US1984891A - Screen - Google Patents

Description

F. E. MHCK Er Al. 1,984,891' 4 SCREEN Dec. 18, 1934.

e Sheets-sheet 2 l Filed June 18, 1931 F. E. MIICK ET AL SCREEN 6 Sheets-Sheet 5 Filed June 18, 1931 I Dec..18, 1934. VF. E. MncK Er AL SCREEN Filed June 18, 1931 6 Sheets-Sheet 4 Inman 0715' I 'rederz'cZJzz'c/ Dec. 1s, 1934.,v

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l Dc. 18, 1934. l F. E. MHCK Er AL- 1,984,891

SCREEN Filed June 18, 1931 e shets-sheet 6 Patentedv Dec. 18,1934 l 1,934,891

UNITED STATES PATENT?oFFicEI f issuer SCREEN Frederick E. Muck, Philadelphie, and Frederick E. Munn-111km ruk, re., signers u Linkmit (sompany, Chicago, lll., a corporation of Application June 18,1931, serial No. 545,212 11 claims. (ci. 21o- 116) This invention relates to a screen, preferably the screen and its associated'mechanism..` The a bar screen, and to ameans and an apparatus framework may comprise vertical members B for cleaningthe screen. and inclined track members B1 which are joined It has for one object to provide a sectional -at their upper ends to a platform B2 which they 4screen construction. It has for another object. support and upon which the driving mechanism -5 to provide an apparatus for cleaning a screen in of the screen assembly is mounted. Suitable which the screen is subjected to a minimum of cross frame members B1I may be used. Addition-v wear. Another object is to provide a rake for al inclined frame members B4 lie generally parcleaning the screen cleaning means. Another allel with the Vinclined track members -Bl and 1U object is to provide, 'in connection with the hoistwith them extend into the space A1. A plate B5 10 ingor moving apparatus for hoisting the screen, extends between the upper ends of the lmembers an automatic means for controlling the position B4 and may be fastened to them. Thisv plate is of the rake. largely situated outside of the space A1 and does Other objects will appear from time to time not come in contact with the material flowing in the specication and claims. f therethrough. The frame members B1 and B4 1.5 The invention is illustrated more or less diamay be joined by apron-like side members B6.

grammatically in the accompanying drawings, Attaching brackets Brl B7 are positioned on the `whereinzoutside of the track members B1 B1 and are Figure 1 is a vertical cross section, showing adapted to rest upon and to be fastened to suit- 1'50 the screen in position, the screen being shown able supports to assist in positioning the screen- 20 largelyin side elevation, with parts broken away ing assembly. Upon, the` cross frame members and parts in section; f B3 may bel positioned a-refuse chute B8 over Figure 2 is a vertical cross section on line which the refuse from the screening assembly 2-2 of Figure 1, showing the screen in 4rear is discharged. Any means may be used for re- 25 elevation; moving the refuse from the chute. A plate or 25 Figure 3 is a planview showing the screen in skirt B9 may depend ,from Vthe upper edge of position, with rake and carriage omitted; the plate B5 and overlap one side of the 4chute Figure 4 vis a transverse cross section,`taken B11 as indicated in Figure 1. on an enlarged scale at line` 4-4 of Figure 1; The screen proper may be made ysectionally,

30 Figure 5 is a detailed'vertical sectional view, the screen being formed of bars C which are 30 showing -the mounting of the foot of the screen;y preferably tapered at their rear edges as at C1 l Figure 6 is a transverse vertical sectional de` and fastened by welding or otherwise to a plutail on an enlarged scale, showing one end of rality of cross members C1. At their upper endsthe carriage and rake assembly; they may be additionally tapered as at C3 to 35 Figure 7 is a vertical section taken at line match the downwardly inclined flange or end 35 7-7 of Figure 6, looking in' the direction of C4 of the plate B5.

the arrow; Y A carriage'which supports a rake, is mounted Figure 8 is a side elevation of the slack cable to move up andv down the screen. It moves switch, with parts broken away; along the tracks B1 and carries a rake and a rake l0 Figurev 9 is a "section along the vline 9-9 of cleaning mechanism. The rake assembly in- 40 Figure 8. A cludes two or more' carriage members D each of Like parts are designated 'by like characters which has projecting inwardly from it a lug D1 throughout the specification and drawings. in which is seated a set screw D2 which may have A indicates generally a wall construction deco-operating with it a locking nut D3. A shaft 4J fining a liquid chamber A1 which has suitable D4 is journaled in the carriage members D and 45 cutlets and inlets and into and through which -from the shaft the rake mechanism is suspended. liquid to be screened is moved. A plate A2 The rake proper includes a pair of side memmay be secured to the bottom wall or floor members E, each of which is provided with a hub E1 bei A, as indicated particularly in Figuresl from which projects a lug E2. A stiffening mem- 00 and 5- The plate may be fastened t0 the oor ber E3 extends from the hub E1 and along a por- 50 member in any suitable manner and is provided tion of the side arm or member E. Fastenedto with `one or moreA upwardly projecting pins A3 the hub .E1 is `arpair of ,lever armsl E4, E5. Ex-

Which vare adapted to receive and position the tending laterally across between the two side lower end of .the screen. armsE and fastened to them preferably at their A suitable' framework is provided to support lower edges, is an arcuate plate E6 which may in either direction.

have at oneside an upwardly extending flange or edge E1. Removably positioned at the opposite edge of the plate E6 is a finger bar E8 which has xed or formed upon it fingers E9 which are so shaped and positioned as to extend between the bars C when they are moved into a position to do so, as shown for example in Figure 4.

Supported on the shaft D4 is a wiper assembly. This includes a plurality of side or end members F each of which is provided with a hub F1 and a lever arm F2 which is perforated for a bearing support as at F3. A bearing pin F4 is received in the perforation F3. The hubs F1 are mounted for rotation about the shaft D4. A latching cam F5 is positioned and fixed upon the shaft D4. This cam is notched as at F6. A latching lever F7 which is provided with a hub portion Fa about which a spring F12 is positioned, is supported upon the pin F4. The member F7 at its outer end carries a latching nose F9 and at its opposite end has a relatively inclined and preferably somewhat shorter lever arm portion F10. Extending laterally across between the side members F of the Wiper assembly is a wiping plate F11 which may have at its upper edge a ange F12. F13 is a spring serving normally to hold the latch in engagement.

The driving and controlling mechanism is preferably mounted on the platform B2. It includes a motor G upon which a solenoid brak'e G1 may be positioned. The motor, through a flexible coupling G2 and a speed reducer G2, drives a pinion G1 which is in mesh with a gear G5 on the shaft G6, which is supported in suitable bearings. A traveling cam limit switch Gl is mounted adjacent the gear G5 and is provided with a shaft which carries a pinion Ga which meshes with the gear G5 and is driven by it. Thus motion of the gear is effective upon the limit switch to control the motor.

Keyed or otherwise fastened to the shaft G6 is a pair of drums H, H1. Adjacent these and loosely mounted on the shaft G6 is a pair of drums H2, H2. Brakes H4 and H1? are positioned to engage, respectively, the drums H2 and H3. Each of the pairs of drums H, VH2 and H1, H3 are provided on the adjoining faces of their hubs, with overlapping portions which permit some relative movement of' the drums and serveV to engage them and cause them to move as one, after a certain amount of rotation of the shaft Thus, for example, the drums H, H2 will have relative movement at rst, when the shaft is moved in either direction, and will thereafter move in unison.

A From each of the drums H, H1 a hoisting cable or rope I extends downwardly and is fastened to one of the .levers E4 of the rake assembly. From each of the drums H2, H3 a lowering cable or rope I1 lextends downwardly and is fastened to one of the arms Es'of the rake assembly.

Extending downwardly from the platforrnB2 are one or more supports J, upon each of which may be movably mounted a roller support J1 carryinga roller J2. This roller is positioned in the path of the rake assembly so that as the latter moves along the track, the roller may contact the wiper arm- F2 and thev latcharm F10.`

Pivotally mounted beneath the frame B2 is a slack cable switch lassembly of which one or more may be used. Each assembly includes'a shaft K, supported invbea'rng brackets K1 K1 and hav- 'ing fixed to it a pair of arms K2 K2 which are joined at their lower ends by a shaft K3 which a flanged sheave K1 llpOIl is mounted. The

sheave may rotate upon the shaft and may also move along it. It engages the rope or cable I. Fixed on the shaft K is a lever arm K5 which may have a counter-weight K6. Fixed ,also on the shaft K is a lever arm K7 which has a laterally bent portion K8 adapted to strike a switch operating rod K9 when moved to a suitable position and thus to contact the switch lever K1o of a switch K11.

It will be realized that whereas we have herewith shown and described a practical operative device, lnevertheless many changes might be made in the size, shape, number and disposition of parts, without departing from the spirit of our invention and we wish, therefore, that our showing be taken as in a sense diagrammatic.

We have used the word cable or rope as applied to the hoisting members I and I1. These, of course, could be changed to any suitable flexible means, and where the word rope or cable occurs in the specification and claims, it is to be understood as meaning any fiexible member which could be used in place of a rope or cable to raise or lower the rake.

The use andoperation of our invention are as follows:

The screen and itsassociated parts are positioned in the path of flowing liquid so that the liquid must pass through the screen. The bars intercept material and that which is larger than the spaces between the bars is caught by them and held from passing through. As will be seen particularly from the detail in Figure 4, the bars are thicker at their up-strearn edges than at their down-stream edges, being tapered toward the down-stream side. The bars are preferably straight sided for a distance before the taper is commenced. Such bars offer less friction to passing liquid and minimize the loss in head. By reason of this shape of the bars, solids of approximately the width of the spaces between the bars which are caught on or between them will be removed by the rake. The teeth of the rake, when the latter is in raking position, normally extend between the bars of the screen sufficiently to force solids which have lodged between the bars beyond the straight sided portions and to the tapered portions where the clearance is suicient to permit further movement of the solids through and away from the screen. By this tapered construction of the screen bars, clogging up of the spaces between the bars, in parts of the screen not actually reached by the cleaning fingers of the rake. is prevented. The bars are assembled into sections of convenient size so that a screen can ordinarily be installed by the use of one or more sections of bars and so that subsequent repair and renewal may be accomplished simply and wit-hout the necessity of always removing an entire section. In the particular form shown, each of the screen sections is provided at its lower edge with a plate having holes adapted to engage pins 'which are set into the floor of the channel through which liquid is to ow and the cross piece at the top, as indicated particularly in Figure 1, fits into or joins a structural member so as to support the .upper end of the screen bars preferably above the flow line.

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. poses of the present invention it is suilicient that means be provided for reversing the direction of movementcf the rake assembly and for preferably stopping the rake for aperiod at the lower limit of its excursion and for stopping it again at the upper'limit of its excursion. It is preferably stopped longer at the upper limit of its excursion than 'at the lower limit and at the upper limit a cleaning operation is effected, preferably automatic, to wipe or scrape the rake proper clean of material which has been removed from the bars. .and brought up -by it and which has adhered to within lugs D'l -which 'form a part of or are attached to the carriages.

Journaledupon the shaft D are a pair of side arms E which preferably carry hubs E from which project lugs E2 positioned opposite the lungs Dl of the carriages D. The relative position of the side arms and the carriages may be adjusted by varying the' position of the set screwsD2 in the lugs D, as these set screwsbear. against the lugs E2. tened at the lower end of the side arms E is a plate preferably arcuate in shape,.which carries removably attached to it a finger-bar havingfingers of such size and shape that they can penetrate. into the space between the screen bars. Double arm levers are fastened. to the hubs E1 andl by means of these arms, to which' cables are attached, the entire rake assembly may be raised and the rake proper may be rotated so as to swing the rake into and out of contact with the screen bars and plate.

y Hoisting cables I are preferably'lfastened to the levers E and lowering cables `I are fastened to -the lever ends E.

When the rake assembly is hoisted', its weight and the material on it is carried bythe hoisting cablesv I and vthe rake is rotated into the position shown in full lines in Figure 1. This rotating movement is made possible by a limited amount of slack which is allowed to develop in the lowering cable I 1. When the rake assembly is lowered, slack is allowed to develop in the hoisting cable I and for an interval the assembly is thus held by the lowering cables I and thus the rake rotates into/the position indicated in dotted lines adjacent the bottom of the screen in Figure l. This relative rotating of the rake parts occurs because the hoisting cablesare wound on drums H, H 1 which are xed von the driven shaftand because the lowering cables are wound on drums H 2, H, which, while mounted upon the same shaft and-adapted to be driven by it, are so arranged, by means-of drum hubs, that whenever the shaft reverses its direction of movement there is an interval in which the shaft rotates without rotating the drums H 'H s as they are held, respectively, against rotation by brakes H H 5 and it is only after a certain amount of -rotation of the driving shaft that the drums H2 and Ha commence to revolve with the other drums. Thus, .with the parts in the position indicated in dotted lines adjacent the lower end of Figure l, when the hoisting cables are drawn up, since the hoisting cables I are about the drums H, Hl which are keyed tothe shaft G', these cables. at once move and since the cables Il are about the drums H H which are for the moment free for movement with relation to the shaft, these cables I `are not drawn in and thusl at the start the only effect is upon the levers E" and the parts are .thus tilted into the position shown in full lines in Figure l. before any hoisting of the rake occurs. The drum hubs and brakes are so arranged that only the proper amount of rotating movement carr occur. Thereafter the drums H2 H"1 become locked to the other drums, and are -rotated andthe cables I are thereby drawn in at the same speed as the cables I.

. 'In the reverse movement, when the'screen asscmbly is to be lowered, the shaft Gi is rotated and the cables I, being wound about the drums H H1, which are fixed to the shaft, are at once paid out or unwound while the cables I1, which are wound aboutthe drums H2 H3, which for the moment are free for movement with relation to the shaft Gs andsareheldfby the brakes, are not initially paid -out or unwound and thus the lever ends E4 are lowered for a brief period before the levers E5 commence to move. lThereafter rotating movement-occurs which rotates the rake assembly back into the position which is shown in the dotted line position shown -at the lower end of Figure 1. Thus in hoisting, the rake is automatically brought into operative position in which the teeth of the fingerbar penetrate between-the bars of -the screen and in lowering the rake is automatically b rought into position inwhich the nger bar and thel rake as a 'whole are rotated outwardly away from the screen and it is in this positionv that the rake assembly is lowered.

Additional members. are provided in the rake assembly for cleaning or wiping the finger bar l and rake. These members move with the rake assembly and form a part of it, but are also mounted and arranged for relative movement with respect to the arcuate plate so that at the' proper time in the cycle of `operation of the assembly,'the wiper or scraper is automatically actuated to clean therake plate and the linger bar'. This wiper assembly includes a pair of arms F which are mounted for movement on the shaft D4. A latch cam is also mounted on the shaft and is keyed with respect to it. The arms F carry angularly disposed levers F2 upon which a latch F'I is pivoted. The latch part F9 bf the latch Fr1 normally engages a notch FG in the latch cam and so holds the wiper against movement vrelative to the shaft D4.` As the rake assembly is moved toward the upper limit of its excursion, the outer end of the latch lever F10 contacts a cam J2 and is depressed so that the.

latch is free to rotate out of engagement with the latch cam into the position shown in dotted lines att the upper end of Figure l. Thereafter the outer .end of the lever portion F2 of the wiper arms contacts the same cam J2 and as the CII Cil

a lever frame and engaging the hoisting cable.

The roller being in engagement with the hoisting cable, will be affected if the carriage assembly should meet an obstacle before it reaches its lowest predetermined position. If that should occur, excess slack would develop in the hoisting rope o1 cable and the lever frame formed of the members K2 K2 and the shafts K and K3, the latter carrying the sheave K4, would rotate in a counterclockwise direction,

. as shown in Figure 8, and the member K7 would contact the switch operating arm K9 andif moved sufiiciently would contact the switch lever K10 to operate it and stop further lowering.

It will be understood that the brakes Hl-and H5 are drag brakes' and that they preferably engage the drums lconstantly and are in contact with them at all times. Thus these brakes hold the loose drums from turning when they. are not actually being driven from the hubs of the xed drums.

turning, except when they are actually being driven positively from the drums which are xed on the shaft. The friction for this purpose can be very slight, so slight indeed that as a result of this friction practically no additional power is required to overcome the resistance.

We claim: v 1 l. In combination with a screen, a rake assembly, movably positioned with relation thereto, means for moving the rake assembly therealong, the rake assembly including al rake adapted to be tilted into and out of engagement with the screen and including also a cleaner mounted to move with said assembly and adapted to be moved back and forth across the rake to clean the same, and automatic means for tilting the rake out of engagement with the screen and for tilting it into engagement with the screen. v

2 In eombinationwith a screen, a rake assembly, movably positioned with relation thereto, means for moving lthe rake assembly therealong, the rake assembly adapted to be tilted into andl out of engagement with the screen, and including also Aa cleaner mounted to move with vsaid assembly and adapted to be moved back and forth across the rake to clean the same, and automatic-means for tilting the rake out of engagement with the screen and for tilting-it into engagement with the screen, and for operating the cleaner to clean the rakeA adjacent the upper limit of its excursion.

3. In combination with a screen, a rake assembly, mova'bly` positioned` with relation thereto, means for-moving the rake assembly ytherealong, the rake assembly including a rake adapted ,to be tiltedv in to and out-of engagement with the screen and including also Aa cleaner mounted to .move with said assembly and adapted to be moved back and forth across the rake to clean the same, and automatic The brakes are normally just 4tight enough to prevent the loose drums from including a rake means for tilting the rake out of engagement with the screen upon lowering, for tilting it into engagement with the' screen upon raising and for operating the cleaner to clean the rake adjacent the upper limitI of its excursion.

4'. In combination with a screen, means for cleaning the screen, including a rake assembly mounted to move along the screen, the assembly including a rake, the assembly also including a wiper mountedto move with theassembly and adapted to be moved to clean the rake, an automatic means for actuating the wiper, automatic .hoisting means for raising and lowering the rake along the screen, and automatic means for tilting the rake into and out of engagement with the screen, said means including a driven shaft, said shaft carrying a drum iixed` upon it and a drum loosely mounted upon it, the rake assembly carrying levers, a cable joining one lever to the fixed drum and a cable joining another lever to the loose drum, whereby when the shaft is rotated in either direction the cable joined to the fixed drum is 'at once moved, and whereby the cable joined to the loose drum is at first not moved.

5. In combination with a screen, means for cleaning the screen, including a vralre assembly mounted to move alongthe screen, the assembly including a rake, the assembly also including a wiper mounted lto move with the assembly and adapted to be moved to clean the rake, an automatic means for actuating the wiper, automatic hoisting means for raising and lowering the rake along the screen, and automatic means for tilting the rake into and out of engagement with ,the screen, said means including a driven shaft, said shaft carrying a drum xed upon it and a drum loosely mounted upon it for limited relative movement with respect to the xed drum in either direction about the shaft, the rake assembly carrying two levers, a cable joining one lever to the fixed drum and a cable joining the other lever to the loose drum, whereby when the shaft is rotated in either direction the cable-joined to the fixed drum is at once moved, and whereby the cable joined to the loose drum is at rst not moved.

6. In combination with a bar screen, means for cleaning the screen including a rake assembly mounted to move along the screen, the assembly including a rake and adapted in one position to engage the bars, the assembly also including a wiper mounted to move with the assembly and vadapted to be moved to clean the rake, an automatic means for actuating the wiper, automatic hoisting means for raising and lowering the rake along the screen, and automatic means for tilting the rake into and out of engagement with the screen, said means including a driven shaft, said shaft carrying a drum fixed upon it and a drum loosely mounted upon it for limited relative movement with respectto the fixed drum in either direction labout the shaft, the rake assembly carrying twojlevers, a .cable joining one lever to the fixed drum and a cableA joining the other lever to the movable drum, whereby when the shaft is rotatedin either direction thecable vjoined to the fixed drum is at once moved, and

whereby the cable joined to the loose drum is at first not moved, and is, after a predetermined movement of the xed drum, moved.

'7. In combination with a screen, a cleaner therefor, including a rake assembly. automatic means for raising and lowering the rake asseming a pair of carriages, a shaft in them, rake arms fixed upon the shaft and carrying at their outer ends a plate, a rake, the plate having a finger bar, and wiper arms journaled on the shaft, carrying at their outer ends a wiper adapted to wipe the rake.

8. In combination with a screen, a cleaner therefor# including a rake assembly, automatic means for raising and lowering the rake assembly, along the screen, the rake assembly including a vpair of carriages, a shaft in them, rake arms fixed upon the shaft and carrying at their outer ends an arcuate plate, a rake, the plate having a nger bar, and wiper arms journaled on the shaft, carrying at their outer ends a wiper adapted to wipe the rake, a latch mechanism adapted normally to hold the wiper armv against rotation about the shaft, and automatic means for freeing the wiper for movement.

-9. In combination with a screen, a cleaner therefor, including a rake assembly, automatic means for raising and lowering the rake assem.

bly along the screen, the rake assembly including a pair of carriages, a shaft in them, rake arms iixed upon the shaft and carrying at their outer ends an arcuate plate, a rake, the plate having a finger bar, and wiper arms journaled on the shaft, carrying at their outer ends a wiper adapted to wipe the rake, a latch mechanism adapted normally to hold the wiper arm against rotation about the shaft, and automatic means for freeing the wiper for movement and for moving it to wipe the rake adjacent the upper limit of its excursion.

10. In combination with a bar screen; a cleaner theref including a rake assembly, automatic means for raising and lowering the rake assembly along the screen, the rake assembly including a a pair of carriages, a shaft in them, rake arms fixed upon the shaft and carrying at their outer ends an arcuate plate, a rake, the plate having a nnger bar, and wiper arms journaled on the shaft, carrying at their outer ends a wiper adapted to wipe the rake, a latch mechanism adapted normally to hold the wiper a'rm against rotation about the' shaft and automatic means for tilting the rake into engagement with the screen bars, and automatic means for freeing the wiper for movement.

11. In combination with a b'ar screen, a cleaner therefor, including a rake assembly, automatic v means for raising and lowering the rake assembly along the screen, the rakel assembly including a pair of carriages, a shaft in them, rake arms rlxed upon theshaft and carrying at their outer ends an arcuate plate, a rake, the plate having a finger bar, and wiper arms journaled on the shaft carrying at their outer ends a wiper adapted to wipe the rake, a latch mechanism adapted normally to hold the wiper arm against rotation about the shaft and automatic means for tilting the rake into engagement with the screen bars as the rake moves upwardly, and for tilting it out of engagement with the screen bars as it'moves downwardly, and automatic means for freeing the wiper for movement.

FREDERICK E. MIICK. FREDERICK E. MAJOR.

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