US3012674A - Oscillating screen structure - Google Patents

Description

Dec. 12, 1961 HOPPE OSCILLATING SCREEN STRUCTURE 2 Sheets-Sheet 1 Filed June 16. 1958 Dec. 12, 1961 e. HOPPE oscmmmc SCREEN STRUCTURE 2 Sheets-Sheet 2 Filed June 16. 1958 a 57 1 2 41 b m w v W L. a w a b b M a m: F

b v a W D m w r l a m f w v. s c

te tates ice 3,012,674 OCILLATING SCREEN STRUCTURE Gerhard ll-foppe, Frankiiampstrabe 69A, Gelsenkirchen, Germany Filed June 16, 1958, der. No. 742,128 4 (Ilaims. (Cl. 209-491) This invention has reference to screens as used for separating particles of different size.

Oscillating screens or sieves serving the above purpose have often a tendency to become clogged, particularly if the particles to be separated are wet or damp.

It is, therefore, one object of this invention to provide screens for separating particles of different size which have not the tendency to clog.

There are prior art screens wherein the danger of clogging has been successfully avoided. These non-clogging screens are, however, subject to various limitations and/ or drawbacks, and all of them are relatively complicated.

It is, therefore, another object of this invention to provide non-clogging or self-cleaning screens which, though highly effective, are simple, easy to manufacture and inexpensive.

Further objects and advantages of the invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to, and forming part of, this specification.

For a better understanding of the invention reference may be had to the accompanying drawings in which-- FIG. 1 shows in form of an isometric view a screen embodying this invention in combination with a conventional oscillatory frame supporting the same;

FIG. la is a top-plan view of the screen structure of FIG. 1 shown on a larger scale;

FIG. 2 is a top-plan View of a modification of the screen structure shown in FIG. la;

FIG. 3 is a top-plan view of another screen structure having operating characteristics similar to those of the structures of FEGS. 12; and

FIG. 4 is a section along A-A of FIG. 3.

Referring now to the drawings, and more particularly to FIG. 1 thereof, reference letters a have been applied to indicate an upper sieve frame. Upper frame a is supported on a base or base frame 0 by means of four resilient rods or springs e of which but two can be seen in FIG. 1. Frame a supports the screen proper to which reference letter b has been applied. The screen proper has been shown but diagrammatically in FIG. 1. The woven screen structures fully shown in FIG. 1a and FIG. 2 are intended to take the place of the screen proper indicated by reference letter b in FIG. 1. A pair of helical springs f interconnects upper frame a and lower frame c. Lower frame c' is supported by a plurality of springs f" of which but two have been shown in FIG. 1. A shaft g projects transversely across upper frame a and is adapted to be rotated byan electric motor (not shown), supported by frame a. Shaft g supports an eccentric weight d, is. a weight whose center of gravity is spaced from the longitudinal axis of shaft g. As a result. frame a and sieve b will be caused to oscillate, or vibrate, when shaft ,9 and weight d are rotated.

Referring now to FIG. la, the woven wire screen shown therein comprises weft wires interwoven with warp wires. The terms weft wires and warp as applied to the screen shown in FIG. la are intended to indicate that the wires extend at right angles and are interwoven in the fashion of yarn of which textile materials are made. The wires referred to as weft wires may extend either in a direction longitudinally of frame a and in transverse direction. The same applies as to the wires referred-to as warp wires. In FIG. la wires a, b may be considered as weft wires and wires 0 as Warp wires. The woven sieve structure of FIG. la comprises a first system of parallel wires 11 and a second system of parallel wires b. Wires a and b are arranged in parallel and are interleaving, and the stretchability of wires a in a direction longitudinally thereof differs from the stretchability of wires b in a direction longitudinally thereof. The difference in stretchability between the wires a forming a first system of wires and the wires b forming a second system of wires is sufiiciently large to establish a tendency of relative movement between the constituent wires of said first system and the constituent wires of said second system when the screen oscillates under load conditions as an integral part of the structure of FIG. 1, or in an equivalent arrangernent.

The difference in stretchability between the wires a and the wires b may be achieved in a number of ways. Both wires a and b may be made of the same material but their cross-section may differ as indicated in FIG. 1a. As an alternative, the difference in stretchability may be achieved by selecting different materials for wires a and 1). Another means of obtaining twosystems of parallel wires a, b and of establishing a substantial difference in the stretchability thereof is to impart a different bias to the constituent wires of each system, in which case the wires may be made of the same material and have equal cross-sections. As a further alternative for achieving substantially different degrees of stretchability one may resort to auxiliary spring means for controlling the bias of either system of parallel wires a, b as will be more fully explained in connection with FIGS. 3 and 4.

I Referring now to FIG. 2, the wire screen shown therein comprises four systems of wires. Reference character a has been applied to indicate a system of horizontal wires, reference character b has been applied to indicate.

another system of horizontal wires, reference character a has been applied to indicate a system of vertical wires, and reference character b has been applied to indicate another system of vertical wires. Horizontal wires a, b are arranged in interleaving relation and the same applies to vertical wires a, b. The stretchability of horizontal wires a differs from the stretchability of horizontal wires b and the stretchability of vertical wires a differs. from the stretchability of vertical wires b. The constituent wires of the two systems of horizontal wires a, b are interwoven with the constituent wires of the two systems of vertical wires a, b in the fashion clearly shown in FIG. 2.

Referring now to FIGS. 3 and 4, the structure shown therein comprises a first system of parallel wires a and a second system of parallel wires b. Wires b are arranged parallel to and interleaving with wires a. Wires a and b may be made of the same material and may have equal cross-sections. The frame structure for supporting wires a and b includes two parallel bars c made of a relatively inflexible or non-resilient material and four bars e made of a relatively flexible or resilient material. Bars e are arranged below bars 0, and separated from each other by spacer bars 01. A continuous wire a may be wound around bars 0 only, whereas a continuous wire b may be wound around bars e and bars 0, as clearly shown in FIG. 4. The spacer bars (1 are clamped against bars 0, thus preventing unwinding of wire a in case that the same should break at any point thereof. The structure further comprises clamping bars f having lateral grooves g for clamping the turns of continuous wire b against spacer bars d, thus precluding unwinding of the turn of Wire b in case that the same should break at any point thereof. The clamping action of bars d and f is achieved by a number of screws h arranged in spaced relation from each other i and projecting transversely through bars f and d into bars 0.

It will be apparent from the foregoing that though Patented Dec. 12, 196i wires a and b may have inherently the same stretchability in a direction longitudinally thereof, a different stretchability is imparted to wires (1 and b by virtue of the different nature of the terminal supports and e thereof.

The structures shown in the drawings are primarily intended for grading moist coal of relatively small particle size, but may also be used for, and/or adapted for, other purposes.

It will be understood that, although I have shown and described in detail but preferred embodiments of my invention, the invention is not limited thereto, and the illustrated embodiments may be modified and other embodiments made without departing from the spirit and scope or" the invention as set forth in the accompanying claims.

I claim as my invention:

1. In combination a woven screen for separating particles of difierent sizes and means for imparting an oscillatory motion to said screen, said screen comprising weft wires interwoven with warp wires, said weft wires forming a first system and a second system of parallel screen wires, the constituent wires of said second system being arranged parallel to and interleaving with the constituent wires of said first system, the constituent wires of said second system being adapted to have a different stretchability in a direction longitudinally thereof than the constituent wires of said first system, and the difference in stretchability between the constituent wires of said first system and the constituent wires of said second system being sufficiently large to establish a tendency of relative movement between the constituent wires of said first system and the constituent wires of said second system when said screen oscillates under load conditions.

2. In combination a woven screen for separating particles of diiferent sizes and means for imparting an oscillatory motion to said screen, said screen comprising weft wires interwoven with warp wires, said weft wires forming a first system and a second system of parallel wires, the constituent wires of said second system being arranged parallel to and interleaving with the constituent wires of said first system, the constituent wires of said second system being of a material different from that of the constituent wires of said first system, and the properties of the material of the constituent wires of said first system and of the material of the constituent wires of said second system being adapted to establish a tendency of relative movement between the constituent wires of said first system and the constituent wires of said second system when said screen oscillates under load conditions.

3. In combination a woven screen for separating particles of different sizes and means for imparting an oscillatory motion to said screen, said screen comprising weft wires interwoven with warp wires, said weft Wires forming a first system and a second system of parallel Wires, the constituent wires of said second system being arranged parallel to and interleaving with the constituent wires of said first system, and the constituent wires of said second system having a sufficiently different bias from the constituent wires of said first system to establish a tendency of relative movement between the constituent wires of said first system and the constituent wires of said second system when said screen osciilates under load conditions.

4. In combination a woven screen for separating particles of different sizes and means for imparting an oscillatory motion to said screen, said screen comprising a first system of parallel wires and a second system of parallel wires, the constituent wires or" said first system and the constituent wires of said second system being arranged in parallel interleaving relation and being adapted to have a different stretchability in a direction longitudinally thereof, said screen further comprising a third system of parallel wires and a fourth system of parallel wires, the constituent wires of said third system and the constituent Wires of said fourth system being arranged in parallel interleaving relation and being adapted to have a different stretchability in a direction longitudinally thereof, and the constituent wires of said first system and of said second system being arranged at right angles to and interwoven with the constituent wires of said third system and said fourth system.

References Cited in the file of this patent UNITED STATES PATENTS

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