Patent ID: 7520111
Filing Date: 2009-04-21
Classification: A01D,A01F

Abstract:
1. Apparatus for detecting hard objects in a flow of cut crop material softer than the hard objects flowing along a flow path between harvesting apparatus of an agricultural harvesting machine and threshing apparatus thereof, comprising: a detector element disposed along the flow path and configured such that flows of crop material along the flow path will contact the detector element to generate vibrations thereof, and such that at least some of any hard objects in the flows of crop material that contact the detector element will generate vibrations thereof at least generally within a first frequency band and a second frequency band having amplitudes greater than amplitudes of vibrations generated by the crop material alone; at least one vibration sensor operable for sensing vibrations of the detector element and responsively outputting signals representative thereof over a first signal path and a second signal path; the first signal path including a high pass filter operable for filtering the signal outputted over the first signal path to suppress frequencies thereof below a first frequency within or below a lower portion of the first frequency band to create a first frequency filtered signal, a high frequency bandpass filter operable for filtering the first frequency filtered signal so as to pass frequencies thereof generally within the first frequency band as a first bandwidth filtered signal, and a device operable for selectively outputting the first bandwidth filtered signal when the first bandwidth filtered signal is representative of vibrations having the amplitudes greater than the amplitudes of vibrations generated by the crop material alone; and the second signal path including a low frequency bandpass filter operable for filtering the signal outputted thereover so as to pass frequencies thereof within the second frequency band, and a device operable for selectively outputting the second bandwidth filtered signal when representative of vibrations having the amplitudes greater than the amplitudes of vibrations generated by the crop material alone.