GB2124571A

GB2124571A - Fruit-grading apparatus

Info

Publication number: GB2124571A
Application number: GB08221976A
Authority: GB
Inventors: Reginald Arthur Weeks
Original assignee: National Research Development Corp UK
Current assignee: National Research Development Corp UK
Priority date: 1982-07-29
Filing date: 1982-07-29
Publication date: 1984-02-22
Also published as: GB2124571B

Abstract

A fruit-grading apparatus comprises a water flotation tank 12 provided with a constant recirculation of water which carries the fruit 20 as a floating mass towards a cup-type conveyor 14. On its passage through the tank the fruit is selected according to size at belt 32, displayed for manual rejection at belt 40, and cleaned by brushes 42. The remaining fruit picked up by conveyor 14 is presented to weighing apparatus at 54. <IMAGE>

Description

SPECIFICATION Fruit-grading apparatus The present invention relates to a fruit-grading apparatus. Apple-grading apparatus is already known in which apples are elevated from a water flotation tank by a roller elevator which deposits the apples on to a conveyor. This latter carries the fruit past cleaning brushes and a fresh water rinse to a drying location where fans force a blast of cold air onto the cleaned apples. The clean dry apples are next fed to a sorting table where apples which are damaged or otherwise of unacceptable quality are removed manually and the remaining apples are automatically loaded onto a roller elevator singulator. The singulator discharges the apples row by row into appropriate conveyor cups which carry them away for packing and eventual transport from the site.

This known fruit grading apparatus is subject to two principal disadvantages. Firstly, the frequent transfer of the fruit from one part of the apparatus to another increases the risk of damaging the fruit.

Secondly, the throughput of fruit through the apparatus is set by the efficiency of the roller elevator in removing fruit in a steady uninterrupted stream from the flotation tank at the input end of the apparatus and it is not uncommon for the apparatus to be working at only sixty to seventy percent maximum capacity because the roller elevator is not fully loaded.

It is an object of the invention to provide a fruitgrading apparatus in which these disadvantages are avoided or at least substantially reduced.

According to the present invention, a fruitgrading apparatus comprises a water flotation tank and a cup-type conveyor which enters the tank to collect the fruit individually in the conveyor cups where the unacceptable fruit is retained until leaving the apparatus for transport from the site.

Conveniently, the transfer of fruit from one part of the apparatus to another is carried out when the fruit is supported by the water in the tank. This minimises the chances of the fruit being damaged during its passage through the apparatus.

Throughput is also improved because the presentation of the fruit en masse to the conveyor cups at the flotation tanks results in virtually all the cups being filled.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figures 1 a and lb are the left and right hand parts respectively of a schematic vertical section of an apparatus in accordance with the present invention; Figure 2 is a simplified schematic plan view of that part of the apparatus also appearing in Figure 1 a; and Figure 3 shows on an enlarged scale a simplified underneath perspective view of part of the apparatus illustrated in the Figures 1 a, 16 and 2.

Thus referring now to the drawings, an apple grading apparatus 10 according to the present invention comprises a water flotation tank 12 and a cup-type conveyor 14 which enters the tank to collect the fruit individually and thereafter transport it through the rest of the apparatus towards the discharge conveyors 1 6, 1 7.

Reference numeral 1 8 indicates guides for guiding the fruit from the tank 1 2 onto the conveyor 1 4.

In more detail, the fruit 20 is first introduced into the apparatus in an open-topped container 22 lying below the water level 24 in the tank.

As viewed in Figures 1 a and 2, the water-flow through the tank 12 is from left to right. This flow is induced by a suction pump 26. Water leaving the tank is returned by the pump through pipe 28 to a sub-chamber 30 at the inlet end of the apparatus from whence it spills over a sluice member 31 back into the tank 12.

This constant recirculation of water through.

the tank 12 carries the apples 20 as a floating mass of fruit towards a perforated belt 32 which removes and then returns apples above a preselected size to the water flow in tank 12.

Apples below this size fall through the perforations in belt 32 upstream of a deflector 34 which diverts them on to a small-fruit elevator 36. This latter discharges the rejected fruit onto a cross-conveyor 38 for removal to an appropriate site.

After its return to the water flow in tank 12, the remaining fruit passes onto a display belt 40 (not shown in Figure 2) which once again removes and then returns the fruit to the water flow. During its passage above the water surface, rejects and Class 3 fruit will be removed manually by an operative and to facilitate visual inspection, belt 40 is preferably of the rotating roller type.

After returning to the water flow, the fruit which has passed inspection moves below rotating cleaning brushes 42 on to the cup-type conveyor 14, assisted by guides 1 8 as above described. As already explained, the fact that the fruit will be presented en masse to conveyor 1 4 will ensure that the conveyor is virtually fully loaded. It will also be appreciated that loading and unloading of belts 32, 40 and 14 is in all cases carried out when the fruit is supported by the water in the tank 12 and as a result the amount of fruit damaged during its passage through the apparatus will be minimal.

Referring now to Figure 1 b, fruit leaving the water tank on conveyor 14 passes under highvelocity cold-air fans 44 which blow excess water from the fruit back into the tank 12.

The fruit next passes through a drying section 46 where hot air is blown on to the fruit by fans 48. Reference numeral 50 indicates a moistureextraction duct.

The conveyor 14 now carries the dried apples through display section 52 and weighing section 54 where quality selection is carried out manually and weight selection automatically.

In one embodiment, for example, the conveyor 14 comprises four lanes of fruit-containing cups, one of which is shown in Figure 3.

Each cup is formed with spaces 56, 57 to allow contradirectional moving belts positioned beneath the cup lanes to engage and rotate the fruit to facilitate visual inspection at section 52. Visual information determined in this way is then entered manually into a memory system e.g. by depressing push buttons carried by the cups, or by touching selected fruit with a movable sensor to record the selection electronically.

Each cup is pivotally linked to the cross member of a chain-drive arrangement for the cups so that, at the weighing section 54, the weight of each cup and its contents is supported by a weighing pad engaged by the central web portion 59 of the cups. This information too can be entered either mechanically or electronically into the memory system which operates when the belt 14 reaches the cross-conveyors 1 6, 1 7 to unload the fruit onto the appropriate cross-conveyor, e.g.

conveyor 1 6 for Class 1 fruit and conveyor 1 7 for Class 2 fruit.

Details of the cups and different ways in which they can be mounted for quality and weight selection using a travelling memory push-button memory system may be obtained from UK Patent 1548301 (NRDC), UK Patent 1549785 (NRDC) and UK Patent Application 8134298 (NRDC).

Semi-automatic systems in which visual information is recorded electronically are disclosed in UK Patent 1 534590 (NRDC) and in UK Patent Application 8211777 (NRDC). These latter systems will preferably be modified by replacing the ejection plungers described in these last two documents by the cup-release discharge arrangement described in the three previously mentioned documents.

Fruit discharged on to cross-conveyor 1 6 or cross-conveyor 1 7 in accordance with its weight and quality characteristics as above described is then removed by these conveyors to a packing site where it is packed for transport.

Although intended primarily for use with apples, it will be appreciated that the illustrated apparatus can be used for other fruit, e.g. pears, if desired, and any minor modifications, e.g. change in cup size, can readily be accommodated.

Claims

1. A fruit-grading apparatus comprising a water flotation tank and a cup-type conveyor which enters the tank to collect the fruit individually in the conveyor cups where the acceptable fruit is retained until leaving the apparatus for transport from the site.

2. A fruit-grading apparatus as claimed in Claim 1 in which the transfer of fruit from one part of the apparatus to another is carried out when the fruit is supported by the water in the tank.

3. A fruit-grading apparatus as claimed in Claim 1 and substantially as hereinbefore described with reference to and/or as illustrated in the accompanying drawings.