US3716138A

US3716138A - Screen

Info

Publication number: US3716138A
Application number: US00036974A
Authority: US
Inventors: A Lumsden
Original assignee: Hoyt Wire Cloth Co
Current assignee: Hoyt Wire Cloth Co
Priority date: 1970-05-13
Filing date: 1970-05-13
Publication date: 1973-02-13
Anticipated expiration: 1990-02-13

Abstract

A vibrating screen woven with wire having an elliptic or oval cross section with a vertical dimension substantially greater than the horizontal dimension. In the manufacture of the screen, the individual wires are crimped prior to weaving so as to control the size of the openings provided by the interstices of the weave. The openings may have an outline which is square, rectangular (normally called oblong), or a combination (normally called long-slot) combining elongated rectangular openings with square openings.

Description

United States Patent [191 Lumsden SCREEN [75] Inventor: Alexander D. Lumsden, Lancaster,

[73] Assignee: Hoyt Wire Cloth Company, Lancaster, Pa.

221 Filed: May 13, 1970 21 Appl. No.: 36,974

[52] US. Cl ..209/40l, 139/425 R, 245/8 [51] Int. Cl. ..B07b l/46 [58] Field of Search ..209/402, 401, 392; 210/499;

' 139/425 R; l62/DIG. 1; 245/2, 8; 140/6, 7, 9

[ 1 Feb. 13, 1973 2,874,730 2/1959 Pomeroy 140/7 X 3 ,545,705 12/1970 Nodsson ..245/8 FOREIGN PATENTS OR APPLICATIONS 12,140 5/1898 Great Britain 139/425 576,939 6/1959 Canada ..245/2 OTHER PUBLICATIONS Robins Publication, pg. 5 (non-blind), 1942.

Primary Examiner-Frank W. Lutter Assistant Examiner-Robert I-Ialper Attorney-Howson and I-Iowson [5 7] ABSTRACT A vibrating screen woven with wire having an elliptic or oval cross section with a vertical dimension sub stantially greater than the horizontal dimension. In the manufacture of the screen, the individual wires are crimped prior to weaving so as to control the size of the openings provided by the interstices of the weave. The openings may have an outline which is square, rectangular (normally called oblong), or a combination (normally called long-slot) combining elongated rectangular openings with square openings.

8 Claims, 1 1 Drawing Figures PATENTEUFEB 13 1925 3.716; 138

SHEET 1 OF 3 INVENTOR: ALEXANDER D. LUMSDEN WWW ATTY S.

- 'PATENIEDFEB 1 3 I975 3.716.138

- sum 2 [IF 3 INVENTOR; ALEXANDER o. LUMSDEN ATTYS PATENTEUFEB13|975 3.716.138

SHEET 3 OF 3 INVENTOHI ALEXANDER D. LUMS DEN WWW AT'n s.

SCREEN The present invention relates to screens, and has particular application to the woven wire cloth in a vibratory screen which is used for classifying the material flowing therethrough or thereover.

Wires of various shapes have been used in the manufacture of wire belts, sieves, and other woven wire fabrics, but the expense of the special shaping of the wire, when combined with the cost of assembling the same into a cloth have made their use in vibrating screens impractical.

In accordance with the present invention, it has been discovered that an elliptic or oval configuration of wire enables the use of standard fabricating techniques without excessively increasing the cost of manufacture and assembly of the woven wire into the vibrating screen apparatus. The particular configuration and arrangement of the wires in the screen enables the production of a wire cloth which has improved re sistance to wear without sacrificing the volume of flow through the screens and the ability of the screens to classify the desired quantity of material. Conversely,

the invention enables the production of a wire cloth which has improved volume of flow through the screens without sacrificing resistance to wear. Additionally, both the wear and volumetricflow may be improved.

The invention provides a novel vibrating screen which is highly efficient in operation and fully effective in use.

All of the objects of the invention are more fully set forth hereinafter with reference to the accompanying drawing wherein:

FIG. 1 is a view in side elevation ofa vibrating screen apparatus embodying the present invention;

FIG. 2 is an end elevation as seen from the'line 2-2 of FIG. 1;

FIG. 3 is an enlarged detail illustrating the mounting of the wire cloth in the apparatus of FIGS. 1 and 2;

I FIG. 4 is a plan view of the cloth shown in FIG. 3;

FIG. 5 is a local longitudinal sectional view of the cloth as taken on the line 5-5 of FIG. 4;

FIG. 6 is a greatly enlarged cross section taken on the line 66 of FIG. 4;

FIG. 7 is a view similar to FIG. 4 of an alternate embodiment of cloth embodying the present invention;

FIG. 8 is a longitudinal sectional view taken on the line 8-8 of FIG. 7; FIG. 9 is a greatly enlarged sectional view taken on the line 9-9 of FIG. 7;

FIG. 10 is a view similar to FIGS. 4 and 7 ofa further embodiment of the cloth made in accordance with the present invention; and.

FIG. 11 is a longitudinal sectional view taken on the line 1lll ofFIG. 10.

Referring now to FIGS. 1 through 3,'the vibrating screen apparatus of the present invention comprises a main support 12 havinga vibrator 13 mounted thereon so as to impart vibrations to the apparatus which is suspended by conventional

spring suspension devices

14 and 15. The support 12 carries a series of decks designated 16, 17, and 18 in FIG. 2, each deck comprising a sized screen cloth l9 tensioned between tension plates 20 along the opposite sides of each deck. As shown in FIG. 3, the selvages of the screen cloth 19 include reinforcing angles 21 to accept and distribute the load of the tension plates 20.

In accordance with the invention, the screen cloth 19 is formed in both the wrap and the weft directions of elliptic or oval shaped wire having a cross section whose height is greater than its width and exhibiting a rounded upper and lower surface. In FIG. 4, the warp wires are designated by the reference characters 25 and the weft wires are designated by the reference characters 26. In the screen shown in FIG. 4, the warp wires and the weft wires are identical in cross section and are crimped identically as shown in FIG. 5 to form a series of upwardly projecting knuckles 27 and downwardly facing knuckles 28. In FIG. 5, the

knuckles

27 and 28 are shown in the warp wire 25, but it is apparent that the weft wire 26 has corresponding knuckles, the upper knuckles 29 of the weft wires being nested with the lower knuckles 28 of the warp wires and the lower knuckles 30 of the weft wires nested with the upper knuckles 27 of the warp wires.

Not only are the warp wires 25 identical in crimping to the weft wires 26, but also the cross sections of the two wires are identical. As shown in FIG. 6, the cross section of each wire has a height A which is greater than its width B and the cross section provides rounded upper and

lower surfaces

33 and 34 interconnected by

straight side surfaces

35 and 36. In the present instance, the

surfaces

33 and 34 are substantially cylindrical in form having a constant radius of curvature as indicated at R. These curved surfaces merge tangentially into the straight

side wall surfaces

35 and 36 so as to provide a substantially smooth contour about the entire periphery of the wire.

The

flat side walls

35 and 36 confront the corresponding flat walls of the adjacent wires, the surfaces of the weft wires confronting one another in spaced parallel relation as shown in FIG. 5 and the surfaces of the warp wires likewise confronting one another in spaced parallel relation. The spacing of the confronting

flat side walls

35 and 36, determines the mesh opening as indicated at M in FIG. 5. The rounded upper surfaces 33 of the wires direct the material through the mesh openings, the confronting flat surfaces of these openings providing a passageway of the width M for the full thickness of the screen.

The mesh opening M is maintained at the proper size for a substantially longer period than is the case in standard screens where the initial wear in the screen inherently increases the size of the mesh opening by wearing away the material defining the side walls of the opening. With a wire of the present invention, however, the

flat portions

35 and 36 extend the life of the opening since the entire surface must be worn away before the effective size of the opening is modified. It is understood that the major wear of a screen of this character is along the upper surfaces of the upper knuckles of the screen since it is the larger particles which do not pass through this screen which exert the greatest erosion force upon the material of the screen. Thus the particular form of wire in the screen contributes substantially to extending the useful life of the screen beyond that which is obtained with screens of conventional design.

Furthermore, since the walls of adjacent wires in the weft and the warp direction are spaced parallel to one another, there is little tendency for particles to become wedged between the walls and the blocking of the mesh openings by material is minimized.

The invention is not limited to screens having a square mesh as shown in FIG. 4, but other types of screens may be made in accordance with the present invention. FIG. 7 shows a so-called oblong mesh screen in which the mesh openings are rectangular in form. In this wire screen, the weft wires 46 are slightly larger than the warp wires 45 because of the greater wear to which the weft wires are subjected and the upper and

lower knuckles

47 and 48 formed in the warp wires 46 are offset alternately upwardly and downwardly from the intermediate runs 49 which are positioned between the knuckles. The weft wires 46, on the other hand, have upper and lower knuckles contiguous to one another substantially as is the case in connection with the weft wires 26 of the previously described embodiment.

In the embodiment of the invention shown in FIGS. 7 through 9, for the purpose of illustration, the wires have a configuration in cross section similar, but not identical, to the cross sectional configuration of the wires in the previous embodiment. With reference to FIG. 9, the wires have arcuate upper and

lower surfaces

53 and 54 respectively which are connected by

flat side walls

55 and 56. Whereas in the previous embodiment, the arcuate surfaces merge tangentially with the flat side walls, in the present instance the arcuate surfaces intersect the

side walls

55 and 56 to provide a definite line of demarcation.

The distinction between the wires shown in FIGS. 6 and 9 resides in the manner of providing the elliptic or oval cross section. In the embodiment shown in FIGS. 4 through 6, the wires are initially formed into the oval shape shown in FIG. 6 and are subsequently crimped to provide the knuckles. In the embodiment shown in FIG. 9, on the other hand, the wires are round and are crimped when in the round state. Subsequent to crimping, the round cross-section of the wires is flattened by passage through suitable forming apparatus so as so impart to the wires the flattened

side walls

55 and 56 between the arcuate upper and

lower surfaces

53 and 54. Whether the wire is formed as shown in FIG. 6 or as shown in FIG. 9, has no effect upon the functional characteristics of the vibrating screen apparatus. However, as will be recognized, the work operations upon the wire determine the character of the alloys used to make the wire, and these alloys, in turn, determine certain functional wear characteristics of the wire.

Another embodiment of the invention is shown in FIG. in which the wire screen is a so-called long slot screen. In this embodiment of the invention, the warp wires 65 are maintained in spaced parallel relation by weft wires 66 arranged in groups of three at spaced intervals along the length of the warp wires. As in the embodiment shown in FIGS. 7 through 9, the weft wires 66 are larger than the warp wires 65. In this embodiment of the invention, the warp wires are crimped to provide upper knuckles 67, lower knuckles 68, and runs 69 intermediate the groups of weft wires. In the form illustrated in FIG. 11, the upper knuckles 67 are on a level with the intermediate runs 69 so as to provide a smooth-top wire screen in which the upper knuckles 67 of the warp wiresand the upper knuckles of the weft wires 66 are substantially coplanar with the intermediate runs 69, so that the upper surface of the wire screen is substantially flat. In other respects, the long slot wire screen is similar to the oblong wire screen shown in FIG. 7, but the elongated mesh openings are correspondingly narrower in rectangular shape, and square mesh openings are produced within the grouped weft wires between the elongated openings.

The screens illustrated in this application have utility not only in vibrating screen apparatus of the type shown in FIGS. 1 to 3, but also have application for usage in sizing, separating, cleaning, dewaterization in the mining and quarry and mechanical industries. The screen provides a greater ratio between the area of the mesh openings and the total area of the screen so that a more efficient operation is provided. Likewise the screen provides a greater effective wear life than is possible with screens of conventional construction.

For the purposes of classification, the dimensions A and B of the wire, as shown in FIG. 6, are preferably standard wire diameters, the dimension B being between one and four wire sizes smaller than the dimension A. The dimension A ranges between 1.000 inch and 0.032 inch, and the dimension B ranges between 0.750 inch and 0.028 inch, with the B dimension at least one and not more than four wire sizes smaller than the A dimension. The standard wire sizes are as follows:

1.000" .3l25" .177" .105" .054" 0.750" .250" .l62" .092" .047" 0.625" .225" .148" .080 .04l" 0.500" .207" .l35" .072" .035" 0.4375" .192" .120" .063" .032" 0.375"

The embodiments of the invention illustrated herein are intended to be exemplary and should not be considered to be exhaustive of the screen construction. For example in the illustrations, the warp and weft are crimped to the same depth. However, it frequently is desirable to crimp the weft wire deeper than the warp wire. In certain installations, it may be desired to use round wire in the weft, particularly in long slot specifications. Furthermore, in the oblong and long slot cloth, the illustrated forms use a larger weft wire; however, the specifications frequently require the wire to be of uniform size throughout.

While particular embodiments of the present invention have been herein illustrated and described, it is not intended to limit the invention to such disclosures but changes and modifications may be made therein and thereto within the scope ofthe following claims.

I. For use in vibrating screens, wire cloth screening composed of warp wires and weft wires interwoven to produce an integral wire cloth structure, said warp wires and weft wires being crimped to provide upper and lower pre-formed knuckles, the upper knuckles of the warp wires being nested in the lower knuckles of the weft wires, and vice versa, the height of the crimps being equal in the warp and the weft wires so that the upper surface of said screening provides coplanar upper knuckles of said warp wires and said weft wires, the cross section of each of said wires having arcuate upper and lower surfaces and at least two flat side walls intermediate said arcuate upper and lower surfaces and being of uniform dimension throughout without notches, the flat side walls of adjacent weft wires being disposed in spaced relation to define the length dimension the mesh openings therebetween, and the flat side walls of adjacent warp wires being disposed in spaced parallel relation to define therebetween the transverse dimension of the mesh openings, the height dimension of said wire cross section being between one and four wire sizes larger than the width dimension of the wire cross section in both the warp wires and the weft wires of the screen.

2. Woven wire screening according to claim 1 wherein the mesh openings in said screen are square, the upper and lower knuckles in each wire, both weft and warp, being contiguous.

3. Woven wire screening according to claim 1 wherein said mesh openings are rectangular in form, the upper and lower knuckles of the weft wires being contiguous, and selected upper and lower knuckles of the warp wires being spaced apart by an elongated intermediate run to define a rectangular opening.

4, Woven wire screening according to claim 3 wherein said weft wires are grouped in groups of three, said elongated runs being disposed intermediate the groups of weft wires.

5. Screening according to claim 3 wherein the upper knuckles of said crimped warp and weft wires project above the intermediate runs, and the lower knuckles of said warp and weft wires project below the intermediate run.

6. Screening according to claim 3 wherein the upper knuckles of said warp and weft wires are substantially coplanar with said intermediate runs and said lower knuckles of the warp and weft wires project below said intermediate runs whereby said screen has a smoothtop appearance.

7. Screening according to claim 1 wherein said woven screen cloth includes angle elements extending along opposite edges thereof for anchoring said screen into vibrating screen apparatus.

8. For use in vibrating screens, wire cloth screening composed of a set of warp wires and a set of weft wires interwoven to produce an integral wire cloth structure, said sets being crimped to provide upper and lower preformed knuckles, the upper knuckles of one set being nested in the lower knuckles of the other set, and vice versa, the height of the crimps being equal in the warp and the weft wires so that the upper surface of said screening provides coplanar upper knuckles of said warp wires and said weft wires, the cross section of each of the wires being of uniform dimension throughout without notches, the cross section in at least one set having arcuate upper and lower surfaces and at least two flat side walls intermediate said arcuate upper and lower surfaces, the sides of adjacent weft wires being disposed in spaced relation to define the length dimension of the mesh openings therebetween, and the sides of adjacent warp wires being disposed in spaced parallel relation to define therebetween the transverse dimension of the mesh openings, the height dimension of said cross section in said one set being between one and four wire sizes larger than the width dimension of said cross section.

Claims

1. For use in vibrating screens, wire cloth screening composed of warp wires and weft wires interwoven to produce an integral wire cloth structure, said warp wires and weft wires being crimped to provide upper and lower pre-formed knuckles, the upper knuckles of the warp wires being nested in the lower knuckles of the weft wires, and vice versa, the height of the crimps being equal in the warp and the weft wires so that the upper surface of said screening provides coplanar upper knuckles of said warp wires and said weft wires, the cross section of each of said wires having arcuate upper and lower surfaces and at least two flat side walls intermediate said arcuate upper and lower surfaces and being of uniform dimension throughout without notches, the flat side walls of adjacent weft wires being disposed in spaced relation to define the length dimension the mesh openings therebetween, and the flat side walls of adjacent warp wires being disposed in spaced parallel relation to define therebetween the transverse dimension of the mesh openings, the height dimension of said wire cross section being between one and four wire sizes larger than the width dimension of the wire cross section in both the warp wires and the weft wires of the screen.

4. Woven wire screening according to claim 3 wherein said weft wires are grouped in groups of three, said elongated ruNs being disposed intermediate the groups of weft wires.

6. Screening according to claim 3 wherein the upper knuckles of said warp and weft wires are substantially coplanar with said intermediate runs and said lower knuckles of the warp and weft wires project below said intermediate runs whereby said screen has a ''''smooth-top'''' appearance.