Method and apparatus for separating potatoes from stones and soil clods

Claim 1

The apparatus for sorting and separating potatoes from stones and soil clods which comprises: segregating conveyor means locatable adjacent the potato flow path of a potato harvester in position to receive the harvested mixture of potatoes, stones and soil clods therefrom, said conveyor having the conveying surface thereof shaped to define a plurality of longitudinally extending parallel troughs separated by upstanding ridges, said troughs cooperating with one another and with the ridges therebetween to channel the mixture into separate lines having the individual elements thereof moving one-at-a-time toward the discharge end; a transversely extending radiant energy source positioned adjacent the discharge end of the segregating conveyor adapted to radiate an uninterrupted band of both visible and infrared energy down atop each element of the mixture in each line; a sorting gate located at the discharge end of each trough in position to intercept each element of the mixture issuing therefrom, said gate having two operative positions each adapted to deflect the elements impinging thereagainst along a different path; optical means including a beam splitter positioned and adapted to gather the radiant energy reflected from each element in each line of the mixture and divide same into two discreet beams; first filter meanS positioned and adapted to intercept the radiant energy in one of said beams and pass only that energy within the band that extends from the red down into the infrared-near-red end of the spectrum; second filter means positioned and adapted to intercept the radiant energy in the other of said beams and pass only that energy within that band of the invisible spectrum that extends down from the infrared-near-red into the longer wave length infrared; discriminating means having a bridge with a pair of photo cell sensors connected therein, one of said sensors being positioned to intercept the filtered energy passing the first filter means and the second photo cell being positioned to intercept the filtered energy passing the second filter means, said bridge circuit being operative when connected to a D.C. power supply to compare the relative reflectances within the selected band widths of each element sensed in terms of the relative conductances of the photo cells and generate a signal whenever the ratio of said conductances exceeds a predetermined value; and, means connected to each sorting gate operative to shift the position thereof in response to a signal generated within the discriminator means associated therewith.

Claim 2

The apparatus for sorting and separating potatoes from stones and soil clods which comprises: segregating conveyor means locatable adjacent the potato flow path of a potato harvester in position to receive the harvested mixture of potatoes, stones and soil clods therefrom, said conveyor having the conveying surface thereof shaped to define a plurality of longitudinally extending parallel troughs separated by upstanding ridges, said troughs cooperating with one another and with the ridges therebetween to channel the mixture into separate lines having the individual elements thereof moving one-at-a-time toward the discharge end; a transversely extending radiant energy source positioned adjacent the discharge end of the segregating conveyor adapted to radiate an uninterrupted band of both visible and infrared energy down atop each element of the mixture in each line; a sorting gate located at the discharge end of each trough in position to intercept each element of the mixture issuing therefrom, said gate having two operative positions each adapted to deflect the elements impinging thereagainst along a different path; optical means including a beam splitter positioned and adapted to gather the radiant energy reflected from each element in each line of the mixture and divide same into two discreet beams; first filter meanS positioned and adapted to intercept the radiant energy in one of said beams and pass only that energy within the band that extends from the red down into the infrared-near-red end of the spectrum; second filter means positioned and adapted to intercept the radiant energy in the other of said beams and pass only that energy within that band of the invisible spectrum that extends down from the infrared-near-red into the longer wave length infrared; discriminating means having a bridge with a pair of photo cell sensors connected therein, one of said sensors being positioned to intercept the filtered energy passing the first filter means and the second photo cell being positioned to intercept the filtered energy passing the second filter means, said bridge circuit being operative when connected to a D.C. power supply to compare the relative reflectances within the selected band widths of each element sensed in terms of the relative conductances of the photo cells and generate a signal whenever the ratio of said conductances exceeds a predetermined value; and, means connected to each sorting gate operative to shift the position thereof in response to a signal generated within the discriminator means associated therewith.

Claim 10

The method for sorting and separating potatoes from stones and soil clods which comprises: channeling the mixture of potatoes, stones and soil clods into a plurality of parallel lines where the elements of said mixture can be examined one at a time, passing each element of the mixture beneath a source of radiant energy encompassing a band width that includes at least the red end of the visible spectrum on down through a substantial portion of the infrared end of the invisible spectrum, collecting the radiant energy reflected from each individual element of the mixture and dividing same into two discreet beams, filtering one of said beams so as to include only red through infrared-near-red energy and the other of said beams so as to include the remainder of the reflected infrared energy, sensing the energy reflected from each element within the selected bands and comparing the relative magnitudes thereof, and initiating a sorting function predicated upon the differences in relative reflectance magnitudes within said selected bands.

Claim 11

The method for sorting and separating potatoes from stones and soil clods which comprises: channeling the mixture of potatoes, stones and soil clods into a plurality of parallel lines where the elements of said mixture can be examined one at a time, passing each element of the mixture beneath a source of radiant energy encompassing a band width that includes at least the red end of the visible spectrum on down through a substantial portion of the infrared end of the invisible spectrum, collecting the radiant energy reflected from each individual element of the mixture and dividing same into two discreet beams, filtering one of said beams so as to include only red through infrared-near-red energy and the other of said beams so as to include the remainder of the reflected infrared energy, sensing the energy reflected from each element within the selected bands and comparing the relative magnitudes thereof, and initiating a sorting function predicated upon the differences in relative reflectance magnitudes within said selected bands.