US2345947A - Screening apparatus - Google Patents

Description

April 4, 1944. w. J. PARKS SCREENING APPARATUS 3 Sheets-Sheet 1 Filed March 5, 1942 WALTER J. PEXEN BY ATTORNEYS April 4, 1944- f w. J. PARKS SCREENING APPARATUS Filed March 5, 1942 3 Sheets-Sheet 2 INVENTOR. WALTER J. PARKS. BY @W 11 1M WMJMMM April 1944- w. J. PARKS SCREENING APPARATUS Filed March 5, 1942 5 Sheets-Sheet 3 WALTER VJ. s y BY 52%? @M,

ATTORNEYS,

Patented Apr. 4, 1944 to The W. S. Tyler Company, Cleveland, Ohio, a corporation of Ohio Application March '5, 1942, Serial No. 433,415

Claims; (01. 209-408).

This invention relates, as indicated, to screening apparatus, but has reference more particularly to the construction of the screen supporting structure of such apparatus.

It has heretofore been customary to construct the screen decks or screen-supporting frames of screening apparatus of angles, channels and H- beams, extending continuously from side plate to side plate of the apparatus, the particular structural section selected with a View to the necessary strength and stiffness required by the width of the screen and the loads to be carried. This required the stocking of a wide variety of different sections, as will be evident from the fact that the stiffness and strength required for any given installation increases very rapidly, i. e., as the fourth power of the width of the screen.

Moreover, each of the structural sections referred to has a flange or leg of considerable width, which, when disposed immediately below the will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this specification, and in which like numerals are employed to designate like parts throughout the same.

screen cloth, blocks oif a considerable portion of l the effective screening area. The material which passes through the screen cloth causes rapid wear at the outer, and usually thinner, edges of such flanges, resulting in a notching of the flanges,

and causing premature fatigue failure ofthe entire structural member. V

It has also been customary to incorporate these transversely extending structural members into a welded frame or panel by adding thereto side members, which are secured to the side plates of the screen, as Well as bridge rails or members which extend longitudinally of the structure and serve to support the intermediate portions of the screen. This construction requires considerable labor in the laying out and fabrication of the individual members, as well as agreat deal of time for assembling, welding and straightening the panels after welding. The panel has a great number of welds incorporated therein, and if the metal is burnt or otherwise damaged atany one weld, and a failure occurs at this point, it causes failure at adjacent points in the panel, requiring replacement of the entire panel;

The present invention has as its primary ob ject the provision of a screen supportingstructure which overcomes all of the foregoing disadvantages and defects of existing structures, which provides a maximum of open space for screening purposes which is wear-proof and distortionproof, and which is efiective to prevent movement of the side plates of the screen'relatively to one another, as well as buckling or bending of the side plates. r

Another object ofv the invention is to provide a structure of the character described, which is made up of basic elements or units, so constructed as to facilitate arrangement thereof to form screen decks o f any desired length. 1 Qther obiects andadvantages of the invention In said annexed drawings:

Fig. 1 is a front end elevation of a screening apparatus embodying the invention;

Fig. 2 is a side elevation of the screening apparatus;

Fig. 3 is a longitudinal cross-sectional view of the apparatus, taken on the line 3-3 -of Fig. 1;

Fig. 4 is a transverse cross-sectional view taken on the line 4--4 of Fig. 2;

Fig. 5 is an isometric view of one of the screening decks of the apparatus;

Fig. 6 is a front elevation of one of the principal structural elements of the deck; Fig. 7 is a cross-sectional View, taken on the line 1-1 of Fig. 6; and V Fig. 8 is a top plan view of the structural ele ment. j l

Referring more particularly to the drawings, the screening apparatus comprises, in general, a gyrating screen body I, resiliently supported upon a stationary base frame 2, and adapted to be gyrated by means of an eccentric shaft assembly 3, the construction andoperation of which is substantially the same as that described in my Patent No. 2,066,362.

Although the invention is shown as embodied in a gyratory screening apparatus of the type referred to, it will be understood that it may be incorporated in othertypes of screening apparatus having a gyratory or vibrating movement.

The screen body I consists of a pair of transversely spaced side plates 4 and 5, to which .are secured, as by means of bolts 6 and nuts l, side rails 8, which serve to stiffen or reinforcethe side V plates and provide supports for the edgesof the screen cloth 9. In this particular application, the screen cloth has hooked edges which are engaged by. packing strips l0, these strips being in turn engaged by bolts H which extend through elongated openings l2 inthe side plates and through angle boxes l2a, the bolts being retained in position by means of nuts iZb. The strips, bolts and nuts thus serve to stretch the screen cloth.

Extending transversely of the screen? body at the feed end thereof is an angle beam 13 having welded to the ends thereof angle clips l4, which are secured to the side rails 8 by bolts and nuts which secure the ends of the side rails to the side plates. Secured to the horizontal flange of the beam I3 is a back plate l5, which serves to prevent the material being screened from spilling over the rear end of the screen body. Extending transversely of the screen body at the discharge end thereof is an angle beam 16 having welded to the ends thereof angle clips" ll,

which are secured to the side rails 8 in the same manner as the clips I4, the beam it having a horizontal flange lta extending forwardly of the screen body to provide a discharge lip for the material being screened.

Secured to the vertical flanges of the side rails.

body has the portion IBa thereof secured to the beam I3 by means of bolts which pass through the perforations H! (see Fig. 7). Similarly, the element I8, at the discharge end of the screen body, has the portion I8a thereof secured to the beam I6 by means of bolts which pass through the perforations l9.

Extending longitudinally of the screen body at transversely spaced points are bridge rails 20, provided at their ends with flanges 2| secured to the portions l8a of the elements 18 by means of the same bolts which are employed to secure these elements to the rails l3 and I6 and to each other.

Mounted on the bridge rails are suitable coverings or strips 22, of rubber Or like material, which serve as supports for the intermediate portions of the screen cloth 9, maintaining such cloth in a bowed condition, as shown in Fig. 4.

It will be noted in Fig. 5 that the elements 8, l3, l6, l6 and 20 form a unitary rigid structure, which is characterized by the following advantageous features: (a) The structure provides a maximum of open space for screening purposes, being substantially free from flanges or legs which might obstruct the flow of screened material therethrough. (b) The X-beam units consisting of the back-to-back elements [8, as well as the end elements H3 in association with the beams I3 and I6, are eifective not only to resist weaving of the structure, that is, movement of one side of the structure relatively to the other in the plane of the structure, but also to prevent distortion of the structure, that is to say, movement of one portion of the structure in a direction normal to the plane of the structure. By preventing such weaving and distortion of the structure, movement of the side plates relatively to one another is effectively prevented. These advantages are particularly desirable in a long screen of single deck construction. like structures formed by the elements 8, [8b and the outermost bridge rails 20, and which structures extend substantially the entire length of the structure, are effective to prevent buckling or bending of the side plates. This is especially important in long screens of 18 to 20 feet in length.

Using the elements [8 as a basic unit, and arranging them in various multiples and spacings, screen decks of any desired length'can be built up. For screens of different width changes in the depth and weights of the elements I8 will, of course, be required, but the elements will, in all cases, be of substantially the same construction. In the present case, the angle between the portion 18a and the portions IBb of the elements i8 is approximately 45, but other angles may be used, if desired. Moreover, instead of forming the ele- (c) The trussments l8 from plain bar stock, they may be formed from laminated bars or a series of nested bars, or, if desired, they may be formed from channels or other structural sections. In the latter case, however, there would of necessity, be some sacrifice in the effective open area of the structure for screening purposes. Furthermore, instead of bolting the various elements of the structure together, the elements could, after being assembled, be welded, riveted or otherwise secured together, or the structure could be made up in sections, portions of which have previously been assembled into units.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. In a screening apparatus, a screen supporting structure comprising spaced side rails, and a plurality of longitudinally spaced beams interconnecting said side rails, each of said beams comprising a pair of elements having central portions in back-to-back relation with the backs disposed in a plane substantially perpendicular to the general plane of said structure, and diverging portions extending angularly to said central portions and connected to said side rails.

2. In a screening apparatus, a screen supporting structure comprising spaced side rails, and a plurality of longitudinally spaced beams interconnecting said side rails, each of said beams comprising elements arranged in back-to-back relation and having portions extending angularly to the back-to-back portions and portions parallel with and secured to said side rails, said backto-back faces being disposed in a plane substantially perpendicular to thegeneral plane of said structure.

3. In a structure, as set forth in claim 2, bridge rails interconnecting the back-to-back portions of said beams.

4. In a screening apparatus, a screen supporting structure comprising a rectangular frame, including spaced side rails, and a plurality'of longitudinally-spaced beams interconnecting said side rails, eachof said X-beams comprising a pair of elements having central portions of substantial length in back-to-back relation and extending substantially perpendicular to said side I rails, and diverging portions of lesser length than said central portions extending angularly to said central portions and to said side rails, said backto-back faces being disposed in a plane substantially perpendicular to the general'plane of said frame. v r V V 5. In a screening apparatus, a screen supporting structure comprising a rectangular frame, including spaced side rails, and a plurality of longitudinally-spaced beams interconnecting-said side rails, each of said beams comprising a; pair of elements having central portions of. substantial length in back-to-back' relation and extende ing substantially perpendicular to the side rails,

and diverging portions extending angularly to said central portions and to said siderails; said 7 central portions having a cross-section presenting a short dimension and a long dimension, the long dimension extending substantially perpendicular to the plane of said frame and the shortdimen sion adapted to support thereon a screen.

-' WALTER J. PARKS;

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