AU2004235827B2 - A screening panel and screening assembly including the panel - Google Patents

Description

WO 2004/098798 PCT/AU2004/000499 "A screening panel and screening assembly including the panel" Field of the Invention This invention relates to the screening of materials. More particularly, the 5 invention relates to a screening panel for use in a screening assembly which screens material to classify or sort the material. The invention also relates to a screening assembly including the screening panel. Background to the invention 10 Screening arrangements are used widely in the mining industry, particularly the coal mining industry, for the screening or classifying of ores and slurries. Material is passed over a vibratory screen deck. Apertures of screening panels arranged on the deck pass material having dimensions smaller than screening apertures of the screen panels while materials having dimensions larger than those of the screening apertures 15 are retained on a top surface of, and traverse, the panels of the screen deck for further processing. The greater the screening surface area which can be achieved, the higher the efficiency of the screen deck, However, the screening panels are generally of a plastics material and need to be supported so that distortion of the screening apertures does not 20 occur thereby allowing fines greater than a predetermined size to pass through the screening panels. There is therefore a trade off between screen surface area and screening panel rigidity. Summary of the Invention 25 According to a first aspect of the invention, there is provided a screening panel, which includes: a body member having a pair of opposed, parallel side members and a pair of opposed, parallel edges arranged transversely to the side members; a plurality of spaced, parallel intermediate members interconnecting the side 30 members; an attaching formation defined by each of at least certain of the intermediate members; and a plurality of spaced, parallel slot-defining members supported on the intermediate members and extending parallel to the side members, the slot defining 35 members defining, between each adjacent pair of slot defining members or a slot- WO 2004/098798 PCT/AU2004/000499 2 defining member and an adjacent side member, a screening slot, each screening slot terminating at at least one of the edges of the body member. It will therefore be appreciated that each screening slot has a length dimension which is the same as that of each side member so that, in use,. when screening panels 5 are arranged in edge-to-edge abutment, a screen deck is formed having a continuous slot along the length (in a direction of flow of material) of the screen deck. In this specification, the terminology is used that a "side" member or element of the screening panel or a support frame for the screening panel, as the case may be, extends in a direction parallel to a direction of flow of the material over the screen 10 deck, Generally, a screening assembly, comprising a screening panel mounted on its associated support frame, is rectangular in shape and the shorter sides and, hence, the slots, are parallel to a direction of flow of material. However, in certain circumstances, a cross-flow configuration may be used where the screening panel is configured so that the slots extend parallel to the longer sides. In such a cross-flow arrangement the 15 shorter sides of the screening panel would remain parallel to a direction of flow of material. The body member and slot-defining members may be formed integrally as a one-piece moulding. Preferably, the screening panel is formed by a moulding process of a plastics material, such as a polyurethane material. The screening panel may be 20 without any reinforcing. Preferably, each intermediate member defines an attaching formation. Each attaching formation may be a groove defined in an operatively under surface of the intermediate members, the groove extending substantially the full length of each intermediate member. A mouth of each groove may have a constriction to facilitate 25 clipping engagement with an attachment formation of an underlying support frame. An operatively bottom surface of each intermediate member may lie substantially flush with an operatively bottom surface of each slot-defining member. Outermost intermediate members of the body member may lie inwardly of the edges of the panel to facilitate attachment of the screening panel to, and its removal 30 from, the support frame. Optionally, the side members may also carry attaching formations. The attaching formations on the side members may, once again, be in the form of grooves extending parallel to the side members. Each groove in the side member may also have a constricted mouth to facilitate clipping engagement with the attachment formations of 35 the support frame.

WO 2004/098798 PCT/AU2004/000499 3 According to a second aspect of the invention, there is provided a screening assembly support frame which includes: a body structure defining a pair of opposed, parallel side elements; a plurality of spaced, parallel transverse elements interconnecting the side 5 elements; and an attachment formation carried on an operatively upper surface of each of at least certain of the transverse elements for attaching a screening panel, as described above, to the body structure. Preferably, the body structure, the transverse elements and the attachment 10 formations are formed integrally, as a one piece unit, by a moulding process. Preferably, the support frame is formed by a moulding process of a plastics material, such as a polyurethane material. Preferably, each of the transverse elements carries an attachment .formation. Each attachment formation may be in the form of a rib extending substantially the full 15 length of each transverse element. The rib may have a waisted region where it joins its underlying transverse element to facilitate clipping engagement with the attaching formation of an associated intermediate member of the screening panel. Optionally, the side elements may also carry attachment formations in the form of ribs extending along top surfaces of the side elements. 20 The body structure may include a central element extending parallel to the side elements. The central element may underlie the transverse elements. At least the~ side elements may include reinforcing for imparting rigidity to the support frame. The transverse elements may also carry reinforcing. The reinforcing may be metal strips or bars. 25 The side elements may define engaging elements for engaging underlying formations of a screen deck. The engaging elements may be in the form of clips defined in the side elements. The clips may clip into underlying rails on the screen deck. As is the case with the screening panel, outermost transverse elements may be 30 arranged inwardly of edges of the side elements to be engaged by their associated intermediate members of the screening panel. According to a third aspect of the invention, there is provided a screening assembly which includes: at least one screening panel, as described above; and 35 at least one support frame, as described above, to which the at least one screening panel is releasably attached.

WO 2004/098798 PCT/AU2004/000499 4 The assembly may include a plurality of rails which are, in use, secured to a screen deck with the at least one support frame releasably engaging the rails. In one embodiment of the invention, the assembly may include a securing system, described in greater detail in the Applicant's co-pending International Patent 5 Application No. PCT/AU02/01668, by means of which the screening assemblies are removably secured to the rails. The contents of the International Patent Application are incorporated herein by reference. The rails may have deflection guards secured to operatively lower surfaces thereof for deflecting material passing through the screening panels away from the rails 10 and inhibiting the ingress of detritus into the rails. Brief Description of the Drawings Embodiments of the invention are now described, by way of example, with reference to the accompanying drawings in which: 15 Figure 1 shows a plan view of four screening assemblies in accordance with an aspect of the invention; Figure 2 shows a side view of the assemblies of Figure 1; Figure 3 shows an end view of the assemblies; Figure 4 shows a plan view of a variation of the assemblies; 20 Figure 5 shows a side view of the variation of the assemblies; Figure 6 shows a plan view of a support frame, in accordance with another aspect of one embodiment of the invention; Figure 7 shows an exploded side view of a screening assembly, including the frame of Figure 6; 25 Figure 8 shows an exploded end view of the assembly of Figure 7; Figure 9 shows a plan view of a support frame, in accordance with said another aspect of one embodiment of the invention; Figure 10 shows an exploded side view of an assembly including the frame of Figure 9; 30 Figure 11 shows an exploded end view of the assembly of Figure 10; Figure 12 shows a side view of a part of one of the assemblies of Figures 1 to 3; Figure 13 shows, on an enlarged scale, the encircled portion of Figure 12; and Figure 14 shows a side view of yet a further variation of a part of the assemblies of Figures I to 5.

WO 2004/098798 PCT/AU2004/000499 5 Detailed Description of the Drawings In the drawings, reference numeral 10 generally .designates a screening assembly, in accordance with a first embodiment of the invention. More particularly, in Figures 1-3 of the drawings, a combination of four assemblies -10, each in 5 accordance with the first embodiment of the invention, is illustrated. Each assembly 10 includes a screening panel 12 removable attached to a support frame 14. Each panel 12, which is also referred to in the trade as a cloth, is a peel-off panel 12 to be removable relative to its underlying support frame 14. 10 Each panel 12 includes a pair of opposed side members 16. A plurality of slot defining members 18 extend parallel to the side members 16 so that slots 20 are forced between adjacent pairs of slot-defining members 18 or a slot-defining member 18 and a side 16 in the case of the endmost slot-defining members 18. The slot-defining members 18 are supported on intermediate members 22 15 (shown in greater detail in Figures 12 and 13 of the drawings). The intermediate members 22 extend transversely to the side members 16 and, more particularly, at right angles to the side members 16. Each intermediate member 22 defines an attaching formation in the form of an attaching groove 24 extending substantially along its length. The groove 24 has a constricted mouth 26 to facilitate 20 clipping engagement with a rib 28 arranged on an upper part 30 of an underlying transverse element 50 of the support frame 14, as will be described in greater detail below. Importantly, as indicated in Figure 1 of the drawings, the slot-defining members 18 and, accordingly, the slots 20, run the full length of the panel 12. The length of the 25 panel 12 is the dimension of the panel parallel to a direction of flow of material over the assemblies 10 as indicated by the arrow 32 in Figure 1 of the drawings. In other words, each slot-defining member 18 terminates at opposed edges 34 of the panel 12, the edges 34 being at right angles to the sides 16 of the panel 12. As a result, when a plurality of the assemblies 10 are secured to a screen deck, as shown by the four 30 assemblies 10 in Figure 1 of the drawings, the slot-defining members 18 of adjacent panels 12, in the direction of flow 32 of material, are aligned to form continuous slots 20 in an upper surface of a screen deck. The panel 12 is a one-piece moulding of a suitable synthetics plastics material. Typically, the panel 12 is of a polyurethane material. The polyurethane material is of 35 sufficient hardness so that, together with the lattice-like construction created by the WO 2004/098798 PCT/AU2004/000499 6 slot-defining members 18 and the transverse members 22, it provides sufficient rigidity for screening purposes. Typically, the panel 12 has a Shore Hardness of 95A. Also shown in Figures 1-5 and Figure 12 of the drawings is a rail 36 by means of which the assemblies 10 are secured to an underlying structure (not shown) of the 5 screen deck. The rail 36 has a plurality of clips 38 (one of which-is shown in Figure 12 of the drawings) standing proud of the rail 36. The clips 38 project above an upper surface of the panels 12 and a securing element 40 is secured to the clips 38 by being applied in a direction of arrow 42 (Figure 2) to retain the assemblies 10, in use, on the rails 36. The securing arrangement is described in greater detail in the above 10 referenced International Patent Application. Referring to Figure 14 of the drawings, a variation of the embodiment of Figures 1-5 is shown. In the Applicant's above referenced International Patent application it is described that the securing element 40 slides over the top surface of the panel to engage the clips 38, the clips 38 being received in slots 39 opening out into a side of the 15 element 40. In the illustrated variation, the securing element 40 has a pair-of opposed rebates or recesses 41 formed in its underside. Each recess 41 is dimensioned snugly to accommodate an edge of the panel 12. With this arrangement, when a new panel 12 -is attached to its underlying frame 14, the edge of the panel 12 is slipped into the recess 41 and the panel 12 is then clipped to its frame 14. As a result, the securing element 40 20 need not first be removed which results in time-savings and, consequently, reduced down time of the deck. Therefore the economic viability of the deck is improved. It will, however, be appreciated that, when the securing element 40 is to be removed, which happens far more infrequently than the need to replace panels 12, the panel 12 at a release side of the element 40 (ie. panel 12.1 in Figure 14) needs first to be removed. 25 It is to be noted that, in the -embodiment shown in Figures 4 and 5 of the drawings, a deflection guard 44 is arranged beneath the rail 36 and beneath the assemblies 10 to deflect detritus from the rail 36, in use. Each frame 14 has a pair of opposed, parallel side elements 46. Each side element 46 defines an engaging element in the form of a clip 48 for clipping attachment 30 to one of the rails 36. A plurality of transverse elements 50 (shown most clearly in Figures 6 to 10 of the drawings), span the gap between the side elements 46 of the frame 14. Each transverse element 50 includes the waisted, upper part 30 that defines the rib 28 which clips into the groove 24 of its associated intermediate member 22 of the panel 12 for 35 securing the panel 12 to the frame 14.

WO 2004/098798 PCT/AU2004/000499 7 In the embodiments illustrated in Figures 6 to 11 of the drawings, the means by which the frames 14 are secured to the rail 36 differs from that in Figures 1-3 and 12 of the drawings. In theses embodiments, the frames 14 are merely clipped to the rails in accordance with the teachings of the Applicant's Australian Patent No. 627919 without 5 the use of any positive locking arrangements. The contents of Australian Patent No. 627919 are incorporated herein by reference. Further, in the embodiment shown Figures 6 to 8 of the drawings, the ribs 28 run almost the full width of the frame 14 and overlie the side elements 46. In the embodiment shown in Figures 9 to 11 of the drawings, each side member 46 carries a 10 rib 52 extending along its length (once again, in the direction of flow 32) of material and the ribs 28 of the transverse elements 50 terminate at the side elements 46. In the embodiment shown in Figures 9 to 11 of the drawings, the panel 12 has grooves 54 defined in its side members 16 in which the ribs 52 of the frame 14 are receivable. The endmost transverse elements 50 of the frame 14. and their 'associated 15 intermediate members 22 of the panels 12 lie inwardly of edges of the panel 12. This facilitates removal of the panels 12 from their associated frames 14, in use. The transverse elements 50 of the frame 14 carry reinforcing bars 56. The side elements 46 of the frame 14 also carry reinforcing elements 58. The reinforcing bars 56 and the reinforcing elements 58 are embedded in the frame 14 and assist in 20 providing the requisite rigidity for the assemblies 10. Each frame 14 is a moulded, one-piece unit. The frames 14 are typically moulded from a plastics material such as polyurethane. Each frame 14 can have the same Shore Hardness as its associated panel 12 or can be of a softer material, for example, having a Shore Hardness of 93A. 25 In use, as described above, the panels 12 are clipped on to the frames 14 by means of clipping engagement of the grooves 24 and ribs 28 of the panels 12 and frames 14, respectively. This arrangement facilitates removal of the panels 12, for example, once they have worn out, from their associated frames. 14 for replacement purposes. 30 The slots 20 defined in each panel 12 run to edges 34 of the panels 12 to form continuous slots in the screen deck in the direction of flow 32 of material over the screen deck. Typically, with present screening panels of which the Applicant is aware, and assuming a slot width of approximately 0.5mm, about 9% of a surface area of a 35 screening panel is open, ie, defined by slots or other apertures due to transverse members of screening assemblies creating blind or non-apertured areas. With the WO 2004/098798 PCT/AU2004/000499 8 provision of slots 20 running to the edges 34 of the panels 12, in accordance with the invention, approximately 12% of the panel 12 is open. Thus, an increase in open area of over 30% is obtained in comparison with conventional screening panels of which the Applicant is aware. Hence, the screening efficiency of a screen deck using: the 5 assemblies 10 of the invention is greatly improved. The assemblies 10 still have the required rigidity due to the reinforcing in the frames 14 and the use of the lattice-like construction of the slot-defining members 18 and transversely, extending intermediate members 22 of the panels 12. It will be appreciated by persons skilled in the art that numerous variations 10 and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly. described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims (25)

1. A screening panel, which includes: a body member having a pair of opposed, parallel side members and a pair of opposed, parallel edges arranged transversely to the side members; 5 a plurality of spaced, parallel intermediate members interconnecting the side members; an attaching formation defined by each of at least certain of the intermediate members; and a plurality of spaced, parallel slot-defining members supported on the 10 intermediate members and extending parallel to the side members, the slot defining members defining, between each adjacent pair of slot defining members: or a slot defining member and an adjacent side member, a screening slot, each screening slot terminating at at least one of the edges of the body member. 15

2. A screening panel as claimed in claim 1 in which the screening slot has a length dimension which is the same as that of a side member.

3. A screening panel as claimed in claim 1 or claim 2 in which the body member is rectangular in shape with the side members being shorter sides of the rectangle, the 20 shorter sides, in use, being arranged parallel to a direction of flow of the material over the screen deck.

4. A screening panel as claimed in any one of the preceding claims in which the body member, the intermediate members and the slot defining members are formed 25 integrally as a one-piece moulding.

5. A screening panel as claimed in any one of the preceding claims which is formed by a moulding process of a plastics material. 30

6. A screening panel as claimed in any one of the preceding claims in which each attaching formation is a groove defined in an operatively under surface of its associated intermediate member.

7. A screening panel as claimed in claim 6 in which a mouth of each groove has a 35 constriction to facilitate clipping engagement with an attachment formation of an underlying support frame. 10

8. A screening panel as claimed in any one of the preceding claims in which an operatively bottom surface of each intermediate member lies substantially flush with an operatively bottom surface of each slot-defining member. 5

9. A screening panel as claimed in any one of the preceding claims in which outermost intermediate members lie inwardly of the edges of the body member.

10. A screening panel as claimed in any one of the preceding claims in which each side member carries an attaching formation. 10

11. A screening assembly which includes: at least one screening panel, as claimed in claims 1 to 10; and at least one screening assembly support frame which includes: a body structure defining a pair of opposed, parallel side elements; 15 a plurality of spaced, parallel transverse elements interconnecting the side elements; and an attachment formation carried on an operatively upper surface of each of at least certain of the transverse elements for attaching the screening panel. 20

12. A screening assembly as claimed in claim 11 in which the body structure of the support frame, the transverse elements of the support frame and the attachment formations of the support frame are formed integrally as a one piece moulding.

13. A screening assembly as claimed in claim 11 or claim 12 in which the support 25 frame is formed by a moulding process of a plastics material.

14. A screening assembly as claimed in any one of claims 11 to 13 in which each of the transverse elements of the support frame carries an attachment formation. 30

15. A screening assembly as claimed in claim 14 in which each attachment formation of the support frame is a rib extending substantially the full length of each transverse element of the support frame.

16. A screening assembly as claimed in claim 14 or claim 15 in which each rib of 35 the support frame has a waisted region where it joins its underlying support frame 940976_ .doc 11 transverse element to facilitate clipping engagement with the attaching formation of an associated intermediate member of the screening panel.

17. A screening assembly as claimed in any one of claims 11 to 16 in which the side 5 elements of the support frame carry attachment formations.

18. A screening assembly as claimed in any one of claims 11 to 17 in which the body structure of the support frame includes a central element extending parallel to the side elements of the support frame. 10

19. A screening assembly as claimed in any one of claims 11 to 18 in which the side elements of the support frame include reinforcing.

20. A screening assembly as claimed in any one of claims 11 to 19 in which the side 15 elements of the support frame define engaging elements for engaging underlying formations of a screen deck.

21. A screening assembly as claimed in any one of claims 11 to 20 in which outermost transverse elements of the support frame arc arranged inwardly of edges of 20 the side elements of the support frame.

22. A screening assembly as claimed in any one of claims 11 to 21 which includes a plurality of rails secured to a screen deck with the at least one support frame releasably engaging the rails. 25

23. A screening assembly as claimed in claim 22 in which each rail has a defl'ecting guard.

24. A screening panel substantially as hereinbefore described with reference to any 30 one embodiment, as that embodiment is shown in the accompanying drawings.

25. A screening assembly substantially as hereinbefore described with reference to any one embodiment, as that embodiment is shown in the accompanying drawings. 35 940976_1.doc