GB1566958A - Grading of bulbs or tubers - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO THE GRADING OF BULBS OR TUBERS (71) I, JOHANNES CHRISTIANUS OVERVELD of 115 Moerkantlaan, Essen 2190, Belgium, of Dutch nationality, do hereby declare the invention, for which I pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a grading device for sizing bulbs or tubers, particularly potatoes and onions.

The invention has for its object to provide a grading machine of high capacity, capable of treating the product to be sorted with minimum damage.

According to the present invention there is provided a device for grading to size bulbs or tubers, particularly potatoes and onions, comprising a first group of parallel, rod shaped elements spaced apart by a distance exceeding the size of the crop, a second group of parallel rod shaped elements spaced apart by the same distance, conveying means conveying said elements of the first and second group simultaneously the elements of said second group being freely movable with respect to said conveying means transverse to the direction of transport and towards and away from the elements of the first group and guide means spaced away from the conveying means an increasing distance in the direction of transport of said conveying means whereby to guide said elements of the second group to predetermined positions spaced away successively further from said elements of the first group.

Grading to size is determined by the distance between a rod-shaped element of the first group and an element of the second group. This distance depends upon the distance between these co-operating elements of the two groups. Since the guide means diverges from the conveying direction the distance between two related elements becomes larger.

In a further development of the invention at least the elements of the first and second group are connected with endless conveyor means. In this manner a continuous conveyance is obtained, the end of the return run being the beginning of the grading process. The elements of the second group may be connected with their own conveyor, which is driven synchronously with the conveyor carrying the elements of the first group.

In a preferred embodiment, however, the elements of the second group are also carried along by the conveyor of the first group so that these elements of the second group are passed along a guide departing from the operative run. In this embodiment the elements of the two groups will move accurately in synchronysm, but the elements of the second group can move away from the elements of the first group transverse to the transport direction so that the distance between cooperating ones of the two groups of elements is enlarged, which determines the size of the product allowed to pass.

In order to avoid damage of the product, the invention suggests the covering of each element with an elastic sheath, which is preferably profiled so that radial ridges are formed, which assists the grading effect of the device.

Further features and advantages of the invention will become apparent from the following description of an embodiment with reference to the drawing, in which Figure 1 is a schematic side elevation of a preferred embodiment of the grader, Figure 2 is a side elevation of part of the operative run of the endless conveyor provided with the two groups of rod-shaped elements, Figure 3 is a sectional view taken on the line III-III in Figure 2, Figure 4 is a sectional view taken on the line IV-IV in Figure 3.

In the embodiment of the grader shown schematically in Figure 1 reference numeral 1 designates the endless conveyor formed by two parallel chains passed along four chain sprockets 2 each. Between the two parallel chains are arranged relatively parallel, rodshaped elements 3, which are arranged in two groups.

One group of rod-shaped elements 31 (see Figure 2) are rigidly secured to the conveyor chains 1 at the level of the hinges between the links 4 of the chain conveyor 1.

The other group of rod-shaped elements 32 are coupled through a bracket 5 with each link 4 of the chain. Each rod-shaped element 32 can move towards and away from the link owing to a slot-shaped hole in the bracket 5. The rod-shaped element 32 is thus carried along in the transport direction indicated by the arrow P1 in Figure 1 with the chain conveyor 1, but it is freely movable in a direction at right angles to the transport direction. Therefore the distance of the rod-shaped element 32 from the link 4 is variable and hence also from the rodshaped elements 31.

In this embodiment the distance between the elements 31 and 32 is determined by a guide 6 spaced stepwise from the chain 1 in the direction of transport. The guide 6 is formed by rod sections having a square cross-section and is arranged stepwise. The height of each guide rod is separately adjustable (see Figure 2). In order to obtain a correct guidance each rod-shaped element 32 is provided at each end with a wheel 7 rolling along the guide 6.

In a similar manner each rod-shaped element 31 is provided at each end with a wheel 8 rolling along a square-section, rod-shaped guide 9.

The grading device shown operates as follows.

One of the chain sprockets 2 is driven so that the upper or operative run of the chain conveyor 1 moves in the direction of the arrow P1. The chain conveyor 1 thus carries along the groups of rod-shaped elements 31 and 32 respectively. On the left-hand side of Figure 1 at 10 the products to be sorted, for example, potatoes are fed to arrive at the rod-shaped elements 3. Since the rodshaped elements 31 are spaced apart by a distance exceeding the maximum size of the products to be sorted, the products will arrive at the rod-shaped elements 32. These rod-shaped elements 32 together form the supporting surface. The rod-shaped elements 31 perform the transport in the direction of the arrow P1 and constitute together the transporting surface.According to the invention the transporting surface and the supporting surface are diverging, which is ensured in the embodiment shown by arranging the guide 6 in the direction of the arrow P1 progressively further away from the links 4 of the chain 1. During the conveyance to the right in Figure 1 initially small and progressively larger products will drop between the elements 31 and 32 in accordance with the varying distance between the guides 6 and the chain 1. For conducting away the graded product a delivery conveyor 11 is associated with each section of the guide 6, the direction of conveyance being considered to be normal to the plane of the drawing in Figure 1.

After the elements 31 and 32 are passed along the operative run of the conveyor, they are returned to the starting point at the feeding area 10, the elements 32 dropping by gravity in the slot in the bracket 5 in the direction of the link 4 of the conveying chain 1. At the feeding area 10 the elements 31 and 32 are automatically spaced apart by the correct distance.

In Figure 2 the shaded circles Al, A2 and A3 represent respectively products of small, medium and large sizes, the smallest product Al being allowed to pass when the element 32 is in the topmost position in the slot in the bracket 5; this element is indicated by a dot-and-dash line in Figure 2, which position has to be considered to be at the beginning of the operative run of the chain conveyor 1.

Each rod-shaped element 31 and 32 is coated with an elastic sheath 12 (see Figure 3), so that the product to be graded will be damaged as little as possible. The sheath is profiled so that radial ridges 13 and intermediate grooves 14 are formed.

The transition between the ridges 13 and the grooves 14 is preferably gradual, which can be ensured by a slanting surface. The whole sheath 12 may be simply constructed from a plurality of annular bodies 15 of suitable, elastic material (see Figure 4).

Each annular body comprises a circular, thick portion with a spacing piece of smaller diameter, the circumferential edge of the circular portion being bevelled.

The two extreme bodies on a rod-shaped element 31 have an end flange having an outer diameter exceeding that of the annular body. In this way the product is prevented from dropping down beside the transporting surface. The two extreme annular bodies on the rod-shaped element 32 are only half of the bodies 15.

It should be noted that the ridges 13 and the grooves 14 of the two relatively cooperating, rod-shaped elements 31 and 32 are located in the same radial plane so that a product A is each time retained between two adjacent ridges of the same element and ridges of the other element to be finally allowed to pass when the distance is sufficiently large. Practice has shown that such profiles yield the best results in sizing.

As a matter of course, other embodiments are possible within the scope of the invention. For example, the two groups of rod-shaped elements need not be driven by the same conveying means, since other conveyors may be individually used for each group. Moreover, a reciprocatory movement of the groups may be performed beneath the feeding area 10, so that an intermittent grading effect is obtained. The guides 6 may be constructed in a manner differing from the rod-shaped elements shown. For example, a channel-section rail may be employed so that the divergence of the two elements 31 and 32 can be compulsorily performed. The guide 6 may be continuous and the guide 9 may cause a stepwise elevation.

WHAT WE CLAIM IS: 1. A device for grading to size bulbs or tubers, particularly potatoes and onions, comprising a first group of parallel, rod shaped elements spaced apart by a distance exceeding the size of the crop, a second group of parallel rod shaped elements spaced apart by the same distance, conveying means conveying said elements of the first and second group simultaneously, the elements of said second group being freely movable with respect to said conveying means transverse to the direction of transport and towards and away from the elements of the first group, and guide means spaced away from the conveying means an increasing distance in the direction of transport of said conveying means whereby to guide said elements of the second group to predetermined positions spaced away successively further from said elements of the first grou 2.A device as claimed in claim 1 wherein each element of the second group has its ends movably mounted in a bracket connected to an endless conveyor by moving in an elongated hole extending normally to the direction of transport.

3. A device as claimed in claim 2, characterised in that the guide means is spaced stepwise from the conveyor means.

4. A device as claimed in claim 3, characterised in that each stepped portion of the guide means is adjustable with respect to the conveyor means.

5. A device as claimed in claim 3 or claim 4, characterised in that a delivery conveyor is arranged beneath each stepped portion of the guide means.

6. A device as claimed in any one of the preceding claims, characterised in that each element is covered with an elastic sheath.

7. A device as claimed in claim 6, characterised in that said sheath is profiled.

8. A device as claimed in claim 7, characterised in that the profile is formed by radial successive grooves and ridges.

9. A device as claimed in any one of claims 6 to 8, characterised in that the sheath is formed by a plurality of annular bodies separated by axial spacers of smaller diameter than the annular bodies.

10. A device as claimed in claim 9, characterised in that the circumferential edge of each annular body is bevelled on both sides.

11. A device as claimed in any preceding claim, characterised in that the two groups of elements are connected to a single conveyor chain.

12. A device for grading to size bulbs or tubers, substantially as described hereinbefore with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (12)

**WARNING** start of CLMS field may overlap end of DESC **. profiles yield the best results in sizing. As a matter of course, other embodiments are possible within the scope of the invention. For example, the two groups of rod-shaped elements need not be driven by the same conveying means, since other conveyors may be individually used for each group. Moreover, a reciprocatory movement of the groups may be performed beneath the feeding area 10, so that an intermittent grading effect is obtained. The guides 6 may be constructed in a manner differing from the rod-shaped elements shown. For example, a channel-section rail may be employed so that the divergence of the two elements 31 and 32 can be compulsorily performed. The guide 6 may be continuous and the guide 9 may cause a stepwise elevation. WHAT WE CLAIM IS:

1. A device for grading to size bulbs or tubers, particularly potatoes and onions, comprising a first group of parallel, rod shaped elements spaced apart by a distance exceeding the size of the crop, a second group of parallel rod shaped elements spaced apart by the same distance, conveying means conveying said elements of the first and second group simultaneously, the elements of said second group being freely movable with respect to said conveying means transverse to the direction of transport and towards and away from the elements of the first group, and guide means spaced away from the conveying means an increasing distance in the direction of transport of said conveying means whereby to guide said elements of the second group to predetermined positions spaced away successively further from said elements of the first grou

2.A device as claimed in claim 1 wherein each element of the second group has its ends movably mounted in a bracket connected to an endless conveyor by moving in an elongated hole extending normally to the direction of transport.

3. A device as claimed in claim 2, characterised in that the guide means is spaced stepwise from the conveyor means.

4. A device as claimed in claim 3, characterised in that each stepped portion of the guide means is adjustable with respect to the conveyor means.

5. A device as claimed in claim 3 or claim 4, characterised in that a delivery conveyor is arranged beneath each stepped portion of the guide means.

6. A device as claimed in any one of the preceding claims, characterised in that each element is covered with an elastic sheath.

7. A device as claimed in claim 6, characterised in that said sheath is profiled.

8. A device as claimed in claim 7, characterised in that the profile is formed by radial successive grooves and ridges.

9. A device as claimed in any one of claims 6 to 8, characterised in that the sheath is formed by a plurality of annular bodies separated by axial spacers of smaller diameter than the annular bodies.

10. A device as claimed in claim 9, characterised in that the circumferential edge of each annular body is bevelled on both sides.

11. A device as claimed in any preceding claim, characterised in that the two groups of elements are connected to a single conveyor chain.

12. A device for grading to size bulbs or tubers, substantially as described hereinbefore with reference to the accompanying drawings.