US1545769A - Screening surface - Google Patents

Description

' July 14, 1925.

J. L. HILL-ER SCREENING SURFACE Filed Aug. 20,

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JOSEPH. L. I-IIIJLER, .MATT-APOI$ETT, MASSACHUSETTS.

SCREENING 1 SURFACE;

Application filed August 20, .1921. Serial No. 494,025.

To all whom it may concern:

Be it known that I, Josnrri L. HILLER,

a citizen of theUnited States, residing at ."Mattapoisett, in the county of Plymouth and State of "Massachusetts, have invented certain new and useful Improvements in 'Screenii'ig Surfaces, of which the following thematerial to be screened asto promptly and favorably present all of thematerial in such a manner as to cause, in theshortest possible time, the elnnmation of those pieces .sma'll enough to pass through the screen and, therefore, in screenmg, to promote those valuable advantages of maximum capacity,

thoroughness of classification and reduction ,incost of operation resulting from the improved qualities of the screening surface. Another important object to be attained is to secure the passage through the screen of flat pieces, sufliciently thin to pass through the screen edgewise and yet so wide as to prevent their passage through the-screen flatwise.

My invention consists of a screen of the cascade type, in which the material passing over the successive cascades is tumbled and stirred so as to present the pieces of material in constantly changing new arrangements, thus quickly presenting in a favorable position for discharge each piece small enough to be eliminated.

Referring to the drawings, Fig. 1 rep resents a perspective View of a portion of such a screening surface as is contemplated by my invention. Fig. 2 shows a plan View of such a screening surface and Fig. 3 represents a side elevation of Fig. 2.

Referring now to the several views of the drawing, the numeral 2 indicates projecting members, accordingto my invention, on the first and on the third series of cascades in which series 3 represents the cascading portion of the first and the third series of cascades and which portions (3) are of the type of the prior art. The projections marked 2 are, likewise, representative of a feature of my invention being shown on the second and fourth series of cascades. Similarly 3 shows cascading portions of the old types, on the second and fourth series of cascades. The spacing washers 4 shown in .1 are not shown in Fig. 2. Similarly the; rods 5 on which the screen shown in -Fig. lisassembledare omitted from Fig.2

and Fig. 3.

. It Wl-ll' be' noted" that in the arrangement which -I'have shown, theiwlre screenbars I have aprojecting cascading member oneach alternate cascading portion of the screen bar, and that these screen bars (are soiassem'bled that apro ecting cascadmgmmember alternates witha plain cascading member in each cascading series extending across the screen.

It is evident that the proportion of projectingmembers may .be varied and that the length of the projecting members may be altered to suit the character ofthe material to be classified.

It willbe observed that the projecting members of the screen areiso tapered that,

.llongitudinally with :the travel, the thickness of these members is decreased and the width of spaces rbetween=sald members ,is increased thereby, and by thus avoiding-the possibility ofnarrowingthe. spaces inthe direction of travel ofmaterlal, the screen is free from clogging. Although the taper of the screen bars tends toxmake a clean working and ef- -fect1ve screen, thls. feature. 1s notclaimed as a part of this invention, except as'to the proj ecting members.

In operation, the pieces of material pass longitudinally over the screen and the eascading effect upon the material brings fresh pieces in contact with the screenmg surface. The projecting members have two functions. The first is useful in general screening operations because of its action in elevating or pushing up through the mass those pieces of material which are of larger size. The action of these projecting members will, in effect, be similar to the action of a series of parallel bars arranged lengthwise of the travel and intermittently proj ected upwardly through the mass, thus lifting the larger piecees of material and maintaining them on top of the blanket of material passing over the screen. The second function of these projecting members is of advantage in separating the thin fiat pieces from the pieces having a cubical or spherical tendency for, as a flatpiece passes over the screening surface between the cascades, the flat side will usually lie upon the screen and in passing over one of these projections the piece will be tilted to one side or the other, in which process it is turned up edgewiseand if thin enough will pass through the screen. If such a flat piece happens to flow between two of these projecting members on one cascade it will, on account of the alternate longitudinal occurrence of the projections, come in contact with a projecting member on the next, or some subsequent, cascade and thus be tested and classified. It will thus be seen that the alternate arrangement of the projections is such as to insure or facilitate the proper reticulation of each piece of material, so as to secure its proper classification. It will also be observed that the larger pieces of material which are lifted from the general screening surface by the projecting members will be delivered to the projecting members on the successive cascades with scarcely any opportunity of touching the intervening general surface of the screen.

This type of screening surface is adapted for use either as a relatively flat screen which may be stationary and so inclined as to permit screening'by the action of gravity, or it may be given a reciprocating motion to facilitate the passage of material over a screen which is less inclined, or it may be curved into a cylinder, or it may be adapted to suit the conditions of variously arranged special screens.

The type of construction which I have shown is well suited to manufacturing methods employing electric welding apparatus which results in a cheap, rugged and reliable product. The screen illustrated in the drawings is provided with wire bars spaced apart by means of washers on the rods which pass through loops in the wires. This looping of the longitudinal wires is not, however, an essential construction and, in some instances, may not be as cheap or as desirable as a bar having some other form of support. While I show a screen made form wire, my invention is not limited to wire screens, for castings, forgings, stampings or other forms of construction may be utilized with good effect.

What I claim is: s

1. A screen consisting of bars, being formed with a series of bends in planes perpendicular to the general surface of said screen and said bars having projections intermediate, longitudinally of certain of said bends and continuing the planes, on one side of said bends a distance in excess of the height of said projections above the planes of the screen on the other side of said bends.

2. A screen consisting of a series of cascades, on bars, arranged in rows, transverse of said bars, with projections on alternate bars extending forward, in the dircction'of said cascades, said projections extending from points approximately in line with the brows of said cascades.

3. A screen consisting of a series of cascades, on bars, arranged in rows, transverse of said bars, having tapered projections on non-adjacent bars, extending forward, in the direction of said cascades, said projections extending from points approximately in line with the brows of said cascades.

In testimony whereof I have afiixed my signature in the presence of two witnesses.

JOSEPH L. HILLER. Witnesses:

A. WV. WILLMANNS, HANNAH MACKOWITZ.

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