AU9698698A - Screening assembly - Google Patents

Description

S F Ref: 440410

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

4 t

I

I

c 4 t 4 44 4 4 4 4 4 I 4 4 Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Cyber Technics Pty Ltd 11 Welwyn Close Buttaba New South Wales 2283

AUSTRALIA

Scott Allan Taylor Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Screening Assembly ASSOCIATED PROVISIONAL APPLICATION

DETAILS

131] Application No(s) [33] Country PP0777

AU

PP2833

AU

[32] Application Date 8 December 1997 6 April 1998 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815 SCREENING

ASSEMBLY

Technical Field The present invention relates to screening machines and, in particular, to screening assembly including a screening module for a screening machine.

Background of the Invention Coal and other particulates are often classified by particle size before further processing. Vibrating machines having screening meshes are used to separate larger from smaller particles. Previously, screening machines utilised woven wire meshes which suffered from a number of disadvantages. For example, the weight of the material being screened caused the wire meshes to stretch. Therefore, tensioning of the mesh was required on a regular basis. Further, changing the mesh size of the screens on these machines would entail the complete removal of the screen. Attempts have been made to create screening meshes for screening machines which are quick and easy to change, and relatively strong and rigid so as to minimise stretching. Numerous modular screen systems have been developed with the aim of overcoming these problems, but these 4*44 systems have sometimes failed to achieve their goal and/or have created problems of their own.

Some screen modules rely on an interference fit between adjacent modules and/or S between the module and vertical flanges provided on attachment rails secured to the S 20 machine frame to maintain them in position on the machine frame, with each module having to be hammered along its edges to jam it into position against the neighbouring module flange and a lever being required to remove the modules. Apart from the difficulty in inserting and removing the modules, they have a tendency to "pop" out of position under some operating conditions due particularly to the vibration loads applied to the machine frame.

Screening systems have also been proposed which rely on pins being secured in holes provided in the machine frame, however these systems are not readily retrofittable, require hammers and special extraction tools to secure and release the pins from the [n:\lib11]02266:GJG holes. Pin systems are also subject to shear failure of the pin at the interface with the hole edge.

Another pin system relies on a series of pins each to be driven through a bore defined between two opposing lugs of adjacent screen modules which protrude through a common hole provided in the sub-frame. Driving the pin into the bore flares the lugs outwardly beneath the hole, bending the lugs about the edge of the hole, and thereby prevent the lugs from passing back through the hole, locking the modules to the subframe. This system is also subject to shear failure of the lugs and the adjacent modules can readily pop out prior to the fixing pins being driven in.

Object of the Invention It is the object of the present invention to overcome or substantially ameliorate at least some of the above disadvantages.

,Summary of the Invention The present invention in one broad form provides a screening assembly for a (4 15 screening machine comprising: a screen module including: a screen module body having laterally extending ends and longitudinally extending sides bordering a screen region; and a resiliently deflectable, laterally extending and downwardly projecting module end flange disposed at a said module body end, said module end flange having an S outwardly facing flange surface defining an obtuse included angle with an adjacent upper surface of said module body, said module end flange further having an inwardly facing Sflange surface defining a downwardly opening recess with an outwardly facing surface of said module body end; S4 25 said screening assembly further comprising: a laterally extending attachment rail having a laterally extending attachment rail base adapted to be fixed to, or integrally formed with, a screening machine frame member, said attachment rail further having a laterally extending attachment rail flange projecting upwardly from said base at an acute angle, said screen module being locatable [n:\lib11]02266:GJG on said attachment rail with said attachment rail flange received in said recess and said attachment rail flange projecting upwardly and outwardly with respect to said screen module body; and, a locking member adapted to engage said outwardly facing flange surface following location of said screen module on said attachment rail so as to deflect said module end flange to bring said inwardly facing flange surface into bearing engagement with said attachment rail flange, thereby wedging said module end flange in a locked position between said locking member and said attachment rail flange.

Typically, said flange inwardly facing surface is disposed substantially at right angles to said module body upper surface.

Said attachment rail flange may project upwardly from said base at an angle of approximately 600.

Preferably, said outwardly facing flange surface has at least one groove or projection adapted to engage a corresponding projection or groove provided on said locking member.

Preferably, said recess substantially encases said attachment rail flange when said module end flange is in said locked position.

Preferably, said attachment rail is provided with two said attachment rail flanges, each said attachment rail flange projecting upwardly from said base toward the other said attachment rail flange, said screening assembly being provided with two adjacent said screen modules locatable on said attachment rail with said attachment rail flanges each being received in the said recess of the respective said screen module, said locking member being adapted to engage the said outwardly facing flange surface of both said screen modules to wedge both said module end flanges into their locked positions.

25 Typically, said attachment rail is adapted to be fixed to said screening machine frame member and includes two laterally extending and downwardly projecting locating flanges for locating said attachment rail on said frame member.

Preferably, said attachment rail is formed of plastics material internally reinforced with a rigid member.

[n:\libll]02266:GJG Preferably, said locking means comprises an elongate strip adapted to engage said outwardly facing flange surfaces of said adjacent screen modules and deform said module end flanges into said locked positions.

Typically, said locking member further comprises a head adapted to extend onto each said module body upper surface, thereby covering the interfaces between said elongate strip and each said module end flange outwardly facing surface.

Preferably, said module body upper surface of each said adjacent screen module has at least one groove or projection adapted to engage a corresponding projection or groove provided on an underside of said head.

In one embodiment, the locking member is in the form of a cam key having a generally elliptical form adapted to be inserted between said outwardly facing flange surfaces of said adjacent screen modules, and rotated so as to engage said outwardly facing flange surfaces and thereby deform said module end flanges into said locked positions wedged between said locking member and a said attachment rail flange.

Said screen module may be provided with two said module end flanges, a said S module end flange being provided at each of said module body ends, said screening assembly being provided with two spaced said attachment rails each associated with a said module end flange.

Preferably, each said screen module is provided with a longitudinally extending side reinforcement member disposed adjacent each said side of said module body, opposing ends of each said side reinforcement member extending to adjacent respective ends of said screen module, said attachment rail flanges being provided with notches for receiving S respective said side reinforcing member ends such that, in use, said side reinforcing members are supported by said attachment rails.

25 Preferably, each lateral end of each said module end flange lies between said side reinforcement members, said ends of said module end flanges being separated from said side reinforcement members so as to enable independent deflection of said module end flanges.

Typically, said ends of said side reinforcement members are encased in longitudinal extension portions of said module body, said extension portions being received in [n:\libll]02266:GJG respective said notches of said attachment rail flange and separated from said ends of said module end flanges.

Preferably, each said side reinforcement member is formed as a substantially vertical plate.

Each said screen module may be provided with a laterally extending end reinforcement member disposed in each said module end flange.

Preferably, each said end reinforcement member is formed as a bar.

In another broad form the present invention provides a locking member for locking adjacent screen modules to an attachment rail in a screening machine, said screen modules having resiliently deflectable laterally extending and downwardly projecting module end flanges located at adjacent ends engageable with laterally extending attachment rail flanges provided on said attachment rail, said locking member being in the form of a cam key having a generally elliptical form adapted to be inserted between said module ends S flanges, and rotated so as to engage said module end flanges and thereby deflect said module end flanges into locked positions wedged between said locking member and a said attachment rail flange.

In a further broad form the present invention provides a screening assembly for a screening machine comprising: a screen module including: a screen module body having laterally extending ends and longitudinally extending sides bordering a screen region; and a resiliently deflectable, laterally extending and downwardly projecting module end flange disposed at a said module body end, said screening assembly further comprising: a laterally extending attachment rail having a laterally extending attachment rail base adapted to be fixed to, or integrally formed with, a screening machine frame member, said attachment rail further having a laterally extending attachment rail flange projecting upwardly from said base, said screen module being locatable on said attachment rail with said attachment rail flange received in said recess, and, [n:\libll]02266:GJG a locking member adapted to engage said module end flange following location of said screen module on said attachment rail so as to wedge said module end flange in a locked position between said locking member and said attachment rail flange, wherein said screen module is provided with a longitudinally extending side reinforcement member disposed adjacent each said side of said module body, opposing ends of each said side reinforcement member extending to adjacent respective ends of said screen module, said attachment rail flange being provided with notches for receiving respective said side reinforcing member ends such that, in use, said side reinforcing members are supported by said attachment rails.

Typically each lateral end of said module end flange lies between said side reinforcement members, said ends of said module end flanges being separated from said side reinforcement members so as to enable independent deflection of said module end flanges.

'Preferably said ends of said side reinforcement members are encased in longitudinal extension portions of said module body, said extension portions being received in S respective said notches of said attachment rail and separated from said ends of said module end flanges.

Preferably, each said side reinforcement member is formed as a substantially vertical plate.

S 20 Brief Description of the Drawings 4Preferred forms of the present invention will now be described by way of S example with reference to the accompanying drawings wherein: Figure 1 is a plan view of a screen module.

Figure 2 is an inverse plan view of the screen module of Figure 1.

Figure 3 is a plan view of a screening assembly including four screen modules.

Figure 4 is a plan view of the screening assembly of Figure 3 with the screen modules in a partly assembled unlocked state.

Figure 5 is a partial cross section of a partly assembled screening assembly.

Figure 6 is a partial cross section of an assembled screening assembly.

[n:\libll]02266:GJG ~111111~ Figure 7 is a partial cross section of a partly assembled screening assembly with an alternative locking member, in its unlocked state.

Figure 8 is a partial cross section of an assembled alternate screening assembly.

Figure 9 is an isometric view of a typical attachment rail.

Figure 10 is a partial side elevation view of a partly assembled screening assembly.

Figure 11 is a partial side elevation view of the screening assembly of Figure when assembled.

Figure 12 is a partial cross section of an assembled screening assembly.

Figure 13 is a partial cross section of screen module when attached to the side of a screening machine.

Figures 14a 14c are partial side elevation views of a screening assembly including the alternative locking member of Figure 7 in the progressive phases of locking.

Detailed Description of the Preferred Embodiments Figures 1 and 2 are plan and inverse plan views of a screen module 1. Figure 3 4,4, depicts a screen assembly including four of the screen modules 1 locked onto the frame 4 (not shown) of an existing screening machine, whilst Figure 4 depicts the screen modules located on the screening machine but in an unlocked position. The screen modules 1 are preferably made from a urethane material. The screen modules 1 each have a screen module body with laterally extending ends and longitudinally extending sides bordering a S screen region (not shown) which may have different sized meshes depending on the desired application. For example, the screen region may have large holes or may be used as a weir without holes at all. Further, the "screen region" may be fitted with other equipment such as flow deflectors. It is preferred that the screen region is substantially 25 flat, however there may be applications where the screen region is curved. The surface of the screen region may be made of polyurethane and/or rubbers of various durometers and properties, ceramic tiles cast in urethane, stainless steel wedge wire and perforated steel plate, depending on the application.

[n:\lib11]02266:GJG Reinforcement members 7a and 7b typically extend along the ends and sides, respectively, of the screen module body. Further central laterally extending reinforcement members 7c may be provided at predetermined spacings between the end reinforcement members 7a. A central longitudinally extending reinforcement member 7d may be positioned between the side reinforcement members 7b. The various reinforcement members are not depicted in hidden detail in Figure 4 for clarity purposes.

As depicted in Figure 5, at least one end of the screen module 1 is provided with a resiliently deflectable, laterally extending and downwardly projecting module end flange 16. The module end flange 16 has an outwardly facing flange surface 9 which protrudes downwardly and outwardly with respect to the screen region such that it defines an obtuse included angle with the adjacent upper surface of the module body. The module end flange 16 is cantilevered to the end of the module body. The module end flange 16 has an inwardly facing flange surface 24 which defines a downwardly opening recess 21 with an outwardly facing surface 25 of the module body end.

The module end flange 16 may extend laterally along substantially the entire end of the module body, ending short of the module body sides to allow for the side reinforcement members 7b to extend to adjacent the end of the screen module. In the preferred embodiment depicted, the flange 16 is interrupted midway along the end of the screen module to allow for the central longitudinally extending reinforcement member 7d, thus forming two separate flange portions arranged along the end of the module body.

A laterally extending attachment rail 3 having a laterally extending base is fixed to, or integrally formed with a laterally extending frame member 2 of the screening machine.

Attachment rails 3 are typically bolted in various locations to the laterally extending frame members 2. The attachment rail 3 has a laterally extending attachment rail flange projecting upwardly from the base 5 at an acute angle, which is here approximately 600.

Screen modules to be positioned in the central area of the screening machine away form the machine edges will typically be provided with a module end flange 16 at each end of the module body, with the end flanges 16 of longitudinally adjacent screen modules being locked onto a common attachment rail 3 with a common locking member 10. Such [n:\libIl]02266:GJG an attachment rail 3 is provided with two attachment rail flanges 5, each projecting upwardly toward the opposing flange.

Figures 4 and 5 depict longitudinally adjacent screen modules 1 located on a common attachment rail 3 prior to locking. The attachment rail flanges 5 are each received in the recess 21 of the corresponding screen module 1. The module end flange inwardly facing flange surface 24 is typically disposed substantially at right angles to the module body upper surface when the flange is in the undeflected state such that the module end flange 16 can be located over the attachment rail flange without the application of excessive force as is required of typical prior art screening assemblies.

When each end of the screen module 1 is provided with a module end flange 16, with each end being located on an attachment rail 3, the module end flanges 16 and attachment rails 3 are spaced such that the module 1 can be located onto the attachment rails 3 with the upper end 5a of the attachment rail flanges 5 received in the top of the recesses 21. In the preferred embodiment with the inwardly facing flange surface 24 oriented at right angles to the module body upper surface, the lower edge 24a of the inwardly facing flange surface 24 will lightly contact the upper end 5a of the corresponding attachment rail flange 5 when the screen module 1 is placed in position onto the attachment rails 5. The inwardly facing flange surface 24 will then slide along the upper end 5a of the rail flange 5 until the module is located in position. The module can thus be accurately located in position without the need for excessive force. The absence of any interference fit at the locating stage prevents the module from popping out prior to locking.

Rather than having the inwardly facing flange surface 24 at right angles to the module body upper surface, the inwardly facing flange surface 24 could be inclined S 25 outwardly such that the lower edge 24a did not contact the attachment rail flange during the locating process.

Alternatively, the inwardly facing flange surface 24 could be inclined slightly inwardly by a few degrees such that the lower edge 24a lightly engages the attachment rail flange upper end 5a, requiring light downward pressure, typically applied with an operators hand or foot, to deflect the module end flanges 16 outwardly to ride over the [n:\libl]02266:GJG attachment rail flange upper end 5a and snap into position adjacent the attachment rail flanges 5. Whilst some prior art screening modules require a large force to locate the module into position, which position is the same as the locked position, with that locating force being proportional to the maximum force the assembly can withstand without failure or disconnection of the module, the force used to locate the current screen module has no bearing on the service loads the assembly can successfully withstand.

Once located on the attachment rail 3 and prior to locking, the adjacent screen modules 1 will typically not touch, as depicted in Figure 5, or may lightly bear against each other as depicted in Figure 4, thereby avoiding any large loads needing to be applied to achieve an interference fit in positioning the modules 1, as is required in some prior art systems. When the screen modules 1 are located into position, a clearance 18 is defined between the module end flange inwardly facing flange surface 24 and the rail attachment flange 5, providing room for the necessary deflection of the module end flange 16 during S locking with the locking member To lock the screen module 1 into place, the flange outwardly facing surface 9 is engaged by a locking member 10 to deflect the module end flange 16 into a locked position (as depicted in Figure 6) wedged between the locking member 10 and the attachment rail flange 5. With the module end flange inwardly facing flange surface 24 bearing against the sloped surface of the attachment rail flange 5, a component of the bearing force locking the module end flange 16 onto the attachment rail flange 5 acts S4. vertically downwardly to positively hold the screen module 1 down rather then relying on vertical frictional forces as do some prior art interference fitting systems.

The bearing force locking the module end flange 16 acts over an extended lateral distance and over the height of the module end flange inwardly facing flange surface 24 to 25 reduce the bearing stresses on the module end flange 16 and attachment rail flange enabling the locking mechanism to withstand large service loads. Shear forces acting on the module end flange 16, which can result in failure of pin and lug type prior art systems and other known contoured flange systems, also act over a large area so as to reduce the shear stress levels for a given service load. The upper end 5a of the rail attachment flange is preferably smoothly contoured so as to reduce any possible stress concentrations.

[n:\libll]02266:GJG 11 The module end flange 16 is preferably resiliently compressible, made from a material such as polyurethane or rubber, such that it is compressed by the wedging force, thereby helping prevent loosening of the locking relationship and helping create a self sealing system. The end flanges 16 can also be strengthened with materials such as ceramic particles or fibreglass fibres. The modules can be readily unlocked by removing the locking member 10, allowing the screen modules 1 to be simply lifted out of position.

The end flange outwardly facing surface 9 is preferably provided with one or more grooves 17 which engage corresponding projections 29 provided on the engaging surface of the locking member 10, thereby helping maintain the locking member 10 in locking engagement with the module end flange 16, preventing any possible tendency for the locking member 10 to pop out of engagement. Alternatively the end outwardly facing surfaces 9 could be provided with projections and the locking member provided with corresponding grooves.

The recess 21 defined by the module end flange inwardly facing surface 24 and the outwardly facing surface 25 of the module body end preferably substantially encases the rail attachment flange 5 when the module end flange is in the locked position as depicted in Figure 6. The screen module 1 thus bears against both sides of the attachment rail flange 5, increasing the rigidity of the connection between the module 1 and attachment rail 3. The module body end outwardly facing surface 25, need not, however, bear against the attachment rail flange 5. Having a recess 21 protruding into the thickness of the screen module 1 for receiving the attachment rail flange 5 and to define the module end flange 16 helps keep the installation to a minimal thickness, rather than having the flange depend from the bottom of the screen module 1 which will increase the thickness of the installation.

The preferred locking member is formed as a laterally extending strip 10 which may extend up to the width of the screening machine frame to lock down several screen modules positioned side by side, or may be shorter in length such that each locking strip only extends across one module 1. The locking strip 10 will typically need to be hammered into position inserted between adjacent screen modules 1, and can be removed via the locking strip head 10a which typically extends onto the upper surface of the [n:\libll]02266:GJG

M

12 adjacent screen modules 1. The head 10a can be of varying shapes. The laterally extending locking strip 10 helps seal the interface between adjacent modules from the ingress of fines which can quickly wear attachment rails and machine frames in some prior art systems. A modification depicted in Figure 8 to further inhibit the ingress of fines, involves the provision of a groove 22 or projection on the upper surface of each screen module 1 adjacent the end of the screen region which engages a corresponding projection 23 or groove provided on the underside of the head 10a of the locking strip The projection 23 will typically be slightly larger than the groove 22 to provide an interference fit improving the seal created.

Some areas of the screening machine, particularly under exciter beams may provide little clearance for swinging hammers and the like for securing the locking strip 10. In such areas, an alternate locking member 10' may be utilised. The alternate locking member 10' is in the form of a cam key 10' having a generally elliptical form which can be inserted between the adjacent module end flanges 16, as depicted in Figure 7, without significant application of force and then turned through 900 so as to forcibly engage the flange outwardly facing surfaces 9, thereby deflecting the module end flanges 16 into the locked position wedged against the attachment rail flanges 5. Turning the cam key through 90' again will unlock the end flanges 16.

The projections 29' on the cam key 10' extend around its periphery and engage the grooves 17 in the module end flange outwardly facing flange surfaces 9 so as to keep the cam key 10' in the correct plane as it rotated, ensuring the cam key does not tilt or pop out. The size of the projections 29' may increase in the region of the periphery engaging 4' the grooves 17 when the cam key 10' is rotated to the locked position so as to have a wedging effect on the grooves 17, preventing the cam key 10' from rotating when it has 25 reached the locked position. Alternatively, grooves could be provided on the cam key and projections on the flange 16.

Figures 14a through 14c depict the progressive installation and locking of adjacent screen modules 1 using the cam key 10'. The cam key is pushed into position in Figure 14b, typically with hand pressure alone. In Figure 14c the cam key 10' is rotated, preferably by a device such as a spanner applied to the head lOa' of the cam key [n:\lib11]02266:GJG 13 Any number of cam keys 10' can be utilised at any spacing necessary to rigidly lock the screen modules in place. A sealing strip (not shown) should then be located in the recess defined between the adjacent outwardly facing surfaces 9 between the cam keys to prevent the ingress of fines. Locking strips 10 can then be employed where more access is provided. Flexibility in installation is thus provided.

Each attachment rail 3 preferably has two laterally extending and downwardly protruding locating flanges 4 for locating the attachment rail on the frame member, the locating flanges 4 hanging over either side of the frame member. The attachment rail 3 is bolted to the frame member 2 at various locations along its length by means of bolts 20 or screws, the heads of which are preferably housed within a recess in the attachment rail 3.

This system alleviates the problem of many prior art pin systems which do not allow lug fixing pins to be positioned over the top of bolts securing the attachment rail to the machine frame. The attachment rail 3, particularly if provided with the locating flanges 4, protects the frame member 2 from wear as a result of any possible ingress of fines between screen modules 1. The attachment rails 3 may be made with bases 19 of varying width to protect frame members of varying width. The locating flanges 4 and the sloped surface of the attachment rail flanges 5 help to deflect material passing through the screen region away from the frame members 2.

It is preferred that the attachment rail 3 is made from a plastics material (preferably a urethane material), and is internally reinforced with a rigid member, typically by means of steel reinforcing 6. The steel reinforcing 6 can be made as a unitary channel or alternatively fabricated by welding flat plates together along their edges. Encasing the steel reinforcing in urethane renders the attachment rail more tolerant to wear from any fines which may impinge thereon.

Referring to Figures 1 and 2, as briefly discussed above, the screen module 1 typically has a longitudinally extending side reinforcement member 7b disposed adjacent each side of the module body. Opposing ends of each side reinforcement member 7b extend to adjacent respective ends of the screen module. As best depicted in Figure 9, the attachment rail flanges 5 are provided with notches 8, which may extend the full height of the flanges 5 so as to form separate attachment rail flange portions, for receiving the side [n:\libll]02266:GJG 14 reinforcing member ends. In use, the side reinforcement members 7b are thus supported by said attachment rails 3, and in particular the attachment rail base 19 in the embodiment depicted.

Having the side reinforcement member 7b extending over and being supported by the base 19 of the attachment rail 3, avoids the reliance on load transfer through extended lengths of plastics material of the screen module 1. This enhances the rigidity of the installed screen module 1 as the reinforcing members 7b are self supported inside the attachment rail 3. The side reinforcement members 7b may be formed of any sufficiently rigid and strong material such as steel, fibreglass or graphite composites and/or structural urethanes, and are typically in the form of vertical plates, however other configurations may be appropriate depending on the application.

The side reinforcement members 7b are typically encased in longitudinal extension portions 26 of the module body, with the extension portions 26 being received in respective notches 8 of the attachment rail flange 5. The ends 27 of the module end flanges 16 lie between the longitudinal extension portions 26 encasing the side reinforcement members 7b, and are separated therefrom so that deflection of the module Send flanges 16 by the locking member 10 is not inhibited. The longitudinal extension portions 26 also form end walls of the recesses 21 defined between the module end flanges 16 and module body.

To enable the use of a continuous elongate strip locking member 10 across several pairs of longitudinally adjacent screen modules 1, and to avoid any interference fit between longitudinally adjacent screen modules during the locating process, the longitudinal extension portions 26 do not protrude longitudinally as far as the module end flanges 16 in their undeflected position, allowing the elongate strip locking member 10 to be inserted between adjacent longitudinal extension portions 26. The side profile of the longitudinal extension portions are shown in Figures 10 and 11, depicting partial side views of adjacent modules in the unlocked and locked positions respectively. The side profile of the longitudinal extension portions 26 can be seen to approximate that of the module end flanges when in the deflected, locked position.

[n:\Iibil]02266:GJG _~1~111111 The side reinforcement members 7b are typically formed as a vertical steel plate, here approximately 5 mm in width and encased in an extension portion 26 with a total width of about 10 mm. The notches 8 in the attachment rail flanges 5 are approximately mm wide, allowing the adjacent side reinforcement members 7b and associated extension portions 26 to be received in the one notch 8. These notches 8 also serve to prevent the screen modules 1 from vibrating their way sideways along the attachment rails 3.

The central longitudinally extending reinforcement member 7d helps to further reinforce the screen module when desired, and is configured similarly to the side reinforcement members 7b, being encased in a longitudinal extension portion 28 separated from module end flange ends 27. The central longitudinally extending reinforcement members 7d are here approximately 10 mm wide and are encased in a 20 mm wide extension portion 28 such that it also fits into a standard notch 8.

S' The screen module 1 also preferably has a laterally extending end reinforcement member 7a disposed in each module end flange 16. The end reinforcement members 7b, S and the optional central laterally extending reinforcement members 7c are typically formed as bars made of steel and/or other rigid materials as per the side reinforcement 44 4 members 7b.

Referring to Figure 12, modules 1 disposed around the edge of the screening machine may engage the sides 12 of the machine frame by means of end strips 11. In ,44 such an arrangement, the machine edge modules 1 need not be provided with a module end flange at the end adjacent the end strip 11. When the locking member 10 is inserted 44 4 between the opposing end of the edge module and an adjacent module, a force is transmitted longitudinally through the module in the direction of arrow X. The end of the S' 25 module adjacent the end strip 11 thus forces the end strip 11 against the side 12 of the screening machine. A clamping beam 14 is then be placed over the end strip 11 and overlaps part of the module 1. The clamping beam 14 is held in place by means of a wedge 13 which is inserted between the beam 14 and a bracket 15. Whilst this arrangement does not require a module end flange at the end adjacent the end strip 11, an standard module having end flanges 16 at each end could still be employed, the end strip [n:\libll]02266:GJG 16 11 abutting against the end flange outwardly facing surface 9. The end strip 11 may have an L shaped cross section with the end of the module 1 sitting on the base 1 la of the end strip 11 so as to elevate the end of the end module above the frame member 2 a height equivalent to the height the opposing end is raised by the attachment rail 3. This will ensure the edge module sits flat.

Figure 13 shows the preferred way of attaching the screen modules 1 to the side 12 of the screening machine. This arrangement utilises a screen module 1 having module end flange 16 at both ends of the screen region, as per the modules used across the centre of the screening machine. The attachment rail 3a has only one upwardly outwardly protruding attachment rail flange 5 which is attached to the frame member 2 at the edge of the machine. The flange 16 of a screen module 1 is snapped onto the attachment rail 3a in the mannimer described above. A clamping beam 14 having an end portion 14a acting as a locking member is then placed over the end of the screen module with the end portion S 14a deforming the module end flange 16 of the screen module 1 inwardly to wedge it against the attachment rail flange 5. The clamping beam 14 may then be retained by means of a wedge 13 and bracket 15 similar to those described above.

4 4 [n:\Iibll]02266:GJG

Claims (3)

1. A screening assembly for a screening machine comprising: a screen module including: a screen module body having laterally extending ends and longitudinally extending sides bordering a screen region; and a resiliently deflectable, laterally extending and downwardly projecting module end flange disposed at a said module body end, said module end flange having an outwardly facing flange surface defining an obtuse included angle with an adjacent upper surface of said module body, said module end flange further having an inwardly facing flange surface defining a downwardly opening recess with an outwardly facing surface of said module body end; said screening assembly further comprising: a laterally extending attachment rail having a laterally extending attachment 4 rail base adapted to be fixed to, or integrally formed with, a screening machine frame member, said attachment rail further having a laterally extending attachment rail flange S4 projecting upwardly from said base at an acute angle, said screen module being locatable on said attachment rail with said attachment rail flange received in said recess and said 4 4 attachment rail flange projecting upwardly and outwardly with respect to said screen module body; and, a locking member adapted to engage said outwardly facing flange surface following location of said screen module on said attachment rail so as to deflect said module end flange to bring said inwardly facing flange surface into bearing engagement with said attachment rail flange, thereby wedging said module end flange in a locked position between said locking member and said attachment rail flange. 25 2. The screening assembly of claim 1 wherein said flange inwardly facing surface is disposed substantially at right angles to said module body upper surface.

3. The screening assembly of either of claims 1 and 2 wherein said attachment rail flange projects upwardly from said base at an angle of approximately

600. [n:\liblt]02266:GJG 18 4. The screening assembly of any one of claims 1 to 3 wherein said outwardly facing flange surface has at least one groove or projection adapted to engage a corresponding projection or groove provided on said locking member. The screening assembly of any one of claims 1 to 4 wherein said recess substantially encases said attachment rail flange when said module end flange is in said locked position. 6. The screening assembly of any one of claims 1 to 5 wherein said attachment rail is provided with two said attachment rail flanges, each said attachment rail flange projecting upwardly from said base toward the other said attachment rail flange, said screening assembly being provided with two adjacent said screen modules locatable on said attachment rail with said attachment rail flanges each being received in the said recess of the respective said screen module, said locking member being adapted to engage the said outwardly facing flange surface of both said screen modules to wedge both said module end flanges into their locked positions. 7. The screening assembly of claim 6 wherein said attachment rail is adapted to be fixed to said screening machine frame member and includes two laterally extending and downwardly projecting locating flanges for locating said attachment rail on said frame member. 8. The screening assembly of any one of claims 1 to 7 wherein said attachment rail is formed of plastics material internally reinforced with a rigid member. 9. The screening assembly of claim 6 wherein said locking means comprises an elongate strip adapted to engage said outwardly facing flange surfaces of said adjacent screen modules and deform said module end flanges into said locked positions. The screening assembly of claim 9 wherein said locking member further comprises a head adapted to extend onto each said module body upper surface, thereby covering the interfaces between said elongate strip and each said module end flange outwardly facing surface. 11. The screening assembly of claim 10 wherein said module body upper surface of each said adjacent screen module has at least one groove or projection adapted to engage a corresponding projection or groove provided on an underside of said head. [n:\libll]02266:GJG 19 12. The screening assembly of claim 6 wherein said locking member is in the form of a cam key having a generally elliptical form adapted to be inserted between said outwardly facing flange surfaces of said adjacent screen modules, and rotated so as to engage said outwardly facing flange surfaces and thereby deform said module end flanges into said locked positions wedged between said locking member and a said attachment rail flange. 13. The screening assembly of any one of claims 1 to 12 wherein each said screen module is provided with two said module end flanges, a said module end flange being provided at each of said module body ends, said screening assembly being provided with two spaced said attachment rails each associated with a said module end flange. 14. The screening assembly of claim 13 wherein each said screen module is provided with a longitudinally extending side reinforcement member disposed adjacent each said side of said module body, opposing ends of each said side reinforcement member extending to adjacent respective ends of said screen module, said attachment rail flanges being provided with notches for receiving respective said side reinforcing member ends such that, in use, said side reinforcing members are supported by said attachment rails. The screening assembly of claim 14 wherein each lateral end of each said module end flange lies between said side reinforcement members, said ends of said module end flanges being separated from said side reinforcement members so as to enable independent deflection of said module end flanges. 16. The screening assembly of claim 15 wherein said ends of said side reinforcement members are encased in longitudinal extension portions of said module body, said extension portions being received in respective said notches of said attachment 4 .4 rail flange and separated from said ends of said module end flanges. 17. The screening assembly of any one of claims 14 to 16 wherein each said side reinforcement member is formed as a substantially vertical plate. 18. The screening assembly of any one of claims 1 to 17 wherein each said screen module is provided with a laterally extending end reinforcement member disposed in each said module end flange. [n:\libll]02266:GJG 19. The screening assembly of claim 18 wherein each said end reinforcement member is formed as a bar. A locking member for locking adjacent screen modules to an attachment rail in a screening machine, said screen modules having resiliently deflectable laterally extending and downwardly projecting module end flanges located at adjacent ends engageable with laterally extending attachment rail flanges provided on said attachment rail, said locking member being in the form of a cam key having a generally elliptical form adapted to be inserted between said module ends flanges, and rotated so as to engage said module end flanges and thereby deflect said module end flanges into locked positions wedged between said locking member and a said attachment rail flange. 21. A screening assembly for a screening machine comprising: a screen module including: a screen module body having laterally extending ends and longitudinally extending sides bordering a screen region; and a resiliently deflectable, laterally extending and downwardly projecting module end flange disposed at a said module body end, said screening assembly further comprising: a laterally extending attachment rail having a laterally extending attachment rail base adapted to be fixed to, or integrally formed with, a screening machine frame member, said attachment rail further having a laterally extending attachment rail flange S, projecting upwardly from said base, said screen module being locatable on said attachment rail with said attachment rail flange received in said recess, and, a locking member adapted to engage said module end flange following location of said screen module on said attachment rail so as to wedge said module end flange in a locked position between said locking member and said attachment rail flange, wherein said screen module is provided with a longitudinally extending side reinforcement member disposed adjacent each said side of said module body, opposing ends of each said side reinforcement member extending to adjacent respective ends of said screen module, said attachment rail flange being provided with notches for receiving [n:\libll]02266:GJG 21 respective said side reinforcing member ends such that, in use, said side reinforcing members are supported by said attachment rails. 22. The screening assembly of claim 21 wherein each lateral end of said module end flange lies between said side reinforcement members, said ends of said module end flanges being separated from said side reinforcement members so as to enable independent deflection of said module end flanges. 23. The screening assembly of claim 22 wherein said ends of said side reinforcement members are encased in longitudinal extension portions of said module body, said extension portions being received in respective said notches of said attachment rail and separated from said ends of said module end flanges. 24. The screening assembly of any one of claims 21 to 23 wherein each said side reinforcement member is formed as a substantially vertical plate. A screen module for a screening machine substantially as hereinbefore described with reference to Figures 1 to 4, 10 and 11, Figure 8, Figures 5 to 7 or Figure 12 of the accompanying drawings. 26. An attachment rail substantially as hereinbefore described with reference to S, Figures 5 to 7, Figure 8 or Figure 9 of the accompanying drawings. 27. A locking member substantially as hereinbefore described with reference to either of Figures 6 and 8 of the accompanying drawings. 28. A locking member substantially as hereinbefore described with reference to Figure 7 of the accompanying drawings. 29. A screening assembly substantially as hereinbefore described with reference to any one of the accompanying drawings. Dated 8 December, 1998 Cyber Technics Pty Ltd Patent Attorneys for the Applicant/Nominated Person X r22.1 0 [n:\Iib11]02266:GJG