US1913303A - Endless traveling water screen - Google Patents

Description

June 6,1933. 1.. G. BLEYER ENDLESS TRAVELING WATER SCREEN Filed April 23,- 1930 I5 Sheets-Sheet 2 INVENTOR Lloyd GZBZqyer; BY Z? ATTORNEY June 6, 1933. L. G. BLEYER ENDLESS TRAVELING WATER SCREEN Filed April 23 1930 3 Sheets-Sheet 3 wmmmwm" INVENTOR Lloyd Giflleyer;

ATTORNEYS v Patented June 6, 1933 a QI P tM IL WIAUKEE, Wiscons n, A conroiurio v 015 Wisconsin DLE TRAYELINGWATERSCREEN' Application filed April 23,

This invention relates to endlesstraveling waterscreens andhas for one of its objects to provide an automatic take-updevice for screens of this character which will constant- 1 1y take out the slack in the, screen chains and maintain the same taut. I i I i i a In order thatthe precise nature of the inventionmay be better understood it is said that in water screens of the endless type in which there is provided spacedliead and foot sprockets aboutwhich are trained the endless chains which carry .the'screen baskets there is a constant tendency towards slackness in the said chains. This is due not only to the stretching and Wear which commonly occurs inall chains, but also to the fact that because of the relatively great pitch of the chains, in some instances asmuch as two feet, and the consequent employment of sprockets havinga relatively few number of teeth, there is a constantlateral movement of the backor down runs of thechainwhich, if not compensatedvfor, tends to PIOdLlCGziLltGIIlZltG slack and taut conditions. i i 4:26 a In water screens of this type it is common to provide in the boot-at the footof the screen, trash seals which are formed through the cooperation ofitheiside plates ofthe moving screen baskets with: curved stationary plates in the boot, and since the clearances between those running, sealsis of necessity small, in order toprevent trash ,irom finding its-way through such seals, it is essential that the chains be maintained taut at all times in order tofprevent contact and undue wear of these, seal parts. a a a i Due to theprovision of these, trash seals in the boot and also due to the fact that the boot is commonly located considerably below the water level and between masonry side walls where it is relatively inaccessible, it is not practicaltomakethe foot sprocket adjustable for the purpose of taking up lslackin the chains as "has been heretofore proposed in connection with certain types of endless, vertical conveyors. I Theseconditions which exist in water screen practice,:therefore makeit practically essential that any takeaip mechanismoperate upon the head isprocketlof the screen or at; least that it be located above the 1930. Serial No. 446,597.

water level and awayfromthe foot sprocket inorder that the trash seals-inthe boot may be maintained. a 5

It is the primary object ofrthe presentinvention therefore, to provide an automatic '5 take-upldevice for traveling water screens which-operates to constantly and yieldably tend to move the head sprocket away from the foot sprocket in order that the chains may, at all times, be properly tensionedand that'the-trash seals in the boot be properly maintained in operative condition. i

\Vith the above andotheiuobjects iin' view which Will appear as the description proceeds, theinvention consists in the novel details of construction and combinations of parts more fullyhereinafter disclosed and particur larly pointed out in the appended claims: Referring to the accompanyingdrawings forming apart of this specification in which like reference characters designate like parts in Lll.tl18VleWSZ-- r i 1. a: M u, A Figure 1 is a sideielevational viewl partly broken away of arwell knownform of endless traveling water screen withthe presentiinvem tionapplied thereto; 7 a v a Figure 2 is an enlarged front elevational view of the upper portion of the screen frame shown in Figure 1, showing the parts constituting-the present invention applied thereto; 1 Figure? is a top plan view of theaparts shown in Figure fly a 1; Figure l is a sectional elevationalnview taken approximately on the plane indicated by the line 44 of Figure 2, looking in the direction of the arrows; a 1 Figure 5 is a fragmentaryfront elevational View, similarito FigureQ, ofa slightly modified form of the invention; a. a

Figure 6 is a sectional plan View of the parts shown in, Figure 5 taken approximately on the plane indicated by the line 6+6 of the said figure; and i m: 7 n i Figure 7 's a vertical sectional view taken approximately on the plane indicated bythe line,77 of Figure 5. p i v I a i Referring more particularly to Figures .1 to 4, inclusive, indicates the main vertical frame memberslof the water screen which usually take thei form of Z-bars, and which 100 are usually received in suitable guides set into the masonry walls 11 of the water conduit or flume. At the bottom of said members there is provided a boot 12 in which the foot sprockets 13 are journalled and the said boot is. provided with the stationary trash seal elements 14 and 15 which coact with the side plates 16 of the screen baskets in the well known manner,to prevent the passage oftrash around the screen atthe points where the baskets pass through the boot. Aswill be readily understood by those skilled in the art the said screen baskets are carried by screen chains 17 which are trained around the foot sprockets 13 as well as about the head sprockets 18, which latter are j ournalled in suitable bearings 19as will be clear from Figure 1. The said bearings 19 are slidably mounted between the-upright frame members 20, which constitute extensions of the main frame members 10, and guides 21, whereby the said head sprockets are free to slide vertically in order to maintain the chains in taut condition.

Aswas above mentioned the pitch of chains 17in. apparatus of this character is relatively great and it is common to employ sprockets of relatively few teeth, usually five or six in number, five being shown in the present drawings. It will be obvious from an inspectionof Figure 1 that with the parts in the positions. shown, as the head sprocket 18 moves in a counterclockwise direction from theposition illustrated, through an arc of approximately 36 the articulating center 22 ofthe chain will not only move downwardly but will move outwardly toward the left to approximately. a point 23. The same outward movement of the back runof the screen will takeplace at the foot sprocket 13 so that the entire back run will have been moved laterallytoward the left from the positions shown iniFigure 1.

There is also thesame tendency of movement in the front-or. up-runof the screen, but: this is prevented by the guide'or seal members 24 which are ordinarily provided inscreens of this type to prevent the passage of trash around the ends ofthe screen baskets. Ittherefore results that since lateral movement of the front run is prevented while lateral. movement of the back run is not prevented, the distance between the two runs is alternately greater'and less as the screen is m0ving,.which' in effect, is the same as shortening and. lengthening the chain, and unless provision is made to take care of this movement it is necessary that the chains be initially placedson thesprockets in a slack condition sosthatsthelsaid lateral movement may be accommodated. However, when: the chains are thus slackened the trash seals in the boot 12;.between the end. plates 16 ofthe screen basketsand the seal members-14 and 15 are permitted. to contact with consequentheavy wear upon the parts which necessitate frequent replacement of these seal elements.

In order to overcome these difficulties the bearings 19 are provided with upright rods or shafts 25, the upper ends of which are threaded as at 26 and carry nuts 27 by means of which the head sprocket 18 may be properly positioned initially as will presently appear. Transverse levers 28 and 29 are pivoted respectively at 30 and 31 in ears or brackets 32 carried by upright members 33 which are mounted upon the transverse frame member or beam 34. The outer ends 35 and 36-of the levers 28 and 29 are bifurcated and straddle the upright rods or shafts 25 as clearly shown in Figures 2 and 3, beneath the nuts 27. The inner ends of the levers 28 and 29 overlap as clearly shown in the said figures and the said inner ends have hung upon them as between straps 37, a suitable weight 38; The said weight 38 is always tending to lower the inner overlapping ends of the levers 28 and 29 and to therefore raise the outer bifurcated ends 35 and 36 of these said levers, which force is transmitted through the nuts 27 to the rods 25 and the slidable bearings 19 with the result that the head sprockets 18 are constantly urged upwardly thereby automatically taking up any slack in the screen chains 17. The force applied however is yieldable so that when the back run of the chains moves outwardly from the positions shown in Figure 1, as above described, the head sprockets 18 may move downwardly to accommodate the apparent shortening of the chains. The head sprockets constantly rise and fall during the operation ofthe screenandthe chains 17 will at all times be maintained in a taut condition, whereby contactbetween the seal elements 14, 15 and 16' in the boot will be prevented with a'consequent elimination of wear upon these said-elements.

A slightlymodified form of the invention is illustrated in Figures 5, 6 and 7 in which a separate weight is applied to each side of the screen instead of a single weight as in the preceding form. In this said modified form the levers 28 and 29 are shortened somewhat and are connected-through links 40, 41, and 42 to levers 43 which carry individual weights 44 which serve the same purpose as the weight 38 of v the preceding form; In each form it will be understood that the head sprockets 18 are initially positioned through adjustments of the nuts 27 upon the threaded ends 26 of the rods 25 after which the weights such as 38 and 44'will automatically take care of the tension upon the screen chains. In both forms of the invention shown slight inequalities in the tension of the separate chains will be automatically taken care of as will be readily understood.

It is obvious that those skilled in the art may vary the details of construction as well as the precise arrangement of parts without departing from the spirit of the invention,

and it is not wished to be limited to the above disclosure except as may be required by the claims. What is claimed is:

1. In an endless traveling water screen having a frame, a sprocket-carrying head shaft freely slidably mounted in said frame, a boot, a sprocket-carrying foot shaft in fixed rela- 0 tion to said boot, screw-threaded means for initially adjusting said head shaft relative to said foot shaft, and a long pitch screenbasket carrying chain trained about said sprockets, there being running trash seals between fixed portions of said boot and portions of the screen baskets, the combination of levers fulcrumed to said frame, one arm of said levers engaging said screw-threaded means; and a weight operatively connected to the other arms of said levers, for exerting a constant lifting force upon said head shaft to maintain said chains taut and prevent contact and wear between the trash seal parts in the boot.

2. In an endless traveling water screen, a frame; a boot; a sprocket-carrying head shaft slidably journalled on said frame for free movement toward and from said boot; long-pitch chains carrying screen baskets trained about the sprockets 011 said head shaft and passing through said boot; running trash seals between said baskets and boot; a pair of lovers pivoted to said frame and connected to the journals of said head shaft; and a single weight connected to both of said levers, wherebytthey constantly urge said shaft 1 away from said boot and prevent contact and wear between the trash seal parts.

In testimony whereof I aflixmy signature. LLOYD G. BLEYER,

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