FRUIT SORTING TABLE WITH ADAPTIVE SCREEN

Abstract

A fruit sorting table includes: a conveyor for conveying a fruit crop along a conveying plane, between an intake area and a discharge area, a screen extending in the conveying plane between the intake area and the discharge area, the screen having openings for sorted fruit to pass through from the conveying plane to an area for receiving sorted fruit situated under the conveying plane. The sorting table has at least one device for measuring one of a quantity of fruit and a flow rate of fruit passing through the screen over at least one reference section of the screen, the reference section being situated between the fruit intake area and the discharge area, and set apart from the fruit intake area, a device for adjusting the sorting table in response to the measurement device. Application, in particular, to sorting a grape crop.

Claims

1. Sorting table for fruit including: a conveyor for the conveying of a fruit crop along a conveying plane, between an intake area and a discharge area, a screen, extending in the conveying plane between the intake area and the discharge area, the screen presenting openings for passage of fruit from the conveying plane towards an area for receiving sorted fruit situated under the conveying plane, and an adjustment device of the selectivity of the sorting table, characterized in that: at least one measuring device for either a quantity of fruit or a flow rate of fruit passing through the screen over at least one reference section of the screen, the reference section being situated between the fruit intake area and the discharge area, and at a distance away from the fruit intake area.

2. Sorting table according to claim 1, in which the adjustment device of the selectivity of the sorting table is a device acting on at least one parameter among: a conveying speed of the conveyor; a caliber of the screen; a supply rate of the conveyor; an inclination of the conveyor relative to the horizontal.

3. Sorting table according to claim 1, in which the adjustment device is dependent on the measuring device.

4. Sorting table according to claim 1, in which the measuring device is an integrating measuring device.

5. Sorting table according to claim 1, in which the measuring device includes at least one optical barrier, and a totalizer of openings of the optical barrier.

6. Sorting table according to claim 5, in which the totalizer of openings is a totalizer of a number of openings per time unit.

7. Sorting table according to claim 5, in which the totalizer of openings is configured to establish a relationship between a length of time of opening the optical barrier and a reference duration.

8. Sorting table according to claim 5, in which the totalizer of openings is configured to establish a relationship between a length of time of opening the optical barrier and a length of time of closing the optical barrier.

9. Sorting table according to claim 1, in which the measuring device includes a camera and an image processing system associated with the camera.

10. Sorting table according to claim 1, in which the measuring device includes a deflector positioned in a fruit chute between the reference section of the screen and the area for receiving sorted fruit, and a totalizer of impacts on the deflector.

11. Sorting table according to claim 1, in which the measuring device includes a deflector mounted in pivoting fashion in a fruit chute between a reference section of the screen and the area for receiving sorted fruit, a return spring of the deflector in a resting position, and a sensor of angular deflection of the deflector relative to the resting position.

12. Sorting table according to claim 1, in which the measuring device includes a fruit receptacle and a totalizer of fruit mass in the receptacle.

13. Sorting table according to claim 1, in which the adjusting device acts on the conveying speed and in which the adjusting device includes one among: a drive of a power supply of an electric motor driving the conveyor, a drive for the supply rate of oil passing through a hydraulic motor driving the conveyor, a drive for the supply rate of fuel supplying a thermal engine driving the conveyor, and a gear drive for a transmission driving the conveyor.

14. Sorting table according to claim 1, in which the conveyor is a roller conveyor.

15. Sorting table according to claim 14, in which the roller conveyor includes sorter conveyor rollers forming the screen.

16. Sorting table according to claim 15, in which the adjusting device includes a slide for adjusting a distance between the sorter rollers.

17. Sorting table according to claim 3, in which the adjusting device is servo-driven: to reduce the conveying speed and/or increase the caliber of the screen, and/or reduce the inclination of the conveyor, and/or increase the supply rate of the conveyor when either the quantity of fruit or the flow rate of fruit crossing the reference section of the screen is below a low setpoint, and to increase the conveying speed and/or reduce the caliber of the screen, and/or increase the inclination of the conveyor, and/or reduce the supply rate of the conveyor when either the quantity of fruit or the flow rate of fruit crossing the reference section of the screen exceeds a high setpoint.

18. Sorting table according to claim 1, in which the reference section of the screen presents a length along an axis of conveying comprised between one hundredth and one quarter of the total length of the screen.

19. Sorting table according to claim 1, in which the reference section is situated at a distance from a screen entrance comprised between 75% and 90% of a total length of the screen.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0090] FIG. 1 is a longitudinal section of a sorting table according to the invention.

[0091] FIG. 2 is a perspective view of a conveyor and a screen of a sorting table according to the invention.

[0092] FIG. 3 is a plan view of a sorter-conveyor roller and a measuring device of the sorting table of FIG. 1.

[0093] FIG. 4 is a longitudinal section of another sorting table in conformance with the invention with another type of measuring device.

[0094] FIG. 5 is a longitudinal section of another sorting table in conformance with the invention with another type of measuring device.

[0095] FIG. 6 is a longitudinal section of another sorting table in conformance with the invention with yet another type of measuring device.

[0096] The different figures are represented in free scale.

DETAILED DESCRIPTION OF MODES ON IMPLEMENTATION OF THE INVENTION

[0097] In the following description identical, similar or equivalent portions of the various figures are marked with the same reference identifiers, so as to facilitate the transfer from one figure to another.

[0098] FIG. 1 shows a sorting table 10 in conformance with the invention.

[0099] It comprises a roller conveyor 12 extending from an intake area 14 to a discharge area 16 along a conveying plane 18. The conveying plane is in an essentially horizontal position. However, the sorting table and thus its conveying plane can be inclined relative to the horizontal with a jack mechanism 20.

[0100] A hopper 22 with a variable output is placed above the intake area 14 for dumping a crop into it. In the case of FIG. 1, this is a grape harvest including both grape berries 24 and debris 26 such as leaves, leaf stems or stalks to be eliminated.

[0101] The roller conveyor 12 includes a first series of roller conveyors 28, placed essentially side by side in the conveying plane 18 and perpendicularly to a conveying axis indicated by an arrow C. The arrow C also indicates a conveying direction of the intake area 14 towards the discharge area 16. After the first series of conveyor rollers 28 there is a second series of rollers which are sorter conveyor rollers 30. Sorter conveyor rollers are understood to be rollers between which appropriate spaces are made to let selectively pass fruit or debris of similar or smaller size than the fruit. The sorter conveyor rollers 30 are also positioned in the conveying plane 18, perpendicularly to the conveying axis C, following the conveyor rollers 28.

[0102] On account of the spaces provided between the successive sorter conveyor rollers these constitute a screen 32.

[0103] In the example of FIG. 1, the screen 32 extends in the prolongation of the conveying rollers 28 up to the discharge area 16 of the sorting table 10. The screen presents a caliber depending essentially on the spaces, or passage openings made between the sorter conveyor rollers 30. The caliber of the screen can be adjusted, especially by a sliding device 34 allowing modification of the distance between the sorter conveyor rollers. The sliding device 34 is symbolically represented on FIG. 1.

[0104] The conveyor rollers 28, just like the sorter conveyor rollers 30 are driven in rotation by an electric motor 36 represented symbolically. All the rollers are put into rotation in the same direction, as it happens clockwise in this case of FIG. 1 to move the grape harvest from the intake area 14 towards the discharge area 16, parallel to the conveying axis C.

[0105] As the conveying progresses, when the grape harvest passes over the screen 32, the grape berries 24 in contact with the screen or near the screen pass through the screen to reach an area 40 for receiving sorted fruit under the screen 32 and under the conveying plane 18. A collector of sorted fruit, not shown, may be placed in this area. In this manner, the number of grape berries 24 remaining on the sorting table diminishes as the conveying along the conveying axis C continues.

[0106] The sorting table of FIG. 1 is represented in an optimal configuration in which no more fruit, or almost no more fruit remains on the sorting table at the end of the screen 32 and as the discharge area 16 approaches. So only the debris 26 remains on the sorting table and is dropped in the discharge area to be discarded.

[0107] The screen 32 of the sorting table of FIG. 1 includes a reference section 42 here constituted by two reference sorter conveyor rollers. The reference section 42 is positioned in the vicinity of the end of the screen directed towards the discharge area 16. It is associated to a measuring device 50 intended for measuring a quantity or flow of fruits, here grape berries 24, passing through the screen on the reference section. In the particular example of FIG. 1, the measuring device 50 determines the quantity or flow of fruit crossing the screen between the two sorter conveyor rollers of the reference section 42.

[0108] The measuring device 50 delivers a measurement signal destined for an adjustment device 52 acting on various parameters of the sorting table. This is for example an optical sensor measuring the occultations by the grape berries, or possibly the debris items crossing the sorting table at the reference section 42. The adjustment device 52 acts in particular on the power supply to the electric motor 36 to vary the rotational speed of the rollers 28, 30 and thus the conveying speed. It also acts on the jack mechanism 20 which serves to incline the sorting table. Lastly it acts on the sliding device 34 intended for adjusting the opening and thereby the caliber of the screen 32 of the sorting table. In the case where the sorting table is mounted on a harvesting machine, the adjustment device can also act on the speed of the harvesting machine to adjust the rate of harvested grapes arriving in the intake area of the sorting table. In general, the adjustment device can send a signal to the grape harvest supply system of the sorting table to vary the rate of harvested grapes arriving in the intake area of the sorting table.

[0109] FIG. 2 is a perspective view of a conveyor 12 of a sorting table in conformance with the invention.

[0110] Just like the conveyor of FIG. 1, the conveyor 12 of FIG. 2 extends from an intake area 14 to a discharge area 16. The conveyor is formed by a plurality of rollers 28, 30.

[0111] In the intake area there are four conveyor rollers 28. These rollers are almost contiguous. They serve to spread the crop and trigger its transport along the conveying axis C, perpendicular to the rollers when they are put into rotation. They also serve to remove from between the rollers the juices and very small items of debris such as grape seeds.

[0112] The conveyor rollers 28 are followed by a plurality of sorter conveyor rollers 30 also capable of being put into rotation, in concert with the conveyor rollers 28 for conveying the crop. Each conveyor roller presents a regular alternation of sorting sections 60 and of annular collars 62. The annular collars present a diameter larger than the sorting sections and slightly overlap from one sorter conveyor roller to the next.

[0113] The sorting sections 60, successive conveyor rollers which are opposite, do not touch each other. They present between themselves spaces or openings 66. The spaces 66 are thus delimited by the sorting sections perpendicularly to the conveying axis C and are delimited by the annular collars parallel to the conveying axis C. Thanks to the spaces 66 the sorter conveyor rollers 30 constitute a screen 32.

[0114] A portion of the screen, in the vicinity of the discharge area 16 constitutes the reference section 42 of the screen.

[0115] FIG. 3 is a plan view, parallel to its axis and in a plane perpendicular to the conveying axis C of FIGS. 1 and 2, of a sorter conveyor roller 30 taken in the reference section of the screen.

[0116] One can observe in one of the ends of the sorter conveyor roller a transmission mechanism 64 linked to the electric motor 36, represented symbolically. The transmission mechanism 64 serves to communicate to the sorter conveyor roller 30 a rotational movement for the conveying of the grape harvest.

[0117] The conveyed grape harvest includes grape berries 24 and debris 26 present on the roller, in contact with the sorting sections 60 and the annular collars 62.

[0118] FIG. 3 also shows the measuring device 50 which here includes an optical barrier 70 formed by an emitter 72 and a receiver 74 of a light beam. The receiver 74 forms a totalizer of the opening. The light beam of the optical barrier extends parallel to the sorter conveyor roller 30 under the spaces 66 which separate the sorter sections 60 from those of the following sorter conveyor roller not shown.

[0119] The grape berries which pass through the reference section 42 of the screen 32 thus trigger openings of the optical barrier 70 as they drop towards the area 40 for receiving sorted fruit.

[0120] The measuring device 50, and in particular the totalizer of openings, delivers a signal counting the number of openings or the relative duration of the openings of the optical barrier 70. This signal is directed towards the adjustment device 52 already mentioned in connection with FIG. 1.

[0121] As a complement, or even as a replacement, of the optical barrier, the measuring device may feature a camera 76 associated to an image processing system 78, for example a software control system, to deliver a representative signal of a flow of fruit across the reference section 42 of the screen 32.

[0122] FIG. 4 is a longitudinal section comparable to FIG. 1 and shows another possibility of implementation of the measuring device 50.

[0123] The screen 32 of FIG. 4 presents a reference section 42 formed by three sorter conveyor rollers 30.

[0124] A measuring device 50 is associated to the reference section 42. The measuring device includes a deflector 80, for example a metallic plate mounted under the reference section 42 of the screen 32 so as to be struck by the grape berries 24 which cross the reference section 42 of the screen 32, as they drop towards the area 40 for receiving sorted fruit. The deflector 80 is associated to impact totalizers 82. The impact totalizers may be optical or mechanical devices, for example accelerometers, supplying a measurement signal for the adjustment device 52. The impact totalizers can be calibrated to be sensitive to the dropping of sorted grape berries and not just to simple seeds, for example.

[0125] FIG. 5 shows a variant of the device of FIG. 4 in which the reference section extends over four consecutive sorter conveyor rollers. The measuring device 50 also includes a deflector 80. Each deflector 80 is mounted in pivoting fashion in the fruit chute under the reference section 42 of the screen 32.

[0126] The deflector 80 is charged by a return spring 86 which returns it to a resting position. The falling grape berries 24 passing through the reference section 42 of the screen 32 and reaching the deflector 80 tend to make the deflector pivot out of its resting position. The pivoting angle varies with the flow of the grape berries crossing the reference sections. A sensor of angular deflection 88, for example a sensor with a potentiometer or an angular optical sensor measures the angle of deflection of the deflector and delivers a representative signal of the flow of berries that is intended for the adjustment device 52. In fact, in this mode of implementation the angular deflection of the deflector 80, relative to its resting position is proportional to the flow of berries, or at least representative of a flow of berries reaching the deflector, and hence of the flow of berries crossing the reference section 42 of the screen.

[0127] FIG. 6 is a longitudinal section of a sorting table comparable to that of FIG. 1 and illustrates yet another possibility of implementation of the measuring device 50 of the flow of berries through a reference section 42 of the screen 32.

[0128] The measuring device of the flow of berries of FIG. 6 includes a receptacle 90 positioned in the area 40 for receiving sorted fruit. The receptacle 90 presents an opening 92 adjusted to the dimension of the reference section 42 of the screen 32 and positioned below the reference section. In this way, the berries 24 passing through the screen 32 through the reference section 42 are collected in the receptacle 90.

[0129] The receptacle 90 is associated to one or several strain sensors 94, and thus constitutes scales or a mass totalizer making it possible to measure a mass of collected berries.

[0130] The strain sensor can deliver a signal of mass, mass growth or mass growth per time unit, representative of the flow of berries across the reference section 42 of the screen. This signal is provided to the adjustment device 52 so as to control the parameters of the sorting table.

[0131] In effect, as shown previously, it is possible to adjust the conveying speed, the intake rate, the incline of the sorting table and the caliber in order to obtain a target flow of berries across the reference section. This target flow is such that the number of berries arriving at the discharge area 16 is virtually zero.