Screen tensioner for tensioning screen liner

Abstract

The invention relates to a screen tensioner (40) for tensioning a screen liner (20) of a screening machine (10), having a rod-shaped or segmented tensioning section (41) which has a fastening section (46) in the region of each of the two longitudinal ends thereof. According to the invention, the tensioning section (41) has a first tensioning projection (42) forming a first tensioning edge (42.1) in the region of a first tensioning end and a second tensioning projection (43) forming a second tensioning edge (43.1) on an opposite second tensioning end, the first tensioning edge (42.1) and the second tensioning edge (43.1) extending between the two fastening sections (46), the first tensioning edge (42.1) forms a first tensioning profile, the second tensioning edge (43.1) forms a second tensioning profile, and the first tensioning profile and the second tensioning profile have different geometries. In this manner, a method is provided for the user to easily tension different types of screen liners using one screen tensioner (40).

Description

Technical Field

[0001] The invention relates to a screen tensioner for tensioning a screen lining in a screening machine, wherein the screen tensioner has a rod-shaped or segmented tensioning section which has a fastening section in the region of each of its two longitudinal ends.

[0002] The invention also relates to a screening machine comprising a screen tensioner. Background Art

[0003] DE 2501 750A discloses a screening machine crusher with a screen tray. Three screen liners are superimposed inside the screen tray. These screen liners are designed as wire frames, which have folded edges at their longitudinal ends. The folded edges are bent in the direction from the top to the bottom of the screen lining. The folded edges have a V-shaped cross section. A screen tensioner designed in the form of a rod engages with these folded edges. The screen tensioner has a tensioning protrusion, which forms a tensioning edge at one tensioning end. The tensioning edge rests against the base of the folded edge. At the longitudinal ends, the screen tensioner has a fastening section, on which a tensioning element acts to tension the screen lining in the screen tray.

[0004] When this known device is used to tension the screen tensioner, the screen tension is non-uniform along the length of the screen tensioner. As a result, there are areas of the screen that are subject to a greater preload than adjacent areas of the screen. The different screen tensions lead to vibratory behavior of the screen lining, which leads to premature failure before the maximum service life of the screen lining is reached.

[0005] EP 0 238 455 A2 discloses a screening machine in which a screen tensioner in the form of a hollow segment is used for pre-tensioning the screen lining. The screen tensioner has molded tensioning protrusions forming a tensioning edge.

[0006] This problem is exacerbated if different types of screen linings are optionally installed by the user. A solid screen lining requires a greater preload than a less solid screen lining. Therefore different screen tensioners must be used for different types of screen linings. The user must then ensure that the correct screen tensioner is assigned to each screen lining. Summary of the invention

[0007] The present invention solves the problem of providing the user with a simple way of tensioning different types of screen linings.

[0008] The solution to this problem is that the tensioning section of the screen tensioner has a first tensioning protrusion in the area of ​​a first tensioning end, which first tensioning protrusion forms a first tensioning edge, and has a second tensioning protrusion on the opposite second tensioning end, which second tensioning protrusion forms a second tensioning edge, the first tensioning edge and the second tensioning edge extend between the two fastening sections, and the first tensioning edge forms a first tensioning contour, the second tensioning edge forms a second tensioning contour, and the first tensioning contour and the second tensioning contour have different geometric shapes.

[0009] Since the screen tensioner has two tensioning edges, it can bring one or the other tensioning edge into tensioning engagement with the screen lining to be assembled. The tensioning edges have different geometries and are therefore designed for the respective screen lining. This allows the user to use one screen tensioner to tension two different screen linings in one screening device without having to replace the screen tensioner. The same screen tensioner can be used, preferably in an inverted manner, in two different mounting positions. This greatly facilitates the maintenance of the screening machine.

[0010] According to the invention, one of the two tensioning edges can be convex with a curvature extending between the two fastening sections, while the other tensioning edge can be convex or concave with a curvature extending between the two fastening sections, or the other tensioning edge can extend along a straight line between the two fastening sections. If one tensioning edge is convex and the other is concave, it is advantageous if the two tensioning edges follow a profile that differs from one another, preferably such that the amount of curvature at the two ends is different.

[0011] The curvature of the convex tensioning edge of a tensioning protrusion can be designed for the matching screen lining in order to clamp it in the screen tray with the most uniform tension possible. When tensioning the screen lining, the tensioning edge with the most protruding area first comes into contact with the designated fastening edge of the screen lining and tensions it there. When the screen tensioner is further tensioned, it deforms elastically, wherein the remaining area of ​​the tensioning edge gradually comes into contact with the screen lining and tensions it. As a result, a uniform tension is achieved over the entire width of the screen lining. This takes into account the fact that a uniformly tensioned screen lining has a longer service life and supports the inherent properties of the screen lining, such as self-cleaning.

[0012] If the second tensioning edge is also convex, the curvature can be designed for the corresponding screen surface to ensure that it is uniformly pretensioned.

[0013] If the second tensioning edge is concave, this type of screen tensioner is suitable for screen linings that require greater tension on both sides of the lining. Therefore, they first come into contact with the concave geometry of the screen tensioner.

[0014] If the second tensioning edge is straight, the screen tensioner can be used on straight edges of screen linings that require only a small screen tension. The second tensioning edge is therefore used, for example, for lightweight, delicate screen linings. This requires a smaller preload. Due to the lower pretensioning force, the strongly curved tensioning edge does not deform elastically to the same extent, so that the outer areas of the lightweight screen lining do not come into contact with the tensioning edge and remain untensioned.

[0015] According to the invention, it can be provided that the tensioning profiles of the first tensioning edge and the second tensioning edge each have a profile end section and a profile center between the profile end section in their end region facing the fastening section, so that when the tensioning edges are projected into the central transverse plane, the profile center of at least one tensioning edge is offset relative to the profile end section at the maximum arc in the tensioning direction or against the tensioning direction. Obviously, for example, the tensioning edges can be arranged convex or concave, wherein if the tensioning edge is concave, the amount of the arc is determined by the size of the notch. If the tensioning edge is convex, the amount of the arc is caused by the outwardly protruding protrusion of the tensioning profile. According to a first variant of the invention, the amount of the arc of the first tensioning edge can be arranged to be different from the arc of the second tensioning edge. In this way, two different tensioning profiles can be easily realized. The tensioning profiles of the two tensioning edges can be both convex or both concave, or one tensioning edge can be convex and the other tensioning edge can be concave.

[0016] However, preferably, the projection of one tensioning edge into the central transverse plane may form an arc, while the projection of the other tensioning edge into the central transverse plane may form a straight line. Thus, one tensioning edge may be convex or concave, while the other tensioning edge may be straight.

[0017] If a convex or concave geometry is used for the tensioning edge, it may preferably be arranged so that the amount of curvature is less than or equal to 25 mm. Such a screen tensioner is suitable for use in screening machines, which are used in conjunction with a rock crusher or a crusher for processing mineral materials. The maximum length of the screen tensioner is preferably less than 1800 mm.

[0018] According to the invention, it can be provided that the tensioning section has a top and a bottom, and that the screen tensioner is designed symmetrically at least in the region of its tensioning section with respect to a central transverse plane extending between the top and the bottom. The screen tensioner can be easily mounted on the covering and has a compact design.

[0019] If provision is made for the first clamping edge and / or the second clamping edge to have a rounded corner extending between the top and the bottom of the clamping section, stress peaks which are transmitted to the screen lining are avoided or reduced.

[0020] According to one variant of the invention, assembly is facilitated by at least one fastening section having at least one identification mark, which is assigned to the first tensioning end and / or the second tensioning end, wherein the identification mark is preferably designed as a recess and is further preferably incorporated into the longitudinal end of the fastening section.

[0021] A possible variant of the invention can be that the convex or concave tensioning edge is circular or elliptical in shape or consists of several profile segments. This allows the tensioning edge to be individually adapted to the screen lining. Preferably, the tensioning edge follows a continuously differentiable function in the direction between the two fastening segments to achieve a stress-optimized structure.

[0022] The problem of the invention is also solved with a screening machine having a screen arrangement with a screen lining, on which a screen tensioner according to any one of claims 1 to 8 acts.

[0023] In particular, it can be provided that the screen lining has a fastening edge at at least one of its longitudinal ends, which is designed in the form of a bend, and that one of the tensioning projections of the screen tensioner engages with the bend. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention is explained in more detail below based on the exemplary embodiments shown in the drawings.

[0025] In the accompanying drawings,

[0026] Figure 1 A side view of a screening machine is shown;

[0027] Figure 2 Shows Figure 1 A schematic diagram of a screen plate of a screening machine;

[0028] Figure 3 Shown for Figure 1 A partial perspective view of a tensioning device for a screen lining of a screening machine;

[0029] Figure 4 Shown for Figure 1 A top view and a partial view of a screen tensioner of a screening machine relative to a screen lining and as a horizontal section;

[0030] Figure 5 Shows Figure 4 the extended view that is rendered; and

[0031] Figure 6 Another embodiment of the present invention is shown, wherein Figure 1 A screen tray of a screening machine is shown in a schematic cross-sectional view through the screen lining. DETAILED DESCRIPTION

[0032] Figure 1 A screening machine 10 according to the invention is shown. The screening machine 10 is designed as a mobile screening machine 10. It is also conceivable that the invention can be used in a stationary screening machine.

[0033] The screening machine 10 has a chassis 11 supported by an underframe 11.1 to be able to move the screening machine. Preferably, the screening machine 10 has a feed hopper 12. A wheel loader can be used to fill the feed hopper 12 with material to be screened.

[0034] The feed hopper 12 has a transport device (e.g., a vibrating chute, a conveyor belt, a feed belt, or a silo discharge conveyor), by which the fed material can be conveyed to the feed belt 13. The feed belt 13 can be designed as an endless circulating conveyor belt. The feed belt 13 conveys the material to be screened to the screen device, which has a screen tray 60.

[0035] The screen device is used to screen out at least two fractions from the material fed. For this purpose, the screen device has at least one screen lining 20, such as Figure 2 shown.

[0036] Figure 1 It is also shown that the screen tray 60 has an end wall 61 which extends in the longitudinal direction of the screen.

[0037] The screen tray 60 is mounted on a fixed screen tray support 64 via a spring element 63. A drive 65 can be used to oscillate the screen tray 60 to screen the material.

[0038] At least one discharge belt 14.1, 14.2 or at least one fine grain or storage belt 15 is assigned to the screen device. In this exemplary embodiment, two discharge belts 14.1, 14.2 and one fine grain or storage belt 15 are used. Therefore, two screen linings 20 are installed in the screen device.

[0039] The material to be screened is fed to the upper screen lining 20. The material falling through the upper screen lining 20 reaches the lower screen lining 20. The material not falling through the upper screen lining 20 reaches one of the two discharge belts 14.1, 14.2. The material not falling through the second screen lining 20 reaches the second discharge belt 14.1, 14.2. The material falling through the two screen linings 20 in the form of fine material reaches the fine or storage belt 15. The two discharge belts 14.1, 14.2 and the fine or storage belt 15 convey the fine fraction fed thereto to the storage pile 16.

[0040] Figure 2Schematic diagram of a screen device is shown. As shown, a support element 30 is installed in a screen tray 60 to support a screen lining 20. The support element 30 has a mounting foot 32, by which the support element 30 is fixedly mounted in the screen tray 60. Opposite to the mounting foot 32, a damping element 31 is replaceably mounted on one end of the support element 30. The damping element 31 supports the screen lining 20 in the bottom area of ​​the screen 22.

[0041] The support element 30 may be arranged and aligned with its damping element 31 such that the screen lining 20 resting on the damping element 31 forms a curved profile in the longitudinal direction of the screen, such as Figure 2 shown.

[0042] Figure 2 The left-hand support element 30 has a retainer neck 33 at its end facing away from the mounting foot 32 . The screen lining 20 is held replaceably on the retainer neck 33 by means of the fastening edge 23 .

[0043] The screen lining 20 is designed as a flat element and has a screen top 21 opposite a screen bottom 22. The fastening edge 23 can be bent away from the end section 23.1 of the screen lining 20 to form a bend 23.2. The retaining lug 33 engages with this bend 23.2.

[0044] At the end facing away from the fastening edge 23, the screen lining 20 has a further fastening edge 24, which has essentially the same design as the fastening edge 23. Thus, the bend 24.2 bends away from the screen lining 20 at the opposite end section 24.1.

[0045] The screen liner 20 must be arranged longitudinally (i.e., in the screen tray 60) Figure 2 For this purpose, a screen tensioner 40 is used. Figure 3 and Figure 5 The cross-section of the screen tensioner 40 is shown to be substantially rectangular. Therefore, the screen tensioner 40 can have a rod-shaped geometry.

[0046] The screen tensioner 40 has a central tensioning section 41 which extends between two end fastening sections 46 .

[0047] The tensioning section 41 has tensioning projections 42, 43 at its opposite longitudinal ends. The first tensioning projection 42 has a first tensioning edge 42.1. The second tensioning projection 43 has a second tensioning edge 43.1.

[0048] The first clamping edge 42 . 1 extends in a convexly curved manner between the two fastening sections 46 , for example Figure 4 as shown in . Figure 4A horizontal section through a central transverse plane MQ of the screen tensioner 40 is shown. The central transverse plane MQ and thus the Figure 4 The cross section is Figure 3 Shown in.

[0049] Figure 4 It is shown that the first tensioning edge 42.1 forms a tensioning profile. The tensioning profile has profile end sections 49.1 at its longitudinal ends and a profile center 49.2 in the middle between the profile end sections 49.1. Figure 4 In the tensioning direction extending from right to left in the center, the projection of the first tensioning edge 42.1 in the center transverse plane MQ has a maximum curvature H in the region of the profile center 49.2. The profile center 49.2 is offset in the tensioning direction compared to the profile end section 49.1 due to the convex curvature, which causes this maximum curvature H. Preferably, the curvature H is less than 25 mm.

[0050] The second tensioning edge 43.1 opposite the first tensioning edge 42.1 also forms a tensioning profile. This tensioning profile also forms a profile end section 49.1 at the opposite end facing the fastening section 46. The profile center 49.2 is formed in the middle between the profile end sections 49.1. In this exemplary embodiment, the projection of the second tensioning edge 43.1 in the central transverse plane MQ extends in a straight line between the two fastening sections 46, such as Figure 4 However, it is also conceivable that the second tensioning edge 43.1 is convexly curved and has a maximum curvature which is preferably different from the maximum curvature H of the first tensioning edge 42.1.

[0051] It is also conceivable that the second tensioning edge 43.1 forms a concave profile. In this case, the profile center 49.2 has a negative curvature H. Preferably, the amount of the two curvatures H of the two tensioning edges 42.1, 43.1 deviate from each other.

[0052] In other words, the screen tensioner 40 realizes different tensioning contours at the two tensioning edges 42.1, 43.1.

[0053] As further shown, the screen tensioner 40 is preferably configured symmetrically with respect to the central transverse plane MQ.

[0054] In the exemplary embodiment shown, the screen tensioner 40 is Figure 2 The right-hand bend 24.2 shown in FIG. 1 engages with its first tensioning projection 42. The first tensioning edge 42.1 of the screen tensioner 40 contacts a base section 42.3 below the bottom of the screen 22, which is caused by the bend 24.2. The tensioning projection 42 is thus at least partially enclosed between the bottom of the screen 22 and the bend 24.2.

[0055] like Figure 3 As clearly shown, the fastening section 46 of the screen tensioner 40 passes through a feed-through 62 in a given end wall 61 of the screen tray 60 at the opposite end. The fastening section 46 thus protrudes on the outside beyond the end wall 61 of the screen tray 60. A tensioning device 50 is arranged in the region of the feed-through 62 of the screen tray 60, which tensioning device 50 can be used to adjust the screen tensioner 40 in a tensioning direction along the central transverse plane MQ.

[0056] The tensioning devices 50 each have a fixed support bearing 56 which is preferably securely connected (eg welded) to the end wall 61 .

[0057] The support bearing 56 can be designed such that it has a holder 57 to which at least one support 56.1 is connected, preferably in one piece. By means of the two supports 56.1 and the holder 57, the support bearing 56 can be firmly connected to the designated end wall 61. The tensioning device 50 also has a tensioning member 52, which engages behind the screen tensioner 40 in a form-fitting manner in order to move the screen tensioner 40 in the tensioning direction. Legs 51, 53 can be connected to (preferably molded to) opposite ends of the tensioning member 52.

[0058] Between the legs 51, 53 there is a mounting 54 for the screen tensioner 40. The leg 53 overlaps the top and the leg 51 overlaps the bottom of the screen tensioner 40, preventing the screen tensioner 40 from moving in these directions when it is tensioned.

[0059] At least one tensioning screw 58 is used to adjust the tensioning member 52 in the tensioning direction, by means of which the tensioning member 52 can be continuously adjusted. In doing so, the tensioning screw 58 rests against the holder 57. The tensioning member 52 can be continuously adjusted by means of a threaded connection.

[0060] In this exemplary embodiment, each of the legs 51 , 53 has a threaded mounting 55 . The holder 57 has two feed-throughs through which a tensioning screw 58 is inserted and screwed into the threaded mounting 55 .

[0061] Figure 4 and Figure 5 The assembly position of the screen tensioner 40 is shown in the untensioned position. If the tensioning screws 58 of the two tensioning devices 50 are then tightened, the first tensioning edge 42.1 is in the region of its contour center 49.2 with its maximum arc H and the base section 24.3 of the bend 24.2 (see Figure 4) meet. If the tensioning screw 58 is now tightened further, the screen lining 20 is tensioned starting from the profile center 49.2. This results in a reaction force of the screen lining 20, which acts on the screen tensioner 40. Due to this reaction force, the screen tensioner 40 bends so that the first clamping edge 42.1 moves continuously towards the two profile ends 49.1 on the base section 24.3. In this way, the tensioning force is gradually applied to the screen lining 20. Therefore, the convex curved profile of the first tensioning edge 42.1 ensures a uniform tensioning of the screen lining 20.

[0062] When the tensioning device 50 is tensioned, the tensioning member 52 moves in the tensioning direction. This ensures Figure 3 The fastening section 46 in FIG. 4 is offset from left to right along the slot-shaped feedthrough 62 .

[0063] The assembly process is complete once a sufficiently uniform tension has been created in the screen lining 20. Uniform tension can be estimated by sound testing at various points on the screen lining 20. For this purpose, the screen lining 20 is struck at various points. The tensioning state can be inferred from the sound produced.

[0064] The screen lining 20 is removed in the reverse order. To do this, first the tensioning screw 58 is loosened and the screen tensioner 40 can then be moved in the feed-through 62 until it no longer engages with the bend 24.2. The screen lining 20 can then be lifted upward and moved in the direction opposite to the tensioning direction so that the bend 23.2 no longer engages with the retaining lug 33 (see Figure 2 ) engagement. The screen liner 20 can then be lifted out of the screen tray 60 and replaced with a new screen liner 20.

[0065] If the second screen lining 20 is different from the first screen lining 20 and requires a different, in particular smaller, preload than the previously installed screen lining 20, the screen tensioner 40 can be adapted for this second screen lining 20 by merely rotating it so that the second tensioning edge 42.1 engages with the designated bend 24.2 of this screen lining 20. The screen tensioner 40 can then be clamped again to the new screen lining 20 in the same manner as described above.

[0066] In other words, the screen tensioner 40 may be used to optimally tension two different screen liners 20 .

[0067] In order to facilitate the user to correctly assign the required tensioning edges 42.1, 43.1 to the respective screen linings 20, an identification mark 48 may be provided in the region of at least one fastening section 46. Figure 4 Preferably, the identification mark 48 is incorporated into the longitudinal end of the fastening section 46.

Claims

1. A screen tensioner (40) for tensioning a screen lining (20) in a screening machine (10), the screen tensioner (40) having a rod-shaped or segmented tensioning section (41) which has a fastening section (46) in the region of each of its two longitudinal ends; Features: The tensioning section (41) has a first tensioning protrusion (42) in the area of ​​a first tensioning end and a second tensioning protrusion (43) on the opposite second tensioning end, the first tensioning protrusion forming a first tensioning edge (42.1), the second tensioning protrusion forming a second tensioning edge (43.1), the first tensioning edge (42.1) and the second tensioning edge (43.1) extending between two fastening sections (46), the first tensioning edge (42.1) forming a first tensioning contour and the second tensioning edge (43.1) forming a second tensioning contour, and the first tensioning contour and the second tensioning contour have different geometric shapes.

2. The screen tensioner according to claim 1, characterized in that: One of the two tensioning edges (42.1, 43.1) is convex with a curvature extending between the two fastening sections (46), and the other tensioning edge (43.1, 42.1) is convex or concave with a curvature extending between the two fastening sections (46), or the other tensioning edge (43.1, 42.1) extends in a straight line between the two fastening sections (46).

3. The screen tensioner according to claim 1 or 2, characterized in that: The tensioning profiles of the first tensioning edge (42.1) and the second tensioning edge (43.1) each have a profile end section (49.1) in the region of their ends facing the fastening section (46) and a profile center (49.2) between the profile end sections (49.1), the profile center (49.2) of at least one of the tensioning edges (42.1, 43.1) being offset relative to the profile end section (49.1) in the tensioning direction or counter to the tensioning direction at a maximum arc H when the tensioning edges (42.1, 43.1) are projected into the central transverse plane MQ; and the amount of the curvature H of the first tensioning edge (42.1) is different from the amount of the curvature H of the second tensioning edge (43.1); Alternatively, the projection of one tensioning edge (42.1, 43.1) into the central transverse plane MQ forms an arc H, and the projection of the other tensioning edge (42.1, 43.1) into the central transverse plane MQ forms a straight line.

4. The screen tensioner according to claim 3, characterized in that: The amount of arc H is less than or equal to 25 mm.

5. The screen tensioner according to claim 1 or 2, characterized in that: The tensioning section (41) has a top (44) and a bottom (45), and the screen tensioner (40) is designed symmetrically with respect to a central transverse plane MQ extending between the top (44) and the bottom (45), at least in the region of its tensioning section (41).

6. The screen tensioner according to claim 1 or 2, characterized in that: The first tensioning edge (42.1) and / or the second tensioning edge (43.1) have a rounded corner extending between the top and the bottom of the tensioning section (41).

7. The screen tensioner according to claim 1 or 2, characterized in that: At least one fastening section (46) has at least one identification mark (48) which is assigned to the first clamping end and / or the second clamping end.

8. The screen tensioner according to claim 1 or 2, characterized in that: The convex or concave tensioning edge (42.1, 43.1) is circular or elliptical in shape or consists of several contour segments, and / or the tensioning edge (42.1, 43.1) follows a continuously differentiable function in the direction between the two fastening segments (46).

9. The screen tensioner according to claim 7, characterized in that: The identification mark (48) is designed as a recess.

10. The screen tensioner according to claim 7, characterized in that: The identification mark (48) is incorporated into a longitudinal end of the fastening section (46).

11. A screening machine (10), characterized in that: A screen arrangement is provided, which has a screen lining (20), wherein a screen tensioner (40) according to any one of claims 1 to 10 acts on the screen lining (20).

12. The screening machine (10) according to claim 11, characterized in that The screen lining (20) has a fastening edge (23, 24) at at least one of its longitudinal ends, which is designed in the form of a bend (23.2, 24.2) and one of the tensioning protrusions (42, 43) of the screen tensioner (40) engages with the bend (23.2, 24.2).

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