GB2432097A

GB2432097A - Bulb or root crop separators

Info

Publication number: GB2432097A
Application number: GB0522930A
Authority: GB
Inventors: Derek Scott; Matthew Shaw
Original assignee: SCOTTS IND Ltd
Current assignee: SCOTTS INDUSTRIES LTD
Priority date: 2005-11-10
Filing date: 2005-11-10
Publication date: 2007-05-16
Anticipated expiration: 2025-11-10
Also published as: GB0522930D0; GB2432097B

Abstract

Apparatus for separating a bulb or root crop from debris, comprises a plurality of substantially parallel primary rollers 5 disposed generally transverse to a feed direction of a root crop from an entry end of the apparatus to a discharge end, said primary rollers being fluted 6 along their length, a plurality of secondary rollers (not shown) disposed such that a secondary roller is located adjacent a respective primary roller, drive means for rotating said primary and secondary rollers in the same direction about their respective axes, and wherein at least said primary rollers are adapted for resilient deformation radially of their respective axes whereby to allow large and/or solid debris to pass therebetween. Also claimed is a method of separating a bulb or root from debris.

Description

BULB OR ROOT CROP SEPARATORS

Field of the Invention

The present invention is concerned with bulb or root crop separating ap-paratus and, more particularly, separating apparatus for separating a harvested bulb or root crop from haulm, stones, clods and other debris. The apparatus is generally suited for separating any type of bulb or root crop of any size or shape, with or without foliage and/or herbage. The separator is particularly suited to separating potatoes, but is not necessarily limited to potatoes.

Background to the Invention

There is a continuing demand for apparatus for harvesting crops effi-ciently and cleanly. The more debris that can be separated from the crop in the early stages of harvested crop preparation, the easier the next stages of crop preparation.

One problem with existing apparatus is the tendency for the root crops to become damaged in the process of separating the desired crop from the unde-sired debris. An objective of the apparatus is therefore to improve separation whilst minimising damage to the crop. One type of known harvesting apparatus includes a separator employing a plurality of spaced rollers and a mechanism for encouraging the debris to fall between the rollers, allowing the crop to con- tinue along or over the rollers for collection at the end of the roller run. How-ever, a problem with this kind of apparatus is the tendency of large clods and/or stones to become wedged between the rollers and potentially jam the mecha-nism.

Previous attempts at crop separation have included the use of a hydrau-lic roller drive with an automatic bleed valve to release pressure when a jam oc-curs and thereby minimise damage to the rollers and the drive. Rollers can be arranged transversely across the general flow of the crop over the apparatus.

In the case of transverse rollers, as in US 5775435 and US 5197550 for exam-ple, the rollers are generally arranged in counter-rotating pairs. However, in GB 1182760 scrolled rollers are arranged in pairs, one either side of an inter-mediate smooth roller, all of the rollers rotating in the same direction. The smooth rollers are rubber-faced, while the scrolled rollers are of steel. The ap-paratus is intended for cleaning root crops. US 5197550 is similar in that it uses spiral "grabrolls" made of steel with spiral steel bars but the smooth intermedi-ate rollers rotate in the opposite direction to the scrolled rollers. Finally, GB 2239157 discloses spiral rubber rollers adjacent to plain rollers. A particular type of separator employing counter-rotating, transverse pairs of rollers, such as in GB 2247817, operates in collaboration with a compartmented conveyor hav- ing pockets to locate and guide individual root crops from an entry to a dis-charge end across the tops of the rollers.

In the case of rollers arranged generally parallel to the crop flow, they are invariably provided with a spiral screw formation to drive the crop from one end to the other. In one such case (WO 01/33938), the rollers are resiliently mounted to accommodate an element of lateral movement and the rollers themselves are segmented along their length to permit an element of radial movement, whereby larger stones and clods can be allowed to pass between the rollers.

Despite such activity in the art, there is still a demand for improved appa- ratus that enables crops to be separated from debris, some of which is poten-tially damaging to the apparatus, without damaging the crop itself.

Summary of the Invention

In accordance with a first aspect of the present invention, apparatus for separating a root crop from debris comprises a plurality of substantially parallel primary rollers disposed generally transverse to a feed direction of a root crop from an entry end of the apparatus to a discharge end, said primary rollers be-ing fluted along their length, a plurality of secondary rollers disposed such that a secondary roller is located adjacent a respective primary roller, drive means for rotating said primary and secondary rollers in the same direction about their re-spective axes, and wherein at least said primary rollers are adapted for resilient deformation radially of their respective axes whereby to allow large and/or solid debris to pass therebetween.

In accordance with a second aspect, the invention provides a method of separating a root crop from debris, comprising passing a mixture of said root crop and debris over a plurality of substantially parallel primary rollers disposed generally transverse to a feed direction of said root crop and debris from an en-try end to a discharge end, said primary rollers being fluted along their length, said primary rollers cooperating with a plurality of secondary rollers disposed such that a secondary roller is located adjacent a respective primary roller, and rotating said primary and secondary rollers in the same direction about their re-spective axes, and wherein at least said primary rollers are adapted for resilient deformation radially of their respective axes whereby to allow large and/or solid debris to pass therebetween.

The primary rollers are preferably each formed with flutes on their pe-ripheral surface.

The flutes may follow a spiral path with changes in direction along the length thereof. This may be achieved by the use of shorter alternate roller sec- tions of opposite flute direction, mounted on a common shaft to constitute a sin-gle primary roller.

Preferably, there are at least six equally-spaced flutes around the pe-riphery of each primary roller.

The flutes may be of rubber and formed on a sleeve attached to a roller core. Alternatively, the primary rollers may be of rubber and formed integrally with the flutes.

The secondary rollers preferably have a substantially smooth outer sur-face. They may be adjustably mounted relative to the primary rollers, and are preferably spaced from the primary rollers, in use, such that the flutes on the primary roller do not contact the secondary roller, or are not caused to deflect or distort by such contact if it does occur. However, the secondary roller is pref-erably able to deflect to allow larger stones and the like to pass between the primary and secondary rollers. This may be achieved by providing a tension spring between a hanger for the secondary roller and the main frame of the ap-paratus.

The primary rollers are preferably mounted on a first frame means and the secondary rollers are mounted on a second frame means movable relative to the first frame means.

The first frame means may comprise an upper frame member mounted for vertical movement relative to said first frame means and to which upper ends of a plurality of support arms are pivotally mounted, said support arms having bearings intermediate said upper ends and lower ends thereof on which the secondary rollers are rotationally mounted.

Preferably, first screw-threaded adjustment means are provided between the first and second frame means for vertical adjustment of the secondary roll-ers.

The second frame means may comprise a lower frame member mounted for horizontal movement relative to said first frame means and second screw-threaded adjustment means may be provided between the first and second frame means for horizontal adjustment of the secondary rollers.

In such a construction, screw-threaded stop means may be provided on said lower frame member for engagement with lower ends of said support arms, whereby to provide a predetermined minimum horizontal spacing between the primary and secondary rollers.

The lower end of said support arms are preferably resiliently biased against said stop means.

Making all the rollers rotate in the same direction minimises the risk of the flutes on the rollers trying to force the root crop between the rollers. Be-cause the secondary rollers rotate in the same direction, they tend to carry the root crop away from the flutes, feeding them along the apparatus towards the discharge end. By contrast, the clods will tend to be broken up by the flutes, if not on the first pair of rollers then successively along the apparatus. Similarly, stones may be fed towards the discharge end but are more likely simply to drop (with assistance from the flutes) through the gaps between the rollers.

The primary purpose of the present invention is secondary cleaning in the packing shed but it is conceivable that it could be used for harvesting, in which case it could form part of a harvester and would be located intermediate a root crop lifting end and a collecting end of the harvester. Power for the crop separator can be taken from a power take-off provided in a tractor unit.

Brief Description of the Drawings

The present invention will now be described with reference to the follow-ing drawings, in which: Figure 1 is a part skeleton drawing showing the essential components of the apparatus; Figure 2 shows a first construction of primary roller for use in the appara-tus of Figure 1; and Figure 3 shows a second construction of primary roller for use in the ap-paratus.

Detailed Description of the Illustrated Embodiments Referring to Figure 1, a separating table for cleaning bulb or root crops (hereinafter referred to simply as root crops) and separating them from accom-panying debris, stones, clods, haulm and other unwanted vegetation, is formed by a pair of side frames 1, 2 and a roller assembly supported between them.

The crop to be separated enters from the left and travels across the tops of the roller assembly to a discharge end at the right. The apparatus is ideally suited for potatoes but it may be used for any type of bulb or root crop of any size or shape with or without foliage or herbage.

The roller assembly comprises a set of substantially parallel primary roll-ers 3 mounted at each end in bearings 4 fixed to the respective frames 1, 2.

The rollers 3 are provided with flutes 5 formed on their outer surface as a part spiral but it should be noted that the spiral is not continuous in that it changes direction several times along the length of the roller. Preferably there are at least six flutes per roller. The flutes are deformable. A convenient material for the flutes is rubber, which is sufficiently "solid" but deformable to cope with hard objects, such as stones and rocks, brought in with the crop, and large hard clods of soil or clay.

The effective radius of the primary rollers can vary, as will be explained later, in order to allow passage of particularly large and/or solid items of debris.

The primary rollers are all rotated in the same direction as indicated by the arrows through a drive means (not illustrated) coupled to all of the rollers.

An arrangement of pulleys, gear wheels and/or chain drives may be used for this purpose, as is well-known in the art. It is preferable for the drive means to be variable in speed to accommodate varying crop sizes and the nature of the accompanying debris.

The primary rollers are spaced a predetermined distance apart, sufficient for debris to fall through the space between them to a lower area where they can be removed, preferably by a conveyor. This may be of any known kind.

The primary rollers co-operate with secondary rollers (not shown). These are mounted at their ends in bearings 6 carried by sub-frames 7 mounted on the side frames 1, 2. As shown in Figure 1, slots 8 in the sub-frame are engaged by spigots 9 fixed to the side frames to constrain relative movement. The verti-cal position of the sub-frames can be adjusted by means of the screw-threaded members 10 coupling the sub-frames to the side frames 1, 2.

The sub-frames 7 carry support arms 11 mounted at their upper ends with bearings 12 to provide them with limited pivotal movement relative to the sub-frames. The lower ends of the support arms 11 are formed with fingers 13.

Biasing springs 14 are attached at one end to the fingers 13. The lower ends of the support arms 11 just above the fingers 13 engage another set of screw-threaded adjusters 15 mounted on a slider 16 mounted on spigots 17 on the side frames 1, 2. The other ends of the springs 14 are attached to fixed points on the slider. A further screw-threaded adjuster 18 is used to position the slider 16 in the fore-aft direction relative to the crop flow.

The horizontal position of the secondary rollers along the length of the separator can therefore be adjusted by means of the screw-threaded adjuster 18 and the vertical position by the adjusters 10. The springs 14 and adjusters 15 co-operate to provide a stop position, as will shortly be explained. The over-all position of the secondary rollers relative to the primary rollers 3 can thus be set by suitable adjustment of the vertical and horizontal adjusters 10, 18.

The secondary rollers are also arranged to be rotated in the same direc-tion as one another and in the same direction as the primary rollers 3. The speed of rotation of the secondary rollers can be adjusted to accommodate varying crop sizes and the nature of the accompanying debris.

Under normal use, the crop-plus-debris enters from the left and is trans-ported along the tops of the primary rollers 3, being passed from one to the next, through the action of the flutes. Small items of debris can fall through the gaps between the primary rollers 3. The flutes 5, being of rubber and therefore deformable, cause larger items of debris, such as clods, stones and the like, to be squeezed through the gaps. At the same time, the "scrubbing" action of the flutes rotating in the same direction relative to the crop, cleans surface soil from the crop as it passes over the succession of parallel rollers, aided by the secon- dary rollers. However, when a large/solid obstacle is encountered by the roll-ers, not only can the flutes deform, but also the body of the rollers themselves can deform, as will be described below. In addition, the co-operation of the springs 14 and adjusters 15 enable individual secondary rollers to move fore and aft to increase the gap between the primary and secondary rollers tempo-rarily to allow passage of the large item.

Figures 2 and 3 show in more detail preferred constructions for the pri-mary rollers and the flutes. As shown in Figure 2, the roller consists of a square-section shaft 20 supporting a core 21 formed with slots 22, 23, 24 and an outer sleeve 25 of rubber formed with flutes 26 corresponding to the flutes 6 in Figure 1. In this example, the flutes spiral along the length of the roller but change direction several times to cause the root crop to be vibrated along its path towards the discharge end of the table, whereby to shake off surface soil and dirt. The slots provide a degree of radial resilience to the rollers to accom-modate the passage of solid debris between the rollers.

In Figure 3, the construction is similar to that in Figure 2 except that the whole of the roller body 30 is made in one piece integrally with slots 31, 32, 33 and flutes 34. The slots are larger and occupy more of the cross-section of the roller, thereby giving even more resilience to the roller. The flutes are designed to be shallow and flexible enough to bend under the force of solid debris but sufficiently strong to transport the root crop to the discharge end of the table.

The flutes may be discontinuous and formed of a plurality of short lengths instead of a continuous raised edge. In either construction, the slots and the ability of the flutes to deform, means that the effective radius of the rollers is variable under load. The effect is that the root crop is handled relatively gently but with a surface scrubbing action, whereas debris is allowed to fall between the gaps. In the case of large and/or solid debris, the rollers "flex" to allow pas-sage of the debris between them but without damaging the rollers or the flutes.

The combination of a large number of deformable flutes of small height, and rotation in the same direction for all the rollers, so that the root crop is se-lectively fed along the cleaning bed, with the result that there is a smaller risk of damage to the root crops, produces novel and unexpected advantages in terms of performance and efficiency not previously experienced in the art.

Claims

Claims 1. Apparatus for separating a bulb or root crop from debris,

compris- ing a plurality of substantially parallel primary rollers disposed generally trans-verse to a feed direction of a root crop from an entry end of the apparatus to a discharge end, said primary rollers being fluted along their length, a plurality of secondary rollers disposed such that a secondary roller is located adjacent a respective primary roller, drive means for rotating said primary and secondary rollers in the same direction about their respective axes, and wherein at least said primary rollers are adapted for resilient deformation radially of their respec-tive axes whereby to allow large and/or solid debris to pass therebetween.

2. Apparatus as claimed in Claim 1, wherein the primary rollers are each formed with flutes on their peripheral surface.

3. Apparatus as claimed in Claim 2, wherein the flutes follow a spiral path with changes in direction along the length thereof.

4. Apparatus as claimed in Claim 2, wherein the flutes are of rubber and are formed on sleeve attached to a roller core.

5. Apparatus as claimed in Claim 2, wherein the primary rollers are of rubber and are formed with integrally the flutes.

6. Apparatus according to any of Claims 2 to 5, wherein each pri-mary roller carries at least six equally-spaced flutes therearound.

7. Apparatus as claimed in any of the preceding claims, wherein the secondary rollers have a substantially smooth outer surface.

8. Apparatus as claimed in any of the preceding claims, wherein the secondary rollers are adjustably mounted relative to the primary rollers.

9. Apparatus as claimed in Claim 8, wherein the primary rollers are mounted on a first frame means and the secondary rollers are mounted on a second frame means movable relative to the first frame means.

10. Apparatus as claimed in Claim 9, wherein the first frame means comprises an upper frame member mounted for vertical movement relative to said first frame means and to which upper ends of a plurality of support arms are pivotally mounted, said support arms having bearings intermediate said up-per ends and lower ends thereof on which the secondary rollers are rotationally mounted.

11. Apparatus as claimed in Claim 10, wherein first screw-threaded adjustment means are provided between the first and second frame means for vertical adjustment of the secondary rollers.

12. Apparatus as claimed in Claim 9, wherein said second frame means comprises a lower frame member mounted for horizontal movement relative to said first frame means and second screw-threaded adjustment means are provided between the first and second frame means for horizontal adjustment of the secondary rollers.

13. Apparatus as claimed in Claim 12, wherein screw-threaded stop means are provided on said lower frame member for engagement with lower ends of said support arms, whereby to provide a predetermined minimum hori-zontal spacing between the primary and secondary rollers.

14. Apparatus as claimed in Claim 13, wherein said lower end of said support arms are resiliently biased against said stop means.

15. A method of separating a bulb or root crop from debris, comprising passing a mixture of said root crop and debris over a plurality of substantially parallel primary rollers disposed generally transverse to a feed direction of said root crop and debris from an entry end to a discharge end, said primary rollers being fluted along their length, said primary rollers co-operating with a plurality of secondary rollers disposed such that a secondary roller is located adjacent a respective primary roller, and rotating said primary and secondary rollers in the same direction about their respective axes, and wherein at least said primary rollers are adapted for resilient deformation radially of their respective axes whereby to allow large and/or solid debris to pass therebetween.

16. Apparatus for separating a bulb or root crop from debris, substan-tially as described with reference to, and/or as shown in, the drawings.