Automatic forage harvester shearbar adjusting
AssigneeDeere & Company
InventorStanley J. Johnson
Life of this patent
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Abstract
An automatic forage harvester shearbar-cutterhead clearance adjusting system includes motors connected to conventional left and right shearbar adjusting mechanisms. A knock sensor senses contact between the shearbar and the rotating knives of the cutterhead. A control unit including a programmed microprocessor controls the motors and, responding to signals from the knock sensors, automatically adjusts the shearbar-cutterhead clearance. The control unit prevents machine damage by responding to various fault conditions.
Claims4
In a material processing machine having a rotatable cutterhead and a shearbar adjacent thereto for processing material introduced therebetween, acoustic sensor means for sensing contact between he cutterhead and the shearbar, a mechanism for moving the shearbar towards and away from the cutterhead and a control system cooperating with the acoustic sensor means and with the mechanism to automatically adjust clearance between the cutterhead and shearbar, characterized by:
- the acoustic sensor means comprising first and second spaced-apart knock sensors fixed to the shearbar, each generating signals in response to vibrations received thereby;
- and
- means operable during adjustment of the shearbar-cutterhead clearance for comparing the signal from the first knock sensor to a first threshold, for comparing the signal from the second knock sensor with a second threshold, and for preventing clearance adjustment if either knock sensor signal exceeds its threshold while the other knock sensor signal is less than its threshold.
In a material processing machine having a rotatable cutterhead and a shearbar adjacent thereto for processing material introduced therebetween, acoustic sensor means for generating a signal representing vibration of the shearbar, a mechanism for moving the shearbar towards and away from the cutterhead and a control system cooperating with the acoustic sensor means and with the mechanism to automatically adjust clearance between the cutterhead and shearbar, characterized by:
- means for repetitively sampling the sensor signal, for determining a portion of a certain time period during which the sensor signal exceeds a predetermined threshold, and for generating a knock signal representing contact between the cutterhead and shearbar when the determined portion of the certain time period exceeds a reference time period;
- means for sensing rotation of the cutterhead;
- and
- means for establishing the length of the certain time period as a function of the rotation of the cutterhead.
Dependencies are inferred from the claim text.