Agricultural tool with electronically controlled downpressure system
First Claim
1. An agricultural tool for mounting on a tool bar, the tool bar being operatively carried on or attached to a tractor, which comprises:
- (a) a unit that performs an action on a farm field to change a state of the farm field as the unit is moved over the farm field;
(b) a linkage for movably mounting the unit on the tool bar for up and down movement of the unit relative to the farm field;
(c) a system for applying downpressure to the unit to maintain the unit in a desired operational position relative to the ground, wherein the downpressure system comprises;
(i) an air operated air shock that combines a downpressure air bag and a shock absorber, the air shock having first and second telescopic portions, wherein the first portion of the shock is attached to the tool bar and the second portion of the shock is attached to the linkage, the shock being extensible and contractible in length dependent upon a pressure level of the air inside the shock;
(ii) a source of pressurized air;
(iii) at least one valve between the source of pressurized air and the shock for supplying pressurized air to the shock or for removing the pressurized air from the shock; and
(iv) an electronic controller connected to the valve for automatically operating the valve as the unit is moved over the farm field to add and remove as need be the pressurized air to the shock in a feedback control loop to substantially maintain the length of the shock at a predetermined length to establish and maintain a desired downpressure on the unit, further including a sensor in operative communication with the controller for sending to the controller an output signal that is representative of an actual downpressure on the unit, wherein the controller comprises a storage device for storing a reference output signal that corresponds to the desired downpressure on the unit, and wherein the controller further comprises;
a user selectable setting for establishing an output signal change threshold comprising how far the output signal must vary from the reference output signal before the controller takes corrective action in the feedback control loop; and
a user selectable setting for establishing an output signal time threshold comprising how long the output signal change threshold must be continuously present before the controller takes corrective action in the feedback control loop.
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Accused Products
Abstract
An agricultural tool for a tractor tool bar comprises a unit, such as a planter unit, that includes a ground contacting member for performing a working operation on the ground for changing the state of the soil, such as by opening a furrow to receive a seed from the planter unit. A downpressure system for the tool includes a two part telescopic air shock extending between the tool bar and a parallelogram linkage that attaches the unit to the tool bar. A sensor is operatively connected to the portion of the air shock that is attached to the parallelogram linkage for sending a signal representative of the length of the shock to an electronic controller. The controller operates through a feedback loop to attempt to maintain the air shock at a predetermined length which corresponds to a desired amount of downpressure.
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Citations
8 Claims
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1. An agricultural tool for mounting on a tool bar, the tool bar being operatively carried on or attached to a tractor, which comprises:
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(a) a unit that performs an action on a farm field to change a state of the farm field as the unit is moved over the farm field; (b) a linkage for movably mounting the unit on the tool bar for up and down movement of the unit relative to the farm field; (c) a system for applying downpressure to the unit to maintain the unit in a desired operational position relative to the ground, wherein the downpressure system comprises; (i) an air operated air shock that combines a downpressure air bag and a shock absorber, the air shock having first and second telescopic portions, wherein the first portion of the shock is attached to the tool bar and the second portion of the shock is attached to the linkage, the shock being extensible and contractible in length dependent upon a pressure level of the air inside the shock; (ii) a source of pressurized air; (iii) at least one valve between the source of pressurized air and the shock for supplying pressurized air to the shock or for removing the pressurized air from the shock; and (iv) an electronic controller connected to the valve for automatically operating the valve as the unit is moved over the farm field to add and remove as need be the pressurized air to the shock in a feedback control loop to substantially maintain the length of the shock at a predetermined length to establish and maintain a desired downpressure on the unit, further including a sensor in operative communication with the controller for sending to the controller an output signal that is representative of an actual downpressure on the unit, wherein the controller comprises a storage device for storing a reference output signal that corresponds to the desired downpressure on the unit, and wherein the controller further comprises; a user selectable setting for establishing an output signal change threshold comprising how far the output signal must vary from the reference output signal before the controller takes corrective action in the feedback control loop; and a user selectable setting for establishing an output signal time threshold comprising how long the output signal change threshold must be continuously present before the controller takes corrective action in the feedback control loop. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification