US3750881A - Color sorter - Google Patents

Abstract

A color sorter which sorts products delivered in single file to a photoelectric scanning head by directing acceptable products into an accept chute and diverting products which do not match the color standard for the product into a reject chute designed and shaped to deflect the rejected products into reject bins and minimize reentry of deflected products into the accept chute.

Description

I United States Patent 11 1 1111 3,750,881 Husome et al. [4 1 Aug. 7, 1973 COLOR SORTER 2,858,018 10/1958 Alexander 209 74 R 2,929,500 3/l960 W n r 209/HL6 [75] Inventors: Robert G. Husome, Saratoga; John 3,034,645 5/1962 g 209/74 R x k Sunnyvale, both of 3,275,130 9/1966 Allen 209/74 R Cahf.

[73] Assignee: Aerotherm Corporatlon, Mountain Primary Examiner-Richard A. Schacher View, Calif. Att0rneyFlchr, Hohbach, Test, Albritton and Herbert [22] Filed: Sept. 30, 1971 1211 Appl. No.: 185,292 [571 ABSTRACT A color sorter which sorts products delivered in single 52 08. c1. 209/74 R 209/11 1.6 a P scanning head by dimming [Sl] Int. Cl. i307c 5/342 ceptabie Products acccPt chute and diverting [58] Field of Search 209/72 74 111.6 P which do match the standard the 20,9 product into a reject chute designed and shaped to deflect the rejected products into reject bins and mini- [56] References Cited mize reentry of deflected products into the accept UNITED STATES PATENTS chute" 2,726,762 12/1955 Aubry 209/11 1.6 5 Claims, 6 Drawing Figures PATENTEDMJB Hm 3.750.881

SHEEI 1 Bf 3 F/6.'/ F Z Y REJECT ROBERT cs. HUSOME F/ 3 7 JOHN R. SWEET III INVENTORS BY 1442.4, 22 m- WM ATTORNEYS PATENIEDAUG 1 I875 ERT G. HUSOME N R. SWEET III INVENTORS ATTORNEYS PATENTEDAUG Hm 3.750.881

I sum 3 nr 3 22 PARTICLE r23 If 1W ROBERT G. HUSOME JOHN R. SWEET III F 6 INVENTORS BY 73%, W, M W5 V W ATTORNEYS COLOR SORTER This invention relates generally to sorters and more particularly to a reject-accept chutefor color sorters.

Generally, a color sorter includes a=hopperto which the product to be sorted is delivered'and a vibratory feeder which withdraws a product from the hopper and discharges the product on counter-rotating rollers. On the rollers, the product aligns itself into a single file and is accelerated to a high speed. At the end of the rollers, the. product passes through a scanninghead where=it is simultaneously inspected byphotoelectric devices. If the product is either darker or lighter than a preselected standardcolor, an air valve diverts the product into a reject chute. All products whichmatch the color standard aredirected to an accept'chute.

Because the particles are often of irregular shape, size and weight, the path taken by rejectedparticles varies considerably. Although all'rejected'particles are deflected away fromthe air valve nozzle, the amount of deflection varies considerably between particles. Furthermore, their irregular shape often causesthem to acquire a considerable upward or downward component of velocity as well. Because thepath of rejected particles is so poorly defined, alarge opening must:be provided in the side of the accept chute to assure passage of all rejected particles out of the chuteinto the reject chute. The velocity of these particles is high at normal sorting rates, between I50 and 500 inches per second. When they strike the walls of the reject chute, they rebound with high velocity. In prior chutes, a large enough percentage of rejected products rebounded back through the opening of the accept chute into the accept chute to limit the sorting efficiency.

OBJECTS AND SUMMARY OF THE INVENTION It is an object of the present invention to provide a color sorting apparatus having an improved acceptreject chute which minimizes bounce-back.

It is another object of the present invention to provide a color sorting apparatus including a reject-accept chute having curved side walls whereby rejected product having various trajectories is directed downwardly into the reject chute.

The foregoing and other objects of the invention are achieved by a color sorter apparatus in which the reject chute has a curved wall opposite the reject nozzle whereby the particles strike the surface of the chute at acute angles with predictable rebound paths which are directed away from the opening between the accept and reject chute through which they are deflected.

BRIEF DESCRIPTION OF THE DRAWING "DESCRIPT ION OF THE PREFERRED EMBODIMENT Referring now particularly to FIGS. 1, 2 and 3, there is shown a color sorting apparatus supported by stand 11. The apparatus includes a hopper 12 adapted to receive product to'be sorted, a vibratory feeder 13 which accepts the product from the hopper and delivers it to counter-rotating rollers 14. On the rollers, the product aligns itself into a single file and is accelerated under gravitational forces to high speed. At the end of the photomultiplier tubes, lenses and slits and color filters which are collectively used to measure the amount of light reflected from the background plate and the product as it passes through the scanning head. An electronic compartment 21 contains control circuits and a power supply which supplies regulated power to the illumination system, to photocells and to the control circuits. The control circuits interpret the electrical current received from the photocells and accept or reject the product under observation. In the event of reject, a reject impulse is delayed for a predetermined time giving the product time to move from the inspection position to the reject position opposite the reject nozzle 22, FIG. 4. The reject system is designed around an electrically operated air valve 23 which deflects the product in its free-fall trajectory to the accept chute. The rejected product is directed into a reject chute and then collected in a reject bin 24 while the accepted product travels down accept chute, into an accept bin Referring now more particularly to FIGS. 4, 5 and 6, the accept-reject assembly includes an accept tube or chute 26 which is inclined downwardly to receive undeflected product in its free-fall trajectory after leaving the inspection head. The accept tube 26 includes a channel portion 27. A cover portion 28 is hinged to the reject chute by hinges 29, 31 to cooperate with the sides of the channel to form an accept tube or chute. The side wall terminates short of the upper end of the channel to leave an opening 32 opposite the reject nozzle 21. The reject chute 33 includes a sloping or inclined lower wall 34 and a downwardly sloping or inclined upper wall 35. The upper wall 35 extends upwardly to the hinged cover 28. The: lower wall surface of the reject chute is angled at 45 so that rejected product strikes at an acute angle and is deflected downwardly into the reject chute rather than reflect back through the opening 32. In accordance with. the present invention, the top surface of the reject chute is de signed to assure that rejected particles will strike the surface at an angle of 45 more or less resulting in rebound which would direct them away from the opening 32 and downwardly into the reject chute. In the example shown, the top surface of the: reject chute is a curved piece of transparent plastic. Transparency is desirable to permit observing product being rejected while adjusting the controls. The shape of the curve assures particle approach angle of 45 or less as shown schematically in FIG. 6 where the particles are shown striking the upper curved surface and being deflected downwardly into the reject chute and away from the accept chute opening 32.

Thus, there is provided an improved color sorting apparatus in which it is assured that the particles do not reenter the accept chute.

We claim:

1. In a color sorter of the type in which products to be sorted pass in a single file past an inspection station and free fall past a rejection station where rejected product is deflected from the single file by an air blast from a nozzle, the improvement comprising an acceptreject chute having an accept portion in line with the single file of particles whereby undeflected particles travel through an accept chute and a reject chute opposite said nozzle adjacent the accept chute and extending downwardly at an angle with respect to said accept chute, said reject chute including a curved wall ooposite the reject nozzle whereby deflected products which strike said curved wall are deflected downwardly into the reject chute.

2. A color sorter as in claim 1 in which the accept chute is in the form of a tube having an opening opposite the air nozzle communicating with the reject chute whereby rejected product can be deflected out of the tube.

3. A color sorter as in claim 2 in which said reject chute has inclined upper and lower wall portions.

4. A color sorter as in claim 1 wherein said curved wall is hinged to the reject chute and forms a wall of the accept tube as well as of the reject chute.

5. A color sorter as in claim 4 wherein said curved wall is transparent.

k II I! i

Claims (5)

1. In a color sorter of the type in wHich products to be sorted pass in a single file past an inspection station and free fall past a rejection station where rejected product is deflected from the single file by an air blast from a nozzle, the improvement comprising an accept-reject chute having an accept portion in line with the single file of particles whereby undeflected particles travel through an accept chute and a reject chute opposite said nozzle adjacent the accept chute and extending downwardly at an angle with respect to said accept chute, said reject chute including a curved wall ooposite the reject nozzle whereby deflected products which strike said curved wall are deflected downwardly into the reject chute.

2. A color sorter as in claim 1 in which the accept chute is in the form of a tube having an opening opposite the air nozzle communicating with the reject chute whereby rejected product can be deflected out of the tube.

3. A color sorter as in claim 2 in which said reject chute has inclined upper and lower wall portions.

4. A color sorter as in claim 1 wherein said curved wall is hinged to the reject chute and forms a wall of the accept tube as well as of the reject chute.

5. A color sorter as in claim 4 wherein said curved wall is transparent.

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