Apparatus for sorting material

Abstract: Apparatus for sorting material (13,14) into desired and undesired portions thereof comprising support means (10,11) for supporting material (13,14) to be sorted; examination means (20,32) for determining the presence on the support means (10) of any undesired material (13); at least one conduit means (22,23) having an inlet pipe (22) through which undesired material (13) may be withdrawn from the support means (10,11); suction means (25) for communicating with the or each conduit means (22,23) so as to cause undesired material (13) to be withdrawn therethrough by suction; and movement effecting means (26), controlled by the examination means, for moving the inlet pipe (22) of the or each conduit means (22,23) between a first position in which it is spaced from the support means (10,11) and is closed to the suction means 925), and a second position in which it is adjacent to the support means (10,11) and is open to the suction means (25). The end portion (44) of the inlet pipe (22) adjacent the support means (10,11) is reduced in internal cross section in a direction away from the support means.

Description: This invention concerns apparatus for sorting material such, for example, as a foodstuff, into desired and undesired portions thereof. The term "material", as used herein, is intended to have a broad meaning so as to include pieces of solid material; particulate material; material, eg. a slurry, containing a liquid; and material in the form of a purée or the like. Moreover the material may be of animal, mineral or vegetable origin or any combination thereof. Although not so restricted, however, the invention is particularly applicable to the sorting of foodstuffs to remove blemished or unwanted parts thereof. It is known in a canning process for canning tomato pieces to pass these pieces on a conveyor belt past a number of operatives who try to remove any calyx or blemished material therefrom by hand. This, however, is a slow and expensive procedure which is not particularly effective in removing all the undesired material and results in substantial loss of good product. In US-A-4,186,836 there is disclosed apparatus for sorting material into desired and undesired portions thereof comprising support means for supporting material to be sorted; examination means for determining the presence on the support means of any undesired material; conduit means having a row of inlet pipes arranged transversely of the support means, through which undesired material may be withdrawn from the support means; suction means for communicating with the inlet pipe so as to cause undesired material to be withdrawn therethrough by suction; and movement effecting means, controlled by the examination means, for moving each selected inlet pipe between a first position in which it is spaced from the support means and is closed to the suction means, and a second position in which it is adjacent to the support means and is open to the suction means. The inlet pipes are contiguous square cross section tubes whose bottom is open and the edges of three sides are cut back to leave a lip on the lower edge of the fourth side. According to the present invention, there is provided an apparatus for sorting material into desired and undesired portions, comprising support means for supporting material to be sorted; examination means for determining the presence on the support means of any undesired material; at least one conduit means having an inlet pipe through which undesired material may be withdrawn from the support means; suction means for communicating with the inlet pipe so as to cause undesired material to be withdrawn therethrough by suction; and movement effecting means, controlled by the examination means, for moving the inlet pipe of the or each conduit means between a first position in which it is spaced from the support means and is close to the suction means, and a second position in which it is adjacent to the support means and is open to the suction means, characterised in that the internal cross section of the inlet pipe is reduced in a direction away from the support means. Preferably, the reduction in cross section is in the end portion of the inlet pipe adjacent the support means. Advantageously, the end portion of the inlet pipe has a planar edge adjacent the support means. The invention is illustrated, merely by way of example, in the accompanying drawings, in which: Figure 1 is a diagrammatic sectional elevation of apparatus for sorting material into desired and undesired portions, to which the invention is applicable; Figure 2 is a broken away plan view of part of the apparatus of Figure 1; Figure 3 is a diagrammatic perspective view of a suction portion of an embodiment of an apparatus according to the present invention; and Figure 4 is a cross-sectional view of a part of the structure shown in Figure 3. Referring first to Figures 1 and 2, an endless conveyor belt 10, which is driven by means not shown, has an upper run 11 onto an upstream portion of which there are delivered, by a feed conveyor 12, pieces of material (eg. pieces of tomato) comprising blemished or other undesirable pieces, eg. calyces, 13 which it is desired to remove, and unblemished pieces 14. The movement of the conveyor belt 10 takes the pieces 13, 14 past a rotary spreader member 15 by means of which the pieces 13, 14 can be formed into a substantially level layer on the conveyor belt 10. The rotary spreader 15 may, however, be replaced by a reciprocating spreader or by any other spreader. Each of the pieces 13, 14 is moved by the conveyor belt 10 past a viewing station 16 where it is illuminated by lamps 17 and is viewed by a camera 20 having an optical system 21. After being so viewed, each of the pieces 13, 14 is carried by the conveyor belt 10 beneath one of a plurality of inlet pipes 22 each of which forms an inlet portion of a respective conduit means whose remaining portion is constituted by a conduit 23. As will be seen from Figure 2, there are two staggered rows of inlet pipes 22 which are arranged transversely of the conveyor belt 10 so as collectively to extend from one edge of the conveyor belt 10 to the opposite edge thereof, whereby to ensure that any blemished piece 13 will pass directly beneath an inlet pipe 22. Each of the conduits 23 has an outlet portion 24 which is disposed within a common suction vessel 25 which is provided with means (not shown) for subjecting the suction vessel 25 to suction throughout a sorting operation. Thus blemished pieces 13 may be withdrawn from the conveyor belt 10 by suction so as to pass through the conduit means 22, 23. Each inlet pipe 22 is movable by a respective air cylinder 26 or other means between a first position in which it is spaced from the conveyor belt 10 and a second position in which it is adjacent to the latter. In Figure 1, the left hand one of the two inlet pipes 22 illustrated therein is shown as being in the first position while the right hand one of the two inlet pipes 22 is shown as being in the second position. As clearly shown in Figure 1, each inlet pipe 22, when in its first position, is out of communication with its respective conduit 23, whereas when it is in its second position, it is in communication with its respective conduit 23. In other words, the part 27 of each inlet pipe 22 remote from the conveyor belt 10 has a valve action with the adjacent part of its respective conduit 23, the said valve being open only when the inlet pipe 22 is in its second position so that the inlet pipe 22 is subjected to suction only at that time. Each air cylinder 26 is double-acting and is arranged to be driven by compressed air by way of one or other of two compressed air supply pipes 30, the supply of compressed air to each pair of supply pipes 30 being controlled by a respective solenoid valve 31. Each of the solenoid valves 31 is controlled by a electronic control system 32 which forms part of an examination means for determining the presence on the conveyor belt 10 of the blemished pieces 13, the said examination means also comprising the camera 20. The examination means 20, 32 is such that, on detecting a blemished piece 13 at the viewing station 16, a signal is sent by the electronic control system 32 to the respective solenoid valve 31 so that the respective inlet pipe 22 is moved by the respective air cylinder 26 into its said second position after a delay such that the blemished piece 31 reaches the respective inlet pipe 22 at that time. Accordingly, the blemished pieces 13 are removed by suction into the suction vessel 25, whereas the unblemished pieces 14 fall off the downstream end of the conveyor belt 10 into a receptacle 33. The apparatus shown in Figures 1 and 2 is suitable for sorting whole tomatoes as well as tomato puree and may be used for a variety of other purposes such as the removal of black material from a kaolin slurry or the removal of burnt or discoloured material from fruit intended for use in a jam or other foodstuff. In Figures 3 and 4 there is shown a part of an embodiment of an apparatus according to the present invention which is generally similar to that of Figures 1 and 2 and which for this reason will not be described in detail, like reference numerals indicating like parts. In the embodiment of Figures 3 and 4, however, all the conduits 23 are arranged longitudinally of and are arranged to communicate with a common manifold 41 which is connected (by means not shown) to a suction source such as the suction vessel 25 shown in Figures 1 and 3. The internal cross-section of the common manifold 41 increases in the direction of flow therethrough so that each of the conduits 23 is subjected to substantially the same degree of suction, whereby to assist in preventing material which has been removed from the conveyor belt 10 from falling back onto and to the latter or from being precipitated onto and building up on a wall or walls of the common manifold 41. That is to say, if all, or a large number, of the conduits 23 were open at the same time, and if the internal cross-section of the common manifold 41 were constant along its length, the suction source would need to be able to exert a considerable suction force to ensure that the suction was adequate at the conduits 23 most distant from the suction source. The tapering of the common manifold 41, however, reduces the degree of suction which needs to be exerted by the suction source so as to ensure that there will always be an adequate flow of air through the common manifold 41 such as will keep the removed material in suspension therein. The smaller diameter end 43 of the common manifold 41 may communicate with a valve (not shown) which automatically moves in a closing or opening direction when the air pressure at the smaller diameter end 43 falls or rises respectively so as to produce automatic stabilisation of the air pressure in the common manifold 41. As shown in Figure 4, the inlet pipe 22 of each conduit 23 has an internal cross-section at its end portion 44 adjacent the conveyor belt 10 which is reduced in a direction away from the latter. This accelerates the air passing through the end portion 44 and thus helps to ensure that undesired material passes through the end portion 44 and so into the common manifold 41.

Claims: An apparatus for sorting material (13,14) into desired and undesired portions thereof, comprising support means (10,11) for supporting material (13,14) to be sorted; examination means (20,32) for determining the presence on the support means (10,11) of any undesired material (13); at least one conduit means (22,23) having an inlet pipe (22) through which undesired material (13) may be withdrawn from the support means (10,11); suction means (25) for communicating with the inlet pipe (22) so as to cause undesired material (13) to be withdrawn therethrough by suction; and movement effecting means (26), controlled by the examination means (20,32), for moving the inlet pipe (22) of the or each conduit means (22,23) between a first position in which it is spaced from the support means (10,11) and is close to the suction means (25), and a second position in which it is adjacent to the support means (10,11) and is open to the suction means (25), characterised in that the internal cross section of the inlet pipe (22) is reduced in a direction away from the support means (10,11). An apparatus according to claim 1, characterised in that the reduction in cross section is in the end portion (44) of the inlet pipe (22) adjacent the support means (10,11). An apparatus according to claim 1 or 2, characterised in that the end portion (44) of the inlet pipe (22) has a planar edge adjacent the support means (10,11).

Inventors: DEEFHOLTS BENEDICT MARK MURRAY, LOW JOHN MENZIES, MILBANK JOHN ERNEST HARRY, LOW, JOHN MENZIES, MILBANK, JOHN ERNEST HARRY
Applicants: SORTEX LTD, SORTEX LIMITED
Application year: 1991
Main classification: B07C5
IPC codes: B07C5