Lettuce harvester

Claim 2

Harvesting apparatus comprising: vehicle mounting means; a frame; link means movably connecting said frame with said mounting means; knife means on said frame for severing mature lettuce at a butt end location generally adjacent the ground; sensing means on said frame for actuating said knife means between said sensing means and the ground immediately therebelow in response to crop density and size; lifting means on said frame for conveying said severed lettuce from the ground for subsequent handling; said knife means and said sensing means and said lifting means cooperating to select and harvest only those lettuce heads having a predetermined density and size.

Claim 3

The apparatus according to claim 1 wherein said frame includes: ground engageable skid means for accurately positioning said knife means relative to the ground; and said knife means being mounted on said skid means.

Claim 4

The apparatus according to claim 1 wherein said sensing means includes arm means for supporting said sensing means; substantially cylindrical opposed rollers rotatably mounted adjacent one end of said arm means, said arm means including spacing means biasing said rollers toward each other, and switch means on said arm means for actuating said knife means in response to movement of said rollers apart from each other a distance greater than a predetermined distance.

Claim 5

A crop harvesting device comprising: frame means having mounting means adjacent one end thereof for attachment to a vehicle and having a second end thereof adjustable generally vertically relative to the ground for supporting said crop harvesting device; sensing means secured to said second end for evaluating crop size and firmness; knife means extensible from said second end in a plane generally parallel to said ground and actuated by said sensing means to sever said crop between said sensing means and said ground immediately therebelow; and lifting means connected to said second frame end for conveying said severed crop for subsequent handling.

Claim 6

A crop harvesting device comprising: frame means having mounting means adjacent one end thereof for attachment to a vehicle and having a second end thereof adjustable generally vertically relative to the ground for supporting said crop harvesting device; sensing means secured to said second end for evaluating crop size and firmness; knife means extensible from said second end in a plane generally parallel to said ground and actuated by said sensing means to sever said crop between said sensing means and said ground immediately therebelow; and lifting means connected to said second frame end for conveying said severed crop for subsequent handling.

Claim 7

A vehicle mounted lettuce harvesting apparatus comprising: adjustable connecting means secured to said vehicle for supporting said harvesting apparatus; skid means attached to said connecting means and having a ground engageable surface on the lower side and a support surface on the upper side; knife means mounted on said support surface and including a knife extensible generally horizontally to the ground and outwardly from a position above said skid means for cleanly cutting the lettuce at its root; said knife being pivotally mounted to said skid means and swinging outwardly in a direction of vehicle travel; frame means attached to said connecting means and movable with said skid means; a sensing apparatus mounted on said frame means, said sensing apparatus comprising substantially cylindrical opposed roller means mounted adjacent a first end of said frame means for movement toward and away from one another to allow said lettuce to pass therebetween; said roller means being biased toward one another with a constant force; means for rotating said roller means at ground speed and in a direction of machine travel with facing surfaces thereof moving rearwardly; means for pivoting said knife in response to the movement of said roller means apart from each other a predetermined distance; endless conveyor belt means spaced generally parallel from one another and rotating about a frame attached to said connecting means for grasping severed lettuce heads therebetween; means for driving said belt means at ground speed and with facing surfaces thereof moving upwardly, and adjustment means for aligning said conveyor belt means with the lettuce growing positions.

Claim 8

A vehicle mounted lettuce harvesting apparatus comprising: adjustable connecting means secured to said vehicle for supporting said harvesting apparatus; skid means attached to said connecting means and having a ground engageable surface on the lower side and a support surface on the upper side; knife means mounted on said support surface and including a knife extensible generally horizontally to the ground and outwardly from a position above said skid means for cleanly cutting the lettuce at its root; said knife being pivotally mounted to said skid means and swinging outwardly in a direction of vehicle travel; frame means attached to said connecting means and movable with said skid means; a sensing apparatus mounted on said frame means, said sensing apparatus comprising substantially cylindrical opposed roller means mounted adjacent a first end of said frame means for movement toward and away from one another to allow said lettuce to pass therebetween; said roller means being biased toward one another with a constant force; means for rotating said roller means at ground speed and in a direction of machine travel with facing surfaces thereof moving rearwardly; means for pivoting said knife in response to the movement of said roller means apart from each other a predetermined distance; endless conveyor belt means spaced generally parallel from one another and rotating about a frame attached to said connecting means for grasping severed lettuce heads therebetween; means for driving said belt means at ground speed and with facing surfaces thereof moving upwardly, and adjustment means for aligning said conveyor belt means with the lettuce growing positions.

Claim 9

A sensing apparatus for use in vehicle mounted crop harvesting device comprising: frame means for supporting said sensing apparatus; substantially cylindrical opposed roller means rotatably mounted adjacent a first end of said frame means for moving relative to one another when said crop passes therebetween. means for driving said roller means at ground speed and in a direction of machine travel with facing surfaces thereof moving rearwardly; and means responsive to the movement of said roller means relative to each other for cutting a mature crop between said roller means and the ground immediately therebelow.

Claim 10

A sensing apparatus for use in vehicle mounted crop harvesting device comprising: frame means for supporting said sensing apparatus; substantially cylindrical opposed roller means rotatably mounted adjacent a first end of said frame means for moving relative to one another when said crop passes therebetween. means for driving said roller means at ground speed and in a direction of machine travel with facing surfaces thereof moving rearwardly; and means responsive to the movement of said roller means relative to each other for cutting a mature crop between said roller means and the ground immediately therebelow.

Claim 11

The sensing apparatus according to claim 6 wherein said frame means includes: biasing means for applying a constant force urging said roller means toward one another.

Claim 12

The sensing apparatus according to claim 7 wherein said frame means further includes: a pair of outwardly projecting frame members extending adjacent from said vehicle; pivot means associated with each of said frame members at a second end thereof; and adjustment means cooperating between said frame members adjacent said first end thereof for normally separating said rolLer means against bias by a predetermined distance.

Claim 13

The sensing apparatus according to claim 8 wherein said roller means hang downwardly from said frame and comprise rubber coated steel rollers.

Claim 14

The sensing apparatus according to claim 9 further including: switch means responsive to the separation of said rollers beyond said predetermined distance for signalling the selection of a mature crop; actuator means responsible to said switch means for pivoting a crop cutting knife.