METHOD OF AND APPARATUS FOR SORTING TOBACCO LEAVES

• US 3,770,112 A
• Filed: 09/16/1971
• Issued: 11/06/1973
• Est. Priority Date: 06/16/1971
• Status: Expired due to Term

• Current Assignee: Emil S. Asfour
• Original Assignee: Emil S. Asfour
• Inventors: Asfour, Emil S.
• Primary Examiner(s): Schacher, Richard A.
• Application Number:
  US05/181,160
• Time in Patent Office: 782 Days
• Field of Search: 209/75,73,111.6 131/138,131,110,84B,146,149,21B,21R
• US Class Current: 209/557
• CPC Class Codes: A24B 3/16 Classifying or aligning leaves
• CPC Class Codes: B07C 5/342 according to optical properties, e.g. colour according to radiation transmittivity B07C5/3416
• CPC Class Codes: B07C 5/362 Separating or distributor mechanisms switches for postal sorting B07C3/065; particular discharging devices for B65G47/74
• CPC Class Codes: Y10S 209/905 Feeder conveyor holding item by suction
• CPC Class Codes: Y10S 209/931 Materials of construction

Abstract

Apparatus for sorting leaves, particularly tobacco leaves, has a vibrating type conveyor provided with successive surfaces of different inclination to separate the leaves in the longitudinal direction of their motion. After separation the leaves are passed through a sorting station which separates foreign bodies. The leaves are then passed to a sorting station where they are classified, by an optical device according to color differences.

Claims

1. A sorting apparatus for sorting leaves and similar material, more particularly tobacco leaves, characterized by a separating device having parallel channels each provided with a spreading device for the leaf material in the longitudinal direction, by a subsequent first sorting station with a conveyor belt designed to hold individual leaves and a separating unit for foreign bodies, and by a second sorting station along said conveyor belt with a testing member for the quality of the individual leaves and a signalling member controlled by the testing member which actuates classification device for the leaves, said spreading device comprising a vibrating conveyor having several conveyor surfaces rising in the direction of movement, the steepness of the said conveyor surfaces decreasing in successive conveyor sections, and a last conveying section with a substantially horizontal conVeyor surface, and including a common vibrator for all said conveyor surfaces.

2. A sorting apparatus for sorting leaves and similar material, more particularly tobacco leaves, characterized by a separating device having parallel channels each provided with a spreading device for the leaf material in the longitudinal direction, by a subsequent first sorting station with a conveyor belt designed to hold individual leaves and a separating unit for foreign bodies, and by a second sorting station along said conveyor belt with a testing member for the quality of the individual leaves and a signalling member controlled by the testing member which actuates classification device for the leaves, said conveyor belt per channel being made of a material impermeable to air and provided with perforations grouped into clusters which are arranged in spaced relationship along the conveyor belt, the spaces being somewhat larger than the leaves to be held, the said conveyor belt passing around a rotating drum at the entrance of the channel involved, the said drum having a shell which is permeable to air and of which the half facing the entrance accommodates a hollow body with a perforated shell and a connecting line for an underpressure system.

3. A sorting apparatus according to claim 2 characterized by a subdivision of the hollow body into a plurality of sectors of which each can be connected to an underpressure system independently of the others.

4. A sorting apparatus according to claim 2 characterized by a radially arranged adjustable partition arranged in the hollow body, the said partition subdividing the same into an upper and a lower hollow space of which only the upper one can be connected to an underpressure system.

5. A sorting apparatus according to claim 2 characterized by a classification device which can be actuated by the signalling device and which comprises a rotating drum around which the conveyor belt passes in a loop of approximately 180* of angle, the said drum having a shell permeable to air, by two sector-type hollow bodies arranged inside the drum and provided with perforated shell surfaces facing the conveyor belt, of which hollow bodies each can be connected, via a line and an electrically operable valve, to a further flat hollow body which has a perforated wall facing the conveyor belt running off the drum and can be connectd to the underpressure system via the electrically operable valve, by control circuits between the valves and the signalling device, and by sorting channels arranged underneath this classification device, the said sorting channels extending transversely over all classification devices of the individual parallel channels.

6. A sorting apparatus according to claim 5 characterized by the fact that the signalling device and the control circuits to the valves are so designed that the appearance of a signal corresponding to the quality class of the first sorting channel causes the valve for the upper sector-type hollow body to open, that the appearance of a signal corresponding to the quality class of the second sorting channel causes the valves of the two sector-type hollow bodies to open, and that the appearance of a signal corresponding to the quality class of the third sorting channel causes the valves of the two sector-type hollow bodies and the flat hollow body to open, which results in that the leaves located on each group of holes in the conveyor belt are held by suction only while the group of holes involved passes through the range of the perforated walls of those hollow bodies of which the valves are open and then drop into the sorting channels which are located underneath.

7. A sorting apparatus for sorting leaves and similar material, more particularly tobacco leaves, characterized by a separating device having parallel channels each provided with a spreading device for the leaf material in the longitudinal direction, by a subsequent first sorting station with a conveyor belt designed to hold individual leaves and a separating unit for foreign bodies, and by a second sorting station along said conveyor belt with a testing member for the quality of the individual leaves and a signalling member controlled by the testing member which actuates classification device for the leaves, said separating unit for foreign bodies comprising a gap downstream of the last conveyor surface of the spreading device which is passed by the conveyor belt in the upward direction, and a catching device arranged underneath the gap to accommodate the foreign bodies dropping through the gap.

8. A sorting apparatus according to claim 7 characterized by a hollow body arranged underneath the gap, the said hollow body having an adjustable connection to a compressed-air system so designed that an air current of adjustable force can be obtained in the upward direction through the gap.

9. A sorting apparatus according to claim 7 characterized by a plate located underneath the gap which causes the conveyor belt to be shielded and of which the distance from the gap is adjustable.

10. A sorting apparatus for sorting leaves and similar material, more particularly tobacco leaves, characterized by a separating device having parallel channels each provided with a spreading device for the leaf material in the longitudinal direction, by a subsequent first sorting station with a conveyor belt designed to hold individual leaves and a separating unit for foreign bodies, and by a second sorting station along said conveyor belt with a testing member for the quality of the individual leaves and a signalling member controlled by the testing member which actuates classification device for the leaves, said conveyor belt per channel being made of a material impermeable to air and provided with perforations grouped into clusters arranged in spaced relationship along the conveyor belt, the space being somewhat larger than the leaves to be held, the said conveyor belt passing over drums with shells permeable to air and over guide rolls and has its group of holes in the area where individual leaves are caught and held pass over perforated wall portions of flat or sector-type hollow bodies of which those located in the area between the entrance and the classification device are permanently connected to an underpressure system while the hollow bodies associated with the classification device are connected to the underpressure system via electrically operable valves, and including a second conveyor belt which is provided with groups of holes like the first conveyor belt and passes over drums with shells permeable to air and, in so doing, passes for a length of its path in parallel with and close to the first conveyor belt which is moved in the downward direction, in the range of the classification device has its groups of holes passing over perforated wall portions of flat or sector-type hollow bodies which are connected, via electrically operable valves, to an underpressure system, and by sorting channels arranged underneath the classification device, the said channels extending transversely over all classification devices of the individual parallel channels, and by control circuits arranged between the valves and the signalling device.

11. A sorting device according to claim 10 characterized by the fact that the signalling device and the control circuits to the valves are so designed that the appearance of the signal corresponding to the quality class of the first sorting channel causes the underpressure valves to open for the flat hollow body located behind the downward running section of the first conveyor belt and the sector-type hollow body located downstream of the first body as well as for the flat hollow body located behind the return section of the first conveyor belt, that the appearance of a signal corresponding to the quality class of the second sorting channel causes the underpressure valves to open as in the presence of the signal corresponding to the quality class of the first sorting channel with the excEption of that for the hollow body located behind the returning lower section of the conveyor belt, that the appearance of a signal corresponding to the quality class of the third sorting channel causes the underpressure valves to open for the hollow bodies located behind the second conveyor belt in the range of the section parallel with the first conveyor belt as well as for the flat hollow body which is arranged behind the section of the second conveyor belt moving away from the parallel range, and that the appearance of a signal corresponding to the quality class of the fourth sorting channel causes the underpressure valves to open as in the presence of the signal corresponding to the quality class of the third sorting channel and additionally the underpressure valve of a further sector-type hollow body arranged directly downstream of the flat hollow body which has for a result that the leaves located on the various groups of holes in the first conveyor belt are held fast by suction as long as the group of holes involved passes through the range of those hollow bodies of which the underpressure valves are open thus dropping into the first and, respectively, second sorting channel located underneath, or are taken over by the suction of a group of holes in the second conveyor belt and held fast while the group of holes involved passes through the range of the perforated walls of those hollow bodies of which the underpressure valves are open so that they drop into the third and, respectively fourth sorting channel located underneath.