Automatic forage harvester knife sharpening system
AssigneeDeere & Company
InventorStanley J. Johnson
Life of this patent
Estimating the term…
Abstract
A material chapping machine, such as a forage harvester, includes a system for automatically controlling the movement of a sharpening stone to sharpen the knives of a rotating cutterhead. Motors move the stone radially towards and away from the cutterhead and laterally across the cutterhead. Contact between the stone and the cutterhead is sensed by knock sensors. The motors are controlled by a programmed microprocessor.
Claims11
In a material chopping machine having a rotatable cutterhead carrying a plurality of knives and a sharpening stone, a stone positioning system comprising:
- positioning means coupled to the stone for moving the stone towards and away from the cutterhead;
- sensor means for sensing accoustic signals produced by impact between the stone and the knives, the sensor means comprising a first knock sensor and a second knock sensor;
- and
- a control unit for controlling actuation of the positioning means, the control unit comprising means for automatically causing the positioning means to move the stone towards the cutterhead and for automatically limiting operation of the positioning means in response to the sensor means sensing accoustic signals representative of contact between the stone and the cutterhead knives, the control unit comprising means for comparing signals generated by the first and second knock sensors to separate low and high threshold levels and for automatically causing the positioning means to move the stone away from the cutterhead if the signal from one knock sensor exceeds the high threshold while the signal from the other knock sensor is less than the low threshold.
In a material chopping machine having a rotatable cutterhead carrying a plurality of knives and a sharpening stone, a stone positioning system comprising:
- positioning means coupled to the stone for moving the stone towards and away from the cutterhead;
- sensor means for sensing accoustic signals produced by impact between the stone and the knives;
- and
- a control unit for controlling actuation of the positioning means, the control unit comprising means for automatically causing the positioning means to move the stone towards the cutterhead and for automatically limiting operation of the positioning means in response to the sensor means sensing accoustic signals representative of contact between the stone and the cutterhead knives, the control unit further comprising means for changing a value in a first counter when the signal from the sensor means exceeds a first threshold, means for changing a value in a second counter when the signal from the sensor means exceeds a second threshold, and means for generating a signal representative of contact between the stone and the knives if either of the first and second counters attain a certain value.
In a material cutting machine having a rotatable cutterhead carrying a plurality of knives and a sharpening stone, an automatic cutterhead sharpening system comprising:
- position means for moving the stone radially towards and away from the cutterhead;
- sweep means coupled to the stone and operable to laterally move the stone back and forth across the cutterhead;
- and
- a control unit for automatically controlling the actuation of the position and sweep means so that the stone moves to sharpen the knives, the control unit including means for automatically varying the operation of the position means depending upon the number of times the stone is moved laterally by the sweep means.
In a material chopping machine having a rotatable cutterhead carrying a plurality of knives and a sharpening stone, an automatic sharpening system comprising:
- position means for moving the stone radially towards and away from the cutterhead;
- sweep means coupled to the stone for moving the stone laterally across the cutterhead;
- a control unit coupled to the sensor and to the position and sweep means for automatically controlling the actuation of the position and sweep means to sharpen the cutterhead knives, the control unit including means for monitoring an operating time period of an operation of the sharpening system, and for automatically moving the stone away from the cutterhead to a park position if the operating time period exceeds a limit time period.
In a material chopping machine having a rotatable cutterhead carrying a plurality of knives and a sharpening stone, a stone positioning system comprising:
- positioning means coupled to the stone for moving the stone towards and away from the cutterhead;
- sensor means for sensing accoustic signals produced by impact between the stone and the knives;
- and
- a control unit for controlling actuation of the positioning means, the control unit comprising means for automatically causing the positioning means to move the stone towards the cutterhead and for automatically limiting operation of the positioning means in response to the sensor means sensing accoustic signals representative of contact between the stone and the cutterhead knives, the control unit further comprising means for automatically terminating operation of the positioning means if the positioning means operates to move the stone towards the cutterhead for at least a certain time period without the sensor means sensing contact between the stone and the cutterhead.
Dependencies are inferred from the claim text.