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. A brushless sieve cleaner for cleaning a sieving surface of a sieve box, said sieve box comprising the sieving surface and a sieve floor, the sieve cleaner comprising: a wobble foot extending along a main axis of the brushless sieve cleaner and configured such that the wobble foot can be positioned on the sieve floor and the brushless sieve cleaner can be tilted around about the wobble foot; and at least one cleaning element with a cleaning region, which comprises no brushes or bristles, and the, or each, cleaning region having a plurality of cleaning surfaces for cleaning the sieving surface; wherein each individual one of the plurality of cleaning surfaces is configured and arranged so as to be capable of making contact with the sieving surface along at least a line of contact, whereby upon rotation of the brushless sieve cleaner about the main axis, each cleaning surface sweeps out a planar region, and each of the plurality of cleaning surfaces is separated from each neighboring cleaning surface by a slot formed in the cleaning region, wherein each slot extends in a slot direction which is at an angle to a radial direction with respect to the main axis which is in a range of 30 to 60.

2. The brushless sieve cleaner as claimed in claim 1, wherein each of the planar regions swept across by each of the cleaning surfaces defines a notional cleaning line which corresponds to a radial dimension of the planar region in a radial direction with respect to the main axis; and the cleaning surfaces and the slots are configured and arranged in such a manner that any gap which may exist between the notional cleaning line of a first one of the cleaning surfaces and the notional cleaning line of a neighboring one of the cleaning surfaces has a length of less than the length of the notional cleaning line of the first one of the cleaning surfaces.

3. The brushless sieve cleaner as claimed in claim 1, wherein the cleaning elements exhibit a height parallel to the main axis and the slots exhibit a depth parallel to the main axis, and the depth of the slots is greater than 0% and less than or equal to 20% of the height of the cleaning elements.

4. The brushless sieve cleaner as claimed in claim 1, wherein the brushless sieve cleaner has a central region which contains the main axis with an upper side opposite the wobble foot which is recessed with respect to the cleaning surfaces such that the central region cannot be brought into contact with the sieving surface.

5. The brushless sieve cleaner as claimed in claim 1, wherein the sieve cleaner comprises at least three cleaning elements each with a cleaning region, each cleaning region comprises a plurality of cleaning surfaces for cleaning the sieving surface and the cleaning elements, the cleaning regions and the cleaning surfaces are arranged and configured such that when the brushless sieve cleaner is positioned on the sieve floor and when the sieve box is at a standstill and when the sieving surface is taut, more than 50% of the cleaning surfaces of at least two of the cleaning elements are simultaneously in contact with the sieving surface, but it is not possible for all of the cleaning surfaces of all of the cleaning elements to be simultaneously in contact with the sieving surface.

6. The brushless sieve cleaner as claimed in claim 1, wherein the brushless sieve cleaner has an odd number of cleaning elements.

7. The brushless sieve cleaner as claimed in claim 1, wherein the cleaning element(s) is/are configured as cleaning arm(s) which extend(s) radially outward from a central region of the brushless sieve cleaner containing the main axis.

8. The brushless sieve cleaner as claimed in claim 7, wherein the cleaning surfaces are arranged in a single row along the cleaning arms.

9. The brushless sieve cleaner as claimed in claim 7, wherein the cleaning arms have a length which falls within a range of 5 to 15 cm.

10. The brushless sieve cleaner as claimed in claim 1, wherein the brushless sieve cleaner has at least one clearer for clearing out fine material found on the sieve floor through an opening formed in the sieve box.

11. A sieve unit containing: at least one sieve box with a sieve floor and a sieving surface; at least one brushless sieve cleaner which is positioned on the sieve floor, wherein the brushless sieve cleaner comprises a wobble foot which extends along a main axis of the brushless sieve cleaner and is configured in such a manner that the wobble foot can be positioned on the sieve floor and the brushless sieve cleaner can be tilted around about the wobble foot, and the brushless sieve cleaner further comprises at least three cleaning elements each with a cleaning region, each cleaning region comprises a plurality of cleaning surfaces for cleaning the sieving surface, and the cleaning elements, the cleaning regions and the cleaning surfaces are arranged and configured such that when the brushless sieve cleaner is positioned on the sieve floor and when the sieve box is at a standstill and when the sieving surface is taut, more than 50% of the cleaning surfaces of at least two of the cleaning elements are simultaneously in contact with the sieving surface, but it is not possible for all of the cleaning surfaces of all of these cleaning elements to be simultaneously in contact with the sieving surface, each of the plurality of cleaning surfaces is separated from each neighboring cleaning surface by a slot formed in the cleaning region, wherein each slot extends in a direction which is at an angle to a radial direction with respect to the main axis which is in a range of 30 to 60.

12. The sieve unit as claimed in claim 11, wherein the wobble foot, the cleaning elements, the cleaning regions, the cleaning surfaces and the sieve box are arranged and configured with respect to one another such that when the sieve box is at a standstill and when the sieving surface is taut and when the wobble foot is positioned on the sieve floor, each and every one of the cleaning surfaces of all of the cleaning elements of all the cleaning regions is either in contact with the sieving surface or is spaced by less than 5 mm from the sieving surface.

13. A method of upgrading or modifying a sieve box, involving a step in which a brushless sieve cleaner is placed on a sieve floor of the sieve box such that a sieve unit is formed comprising at least said sieve box and said brushless sieve cleaner, wherein the brushless sieve cleaner is a brushless sieve cleaner for cleaning a sieving surface of the sieve box, said sieve box containing the sieving surface and the sieve floor, the brushless sieve cleaner comprising: a wobble foot extending along a main axis of the brushless sieve cleaner and configured such that the wobble foot can be positioned on the sieve floor and the brushless sieve cleaner can be tilted around about the wobble foot; and at least three cleaning elements each with a cleaning region, which comprises no brushes or bristles, and each cleaning region has a plurality of cleaning surfaces for cleaning the sieving surface, and wherein each of the plurality of cleaning surface is separated from each neighboring cleaning surface by a slot formed in the cleaning region, wherein each slot extends in a direction which is at an angle to a radial direction with respect to the main axis which is in a range of 30 to 60; each individual one of the plurality of cleaning surfaces is configured and arranged so as to be capable of making contact with the sieving surface along at least a line of contact, whereby upon rotation of the brushless sieve cleaner about the main axis each cleaning surface sweeps out a planar region, each of the plurality of cleaning surfaces is separated from each neighboring cleaning surface by a slot formed in the cleaning region, and the cleaning elements, the cleaning regions and the cleaning surfaces are arranged and configured such that when the brushless sieve cleaner is positioned on the sieve floor and when the sieve box is at a standstill and when the sieving surface is taut, more than 50% of the cleaning surfaces of at least two of the cleaning elements are simultaneously in contact with the sieving surface, but it is not possible for all of the cleaning surfaces of all of the cleaning elements to be simultaneously in contact with the sieving surface.

Description

(1) The invention is explained in greater detail below with the help of a plurality of exemplary embodiments and drawings. In these

(2) FIG. 1: shows a first sieve cleaner according to the invention as a perspective view;

(3) FIG. 2: shows a second sieve cleaner according to the invention as a perspective view;

(4) FIG. 3: shows a third sieve cleaner according to the invention as a perspective view;

(5) 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;

(6) FIG. 5: shows a fourth sieve cleaner according to the invention as a perspective view;

(7) FIG. 6: shows the fourth sieve cleaner according to the invention as a first side view;

(8) FIG. 7: shows the fourth sieve cleaner according to the invention as a second view;

(9) FIG. 8: shows the fourth sieve cleaner according to the invention as a plan view;

(10) FIG. 9: shows a sectional view of the fourth sieve cleaner according to the invention along the line A-A according to FIG. 8;

(11) FIG. 10: shows a side view of the fourth sieve cleaner according to the invention housed in a sieving tray.

(12) 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.

(13) 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 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.

(14) 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.

(15) 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.

(16) 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.

(17) 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 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.

(18) 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.

(19) 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.

(20) 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.

(21) 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.

(22) 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.

(23) 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%.

(24) 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.