Abstract
A flour sifting device (1), having a flour sifting tank provided with a flour sifting trough with flour sifting holes at the bottom, and a rotating brush located inside the flour sifting tank having a rotating shaft (7*) and devised to brush the flour sifting holes. The rotating brush hasa first plurality of discrete flexible brush elements (12c*) that are distributed on said rotating shaft (7*) and extend therefrom in a radial direction with respect to said rotating shaft (7*) such that collectively they form a screw conveyor with a circular outer contour. The brush elements (12c*) are arranged on a second plurality of separate identical brush modules (12*), each brush module (12*) including a number of said brush elements (12c*), preferably an equal number of said brush elements (12c*), and the brush modules (12*) are individually and removably mounted or mountable on the rotating shaft (7*).
Claims
1. A flour sifting device (1), comprising: a flour sifting tank (4) provided with a flour sifting trough (5) with flour sifting holes at a bottom of the flour sifting trough; a rotating brush (8) located inside the flour sifting tank (4) having a rotating shaft (7, 7*) and arranged to brush the flour sifting holes; the rotating brush (8) comprises a first plurality of discrete flexible brush elements (12c, 12c*) that are distributed on said rotating shaft (7, 7*) and extend therefrom in a radial direction with respect to said rotating shaft (7, 7*) such that collectively the first plurality of discrete flexible brush elements (12c, 12c*) form a screw conveyor with a circular outer contour; said brush elements (12c, 12c*) are arranged on a second plurality of separate identical brush modules (12, 12*), each said brush module (12, 12*) comprising a number of said brush elements (12c, 12c*), and the brush modules (12, 12*) are individually and removably mounted or mountable on the rotating shaft (7, 7*).
2. The flour sifting device (1) of claim 1, wherein the brush modules have an equal number of said brush elements (12c, 12c*).
3. The flour sifting device (1) of claim 1, wherein there is at least one of the brush elements (12c) per each said brush module (12), said brush element (12c) forming essentially a complete helical winding.
4. The flour sifting device (1) of claim 3, wherein said brush element (12c) comprises at least one radial notch and the separate brush modules (12) are arranged on the rotating shaft (7) such that respective ones of the notches of the brush modules (12) are aligned in a direction parallel to the rotating shaft (7).
5. The flour sifting device (1) of claim 4, further comprising a stirring bar (13) that extends parallel to the rotating shaft (7), said stirring bar (13) being held in the notches of the brush modules (12).
6. The flour sifting device (1) of claim 3, wherein the brush modules (12) further comprise a stirring element (12j) that is arranged on at least one side of the brush element (12c) and that extends in the radial direction.
7. The flour sifting device (1) of claim 6, wherein the stirring element (12j) extends essentially over a whole diameter of the brush module (12).
8. The flour sifting device (1) of claim 6, wherein the stirring element (12j) is formed integrally with the brush element (12c).
9. The flour sifting device (1) of claim 6, wherein one of the stirring elements (12j) is located on each side of the brush element (12c), and the stirring elements (12j) on both sides of the brush element (12c) are located at a common circumferential position.
10. The flour sifting device (1) of claim 9, wherein said stirring elements (12j) cover a pitch (P) of said brush element (12c) in an axial direction.
11. The flour sifting device (1) of claim 1, wherein there are a plurality of brush elements (12c*) per each said brush module (12*), and said brush elements (12c*) collectively forming at least one helical winding.
12. The flour sifting device (1) of claim 11, wherein there the plurality of brush elements (12c*) per each said brush module are arranged equally spaced in a circumferential direction.
13. The flour sifting device (1) of claim 11, wherein at least one of said brush elements (12c*) is oriented in counter-helically.
14. The flour sifting device (1) of claim 1, wherein the brush modules (12, 12*) are aligned on the rotating shaft (7, 7*) with respect to a circumferential position of the brush elements (12c, 12c*).
15. The flour sifting device (1) of claim 3, wherein the brush modules (12) further comprise a stirring element (12j) that is arranged on at least one side of the brush element (12c) and that extends in the radial direction, and the brush modules (12, 12*) are aligned on the rotating shaft (7, 7*) with respect to a circumferential position of the stirring elements (12j).
16. The flour sifting device (1) of claim 14, wherein the brush modules (12, 12*) comprise a central through-hole (12e, 12e*) for accommodating the rotating shaft (7, 7*), said through-hole (12e*) comprising an alignment notch (12m*) and said rotating shaft comprising a longitudinal protrusion (7d*) for engaging said alignment notch (12m*).
17. The flour sifting device (1) of claim 1, wherein said rotating shaft (7, 7*) has a square section.
18. The flour sifting device (1) of claim 1, wherein the rotating shaft (7) has one end with a stop (7a) for the brush modules (12) and one threaded end (7c) for threadedly securing said brush modules (12) on the rotating shaft (7).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] Further features and advantages of the present invention will become apparent from the following description of preferred embodiments with respect to the drawings.
[0046] FIG. 1 shows an embodiment of the flour sifting device in a sectional view;
[0047] FIG. 2 shows an embodiment of the rotating shaft in disassembled form;
[0048] FIG. 3 shows a first embodiment of the brush modules;
[0049] FIG. 4 shows an alternative view of the brush module in FIG. 3;
[0050] FIG. 5 shows an embodiment of the rotating brush and a stirring bar in disassembled form;
[0051] FIG. 6 shows the embodiment of FIG. 5 in assembled form;
[0052] FIG. 7 shows a second embodiment of the brush modules;
[0053] FIG. 8 shows an alternative view of the brush module in FIG. 7;
[0054] FIG. 9 shows a perspective view of several brush modules as in FIGS. 7 and 8 arranged on a rotating shaft;
[0055] FIG. 10 shows a different perspective view of several brush modules as in FIGS. 7 and 8 arranged on a rotating shaft;
[0056] FIG. 11 shows a different embodiment of several brush modules and a rotating shaft in disassembled form;
[0057] FIG. 12 shows the rotating shaft of FIG. 11 in assembled form;
[0058] FIG. 12A shows a variant of the rotating shaft of FIG. 11;
[0059] FIG. 13 shows a perspective view of one of the brush modules from FIG. 11;
[0060] FIG. 14 shows a different perspective view of the brush module in FIG. 13;
[0061] FIG. 15 shows a sectional view of the embodiment in FIG. 11 in its assembled form;
[0062] FIG. 16 shows a first perspective view of the embodiment of FIG. 15; and
[0063] FIG. 17 shows a second perspective view of the embodiment of FIG. 15.
DETAILED DESCRIPTION
[0064] In all of the Figures, the same reference signs are used to indicate same elements or at least elements having similar functions.
[0065] FIG. 1 provides an overview of the flour sifting device in accordance with the invention. Referring to FIG. 1, according to one embodiment, the flour sifting device 1 comprises a flour accommodating basin 2, the flour accommodating basin 2 having a first flour outlet 3 at the bottom. A flour sifting tank 4 is located below the flour accommodating basin 2, and a flour sifting trough 5 is accommodated in the flour accommodating tank 4, which flour sifting trough 5 is provided with flour sifting holes (not visible) at its bottom. The flour sifting device 1 also comprises a transmission (or motor) device 6, said transmission device 6 being used to rotatably drive a rotary brush shaft or rotating shaft 7 that is set in the flour sifting tank 4. The rotary brush shaft or rotating shaft 7 is provided with silicone brushes 8 that are helically distributed in space, as will be described in detail later. The rotary brush shaft 7 is rotated in order to brush the flour sifting holes with said silicone brushes 8. A fine flour basin 9 is located below the flour sifting tank 4 and fine flour in a flour mixture being sifted through the flour sifting holes of the flour sifting tank 4 or trough 5 will fall into the fine flour basin 9. Furthermore, a coarse flour basin 10 is located below the flour sifting tank 4 on one side far away from the first flour outlet 3, and coarse flour or flour lumps, after being sifted by the flour sifting tank 4 or trough 5, will be transported laterally under action of the helical brushes 8 and slide into the coarse flour basin 10 via a flour discharge passage 11 located on one side of the flour sifting tank 4.
[0066] This functioning is similar to the functioning of the sifting device described in WO 2023/117787 A1, the entire contents of which is herewith incorporated by reference in the present description.
[0067] FIG. 2 shows the rotating shaft 7 in isolated and disassembled form. The rotating shaft 7 has a square cross-section. At one end, there is a stop 7a that serves as an abutment for one of the brush modules (cf. FIGS. 3 ff). The stop 7a has at least one recess 7b, a function of which will become apparent later. At the other end, there is a threaded protrusion 7c for securing thereon a holding element 7d having a protrusion 7e that is complementary to recess 7b by means of a threaded washer 7f. Reference sign LA denotes a longitudinal axis of the rotating shaft 7, which coincides with a rotation axis thereof.
[0068] FIGS. 3 and 4 show different perspective views of a brush module 12, a plurality of which are used in the context of the present invention to constitute the rotating brush or the silicone brushes 8 mentioned earlier. However, while silicone is a preferred material in this context, the invention is not limited to this choice of material. Furthermore, as stated before, the present disclosure shall also encompass a design in which the rotating brush is not made from distinct, separate brush modules 12, but in integral from, as shown, e.g., in WO 2023/117787 A1.
[0069] Brush module 12 can be entirely made from silicone or it can be made therefrom in its outer portion 12a, whereas an inner portion 12b is made from a different material, e.g., a plastics material or metal or a combination of different materials, including coating. The outer portion 12a forms a brush element 12c that has indentations 12d along its outer periphery. The brush element 12c is formed helically with respect to a central axis A of the brush module 12 that coincides with said longitudinal axis LA (cf. FIG. 2).
[0070] Brush module 12 has a central through-hole 12e of square cross-section in its inner portion 12b that is intended to accommodate rotating shaft 7 (cf. FIG. 2). Inner part 12b has, on one side of central through-hole 12e, a protrusion 12f as denoted in FIG. 4 that can mate with or engage recess 7b (cf. FIG. 2). On the other side, diametrically opposite, as denoted in FIG. 3, inner part 12b has a complementary recess 12g, that can mate with a mirrored protrusion 12f on the backside of another identical adjacent brush module 12, as can be seen at least in part from FIG. 4. A further mirrored recess 12g (cf. FIG. 4) on the backside can mate with protrusion 7e (cf. FIG. 2). This ensures on the one hand a torsion-proof connection between rotating shaft 7 (cf. FIG. 2) and brush module 12 as well as between adjacent brush modules 12 and, on the other hand, a predefined relative orientation of the brush modules 12, so that they collectively form a screw conveyor, as desired, with pitch P.
[0071] Brush modules 12 further have recesses 12i in respective free edges of brush element 12c that are intended for engaging an additional stirring bar, as will become apparent later (cf. FIGS. 5 and 6).
[0072] As also shown in FIGS. 3 and 4, there is only one brush element 12c per brush module 12, which brush element 12c extends circumferentially over essentially an entire circle (approx.) 360, as seen in the direction of axis A. However preferably, as will become apparent from FIGS. 5 and 6, brush element 12c covers somewhat less than 360 such that there is a small open gap between said free edges.
[0073] FIGS. 5 and 6 show a plurality of brush modules 12 arranged and secured on rotating shaft 7 by means of washer 7f. They mutually engage by means of their central protrusions and recesses, as explained earlier. The same holds, mutatis mutandis, with respect to rotating shaft 7 and its components (cf. FIG. 2). In this way, all of the brush modules 12 are aligned with the free edges of their respective brush elements 12c. Further, in this way said gaps, if present, are aligned as well parallel to the longitudinal axis LA (cf. FIG. 2) of the rotating shaft 7.
[0074] According to FIG. 5, a stirring bar or baffle 13 of flat cuboid shape with thickened end and lower edges 13a, 13b, which is somewhat shorter than rotating shaft 7 so that one pitch P width remains open at both ends of the arrangement, can be inserted into said aligned gaps of the brush modules 12, cf. FIG. 6. In this way, thickened lower edge 13b engages said recesses 12i (cf. FIG. 4) for increased stability and positive (form) fit. The same holds with respect to said thickened end edges 13a and said free edges of the first and last brush modules 12, respectively.
[0075] As can be seen from FIG. 6, stirring bar 13 extends essentially as far in a radial direction (i.e., perpendicular to axis LA, cf. FIG. 2) as the brush elements 12c.
[0076] FIGS. 7 and 8 show another embodiment of the brush modules 12. Only the important differences with respect to FIGS. 3 and 4 will be explained in detail.
[0077] Brush modules 12 of FIGS. 7 and 8 have integrated (integral) stirring elements 12j on both sides (in the axial direction) of brush element 12c. These stirring elements 12j extend on both sides (in the radial direction) of central through-hole 12e and are aligned along the radial direction with a diameter of brush module 12. Overall, the combined stirring elements 12j are of essentially constant width (as measured in the direction of axis A, cf. FIG. 8), with exception of recess 12k that is intended for keeping an area near the shaft free of stirring elements and for facilitating installation of the brush or auger arrangement in the flour sifting device.
[0078] With such a design of the brush modules, no additional stirring bar 13 (cf. FIGS. 5 and 6) is required.
[0079] FIGS. 9 and 10 show the assembled state (rotating shaft 7 according to FIG. 2) and a plurality of brush modules 12 according to FIGS. 7 and 8, wherein all of the stirring elements 12j are located at the same circumferential position(s). According to FIGS. 9 and 10, this is equivalent to having two stirring bars or baffles.
[0080] FIGS. 11 ff relate to a different embodiment that comprises essentially different brush modules 12*, wherein each brush module 12* comprises a plurality of brush elements 12c* of particular shape(s), as will be explained with reference to FIGS. 13 and 14. As before, cf. FIGS. 2 to 10, the brush modules 12* are arranged and secured on a (slightly modified) rotating shaft 7*, as can best be seen from FIGS. 11 and 12.
[0081] Reference numerals for brush modules 12* are the same as for brush modules 12, cf. above, where applicable, the only difference being the additional asterisk * The same applies to the rotating shaft 7 *. Again, only the most important deviations from the designs that were already explained in detail will be addressed.
[0082] According to FIGS. 11 and 12 rotating shaft 7* comprises a hollow middle portion 7a* of square cross-section in which are insertable, at respective ends thereof, a first end piece 7b* and a second end piece 7c*, respectively, that serve as abutments in order to secure or clamp the brush modules 12* on the rotating shaft 7 *. Rotating shaft 7*, in its middle portion 7a*, comprises an eccentrical longitudinal protrusion 7d* (cf. FIG. 12) that serves to align the brush modules 12*, as will become apparent later.
[0083] In a preferred alternative embodiment that is shown in FIG. 12A, an eccentrical protrusion in analogy to element 7d* of FIG. 12 is provided on said second end piece 7c* only, which can be sufficient to secure the brush modules 12* on the rotating shaft 7* (cf. FIG. 11).
[0084] FIGS. 13 and 14 show two different views of the brush module 12* already shown in FIG. 11. It comprises ten (10) brush elements 12c* with distal indentations 12d* that are arranged in two (2) parallel star-shaped configurations with five brush elements 12c* each, which five brush elements 12c* are equally distributed in the circumferential direction and are inclined to constituteconjointlya helically shaped conveyor ensemble for lateral transport of sieving material (flour). However, two of the brush elements 12c* per star-shaped configuration (denoted X in FIGS. 13 and 14) are oriented in an opposite direction with respect to the helical shape (also referred to as an inverted brush element). These inverted brush elements X serve to slow down lateral transport, just like the stirring bar and stirring elements that were described earlier. It should be noted that more than two brush elements 12c* or only one brush element 12c* could be inverted in this way and/or that different brush elements 12c* could be inverted differently, i.e., with different tilt angles.
[0085] Of course, the invention is neither limited to a particular number of brush elements 12c* per brush module 12* nor to a particular number of parallel configurations, which merely serve to reduce the total number of brush modules 12 *.
[0086] Please note that the brush modules 12* adopt a modified approach with respect to the protrusions and recesses 12f, 12g described earlier (cf. FIGS. 3, 4 and 7, 8) by tilting an entire contact contour 121* of brush modules 12* with respect to axis A*. Furthermore, the brush modules 12* have an eccentrical groove 12m* that is supposed to engage the eccentrical longitudinal protrusion 7d* (cf. FIG. 12). In this way there is only one possibility of (correctly) mounting the brush modules 12* on rotating shaft 7* (cf. FIGS. 11 and 12).
[0087] FIG. 15 shows the mounted arrangement in a sectional view. Note that adjacent brush modules 12* connect in positive or form fitting manner for torsional strength.
[0088] FIGS. 16 and 17 show two different perspective views of the arrangement in FIG. 15.
[0089] As stated before, the present disclosure also comprises embodiments wherein the rotary brush is not composed of a plurality of brush modules (reference numerals 12 and 12*) but is devised in the form of one integral element. For instance, the features relating to the stirring bar (FIGS. 5 and 6) or to the stirring elements (FIGS. 7 to 10) or to the star-like configuration with at least one inverted brush element (FIGS. 11 ff) can also be implemented independently without said modular composition of the rotary brush.
