SIEVE CLEANERS, SIEVE UNIT, AND METHODS

Abstract

Sieve cleaners (1) for cleaning a sieve surface (2) of a sieve box (3), which sieve box contains a sieve surface (2) and bottom (4). The sieve cleaners (1) contain a wobble foot (5), which extends along a main axis (A) of the sieve cleaner (1) and is designed such that the wobble foot can be placed onto the sieve bottom (4) and the sieve cleaner (1) can be tipped about the wobble foot (5). At least one cleaning element (6) has a cleaning region (7), and each cleaning region (7) has a plurality of cleaning surfaces (8) for cleaning the sieve surface (2). The cleaning surfaces (8) are each designed for at least linear contact with the sieve surface (2) and are separated from one another by slots (9) formed in the cleaning region (7). Sieve units and methods for upgrading or converting a sieve box are also disclosed.

Claims

1-14. (canceled)

15. A sieve cleaner for cleaning a sieving surface of a sieving tray, said sieving tray containing the sieving surface and a sieve bottom, the sieve cleaner comprising: a wobble foot extending along a main axis of the sieve cleaner and configured such that the wobble foot can be placed on the sieve bottom and the sieve cleaner can be tilted around about the wobble foot; at least one cleaning element with a cleaning region, and the, or each, cleaning region having a plurality of cleaning surfaces for cleaning the sieving surface; wherein the cleaning surfaces are each designed for an at least linear contact with the sieving surface and are separated from one another by slots formed in the cleaning region.

16. The sieve cleaner as claimed in claim 15, wherein the slots extend in a slot direction which forms an angle with a radial direction in respect of the main axis which is in the region of 0° to 90°.

17. The sieve cleaner as claimed in claim 15, wherein the cleaning surfaces are configured and arranged such that when there is rotation about the main axis, the cleaning surfaces sweep over an imaginary cleaning line in each case, in a radial direction with respect of the main axis, and a ratio of the radial spacing of two adjacent cleaning lines and the radial length of the cleaning lines lies in a region of 50% and 100%.

18. The sieve cleaner as claimed in claim 15, wherein the cleaning elements exhibit a height parallel to the main axis and the slots exhibit a depth parallel to the main axis, and a ratio between the depth of the slots and the height of the cleaning elements is greater than 0% and less than or equal to 20%.

19. The sieve cleaner as claimed in claim 15, wherein the sieve cleaner has a center region which contains the main axis with an upper side opposite the wobble foot which is recessed with respect of the cleaning surfaces such that it cannot be brought into contact with the sieving surface.

20. The sieve cleaner as claimed in claim 15, wherein the sieve has at least three cleaning elements each with a cleaning region, each cleaning region has a plurality of cleaning surfaces for cleaning the sieving surface and the cleaning surfaces are arranged and configured such that when the sieving tray is inoperative and when the sieving surface is tightly stretched, the cleaning surfaces of at least two of the cleaning elements, but not the cleaning surfaces of all of the cleaning elements, are simultaneously in contact with the sieving surface, and in this case substantially all cleaning surfaces of these cleaning elements are in contact with the sieving surface.

21. The sieve cleaner as claimed in claim 15, wherein the sieve cleaner has an odd number of cleaning elements.

22. The sieve cleaner as claimed in claim 15, wherein the cleaning element(s) is/are configured as cleaning arm(s) which extend(s) from a central region of the sieve cleaner containing the main axis radially outwards.

23. The sieve cleaner as claimed in claim 22, wherein the cleaning surfaces are arranged in a single row along the cleaning arms.

24. The sieve cleaner as claimed in claim 22, wherein the cleaning arms has a length which falls within a range of 5 to 15 cm.

25. The sieve cleaner as claimed in claim 15, wherein the sieve cleaner has at least one clearer for clearing out fine material found on the sieve bottom through a clearing opening formed in a sieve frame of the sieving tray.

26. A sieve unit containing: at least one sieving tray with a sieve bottom and a sieving surface; at least one sieve cleaner which can be placed or is placed on the sieve bottom, wherein the sieve cleaner has at least three cleaning elements each with a cleaning region, each cleaning region has a plurality of cleaning surfaces for cleaning the sieving surface and the cleaning surfaces are arranged and configured such that when the sieving tray is inoperative and when the sieving surface is tightly stretched, the cleaning surfaces of at least two of the cleaning elements, but not the cleaning surfaces of all cleaning elements, are simultaneously in contact with the sieving surface, and in this case substantially all cleaning surfaces of these cleaning elements are in contact with the sieving surface.

27. The sieve unit as claimed in claim 26, wherein the sieve cleaner and the sieving tray are configured and adjusted to one another such that when the sieving tray is at a standstill, when the sieving surface is tightly stretched and when the wobble foot is placed on the sieve bottom, the cleaning surfaces of all cleaning elements have a spacing of less than 5 mm from the sieving surface.

28. A method of upgrading or modifying a sieving tray, involving a step in which a sieve cleaner is placed on a sieve bottom of the sieving tray, wherein the sieve cleaner is a sieve cleaner for cleaning a sieving surface of the sieving tray, said sieving tray containing the sieving surface and the sieve bottom, the sieve cleaner comprising: a wobble foot extending along a main axis of the sieve cleaner and configured such that the wobble foot can be placed on the sieve bottom and the sieve cleaner can be tilted around about the wobble foot; and at least three cleaning elements each with a cleaning region, and each cleaning region has a plurality of cleaning surfaces for cleaning the sieving surface; the cleaning surfaces are each designed for an at least linear contact with the sieving surface and separated from one another by slots formed in the cleaning region, the sieve cleaner is placed on the sieve bottom such that a sieve unit is formed which contains at least said sieving tray with the sieve bottom and the sieving surface, the cleaning surfaces are arranged and configured such that when the sieving tray is inoperative and when the sieving surface is tightly stretched, the cleaning surfaces of at least two of the cleaning elements, but not the cleaning surfaces of all cleaning elements, are simultaneously in contact with the sieving surface, and in this case substantially all cleaning surfaces of these cleaning elements are in contact with the sieving surface.

Description

[0035] The invention is explained in greater detail below with the help of a plurality of exemplary embodiments and drawings. In these

[0036] FIG. 1: shows a first sieve cleaner according to the invention as a perspective view;

[0037] FIG. 2: shows a second sieve cleaner according to the invention as a perspective view;

[0038] FIG. 3: shows a third sieve cleaner according to the invention as a perspective view;

[0039] FIG. 4: shows a diagram illustrating the cleaning lines swept over by the cleaning surfaces of the sieve cleaners according to FIGS. 2 and 3;

[0040] FIG. 5: shows a fourth sieve cleaner according to the invention as a perspective view;

[0041] FIG. 6: shows the fourth sieve cleaner according to the invention as a first side view;

[0042] FIG. 7: shows the fourth sieve cleaner according to the invention as a second view;

[0043] FIG. 8: shows the fourth sieve cleaner according to the invention as a plan view;

[0044] FIG. 9: shows a sectional view of the fourth sieve cleaner according to the invention along the line A-A according to FIG. 8;

[0045] FIG. 10: shows a side view of the fourth sieve cleaner according to the invention housed in a sieving tray.

[0046] The first embodiment of the sieve cleaner 1′ shown in FIG. 1 contains a wobble foot that cannot be identified here. Said wobble foot extends along a main axis A′ of the sieve cleaner 1′ which also simultaneously forms one of its neutral axes. It is configured like the wobble foot 5 in the fourth exemplary embodiment according to the invention in FIGS. 5 to 9.

[0047] From a center region 10′ of the sieve cleaner 1′ extend three cleaning elements configured as cleaning arms 6′ which are distributed uniformly about the neutral axis A′ in the circumferential direction. Each of the cleaning arms 6′ contains a cleaning region 7′ in each case. Each of the cleaning regions 7′ has a plurality of rectangular cleaning surfaces 8′ which run perpendicularly to the neutral axis A′ and are each configured for planar contact with a sieve surface not depicted here (see FIG. 10 for this, which shows a sieving tray and a sieve cleaner according to the invention arranged therein). The cleaning surfaces 8′ are separated from one another by the slots 9′ formed in the respective cleaning region 7′. In the first exemplary embodiment shown here, the slots 9′ extend along a slot direction S′ at an angle α′ of 90° to a radial direction R′ in respect of the neutral axis A′. In other words, the slots 9′ therefore extend perpendicularly to the longitudinal direction of the cleaning arms 6′.

[0048] There are also cleaning regions 18′ in each case in the region between two of the cleaning arms 6′, in other words in the center region 10′ of the sieve cleaner 1′. In addition, the center region 10′ contains three openings 19′ through which fine material can pass. When the sieving tray is at a standstill and the sieving surface is tightly stretched, the cleaning surfaces 8′ of exactly two of the cleaning arms 6′ can always be brought into contact simultaneously with the sieving surface, wherein in this case substantially all cleaning surfaces 8′ of these two cleaning arms 6′ can be brought into contact with the sieving surface.

[0049] The second sieve cleaner 1″ according to the invention shown in FIG. 2 differs from that shown in FIG. 1 in that in the center region 10″ there are neither cleaning regions 18′ nor openings 19′. Due to the non-existence of cleaning regions 18′ in the center region 10″, there is contact between the sieve cleaner 1″ and the sieving surface only in the tilted state of the sieve cleaner 1″. This means that a braking or even a jamming of the sieve cleaner 1″ between the sieve bottom and the sieving surface can be prevented before said cleaner can tilt at all.

[0050] FIG. 3 shows a third sieve cleaner 1′″ according to the invention which likewise contains three cleaning arms 6′″ distributed uniformly in the circumferential direction. The sieve cleaner 1′″ also has a wobble foot 5′″ which is rounded at the lower end, as a result of which tilting of the sieve cleaner 1′″ is made easier.

[0051] Unlike the exemplary embodiments depicted in FIGS. 1 and 2, the slots 9′″ formed between the cleaning surfaces 8′″ run in a slot direction S′″ which creates an angle α′″ of 45° in relation to a neutral axis A′″ in the radial direction R′″. This angle creates a particularly advantageous compromise between the linear support and sliding friction between the sieve cleaner 1′″ and sieving surface. Furthermore, at the ends of the cleaning arms 6′″, reinforcements 11′″ are provided in a plane running perpendicularly to the main axis A′″, said reinforcements acting as impact protectors and reducing the risk of damage to the cleaning regions when the sieve cleaner 1′″ strikes a sieve frame.

[0052] This is explained in greater detail with the help of FIG. 4. This shows a plan view on the left of a detail of a cleaning arm 6″ of the sieve cleaner 1″ according to FIG. 2 and also, on the right, a plan view of a detail of a cleaning arm 6′″ of the sieve cleaner 1′″ according to FIG. 3. During movement in the circumferential direction U, the cleaning surfaces 8″ or 8′″ each sweep over an imaginary cleaning line L″ or L′″. Due to the oblique position of the cleaning surfaces 8′″ and the slots 9′″, for the third exemplary embodiment depicted on the right, the ratio of the radial length of the cleaning lines L″ and the spacing of two adjacent cleaning lines L″ is greater than is the case in the second exemplary embodiment depicted on the left. The linear support is therefore greater in the third exemplary embodiment than in the second. For this reason, the third sieve cleaner 1′″ produces more efficient cleaning than the first sieve cleaner 1″.

[0053] In FIGS. 5 to 9, a preferred sieve cleaner 1 is depicted in a fourth exemplary embodiment. This sieve cleaner 1 may be produced in one piece by injection molding, for example, from the Elastollan® already referred to above. This sieve cleaner 1 also has a wobble foot 5 which extends along a neutral axis A forming the main axis of the sieve cleaner 1. The wobble foot 5 is configured in such a manner that it can be placed on a sieve bottom and the sieve cleaner 1 is tiltable about the wobble foot 5. The wobble foot 5 is, in addition, rounded at the lower end, as a result of which tilting of the sieve cleaner 1 is simplified. The three cleaning arms 6 are also uniformly distributed about the neutral axis A in the circumferential direction in this case. At the ends of the cleaning arms 6, reinforcements 11 are also provided in this exemplary embodiment in a plane running perpendicularly to the main axis A, said reinforcements acting as impact protectors and reducing the risk of damage to the cleaning regions when the sieve cleaner 1 strikes a sieve frame.

[0054] Unlike the sieve cleaner 1′″ according to FIG. 3, the upper side 15 of the center region 10 is recessed in respect of the cleaning surfaces 8 of the cleaning arms 6, in such a manner that said upper side 15 cannot be brought into contact with a sieving surface. This results in the same advantages as those that have already been explained in connection with FIG. 2. Furthermore, the sieve cleaner 1 contains a clearer 12, with the help of which fine material located on a sieve bottom can be cleared through a clearing opening formed in a sieve frame of the sieving tray.

[0055] FIG. 6 shows a first side view of the fourth sieve cleaner 1, FIG. 7 a second side view and FIG. 8 a plan view.

[0056] FIG. 9 shows a detailed sectional view along the line A-A according to FIG. 8. It can be seen from this that the cleaning surfaces 8 are rounded. However, because they run in a straight line perpendicularly to this sectional view, a linear contact with a planar sieving surface is made possible.

[0057] According to FIG. 9, parallel to the neutral axis A that cannot be seen here, the slots 9 exhibit a depth t=1.5 mm. The ratio between this depth t and the height h of the cleaning arms 6 is roughly 10%.

[0058] Finally, a sieve unit is shown in FIG. 10 which contains a sieving tray 3 and one of the preferred sieve cleaners 1 according to the invention. The sieving tray 3 has a horizontal sieve bottom 4, a sieve frame 13 extending in a vertical direction therefrom and also a sieving surface configured as a sieve fabric 2 which is stretched over the sieve frame 13. The sieve cleaner 1 is placed with its wobble foot 5 on the sieve bottom 4. When the sieving tray 3 is at a standstill and the sieve fabric 2 is tightly stretched, the cleaning surfaces of exactly two of the cleaning arms 6 are always simultaneously in contact with the sieve fabric 2. In this case, substantially all cleaning surfaces 8 of these two cleaning arms 6 are then in contact with the sieve fabric 2. In addition, the sieve cleaner 1 is configured in such a manner that the cleaning surfaces 8 of all cleaning arms 6 are constantly at a distance of less than 1.4 mm from the sieve fabric 2.