US3009571A - Method of and apparatus for sorting articles - Google Patents

Description

METHOD OF AND APPARATUS FOR SORTING ARTICLES Filed May 5, 1958 5 Sheets-Sheet 1 INVENTOR THOMAS E. ROBERTS,JR.

ATTORNEY mvsn'ron moms E. Roasmsm BY M ATTORNEY Nov. 21, 1961 1-. E. ROBERTS, JR 3,009,571

METHOD OF AND APPARATUS FOR SORTING ARTICLES Filed May 5, 1958 5 Sheets-Sheet 3 IIIIIII'II'IIIIIIA INVENTOR F'IE EI ATTORNEY THOMAS E. ROBERTS,JR.

Nov. 21, 1961 T. E. ROBERTS, JR 3,009,571

METHOD OF AND APPARATUS FOR SORTING ARTICLES Filed May 5, 1958 5 SheetsSheet 4 AM AAA AAA AAA MA AAA AAA AAA vv vv II Iv Iv 1v '1 vv ATTORNEY METHOD OF AND APPARATUS FOR SORTING ARTICLES Filed May 5, 1958 Nov. 21, 1961 T. E. ROBERTS, JR

5 Sheets-Sheet 5 EN; MM

mm N Now 5 =I MON INVENTOR THOMAS E. ROBERT$,JR.

BY 5% /W ATTORNEY United States Patented Nov. 21, 1961 free 3,009,571 METHOD OF AND APPARATUS FOR SORTING ARTICLES Thomas E. Roberts, Jr., Saratoga, Calif., assignor to FMC Corporation, a corporation of Delaware Filed May 5, 1958, Ser. No. 732,884 24 Claims. (Cl. 209-1115) The present invention appertains to a method of and apparatus for sorting articles, and more particularly to a method of and apparatus for sorting articles such as rice, beans, peas or the like.

In the sorting of articles as to color or shade, it has been the practice to advance the articles in a single file or row past a color inspection station and to determine the surface luminosity of successive articles while they are traveling in a single file past said station. To increase the capacity of the machine it was necessary, heretofore, to advance a plurality of rows of articles through the machine and to increase the number of inspecting devices accordingly, with the resultant increase in size and cost of the machine.

Therefore, an object of the present invention is to provide an article sorting apparatus for sorting large quantities of articles in a relatively short time duration and, which, nevertheless, is comparatively compact.

Another object of the present invention is to provide an article sorting apparatus of relatively small size and eificient and dependable operation.

Another object is to provide an article sorting apparatus for sorting articles at rapid speeds without sacrificing accuracy or durability.

Another object of the present invention is to provide an improved method for sorting articles according to color by comparing the results attained by inspecting the surface luminosity thereof in different portions of the light spectrum.

Another object is to provide a method of sorting articles according to color wherein the articles are advanced continuously and successively in a plurality of paths within an annular inspection zone.

Other objects and advantages of the present invention will become apparent from the following description and drawings, in which:

FIG. 1 is a schematic vertical section of the article sorting apparatus of the present invention taken along the central axis thereof.

FIG. 2 is a horizontal section taken along line 2-2 of FIG. 1 to illustrate a dispensing chute for the article sorting apparatus of the present invention.

FIG. 3 is a fragmentary perspective of the dispensing chute.

FIG. 4 is a schematic diagram of the article sorting apparatus of the present invention.

FIG. 5 is a schematic vertical section of a modification of the article sorting apparatus of the present invention.

FIG. 6 is a horizontal section taken along line 6-6 of FIG. 5.

FIG. 7 is a schematic diagram of the electrical circuits employed in the article sorting apparatus shown in FIG. 5.

FIG. 8 is a schematic diagram of a further modification of the article sorting apparatus of the present invention.

As illustrated schematically in FIG. 1, the article sorting apparatus 10 of the present invention comprises a hopper 11 for receiving and dispensing articles having different colors or shades. The hopper 11 includes an outer cylindrical wall 12 and an inner cylindrical wall 13 for receiving and dispensing articles therebetween. A

suitable ventilating duct 14 is formed by the inner cylindrical wall 13. At the discharge end of the hopper 11 is disposed a stationary dispensing chute 15 having a generally conical configuration. The dispensing chute 15 includes a slanting surface 16, which may be of corrugated configuration to form a plurality of article feed channels 17 (FIGS. 2 and 3). The slanting surface 16 is spaced a predetermined distance below the outer wall 12 (FIG. 1) to permit a single uniform layer of the articles to advance in each channel and is disposed at a predetermined slope or pitch, as determined by its angle relative to a horizontal base member 18, to space sucessive articles in each channel at predetermined intervals, thereby controlling the rate of discharge of the articles from each feed channel. Articles advancing in each of the channels 17 upon reaching a lower peripheral edge 19 of the dispensing chute 15 Wall freely and successively in arcuate paths.

Positioned below the dispensing chute 15 is a stationary housing 30, which includes an annular top member 31 having its inner edge 32 disposed in spaced relation with the peripheral edge 19 of the dispensing chute 15 to form therebetween an annular opening 33. The annular opening 33 enables the articles discharged from the dispensing chute 15 to enter the housing 30. The top member 31 is supported by an outer cylindrical wall 35 which, in turn, is supported by an annular base member 36 adjacent the outer edge thereof. [An inner cylindrical wall 37 of the housing 30 includes a bottom flange 37' upon which the inner edge of the base number 36 rests.

The articles that enter the housing 30 from each of the channels 17 through the annular access opening 33 pass through an annular inspection zone A wherein the surface luminosity or the surface light reflecting properties of each article are individually determined for sorting. For illuminating the articles passing through the inspection zone A, a suitable light source in the form of an annular bank of incandescent lamps 38 is pro vided, which lamps are mounted on a standard 39 that is fixed to the inner cylindrical wall 37 of the housing 30. In order that the entire surface of each article passing through the inspection zone A be illuminated, an an= nular angularly disposed bafile 40 having an upper light reflecting and diffusing surface is secured to the cylindrical wall 35 at the lower portion of the inspection zone A and the under surface of the base member 18, which is positioned at the upper portion of the inspection zone A, is provided with a light reflecting and diflusing surface preferably of somewhat less efliciency in this respect than the baflle 40.

According to the present invention, each article that drops from the channel 17 through the inspection zone A is viewed by a rotatably mounted inspecting device 50, which is received within the hollow interior 51 of the inner cylindrical wall 37 of the housing 30. The inspecting device 50 includes a tubular shaft 52 that is jour nalled for rotation within the opening 51 by suitable bearings 53 and has its axis of rotation aligned with the vertex of the dispensing chute 15. A driven pulley 54 is secured to the shaft 52 and has trained therearound a suitable drive belt 55. The drive belt 55 is also trained around a drive pulley 56, which is secured to a shaft 57 of a continuously operated synchronous drive motor 58.

A viewing housing 59 is mounted on an outwardly projecting flange 60 of the tubular shaft 52 for rotation therewith. Mounted within the viewing housing 59 is an optical system 60' for receiving and transmitting light reflected from individual articles within the inspection zone A. The optical system 60' includes an objective lens 61, which is vertically disposed at the article viewing side of the housing 59. The lens 61 is so arranged that a plane x-x defined by the principal axis of the lens 61 when the inspecting device 50 is rotated passes through a central portion of the inspection zone A. Centrally mounted within the viewing housing 59 is a mirror 62 that is arranged to intercept the light passing through the lens 61 and to reflect the intercepted light downwardly through a horizontally disposed converging lens 63, which is mounted on the viewing housing 59 above the tubular shaft 52. The principal axis of the lens 63 and the plane xx intersect at a point that is located adjacent the center of the mirror 62.

Disposed below the converging lens 63 and fixed to the inner wall of the tubular shaft 52 so as to rotate therewith is an opaque disc 64 that has an aperture, preferably a narrow slit 65, located at the center thereof. The aperture 65 is in vertical alignment with the principal axis of the converging lens 63 and is of suitable size to permit only the light reflected from a restricted area of the central portion of the inspection zone A to pass therethrough, thus enabling the apparatus to inspect one article at a time. To direct the light from the lamps 38 to the inspection zone A and to prevent the lamps 38 from emitting light directly to the inspecting device 58, a frusto-conical shield 66 is carried by the standard 39 between the lamps 38 and the inspecting device 50.

Thus, articles are discharged continuously from the feed channels 17 of the dispensing chute through the annular access opening 33 into the annular inspection zone A. The articles from each channel 17, however, fall successively into the inspection zone A. Hence, a curtain of articles passes continuously through the inspection zone A. Centrally located within the housing and, therefore, centrally disposed within the annular inspection zone A is the continuously rotating inspecting device 50. The speed at which the inspecting device 50 rotates is commensurate with the rate at which articles enter the inspection zone A, which is controlled by the slope of the slanting surface 16 of the dispensing chute 15. Preferably, the viewing housing 59, which rotates with the inspecting device 50, is arranged to make one complete revolution during the interval of time that it takes for successive articles in one of the feed channels to enter the inspection zone A. In addition, the objective lens 61 mounted in the viewing housing 59 in its rotary movement receives light successively from adjoining portions of the inspection zone A. Articles discharged from each of the successive channels 17 fall freely through one of said portions of the inspection zone. The aperture 65 of the opaque plate 64 limits the reflected light from the inspection zone A to allow only one article to be viewed at a given time. Accordingly, the inspecting device 50 is arranged to view individually each article that passes through the inspection zone A.

In the exemplary embodiment of the present invention, the articles to be sorted are precooked grains of rice. Precooked grains of rice that are desirable from a commercial point of view have a fairly uniform white color, while grains of rice undesirable from a commercial point of view vary in degree of discoloration. Such discoloration often appears as black spots. I have discovered that improved results can be achieved for the separation of the undesirable rice from the desirable rice by detecting the light reflecting properties of the rice in a range of light having wave lengths from 480 to 680 millimicrons. It is to be noted, however, that other ranges of the light spectrum may be employed. A suitable filter 67 that passes light having wave lengths in the range from 480 to 680 millimicrons is disposed below the aperture 65 and is fixed to the inner wall of the tubular shaft 52.

For detecting the light reflecting properties or the surface luminosity of the inspected grains of rice and creating electrical signals respectively distinctive thereto, a suitable light responsive device, such as a photomultiplier tube 68, is employed. The photomultiplier tube 68 is mounted on a stationary platform 69. In order to detect discoloration of precooked rice grains that may vary in size, it is desirable to employ a reference background so that the reflected light is not a function of the size of the rice grain. For this purpose, an inner surface of the outer cylindrical wall 35 of the housing 30, which is located between the baffle 40 and the top member 31, is coated or otherwise colored to provide a suitable background, such as a White background. Hence, light is reflected from the background surface 80 as well as from the individual rice grain while the latter is viewed by the inspecting device 50. The inspecting device 50 transmits the reflected light to the photomultiplier tube 68, which generates an electrical signal having an amplitude commensurate with the degree of discoloration of the surface luminosity of the viewed rice grain with respect to the luminosity of the background surface 80.

Connected to the output of the photomultiplier tube 68 is a suitable amplifier 81 (FIG. 4), which in turn has the output thereof connected to a suitable pulsing circuit 82. The pulsing circuit 82 is designed to emit a pulse when the output of the photomultiplier tube 68 is of such an amplitude as to be representative of the degree of discoloration of an inspected rice grain that is undesirable. The output of the pulsing circuit 82 is connected to a rotatable brush or a radially projecting electrode 83 (FIG. 1), which includes a discharge end 84 and a base 85. The base 85 is fixedly mounted on the viewing housing 59 through an insulated post 86, which is disposed in alignment with the axis of rotation of the inspecting device 50. The discharge end 84 of the brush 83 projects in the same general direction as the objective lens 61. Hence, the rotation of the brush 83 is synchronized with the rotation of the inspecting device 50 and the discharge end 84 of the brush 83 is indexed for movement with the objective lens 61 of the inspecting device 50.

A stub shaft 87 of suitable conducting material is received by an aperture, not shown, formed in the base 85 of the brush 83 and is fixed to the brush for rotation therewith. A cap 88 made of suitable conducting material fits over the upper end of the shaft 87 and is arranged to permit the shaft 87 to rotate therein, while establishing an electrical connection therewith. Connected to the cap 88 is one end of a conductor 89 that extends to the exterior of the hopper 11 through a tubular sleeve 90 extending between the walls 12 and 13 of the hopper 11. The other end of the conductor 89 is connected to the output of the pulsing circuit 82 (FIG. 4). Thus, a pulse emitted from the pulsing circuit 82 is conducted to the brush 83 for establishing an electrical charge at the discharge end 84 thereof.

The base 86 of the brush 83 is disposed at the radial center of an annular spark commutator (FIGS. 1 and 4) and the discharge end 84 of the brush 83 is spaced a suitable distance from an inner cylindrical wall 111 of the spark commutator 110. The spark commutator 110, which is mounted on the base member 18 of the stationary dispensing chute 15 through an insulated bracket 113, is divided into a plurality of juxtaposed commutator segments 114 separated by suitable insulation. The number of commutator segments is equal to the number of feed channels 17. Hence, a commutator segment is associated with each of the feed channels 17 and is positioned adjacent its associated feed channel.

When the output of the photomultiplier tube 68 is of sufiicient amplitude to cause the pulsing circuit 82 to emit a pulse, the brush 83 is charged. The charge on the brush 83 is transferred to the commutator segment 114 aligned therewith at the time the pulse is emitted by the pulsing circuit 82. This transfer of an electrical charge from the brush 83 to the commutator segment 114 aligned therewith is in the form of a spark or brush discharge.

Connected to each of the commutator segments 114 is the grid circuit 115a of a suitable trigger tube 115,

which may be a thyratron tube or a cold cathode gas tube. The trigger tubes 1-15 are mounted in a bank on the top member 31 of the housing 30. In the plate circuit 11511 of each of the trigger tubes 115 are contacts 117 and a solenoid 116. The cathode circuit 1115c of each of the trigger tubes 115 is connected to ground. When the electrical charge is transferred from the brush 83 to the commutator segment 114 aligned therewith, the charge is of suflicient magnitude to cause the trigger tube 115 associated with the commutator segment 114 receiving the brush discharge to conduct. As a result, the solenoid 116 associated with the conducting trigger tube 115 is energized.

Mechanically linked with a plunger, not shown, of each of the solenoids 116 is a normally closed valve 118, which is included in a pipe line 119 interconnecting a suitable source of air under pressure in the form of a pump 120 and an article ejector in the form of an air nozzle 121. Each valve 118 and its associated nozzle 121 are associated with one of the feed channels 17 and are mounted on the top member 31 adjacent their associated channel 17 (FIG. 1). Each nozzle 121 is received by a suitable opening in the top member 31 and projects into the inspection zone A so as to be disposed adjacent the arcuate path of travel of articles dropping from its associated feed channel 17.

When a solenoid 116 is energized by the conduction of its associated trigger tube 115, the valve .118 mechanically linked to the energized solenoid is opened, thereby permitting the flow of compressed air into its associated nozzle 121. The compressed air flowing through the air ejector nozzle 121 deflects the inspected rice grain having the discoloration responsible for actuation of the solenoid 116 and ejects the same from the path of travel (FIG. 1) that it otherwise would follow.

Disposed below the inspection zone A are cylindrical baflles 130, 131, and 132, which are supported by the base member 36 of the housing 30. Inspected grains of rice having no discoloration are discharged from the dispensing chute 15 and continue in their path of travel (dotted line b of FIG. 1) through the inspection zone A to fall between the baflies 130 and 131, while inspected grains of rice showing discoloration are deflected into different paths of travel (dotted line of FIG. 1) through the inspection zone A by the air jets emitted by the nozzles 121. The deflected rice grains fall between the battles 131 and 132. Suitable discharge ports 133 and 134 are provided in the base member 36 of the housing 30 so' that the sorted articles can be received by separate receptacles, not shown.

To extinguish the conducting trigger tube 115 to prepare the same for its succeeding operation, the plunger, not shown, of the solenoid 116 associated with the conducting trigger tube is mechanically linked to the contacts'117. When the energized solenoid is operated, its associated contacts 117 are opened temporarily to open the plate circuit of the conducting trigger tube, thereby extinguishing the same.

In the operation of the article sorting apparatus shown in FIGS. 1-4, inclusive, precooked grains of rice are deposited into the hopper 11 and drop onto the dispensing chute 15, which distributes the grains of rice into a plurality of feed channels 17. The grains of rice advance in each feed channel in a single uniform layer and are spaced successively at predetermined intervals. As the grains of rice advancing in each feed channel reach the peripheral edge 19 of the dispensing chute 15, they fall freely and successively through the access opening 33 into the housing 30. The rice grains are discharged continuously fromthe feed channels 17.

The grains of rice that enter the housing 30 pass through the annular inspection zone A, where the entire surface of each falling rice grain is illuminated by the lamps 38. While in the inspection zone A, each rice grain is inspected individually by the continuously rotating inspecting device 50 which views the grain with the background 80. The light reflected from the inspected rice grain and that from the background are transmitted by the inspecting device 50 to the photomultiplier tube 68, which generates an electrical signal having an amplitude commensurate with the degree of discoloration of the surface luminosity of the inspected rice grain with respect to the background 80. When an inspected rice grain has a degree of discoloration that is undesirable from a commercial point of view, the output of the photomultiplier tube 68 is of suflicient amplitude to cause the pulsing circuit 82 to emit a pulse. Conversely, when a good rice grain is inspected, the output of the photomultiplier tube 68 is insufficient to cause the pulsing circuit 82 to emit a pulse.

When an undesirable grain of rice is detected, the pulsing circuit 82 charges the brush 83, which in turn transfers the change to the commutator segment 114 aligned therewith at the time the pulse is emitted. The potential on the charged commutator segment is of sufiicient magnitude to cause the trigger tube 115 associated therewith to conduct. As a result the solenoid 116 in the plate circuit of the conducting trigger tube is energized and opens the valve 118 mechanically linked therewith. In addition, the energized solenoid temporarily opens the plate circuit of the conducting trigger tube 115 through its associated contacts 117 to prepare the same for subsequent operations. The opening of valve 118 permits compressed air to flow into the air nozzle 121 associated with the feed channel from which the bad grain of rice was dropped. Thus, the compressed air flowing through the ejector nozzle 121 deflects the bad rice grain from its path of travel in the inspection zone A and the bad rice grain falls between baflles 131 and 132. Good rice grains are not deflected and continue in their path of travel in the inspection zone A to fall between the baflles and 131.

A modification of the article sorting apparatus 10 is illustrated schematically in FIGS. 5-7, inclusive. In describing the article sorting apparatus 200 shown in FIGS. 57, inclusive, the same reference numerals will be used for parts thereof that are similar to corresponding parts of the article sorting apparatus 10 (FIGS. 1-4, inclusive).

In the previously described articles sorting apparatus 10, the light reflecting properties of the precooked rice grains are viewed by the inspecting device 50 with the background 80 so that the light reflected will not be a function of the size of the grains. To detect the light reflecting properties of a rice grain that is not a function of the size of the rice grain and to do so without utilizing a background, the modified form 200 of the invention provides a color comparing system employing different portions of the color spectrum.

For this purpose, suitable light responsive devices such as photomultiplier tubes 201 and 202 (FIGS. 5 and 7) are provided, which are mounted within a stationary housing 203 that is disposed below the rotatable shaft 52 of the inspecting device 50. The housing 203 includes a suitably opening 204 located below the aperture 65 of the opaque plate 64 to receive the reflected light passing through the aperture 65. Mounted within the housing 203 and positioned below the opening 204 is a half-silvered mirror 205 that reflects a portion of the light admitted through the opening 204 to the photomultiplier tube 201. The remaining portion of the light admitted through the opening 204 passes through the half-silvered mirror 205 and is intercepted by a mirror 206, which is mounted in the housing 203 below the mirror 205. The mirror 206 is arranged to reflect the light passing through the halfsilvered mirror 205 to the photomultiplier tube 202. Mounted in the housing 203 between the photomultiplier tube 201 and the mirror 205'is a filter 207 that admits light of wave lengths in the range from 400 to 500 millimicrons. A filter 208 is mounted in the housing 203 and is positioned between the photomultiplier tube 202 and the mirror 206. The wave lengths of light passing through the filter 208 are in the range from 650 to 750 millimicrons. While other portions of the light spectrum may be utilized, -1 have found that improved results are achieved by employing light in the ranges having wave lengths from 400 to 500 millimicrons and from 650 to 750 millimicrons.

Referring to FIG. 7, the photomultiplier tubes 201 and 202 include cathodes 210 and 211, respectively, which are connected to a common source of negative potential (not shown) through a terminal 212. The photomultiplier tubes 201 and 202 also include anodes 213 and 214, respectively, which are connected to variable resistors 215 and 216, respectively. A source of positive potential, not shown, is connected to the variable resistors 215 and 216 through a terminal 217. The resistors 215 and 216 are adjusted so that when reflected light from a good rice grain is transmitted to the photomultiplier tubes 201 and 202, the output voltages from the photomultiplier tubes 201 and 202 are balanced or equal. A cathode follower 220 has its grid circuit 221 connected to the resistor 216, while a cathode follower 225 has its grid circuit 226 connected to the resistor 215. The output signal of the cathode follower 220, which is taken from its cathode circuit 227, is fed to a cathode 228 of a comparator tube 229 and the output signal of the cathode follower 225, which is taken from its cathode circuit 230, is fed to a grid 231 of the comparator tube 229. A suitable source of positive potential (not shown) is connected to the grid circuits 221 and 226 of the cathode followers 220 and 225, respectively, through a terminal 232.

The inspecting device 50 transmits the light reflected from individual rice grains to the photomultiplier tubes 201 and 202. Each time a grain of rice is inspected, the photomultiplier tube 201 generates an electrical signal having an amplitude representative of the surface luminosity of the scanned rice grain in the range of light wave lengths from 400 to 500 millimicrons, and at the same time the photomultiplier tube 202 generates an electrical signal having an amplitude representative of the surface luminosity of the same rice grain in the range of light wave lengths from 650 to 750 millimicrons. Since the output of the photomultiplier tube 201 is connected to the input of the cathode follower 225, the signal output of the cathode follower 225 is proportional to the output signal of the photomultiplier tube 201. The output of the photomultiplier tube 202 is connected to the input of the cathode follower 220 and, hence, the signal output of the cathode follower 220 is proportional to the signal output of the photomultiplier tube 202.

When a commercially desirable grain of rice is viewed by the inspecting device 50, the output signals of the photomultiplier tubes 201 and 202 will be substantially balanced. Hence, the voltages applied to the cathode 228 and the grid 231 of the comparator tube 229 through the cathode followers 220 and 225, respectively, will be of substantially equal potential. Therefore, the plate voltage of the comparator tube will be substantially constant. In case a commercially undesirable grain of rice is viewed by the inspecting device 50, the current flow in the photomultiplier tube 201 will be greater than the current flow in photomultiplier tube 202, and, consequently, the anode potential of the photomultiplier tube 201 will be more negative than the anode potential of the photomultiplier tube 202. Therefore, the output voltage of the cathode follower 225 is more negative than the output voltage of the cathode follower 220. As a result, the voltage impressed on the grid 231 of the comparator tube 229 is more negative than the voltage impressed on the cathode 228 of the comparator tube 229. Thus, the current flow through the comparator tube 229 is decreased and the positive potential on plate 241 of the comparator tube 229 is increased.

Connected to the comparator tube 229 is a multivibrator 250 that includes triode tubes 251 and 252. The tube 251 is normally biased to cut-01f and the tube 252 is normally conducting. The biasing potential for the tube 252 is produced across a cathode resistor 253, which is connected in common to the cathodes of tubes 251 and 252, respectively. A grid 254 of the tube 251 is connected to the plate 241 of the comparator tube 229. When the positive potential on the plate 241 is increased, in the manner previously described, the potential on plate 241 is of sulficient amplitude to overcome the bias on tube 251. As a result, the tube 251 will conduct and the tube 252 will be biased to cut-0E. When the multivibrator resets itself, i.e., when tube 251 is once again biased to cut-off and the tube 252 is once again conducting, a positive trigger pulse is emitted by the multivibrator 250. The maximum reset time of the multivibrator 250 is a function of a resistor 248 and a capacitor 249. The resistance- capacitance network 248 and 249 is so designed that the maximum reset time for the multivibrator 250 is greater than the time it takes for the brush 83 to travel the distance between like sides of adjacent commutator segments 114. In the present invention, however, the multivibrator 250 is reset to emit a positive trigger pulse before the maximum reset time has elapsed. This is accomplished through a synchronizer 257, which feeds a positive pulse to a grid 256 of the tube 252. The positive pulse emitted by the synchronizer 257 is adequate to make the tube 252 conduct, thereby once again biasing the tube 251 to cut-off. When this occurs, the multivibrator 250 transmits a positive trigger pulse over a conductor 255.

The synchronizer 257 comprises a timing disc 258 (FIGS. 5 and 6), which is mounted on the shaft 57 of the synchronous motor 58 for rotation therewith. Through this arrangement, the rotation of the timing disc 258 is synchronized with the rotation of the brush 83. The timing disc 258 includes a plurality of apertures 259 disposed adjacent the circumference thereof, which are spaced therearound at equal angular distances. The number of apertures 259 is equal to the number of commutator segments 114. A suitable lamp 261 is mounted below and adjacent one side of the timing disc 258 and is arranged to transmit light through an aperture 259 advancing thereabove. Adjacent the other side of the timing disc 258 is disposed a photoelectric tube 262 (FIGS. 5 and 7), which is arranged to conduct as each aperture 259 arrives in alignment therewith. An anode 263 of the photoelectric tube 262 is connected to a suitable source of positive potential, not shown, through a terminal 264, and a cathode 265 of the photoelectric tube 262 is connected to the grid circuit 256 of the tube 252, Which is part of the multivibrator 250. As each aperture 259 is aligned with the photoelectric tube 262, the photoelectric tube 262 conducts to apply a positive pulse to the grid circuit 256 of the tube 252.

The timing disc 258 is mounted on the shaft 57 of the synchronous motor 58 in such a manner that successive apertures 259 are aligned with the photoelectric tube 262 as the brush 83 is aligned with the central portion of successive commutator segments 114. In this manner, the multivibrator 250 is capable of emitting a trigger pulse in synchronism with the brush 83 being adjacent a central portion of each of the commutator segments 114. Therefore, the possibility of two adjacent commutator segments receiving a charge simultaneously is avoided. Of course, the multivibrator generator 250 emits a trigger pulse after the positive potential on the plate 241 of the comparator tube 229 is increased to cause the tube 251 to conduct and after the synchronizer 257 feeds a positive pulse to the tube 252 to reset the multivibrator 250. The article sorting apparatus 200 is capable of operating without the synchronizer 257. When the synchronizer 257 is omitted, the resistor 248 and the capacitor 249 will be designed to reset the multivibrator 250 in a relatively short time duration so that the multivibrator 250 will emit a positive trigger pulse substantially instantaneously with the conduction of the tube 251. As indicated above it is important that each commutator segment 114 receives its charge when the brush 83 is at the center of the segment rather than near the edge of the segment because in the latter position the brush might impart a charge to two adjacent segments. Also, it is apparent that after the multivibrator 250 has emitted a trigger pulse while brush 83 is at the center of a given segment 114, the multivibrator should not be reset while the brush remains on that segment, to avoid giving successive signals to the same segment. Thus it is desirable that the multivibrator not be reset until the brush reaches the gap between the segment that was just charged and the next segment. Under these optimum conditions, the reset time duration or delay will be substantially equal to the length of time it takes the brush 83 to move from the center of a segment 114, that has received a charge, to the gap between adjacent segments 114. The time that it takes the brush to cover this angle depends upon the speed of the motor 58 and the number of segments 114 provided. By way of example only, if the synchronous motor 53 is supplied with three phase 60 cycle alternating current, the motor will turn at 3600 rpm. At this speed of rotation, if there are 180 segments 114, it will take the relatively short time of about 100 micro-seconds for the brush 83 to move from the center of one segment 114 to the center of the neXt. The optimum re-set duration time or delay will then be about one-half of the above time, or about 50 micro-seconds.

A pulse generator 270 is connected to the multivibrator 250 through its grid circuit 271. The grid circuit 271 is connected to a suitable source of negative potential, not shown, through a terminal 272 and, thus, the pulse generator 270 is normally biased to cutoff. However, the pulse generator 278 is arranged to conduct and generate a pulse in response to the transmission of a trigger pulse from the multivibrator 250 over the conductor 255. A positive potential is impressed on the plate 273 of the pulse generator 270 through a terminal 274, which is connected to a suitable source of positive potential, not shown. Included in the plate circuit of the pulse generator 270 is a primary winding 275 of a phase inverting pulse transformer 276. A secondary winding 277 of the phase inverting pulse transformer 276 is connected in series with the brush 83.

When a commercially desirable rice grain is viewed by the inspecting device 50, the multivibrator 250 does not produce a trigger pulse. However, in case a commercially undesirable rice grain is viewed by the inspecting device 50, the multivibrator 250 produces a trigger pulse at the time the brush 83 is aligned with the central portion of the commutator segment 114 associated with the feed channel from which the discolored rice grain falls. The trigger pulse produced by the multivibrator 250 is suiticient to cause the pulse generator 270 to conduct, thereby producing a positive pulse in the secondary winding 277 of the phase inverting pulse transformer 276. The pulse produced in the secondary Winding 277 of the phase inverting pulse transformer 276 charges the brush 83 and the charge on the brush 83 is transferred to the commutator segment 114 having the central portion thereof aligned with the brush 83.

The commutator segments 114 are connected to the grids 115a of the aforementioned trigger tubes 115, respectively, and the plate circuits 11512 of the trigger tubes 115 have included therein the previously described solenoids 116, respectively. In the color sorting apparatus 10 (FIGS. 1-4, inclusive), a positive potential was applied to the plate circuits 11511 through a source of direct current (FIG. 4) to enable the tubes 115 to conduct when their associated commutator segments 114 were charged. The trigger tubes 115 were extinguished by breaking contacts 117 through mechanical linkage with the associated energized solenoids 116.

In the modified article sorting apparatus 200 (FIGS. 5-7, inclusive), the three phase synchronous motor 58 (FIG. 7) and primary windings 280, 281 and 282 of transformers 283, 284 and 285, respectively, are con- 10 nected to a source of three phase power through conductors 266, 267 and 268. Secondary windings 286, 287 and 288 of the transformers 283, 284 and 285, respectively, have center tap connections. Thus, the end terminals of the secondary windings 286, 287 and 288 and their center taps form a six phase network. One half of the trigger tubes 115, arranged consecutively, are divided into three consecutive groups of trigger tubes, and 'the tubes of each group are connected to the upper portions of the secondary windings 286, 287 and 288, respectively. The other one half of the trigger tubes, arranged consecutively, are also divided into three consecutive groups of trigger tubes, and the tubes of each group are connected to the lower portions of the secondary windings 286, 287 and 288, respectively. The groups of trigger tubes connected to the upper and lower portions, respectively, of the same secondary winding are oppositely located with respect to their location in the annular bank of trigger tubes. Through this arrangement, the plate circuits b of the trigger tubes 115 are sequentially and cyclically driven positive and negative in consecutive order. The windings are arranged so that each trigger tube 115 has impressed on its plate a positive potential at the time the brush 83 arrives at the commutator segment associated with the trigger tube.

When the electrical charge is transferred from the brush 83 to the commutator segment 114 associated with the feed channel from which the discolored rice grain falls, the charge is of suflicient magnitude to cause the trigger tube 115 associated with the commutator segment 114 receiving the brush discharge to conduct. As a result, the solenoid 116 associated with the conducting trigger tube 115 is energized. When the solenoid 116 is energized by the conduction of its associated trigger tube 115, the valve 118 (FIG. 5) mechanically linked to the plunger, not shown, of the energized solenoid is opened, thereby permitting the flow of compressed air into its associated nozzle 121. The compressed air flowing through the air ejector nozzle 121 deflects the in spected rice grain having a discoloration and ejects the same from the path of travel which it would have fol lowed. The conducting trigger tube 115 is extinguished when the negative potential portion of the voltage cycle is impressed on its plate circuit 115b through its associated secondary transformer winding, such as winding 286 that is coupled to the three phase power source (FIG. 7).

In the example of FIG. 7 only three tubes 115 are shown connected to each one of the center tapped secondary of transformers 280, in order to avoid complicating the drawings. Actually many more tubes 115 can be so connected. For example, if 30 tubes 115 were connected to each end of each secondary, this would provide for inspection channels, which, as mentioned previously, would give a traverse time between channels of about 100 micro-seconds with a 3000 rpm. drive motor. This speed is well within the capabilities of electronic devices. I

In the operation of the article sorting apparatus 200 (FIGS. 5-7, inclusive), precooked grains of rice are deposited into the hopper 11 and drop onto the dispensing chute 15, which distributes the grains of rice into a plurality of feed channels 17. Grains of rice advance in each feed channel in a single uniform layer and are spaced successively at predetermined intervals. As the grains of rice advancing in each feed channel reach the peripheral edge 19 of the dispensing chute 15, they fall freely and successively through the access opening 33 into the housing 30. The rice grains are discharged continuously from the feed channels 17.

The grains of rice that enter the housing 30 pass through the annular inspection zone A, where the surface of each falling grain is illuminated by the lamps 38. While in the inspection zone A, each rice grain is viewed individually by the continuously rotating inspecting device 50. As previously described, the inspecting device 50 is centrally located within the housing 30 and the objective lens 61 thereof in its rotary movement views successively portions of the inspection zone A having rice grains discharged thereinto from successive feed channels. The aperture 65 of the opaque plate 64 limits the reflected light from the inspection zone A to enable one rice grain to be inspected at a given time. A portion of the light passing through the aperture 65 is reflected to the photomultiplier tube 201 by the half-silvered mirror 205. The remaining portion of the light admitted through the aperture 65 passes through the half-silvered mirror 205 and is intercepted by the mirror 206, which transmits the intercepted light to the photomultiplier tube 202. The filter 207 limits the light admitted to the photomultiplier tube 201 to the wave lengths of light in the range from 400 to 500 millimicrons, while the filter 208 passes light for detection by the photomultiplier tube 202 of wave lengths in the range from 650 to 750 millirnicrons.

The photomultiplier tube 201 generates an electrical signal, each time a grain of rice is inspected, having an amplitude representative of the surface luminosity of the inspected rice grain in the light wave length range from 400 to 500 millimicrons, while the photomultiplier tube 202 generates an electrical signal, each time a grain of rice is viewed, having an amplitude representative of the surface luminosity of the inspected rice grain in the light wave length range from 650 to 750 millirnicrons.

When a commercially desirable grain of rice is viewed by the inspecting device 50, the outputs of the photomultiplier tubes 201 and 202 remain substantially balanced. Hence, the conduction of the comparator tube 229 is not altered substantially and no pulse is produced either by the multivibrator 250 or the pulse generator 270. Consequently, good rice grains are not deflected and continue in their path of travel in the inspection zone A to fall between the bafiles 130 and 131.

However, when a rice grain is inspected that has a degree of discoloration that is undesirable from a commercial point of view, more current will flow in the photomultiplier tube 201 than in photomultiplier tube 202. This results in a decrease of positive potential on the grid 231 of the comparator tube 229 relative to the potential on the cathode 228 of the comparator tube 229. Since the current flow in the comparator tube 229 decreases, the positive potential on the plate 241 thereof increases. The increase of positive potential on the plate 241 causes the tube 251 of the multivibrator 250 to conduct and the tube 252 of the multivibrator 250 to be biased to cut-off. The multivibrator 250 is reset to transmit a positive trigger pulse when the photoelectric tube 262 of the synchronizer 257 conducts to feed a positive pulse to the grid 256 of the tube 252, thereby causing the tube 252 to conduct and biasing the tube 251 to cut-off. This occurs when the brush 83 is adjacent the central portion of the commutator segment 114 associated with the feed channel from which the discolored rice grain falls. Therefore, the multivibrator 250 produces a trigger pulse at the time the brush 83 is properly oriented with the commutator segment 114 associated with the feed channel from which the discolored rice grain falls. The trigger pulse emitted by the multivibrator 250 is fed to the pulse generator 270, which charges the radially projecting brush 83 through the secondary winding 277 of the phase inverting pulse transformer 276. The brush 83 is disposed at the radial center of the annular spark commutator 110 and rotates in synchronism with the rotary inspecting device 50. The discharge end of the brush 83 is indexed for movement with the objective lens 61 of the inspecting device 50. The spark commutator 110 is divided into a plurality of juxtaposed commutator segments 114, there being a commutator segment for each feed channel.

When an undesirable grain of rice is detected, the brush 83 is charged, which in turn transfers the charge to the commutator segment 114 having the central portion there bf aligned with the brush 83. The potential on the 12 charged commutator segment is of sufficient magnitude to cause the trigger tube 115 associated therewith to conduct, since its plate has a positive potential impressed thereon at the time the brush 83 transfers the charge to the aligned commutator segment. As a result, the solenoid 116 in the plate circuit of the conducting trigger tube 115 is energized for opening the valve 118 (FIG. 5) mechanically linked therewith. The opening of the valve 118 permits compressed air to flow into the air nozzle 121 associated with the feed channel from which the bad grain was dropped. Thus, the compressed air flowing through the ejector nozzle 121 deflects the bad rice grain, causing it to fall between the baffles 131 and 132. The conducting trigger tube 115 is extinguished when the negative potential portion of the voltage cycle is impressed on its plate through its associated secondary transformer winding, such as winding 286, that is coupled to the three phase power source (FIG. 7).

A further modification of the article sorting apparatus of the invention is illustrated schematically in FIG. 8. In describing the article sorting apparatus 300 (FIG. 8), the same reference numerals will be used for parts thereof that are similar to corresponding parts of the article sorting apparatus 200 (FIGS. 57, inclusive). The electrical circuits (FIG. 7) described in connection with the article sorting apparatus 200 are employed in the article sorting apparatus 300 (FIG. 8).

In the previously described article sorting apparatus 200 (FIGS. 5-7, inclusive), the articles passing through the annular inspection zone A are illuminated by a bank of incandescent lamps 38 that are mounted within the housing 30. As shown in FIG. 8, the article sorting apparatus 300 does not include the bank of incandescent lamps, but does include a suitable source of incandescent light in the form of a prefocused lamp 301 that is received by the inner tubular portion 14 of the hopper 11. To support the lamp 301, a rigid tube 302 is secured to the base 303 of the iamp 301 and is received by the sleeve that extends between the cylindrical walls 12 and 13 of the hopper 11. Conductors 304 are received by the tube 302 and establish an electrical connection between the lamp 301 and a suitable source of electrical power, not shown.

The light produced by the lamp 301 is projected downwardly toward a rotatably mounted inspecting device 305, which is received within the hollow interior 51 of the inner cylindrical wall 37 of the housing 30. The inspecting device 305 includes a tubular shaft 306 that is journaled for rotation within the opening 51 by the bearings 53 and has its axis of rotation aligned with the vertex of the dispensing chute 15. To rotate the shaft 306, the drive pulley 54 is secured to the shaft 306 and has trained therearound the drive belt 55. The drive belt 55 is also trained around the drive pulley 56, which is secured to the shaft 57 of the continuously operated synchronous drive motor 58.

A light projecting and viewing housing 307 is included in the inspecting device 305 and is mounted on an outwardly projecting flange 308 of the tubular shaft 306 for rotation therewith. Mounted within the upper portion of the housing 307 is an optical system 309 that intercepts the light produced by the 'lamp 301 and projects a beam of light to illuminate articles within the inspection zone A. For this purpose, the optical system 309 comprises a horizontally disposed condensing lens 311, which is received by an opening 312 in the uppermost section of the housing 307. Positioned below the condensing lens 311 is a mirror 314 that is arranged to intercept the light passing through the condensing lens 311 and to refleet the light toward a converging lens 315, which is received by an opening 316 in the wall of the housing 307. The converging lens 315 is arranged to project a beam of light to illuminate articles within a restricted segment of the inspection zone A.

At the lower portion of the housing 307 is mounted an optical system 318 that receives light reflected from individual articles Within the same restricted segment of inspection zone A and transmits the reflected light so that the photOrn- ultipiier tubes 201 and 202 can detect the light reflecting properties of individually inspected articles. The optical systems 309 and 318 are separated in the housing 307 by an opaque partition 319. The optical system 318 comprises an objective lens 321, which is received by an opening 322 in the wall of the housing 307 and is disposed below the converging lens 315. Light reflected from articles within the inspection zone A and illuminated by light directed thereto by the optical system 309 is received by the objective lens 321. Centrally locarted within the lower portion of the housing 307 is a mirror 323 that is arranged to intercept the light passing through the lens 321 and to reflect the intercepted light downwardly through a converging lens 324, which is mounted within the tubular shaft 306. Disposed below the converging lens 324 and fixed to the inner wall of the tubular shaft 306 so as to rotate therewith is an opaque disc 325 that has an aperture, preferably a narrow slit 326, located at the center thereof. The slit 326 is in vertical alignment with the principal axis of the converging lens 324 and is of suitable size to permit only the light reflected from a small part of the illuminated segment of the inspection zone A to pass therethrough, thereby enabling the apparatus to inspect one article at a time.

Thus, the continuously rotating inspecting device 305 is centrally disposed with respect to the annular inspection zone A. The light projecting and viewing housing 307 rotates with the inspecting device 305. In the rotary movement of the housing 307, the optical system 309 intercepts the light produced by the lamp 301 and projects a beam of -light to successive adjoining portions of the inspection zone A. Further, the optical system 318 in its rotary movement with the housing 307 receives light reflected from successive adjoining portions of the inspection zone A and transmits in succession light reflected from individual articles falling in different paths within the inspection zone A. The aperture 326- of the opaque plate 325, which is a part of the inspecting device 305, limits the light reflected from the inspection zone A to enable inspection of one article at a time. the inspecting device 305 is arranged to illuminate the articles in the inspection zone A and to transmit in succession light reflected from each article individually that passes through the inspection zone A to enable the photomultiplier tubes 201 and 202 to detect the light reflecting properties of individually inspected articles.

As previously described in connection with the article sorting apparatus 200' (FIGS. -7, inclusive), the brush 83 thereof is mounted on the housing 59 for rotation therewith and the annular spark commutator 110 thereof is mounted on the base 18 of the stationary dispensing chute 15. In order that the rotatable brush 83 of the article sorting apparatus 300 (FIG. 8) be located so as not to block out any light projected from the lamp 301 toward the condensing lens 311, the brush 83 (FIG. 8) is carried by the lower portion of the tubular shaft 306. For this purpose, the brush 83 (FIG. 8) includes an annular base 340 of suitable conducting material, which has the inner cylindrical wall thereof fixed to the outer cylindrical wall of an insulated ring 341. The opening of the ring 341 receives the shaft 306 and the inner cylindrical wall of the ring 341 is secured in fixed relation with the shaft 306 for rotation therewith. The discharge end 84 (FIG. 8) of the brush 83 projects in the same general direction as the objective lens 321 and is spaced a suitable distance from the inner cylindrical wall 111 of the annular spark commutator 110 for establishing a spark discharge. The spark commutator 110 (FIG. 8) is supported by the base member 36 of the stationary housing 30 through the insulated bracket 113, which is secured to the lower surface of the base member 36. An

Accordingly,

electrical charge is transferred to the brush 83 from the pulse generator 270 (FIG. 7) through a rigid conductor 342 (FIG. 8) that is spaced a suitable distance from the base 340 of the brush 83 to establish a spark discharge and a lead 344 (FIG. 8) that connects the conductor 342 to the secondary winding 277 (FIG. 7) of the phase inverting pulse transformer 276, which has its primary winding 275 in the output circuit of the pulse generator 270. The conductor 342 (FIG. 8) is supported by an insulated post 343 that is mounted on the stationary housing 203.

Hence, the rotation of the brush 83 (FIG. 8) is synchronized with the rotation of the inspecting device 305 and the discharge end 84 of the brush 8-3 is indexed for movement with the objective lens 321 of the inspecting device 305. When a pulse is emitted from the pulse generator 270 (FIG. 7), a positive pulse is produced in the secondary winding 277 of the phase inverting pulse transformer 276. The positive pulse is conducted over the lead 344 (FIG. 8) and is transferred to the brush 83 in the form of a spark discharge through the conductor 342. The charge on the brush 83 in turn is transferred in the form of a spark discharge to the commutator segment 114 having the central portion thereof aligned with the discharge end 84 of the brush 83.

In the operation of the article sorting apparatus 300 (FIG. 8), precooked grains of rice are deposited into the hopper 11 and drop onto the dispensing chute 15, which distributes the grains of rice into a plurality of feed channels 17. Grains of rice advance in each feed channel in a single uniform layer and are spaced successively at predetermined intervals. As the grains of rice advancing in each feed channel reach the peripheral edge 19 of the dispensing chute 15, they fall freely and successively through the access opening 33 into the housing 30. The rice grains are discharged continuously from the feed channels 17.

The grains of rice that enter the housing 30 pass through the annular inspection zone A. The continuously rotating inspecting device 305 intercepts light produced by the lamp 301 and projects a beam of light to successive adjoining portions of the inspection zone A to illuminate the rice grains therein. In addition, the inspecting device 305 receives light reflected from successive adjoining portions of the inspection zone A and transmits in succession light reflected from individual rice grains falling in successive paths within the inspection zone A. The aperture 326 of the opaque plate 325, which is a part of the inspecting device 305, limits the light reflected from the inspection zone A to enable inspection of one rice grain at a time. A portion of the light passing thorugh the aperture 326 is reflected to the photomultiplier tube 201 by the half-silvered mirror 205.

The remaining portion of the light admitted through the aperture 326 passes through the half-silvered mirror 205 and is intercepted by the mirror 206, which transmits the intercepted light to the photomultiplier tube 202. The filter 207 limits the light admitted to the photomultiplier tube 201 to the wave lengths of light in the range from 400 to 500 millimicrons, while the filter 208 passes light for detection by the photomultiplier tube 202 of wave lengths in the range from 650 to 750 millimicrons.

The operation of the photomultiplier tubes 201 and 202 in conjunction with the comparator tube 229, the multivibrator 250 and the pulse generator 270 (all of which are shown in FIG. 7) has been described in detail relative to the article sorting apparatus 200. Therefore, the operation thereof will not be repeated. It is sufficient for the present disclosure to state that when a good rice grain is detected by the photomultiplier tubes. 201 and 202, the pulse generator 270 (FIG. 7) does not emit a pulse. Consequently, good rice grains are not deflected and continue in their path of travel in the inspection zone A to fall between the baffles and 131 in a manner heretofore described in connection with the article sorting apparatus 200. However, when the photomultiplier tubes 201 and 202 detect a bad rice grain, the pulse generator 270 emits a pulse. The pulse produced by the generator 270 charges the brush 83 through the phase inverting pulse transformer 276 (FIG. 7), lead 344 (FIG. 8), and conductor 342. The charge on the brush 83 is transferred to the commutator segment 114 associated with the feed channel from which the bad rice grain fell. As heretofore described relative to the article sorting apparatus 200, the trigger tube 115 (FIG. 7) associated with the changed commutator segment 114 is rendered conductive. As a result, the solenoid 116 (FIG. 7) associated with the conducting trigger tube 115 is energized for opening the valve 118 (FIG. 8) that is mechanically linked thereto. The opening of the valve 118 permits compressed air to flow into the air nozzle 121 (FIG. 8) associated with the feed channel from which the bad grain was dropped. Thus, the compressed air flowing through the ejector nozzle 121 segregates the bad rice grain from the good grains by causing it to fall between the baflles 131 and 132, while the good grains are permitted to fall into the space between the baflles 130 and 131.

It will be understood that modifications and variations of the embodiments of the invention disclosed herein may be resorted to without departing from the spirit of the invention and the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. An apparatus for sorting articles comprising means for etfecting the continuous advancement of the articles in a plurality of paths, means for illuminating said articles, single scanning means for successively scanning individual paths, said scanning means comprising means for receiving light reflected from articles in said paths as the paths are individually and successively scanned, said light receiving means including photoelectric means sensitive to variations in the light reflected from the articles, and means activated by signals from said photoelectric means for deflecting articles from said paths having certain lightreflecting characteristics.

2. An apparatus for sorting articles comprising a gravity chute for distributing the articles into a plurality of paths and effecting the continuous advancement of the articles as they are advanced in said paths, single scanning means for successively scanning said paths, said scanning means comprising means for receiving light reflected from each article as it moves in its path, said light receiving means being sensitive to variations in the light received thereby, and means at each path for actuation by said light receiving means for ejecting an article in response to variation from normal in the reflected light received by the light receiving means.

3. An apparatus for sorting articles comprising a frusto conical gravity chute means for distributing the articles into a plurality of paths and effecting the continuous advancement of the articles along said paths, means for illuminating the articles as they are advanced in said paths, single scanning means for successively scanning said paths, said scanning means comprising means for receiving light reflected from each article as it moves in its path, said light receiving means being sensitive to variations in the light received thereby, and means at each path for actuation by said light receiving means for ejecting an article in response to variation from normal in the reflected light received by the light receiving means.

4. An apparatus for sorting articles comprising means for distributing the articles into a plurality of paths Within an annular inspection zone, means for illuminating the articles in said inspection zone, a rotatably mounted device centrally disposed relative to said inspection zone for receiving light reflected from an article in each of said paths in succession, means for rotating said device and means responsive to variation in the reflected light received by said device for sorting the articles in accordance with their light reflecting properties.

5. An apparatus for sorting articles comprising a generally conical dispensing chute having a plurality of feed channels formed on the slanting surface thereof, said channels being arranged to discharge articles continuously into a plurality of paths within an inspection zone, means for illuminating the articles in said inspection zone, a device rotatable about an axis disposed in alignment with the central aris of said dispensing chute for succesively traversing said paths to receive light reflected from each article in said paths, means responsive to changes in the reflected light received by said device for sorting the articles in accordance with their light reflecting properties, and means for rotating said device at a speed commensurate with the movement of articles into said inspection zone, whereby each continuously moving article in each path is processed.

6. An apparatus for sorting articles according to color comprising means for distributing the articles into a plurality of paths within an annular inspection zone, means for illuminating the articles in said inspection zone, article ejecting means for each of said paths disposed adjacent its associated path, a stationary commutator segment for each of said article ejecting means, said commutator segments being arranged to form an annular commutator, a rotatably mounted device centrally disposed relative to said inspection zone for successively receiving light reflected from each article in said paths, a brush mounted for rotary movement about an axis centrally disposed relative to said commutator segments, means for rotating said brush in synchronism with the rotary movement of said device, means responsive to the reflected light received by said device for charging said brush when light reflected from an article having a predetermined surface luminosity is received by the device, said brush having a discharge portion arranged to transfer the charge thereon to the commutator segment aligned therewith, and means responsive to the charge on said aligned commutator segment for activating the ejector means associated with said aligned commutator segment for deflecting the article having the predetermined surface luminosity from its said path of travel in said inspection zone.

7. An apparatus for sorting articles according to color comprising means for distributing the articles into a plurality of paths within an annular inspection zone, means for illuminating the articles in said inspection zone, an air nozzle for each of said paths of articles disposed adjacent its associated path, a stationary commutator segment for each of said air nozzles, said commutator segments being arranged to form an annular commutator, a rotatably mounted device centrally disposed relative to said inspection zone for successively receiving light reflected from each article in said paths, a brush mounted for rotary movement about an axis centrally disposed relative to said commutator segments, means for rotating said brush in sy-nchronism with the rotary movement of said device, means responsive to changes in the color of reflected light received by said device for charging said brush when light received from an article of a predetermined color is received by said device, said brush having a discharge portion arranged to transfer the charge thereon to the commutator segment aligned therewith, and means responsive to the charge on said aligned commutator segment for delivering air through the air nozzle associated with said aligned commutator segment for deflecting the article of the predetermined color from its said path of travel in said inspection zone.

8. In an apparatus for sorting articles, means for continuously feeding articles along a plurality of paths that cross an annular inspection zone, a viewing housing, means for rotating said viewing housing about an axis centrally disposed relative to said annular inspection zone and at a speed commensurate with the movement of articles through said inspection zone, and an objective lens mounted in said housing and arranged to intercept light from articles in paths crossing successive portions of said inspection zone.

9. An apparatus for sorting articles according to color comprising means for distributing the articles into a plurality of paths within an annular inspection zone, means for illuminating the articles in said inspection zone, a rotatably mounted device centrally disposed relative to said test zone for successively receiving light reflected from articles in different ones of said paths, a first circuit responsive to the reflected light received by said device for producing a signal representative of the light reflecting properties of an article in one portion of the light spectrum, a second circuit responsive to the reflected light received by said device for producing a signal representative of the light reflecting properties of the article in another portion of the light spectrum, circuit means responsive to the signals produced by said first and second circuits for producing a comparison voltage, and means responsive to the comparison voltage for segregating the article in accordance with its light reflecting properties.

10. An apparatus for sorting articles according to color comprising means for distributing the articles into a plurality of paths within an annular inspection zone, means for illuminating the articles in said inspection zone, article ejecting means for each of said paths disposed adjacent its associated path, a stationary commutator segment for each of said article ejecting means, said commutator segments being arranged to form an annular commutator, a rotatably mounted device centrally disposed relative to said inspection zone for receiving in succession light reflected from articles in diflerent ones of said paths, a brush mounted for rotary movement about an axis centrally disposed relative to said commutator segments, means for rotating said brush in synchronism with the rotary movement of said device, means operative in synchronism with the rotation of said brush for producing a synchronizing voltage when said brush is aligned With each of said commutator segments, circuit means responsive to said synchronizing voltage and the reflected light viewed by said device for charging said brush when an article of a predetermined color is detected, said brush having a discharge portion arranged to transfer the charge thereon to the commutator segment having the central portion thereof aligned with said brush, and means responsive to the charge on the charged commutator segment for activating the ejector means associated with the charged commutator segment for deflecting the article having the predetermined color from its path of travel in said inspection zone.

11. An apparatus for sorting articles according to color comprising means for discharging articles into an inspection zone, means for illuminating the articles in the inspection zone, a first light responsive means for producing a signal representative of the light reflecting properties of an article in one portion of the light spectrum, a second light responsive means for producing a signal representative of the light reflecting properties of the article in another portion of the spectrum, means for receiving light reflected from an article in said inspection zone and for transmitting the light received thereby to both of said light responsive means, an electron discharge device having the potential on one element thereof controlled by the signal produced by said first light responsive means and having the potential on another element thereof controlled by the signal produced by said second light responsive means, and means responsive to the output potential of said electron discharge device for segregating the article in accordance with its light reflecting properties.

12. An apparatus for sorting articles according to color comprising means for distributing the articles into a plurality of paths Within an inspection zone, means for illuminating the articles in said inspection zone, article ejecting means for each of said paths disposed adjacent its associated path, a stationary commutator segment for each of said article ejecting means, said segments being disposed in annular array, a rotatably mounted device for successively receiving light reflected from each article in said paths, a brush mounted for rotary movement about an axis centrally disposed relative to said array of commutator segments, means for rotating said brush in synchronism With the rotary movement of said device, a first circuit responsive to the reflected light received by said device for producing a signal representative of the light reflecting properties of an article in one portion of the light spectrum, a second circuit responsive to the refle'cted light received by said device for producing a signal representative of the light reflecting properties of the articles in another portion of the light spectrum, circuit means responsive to the signals produced by said first and second circuits for producing a comparison voltage, means operative in synchronism with the rotation of said brush for producing a synchronizing voltage when said brush is adjacent each of said commutator segments, a pulsing circuit responsive to said comparison voltage and said synchronizing voltage for charging said. brush when said device receives light reflected from an article of a predetermined color, said brush having a discharge portion arranged to transfer the charge thereon to the commutator segment aligned with said brush, and means responsive to the charge on said charged commutator segment for activating the ejector means associated with said charged commutator segment for deflecting the article having the predetermined color from its path of travel in said inspection zone.

13. An apparatus for sorting articles according to color comprising means for discharging articles into an inspection zone, means for illuminating the articles in said inspection zone, a first light responsive circuit arranged to receive light reflected from one of the articles for producing a signal representative of the light reflecting properties of the article in one portion of the light spectrum, a second light responsive circuit arranged to receive light reflected from said one article for producing a signal representative of the light reflecting properties of the article in another portion of the spectrum, means responsive to the signals produced by said first and second light responsive circuits for producing a comparison voltage, means for producing a synchronizing voltage, and means responsive to said comparison voltage and said synchronizing voltage for segregating the article in, accordance with its light reflecting properties.

14. An apparatus for sorting articles comprising means for distributing articles into a plurality of paths within an inspection zone, means for illuminating the articles in said inspection zone, article ejecting means for each of said paths disposed adjacent its associated path, a gasfil'led trigger tube for each of said ejecting means controlling the operation of its associated ejecting means, means for cyclically and sequentially impressing a positive and negative potential on the plates of said trigger tubes, a commutator segment connected to each of said trigger tubes, said segments being disposed in annular array, a brush rotatably mounted for movement about an axis centrally disposed relative to said array of commutator segments, means for rotating said brush, means responsive to the light reflecting properties of said articles for charging said brush when an article having a predetermined surface luminosity is detected, said brush having a discharge portion arranged to transfer the charge thereon to the commutator segment aligned therewith, whereby the trigger tube associated with said aligned commutator segment conducts When a positive potential is impressed on its plate for activating its associated ejector means to deflect the article having said surface luminosity from its path of travel in said inspection zone and said conducting trigger tube extinguishes when a negative potential is impressed on its plate.

15. A method of sorting articles comprising the steps of feeding the articles continuously from a plurality of feed channels into paths that cross an annular inspection zone, illuminating the articles in the inspection zone, suc- 19 cessively inspecting the articles in individual paths as the articles cross said annular inspection zone by rotating a scanner that receives the light reflected from each article as it crosses said inspection zone, and segregating the inspected articles in accordance with their light reflecting properties.

16. In an apparatus for sorting articles according to color, a first light responsive device for producing a signal representative of the light reflecting properties of an article in one portion of the light spectrum, a second light responsive device for producing a signal representative of the light reflecting properties of the article in another portion of the spectrum, an optical system arranged to receive light reflected from the article and to transmit the light received thereby to both of said light responsive devices, a comparator circuit for producing a comparison voltage in response to the signals produced by said first and second devices, means for producing a synchronizing voltage, a multivibrator having one tube thereof responsive to the comparison voltage and having another tube thereof responsive to the synchronizing voltage for emitting a trigger pulse, and means responsive to the trigger pulse for segregating the article in accordance with its light reflecting properties.

17. An apparatus for sorting articles comprising a first light responsive device for producing a signal representative of the light reflecting properties of an article in one portion of the light spectrum, a second light responsive device for producing a signal representative of the light reflecting properties of the article in another portion of the spectrum, an optical system arranged to receive light reflected from the article and to transmit the light received thereby to both of said light responsive devices, a comparator circuit responsive to the signals produced by said first and second devices for producing a comparison signal, a multivibrator responsive to the comparison signal for emitting a trigger pulse, and means responsive to the trigger pulse for segregating the article in accordance with its light reflecting properties.

18. An apparatus for sorting articles comprising means for effecting advancement of the articles in a plurality of paths that cross an annular inspection zone, a rotatably mounted device centrally disposed relative to said inspection zone for projecting a beam of light toward articles in. successive individual paths and means for receiving light reflected from articles as they are successively illuminated by the beam of light and means responsive to variations in the reflected light received by said device for sorting the articles in accordance with their respective surface luminosities.

19. An apparatus for sorting articles according to color comprising means for distributing the articles into a plurality of paths that cross an annular inspection zone, means for illuminating the articles in said inspection zone, article diverting means for each of said paths disposed adjacent its associated path, electrically energized actuating means for each of said article diverting means, a rotatably mounted device centrally disposed relative to said inspection zone for receiving light reflected from each article in successive individual paths, a control circuit for said actuating means including current transfer means carried by said rotatable device and arranged to be energized in response to the reflected light received by said device when light reflected from an article having a predetermined surface luminosity is received by the device, said current transfer means being arranged to energize the actuating means aligned therewith, and means responsive to the energization of each actuating means for activating the diverting means associated with said transfer means for deflecting the article having the predetermined surface luminosity from its said path of travel in said inspection zone.

20. An apparatus for sorting articles according to color comprising means for distributing the articles into a plurality of paths within an annular inspection zone, means 'for illuminating the articles in said inspection zone, diverting means for each of said paths disposed adjacent its associated path, a stationary electrically energized actuator for each of said article ejecting means, a rotatably mounted device centrally disposed relative to said inspection zone for receiving in succession light reflected from articles in different ones of said paths, current transfer means carried by said rotatable device, means operative in synchronism with the rotation of said device for producing a synchronizing voltage when said current transfer means is aligned with each of said actuators, circuit means responsive to said synchronizing voltage and the reflected light viewed by said device for energizing said transfer means when an article of a predetermined color is detected, said transfer means having a discharge portion arranged to energize the actuator aligned therewith, and means responsive to the energization of said actuator for activating the associated diverting means for deflecting the article having the predetermined color from its path of travel in said inspection zone.

21. An apparatus for sorting articles according to color comprising means for distributing the articles into a plurality of paths within an annular inspection zone, means for illuminating the articles in said inspection zone, a rotatable device for successively receiving light reflected from articles in different ones of said paths, a first circuit responsive to the reflected light received by said device for producing a signal representative of the light reflecting properties of an article in one portion of the light spectrum, a second circuit responsive to the reflected light received by said device for producing a signal representative of the light reflecting properties of the article in another portion of the light spectrum, circuit means responsive to the signals produced by said first and second circuits for producing a comparison voltage, and means responsive to the comparison voltage for segregating the article in accordance with its light reflecting properties.

22. An apparatus for sorting articles according to color comprising means for distributing the articles into a plurality of paths within an annular inspection zone, means for successively scanning said paths individually to receive light reflected from articles in said paths, said light receiving means being sensitive to variations in the intensity of light received thereby and including a lens assembly mounted for rotation centrally of said annular inspection zone, and means activated by said light receiving means for deflecting from said paths articles having certain lightreflecting characteristics.

23. An apparatus for sorting articles comprising means for distributing articles into a plurality of paths that cross an annular inspection zone, a rotatably mounted device centrally disposed relative to said inspection zone for receiving light successively from each article in said paths, said device being adapted to detect differences in the light reflecting properties of different articles, said device including a lens assembly for directing a beam to said zone a lamp for directing light onto said lens assembly, photo electric means and means in said device for directing light reflected from articles crossing said inspection zone to said photoelectric means, said photoelectric means being responsive to changes in the light reflecting properties of said articles detected by said device for sorting said articles in accordance with their respective surface luminosities.

24. An apparatus for sorting articles comprising means for distributing the articles into a plurality of paths that cross an annular inspection zone, means for illuminating the articles in said inspection zone, a rotatably mounted device centrally disposed relative to said inspection zone for receiving light reflected from an article in each of said paths in succession, means for imparting one revolution to said device during the time required for an article to cross said inspection zone, whereby said device receives light from each article, and means responsive to variation in 21 the reflected light received by said device for sorting the 2,190,5 63 articles in accordance with their light reflecting properties. 2,244,826 2,773,596

References Cited in the file of this patent UNITED STATES PATENTS 5 642,283 1,921,862 Bickley Aug. 8, 1933 784,569

22 Horsfield Feb. 13, 1940 Cox June 10, 1941 Bartlett Dec. 11, 1956 FOREIGN PATENTS Great Britain Aug. 30, 1950 France Apr. 29, 1935

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