US2358453A - Screening device - Google Patents

Description

P 5. J. GILSON 3 83 SCREENING DEVICE Filed Oct. 14, 1940 2 Sheets-Sheet l Patented Sept. 19, 1 944 UNITED STATES PATENT OFFICE s CREENING DEVICE Seth J. Gilson, Mercer, Pa., assignor to Heath Smith, Mercer, Pa.

ApplicationOctober 14, .1940, Serial No. 361,150

10 Claims. (01. 299-319) My invention relatesto a screening device for crushed stone, gravel, sIag sand and similar materials. It is particularly useful for testing samples of such materials, which it accomplishes in a highly efficient manner, the tests being speedy and extremely accurate as to the sizes and proportions of the constituent parts of the material tested, while the operations necessary to the tests are simple and easy to perform, and many operations heretofore necessary in prior testing devices are eliminated.

Inits more specific aspect my invention contemplates thev use of screening instrumentalities comprising a series of screen trays tightly bound together for operation as a'single rigid unit, which unit, preferably, is freely suspended vertically from the main stationary supporting frame, the suspension being preferably cushioned by supporting springsbetween the main frame andthe unit whereby vibration of the fixed. or supporting frame is minimized and substantially eliminated, the spring. connections .serving as shock absorbers. The unit is preferably centered top and bottom, conveniently by rods attached thereto, which also may constitutethemeans for binding its parts together, said rods advantageously extending through bushings in the top and bottom of the fixed frame to insure vertical reciprocation of the unit. In order to maintain the susv pension characteristic of the unit, the driving mechanism. for reciprocating it is preferably,

mountedon top of the fixed frame and connected to the unit by vertically suspended links, which:

are reciprocated by cams operated by said driving. mechanism. This location of the drive mechanism further permits the trays to occupy a lowerposition. Where they aremoreaccessibletothe.

operator. When the fixed frame is properly leveled, vertical operation is assured. By reason of the compactness and freedom from external vibration. of my structure, it is possible to operate the. screens-ata much i herspeed than similar devices of the prior art, and this higher speed enables me to employ a shorter amplitude of vibration of the unit. r

A. most. important aspect of. my invention is the construction-of. the oscillating unit whereby the screen trays. therein may be tightly bound together for the screening operation, yet by sim-- ple loosening of the binding mechanism any single tray may be independently removed and also anyone or more of the plurality of trays: may be left outflif the character of. thetests being made" do ,not, require theiruse. These; operations-may be simply accomplished by a system of spacers and accessory parts devised by me. Each tray compartment in' the unit is preferably tightly sealed on two sides and-the rearagainst escape of any material therefrom, while at the front an open space is provided for inspection of the operation as itproceeds. Each tray, when empty, isbalanced to Weigh the same as each other tray, balancing weights being applied, as necessary, to the individual trays to effect this. result. This permits a single reading of thescale to determine the weight of the contents of any giventray.

A further important feature of my invention is the location of the dust panin a fixed position below the reciprocating-frame; wherebyit re'-' mains stationary, whereas in priorconstructions it was mounted as partof the movable tray unit. All of the moving parts are contained within the outer or main frame, which is so constructed as to avoid contact by the operator with moving parts and therebythe highest degree -of safety to the operator is insured. Y

Further features and advantages of tion will hereinafter appear. c

The accompanying drawingsshow for purpose my invenof exemplification, but without limiting my in-' preferred embodiments spective view of a spacer member employed insaid unit; Fig. 3 is a front elevation partly insection showing features of my driving mechanism for oscillating said unit; Fig. 4; is a transverse vertical section onthe line 44 in Fig; 1; and Fig. 5 is a transverse vertical section of one of the trays. I v I Referringto thedr'awings, there is shown (Figs.

land 4) .a stationary framel having suspended for vertical reciprocation therein a rigid tray unit 2 and driving mechanism 3. for said unit.

The stationary frame I is preferably closed on its two sides and rear, while open at the front to permit access to the interior ofthe. casing and,

inspection of the trays. V

The reciprocating tray unit- 2 comprises an upper rectangular frame member 5' preferably made of, angle iron and a similar lower frame member 6, the latterbeing open at its front end, its free front ends being tied together by an inverted U-shaped tie member 1; located between the upper and lower frame members 5 and Bare aseries of U-shaped spacers 8 outwardly flanged at their upper and lower ends. Said upper and.

lower frame members and spacers are bound together to form the reciprocating unit by tightening rods 9 passing freely through openings H in the internal flanges H] at the top of the main casing and preferably through recesses or openings l2 midway the side flanges of the spacers 8, said rods being provided with screw threads at their lower ends on which are mounted nuts [3 rigidly attached as by welding to the underside of the lower frame member 6, said. rods being provided at their upper ends with stop collars l4 rigidly attached thereto as by welding, which are of a size sufficiently small to permit their being introduced with the rods through the opening H in the flange II), but sufiiciently large to prevent them passing through the opening in the upper frame member 5 through which the rods pass. In order to insure true vertical reciprocation of the reciprocating unit, a bearing member l5 (placed on said rods above the collars I4 before the latter are welded to the rods) are secured to the tops of the internal flanges In, over the openings II, and a similar bearing I6 is secured to the underside of the U-shalped lower frame member I! made of angles iron, which reinforces the bottom of themain stationary frame I. The bearing member 16 islof a size to fit the lower reduced ends H? of said rods. Said rods are provided at their top ends with means for turning the same in'theibearings, suchmeans being herein the unit, and one on each side near the front, their positions being more clearly indicated by the positions of the corresponding flange openings in the spacer flanges in Fig. 2. Any

variation in the number or location of these spacer rods, which will insure adequate support for the spacers, may, of course, be employed.

When the trays have been slid into their respective positions, with their flanges between the flanges of the spacers and top frame member, the crank members I9 are turned to raise the bottom frame member 6 upwardly and bind the flanges of the trays, spacers and upper frame member thereby relaxing the clamping action on each shown as crank extensions [9 formed on. the 1 upper ends of the rods. The reciprocating unit 2 is designed to carry a plurality of screen trays 20, each provided with. appropriate screen mesh bottom 2|. These trays are provided at their upper ends with outwardly extending flanges 22, saidtrays being of less depth than said spacers 8, and each tray being'adapted to be slid into the reciprocating unit 2, its flange 22 passing between the upper flange on a spacer and the lower flange of the spacer immediately above said first mentioned spacer. The flanges of the top tray are similarly adapted to lie between the horizontal flange of theupper frame member 5 and the upper flanges of the uppermost spacer member 8. A stationary dust pan 29a is suptray flange and permitting any individual tray to be'removed independently of any other tray.

The reciprocating unit 2 as a whole is resiliently mounted as a suspension member in the main frame by means of suspension rods 28, preferably located at each corner of the stationary frame and attached thereto' at their upper ends by heads 29, said rods passing through openings in the horizontal flanges of the upper frame member 5 and carrying two springs 39 and 3|, one located above said horizontal flanges and the other below them, the lower end of the lower spring resting upon a stop member 32 fastened to the bottom of said rods. The vertical flanges of the upper frame member 5 lie within the down-' turned fiange'33 ofthe stationary outer casing in order to protect the operator from the moving parts. Access to the rear suspension rod assemblies is effected through appropriate openings in the rear side of the maincasing;

The main frame is provided on its top with the top member 35, to which is attached an angular member 36, which supports the drive casing 31 attached therethrough through appropriate fasteners 38. As more clearly shown inFig. 3; the drive member comprises a driven shaft 39 suitably journaled in the. drive casing as shown, said shaft being provided at its opposite ends with eccentric or cam portions 40 on which are journaled' link members 4|, having bearings 42 at their lower ends adapted to have seated therein therod 43, which passes through openings in U-shaped ears ,44, one leg of each ear being secured as by welding to the upper frame member 5 of the vibrating unit 2. In assembling, the drive mechanism may readilybe connected to the tray unit 2 by inserting a pin or the like in the openings 45 in the main casing opposite the end of the rod 43, then driving said and frame' member 6. their lower'ends being provided with enlarged heads 26' rigidly fixedthereon as by welding and incapable of passing through said openings. These heads serve to limit the distance of the lower 'framernember 6 from the upper frame member .5. Also, permanently attached to thespacer rods '23 are stop members 2], each located a suflicient'distance below the corresponding upper flange. of a spacer member 9 :to prevent its spacer member dropping below it, said stops being larger than the corresponding openings in the flange of the spacer members. These stops are so located that each spacer member will be retained in position sufliciently below the spacer member above it to permit the flanges 22 of the trays tofreely'slide between them. As shown in the drawings, three such spacer rods are provided, one in the center 0f the rear of rod endwise in the direction of the far side until the link 4| can drop to its vertical position with its lower bearing in' line with the end of said rod then performing the same operation at the other side to permit lowering of the link 4| on that side, and finally centering said rod 43 by means of said pin until complete connections are effected between said link and said rod.

The edges of the screen member 2| of the tray 20 are preferably provided with a sheet metal binding with its outer edges turned in the form of ahook 46, as clearly shown in Fig. 5. Plate members 41 secured to the sides and ends of the tray'by bolts 48 and provided on their lower edges with hook members 49, to engage the hook members 46 onthe screen provide a convenient means of tensioning the screen, when needed, thus preventing sags and distortions of the screen members. The trays are balanced sov that.each lwillbe of ..the-sa'me,.weighti and .thisis convenientlyeeffected .bylQuse ,OifShiniS 2-50. of '.se-- '1 lected'weight locatediunder-Qthe. nutsTBL-onsaich bolts, 1-,

In .the ,operationof the device, the lcrankimembers VI 9 -,are2..operated rto. rotate.,the,,, rods. 9.; in the. nuts l3 fixed. to.the.lower.. frame. .Biuntil the: spacers 8 ..drop. on.their respective stops..21;.leav.-'- ing spaces, between adjacent. spacers; and ,the tops.

member- 5.. to ,permit. insertion ofzthe .traysj20,;1 10' their, flanges slidingover .the top flanges. of;- the. I spacers. into. the positions shown inJFig- 1.. Thereupon,' theirods. 9. are turned'by' the. crank member's. l9 the. oppositerdirection. tocliftl the;

lower,member;6.;until.al1 ofthe spacer..memberss andftrays.areprigidlyllocked tog'etherr Materiallc. having. beenfed, into. the. top, of; the. machine,-

the d iving,mechanism. is. .-then.set.inioperation which. operation maygbeu observed. through. the-1 openfrontofthe' main casing. When thelscre'ene. g

action of the spacers, any sinsletray. maybe; 1

individually removed independently of any other tray, and also the vibrating unit may be operated with as many trays as may be desired. The springs and 3| cushion the vibration and the bearings I3 and I5 at the top and bottom of the main casing maintain the rods 9 in vertical position, thus insuring a balanced system, a minimum of vibration being imparted to the outer frame.

While I have specifically described certain preferred forms of my invention, it is obvious that it iscapable of embodiment in various forms and modifications, and many features of my inven-' tion may be used without the conjoint use of other features, as conditions may indicate to be top of said main frame for vertical reciprocatory movement, means located at the top of said. main frame for vertically reciprocating said unit, said unit comprising upper and lower frame members, screen trays and tray spacer members alternately therebetween, and means for moving:

said upper and lower members toward each other to clamp said trays and tray'spacer members between them to form a rigid unit, or away from each other to release said trays and spacers from said clamping engagement to permit removal of one or more of said trays, said means for moving said upper and lower frames toward and I away from each other having vertical reciprocator y engagement with said stationary frame to compel vertical reciprocation of said unit.

2. A screening device comprising a main frame portion, a screen unit mounted for vertical reciprocatory movement in said main portion, said unit comprising upper and lower frame members, screen trays and tray spacer members, each provided with flanges, between said upper and lower frame members, the flanges on said trays lying between adjacent flanges of said spacer members, a binding rod passing through said upper and lower frame members and provided 7 above said upper frame member with a fixed stop preventing upward movement thereon of said upper frame member; and provided in the region of said lower frame member with screw threads carrying a stop nut in engagement with the. bottom side. of. said. lower frame, said. rod Y beings-rotatable in opposite. directions to cause said nut .to bind together or loosen, respectively, the members. of. said unit, the ends of. said rod' projecting through bearings at the upper and. lower; ends. of said main frame tov permit the unit to reciprocate. in vertical. direction, only.

' 3,; A screeningdevice comprising a main frame portion, .a screen unit mounted for vertical reciprocatory movement in said main portion, said unit comprising. upper and lower frame members,.screen trays and tray spacer members, each provided with flanges, between said. upper and lowerfran e members, the flanges on said trays lying; between adjacent flanges of said spacer. members,v and a binding rod passing through said-upperand lower. frame members and pro.-.

vided, above, said upper. frame member with 'a fixed stop preventin upward movement thereon of said upper framemember, and provided. in

the region of said lower frame member with.

screw threads carrying a stop nut in engagement wit eing rotatable in opposite directions to e ide ?e sv of a i t.

comprising upper and lower frame members, screen trays and tray spacer members, each provided with flanges, between said upper and lower frame members, the flanges on said trays lying between adjacent flanges of said spacer members, and rods attached at one end to said upper frame member and passing freely through openings in the flanges of said spacers and said lower frame member said rods being provided with adjustable means engaging aid lower frame member, which in one position binds said trays and spacers together and in another position releases said binding effect to permit individual removal of said trays and fixed stops on said rods,.each located sufiiciently below th flange of its correhaving upper and lower frame members, alternate screen trays and tray spacer members between said frame members, and means for binding said parts rigidly together or for releasing them, rods attached at one end to said upper frame member, and stops fixed at points on said rods to hold said spacer members sufliciently apart when released to permit withdrawal of any individual tray or trays.

6. A screening device comprising a screen unit having alternate screen tray and tray spacer members, means operable to bind said members together as a rigid unit, or to release them, and means to hold said spacer members sufficiently apart when released to permit withdrawal of any individual tray or trays.

7. A screening device comprising a screen unit having alternate screen trays'and tray spacers, said spacers being substantially U-shaped in horizontal cross-section and provided with flanges at their top and bottom edges, said trays being provided with flanges at their top edges, normally adapted to lie between flanges of adjacent spacers, and means for clampin said tray and spacers together whereby a dust proof seal is provided between said unit and the exterior thereof on two sides and the rear.

h the bottom side of said lower frame, said s id 1 1. 1 .9.. d o her or l se s ew screeni dev ce. p is n a screen unit,

8. A screening device comprising 'a screen unit having alternate screen trays and'tray spacers,

said spacers being substantially U-shaped in horizontal cross-section, and means for clamping said trays and spacers together whereby a dust proof seal is provided between said unit and the exterior thereof on two sides, and the rear.

9. A screening device comprising a screen unit havin alternate screen trays and tray spacers of greater vertical height than said trays, said spacers being substantially U-shaped in horizontal cross-section and provided with flanges at their top and bottom edges, said trays being provided with flanges at their top edges, normally adapted to lie between flanges of adjacent spacers, and means for clampingsaid trays and spacers together whereby a dust proof seal is provided between said unit andthe exterior thereof on two sides and the rear,- and inspection openings are provided over the tops of said trays, at

the front.

and lower frame. members, the flanges on said trays-lying between adjacent flanges of said spacer members, a binding rod passing through said upper and lower frame members and provided above said upper frame member with a fixed stop preventing upward movement thereon of saidupper'frame membenand provided in the region ofsaid lower frame member with screw threads carrying a stop nut in engagement with the bottom side of said lower frame, said rod being rotatable in opposite directions to cause said nut to bind together or loosen, respectively, the members of said unit, the ends of said rod projecting through bearings at the upper and lower ends of said main frame to permit the unit to reciprocate in vertical direction, only and other rods attached at one end to said upper frame memberand passing freely through opening in the flanges of said spacers and said lower'frame member and fixed stops on said last mentioned rods, each located sufficiently below the flange of,its corresponding spacer to hold the same sufliciently far from its adjacent spacer to permit the tray whose flange lies therebetween to be readily slid'out of the unit. j

SETH J. GILSON.

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