Patent ID: 7392123

Claim:
A method for detecting a broken shear bolt supporting one end of a concave of a threshing apparatus of an agricultural combine, wherein the threshing apparatus has a rotor, wherein the rotor has an axis of rotation, wherein the concave has a pin on another end of the concave, the pin allowing pivotal rotation of the concave about an axis of rotation of the pin, wherein the axis of rotation of the pin is offset from the axis of rotation of the rotor, comprising the step of: coupling a position sensor to the pin for determining a pivotable position of the concave about the axis of rotation of the pin; and determining a rate of change of the pivotable position of the concave about the axis of rotation of the pin and comparing the determined rate of change to a predetermined rate of change value and, if the determined rate of change exceeds the predetermined value, then determining that a broken shear bolt condition exists, wherein if it is determined that a broken shear bolt condition exists, then outputting a signal representative thereof.