AU2009201445A1 - A lettuce harvester - Google Patents

Description

S&F Ref: 903103 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address Mulyan Pty Ltd, of Applicant: an Australian company, ACN 000 026 719, of North Logan Road, Cowra, New South Wales, 2794, Australia Actual Inventor(s): Edward Charles Fagan Address for Service: Spruson & Ferguson St Martins Tower Level 35 31 Market Street Sydney NSW 2000 (CCN 3710000177) Invention Title: A lettuce harvester Associated Provisional Application Details: [33] Country: [31] Appl'n No(s): [32] Application Date: AU 2008902420 15 May 2008 The following statement is a full description of this invention, including the best method of performing it known to me/us: 5845c(2058842_1) 1 A LETTUCE HARVESTER Technical Field The present invention relates to harvesters to harvest plants and more particularly but not exclusively to harvest lettuce 5 Background of the Invention Lettuce is harvested by hand. This is achieved by workers severing the lettuce head from the root stock by means of a knife and placing the severed lettuce head in a container or leaving the lettuce head for collection. The above discussed method of harvesting lettuce is time consuming and 10 expensive with the problem being exacerbated by difficulty in getting staff to undertake manual harvesting. Object of the Invention It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages. is Summary of the Invention There is disclosed herein a harvester to harvest a plurality of plants growing in a soil layer having an upper surface, each plant having a head portion above said surface and a root portion embedded in said layer, the harvester having: a chassis to move over said surface in a forward direction at a desired speed; 20 ground engaging means operatively associated with the chassis and to engage said surface to propel said chassis in said direction at said speed; a blade supported on said chassis and located thereon so as to be positioned adjacent said surface to engage the plants to severe the head portions from the root portions; 25 a conveyor having a forward part and a rearward part, the forward part being located adjacently behind said blade to receive the severed head portions to convey the severed head portions to said rear part; and 2 a head portion engaging device supported by said chassis so as to be positioned adjacent said blade to engage the plant head portions to assist the blade in severing the head portions from the root portions and to aid in directing the severed head portions to said conveyor. 5 Preferably, said device has a forward part to engage the plant head portions and positioned forward of said blade in said direction. Preferably, said conveyor is a first conveyor, and said device is a second conveyor, with the second conveyor being positioned approximately above the first conveyor, with the conveyors converging rearwardly relative to said direction. 10 Preferably, said first conveyor is mounted on said chassis for angular movement about a generally horizontal axis to provide for height adjustment of the first conveyor forward part. Preferably, said harvester includes a third conveyor, said third conveyor having a lower end to receive the severed head portions from the first and second conveyors, an is upper end from which the severed head portions are delivered. Preferably, said second conveyor includes an elongated flexible element arranged in a loop, and a plurality of flanges projecting from the element so that when the flanges are adjacent said first conveyor, the flanges project towards the first conveyor. Preferably, said harvester includes a height adjustment arrangement to adjust the 20 height of said blade and said conveyors relative to said chassis. Preferably, said blade is longitudinally elongated and extends generally transverse of said direction so as to extend generally parallel to said surface. Preferably, said blade is horizontally reciprocated so as to move transversely of said direction. 25 Preferably, said harvester includes a duct to which an airstream is delivered and through which the severed head portions pass to separate loose material from the severed head portions, said duct receiving the severed head portions from said upper end. Preferably, said harvester includes a fourth and a fifth conveyor, the fourth and fifth conveyors being generally parallel and transversely spaced and extending in said 30 direction and positioned to receive the severed head portions from said duct.

3 Preferably, said harvester includes a sixth conveyor, said sixth conveyor extending generally transverse relative to said direction and positioned to receive the severed head portions from said fourth and fifth conveyors for delivery of the severed head portions to a storage means. 5 Preferably, said harvester includes a control mechanism operatively associated with the first and second conveyors so that the first and second conveyors each have a peripheral speed approximately equal to said desired speed. Brief Description of the Drawings A preferred form of the present invention will now be described by way of 10 example with reference to the accompanying drawings wherein: Figure 1 is a schematic side elevation of a lettuce harvester; and Figure 2 is a schematic top plan view of the harvester of Figure 1. Detailed Description of the Preferred Embodiment In the accompanying drawings there is schematically depicted a lettuce harvester 15 10. The lettuce harvester 10 passes over a soil layer 12 having an upper surface 11. Growing in the soil layer 12 is a plurality of lettuce 13, the lettuce 13 being hard core lettuce having a head 14 joined to root stock 15 by means of a base 16. The harvester 10 includes a chassis 17 that includes a plurality of wheels or tracks 18 of which some are driven so as to propel the harvester 10 forward in a direction 20 19 at a preferred velocity. Preferably the wheels 18 are arranged in pairs so that the harvester 10 straddles a number of rows of lettuce 13, the rows extending in the direction 19. Attached to the forward end of the chassis 17 is a sub-frame 20 that includes a plurality of wheels 21 that roll along the surface 11 in the direction 19 as the harvester 10 25 is propelled. Supported by the sub-frame 20 is a blade 22. The blade 22 is driven by means of a motor 23. For example, the blade 22 may extend transversely relative to the direction 19 so as to span at least one row of lettuce 13 to cut the head portion 14 from the root stock 15 by severing the base 16. In one embodiment the blade 22 may be a single blade 4 member or alternatively a number of adjacent blades that are reciprocated in reverse directions. In alternative preferred forms, the blade 22 may be a plurality of blades that are caused to rotate by associated motors 23. The blade 22 is positioned relative to the surface 11 so as to engage each base 16. As the wheels 21 rest on the surface 11, and the s blades 22 arranged at a desired height relative to the wheels 21, the blade 22 is located to engage the bases 16 of the lettuce 13. Also mounted on the sub-frame 20 is a first conveyor 24. The first conveyor 24 includes an endless belt 25 that is formed of flexible material and is preferably provided by a cleated belt. The belt 25 is driven so that the upper length thereof moves in the 10 direction 26. The belt 25 passes between a pair of spaced rollers 27 having rotational axes that are generally horizontal, parallel and transverse of the direction 19. The conveyor 24 is supported on the sub-frame 20 for angular movement about the rotational axis of the rear roller 27 so that the forward roller 27 is adjustable in height together with the blade 22. This is achieved by operation of the hydraulic cylinder 66. Accordingly, is the forward end 67 of the conveyor 24 is height adjustable relative to the wheels 21 and the rear roller 27. The forward end 67 of the conveyor 11 is located adjacent but just rearward of the blade 22. The forward end 67 of the conveyor 24 is also positioned so as to be slightly above the blade 22 so as to receive each lettuce head 14 once it has been severed from the associated stem 16. 20 Located above the conveyor 24 and moved therewith is a further conveyor 28. The further conveyor 28 includes an endless belt 29 formed of flexible material. Extending from the belt 29 is a plurality of flanges 30, that extend away from the belt 29 so that the portion of the belt 29 facing the first conveyor 24 has the flanges 30 extending toward the conveyor 24. Preferably, the belt 29 has a forward length 31 that is 25 substantially parallel to the surface 11, and a second length 68 that is substantially parallel to the conveyor 24. The conveyor 28 has a forward end 32 that is located forward and at a higher position relative to the blades 22. The conveyor 28 has a rear end 33 terminating approximately above the rear roller 27. The conveyors 24 and 28 are spaced so that the lettuce heads 14 are located therebetween and conveyed in the direction 26. The belts 25 30 and 29 are driven so as to have a peripheral speed substantially the same as the speed of 5 the harvester 10 in the direction 19, with the lower length of the belt 29 also moving in the direction 26. The conveyors 24 and 28 have adjacent belt lengths that converge rearward. By operation of the hydraulic cylinder 66 the height of the forward portions of 5 the conveyors 24 and 28 together with the height of the blade 22 is adjustable relative to the sub-frame 20 and wheels 21. In particular the conveyors 24 and 28 and blade 22 are moved in unison so as to move angularly about the rotational axis of the rear roller 27. The flanges 31 engage the heads 14 of each lettuce 13 and aid in supporting the lettuce 13 while the blade 22 engages the base 16. Once the head 14 is severed, the io flanges 31 aid in directing the heads 14 to a position at which they are located between the conveyors 24 and 28 so as to be conveyed rearwardly thereby to a further conveyor 40. The conveyor 40 provides an endless belt 41 having an upper length 42 that receives the lettuce heads 14. The upper length 42 moves in the direction 43. The belt 41 also has a plurality of flanges 44 that engage the lettuce heads 14 to convey the lettuce heads 14 is from the lower end 44 to the upper end 45 of the conveyor 40. The sub-frame 20 is attached to the lower end of the conveyor 40 by means of a pair of parallel linkages and a hydraulic cylinder not illustrated. These parallel linkages provide for relative movement between the sub-frame 20 and the conveyor 40 within predetermined limits so that the conveyors 24 and 28 and blade 22 are located at a desired 20 height as the wheels 24 move over the surface 11. When being raised and lowered, the orientation of the conveyors 24 and 28, and blade 22 remains constant. However the conveyor 40 can be raised by operation of a hydraulic cylinder 68. The cylinder 68 causes angular movement of the conveyor 40 about the rotational axis of the roller 69 at the end 68. Accordingly when the conveyor 40 is raised the sub-frame 20 is raised 25 thereby removing the wheels 21 from engagement with the surface 11. This enables the conveyor 10 to be moved between locations, the wheels 21, and therefore the blade 22 and conveyors 24 and 28 raised to minimise the risk of damage during transport. Located adjacent the upper end 45 is an air duct 47 within which there is located a pair of rollers 48, the rollers 48 having axes 49 that extend generally horizontal and 30 transverse relative to the direction 19. Each roller 48 includes a plurality of axially 6 spaced radial discs 50, with the discs 50 radially overlapping between the axes 49. The duct 47 has an entrance opening 51 and a exit opening 52 via which the lettuce heads 14 enter and exit the interior of the duct 50. The rollers 48 are angularly driven to move the lettuce heads transversely across the interior of the duct 47. 5 The lower end of the duct 50 is provided with a fan 53 that is driven to create an airstream 54, the airstream 54 being directed so as to pass about and between the rollers 48 so as to remove from the lettuce heads 14 loose material such as outer leaves and any other debris that may have been delivered to the opening 51 by the conveyor 40. Heavier material such as soil passes downward of the duct 47 to exit via a chute 55. The upper 1o end of the duct 50 has a fan 71 that not only aids in creating the airstream 54, but also engages any leaf and other trash material passing thereby to be shredded. Accordingly, the fan 71 has blades that chop the leaf and trash material. The at least partly cleaned lettuce heads 14 are delivered to transverse horizontal conveyors 56 that convey the lettuce heads 14 in the directions 57 to deposit the lettuce 15 head portions 14 on further horizontal conveyors 58. The conveyors 58 are generally parallel and co-extensive. The conveyors 58 are operated to convey the lettuce heads 14 in the direction 59. Located between the conveyors 58 is a platform 60 upon which people stand or sit to sort the lettuce heads 14 passing thereby and remove any undesired material. Lettuce heads 14 that are to be kept are located on the far strips 61 while 20 material to be discarded is located on the adjacent strips 62 of the conveyor 58. The discarded material positioned on the strips 62 is delivered to exit chutes 63 from where it is discarded. The lettuce heads 14 to be retained are then delivered to a transverse conveyor 64 that deliver the lettuce heads 14 to a further conveyor 65 that raises the lettuce heads 14 to a desired height. From there the lettuce heads 14 are delivered to a 25 chute formed of soft sheet material such as fabric for delivery to a mobile storage container. The wheels 18 and 21 all have rotational axes transverse of the direction 19.

Claims (14)

1. A harvester to harvest a plurality of plants growing in a soil layer having an upper surface, each plant having a head portion above said surface and a root portion embedded in said layer, the harvester having: 5 a chassis to move over said surface in a forward direction at a desired speed; ground engaging means operatively associated with the chassis and to engage said surface to propel said chassis in said direction at said speed; a blade supported on said chassis and located thereon so as to be positioned adjacent said surface to engage the plants to severe the head portions from the root io portions; a conveyor having a forward part and a rearward part, the forward part being located adjacently behind said blade to receive the severed head portions to convey the severed head portions to said rear part; and a head portion engaging device supported by said chassis so as to be positioned is adjacent said blade to engage the plant head portions to assist the blade in severing the head portions from the root portions and to aid in directing the severed head portions to said conveyor.

2. The harvester of claim 1, further including a forward part to engage the plant head portions and positioned forward of said blade in said direction. 20

3. The harvester of claim 1 or 2, wherein said conveyor is a first conveyor, and said device is a second conveyor, with the second conveyor being positioned approximately above the first conveyor, with the conveyors converging rearwardly relative to said direction.

4. The harvester of claim 3, wherein said first conveyor is mounted on said 25 chassis for angular movement about a generally horizontal axis to provide for height adjustment of the first conveyor forward part.

5. The harvester of claim 3 or 4, further including a third conveyor, said third conveyor having a lower end to receive the severed head portions from the first and second conveyors, an upper end from which the severed head portions are delivered. 30

6. The harvester of claim 1 or 5, wherein said second conveyor includes an elongated flexible element arranged in a loop, and a plurality of flanges projecting from the element so that when the flanges are adjacent said first conveyor, the flanges project towards the first conveyor. 8

7. The harvester of any one of claims 1 to 5, further including a height adjustment arrangement to adjust the height of said blade and said conveyors relative to said chassis.

8. The harvester of any one of claims 1 to 7, wherein said blade is 5 longitudinally elongated and extends generally transverse of said direction so as to extend generally parallel to said surface.

9. The harvester of any one of claims 1 to 8, wherein said blade is horizontally reciprocated so as to move transversely of said direction.

10. The harvester of any one of claims I to 9, further including a duct to 10 which an airstream is delivered and through which the severed head portions pass to separate loose material from the severed head portions, said duct receiving the severed head portions from said upper end.

11. The harvester of claim 10, wherein appended to claim 5 further including a fourth and a fifth conveyor, the fourth and fifth conveyors being generally 15 parallel and transversely spaced and extending in said direction and positioned to receive the severed head portions from said duct.

12. The harvester of claim 11, further including a sixth conveyor, said sixth conveyor extending generally transverse relative to said direction and positioned to receive the severed head portions from said fourth and fifth conveyors for delivery of the 20 severed head portions to a storage means.

13. The harvester of any one of claims 3 to 6, further including a control mechanism operatively associated with the first and second conveyors so that the first and second conveyors each have a peripheral speed approximately equal to said desired speed. Dated

14 April, 2009 25 Mulyan Pty Ltd Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON