US3285413A - Screen apparatus - Google Patents

Description

E. J. TAYLOR-SMITH SCREEN APPARATUS 5 Sheets-Sheet l mm, m5 Q NQ 1m my W 1 o o R y. l m

mw o MJ v Nov. 15, 1966 Filed March 23, 1964 Nov. 15, 1966 E. J TAYLOR-SMITH SCREEN APPARATUS 5 Sheets-Sheet 2 Filed March 23, 1964 INvzNron ERNEST J. mYLOR-SMITH ATTO NEYG NW- 15 1966 E.J.' TAYLOR-SMITH 3,285,413

SCREEN APPARATUS Filed March 25, 1964 5 Sheeis-Sheet 5 lNVENTOR gl/ j l A ERNEST 1; TAYLOR-sMl'rH United States Patent Office 3,285,413 Patented Nov. 15, 1966 3,285,413 SCREEN APPARATUS Ernest J. Taylor-Smith, Vancouver, British Columbia,

Canada, assignor to Selectors Aggregates Co. Ltd.,

Vancouver, British Columbia, Canada, a corporation of British Columbia, Canada Filed Mar. 23, 1964, Ser. No. 354,036 11 Claims. (Cl. 209-315) This invention relates to screen apparatus for screening material such as gravel, crushed rock Iand the like, and has for its particular purpose the object of producing, from an agglomerate mass of material, ranging from ne to coarse and in which elongated particles commonly called shards are found, particles of substantially uniform size and shape. In the specication and claims hereinafter the word shape shall be deemed to define particles having relatively the same length, breadth and width as opposed to those particles hereinafter called shards, having one dimension, elongated.

It is appreciated that certain apparatus has hereinbefore been designed to produce the material above specilied. However, such apparatus, usually of the vibratory incline screen type, has limits imposed thereon relative -to the degree of inclination of the screen and upon the period and amplitude of vibration thereof. These limiting factors in turn limit the production of the machines and are not suitable for use with all types of material. The eiciency of machines hereinbefore has also been 4reduced by the moisture present in the material to be screened, the proportion of fines to coarse and the relative densities of the material handled. The present screen apparatus Ialso being of the inclined vibratory type overcomes the objections heretofore mentioned by providing a means whereby shards are automatically and positively rejected independently of the degree yof inclination of the apparatus or upon the period of amplitude of the vibration thereof. The present machine is also not limited by the water content of the material treated nor of the relative densities of the individual particles making up the mass. The capacity of the present apparatus is therefore limited only by its over-all size.

The present invention comprises an inclined vibratory screen arranged to receive the material at its upper end, said screen having particle passing apertures of uniform dimension, ejector means comprising a plurality of particle engaging surfaces arranged below and `substantially parallel with the screen so that one of said surfaces lies directly fbelow to `a corresponding aperture, each of said surfaces being spaced below said screen a distance substantially equal to the aperture dimension, means to actuate the ejector means in a direction normal to the plane of the screen to thereby eject upwardly onto the surface of the screen shards having one dimension greater than the aperture dimension as said shards attempt to pass through the apertures, and a second inclined vibratory screen arranged below the ejector screen to receive material passed by the first vertical screen, said second screen having apertures of smaller dimension than said rs-t-rnentioned screen.

Referring to the drawings which illustrate the embodi- -ments of the invention,

FIGURE 1 is a plan View of the apparatus in which certain elements thereof are partially cut away,

FIGURE?. is a side elevation of the apparatus in which certain elements thereof have -been cut away,

FIGURE 3 is a section taken along line 3 3 of FIG- URE 1,

FIGURE 4 is a fragmentary section showing the disposition of the screen elements of the apparatus, and

FIGURE 5 is a diagrammatic representa-tion of the apparatus in elevation showing the ow of material thereover.

Referring to the drawings, the apparatus generally numbered 1()` comprises a pair of longitudinal side members 12, to each of `which a pair of upright supporting members 15 are secured centrally thereof, said members being mounted in an inclined position on transverse stringers 16. Mounted on the top lof the upright supports 15 are a pai-r of bearing blocks 18 which rotatably support a transverse shaft 19, the central portion 21 of which is eccentric to the yaxis of rotation of said shaft, the latter having a pulley 23 iixedly secured at one end thereof.

A pair of bearing blocks 25 similar to bearing blocks 18 are mounted below the latter on side members 12 to rotatably support a transverse shaft 27 also having a central portion 28 eccentric to the rotational axis of the latter much in the same manner as has transverse shaft 19. Transverse shaft 27 also has a pulley 29 xedly secured near one end thereof and connected to pulley 23 by a belt 31. Transverse shaft 27 and with it transverse shaft 19 are driven by a pulley 32 iixedly connected to the outer end of transverse shaft 27 and driven by a belt 33, the latter being connected in a suitable manner to any suitable source of power, not shown.

Mounted between the upright supports 15 also in an inclined position are overlapping tandem screens 35 and 36, tandem ejectors 37 and 38, and a screen 39, said screens and ejectors having a connection, in a manner to be described hereinafter, to the central portions 21 and 28 of the transverse shafts 19 and 27, respectively.

Each of the screens 35 and 36 comprises an aperture plate 40, shown in cross section in FIGURE 4, the apertures 41 being of uniform shape, that is, either round or square, and -arranged in spaced rows running longitudinally of the apparatus, each of the rows of apertures in screen 35 being staggered relative to the apertures in screen 36. Each of said screens has formed as an integral part of or secured as by welding to the underside of the web of the plate lying between said apertures, a plurality of longitudinal triangular shaped ribs 44.

Each of the screens 35 and 36 is mounted at its longitudinal edges between a pair of vertical side panels 46 extending longitudinally of the apparatus, said side panels extending above and below the screens and having transverse supports 48 secured between their ends so that 'the panels and transverse supports form a rigid frame 49. As hereinbefore noted, the screens 35 and 36 are mounted in an inclined tandem position, the lower edge of the, screen 35 overlapping the upper edge of screen y 36, said screens being spaced apart in a vertical direction as hereinafter specified.

Each of the side panels 46 is provided near each end thereof with outwardly extending brackets 52 which rest 'upon Vand are supported by the upper ends of vertical springs 54, the lower ends of these springs resting on seats 55 secured to the side members 12. The side panels 46 are also provided near their upper edges and at a point intermediate their length with a pair of outwardly extending brackets 56 to which are secured a` tures.

Frame 60 is also provided with outwardly extending brackets 65 to which bearing blocks 67 are secured, the latter being rotatably journalled on the eccentric portion 28 of transverse shaft 27 in much the same manner as bearing blocks 57 are secured on transverse shaft 19. Frame 60 is also supported on springs 68 much in the same manner as frame 49 is supported on springs 54.

The upper transverse members 64 serve as bases for vertical supports 69, the latter extending upwardly towards the undersides of screens 35 and 36 and carry at their upper ends the ejectors 37 and 38. The latter are composed of a plurality of parallel spaced bars 72 arranged so that one of said bars lies below a corresponding row of apertures 41 formed in said screens. The upper surfaces 73 of said bars are spaced downwardly from the underside of screens 35 and 36, a distance substantially that of the largest size of particle desired to pass through the screens in a manner as described hereinafter by example.

Secured to the lower transverse member 63 is the screen 39, the latter being comprised of a plurality of longitudinally disposed bars 75 extending in side by side relationship the full length of the apparatus and spa-ced apart a distance substantially equal to the smallest size of particle it is desired to retain as in a manner hereinafter described.

The apparatus is also provided with means such as chutes or aprons, not shown, arranged to receive the discharge of material from the lower ends of screen 36, ejector 38 and screen 39, in a manner known to those skilled in the art of the use of the apparatus of this nature in order that the material so segregated may be carried to separate bins or piles.

The arrangement of the parts of apparatus 1t) and their .relationship in relative size and spacing may be best described with reference to its use in screening an agglomerate material such as crushed gravel so as to segregate therefrom gravel particles of a uniform shape and passing 11/2 but not passing 3A inch. To produce material of this nature, the apertures 41 of screens 35 and 36 would be 11/2 inches in diameter if round and approximately 11/2 if square. The web portion of plate 40 lying between each row of apertures would be approximately 2 inches in width, the ejector bars 72 which would be approximately 1% inches in width, would lie spaced beneath the underside of plate 40 11/2 inches therefrom, and the triangular ribs 44 would lie approximately 11/2 inches away from the outside corners of said ejector bar 72. The screen 39 would lie below the ejector bars at least 3 inches and the bars 75 thereof would be spaced slightly vless than inch apart. The shafts 19 and 27 would be rotatably disposed relative to each other so that their eccentric central portions 21 and 28, respectively, would lie 180 apart, whereby upon said shafts rotatingthe screens 35 and 36 and ejectors 37 and 38 and screen 39 would vibrate in opposition.

It will be seen that material deposited upon the upper side of screen 35 will, by reason by vibration of the latter, tend to move downwardly over the latters inclined surface, the smaller particles of uniform shape up to 1%. inches passing downwardly through the apertures 41 and thence downwardly between the ejector bar 72. A particle of washed gravel which has taken the form of shards, that is, in which one dimension thereof is greatly elongated, will tend to pass endwise downwardly through the aper- However, before the shards having an elongated length greater than 11/2 inches can pass fully downwardly through the aperture, it will contact the ejector bar 72 v,lying therebelow, the vibratory movement of the latter 'cking the shards upwardly through the aperture so that ontinuevits flow over screens 35 and 36. The the` ejector bar 72 on shards is clearly illustrated `),R`E4 in which isri'ndicated shards 80 attempting downwardly between the apertures 41 of the -i In this figure, it will be seen that if a shard should become jammed in an aperture, the heavy construction of the bar 72, plate 40 and ribs 44, provides a means whereby the shards may be broken into pieces small enough to pass downwardly between the ejector bars to screen 39.

The material falling downwardly on screen 39 will therefore contain regularly shaped particles having a maximum passing size of 11/2 inches, together with shards whose elongated length is 11/2 inches or less. If the latter shards have a breadth and width of less than 3A inch, they will tend to pass downwardly through the bars 72 along with the rejected fines. The material, therefore, retained by screen 39 will be particles of uniform shape ranging between 11/2 inches passing and 3A inch retained.

In the operation of vibratory screens, it is often found that particles become jammed in the apertures of the screen elements, thus reducingv the efficiency of the apparatus. In order to reduce the tendency of the various screens in the present apparatus from becoming jammed, the bars 75 of screen 39 have a gradually reducing taper from their upper to their lower ends, as indicated in FIGURE 1 of the drawings. The taper is very slight, tapering from their upper ends to their lower ends so that the width of the spaces therebetween increases from 3% inch at said upper end to approximately 7s of an inch at the lower end.

It will be appreciated that due to relatively wide transverse spacing of the apertures 41, a considerable portion of the material to be removed will pass unscreened over screen 35, however, this portion of the material will fall on that portion of screen 36 in line with a row of apertures 41. All the material passing over both screens will therefore, at one time or another, pass over or through an aperture.

What I claim as my invention is:

1. A screening apparatus for separating, from an agglomerate mass of material having a percentage of shards, particles having a uniform size and shape comprising an inclined vibratory screen arranged to receive the material at its upper end, said screen having particle passing apertures of uniform dimension, ejector means having a plurality of spaced particle engaging surfaces arranged below the screen so that each of said surfaces lies vertically adjacent to a corresponding aperture below said screen and in a plane parallel thereto a distance substantially equal to the aperture dimension to thereby prevent the passage through the apertures of shards having one dimension substantially greater than the aperture dimension, said particle engaging surfaces being spaced apart to permit the passage downwardly of particles passing through the first screen, means to move the ejector means in a direction normal to the plane of the screen to thereby eject said shards upwardly out of said apertures, and a second inclined vibratory screen arranged below the ejector means to receive material passed by the first-mentioned vibratory screen, said second screen having apertures of smaller dimension taken transversely to the direction of flow of material than said apertures of the first-mentioned screen.

2. A screening apparatus for separating, from an agglomerate mass of material having a percentage of shards, particles having a uniform size and shape comprising a first screen comprising an inclined vibratory plate arranged to receive the material at its upper end, said plate having a plurality of apertures of uniform dimension arranged in rows extending longitudinally of the direction of flow of the material, ejector means having a plurality of particle engaging surfaces arranged below the screen so that each of said surfaces lies vertically adjacent to a corresponding aperture below said screen and in a plane parallel thereto a distance substantially equal to the aperture dimension to thereby prevent the passage through the apertures of shards Ihaving one dimension substantially greater than the aperture dimension, said particle engaging surfaces being spaced apart to permit the passage downwardly of particles passing through the first screen, means to move the ejector means in a direction normal to the plane of the screen to thereby eject said shards upwardly out of Said apertures, and a second inclined vibratory screen arranged below the ejector means to receive material passed by the first-mentioned vibratory screen, said second screen having apertures of smaller dimension taken transversely to the direction of flow of material than said apertures of the first-mentioned screen.

3. A screening apparatus for separating, from an agglomerate mass of material having a percentage of shards, particles having a uniform size and shape comprising a rst screen comprising an inclined vibratory plate arranged to receive the material at its upper end, said plate having a plurality of apertures of uniform dimension arranged in rows extending longitudinally of the direction of How of the material, ejector means comprising a plurality of longitudinally extending bars in spaced side by side relationship so that each bar lies vertically below a row of apertures in the screen a distance substantially equal to the aperture dimension to thereby prevent the passage through t-he apertures of shards having one dimension substantially greater than the aperture dimension, said bars being spaced apart to permit the passage downwardly of particles passing through the rst screen, means to vibrate the ejector me-ans in a direction normal to the plane of the screen to thereby eject said shards upwardly lout of said apertures, and a second inclined vibratory screen arranged `below the ejector means to receive anaterial passed by the first-mentioned screen, said second screen having apertures of la smaller dimention taken transversely to the direction of flow of material than said apertures of the rst-mentioned screen.

4. A screening apparatus as claimed in claim 3 in which each of the ejector bars is inclined parallel to said rst screen and tapers in width from its upper end to its lower end.

5. A screening apparatus for separating, from an ag glomerate mass of material having a percentage of shards, particles having a uniform size and shape comprising an inclined vibratory screen arranged to receive the material at its upper end, said screen having particle passing apertures of uniform dimension, ejector means having a plurality of spaced particle engaging surfaces arrange-d below the screen so that each of said surfaces lies vertically adjacent to a corresponding aperture below said screen and in a plane parallel thereto a distance substantially equal to the aperture dimension to thereby prevent the passage through the apertures of shards having one dimension substantially greater than the Iaperture dimension, said particle engaging surfaces being spaced apart to permit the passage downwardly of particles passing through the first screen, and a second inclined vibratory screen 'arranged below the ejector to receive material passed by the first-mentioned vibratory screen, said second screen comprising a series of longitudinally extending bars spaced apart in side by side relationship a distance less than the aperture dimension of the rst-mentioned screen.

6. A screening apparatus as claimed in cl-aim 5 in which each of the bars of the second vibratory screen tapers in width from its upper inclined end to its lower inclined end.

7. A screening apparatus for separating, from an agglomerate mass of material having a percentage of shards, particles having a uniform size and shape comprising a first screen comprising an inclined vibratory plate arranged to receive the material at its upper end, said plate having a plurality of apertures of uniform dimension arranged in rows extending longitudinally of the direction of ow of the material, ejector means comprising a plurality of longitudinally extending bars in spaced side by side relationship so that each bar lies vertically below the row of apertures in the screen a distance substantially equal to the aperture dimension to thereby prevent the passage through the apertures of shards having one dimension substantially greater than the aperture dimension, said bars being spaced apart to permit the passage downwardly of particles passing through t-he rst screen, and a second inclined vibratory screen arranged below the ejector to receive material passed by the first-mentioned vibratory screen, said second screen comprising a series of longitudinally extending bars spaced apart in side by side relationship a distance less than the aperture dimension of the first-mentioned screen.

8. A screening apparatus as claimed in claim 7 in which each of the bars of the ejector is inclined parallel to said rst screen and tapers in width from its upper end to its lower end and in which each of the bars of the second vibratory screen tapers in width from its upper inclined end to its lower inclined end.

9. A screening apparatus for separating, from an agglomerate mass of material having a percentage of shards, particles having a uniform size and shape comprising a first vibratory screen comprising a pair of inclined vibratory plates arranged in tandem and descending in overlapping order, said plates having a plurality of apertures of uniform dimension arranged in rows extending longi- .tudinally of the -direction of flow of the material thereover, a pair of ejectors, each comprising a plurality of longitudinally extending bars in spaced side by side relationship, each of said bars being spaced vertically below a row of apertures in the plate above and in a plane parallel to the plane of the screen a distance substantially equal to the aperture dimension to thereby prevent the passage through the apertures of shards having one dimension substantially greater than the aperture dimension, said bars being spaced apart to permit the passage downwardly of particles passing through the rst screen, means to move the ejectors in a direction normal to the plane of the screen to thereby eject said s-hards upwardly out of said apertures, and a second inclined vibratory screen arranged below the ejector to receive material passed by the first-mentioned screen, said second screen being comprised of a series of longitudinally extending bars spaced apart in `side by side relationship a distance less than the aperture dimension of said first-mentioned screen.

10. A screening apparatus as claimed in claim 9 in which each of the rows 0f lapertures in one of the plates of the first-mentioned screen lies `on the projection lof a line bisecting a pair of rows of apertures in the other of said plates.

11. A screening apparatus as claimed in claim 10 in which each of the -bars of the ejector and said second screen tapers in width from its upper inclined end to its lower inclined end.

References Cited by the Examiner UNITED STATES PATENTS 424,002 3/ 1890 Jones 209-384 HARRY B. THORNTON, Primary Examiner. L. H. EATHERTON, Assistant Examiner.

Claims (1)

1. A SCREENING APPARATUS FOR SEPARATING, FROM AN AGGLOMERATE MASS OF MATERIAL HAVING A PERCENTAGE OF SHARDS, PARTICLES HAVING A UNIFROM SIZE AND SHAPE COMPRISING AN INCLUDING VIBRATORY SCREEN ARRANGED TO RECEIVE THE MATERIAL AT ITS UPPER END, SAID SCREEN HAVING PARTICLE PASSING APERTURES OF UNIFROM DIMENSION, EJECTOR MEANS HAVING A PLURALITY OF SPACED PARTICLE ENGAGING SURFACES ARRANGED BELOW THE SCREEN SO THAT EACH OF SAID SURFACES LIES VERTICALLY ADJACENT TO A CORRESPONDING APERTURE BELOW SAID SCREEN AND IN A PLANE PARALLEL THERETO A DISTANCE SUBSTANTIALLY EQUAL TO THE APERTURE DIMENSION TO THEREBY PREVENT PASSAGE THROUGH THE APERTURES OF SHARDS HAVING ONE DIMENSION, SUBSTANTIALLY GREATER THAN THE APERTURE DIMENSION, SAID PARTICLE ENGAGING SURFACES BEING SPACED APART TO PERMIT THE PASSAGE DOWNWARDLY TO PARTICLES PASSING THROUGH THE FIRST SCREEN, MEANS TO MOVE THE EJECTOR MEANS IN A DIRECTION NORMAL TO THE PLANE OF THE SCREEN TO THEREBY EJECT

Images