US2204920A - Flour sifter - Google Patents

Description

June 18, t1940. v TQBAiLY i 2,204,920

FLouRA slm-En Original Filed Dec. 3, 1936 2 Sheets-Sheet 1 if 5 7 1a ATTO R N EYS Patented June 18, 1940 Ulil'i STATS FLOUR SIFTER Theodore Bailey, Habana, Cuba Reled for abandoned application Serial No. 114,061, December, 3, 1936. This application September 6, 1939, Serial No. 293,635

7 Claims.

This invention is directed to an'improvement in sifters designed particularly for use in sifting flour and the like and constructed to permit selected and continued resifting.

'I'his is a re-le of my abandoned application 114,061 iiled Dec. 3, 1936.

The primary object of the present invention is the provision of a sifter in which the screen elements are mounted for rotary reciprocation for sifting purposes to thereby avoid the use of the conventional agitator and the wear on the screen elements incident to the use of such agitator.

A further object of the invention is the provision of means whereby the body of flour to be sifted is more or less divided to prevent undue accumulation of the material in a particular area of the screen elements under the centrifugal force on the material incident to the rotation of the screen elements.

A further object of the invention is the provision of means whereby the contents of the'sifter may be delivered beyond the sifter in predetermined measured quantities at will and wherein the sifter body is appropriately marked in order to enable the user to have a knowledge of the quantity of the material delivered to the sifter for sifting.

A further object of the invention is the pro- Vision of means designedy to bemanually controlled and serving to rotarily reciprocate the screen elements in a manner to permit selected rapidity in such operation as'may be desired;

A further object of the invention is the provision of duplicate spaced screens so that in each screening operation the material is subjected to a double screening action.

A further object of the invention is! the provision of means for mounting the sifter to hold the same rigidly in use while' siftingV and to provide for its convenient reversal when resiftin is desired or necessary.

The invention is illustrated in the accompanying drawings, in which v Figure l is a vertical sectional View through the sifter, showing the improved construction,

Fig. 2 is a vertical sectional vview showing the mounting of the sifter with respect to a fixed support, i

Fig. 3 is a front elevation of the support element, v

Fig. 4 is a broken sectional View showing the connection of the sifter to the support element,

Fig. 5 is a horizontal section taken above the sifter elements and through the operating means, the screens being omitted,

Fig. 6 is an enlarged vertical sectional View, partly in elevation, showing the screen carrying frame and the means for operating the same,

Fig. 7 is a sectional view` taken immediately above the cut-oit plate of Fig. l, and showing the plate in closed position,

Fig. 8 is an enlarged elevation of the sifter operating element, and

Fig. 9 is a Vertical sectional view, partly in elevation, showing the use of a closure element in place of the measuring receptacle.

The `sifter comprises a main body I, of cylindrical form and open at the respective ends.

This body is centrally formed with an annular enlargement 2 which, for a denite vertical length, provides a portion of relatively increased diameter to receive the peripheral portion of thel screen frame. As the sifter body I is otherwise of uniform diameter, this central enlargement provides for the reception of the screen-carrying frame and thus permits the screens proper to have a diameter equaling and in effect slightly exceeding the normal diameter of the body.

In substantial alignment with the upper and lower margins of the enlargement 2, the body is provided with transverse suporting strips 3 which thus extend transversely of the body in spaced relation. Arranged between the strips 3 is the screen frame including an annular metallic strip 4, brace strips 5 at the upper and lower margins `of the annular strip 4 andra central annular strip 6 connected to the brace strips and arranged concentric with the strip 4 and of materially less diameter than that of the strip 4. The screen frame is provided with upper and lower spaced screen sections 1 and 8. The screen sections 1 and 8 are of conventional metallic screen cloth of any desired mesh, provided at theA margins with reinforcing bands 9 and seated in offset annular channels IU at the respective marginal edges of the section 4.

'Ihe screen section as thus constructed comprises inner and outer circular strips with the screen cloth sections secured to the end margins of the outer strip and overlying and in Contact more or less with the ends of the inner strip 6, so that the screen cloth sections are spaced apart a distance equal to the axial length of the outer strip, which length is slightly less than the axial distance between the supporting strips 3 in the body i. The diameter of the outer strip 4 of the screen section approaches the diameter of the enlarged central portion 2 of the body, so that CIK the screen cloth sections proper are equal to or slightly exceed the internal diameter of the body I beyond the central enlargement 2, in order that the sifting function of the screen cloth sections will be at least commensurate with the full diameter of the interior body I.

The screen section is arranged between the supporting strips 3 and an element of a screen actuator is provided to rotatably support the screen section with respect to the strips 3. This particular actuating element is arranged between the screen cloth sections I and 8 and includes a member having spaced upper and lower lengths II and I2 formed at one end to provide a connecting yoke I3 and extended laterally at the opposite ends to provide pintles I4.

The actuating member is preferably formed of a single length of strip-like material and the pintles Ill, which are thus of angular form, extend through correspondingly shaped openings I 5 at the crossing areas of the braces 5 of the screen section, that is at the center of said section. As the pintles I@ are rectangular and the openings I5 of corresponding shape, any movement of the actuator described .vill compel a corresponding movement of the screen section.

The pintles IIS beyond the screen section are passed through circular openings I6 in the supporting strips 3 in order to permit unrestricted rotative movement of the pintles relative to the strips 3. Spacing disks I'I space the cross-bars 5 from contact with the strips 3 and cotter pins I8 pass through the pintles I4 beyond the strips 3 to maintain the relation ol the parts.

The actuating member described is arranged entirely within the strip 5 of the screen section and a link I9 pivotally connected to the yoke I3 is in turn pivotally connected to a bar ZIJ which extends through the screen section strips I5 and 4 to a point beyond the body I for connection to an operating member to be described. A reciprocating movement of the bar 20 will, of course, compel rotary reciprocation of the screen scetion and thus of the screens 'I and 8, the relation of the parts being such that in this movement the screens travel for a distance approximately degrees in each reciprocal movement. In order to provide for the necessary lateral movement of the bar 20 during this operation, the strips 4 and 6 of the screen section are formed with elongated slots 2I to permit necessary play of the bar.

Beyond the body I is arranged a hand grip 22, the ends of which are secured to the body at appropriate points in both directions beyond the enlargements 2. This hand grip 22 is preferably hollow, opening toward the body I, and centrally of such grip in line with the enlargement 2 there is provided a hollow guide bar 23 secured at its outer end to and within the hollow hand grip 22 and at its inner end 24 to the body I. The body in line with the hollow guide bar is formed with an appropriate opening through which the operating bar 20 extends and through the outer i free end of which bar 2l) is arranged a pin 25 slidable in slots 2B in the opposite faces of the hollow guide bar.

Pivotally connected to the hand grip Z2 are pressure members 27. These members are also of hollow form, connected at their inner ends to the respective end projections of the pin 25 and pivotally connected at their outer ends at 28 to the hand grip. These pressure members are slotter at the ends engaging the pin 25 in order to accommodate appropriate movements of the parts, and a spring member 29 housed within the hand grip 22 has its ends extended within and bearing against the pressure members, as indicated at 30 in Fig. l, to compel movement of said members in one direction. The pressure menibers are preferably corrugated, as at 3|, to alford convenient finger grips and prevent injury through sharp metal during operation.

The respective ends of the body I are normally provided with closures or caps 32 which have a removable connection with the ends of the body, either a threaded connection or a slot-and-pin connection as indicated at 33. Handies 312 er.- tend outwardly from the caps for providing for convenient hand support of the sifter as a whole as well as for convenient removal of the caps when desired or necessary.

'Ihe body I beyond the enlargement Il in both directions is preferably formed with annular oilset portions 35 whch thus afford interiorly of the body well dened markings which may indicate, and if desired are appropriately numbered to indicate, cup measurements, so that the user may accurately determine the quantity of material originally placed in the body for sifting.

As so far constructed, it will be apparent that with one hand gripping the hand grip 22 and the ngers of that hand engaging the pressure inembers 21, the latter may be moved on their pivots 28 and against the tension of the spring ends 3U 1- toward the hand grip to compel movement of the actuating member within the screen section and thus rotate the screen section and thereby the screens through approximately a quarter revolution, which screen section is operated in the il.

reverse direction on release of the pull on thc pressure sections 2'I through the medium of the spring terminals 3U. The screen section is thus reciprocated in a rotary manner as rapidly as desired, causing any material which has been delivered at one end of the body to be rapidly sifted through both screens to the opposite end of the body.

During this operation of the screen section,

there might be a tendency to pile up the material at the outer edge of the screen section incident to centrifugal force developed in the screen section movement and to avoid this force effecting the greater portion of the body of material.

the screen section strip 5 has been provided through which, as a matter of fact, the greater portion of the material will be passed during the sifting operation. This strip 6 of the screen section, therefore, prevents a piling up of any considerable portion of the material at the edges of y the screen section incident to centrifugal force.

In sifting flour, for example, particularly for use in baking, other materials are mixed in with the flour during the sifting and ordinarily one of the real purposes of the sifting is to insure an intimate mixture of these added materials with the flour. It not infrequently happens that a proper admixture of these additional materials or even an adequate sifting of the flour is not obtained in a single sifting operation and inthe conventional sifter, the material following one sifting is delivered into a bowl or other container and then if resifting is desired, which is nearly always the case, the material in the bowl is rcturned to the sifter and again sifted.

With the use of the present sifter, this resifting operation is obtained by merely reversing the position of the body I, that is, after the material has been sifted to one end of the body, the body is merely reversed, so that the end to which the III) material has been sifted becomes the upper end andthe operation above ldescribed is repeated and a second sifting and mix-ing of the material obl tained. This, of course, may be'repeated as many times as desired without other manipulation than merely reversing the sifter body. After the sifting and mixing operation has been completed, the cap '32 at the lower end may be removed and the contents discharged into an appropriate receptacle or such cap may be removed prior to-the nal sifting and the contents as sifted delivered directly into the body as siited.

While the reversal of the body and the holding of the same during the sifting operation may be conveniently accomplished through either of the handles 34, it may be advisable to provide means by which the sifter as a whole is more rigidly supported during the sifting operation. To pro- Vide -for this result, the sifter body may be provided wth an offset support 35 centrally provided with an outstanding pin .fit having ahead 31 spaced from the support. A bracket 3.8 designed to be secured to a xture has its upper portion 39 offset from the iixture and formed with a slot lil opening through the upper end and of a size to receive the body of the pin 36. Thus, the sitter body when connected with the bracket 33 is more or less rigidly supported for the sifting operation and yet conveniently removable and reversed for further cooperation with the bracket at will.

It is frequently desirable, and in fact nearly always necessary, for the housewife to measure the sifted material to insure the use of exactly the proper quantity for the contemplated product. Ordinarily for our such measurement is by cupfuls, and while it is true that the desired number of cupfuls may be introduced into the sifter at the start, it is nevertheless a known fact that there is a difference in volume between a cupful of unsifted our and a cupful of sifted flour, a

' cupful of sifted our making more than a cupful such accuracy without any effort or labor on the part of the user.

For this purpose, one of the caps, for example as indicated at di in Fig. l, may be formed with a central opening and a depending edge flange l2 defining the margin of that opening. The edge flange is slotted for a portion of its length and a cut-off plate 43 is arranged to move back and forth in the slot to a position to cover and uncover the opening in the cap. The plate d3 is pivoted on a pin. 44 carried by the cap beyond the iiange 42 and such plate is extended at d5 opposite the pivot and formed with a nger opening 46 in such extension to permit the plate to be swung to an open or closed position in an obvious manner.

The nange d2 may be interiorly threaded to receive the upper end of a container 41 which is of a size to receive just one cup of sifted our, al-

though of course any other volume may be provided ior, as desired. The container 41, when fitted to the ilange 42, is of course conveniently removable and its extreme upper edge immediately underlies the cut-off plate d3, so that after sifting or in the nal sifting, with the cut-on plate in open position, the container 41 will be lled and when the cut-off plate is returned to closed position, it will divide the material in the container from that remaining in the sifter body,

so that the container accurately measures just the quantity for which it is designed.

A closure cap section lisis designed to close the outlet in the cap di by cooperation with the flange 42 when the container i1 is removed. Thus, the sitter maybe used for continued resifting to the number desired and the cap section 48 removed, the container l1 applied and the cut-oli plate 43 manipulated to iill the container.

The improved sitter is practically noiseless in operation, insures an accurate and efficient double sifting of the material in each position, permits continued resiiting of the material by simply reversal of the sifter body, and provides for accurate measurement of the when desired. The screens proper are operated to secure the sifting operation and the agitator used in conventional sifters to move over the screen is entirely eliminated and thus a very material wear on the screens incident to the use of such agitators is prevented. The screens may be rotated rapidly or slowly and incident to the screening action, as well as to the agitation incident to the movement of the screens, there is a more eiective mixing of added materials throughout the mass of flour than ordinarily possible with the usual agitator and single screen.

In mounting the sifter from a iixed support, as provided for herein, it is desirable that the sitter be held against twisting or turning while 1n connection with the support. For this purpose, the element 38 connected to the sitter may be provided on its outer face with a longitudinally ranging slot 39 and the upright portion 39 of the support be of a width to seat in that slot. Thus, when in position, the sifter is capable of upwardmovement only with respect to the supporting element.

Of course, the parts may be constructed of any appropriate material and are preferably as light as consistent with the service demanded and it will also be understood that the receptacle 41, if desired, may be marked with various subdivisions of the full capacity of the container, so that a proportional amount may be delivered into the container, if desired. This division of the container is indicated though no particular stress is siited material laid thereon as it is conventional in measuring containers. v

Having thus described the present invention, what it is desired tov secure by Letters Patent is:

1. A sifter including a body open at the respective ends, caps closing the ends, a screen section supported transverse the body at approximately mid-length the latter, said screen section being mounted for rotary reciprocation within the body and including spaced screens, an edge strip supporting the screens, and an intermediate strip between the screens, said intermediate strip being concentric with and approximately midway between the periphery and centers of the screens, and means mounted exteriorly of the body for actuating the screen section.

2. A sifter including a cylindrical body formed with a central section of relatively increased diameter, a screen section mounted transverse the body and having its edge portion extended into said enlargement, said screen section including an edge strip, a central strip, and screens secured to the upper and lower edges of the edge strip and overlying the respective end edges of the central strip, the central strip being arranged between the screens concentric with and approximately midway between the periphery and centers of the screens, and mechanically operated means carried by the body and extending to and l connected to the screen section for compelling rotary reciprocation of said section.

3. A construction as defined in claim 2, wherein the body is reversible to permit successive screen operations through mere reversal of the body.

4. A construction as defined in claim 2, wherein the operating means for the screen section includes a hand grip secured to the body, pressure elements carried by the hand grip and movable relative to said grip, an actuating member connected to the screen section, and a connection between the actuating member and pressure members.

5. A construction as dened in claim 2, wherein the ends of the body are closed by removable caps, with one of the caps formed with an outlet, a cut-off controlling the outlet, and a measuring vessel to be removably secured to the outlet at will.

6. A sifter including a cylindrical body formed with an annular enlargement at approximately its mid-length, a cylindrical screen section supported transverse the body, with the edges of said section operating in the enlargement, said screen section including an outer imperforate strip, spaced screens proper secured at the respective end edges of the strip, an intermediate imperforate strip arranged between and contacting the screens proper, concentric with and approximately midway between the periphery and centers of the screens, and means carried by and manually operative exteriorly of the body to impart a rotary reciprocation to the screen within the body through approximately 90 degrees.

7. A sifter including a body, spaced screens supported within the body at approximately the central portion thereof, and an intermediate strip concentric with the body and arranged between and approximately midway between the periphery and centers of the spaced screens, operating means arranged within the intermediate strip and mounted for rotary movement, said operating means being connected to the spaced screens, a handle portion for the body, finger levers mounted in the handle portion for movement in both directions, and a connection between said levers and said operating means to cause the movement of the levers to compel rotary reciproation of the spaced screens.

THEODORE BAILEY.

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