GB2236267A - Grading web and apparatus - Google Patents

Abstract

A grading web and apparatus for grading articles such as vegetables or fruit comprises an endless web which consists of a meshwork defining a plurality of apertures (2) of quasi-circular shape, dimensions of which dictate the size and shape of the articles which may pass therethrough when the web in use is agitated. The apertures are preferably hexagonal, as shown, but may be of any polygonal shape having at least six sides and generally circular overall. The meshwork may comprise individual steel elements (5) clipped (6) together. The meshwork is formed into an endless belt passing over spaced rollers. The upper run is caused to vibrate up and down locally by passage over raised rollers. <IMAGE>

Description

Title: Grading Web and apparatus.

Description of Invention This invention relates to a grading web and apparatus for grading articles, for example, vegetables, fruit or the like. A grading apparatus is known which comprises a moving endless steel web which provides a conveying surface and comprises a meshwork which defines a number of square apertures through which articles can pass provided that their dimensions are smaller than the corresponding dimensions of the apertures defined by the meshwork. The web is agitated as it is moved to separate and distribute the articles over the web thus ensuring that the articles have an opportunity to contact the web and to pass through the apertures. Any articles which do not pass through the apertures are discharged at the end of the conveying surface.

An object of the invention is to provide a new and improved grading web and apparatus.

According to one aspect of the invention we provide a grading web for grading articles comprising a meshwork defining a plurality of apertures of quasi-circular shape as hereindefined.

Each aperature may be polygonal and have at least six sides.

The web may have a uniform distribution of apertures throughout its surface.

Alternatively, the web may have a non-uniform distribution of apertures throughout its surface, the apertures increasing in dimension from a first location at which articles to be graded are loaded onto the web towards a second location towards which articles are conveyed along the web.

The web may be flexible.

The web may be comprised of articles linked together to permit of articulation of the web about a plurality of discrete axes.

Each axis of articulation may lie through at least two junctions at which the elements are linked together.

The elements may each comprise a filament which is linked to other filaments at junctions spaced along the length of each filament.

The web may be endless and said axes of articulation may extend transversely of the web.

According to another aspect of the invention we provide an apparatus for grading articles comprising a grading web according to the first aspect of the invention.

The apparatus may include an agitating means to agitate the web.

The agitating means may agitate the web in a direction which has a component which is perpendicular to a grading surface defined by the web.

The web may be looped around a pair of spaced guide members and driven to provide an upper run and a lower run, the upper run of the web providing a conveying and grading surface and the lower run providing a return run of the web.

The web may be flexible about axes which are perpendicular to the direction of advance of the web.

The agitating means may include an agitating surface with which at least a part of the web is engaged to cause the web to oscillate in a direction having a component perpendicular to the grading surface of the web.

The agitating means may be comprised of a plurality of rollers.

The agitating surface may be provided at a fixed location but define a path so that the web is caused to oscillate as it passes along the agitating means.

Filaments providing at least two edges of each aperture may contact the agitating means.

The filaments where they contact the agitating means may be disposed obliquely thereto.

The filaments may be linked together by sleeves or clips.

A web which has square apertures suffers from the disadvantage that the articles are graded only across the two orthogonal dimensions of the square. The present invention overcomes the problem by ensuring that articles are graded across at least threedimensions perpendicular to sides of an aperture.

Moreover, when the articles to be graded are generally rounded the corner areas of each square aperture comprise an essentially redundant area in terms of utility in grading. The present invention reduces the size of the redundant area.

Where the web is agitated by contact of parts of the web with an agitator means, then when the web provides square apertures the amount of meshwork contacting the agitating means is small which can lead to fouling of the mechanism causing damage to the web.

The present invention enables the above mentioned disadvantage to be overcome or to be reduced.

Embodiments of this invention will now be described by way of example with reference to the accompanying drawings wherein, FIGURE 1 if a diagrammatic plan view of part of a grading web embodying the invention; FIGURE 2 is a diagrammatic side view of a grading apparatus embodying the invention, and FIGURE 3 is a diagrammatic plan view of part of another grading web embodying the invention.

Referring to the drawings a grading web 1 comprises a meshwork in which apertures 2 are defined by the meshwork. Each aperture is substantially uniform in terms of dimension and shape and is generally in the form of a regular hexagon. Consequently each aperture 2 is defined by at least three dimensions indicated at 3 which dimensions are substantially in the same plane which plane includes an edge 4 of the aperture.

The web is flexible and comprises a number of filaments 5 which are linked together so as to permit of articulation of the web about a number of separate substantially parallel axes. the filaments 5 arr- li nk together at spaced positions by means of clips 6 of generally tubular shape having a longitudinally extending slot through which the filaments can pass to assemble the web and which is then closed or reduced in width to link the filaments together.

The web 1 is incorporated in a grading apparatus by being formed into an endless loop which is looped around a pair of spaced rotatable guide members 11 at least one of which is driven by a motor 12. Between the guide members an upper run 13 of the web provides a conveying and grading surface and a trough 14 is provided therebeneath to receive articles which have passed through the web. Also disposed between the upper run 13 and a lower run 15 is an agitating means 16 comprising a plurality of agitator rollers which are provided to act on the upper run of the web to cause up and down movement of the web as it passes over the rollers. The region of the web engaged by the rollers is indicated at 17 in Figure 1.Relatively long parts of the filaments 5 are in contact with the rollers of the agitating means 16 since the sides of the hexagon shaped apertures are at 600 and hence the side portions of the filaments 5 are in contact with the agitator rollers longer, thus increasing the area they run on and thereby greatly reducing the possibility of damage and also increasing web life.

By virtue of providing hexagonal apertures the stringency of grading is improved compared with webs which define square apertures which only grade articles across two orthogonal dimensions whereas the hexagonal apertures described hereinbefore grade articles in the above described three dimensions. In addition, the provision of hexagonal apertures reduces the dead areas caused by the corners of the apertures so that in the present example the total dead area of the web is approximately 9% which is to be compared with about 21% which is encountered when square apertures are used.

Although hexagonal apertures have been described hereinbefore, if desired other shapes may be provided which are quasi-circular, that is to say, apertures which are polygonal in shape but having at least six sides or which are circular or substantially circular. Hexagonal apertures are preferred because they can conveniently be linked together by providing the clips 6 described hereinbefore in between adjacent sides of the hexagon but a circular configuration can be provided, as shown in Figure 3, by utilizing clips 6a which can accommodate a curved part of the filaments 5a and forming the clips to a corresponding part-circular shape.

Although the invention has been described hereinbefore in connection with an endless web which defines a conveying and grading surface which is preferably oscillated in a direction normal to the surface by the agitating means 16. If desired, the web may be incorporated in other forms of grading apparatus, for example, where the web is not in the form of a continuous loop but is of a discrete length and is, for example, inclined to cause articles to be conveyed along the surface and/or which may be oscillated in a direction having a component which extends lengthwise of the surface or crosswise.

For example, the web may be flexible as described hereinbefore and subjected to a wave-like deformation so as to provide a plurility of waves which travel lengthwise along the web, the web itself being translationally fixed, unlike the previously described apparatus where the web is translationally movable in that it is in the form of a endless rotatable belt.

Further alternatively, the web may be rigid .InA -'rnted for oscillation as a whole.

In the example illustrated the apertures in the web are of uniform configuration and distribution throughout the whole surface of the web. However, in cases where the web is translationally fixed and articles are caused to move along the web, either by virtue of deforming the web locally such as to provide a travelling wave, or by oscillating the web as a whole, the apertures may be of varying size, for example, of increasing size from an entry end of the web where articles to be graded are loaded upon the web towards an exit end towards which the articles are conveyed.

Also, if desired the web may, instead of defining a planar grading surface, define a non-planar surface of any suitable configuration.

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, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (22)

CLAIMS:

1. A grading web for grading articles comprising a meshwork defining a plurality of apertures of quasicircular shape, as herein defined.

2. A grading web according to Claim 1 in which each aperture is polygonal and has at least six sides.

3. A grading web according to Claim 1 or Claim 2 which has a uniform distribution of apertures throughout its surface.

4. A grading web according to any one of the preceding claims which is flexible.

5. A grading web according to any one of the preceding claims which comprises elements linked together to permit of articulation of the web about a plurality of discrete axes.

6. A grading web according to Claim 5 in which each axis of articulation lies through at least two junctions at which the elements are linked together.

7. A grading web according to Claim 5 or Claim 6 in which the elements each comprise a filament which is linked to other filaments at junctions which are spaced along the length of each filament.

8. A grading web according to any one of Claims 5 to 7 in which the web is endless and said axes of articulation extend transversely of the web.

9. A grading web substantially as hereinbefore described with reference to the accompanying drawings.

10. An apparatus for grading articles comprising a grading web according to any one of Claims 1 to 9.

11. An apparatus according to Claim 10 which includes an agitating means to agitate the web.

12. An apparatus according to Claim 11 in which the agitating means agitates the web in a direction which has a component which is perpendicular to a grading surface defined by the web.

13. An apparatus according to any one of Claims 10 to 12 in which the web is looped around a pair of spaced guide members and driven to provide an upper run and a lower run, the upper run of the web providing a conveying and a grading surface and the lower run providing a return run of the web.

14. An apparatus according to any one of Claims 10 to 13 in which the web is flexible about axes which are perpendicular to a direction of advance of the web.

15. An apparatus according to Claim 11 or Claim 12 in which the agitating means includes an agitating surface with which at least a part of the web is engaged to cause the web to oscillate in a direction having a component perpendicular to the grading surface of the web.

16. An apparatus according to any one of Claims 11, 12 or 15 in which the agitating means comprises a plurality of rollers.

17. An apparatus according to Claim 15 in which the agitating surface is provided at a fixed location but defines a path so that the web is caused to oscillate as it passes along the agitating means.

18. An apparatus according to any one of Claims 11 to 17 in which filaments providing at least two edges of each aperture contact the agitating means.

19. An apparatus according to Claim 18 in which the filaments, where they contact the agitating means, are disposed obliquely thereto.

20. An apparatus according to any one of Claims 10 to 19, when appendant to Claim 7 s wh- the filaments are linked together by sleeves or clips.

21. An apparatus substantially as hereinbefore described with reference to the accompanying drawings.

22. Any novel feature or novel combination of features disclosed herein.