US3002617A

US3002617A - Grading machines

Info

Publication number: US3002617A
Application number: US658321A
Authority: US
Inventors: Fraenkel Herbert
Original assignee: R W GUNSON SEEDS Ltd
Current assignee: R W GUNSON (SEEDS) Ltd; R W GUNSON SEEDS Ltd
Priority date: 1956-05-11
Filing date: 1957-05-10
Publication date: 1961-10-03
Anticipated expiration: 1978-10-03

Description

H. FRAENKEL GRADING MACHINES Oct. 3, 1961 4 Sheets-Sheet 1 Filed May 10, 1957 Inventor:

Oct. 3, 1961 H. FRAENKEL GRADING MACHINES 4 Sheets-Sheet 2 Filed May 10, 1957 F/GS.

Invenlor: Hmw Fi By o o 73 1mg:

Oct. 3, 1961 H. FRAENKEL GRADING MACHINES 4 Sheets-Sheet 3 Filed May 10, 1957 b m m URN OWN Inventor;

Oct. 3, 1961 H. FRAENKEL GRADING MACHINES 4 Sheets-Sheet 4 Filed May 10. 1957 ll. R mm R mm wm rllllll vmik Inventor: HM F/uwni By; 0 Eddwfin W Attorneys United States Patent This invention relates to grading machines to grade or sort materials by reference to their dimensions. The invention is more especially concerned with the grading of articles which although of elongated form, have a somewhat small ratio of major/minor dimension: examples of such articles are pea-nuts and harricot beans in the class of natural products, and certain classes of confectionery or medicinal tablets in the class of manufactured products.

The grading of such articles has presented some dilficulty by reason of the small ratio and especially where it is important that the grading operation shall not damage the surface appearance of the article: for example in the case of pea-nuts, their marketable value depends considerably on the condition of the skin" and any damage to it reduces the market value: again it is essential that the nuts shall not be split in the grading process for this makes them virtually unsaleable.

The main object of this invention is to provide a grading machine which will enable articles of the class referred to to be graded at high speed with the minimum of risk of damaging or soiling them.

Broadly stated a grading machine according to this invention comprises a table which is vibrated in its longitudinal sense so as to advance with a substantially uniform velocity articles fed to it to a grading zone and the surface of the table is formed as by grooving it so that, by the vibrating action, the table arranges and holds the articles as they are advanced in an orderly array with the major dimension of the articles in the sense of advance whereby the articles pass to the grading zone with a smooth continuous progression with the same orientation. The grooves in the table extend in the lengthwise sense of the tale, i.e. in the sense of its vibration, and these grooves are of such form that the vibrating action causes the articles to settle in the grooves with th ir major dimension arranged in the sense of movement along the tables. The table is, in accordance with the invention, constituted by an entry portion formed with longitudinally extending preliminary orienting grooves and a main portion formed with orienting grooves, the entry portion having a small upward inclination relative to the main portion.

For a grading action in terms of the major dimension (which will be referred to hereinafter as the length) the grading zone is formed by the gap defined between the discharge end of the table and a catch plate at a somewhat lower level; thus as the now orientated articles are continuously advanced they will have a certain momentum which will tend to project them across the gap to the plate: as however the advancing action causes more and more of the leading part of the article to overhang the edge of the table, and less and less of its trailing part to be supported by the table, the factor of length comes into play determining whether the leading end will be caught by the plate before the article falls through the gap.

While in many cases it would be sufficient to have the discharge points constituted by unguarded gaps, it would in general be preferred to arrange at each gap 8. control device which is interposed adjacent the trajectory of the articles as they are projected across the gap from the table: this device is adjustable so that it can be set to exercise a fine control on the grading by intercepting those lacking the uniformity of their transverse dimen sion or shape: in the result, therefore, the articles which pass the control devices would be of the higher grade as to weight and uniformity.

An important factor in the satisfactory operation of the apparatus is constancy of the frequency and amplitude of vibration of the table and hence rate of advance of the articles: for this reason the vibrator mechanism is preferably of the electro-magnetic type arranged for electrical operation conveniently at the frequency which now applies in most public A.C. supply mains, e.g. 50 cycles per second. Such a frequency has been found suflicient to cause the articles to advance over the tables with a smooth gliding action.

Obviously a number of such tables set to produce an increasingly fine grading action could be arranged in series as regarded in the sense of advance of the articles.

It may be desirable to feed the articles to the table ,by a feed tray which is itself vibrated but by its own vibrating device so that the frequency and/or amplitude of vibration of the table and of the separately vibrated feed tray can be independently selected to suit the particular functions of each.

The invention is illustrated in the accompanying drawings, in which FIGURES l-5 show a machine intended to operate as a length grading machine.

In the drawings, FIGURE 1 is a side elevation of a complete length machine, FIGURE 2 is a front elevation of the machine, FIGURE 3 is a detail plan view, and FIGURES 4 and 5 are sections on the lines IV-IV and V-V of FIGURE 3.

Referring to the length grading machine shown in FIGURES l-5, the machine comprises a frame 1 supported by the upper ends of a pair of

blade springs

2, 3 which incline upwardly and rearwardly from their lower ends where they are anchored to a sub-base frame 4. These blade springs support the frame 1 either horizontally or with a small inclination as is shown in the sense in which the articles to be graded are required to advance. These springs, while being preferable could be replaced by equivalent pivoted arms.

The sub-base 4 carries two

electromagnets

5, 6, one for each spring (or arm) and the springs Z, 3 have armatures 7, 8 for cooperation with the electromagnets, the windings of which are arranged to be energised by opposite phases across an A.C. supply main. The support 4 is itself supported from a main base 9 through springs housed in housings 10, the springs serving to absorb vibrations transmitted to them by supporting posts 11 connected to the sub-base 4, and permitting the sub-base 4 to vibrate relatively to the main base 9.

Thus when the windings are energized the frame 1 is caused to vibrate at the frequency of the main supply.

Now in the machine shown in FIGURES l-S, this vibration of the frame 1 is employed to effect a lengthgrading action on articles such as pea-nuts which pass from a feed hopper 12 having discharge mouths to a tray 12a with a feed opening at its front end over a receiving platform 13 formed at one end of the frame 1, the rate of feed being controlled by adjustable control gates 14.

This platform 13 is formed with increasing longitudinal grooves 15 which, as a result of the vibration of the frame 1, cause the articles to have a rough preliminary lengthwise aligning.

The edge of the platform aligning table formed in two

parts

16, 17 which are supported by ribs 18 rising from the frame 1 which is of U cross-section. Both

parts

16, 17 are pressed out to provide longitudinal orienting grooves 19, forming a continuation of one another, the grooves 19 in the

table portions

16 and 17 being respectively aligned. The grooves 19 have as shown downwardly and inwardly sloping side 13 terminates over a main;

3 vans with radiused upper and lower corners: in addition the width of the grooves at their base is somewhat smaller than the smallest lengths of the articles to be graded.

in the result, the vibration of the frame 1 causes the articles to advance progressively along theplatform 13 and then to move to the entry portion 16 of the table or plate along which the advance is continued to the main portion 17. During this advance the articles will settle in the grooves and advance in an orderly fashion in lengthwise alignmentin which they are held by the grooves. The sorting of the articles is facilitated by causing them to be slowed down slightly and given a preliminary orientation and distribution during the initial action of the entry portion 16 and for this purpose this part has a slightly negative slope as compared with the part 17, that is, the entry portion 16 has a small upward inclination as compared to the main portion 17 in the direction of advance of the articles to be graded. I i

In order now to effect a length grading action on the orderly advancing articles a second plate 22 is provided at a slightly lower level than the part 17 at its forward end and this plate 22 is arranged to leave a gap 23 between itself and the part 17. As the articles pass over the edge of the part 17 they will (if sufficiently lon be supported at their trailing end by the plate 17 sufiiciently to be caught by the plate 22, which thus serves as a catch mem: her and which will support them over the gap 23 and will continue to advance them: if, however, they are shorter than the prescribed length, they will not advance to be supported by the plate 22 but will fall or topple through the gap 23. The desired length grading operation is thus elfected, the articles falling through the gap 23 having a length shorter than those carried over the gap. I

In order to improve the grading selection, a control bar component 24 can be disposed in the path which the articles traverse as they move across the gap; this bar is adjustable to vary the position of its upper edge with respect to the trajectory of the articles. In the case shown, this is efiected by supporting the ends of the bar 24 by brackets 25 having vertical adjusting slots receiving clamp ing bolts 26 screwing into a bracket 27 having longitudinal adjusting slots receiving bolts 28 screwing into lugs on the frame 1.

This control bar 24 is formed as shown with a waved upper edge to prevent articles from settling or lodging on it and so choking the flow of articles.

The articles passing through the gap 23 and those passing on to the plate 22 can be separately collected at this first stage of grading. It is however preferred to arrange the unit shown to provide two stages for which purpose the plate 22 is also grooved and terminates over a gap having a control bar as has already been described, the corresponding parts being indicated by the same reference numerals with the suflix a.

In such a case, the bar 24a and the gap could be set to produce a further length grading of the articles which pass along the plate 22: however as shown the second stage can be employed to achieve a second similar action on the articles which have passed the gap 23 of the first stage. In such a case the articles which fall through the gap 23 are collected with those falling through the gap 23a and those which pass over both gaps are collected separately: for this purpose, the plate 22 is spaced above the base of the frame 1 so as to provide between the ribs 18 a number of passages 30 which pass forwardly below the gap 23a and extend over a discharge chute 31. The articles which pass the second gap 23a pass to a second chute 32.

To provide an alternative grading, the base of the 4' frame 1 can have openings 30a to enable articles passing through the gap in the first stage to be separately col lected in a chute 31a, the openings being masked by plates 31b for the first method of collection.

Provision can be made to direct an air blast across the path of movement of thear'ticles so as to remove light matter such as chad from the stream of articles: this could be arranged at the feed zone and/ or to the articles as they move" along the grading section, for which pur-- pose air nozzles 52 can be provided.

I claim:

1. Agrading machine comprising a table mounted for vibration in the direction of its length and having a main portion formed Wit h a plurality of longitudinally extending'article orienting grooves, and an entry portion formed with a plurality of longitudinally extending preliminary article orienting grooves aligned respectively with the orienting grooves in said main portion, said entry portion having a small upward inclination relative to said main portion in the direction of longitudinal advance of the articles to be graded, means for feeding elongated articles to be graded onto said entry portion, means to vibrate the table a longitudinal sense to advance articles fed to the entryportion progressively through said preliminary orientin'gg'rqoves andinto and through the aligned grooves of said main portion, and a catch member disposed adjac'e'nt to and spaced from the main portion and defining therewith a'grading gap to which the articles move in their advance.

2. A grading machine comprising a table mounted for vibration inthe' direction of its length and having a main portion formed with a pluralityof longitudinally extending article o'rienting grooves, and an entry portion formed with a plurality of iongitudinally extending preliminary article orienting grooves aligned respectively with the orienting grooves, in said main portion, said entry portion having a'. small upwardinclination relative to said main portion inthe' direction of longitudinal advance of the articles to be graded, means for feeding elongated articles to be graded onto s'a'identry portion, means to vibrate the tablejin a longitudinal sense to advance articles fed to the entry portion progressively through said preliminary orienting grooves and into and through the aligned grooves of said main portion, a catch member disposed adjacent to and spaced from the main portion and defining therewith a grading gap to which the articles move in their advance, a vertically adjustable control component in said gap arranged adjacent the path of movement of the articles at the gap, and means for securing the control component in adjusted position.

utterances Cited in the file of this patent UNITED STATES PATENTS 425,705 Smallwood Apr. 15, 1890 456,092 Hutchins July 14, 1891 579,583 Jermyn Mar. 30, 1897 742,785 Graham Oct. 27, 1903 1,647,816 Riddel Nov. 1, 1927 2,100,878 Shallock Nov. 30, 1937 2,186,652 Orth et al. Ian. 9, 1940 2,332,600 Rapp Oct. 26, 1943 2,353,941 Stebler July 18, 1944 2,501,403 McKinsey Mar. 21, 1950 2,617,514 Bebinger Nov. 11, 1952 2,792,030 Wahl May 14, 1957 FOREIGN PATENTS 422,-77 1- Great Britain--12.- I an. 17, 1935