Height control for agricultural machine

An agricultural machine for field use where it is important to keep a machine member at a substantially constant height above the field, including in combination:

• a wheel-supported main frame,
• an auxiliary frame carrying said machine member and supported by said main frame for generally vertical movement relative thereto,
• lifting-and-lowering means for lifting said auxiliary frame and said machine member therewith relative to said main frame,
• first transducer means for determining the position of said machine member relative to said main frame and developing a first electrical signal corresponding thereto,
• ultrasonic distance-determining means secured to an underside of said auxiliary frame above and spaced from said machine member and having a housing with the ultrasonic electrostatic second transducer connected to an electronic transmitter and to an electronic receiver, for determining ultrasonically the height of said second transducer above the field and for generating a second electrical signal corresponding thereto,
• setting means on said main frame for setting said machine member at an initial position relative to the surface of said field, from which initial position the actual relative position of said machine member diverges due to such things as field surface roughness,
• electronic calculation means electrically connected to said first and second transducer means and provided with trigonometric and other constants relating to the geometry of said auxiliary frame, its mounting to said main frame, its said lifting-and-lowering means, said machine member, and the location of said receiver, for determining the amount and direction of divergence of said actual position of said machine member relative to the field surface from its initial position relative thereto and producing an electrical correction signal corresponding thereto, and
• correcting means responsive to said correction signal for actuating said lifting-and-lowering means and thereby bringing said actual position toward conformity with said initial position.

A tomato harvester for use in a tomato field wherein tomato plants are grown in rows along a series of elevated beds, each bed lying between a pair of furrows, including in combination:

• a wheel-supported main frame,
• a header frame pivotally supported by said main frame generally forward thereof,
• plant-stem-severing means at the forward and lowest edge of said header frame,
• plant pickup and elevating means on said header frame behind said plant-stem-severing means and extending upwardly and rearwardly therefrom,
• header-lifting means having a first power means connected to said main frame and to said header frame for swinging said header frame up in a vertical plane relative to said main frame, return being by gravity,
• first transducer means for determining the position of said header frame relative to said main frame and developing a first electrical signal corresponding thereto,
• ultrasonic distance-determining means secured to an underside of said header frame above and to the rear of said plant-stem-severing means and having electrostatic, ultrasonic, second transducer means, for determining ultrasonically the height of said receiver above the bed and for generating a second electrical signal corresponding thereto,
• a gauge frame pivotally supported by said header frame,
• a pair of gauge wheels rotatably supported on opposite sides of said gauge frame forward of the header frame, for riding in a pair of furrows between which a bed lies,
• gauge-frame-lifting-and-lowering power means mounted to said header frame and said gauge frame for swinging said gauge frame in a vertical plane relative to said header frame,
• means for placing said header frame in a free-floating condition during operation so that the gauge-frame-lifting-and-lowering power means determines the height of the header frame above ground and also relative to the main frame,
• electrically actuated means for controlling said gauge-frame-lifting-and-lowering power means for thereby raising and lowering of header frame relative to said gauge wheels when said gauge wheels ride on the ground in said furrows,
• setting means on said main frame acting on both said gauge-frame-lifting-and-lowering means for setting the plant-stem-severing means at a desired height relative to said gauge wheels and thereby initially setting said plant-stem-severing means at a desired level relative to the surface of a said bed,
• electronic calculation means electrically connected to said first and second transducer means and provided with trigonometric and other constants relating to the relative positions of said header frame with its pivot, the header-lifting-and-lowering means, the plant-stem-severing means, and said receiver, for determining the divergence between the actual position of said plant-stem-severing means relative to the bed surface and its desired position relative thereto and producing an electrical correction signal corresponding thereto, and
• correcting means responsive to said correction signal for actuation of said solenoid valve for bringing said actual position toward conformity with said desired position.

A tomato harvester for use in a tomato field wherein tomato plants are grown in rows along a series of elevated beds, each bed lying between a pair of furrows, including in combination:

• a wheel-supported main frame,
• a header frame pivotally supported by said main frame generally forward thereof for swinging movement in a vertical plane relative to said main frame,
• a header-lifting first fluid power device having a first cylinder pivoted to said main frame and a first piston inside said cylinder with a first rod pivoted to said header frame,
• first valve means for supplying actuating fluid to said first fluid power device for lifting said header, return being by gravity upon release of said first valve means, said first valve means having a detented position placing the header frame in a free-floating condition,
• first transducer means for determining the position of said first piston in said first cylinder and developing a first electrical signal corresponding thereto and therefore to the position of said header frame relative to said main frame,
• a gauge frame pivotally supported by said header frame generally forward thereof for swinging movement in a vertical plane relative to said header frame,
• a gauge-frame-lifting-and-lowering second fluid power device having a second cylinder pivoted to said header frame and a second piston inside said second cylinder with a second rod pivoted to said gauge frame,
• a pair of gauge wheels rotatably supported on opposite sides of said gauge frame forward of the header frame, for riding in a pair of furrows between which a bed lies,
• second valve means for supplying actuating fluid to said second fluid power device and thereby raising and lowering said header frame relative to said gauge wheels when said gauge wheels ride on the ground in said furrows,
• solenoid means for operating said second valve means according to electrical energization of said solenoid means,
• control means for placing said first valve means in its said detented position so that said header is in a free-floating condition and said second power device determines the height of said header frame relative to the ground and to said main frame,
• plant-stem-severing means at the forward and lowest edge of said header frame,
• plant pickup and elevating means on said header frame behind said plant-stem-severing means and extending upwardly and rearwardly therefrom,
• distance-determining means secured to an underside of said header frame above and to the rear of said plant-stem-severing means and having a housing with electrostatic, ultrasonic, second transducer means, for determining ultrasonically the height of said receiver above the bed and for generating a second electrical signal corresponding thereto,
• setting means on said main frame acting on said second fluid power means for setting the plant-stem-severing means at an initial height of said plant-stem-severing means relative to said gauge wheels determined by a desired position of the plant-severing means relative to the surface of a said bed, said desired position thereafter necessarily tending to diverge from the actual position as the bed and furrows diverge from being perfectly level,
• electronic calculation means connected electrically to said first and second transducer means and provided with trigonometric and other constants relating to the geometry of said header frame with respect to its pivot, its first fluid power device, its plant-stem-severing means, and its said receiver, for determining the difference and direction of divergence of the actual position of said plant-stem-severing means relative to the bed surface from its desired position relative thereto and producing an electrical correction signal corresponding thereto, and
• correcting means responsive to said correction signal for actuating said solenoid means and thereby actuating said second valve means for causing said second fluid power means to bring said actual position into closer conformity with said desired position.

A tomato harvester for use in a tomato field wherein tomato plants are grown in rows along a series of elevated beds, each bed lying between a pair of furrows, including in combination:

• a wheel-supported main frame having a pivot point,
• a header supported by said pivot for swinging movement in a vertical plane relative to said main frame, said header having a frame, plant-stem-severing means at its forward and lowest edge, and plant pickup and elevating means extending upwardly and rearwardly from said plant-stem-severing means,
• a header-lifting first fluid power device pivoted at one end to said main frame and at its other end to said header frame and having a first cylinder and a first piston inside said cylinder with a first rod,
• first valve means for supplying actuating fluid to said first fluid power device for lifting, return being by gravity, said first valve means having a detented position in which said header is in a free-floating condition,
• first transducer means for determining the position of said fist piston in said first cylinder and developing a first electrical signal corresponding thereto and therefore to the positions of said plant-stem-severing means relative to said pivot,
• distance-determining means secured to an underside of said header frame above and to the rear of said plant-stem-severing means and having a housing with electrostatic, ultrasonic, second transducer means, for determining ultrasonically the height of said receiver above the bed and for generating a second electrical signal corresponding thereto,
• a gauge frame pivotally supported for swinging movement in a vertical plane relative to said header frame,
• a pair of gauge wheels rotatably supported on opposite sides of said gauge frame forward of the header frame, for riding in a pair of furrows between which a bed lies,
• a gauge-frame-lifting-and-lowering second fluid device having a second cylinder pivoted to said header frame, a second piston inside said second cylinder having a second rod pivoted to said gauge frame,
• solenoid valve means for supplying actuating fluid to said second fluid device and thereby effectuating raising and lowering of said header frame relative to said gauge wheels when said gauge wheels ride on the ground in said furrows,
• control means on said main frame acting on said first valve means for placing it in its detented positon and on said second valve means for intitially setting the height of said plant-stem-severing means relative to said gauge wheels,
• electronic calculation means electrically connected to said first and second transducer means and provided with trigonometric constants relating to the geometry of said header with its pivot, its first fluid device, its plant-stem-severing means, and the location of said receiver, for determining the divergence between the actual position of said plant-stem-severing means relative to the bed surface and a desired position relative thereto and producing an electrical correction signal corresponding thereto, and
• correcting means responsive to said correction signal for actuating said solenoid valve and thereby bringing said plant severing means into closer conformity with its said desired position.