US3415496A - Sorting machine - Google Patents

Description

De. 10, 1968 J- s. EVANS, JR 3,415,496

SORTING MACHINE Filed July 15, 1967 2 Sheets-Sheet 1 A, v fl \y (\K I? I4 2 ll I 22 i 42 :E I |3 :3 IE I E: 3

INVENTOR.

JOHN s. EVANS, JR. IE I I3 1 ATTORNEY Dec. 10, 1968 .J- s. EVANS, JR 3,415,496

SORTING MACHINE Filed July 13, 1967 2 Sheets-$heet 2 IE I I3 l3 T I E EI I B INVENTOR.

JOHN S. EVA1NS,JR.

BY fins/4a.

ATTORNEY United States Patent 3,415,496 SORTING MACHINE John S. Evans, Jr., Houston, Tex., assignor to Mandrel Industries, Inc., Houston, Tex., a corporation of Michigan Filed July 13, 1967, Ser. No. 653,062

Claims. (Cl. 259-85) ABSTRACT OF THE DISCLOSURE Objects such as rice grains to be sorted are fed into a rapidly rotating bowl, and centrifugal forces distribute the grains at the periphery of the bowl to facilitate their being picked up by a rotating suction wheel for examination, classification and sorting. As each grain is picked up, the remaining grains shift their positions in the bowl to fill up the vacancy. However, static friction between the grains and the bowl opposes this shifting action. Also, the grains tend to build up in clusters around the sides of the bowl. Therefore, a paddle member is provided extending radially from the axis of the bowl and rotating at a different speed. The paddle member sweeps the inner bowl surface near its periphery, and periodically disturbs the rice grains to initiate the desired shifting motion and provide a more uniform distribution.

Background of the invention Field-Classifying, Separating and Assorting Solids, particularly Automatic Assortin g, With Feeding (:209-73).

Prior Art.-U.S. Patent 2,325,665 shows a sorting machinewith a centrifugally operating bowl feed device, in which static friction is broken by alternately accelerating and decelerating the rotating bowl with an eccentric drive pulley. However, this solution is satisfactory only with relatively low-speed sorting machines and is not suitable for the high-speed machines, toward which the art is progressing.

Summary of the invention The object of the invention is to provide a bowl-type feed device for a high-speed sorting machine in which static frictionbetween the bowl and the objects to be sorted is at least periodically broken without altering the rotational speed of the bowl. Accordingly, a paddle member is mounted for rotation within the bowl and for sweeping the inner surface thereof so as to periodically disturb the array of objects, facilitating their shifting motion, and providing a more uniform distribution of the objects.

The drawing FIGURE 1 is a cross-sectional elevation view of a sorting machine feed apparatus according to the invention;

FIGURE 2 is an enlarged view taken on the plane of lines 22 of FIGURE 1;

FIGURE 3 is a cross-sectional view taken on the plane of lines 33 of FIGURE 2;

FIGURE 4 is a cross-sectional elevation view of an alternative embodiment of the apparatus of the invention;

FIGURE 5 is an enlarged view taken on the plane of lines 55 of FIGURE 4;

FIGURE 6 is a view taken on the plane of lines 6-6 of FIGURE 5; and

FIGURE 7 is a view taken on the plane of lines 7-7 of FIGURE 5.

Description 0 the preferred embodiments Referring now to the drawing, particularly to FIG. 1, there is shown a rotating bowl assembly 11, such as may be substituted for the bowl 49 of FIG. "2 of U.S. Patent 2,325,665 for centrifugally distributing small solid objects such as rice grains to facilitate pickup of the grains "ice by a rotating suction wheel such as the member 4 of the cross-referenced patent. While the machine of the crossreferenced patent is a comparatively low-speed machine, the bowl assembly 11 of the present invention could nevertheless be used therein if the machine were operated at a higher speed. To accommodate the objects without flinging them out at such higher speed, the bowl assembly 11 of the present invention is formed with considerably steeper sides and an inwardly directed flange 12 at the periphery thereof. For convenience of manufacture, the bowl assembly 11 is divided into two parts: an outer mounting bowl support 13 formed with a hub portion 14; and a removable inner bowl 16, which bears the flange 12 and is secured on the hub portion 14 of the outer bowl support 13 by means of a clamping spider 17 and bolts 18. Also mounted on the spider 17 is a bowl plate 19, which has a peripheral flange 21 in pressurized engagement with the bottom of the bowl 16 and helps to guide the product rapidly outward. Into the hub portion 14 is press-fitted ahollow shaft 22 that is journaled for rotation in a bearing assembly 23, the bearing assembly being solidly mounted on the machine with which the bowl is to be used. The shaft 22 is driven by means of a belt pulley 24 and drive means of any suitable type known in the art and not here shown.

It will be understood that small solid objects such as rice grains that are placed in the rotating bowl 16 are distributed by centrifugal action around the upstanding sides 26 of the bowl 16, so that the grains may be more easily picked up by a rotating suction wheel for examination, classification and sorting. However, the centrifugal forces applied to the grains also result in an increase of the static friction between the grains and the bowl, and it may happen that when a grain is picked up, the adjacent grains will not immediately rearrange themselves to fill up the vacancy. Also, there is a tendency for the rice grains to build up in uneven masses against the side of the bowl, further impeding the pick-up process and sometimes destroying the dynamic balance of the bowl. To break this static friction, a rotating paddle 27 is provided to sweep the inside of the bowl 16 and periodically disturb the arrangement of the grains and break up undesired masses of accumulated grains.

To provide for rotation of the paddle 27 at a different speed than that of the bowl 16, a paddle shaft 28 is fitted in bearings 29 and 30 so as to extend through and from the hollow shaft 22 of the bowl. At the upper end of the shaft 28 there is mounted a hub 31 that extends radially in axially spaced relation to the hub portion 14 of the bowl, and has openings 32 formed therein for feeding of the objects into the bowl. An arm 33 is mounted to extend radially from a hole 34 in the hub 31, and the paddle 27 is affixed at the end of the arm. To assist in feeding the objects through the opening 32 of the hub, a funnel member 36 is secured to the hub, encompassing the openings 32 and opening upwardly in the same direction as the bowl; and a hemispherical deflector 37 is mounted at the center of the hub 31 to assist in guiding the objects. A splash deflecting plate 38 is also secured to the hub 31 outside the zone of holes 32 and between the arm 33 and the plate 19. The plate 38 has a concave side facing the bottom of the bowl, but the periphery of the plate is spaced substantially from the bottom and sides of the bowl to permit a free radial flow of the objects to be sorted. The shaft 28 is driven by a separate belt pulley 39, and at a different speed than that of the bowl. One mode of operation that has been found satisfactory in practice, with rice, is to drive the bowl at about 200 revolutions per minute and the paddle about 10 r.p.m. faster, or slower, in the same rotational direction.

As shown in FIG. 1, the paddle 27 has a generally U- shaped form, the tip of one side 41 of which is coupled to the arm 33 and the other side 42 of which is spaced slightly (e.g., to A; inch) from the inner surface of the bowl 16. The spacing is adjusted by means of a set screw 44 threaded through the hub 31 and engaging the paddle arm 33. Both sides of the paddle extend toward the opening of the bowl from the bent portion 43 of the paddle. Furthermore, at least the side 42 of the paddle has a dimension (e.g., 10 mils) substantially smaller in a radial direction of the bowl than the average diameter of the objects (e.g., peas), so that upon engaging the objects, the side 42 of the paddle merely slips beneath or over them and temporarily dislodges them, but does not move them substantially from their previous circumferential positions with respect to the bowl.

For sorting some objects, such as coffee beans, the paddle 27 may have a uniform width (of e.g., about /1 inch) throughout both sides 41, 42 and the bent portion 43. However, for sorting rice grains, the configuration shown in FIGURES 2 and 3 has been found effective, in which a flap 46 is formed on the trailing edge of the side 42, upstream in the direction of motion 47 of the paddle relative to the bowl. The flap 46 is angled slightly toward the center of the bowl, and gives accumulated rice grains a slight lift radially away from the bowl sides in passing, to help break up accumulations or masses of grains.

Referring now to FIG. 4, a further preferred embodiment is shown in which most of the elements are generally similar to those of FIG. 1, and are designated with similar reference numerals: i.e., a hollow shaft 22a, a hub portion 14a, a clamp 17a, a changeable bowl 16a, a shaft 28a, a bearing 29a, a hub 31a, a deflector 37a, and a flange 12a for the bowl 16a. However, the hub 31a does not have any openings 32, funnel 36, or splash deflecting plate 38 mounted thereon. On the hub 31a are mounted two arms 33a at the ends of which are aflixed ploughshaped paddles 27a. The arms 33a are mounted by insertion into openings 51 and 52 that are formed in the hub and are secured by means of set screws 53 and 54 threaded into the hub. The openings 51 and 52 are set at slightly different angles to the axis of the paddle shaft 28a, these angles being measured in lanes containing the axis of the bowl and extending radially therefrom (i.e., the plane of the drawing sheet). Thus, as will be readily apparent, one of the paddles 27a is arranged to sweep the inside surface of the bowl 16a near the periphery thereof, while the other paddle 27a is arranged to sweep the bowl at a second level further from the periphery of the bowl. The blades of the paddles are set at an adjustable angle to the direction of motion 61, as shown in FIGURES -7, so as to deflect the objects encountered toward the periphery of the bowl.

Thus, there has been described a bowl-type feed device for a high-speed sorting machine in which static friction between the bowl and the objects to be sorted is at least periodically broken without altering the rotational speed of the bowl. Accordingly, a paddle member is mounted for rotation within the bowl and for sweeping the inner surface thereof so as to periodically disturb the array of objects, facilitating their shifting motion, and providing a more uniform distribution of the objects.

What is claimed is:

1. A rotating concave bowl type feed device for centrifugally distributing a plurality of objects at the periphery thereof, comprising:

a concave bowl mounted for rotation;

a hub mounted for rotation at the center of said bowl;

an arm extending radially from said hub;

a paddle extending from said arm and subtending a substantial radial segment of the inner bowl surface near said periphery thereof;

said paddle having a generally U-shaped form, the tip of one side of which is coupled to said arm and the other side of which is spaced slightly from said inner surface of said bowl, said other side being substantially thinner in a radial direction of said bowl than the average diameter of said objects, and both of said sides extending toward the opening of said bowl; and

means for rotating said bowl and said hub at differing angular velocities;

whereby said objects are periodically disturbed, so that static friction between said objects and said bowl is broken and said objects are uniformly distributed at the periphery of said bowl.

2. The combination as recited in claim 1, wherein said one side of said paddle has a flap extending therefrom upstream in the direction of motion of said paddle with respect to said bowl, said flap being angled toward the center of said bowl.

3. The combination as recited in claim 2, wherein:

said bowl includes a central hub portion mounted on a first hollow shaft; 7

said first-named hub is mounted on a second shaft extending through and from said hollow shaft of said bowl, so that said first-named hub lies on the side of said bowl hub portion toward the opening of said bowl; and

a pulley is mounted on each of said shafts remote from said bowl for separately driving said shafts.

4. The combination as recited in claim 3, wherein:

said first-named hub extends radially in axially spaced relation to said hub portion of said bowl, and has openings formed therein for feeding of said objects into said bowl; and

a funnel member is secured to said first-named hub encompassing said openings on the side thereof toward the opening of said bowl, for guiding said objects to said openings.

5. The combination as recited in claim 4, wherein:

a concave circular splash deflecting plate is secured to said first-named hub between said arm and the bottom of said bowl, with the concave side of said plate facing the bottom of said bowl.

References Cited UNITED STATES PATENTS 733,973 7/1903 Knowlton 259 2,325,665 8/1943 Cox 209-73 2,639,903 5/1953 Kacena 25985 ROBERT W. JENKINS, Primary Examiner.

US. Cl. X.R.

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