Crop harvesting machine including retractable sensor fingers with adjustable ground pressure and header tilt control

Patent metadata

Field	Value
Publication number	US-11272660-B2
Application number	US-201916591212-A
Country	US
Kind code	B2
Filing date	Oct 2, 2019
Priority date	Mar 28, 2017
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A crop harvesting machine with a cutter bar on a header frame has a height control system which uses depending sensor fingers arranged in contact with the ground so as to measure a height of the cutter bar above the ground. The sensor fingers are controllably retractable under actuation from an operator in the cab or automatically in response to prescribed conditions being met. The actuator used in retracting the sensor fingers can also be used to adjustably control ground pressure of the sensor fingers in the deployed position of the sensor fingers engaging the ground. The header height is adjusted using laterally spaced apart hydraulic linkages which can be operated at different elevations relative to one another responsive to different height signals relating height of opposing ends of the header frame relative to the ground to also control tilt of the header relative to the harvester frame.

First claim

The invention claimed is:

1. A crop harvesting machine comprising:
a harvester frame having longitudinally opposed first and second ends supported for movement across ground having a crop thereon to be harvested;
a drive system mounted on the harvester frame for propelling the harvester frame in one of a plurality of drive conditions across the ground;
a cab mounted on the harvester frame for an operator;
a header mounted at the first end of the harvester frame comprising a header frame with a main rear frame member and a plurality of forwardly extending frame members each supported by the main rear frame member, and an elongate cutter bar connected to the forward end of the forwardly extending frame members so as to be arranged along a front edge of the header frame for cutting the crop;
a height control system for controlling a height of the header relative to the ground, the height control system comprising:
a sensor assembly arranged to determine height of the cutter bar above the ground, the sensor assembly including (i) a sensor finger which is elongate between a top portion of the finger pivotally supported on the header and a bottom portion of the finger distal from the top portion which is operable in a working position in which the finger depends from the top portion below the header frame to the bottom portion of the finger which is spaced below the header frame for engaging the ground and following contours of the ground and (ii) a position sensor arranged to generate an output signal corresponding to the height of the header relative to the ground based upon a position of the sensor finger;
a lift linkage operable between the header frame and the harvester frame to raise and lower the header frame relative to the harvester frame responsive to the output signal of the position sensor to position the cutter bar at a prescribed height; and

a sensor positioning assembly operatively coupled between the sensor finger and the header including an actuator operable to control a downward pressure of the sensor finger on the ground according to a set point pressure within a range of downward pressures in the working position.

2. The crop harvesting machine according to claim 1 further comprising a controller arranged to controllably adjust the set point pressure.

3. The crop harvesting machine according to claim 2 wherein the set point pressure is automatically controlled by the controller responsive to a height of the header frame.

4. The crop harvesting machine according to claim 1 wherein the set point pressure is controllable by an operator control in the cab.

5. The crop harvesting machine according to claim 1 further comprising:
the sensor finger being movable between the working position and a raised position in which said bottom portion of the sensor finger is in close proximity to the header frame;
the sensor assembly including a biasing member to bias the sensor finger towards one of the raised position and the working position, and
the actuator being operable to produce a biasing force acting against the biasing member to position the sensor finger in another one of the raised position and the working position.

6. The crop harvesting machine according to claim 5 wherein the actuator is responsive to a lift signal from the controller to displace the sensor finger from the working position to the raised position.

7. The crop harvesting machine according claim 5 wherein the biasing member acts to urge the sensor finger towards the raised position and the actuator acts to urge the sensor finger towards the working position.

8. The crop harvesting machine according to claim 1 wherein the actuator of the sensor positioning assembly is a hydraulic actuator and the downward pressure is controlled by using a controller to control a hydraulic pressure supplied to the actuator from a hydraulic supply on the harvester frame.

9. The crop harvesting machine according to claim 8 wherein the hydraulic supply is operable to vary the prescribed pressure supplied to the actuator throughout a range of pressures in the working position to maintain engagement of the sensor finger with the ground through a range of heights of the header frame relative to the ground.

10. The crop harvesting machine according to claim 8 further comprising:
a spring acting to urge the sensor finger towards a raised position;
the hydraulic actuator acting to urge the sensor finger towards the working position; and
the controller being arranged to reduce the prescribe pressure supplied by the hydraulic supply to the actuator to a reduced pressure corresponding to a force applied to the sensor finger by the actuator being exceeded by a force applied to the sensor finger by the spring for raising the sensor finger to the raised position.

Assignees

• Macdon Ind Ltd

Inventors

• Lacy Nolan
• Otto Philip
• Barnett Neil

Classifications

• A01D41/145

  Header lifting devices · CPC title

• A01D34/04

  with cutters at the front · CPC title

• A01D41/141 Primary

  Automatic header control · CPC title