Lettuce harvesting apparatus and method therefor

A mobile harvesting apparatus and method, which permits the automated harvesting of produce, preferably lettuce. The apparatus consists in its most basic form of a vehicle having a bandsaw positioned at a front portion thereof, the blade of which is positioned to slice the lettuce head at the desired location. The apparatus further includes a conveyor, that transports the harvested produce from the cutting site and onto the apparatus. Preferably, the apparatus additionally features a washing conveyor, washing station, inspection station, and elevator conveyor, to assist in the further processing of harvested produce.

FIELD OF INVENTION

This invention relates generally to apparatuses and methods for harvesting produce and, more specifically, to a mobile lettuce harvester adapted to permit the automated harvesting of lettuce heads.

BACKGROUND OF THE INVENTION

Generally, the harvesting of produce, including in particular lettuce, involves the manual removal of produce from the field. Typically, a farmworker will walk through a field with a cutting tool such as a knife, and manually detach the exposed lettuce head from its root. The lettuce head will then be delivered for further processing, perhaps to a conveyor belt on a self-propelled harvester travelling through the field alongside the worker.

There are several drawbacks with the prior art methods, however. They are labor-intensive and, because of the use of a sharp cutting implement by the workers, potentially dangerous. A need therefore existed to reduce the labor-intensity of the produce harvesting process, and also to make that process safer. Preferably, account should also be taken of other steps necessary in the harvesting process beyond the removal of the produce from the ground, including inspection, washing, and elevation of the produce to a container. The present invention satisfies this need and provides other, related advantages.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a mobile harvester permitting automated harvesting of produce, including specifically lettuce.

It is a further object of the present invention to provide a mobile harvester permitting automated harvesting of produce, and further having a conveyor belt, a washing station, and an elevator belt.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with one embodiment of the present invention, a self-propelled harvester is disclosed. The harvester comprises, a mobile harvesting apparatus traveling on a plurality of wheels and powered by an engine, a bandsaw having an exposed cutting blade positioned at a front portion of the apparatus wherein the level of the cutting blade may be adjusted by a leveling feature, and a conveyor for conveying the harvested produce.

In additional embodiments, the harvester may further comprise a washing station, shaking means for shaking excess water from the harvested produce, an inspection area, and additional conveyors.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first toFIG. 1, an embodiment of the lettuce harvesting apparatus10(“apparatus10”) of the present invention is shown. The apparatus10is intended to be used for the harvesting of produce. It is preferred to use the apparatus10to harvest lettuce, and in particular romaine lettuce.

The major components of the apparatus10include a bandsaw12, a feed conveyor14, a lift conveyor16, a washing conveyor18, a washing station20, a transfer conveyor22, and an elevator conveyor24. The apparatus10is powered by an engine26, rides on wheels28, and may be driven by a person29sitting in driving compartment30.

The bandsaw12is positioned at the front of the apparatus10as shown inFIGS. 1-4. The exposed cutting blade15of the bandsaw12is positioned at the base of the feed conveyor14. The height of the bandsaw12and thus of the exposed cutting blade15is preferably adjustable, and the desired height setting will depend on the specific produce to be cut. Generally, with romaine, the height of the exposed cutting blade15will be set between 0.25″ and 1.5″ from the ground. The level of the bandsaw12, and thus of the exposed cutting blade15, is preferably also adjustable, as herein described.

Preferably, the bandsaw12further comprises a housing17, which conceals the cutting blade15after it passes across the area where it will be cutting the produce, and continues to loop upward and around. (The path of the cutting blade15is illustrated inFIG. 4.) The purpose of the housing17is to increase safety for persons who might be working with the apparatus10. The bandsaw12is preferably powered hydraulically, though of course other powering means may be employed.

The feed conveyor14is coupled to the lift conveyor16with coupling arms32, which coupling arms32are to travel in an upward and downward direction about the point at which they couple to the lift conveyor16. The feed conveyor14preferably rides on five parallel rollers34(only one is shown), with the rollers34being positioned about axle35and with axle35being coupled at each end thereof to a substantially L-shaped member37. Each substantially L-shaped member37rotates about point B, and is coupled at its second end (the first end being coupled to axle35) to a hydraulic cylinder13(only one of which is shown). (It should be understood that fewer than five, or more than five, rollers34could be provided, and further that they could be positioned in a non-parallel configuration.) It is further preferred to position scrapers (not shown) above each roller34, oriented so as to remove dirt or debris that adheres to the surface of the rollers34as the apparatus10travels through a field to be harvested.

The feed conveyor14is coupled to the coupling arms32with first vertical supports36and second vertical supports38. The first vertical supports36include a spring and shock assembly40thereon, so as to permit upward and downward movement of the front portion of the feed conveyor14, as indicated by the bi-directional arrow, in response to variations in the terrain over which the apparatus10travels.

The second vertical supports38are rotatably coupled below the surface of the feed conveyor14about point A, which is a centrally-located universal joint. As the front of the feed conveyor moves upward or downward—either by operation of the herein-described height adjustment mechanism or in response to terrain variations—the feed conveyor is permitted to rotate about points A and B. This permits the feed conveyor14to remain relatively stable during operation.

The entire feed conveyor14preferably maintains a generally upward angle, as indicated in FIG.1. The belt42of the feed conveyor14travels in an upward direction, so as to move harvested produce from the front of the feed conveyor14upward toward the lift conveyor16.

Turning now to the lift conveyor16, as shown inFIGS. 1 and 2, it is preferably oriented in an upward direction, when viewed moving backward along the apparatus10from the feed conveyor14. The feed conveyor14is preferably oriented at about a 45 degree angle. The belt44of the feed conveyor14preferably has a plurality of outwardly projecting steps46. The purpose of the steps46is to prevent the produce from falling backward as it is moved upward along the lift conveyor16.

The lift conveyor16is preferably slidably retained on a frame11on the main body of the apparatus10, and may be raised or lowered along the frame11by activation of a hydraulic cylinder (not shown). Raising or lowering of the lift conveyor16along the frame11will also cause the feed conveyor14to be raised or lowered as well, by virtue of the herein-described coupling of the feed conveyor14to the lift conveyor16. In this manner, it is possible to raise or lower the exposed cutting blade15, so as to position it at the desired height for optimum cutting.

For purposes of describing the levelling feature of the apparatus10, attention is now drawn to hydraulic cylinders13(only one of which is shown), which couple between axle35and the substantially L-shaped member37. When it is desired to adjust the horizontal level of the exposed cutting blade15, typically because of the terrain of the area to be harvested, such levelling can be accomplished by the individual extension or contraction of the hydraulic cylinders13, which will have the effect of rotating the substantially L-shaped members37about point B and thereby raising or lowering the side of the feed conveyor14proximate the activated hydraulic cylinder13.

When the produce reaches the topmost point of the lift conveyor16, it will pass to the washing conveyor18. As the produce moves along the washing conveyor18, it will pass through a washing station20. Referring now toFIG. 1, the washing station20in one embodiment consists of a plurality of spray nozzles21located above the washing conveyor18, so as to spray water downward onto the produce passing below. Referring now toFIG. 3, the washing station20in another embodiment consists of a plurality of spray nozzles21located above the washing conveyor18and a plurality of spray nozzles21located below the washing conveyor18. In this embodiment, the produce is sprayed from above and below. (In the embodiment shown inFIG. 3, the belt48will need to be configured so as to permit the passage of water therethrough, such as by forming holes in the belt48. The water sprayed through the spray nozzles21is preferably stored in water tank50.

Referring now toFIG. 1, in one embodiment, a portion of the washing conveyor18may be left exposed from the top thereof, so as to permit one or preferably two persons29to be positioned there. From that position, the persons29may inspect the produce as it passes along the washing conveyor18, for purposes of quality control. Alternatively, or in combination with the inspection step, one or more persons29could remove harvested produce (or a portion of harvested produce—e.g., the heart or the leaves) from the washing conveyor18for packaging. (It should be noted that it would also be possible to position the exposed portion after the washing station20.)

Referring now toFIG. 3, in one embodiment, a plurality of shaker bars52are positioned below the belt48, and oriented so that movement of the shaker bars52causes shaking of the belt48. This shaking movement will cause some of the water remaining on the produce after its passage through washing station20to be removed. Referring now toFIGS. 1 and 3, from the end of the washing conveyor18, the produce will pass to a transfer conveyor22, which is preferably oriented at a right angle to the washing conveyor18. The transfer conveyor22will move the produce to the elevator conveyor24. Like the lift conveyor16, the elevator conveyor24preferably has a plurality of outwardly projecting steps46thereon so as to prevent the produce from falling backward as it travels upward. At the terminus of the elevator conveyor24, at exit point B, the produce is dumped into a receptacle (not shown), which may be a truck bed or other suitable vessel.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention. For example, it may be possible to operate the feed conveyor14with the bandsaw12as a stand-alone unit, so as to achieve the advantage of automated cutting of the produce—and then performing the washing and loading steps separately. Moreover, the feed conveyor14and lift conveyor16could be combined into a single conveyor. Still further, it would be possible to eliminate the transfer conveyor22, and instead to configure the elevator conveyor24in combination with the steps46so that produce could pass directly from the washing conveyor18to the elevator conveyor24without falling backward. Yet further, it would be possible to eliminate both the transfer conveyor22and elevator conveyor24, with dumping of the produce taking place at the terminus of the washing conveyor18.