allowing adjustment of the spacing between adjacent spools.

Conveyors may be provided beneath the grading surface for articles which pass through the grading apertures.

An exit chute may be provided at the forward end of the apparatus to discharge articles which have not passed through the grading apertures, and at the rearward end of the apparatus, is provided with a feed chute down which an article to be graded is fed onto the grading surface.

One embodiment of the invention will now be described by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a side elevation, with parts omitted for clarity, of a grading apparatus embodying the invention; Figure 2 is an end elevation of the apparatus of Figure 1 looking in the direction of the arrow A; Figure 3 is a fragmentary cross-sectional view, to an enlarged scale, on the line 3-3 of Figure 1; and Figures 4a and 4b are diagrammatic plan views of the apparatus of Figure 1 showing different sizes of grading aperture.

Referring to the drawings, a grading apparatus for grading crops, such as potatoes, onions, turnips, red beet, bulbs, corms and the like.

The apparatus comprises a frame 10 comprising a longitudinally extending base part 12, vertical columns 14 which carry an intermediate part 16 which supports intermediate vertical columns 18.

The frame also includes a base transverse member 20, an intermediate transverse member 22 carried by the columns 14 and three sub-transverse members 24 carried by the middle column 14 and further columns 18. Supported on the sub-transverse members 24 is a spool shaft rail 26 of channel configuration and supported by braces 28 extending between the rail 26 and each of the sub-transverse members 24. As best shown in Figure 2, two such spool shaft rails 26 are provided, one on each side of the apparatus.

Supported on the upper flange 30 of each spool rail 26 are spool shaft carriers 32 which are interconnected, as hereinafter to be described, in a continuous chain by links 34, 34a, 36, 36a. The resultant chain is engaged around two pairs ot driving drums 38, 40, the pair 38 being disposed at the forward end F of the apparatus and the other pair 40 being disposed at the rearward end R of the apparatus.

The drums 38, 40 are rotated, clockwise in Figure 1, so as to move the chain of spools from the rearward end to the forward end of the apparatus on the top run of the chain. As best shown in Figure 3, the spool shaft carriers 32 each carry a spool shaft 42 which carries a spool 44. Thus, the adjacent spools 44 provide a grading surface which extends longitudinally between the rearward and forward ends of the apparatus and transversely between the spool shaft carriers 32 at opposite sides of the apparatus. The spools are of a configuration so as to define between adjacent spools grading openings 46, see Figures 4a and 4b, of generally square configuration of a size appropriate to the grading operation to be performed. The spacing between adjacent spools in the longitudinal direction of the apparatus is adjustable to permit of adjustment of the size of the grading apertures 46.

The chain drive link drums 38, 40 are provided with a plurality of part-circular recesses 47 in their periphery which receive rollers 48 provided between adjacent links 34, 34a, 36, 36a and the drums are fixed to a shaft 50 which is driven via a driving muff 52 from gearbox 54 which is driven by a chain drive 56 from an electric motor 58 mounted on the base part 12 of the frame 10.

Extending longitudinally of the apparatus from the gearbox 54 is a transfer shaft 60 which drives a further gearbox 62 at the rearward end of the machine through a dog clutch 64 which is disengageable to permit of relative rotation of the drive drums 38 relative to the drive drums 40 which are driven by the gearbox 62, and are of a configuration similar to the drive drums 38 at the forward end of the apparatus.

Each spool 44 comprises a plurality of pairs of individual spool sections 44a, adjacent sections being oppositely orientated and the spool sections in adjacent spools being alternately disposed so as to co-operate to produce the generally square in cross-section grading openings 46. There are further openings, such as that indicated at 66, when the openings 46 are greater than their minimum size between adjacent spools in the grading surface but as these are of smaller cross-section than the grading apertures 46, they do not interfere with the accuracy of the grading.

Each spool comprises a first frusto-conical part 46a and a second frusto-conical part 46b of generally larger diameter with an intermediate frustoconical part 46c therebetween. The region of join between the frusto-conical parts being of smooth curved configuration. The surface of the intermediate frusto-conical part 46c and the surface of the part 46b cooperate with corresponding surfaces of an adjacent spool to define a grading aperture 46 therebetween. It will be seen that the surfaces of the parts 46b overlie the surfaces of the parts 46a as shown at X and Y in Figures 4a and 4b.Thus the surfaces of the parts 46b of adjacent spools provide the full length of two opposite sides of each square grading aperture 46 and this ensures good grading performance, even though the remaining two opposite sides of each square aperture 46 are provided only partially by the surfaces of the parts 46c.

Each spool section 44a is made as a moulding in a suitable material, such as rubber, and is provided with a central passage of square cross-section in which is received the spool shaft 42 which is square and tubular. At its opposite end, each spool shaft 42 is fixed by set screws 70 to an associated spool shaft carrier 32 having a circular cross-section, in the present example cylindrical, surface portion 72 which runs on the spool shaft rail 26, and having an outwardly extending flange 74 to locate the spool shaft laterally. Each spool shaft carrier 32 carries a needle roller bearing 76 which rotatably mounts a pivot shaft 78 which extends within the spool shaft 42 and has a reduced diameter end portion which interconnects chain links 34, 36.

As best shown in Figure 3, each first chain link 34 comprises a pair of spaced parallel members each having an aperture 80 at one end in which is received a bearing 82 carried on the reduced diameter part 84 of the shaft 78. Each second chain link 36 likewise comprise two spaced parallel members having apertures 86 at their one ends, received on a sleeve 88 journalled on the bearing 82. Between the members of the links 36 is the roller 48.

At their other ends, the links 34, 36 are interconnected by a stub shaft (not shown) carrying a further roller 48.

Welded to the members of the link 34 are two further link members 90 provided with clearance openings 92 at their one ends, and carrying a stub shaft 94 at their other ends on which is journelled a cam following roller 96 which is in engagement with a cam surface on a cam member 98 at the rear of the machine and a cam surface on a cam member 100 at the front of the machine.

Between the connected together pairs of first and second links 34, 36 are intermediate first and second links 34a, 36a respectively. These links are similar, respectively, to the links 34 and 36 but instead of the members of the first intermediate links 34a receiving bearings carried on pivot shaft 78, they receive bearings carried on stub shafts (not shown) which carry still further rollers 48. The members of each of the first intermediate links 34a have welded thereto two further link members 90a which carry a further cam follower roller 96a in the same way as do the members of the links 34 carry the rollers 96. The rollers 96a engage the cam surfaces provided on the cam members 98, 100 in the same way as do the rollers 96.

Although in this example four links have been described as being provided between each adjacent spool, if desired a different number of links could be provided, either less or more, and in particular it is possible to provide only two links, for example links corresponding to the links 34 and 36 described hereinbefore with the first and second intermediate links 34a, 36a being dispensed with.

In this case a first link 34 at the opposite end thereof which carries a spool would be connected to the non-spool carrying end of an adjacent second link.

In the present example it is preferred to provide four links to enable a desired extent of adjustment in the spacing of the spools but if a lesser amount of adjustment is acceptable then the above mentioned arrangement with two links between each spool may be provided. If, on the other hand, an even greater spool separation adjustment requirement is required then a greater number of links than four may be provided.

The cam members 98, 100 are of inverted T-section, the stem of the T being connected by a pin 102 to a clevis 104 which is rotatably connected to a shaft 106 having a threaded shank 108 in engagement with a nut 110 fixed to an upper member 112 of the frame 10, and provided with a locknut 114. The shank 108 is provided with a square end portion 116 with which a tool can be engaged to rotate the shank and thus to adjust the position of the cam members 98, 100 relative to the rail 26.

A cam surface is provided on a connecting link 118 which is provided between the cam members 98, 100 and is pivotally connected to the cam member 98 and pivotally and slideably connected to the cam member 100 to permit of independent adjustment of the height of the two cam members. It will of course be appreciated that there is a cam member 98, 100 provided at each of the opposite sides of the apparatus.

Beneath the upper run of the spools which provide the grading surface, are provided two conveyors for articles which have passed through the grading openings 46, these are indicated at 120 and 122, the conveyor 120 is disposed under the part of the grading surface, the size of the apertures of which is controlled by the rearward cam member 98, and the conveyor 122 is disposed under the part of the grading surface, the spacing of which is controlled by the cam member 100. The conveyors 120, 122 convey articles which have passed through their respective grading apertures in a direction transversely of the grading surface.

At the forward end of the apparatus, an exit chute 124 is provided to discharge articles which have not passed through the grading openings, whilst at the rearward end of the apparatus, a feed chute 126 is provided down which crop to be graded is fed onto the grading surface.

In use, the motor 58 drives the transverse shaft 60 via the chain drive 56 and hence rotates the chain drive drums 38 and 40 via the gearboxes 54 and 62, thereby causing the spools to be moved in the upper run of the conveyor from the rearward end towards the forward end of the conveyor.

The cam follower links 90 are constrained to adopt a particular angle relative to the spool shaft rail by virtue of engagement of the cam follower rollers 96, 96a with the cam members 98, 100 and this causes the links 34, 34a to adopt a complementary angle, i.e. one inclined at 90 to the angle of the links 90, thereby constraining the links 36, 36a connected thereto to adopt a corresponding angle to provide a fixed distance between adjacent spools 44. By adjusting the height of the cam members 98, 100 above the plane of the top surface of the spool shaft rail 26, the angle of the links 90 and hence the links 34, 34a can be adjusted, and hence the spacing between adjacent spools adusted.

It will be seen in the embodiment described, that the cam member 100 is spaced further from the plane of the flange 30 of the spool shaft rail 26 than is the cam member 98, and hence the spacing between the spools in the region below the cam member 100 is greater than that in the region below the cam member 98. Therefore articles which are graded and enter the conveyor 120 are smaller articles than those which are graded beneath the cam 100 and enter the conveyor 122.

As can be seen from the left-hand side of Figure 1, as a link 90 approaches the cam surface it is extending substantially vertically and engages an upwardly inclined guide part 128 of the cam member 98 to guide the links 190 so that they can conform to the cam member proper. The cam connecting link 118 likewise guides the cam follower 96 over the region between adjacent cam members 98, 100. At the forward end of the cam member 100 is provided an upwardly inclined guide part 130 which permits of controlled return of links 94 to a vertical position. In order to support the chain in the region between engagement of a spool shaft carrier with the spool shaft rail 30, and with the drive drum 38, a guide surface 132 is provided which is engaged by the largest diameter parts of a spool 44.

In order to adjust the size of the grading apertures 46, the shafts 108 are rotated to raise or lower their associated cam member 98, 100 to permit of adjustment of the angle adopted by the links 90 and hence of the angle adopted by the links 34 and hence of the spacing between adjacent spools.

As best shown in Figure 4, the grading apertures 46 can be adjusted between a minimum size shown in Figure 4a, and a larger size shown in Figure 4b in which the included angle between the links 34 and 36 is greater than that shown in Figure 4a.

In all cases, the size of the apertures 46 are essentially of square configuration which is a preferred grading aperture configuration for certain applications, such as the grading of potatoes since this is the preferred configuration by the Potato Marketing Board.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A grading apparatus for grading articles comprising a grading surface comprising a plurality of spools each having a longitudinal axis which extends transversely of the surface, the spools being spaced apart longitudinally of the surface and being of a configuration so as to provide a plurality of grading apertures between adjacent pairs of spools and adjustable means to vary the distance between adjacent spools in a direction longitudinally of the grading surface.

2. A grading apparatus for grading articles comprising a chain conveyor providing a grading surface comprising a plurality of spools each having a longitudinal axis which extends transversely of the surface and being of a configuration so as to provide a plurality of grading apertures between adjacent pairs of spools, the spools being spaced apart longitudinally of the surface and extending between spaced parallel chains, each of which comprise at least two links between each pair of adjacent spools, the mutual angular orientation of the links being variable, to vary the spacing between the spools, by means of a cam follower fixed relative to one of the links and engageable with a cam surface which is adjustable to vary the distance between the cam surface and the plane of the grading surface thereby permitting adjustment of the spacing of the spools in a direction longitu dinally of the grading surface.

3. A grading apparatus according to claim 1 or claim 2 wherein the spools are caused to rotate as a result of longitudinal movement of the spools along the grading surface.

4. A grading apparatus according to any one of claims 1 to 3 wherein the apertures defined between the spools are of generally square configuration with the full extent of at least two sides of the square being provided by surface parts of the spools.

5. A grading apparatus according to any one of the preceding claims wherein the spools are carried on shafts which are supported by spool shaft rails.

6. A grading apparatus according to claim 5 wherein the spool shaft has spool shaft carriers which are engaged with the rail.

7. A grading apparatus according to claim 6 wherein the spool shaft carriers are rotatable relative to the shaft.

8. A grading apparatus according to any one of claims 5 to 7 when dependent upon claim 1, wherein the spool shafts are interconnected in a continuous chain by links.

9. A grading apparatus according to any one of claims 5 to 7 when dependent upon claim 2, wherein the spool shafts are interconnected in said chain by links.

10. A grading apparatus according to claim 8 or claim 9 wherein the chain is engaged around at least two rotatable driving members.

11. A grading apparatus according to claim 10 wherein one of the two driving sprockets is located at one end of the apparatus, a forward end, and the other of the two is located at the opposite end of the apparatus, a rearward end.

12. A grading apparatus according to claim 11 wherein the location of the drums is such that the chain of spools move from the rearward end to the forward end of the apparatus on the top run of the chain.

13. A grading apparatus according to any one of the preceding claims wherein each spool com prises a first frusto-conical part and a second frusto-conical part of generally larger diameter with an intermediate frusto-conical part therebetween.

14. A grading apparatus according to claim 13 wherein the surface of the intermediate frusto-conical part and the surface of the second frusto-conical part cooperate with corresponding surfaces of an adjacent spool to define a grading aperture therebetween.

15. A grading apparatus according to claim 14 wherein the region of join between the frusto-coni cal parts is of smooth curved configuration.

16. A grading apparatus according to any one of the preceding claims wherein the spools com prise spool sections.

17. A grading apparatus according to claim 16 wherein each spool section is made as a moulding in a suitable material.

18. A grading apparatus according to claim 17 wherein the material is rubber.

19. A grading apparatus according to claim 18 wherein each spool section is provided with a central passage in which is received the spool shaft.

20. A grading apparatus according to claim 19 wherein the central passage and spool shaft is of a substantially square cross-section.

21. A grading apparatus according to claim 19 or claim 20 wherein one end of the spool shaft is fixed to an associated spool shaft carrier.

22. A grading apparatus according to claim 21 wherein the spool shaft carrier has a circular crosssection surface portion which runs on the spool shaft rail.

23. A grading apparatus according to claim 8 or any one of claims 10 to 22 dependent upon claim 8, wherein said links comprise a plurality of first links and a plurality of second links, the first links carrying and being pivotally connected to said support shafts and being pivotally connected to the second links about the axis of pivotal connection to the spool shafts, the chain also comprising a plurality of first and second intermediate links, each first link being pivotally connected to a second intermediate link and each second link being pivotally connected to a first intermediate link and each adjacent pair of first and second intermediate links being pivotally connected together, each first link and each first intermediate link having a cam follower fixed relative thereto and engageable with a cam surface which is adjustable to vary the distance between the cam surface and the plane of the grading surface thereby permitting adjustment of the spacing of the spools in a direction longitudinally of the grading surface.

24. A grading apparatus according to claim 9 or any one of claims 10 to 22 when dependent upon claim 9, wherein said links comprise a plurality of first links and a plurality of second links, the first links being pivotally connected to and carrying said spool shafts and being pivotally connected to the second links about the axis of pivotal connection to the spool shafts, the chain also comprising a plurality of first and second intermediate links, each first link being pivotally connected to a second intermediate link and each second link being pivotally connected to a first intermediate link and each adjacent pair of first and second intermediate links being pivotally connected together, each first link and each first intermediate link having said cam follower fixed relative thereto which is engageable with said cam surface.

25. A grading apparatus according to claim 23 or claim 24 wherein the first chain links comprise a pair of spaced parallel members each having an aperture at one end thereof.

26. A grading apparatus according to claim 25 wherein a bearing, carried on the spool shaft, is received in the apertures,

27. A grading apparatus according to claim 24 wherein the second chain links comprise a pair of spaced parallel members, the bearing being received in apertures provided at one end of said pair of spaced parallel members.

28. A grading apparatus according to claim 23, or any one of claims 25 to 27 when dependent upon claim 23, wherein the cam follower is provided on an element extending laterally from each of said first links and each of said first intermediate links.

29. A grading apparatus according to claim 2 or any one of claims 3 to 28 when dependent upon claim 2, or claim 23, or any one of claims 25 to 28 when dependent upon claim 23, wherein the cam followers are in engagement with first and second cam surfaces.

30. A grading apparatus according to claim 29 wherein each cam surface is provided by a surface of a cam member of inverted T cross-section.

31. A grading apparatus according to claim 29 or claim 30 when dependent upon claim 10 or when dependent upon any one of claims 11 to 28 when dependent upon claim 10, wherein the cam follower is in engagement with a first cam surface at the rearward end of the apparatus and in engagement with a second cam surface at the front end of the apparatus.

32. A grading apparatus according to claim 31 wherein a surface of a cam link is provided between the first and second cam surfaces, said cam link being pivotally connected to the first cam member and pivotally and slideably connected to the second cam member, to permit of independent adjustment of the height of said cam members.

33. A grading apparatus according to claim 31 or claim 32 wherein the angle of relative inclination of adjacent links is adjustable by adjusting the height of the first and second cam surfaces thereby allowing adjustment of the spacing between adjacent spools.

34. A grading apparatus according to any one of the preceding claims wherein conveyors are provided beneath the grading surface for articles which pass through the grading apertures.

35. A grading apparatus according to claim 34 when dependent upon claim 12, or when dependent upon any one of claims 13 to 33 when dependent upon claim 12, wherein an exit chute is provided at the forward end of the apparatus to discharge articles which have not passed through the grading apertures, and at the rearward end of the apparatus, is provided with a feed chute down which an article to be graded is fed onto the grading surface.

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

36. A grading apparatus substantially as hereinbefore described with reference to the accompanying drawings.