US2537878A - Mechanism for supporting raising, and lowering the brushes of vibrating screens - Google Patents

Description

Jan. 9, 1951 E. L. COON 2,537,878

MECHANISM FOR SUPPORTING, RAISING, AND LOWERING THE BRUSHES 0F VIBRATING SCREENS 3 Sheets-Sheet 1 Filed Feb. 9, 1949 I NVE NTOR. MM 60012,

CYLJ Y/z/J K ATTORN Y 2,537,878 LOWERING NS 5 Sheets-Sheet 2 L. COON TING, RAISING, AND OF VIBRATING SCREE BRUSHES MECHANISM FOR SUPPQE THE ,a a 35% Q MGR Jan. 9, 1951 Filed Feb. 9, 1949 I INVENTOIR. Edna C0012, CL) I I M ATTORNEY l seaka xzam 55 8a I l I wa e: a

Jan. 9, 1951 E. L. COON 2,537,878

MECHANISM FOR SUPPORTING, RAISING, AND LOWERING THE BRUSHES OF VIBRATING SCREENS Filed Feb. 1949 3 Sheets-Sheet 3 2; Fig.4. 204710 1819 2 INVENTOR.

S 5 Ed zhLCoon,

BY W

ATTORNEY Patented Jan. 9, 1951 MECHANISM FOR SUPPORTING RAISING,

AND LOWERING THE BRUSHES OF VI- BRATING SCREENS Edwin L. Goon, Silver Creek, N. Y., assignor to S. Howes 00., Inc., SilverCreeln N. Y., a corporation of New York Application February 9, 1949, Serial No. 75,478

fiClaims.

This invention relates generally .to vibrating screens of the type whereinbrushes are arranged under and in contact with each screenunitand pare reciprocated rela'ively to the screenunit ;or

units in order at all times to :maintain themeshes open and clear, :therebytoavoid fblinding .at

any .one or more points -.and insure eificiency ,of the screening operation. Screensof this type, are

principally used in the-processing of .cereahgrains and other seeds, for example, oats, barley, buckwheat corn, wheat .and beam of various ,ln'nds, for the purpose of cleaning ortcleaning rand-grading.

The brushesare of the so called st1ip=l pe,

fl-1%. wherein the bristles are tmounted on :bars

or strips commensurate in length withlthe -s creens, the brushes being .reeiprocated in directions transverse to "the directions of reciprocation .of

the screen units. Each screen .unitvconsists .of a frame which carriesthe screening .elementand which includes end-:and intermediate cross ,bars, the frame being preferably-made in two or more adjoining panels. The bristles .are ,pmvidedin successive groups, spaced in adjacent relation in order to affiord clearances which {accommodate the cross bars. of the screening units, -thevbristles thereby being provided in fisections, .soato speak. Upward pressure is applied to the hairs of the brushes, thereby to maintain the contact of .the bristles with the screening-elements.

Two brushes in suitably spaced parallelrelation are connected for-movement as aiunit. Each brush uni-tisreciprocatory .upona ,pair of trans verse track :rods as supports, .these .being tarrangednear the ends f thevbrushes. The ,pres sure :to maintain the bristles in proper contact with the screening elements .is-exercised bythe ,trackrods upon theba-rs of the brushes.

In:tl'ieconstructions heretofore used. each. track rod is normally supported at .a fixed point relatively to pair of supporting brackets, these being mountedfor vertical adjustment upon parts of the stationary frame of the. screen. Whenthe bristles become worn .to an extent such that they are not properly.discharging theirJunction supportin rbraclrets for the two. correspond- ..ing track rods are shifted to a higher: elevation on the qiraine, thereby to renew the proper and uniform contact of. the lbristes with the screenin elements. When renewal of the brushes or substitution of the screeningvelementsisrequired it is necessary, in order that the un-its or screening elements maybe accessible, to move the track rods to suitably .lower positions .on their supporting brackets. .Afiler the. brushes ha-vebeen renewed or screening elements substituted the track rodscare restored to their original or working positions on their supporting brackets, and appropriate adjustment of the positions ofthe brackets onthe supporting frame is thereupon made in order toestablish proper and uni- :iorrn contact of the bristles with the screening elements.

From the foregoing itwill'be seen that inorder to maintain proper contact 'ofthe bristles with the screening elements periodic adjustments of the positions of four supporting brackets (for each brush unit) are required andthat in making such adjustments care must be exercised to insure an approximately uniform degree of pressure of the bristles uponsthescreening elements. It will be obvious that inthese adjustments, in order to avoidtoo frequent .intervalsfor the ne cessity of adjustment, the initial pressure contact of the bristles upon the screening elements wi l be in excessive degree and that no ideal norm of pressure contact can be achieved. It will also be seen that when renewals of the brushes or substitutions of the screening elements are required the track rods must bemoved to the appropriate lower positions on their supporting brackets and that when the work has been done the track rods must be restored to their initial positions on their supporting brackets and readjustments of the positions of the brackets upon their supporting frame bars must be made in order to establish proper and uniform initial contactof the bristles with the screening elements.

These o erations involve a substantial degree of time and labor. Moreover, the determination of the uniform contact of the bristles with the ereening elements and the proper degree of the initial uniform pressure of the bristes upon the screening element is, perforce, left to the judgment of the workmen, based on their skill and experience and rule of thumb assay.

If the pressure contact of the bristles with the screening elements as effected by the workmen is not approximately uniform, as ,is frequently the case, uneven Wear of the bristles results and renewals of the brushes are required. Due to this fact and aso due to the fact that no ideal norm of pressure contact can be achieved and maintained the necessity for the adjustment and renewal of the brushes, operations themselves intrinsically expensive, occurs at intervals so frequentas to impose a substantial and additional costly burden of labor and expense. Where, as in ,mostinstances, more than onebrush unit is required, these conditions are aggravated and the burden of expense is multiplied.

The invention relates specifically to improvements in the mechanism for the support of the brushes. The objects are to provide for a constantly maintained, approximately ideal, norm of uniform pressure contact of the bristles with the screening element, to provide for the continuous automatic compensation for wear of the brisles, and to provide for the quick, easy and labor saving lowering of the brushes when their repair or renewal is required and for their equally quick,

easy and labor saving restoration to normal working position, all without any labor, except the direct and easy manual movement of controlling parts, and without any exercise of judgment or skill on the part of the attendant other than his ability, by observation, to determine when the brushes are not properly discharging their function.

In the accompanying drawings an embodiment of the invention is illustrated in its operative association with sundry elements of the vibrating screen of which it forms a part.

Figure 1 is a side elevation, with parts broken away for clarity of illustration, of a vibrating screen in connection with which the invention is employed.

Figure 2 is a cross sectional view on the line 2-2 of Figure 1 looking in the direction of the arrows.

Figure 3 is a detail fragmentary cross sectional view, drawn to a somewhat enlarged scale, on the line 2-2 of Figure 1, looking in the direction of the arrows and showing one of the track rods in a normal or working position.

Figure 4 is a vew similar to Figure 3 on the line 4-4 of Figure 1 looking in the direction of the arrows.

Figure 5 is a detail perspective view of one of the several and similar manually moveable controlling parts.

Figure 6 is a detail perspective view of a plate for cooperation with the controlling part shown in Figure 5.

Figure 7 is a detail horizontal sectional View on the line 7-7 of Figure 4.

Figure 8 is a detail cross sectional view on the line 8-% of Figure 1.

In respects other than the features of the invention and sundry structural elements included in the subject of my co -pending application, Serial No. 75,477, Patent 2,510,741, the vibrating screen conforms to standard practice. It embodies a main frame, designated generally as l, which includes vertical side elements designated generally as 2, these being connected together by cross bars 3, conveniently of angle iron section. Each side element 2 includes horizontal bars :3, vertical end bars 5, intermediate vertical bracing bars 6 and a diagonal bracing bar 7 which extends between the lower horizontal bar 6 and the vertical end bar 5 at that end of the frame where the driving mechanism is mounted.

The screen includes the usual shoe, designated generally as S, which carries, in accordance with standard practice, the usual scalping element 9 upon which the grains or seeds to be processed are discharged from the usual hopper (not shown) and one or more screen units designated generally as i ii, two such units in superposed relation being shown in the drawings. The grains or seeds which pass through the scalping element 9, in accordance with standard practice, are discharged upon an inclined apron i i, whence they gravitate to a screen unit iii in coplanar relation to the apron.

In accordance with standard practice, the shoe is supported for reciprocation in the general direction of its length, for example, by vertical spring bars l 2 pendant from the upper cross bars 3 at each end of the frame I, the bars I2 being connected at their lower ends to appropriate transverse bars of the shoe. Any suitable mechanism l3 (motor driven by means unnecessary to show in the drawings) for effecting the reciprocation of the shoe 8 may be provided, the mechanism schematically shown conforming substantially to the construction shown in the patent to Both, No. 1,517,587 of December 2, 1924; (currently known in the industry as the Buhlei drive), and including a rotatable gyrating weight i5 mounted upon a shaft 56 journaled in supporting brackets ll secured to and projecting forward from parts of the shoe 8 at its front end.

As shown in the drawings, each screen unit 1!] conforms to standard practice and consists of a frame which carries the usual screen element I8. With vibrating screens of the usual length for the purposes described, it is preferable, and in accordance with standard practice, that the frame of the screen be composed of separate rectangular panels I9, severally consisting of side bars 25 and end bars 2| (and, optionally, intermediate cross bars 22). Two panels are shown in the drawings (Fig. 1), each of which carries a section of the screen element I8. The screen element sections, of course, are coplanar and in adjoining relation. The frame of the screen unit is supported by the shoe 8 and the side bars 20 of the adjoining panels are fitted in grooves or channels 23 which are provided by upper and lower spaced parallel bars 24 and 25 secured to the side walls of the shoe. The apron I l is carried by a rectangular frame 26, also supported in the channels 23 in adjoining relation to the panel 59 at the upper or higher end of the screen unit. Cross pieces 23a and 23b carried by the shoe at the ends of the channels 23 confine the panels l9 and the frame 26 in the channels 23. The upper cros piece 231) is removable in order to enable the removal from the channels 23 in successive relation of the frame 26 and the panels I9.

The openings or meshes of the screen elements are kept clean by brushes, designated generally as 21, which are of the so-called strip type. The arrangement and operation of the brushes conform to standard practice in that they are located under, and with their bristles in contact with, the screen elements; they extend longitudinally of the shoe and are substantially coextensive in length with the screen elements; and they are reciprocated at a relatively slow rate (compared to the rate of reciprocation of the shoe) transversely of the screen elements during the longitudinal vibration of the shoe. In accordance with standard practice, two parallel brushes are provided for each screen element and are connected for movement as a unit by a centrally located tie-rod 28 and end cross bars 29. The standard means for reciprocating the brushes is sufllciently indicated by the showing of its cables 30, pulleys 3| over which the cables are trained, and the drive pulley and associated gearing 14.

In the vibrating screen construction preferred, and in accordance with the invention which forms the subject of my copending application, Serial No. 75,477, the cross bars 29 are so mounted for sliding movement upon track rods 32 and the continuation of the clearances 52. of the clearances -52 is such to provide easy accommodation for bars 2l and 22. The depth track rods-in turn, are so mounted relatively to the shoe that the brushes move longitudinally :in unison with the .shoe, thereby have no longitudinalmovement relatively to the screen elemerits, and, during theirmovement longitudinally with the shoe, are reciprocated transversely of the screen elements as aforesaid. The track rods 32 project through slots 33 in the side walls of the shoe (Fig. 3) andthrough alining slots 34 in supporting plates35 attached to the outer faces of the side wall of the shoe. Thereby the track rods .32'participate in the movements of the shoe. In order that the brushes maymove in unison with the shoe the cross bars 29 are so mounted upon therods 32 that they will participate in the movement ofthe rods 32 with the shoe. For this purposethe cross bars 29 are preferably of angle iron cross section with their co-planar horizontal .fianges extending in relatively opposite directions from their vertical flanges.

ciently appears from the showing .of the cross bars, viewed comparatively, in Figures Band 4:,

. respectively.

The brushes 21, as shown and preferred, are

of the construction which forms the subject of my copending application, Serial .No.'75,4'77, the term brush comprehending both the bristle sec tions and their supporting means. The brushes 21 include a suitable number of structurally separate or unitary bristle carrying elements 15. Thesemay be of any construction which includes asuitable base or holder 46 for the bristles ii. The elements #35 are preferably of the general construction shown inthe patent to Peterson. No. 2,303,386 of December 1, 1942. The bristle carryingelements are lineally straight and may be provided by being cut in sections of suitable length from a continuous elongated strip. The base or holder is preferably of dove-tail cross sectional outline as clearly shown in Figures 3 and i.

The brushes '2'! also include anelongated supporting rmember 48 for theelements A5 and to which said elements are individually secured in suitably spaced relation. The-members 48 extendlongitudinally of the screen units and are suitably spaced inparallel relation. Each sup porting member 38 is preferabl of an le iron cross section and includesa horizontal flange 29 and a verticalflange 5B. The horizontal flanges 49 of each pair of associated members surest upon and are secured to the horizontal flanges of a pair of corresponding cross bars :29. The central tie rod 28 for a pair of corresponding brushes is connected to the vertical flanges 5?) of the associated members 58 and is utilized to carry the hooks 5i with which the ends of the cables 30 are engaged, the hooks 5! being provided at each end of the tierod and being at the outer .sides of the flanges so as shown inIFigures 3 and .4.

The spacing of the bristle carrying elements 45 provides between them clearancesdilior the accommodation of .the .bars 2! and .22 of the .screenpanel elements it. The .uerticalflanges 50 of the supporting member Adare recessed .to provide clearances 53 which .aline wit-hand form The width of the combined clearances 52-5iis such. in each instance, as towaccord with the permissible reduct-ion in the extent of the bristles, :due to wear.

In "other words, progressively with thewearnof the bristles, the springs 38 (arransed-asdater 75;

Thi relation sufli- I end of the plate 35.

shoe. .of downwardly extending cam projections 42, the

\ bru hes :describedain detail) will raise the brushes and the depthcof the combined clearances 52 -453 is such as to provide for this action.

The attachment of the elements .45 to the flanges 5J.is preferably eiiectedby a clamping action andit is for the purpose of such a clamp- .ing action that the base orholden it is-preierablgy of dove-tail. cross sectional outline. One member of the clamp is provided by the flange 458 which, .for this purpose, has its upper portions v5 (i. ue.. the.portions located between the clearances 53) inwardly inclined at an angle icon- .forming to the inclination of either side .wallof the base or holder 46. The other member .55 of the clamp'is of general ogee or Z-shaped :cross sectionxandconsists of a clamping flange 5.6.013- :posed :to a portion :54 01 the flange 50 and inwardly inclined in the opposite direction at an angle conforming to the inclination of either side wall of the base or holder 45, a horizontal base portion 51 upon which the base or holder 46 rests and a depending vertical attachment flange 58 which adjoins .and is removably secured to the flange 59 of the supporting member 48 as by bolt and nut fastenings 59. The members 55 are structurally separate from one another, are

attached as units tothe vertical flange 50, and are lineally .co-extensive with the portions of the .flange 58 between the clearances 53.

Inaccordance with the invention the end; parts of the track rods 32 which project beyond the side wallsof the shoe 8 carry dependingstems 38 which in each instance extend through an opening in a horizontal bracket 31 at the lower The plates 35 may .:be mounted upon any suitable part of the screen but, as above stated, are preferably'attached to the shoe, this mounting of the plates conforming to the use of the track rodsto move the screen units with the shoe as set forth in the preceding description. The stem serves to center a compression spring 38 which reacts against the bracket 31 and against a nut 39 adjustably mounted upon'the stem 35. The springs 38 nor- 7 mally cause the bristles of the brush to bear with suitable pressure against the screenelements l8 and in serving this function compensat for wear of the bristles. Convenient access to the brushes 2? 'for the purpose of repair or substitution is provided for by longitudinal cam bars at each side of the shoe 8 and which are slidably mounted in brackets 4! secured to the side walls of the Each cam "oar M is provided with a pair cam surfaces 53. of which extend from fiat or dwell surfaces 'The cam bars it are provided as companions in pairs for the several brush units andare formed at their outer ends with suitable hand grips the. In order to gainaccess to the the cor esponding cam bars op posite sides of the shoe 8 are pulled forward manually. In Figure l the cam bars are shown in their normal position. In Figure '2 the cam bars of the upper pair shown in their normal positions and the cam bars of the lower pairare .shown in their advanced positions.

ment of each cam bar in either direction islim- The move- When the companion cam bars of each pair "are "pulled forward the cam surfaces it ride upon theprojecting end portions of the trackrotlsBZ andeffiecit the downward movementpf the track rods within the slots 33 and 34. The forward movement of the cam bars is continued until the dwell surfaces 44 engage over and upon the track rods, thereby to maintain them in their lowered positions. When the track rods are lowered the pair of brushes of the brush unit which they support follow them and at the end of the forward movement of the cam bars occupy a correspondingly lowered position. Thereupon one or more of the screen element panels I9, as may be necessary, is removed in order that access may be had to the parts of the brushes which require repair. When the repair has been made the screen element panel or panels is replaced and the cam bars 48 are pushed back to their normal positions, the springs 33 at the same time restoring the brushes to their normal positions wherein the bristles bear with pressure against the screen elements E8.

The brackets M are of channel cross section, the vertical extent of their channels being sufiicient to permit the upward movement of the cam bars with the track rods 32 as the latter are raised by the springs 38 through the full range necessary in eifecting continuous automatic compensation for wear.

When the cam bars 4% are pulled forward to effect the lowering of the track rods 32, in order to provide for access to the brushes and the brush units, the projections 4-2, by means of their cam surfaces 43, initially ride upon the projecting portions of the rods 32 and raise the cam bars relatively to the brackets iii to the upper limit of the wear compensating movement of the track rods 32. When the cam bars reach such upper limit their further upward movement is prevented by steps 52 carried by the plates 35 near their upper ends, these stops being preferably in the form of anti-friction rollers. With their up- Ward movement so limited the forward pull of the cam bars is continued whereupon the cam surfaces 53 act positively to depress the track rods 32. When the track rods are fully depressed the dwell surfaces M of the cam projections 42 ride over the projecting ends of the track rods 32 and, with the cam bars bearing against the stop rollers 52, maintain the track rods in their fully depressed positions until such time as the repairs of the brushes have been completed whereupon the cam bars it are returned to their normal positions.

When the cam bars are returned to their normal positions the reverse action takes place, that is to say, when the dwell portions it have moved beyond the projecting ends of the rods 32 the rods are moved upward by the springs 38 to such limit as is established by the initial engagement of the bristles of the brushes with the screen elements, the cam bars in their further continued return movement moving downward relatively to the track rods until their cam surfaces have passed beyond the track rods at which time the lower horizontal surfaces of the cam bars engage the track rods and the cam bars are thereby supported by the track rods in positions wherein they are spaced from the stops E2, the clearances 63 (Figures 3 and 4) normally obtaining between the cam bars, and the stops being sufficient to provide for the upward movement of the cam bars with the track rods as the latter are raised by the springs 38 through the range necessary in effecting continuous automatic compensation for wear.

During the operation of the screen the cam bars move in unison with the shoe 8. For this purpose the cam bars have a close frictional fit against the faces of the plates 35 and the inner vertical faces of the associated brackets M, the frictional degree of this fit however not being such as to prevent the upward movements of the cam bars with the track rods (and relatively to the brackets a l) as effected by the wear compensating action of the springs 38 upon the projecting ends of the track rods 32.

The attendant in charge of the screen can determine, by observation, when the brushes are not efficiently serving their purpose. When this fact is determined the brush units are lowered by the simple and direct manual action of pulling the associated cam bars forward, an action which involves virtually no labor or expense and is accomplished in a matter of seconds. When the repair or renewal of the brush has been made the brush units are restored to their normal working positions by the equally simple and direct manual action of pushing the cam bars back into their normal positions, again an action which involves virtually no labor or expense and is accomplished in a matter of seconds. In connection with the restoration of the brush units to their normal working positions it will be noted that no manual setting of the brush units is required and that the initial pressure of the bristles upon the screen elements is determined and eiiected automatically, without dependence upon the judgement and skill of the attendants and without the liability of any lack of uniformity throughout the extent of the brush units of the initial pressure with which the bristles bear upon the screen elements. Ehis initial pressure conforms to an ideal norm and this norm is continuously maintained by the continuous automatic wear compensating action effected by the springs 38.

I claim:

1. In a vibratin screen of the type which includes a vibratory shoe, means for effecting longitudinal vibration of the shoe, a screen unit carried by and vibratory with the shoe and consisting of a frame and a screen element carried thereby, brushes of the strip type extending longitudinally of the screen unit and having bristles which bear with pressure against the under face of the screen element, the brushes being substantially co-extensive in length with the screen element, transverse track rods upon which the brushes are supported, and means for reciprocating the brushes upon the track rods transversely of the screen element during its longitudinal vibration with the shoe: mechanism in cooperation with the track rods for supporting, raising and lowering the brushes comprising springs adjacent the ends of the track rods and which act with pressure eiTect on the track rods to raise them in connection with the wear of the bristles, cam elements consisting of longitudinal bars mounted for manually effected longitudinal movement and supported upon the track rods, the bars having downwardly extending cam projections which in one direction of longitudinal movement of the bars engage the track rods and push them downward in opposition to the pressure of the springs and in the opposite direction of longitudinal movement of the bars disengage the track rods and permit them to be raised by the springs, and means against which the cam elements react consisting of stops above, and normally spaced from, the bars and which limit their upward movement during the engagement of the cam projections with the track rods whereby said projections become eifective to push the track rods downward.

2. Mechanism for supporting, raising and lowering the brushes of vibrating screens as set forth in claim 1 wherein the cam projections are provided with inclined cam surfaces and with straight dwell surfaces for engagement with the track rods, the dwell surfaces extending from the lower ends of the cam surfaces, the dwell surfaces, upon the completion of the movement of the bars to effect the lowering of the track rods, being operative to maintain the track rods in their lowered positions and being operative when the bars are moved in the opposite direction to disengage the track rods and permit them to be raised by the springs.

3. Mechanism for supporting, raising and lowering the brushes of vibrating screens as set forth in claim 1 wherein supporting plates are provided near each end of the track rods and have vertical slots through which the track rods extend, the plates being provided at their lower ends with brackets and at their upper ends carrying the stops, and wherein the projecting portions of the track rods are provided with depending stems which project through openings in the brackets and upon which the springs are mounted, the springs reacting against the brack ets and against parts carried by said stems.

4. Mechanism for supporting, raising and lowering the brushes of vibrating screens as set forth in claim 1 wherein the track rods participate in the vibratory movement of the shoe, and wherein brackets are carried by the shoe through which the longitudinal bars extend, the brackets confining the bars with a degree of frictional pressure such that the bars, when in their normal positions, participate in the vibratory movement of the shoe.

5. Mechanism for supporting, raising and lowering the brushes of vibrating screens as set forth in claim 1 wherein the track rods participate in the vibratory movement of the shoe, brackets are carried by the shoe through which the longitudinal bars extend, the brackets confining the longitudinal bars with a degree of frictional pressure such that the bars, when in their normal positions, participate in the vibratory movement of the shoe, and the longitudinal bars are pro vided with a pair of projecting lugs severally for engagement with one of the brackets as a stop and by which the manual movement of the longitudinal bars in either direction is limited.

6. Mechanism for supporting, raising and low ering the brushes of vibrating screens as set forth in claim 1 wherein the track rods participate in the vibratory movement of the shoe, supporting plates are provided near each end of the track rods and are mounted upon the shoe, the plates having vertical slots through which the track rods extend, being provided at their lower ends with brackets and at their upper ends carrying the stops, the projecting portions of the track rods being provided with depending stems which project through openings in the bracket and upon which the springs are mounted, the springs reacting against the brackets, and other brackets are carried by the shoe through which the longitudinal bars extend, the last named brackets confining the longitudinal bars with a degree of frictional pressure such that the bars, when in their normal positions, participate in the vibratory movement of the shoe.

EDWIN L. COON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 190,572 Fulton May 8, 1877 360,592 I-Iuxtable Apr. 5, 1887 525,301 Whitmore Aug. 28, 1894 695,842 Scott Mar. 18, 1992 797,499 Cornwall Aug. 15, 1905 1,097,887 Smith May 26, 1914 1,122,765 Kime D88. 29, 1914

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