GB2170388A

GB2170388A - Material-separating assemblies

Info

Publication number: GB2170388A
Application number: GB08601086A
Authority: GB
Inventors: William Peter Billington
Original assignee: National Research Development Corp UK
Current assignee: National Research Development Corp UK
Priority date: 1985-01-18
Filing date: 1986-01-17
Publication date: 1986-08-06
Also published as: GB8601086D0; GB8501300D0; DE3601280A1; NL8600094A; GB2170388B

Abstract

A root-crop harvester 10 has a soil-separating web 12 passing in an S-shaped configuration about the two rollers 18, 19 of a vibration unit 21 for the web. In operation, the unit 21 oscillates about a horizontal pivot axis 27 parallel to the conveying surface of the web thereby alternately to reinforce and oppose the driving action of the web-driving rotor 18. This produces the desired in-plane vibrations in the web 12. The soil-separating assembly may be adapted for separation of other materials e.g. blackcurrents from leaves harvested with the fruit. <IMAGE>

Description

SPECIFICATION Material-separating assemblies The present invention relates to materialseparating assemblies and in particular, but not exclusively, to soil-separating assemblies e.g. for use in or with root-crop harvesters, in particular, but not exclusively, carrot harvesters.

According to the present invention, a materialseparating assembly, e.g. for use with root-crop lifting means, comprises a conveyor sieve, a drive rotor and an idling rotor about which rotors the conveyor sieve passes in an S-shaped configuration, a horizontally pivoted support means for the two rotors, and drive means for oscillating the support means about its horizontal pivot axis so as to provide in-plane vibrations to the conveyor sieve.

Conveniently, the assembly includes a root-crop lifting means comprising one or more oscillating or rigid shares. Conveniently, the crop feed from the lifting means to the conveyor sieve is performed or assisted by a transfer device such as a roller e.g. a plain roller, or a pivoted plate assembly, for example.

Conveniently, the transfer device includes a vertically agitated'transfer conveyor positioned between the conveyor sieve and the roller or pivoted plate, as the case may be.

Conveniently, the drive means is controlled by a control means operative to control the severity of the in-plane vibrations imparted to the conveyor sieve.

The invention also includes a root-crop harvester incorporating a material-separating assembly according to the present invention. In this case, speed control means are preferably provided for varying the speed of the conveyor sieve independently of the ground speed of the harvester.

The invention further includes a static materialseparation plant including a material-separating assembly according to the present invention.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawing in which: Figure 1 illustrates, in diagrammatic form, a side elevation of a carrot harvester according to the invention; and Figure 2 shows, on a larger scale, part of a modification of this embodiment.

Thus referring first to Figure 1 of the drawing, a carrot harvester 10 in accordance with the present invention, comprises a conveyor sieve or "web" 12 passing around front nose cones 14, a rear support roller 16 and the two sprocket rotors 18, 19 of a vibration unit 21 for vibrating the conveyor sieve 12.

This latter is preferably of the so-called "continental web" type i.e. one composed of round-section steel rods flattened at each end and attached there to a continuous belt of composite material.

Unit 21 is completed by a pivotal support member 25 which is oscillated by a crankshaft 27 about a horizontal pivot axis 29 lying substantially parallel to the surface of the conveyor sieve.

Of the two rotors supported on member 25, the second (19) is idling while the first (18) is driven, e.g.

through a flexible shaft (not shown), to provide the principle drive to the conveyor sieve 12. If desired, the roles of rollers 18 and 19 may be interchanged.

At the front end of the harvester, crop is fed from the shares to the transfer means which is preferably, though not necessarily, an integral part of each share assembly. Conveniently, oscillating shares are used to help break up the soil and together with a transfer device assist the movement of the crop from the digging shares and onto the conveyor sieve.

In the illustrated embodiment, the root-crop (and soil) picked up by conventional horizontallyoscillating share 30 is fed on to the conveyor sieve 12 via a plain roller 32. In the modification of Figure 2, the roller 32 is replaced by a series of laterally pivoted plates 34 attached to the oscillating share assembly.

In further modifications, a conventional verticallyagitated transfer conveyor e.g. of the same form as web 12, is included between the web 12 and the roller 32 or plates 34, as the case may be, so as to increase the distance available to the incoming stream of soil and crop to spread across the full width dimension of the web 12.

In yet further modifications, these various transfer devices are omitted and the shares 30 are arranged to feed the harvested material direct on to web 12.

In operation of the harvester, a steady drive is applied to the roller 28 so that when the oscillating support member 25 is moving in the general cropconveying direction of the web 12, the speed of the web will be increased. When the member 25 is moving in the opposite direction to the web, however, the speed will be decreased. Thus the web 12 will be vibrated substantially within its own plane as the oscillatory motion of support 25 alternately reinforces and then opposes the overall motion of the web. This vibratory motion of the section efficiently separates the soil from the root-crop with minimal risk of damaging this latter.

The amplitude of the vibratory motion can be altered to suit the prevailing conditions within the range 10 mm to 30 mm, for example, by altering the crank throw. Likewise, the frequency of oscillation can be similarly varied between, say, 100 cycles per minute and 400 cycles per minute, by altering the speed of the crank drives to links 43. Typical acceleration/deceleration values for a 20 mm amplitude stroke of the cranks might be 0.22 to 3.6 g, for example.

Although the illustrated conveyor sieve assembly has been described as incorporated in a carrot harvester, it will be appreciated that it is equally suited for incorporation, with minor modifications if necessary, into otherforms of root-crop harvester, e.g. harvesters for potatoes, sugar beet and possibly also daffodil bulbs etc. and also potato diggers.

Although intended primarily for use in separating soil and root crop, it is envisaged that the separating assemblies above described could also be used to separate other materials of dissimilar size and/or shape. This might, of course, require some minor adaptation of the illustrated embodiment e.g. a different spacing of the rods in the conveyor web or even a different design of web altogether, the web apertures in both cases preferably being selected to match one of the products to be separated.

One example of an alternative use ofthe kind referred to above, would be the separating out of blackcurrants from leaves harvested with the fruit.

In this case, this conveyor 12, which may be a proprietary item, will preferably present a series of apertures spaced across the width of the conveyor so that in operation of the assembly, the leaves will be carried away by the conveyor 12 while the blackcurrants will fall through the apertures in the conveyor and into an appropriate receptabie (not shown).

The invention also extends to a static materialseparation plant having a material-separating assembly of any of the kinds above described in accordance with the present invention.

Claims

1. A material-separating assembly comprising a conveyor sieve, a drive rotor and an idling rotor about which rotors the conveyor sieve passes in an S-shaped configuration, a horizontally pivoted support means for the two rotors, and drive means for oscillating the support means about its horizontal pivot axis so as to provide in-plane vibrations to the conveyor sieve.

2. An assembly as claimed in Claim 1 in which the assembly includes a root-crop lifting means comprising one or more oscillating or rigid shares.

3. An assembly as claimed in Claim 1 or Claim 2 in which the crop feed to the conveyor sieve is performed or assisted by a transfer device.

4. An assembly as claimed in Claim 3 in which the transfer device comprises a roller.

5. An assembly as claimed in Claim 3 in which the transfer device comprises a pivoted plate assembly.

6. An assembly as claimed in Claim 4 or Claim 5 in which the transfer device additionally includes a vertically-agitated transfer conveyor positioned between the conveyor sieve and the roller or pivoted plate assembly, as the case may be.

7. An assembly as claimed in any preceding claim in which the drive means is controlled by a control means operative to control the severity of the inplane vibrations imparted to the conveyor sieve.

8. A root-crop harvester incorporating a materialseparating assembly according to any preceding ciaim.

9. A root-crop harvester as claimed in Claim 8 in which speed control means are provided for varying the speed of the conveyor sieve independently of the ground speed ofthe harvester

10. A static material-separation plant including a material-separating assembly as claimed in any of Claims 1 to 7.

11. A material-separating assembly, root-crop harvester or static material-separation plant substantially as hereinbefore described with reference to, and/or as illustrated, in Figure 1, or Figures 1 and 2, ofthe accompanying drawing.