AU2010214788A1 - Disc member for a recycling apparatus - Google Patents

Abstract

There is disclosed a disc member 20 for a recycling apparatus 10. The disc member 20 comprises at least two disc assemblies 21 mountable about a shaft member 15 of the recycling apparatus 10. Each disc assembly 21 comprises a hub portion 22 configured 5 to engage with the shaft member 15 to locate the disc assembly 21 on the shaft member 15; and a disc portion 26 removably mounted to the hub portion 22 to project beyond the hub portion 22 to contact waste material being processed by the recycling apparatus 10 as the shaft member 15 rotates. The at least two disc assemblies 21 interengage about the shaft member 15 to form the disc member 20. .~~'-"~''i 7 2 2< "'7 '7"' 7' <7 7" <7 ' '2 ,"- J I 74<7 '7' "K Ii 2' ~ ' 2 q~j j~~ji~ '4~ ~K 2> 'IL / 2< I- ' '<7 <2 / (' \ II \ 2)

Description

DISC MEMBER FOR A RECYCLING APPARATUS FIELD OF INVENTION This invention relates to a disc member for a recycling apparatus, and in particular to a disc member for a disc screen apparatus for separating mixed matter in a recycling 5 plant. BACKGROUND ART In recent times there has been a significant shift in the management and disposal of waste products generated by society. As part of this shift, much focus has been directed towards the need to reduce the amount of waste products that are being disposed of in 10 landfills, combustion furnaces, and the like. A natural part of this focus has been directed towards identifying ways in which waste products can be recycled or re-used in a manner which not only reduces the reliance on landfills and furnaces to dispose of waste, but which also provides benefit to the environment by reducing societies constant reliance on dwindling natural resources. 15 As a result of this, many communities have introduced programs directed towards having citizens identify and distinguish between waste products and recyclable products at a point of disposal. Typically, this is achieved by providing different bins or receptacles for receiving specific waste matter, which requires individuals to identify a distinction between traditional waste and recyclable material at the point of disposal. 20 Such receptacles are then collected separately with the traditional waste material being processed in a traditional manner such as landfill or burning, and the recyclable waste material being sent to a dedicated processing centre for separation and re-use, where appropriate. Recyclable waste material typically includes such material as paper products, glass and metal products, as well as some plastics and the like. 25 Waste recycling processing centres typically receive mixed recyclable waste products as disposed of by the consumer and employ a variety of separating mechanisms to separate the mixed waste products into waste products of similar materials which can be processed in a similar manner for reuse or reconstitution. Typically, devices such as disc screens are employed to receive the mixed waste and to handle the mixed waste in a 30 manner that enables materials of similar matter to be collected. Such disc screens not only assist in sorting or separating streams of mixed waste material but also act to process and transport such matter to dedicated processing stations, within the waste recycling centre. Typically, disc screens comprise a plurality of rotatable shafts arranged in a parallel manner to form a bed or surface upon which the mixed waste material is deposited. A plurality of discs are mounted to the shafts so as to rotate with the shafts to aid in conveying the deposited waste material along a processing path. The discs are typically mounted in close proximity along a shaft with discs of adjacent shafts overlapping to 5 form a transporting surface along which the waste material is propelled. The external diameter of the discs are typically provided with an irregular contour and are comprised of a rubber or similar gripping material which grip the waste material deposited thereon and agitate the waste material. As gaps are provided between adjacent discs, waste material of a certain size or property may fall through the disc screen to be collected 1o below for further processing. Waste material of a larger size is then thrown along the path of the screen due to the action of the rotating discs for transportation further down the processing line. Typically, waste materials of differing sizes and/or weights will travel along the disc screen in a different manner enabling natural separation and collection of such material. 15 Traditionally, the discs employed in disc screens of the type referred to above, require an outer surface of material having a high coefficient of friction in order to grip the waste material and transport it along the path of the disc screen, but also require a degree of impact resistance so as not absorb impact forces when the waste material impacts upon the discs. For this reason, a rubber material is typically employed to 20 achieve this function. It has been found that due to the highly abrasive nature of the process, such discs typically wear over time and require constant replacement as the rubber deteriorates and the discs lose their ability to function in a desired manner. Such discs typically comprise a metallic inner frame which is mountable directly to a shaft. The rubber material is typically moulded about the inner metal frame to form the 25 overall disc. The discs may be provided in two or more parts so that they can be assembled to the shaft to form a disc member. As the rubber portion of the discs experiences significant wear, once the disc has been deemed to no longer be effective and requires replacement, the disc members are often disposed of including the metal inner frame portion and are unable to be reused or recommissioned for use. As such, 30 the replacement of discs can be a costly and wasteful exercise for most waste recycling plant operators. As such, there is a need to provide a disc element for a disc screen that can be readily recommissioned for use and easily assembled for use, as required by recycling plant operators. 35 The above references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the above prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part. 5 STATEMENT OF INVENTION Accordingly, in one aspect of the invention there is provided a disc member for a recycling apparatus comprising; at least two disc assemblies mountable about a shaft member of the recycling apparatus, each disc assembly comprising; 10 a hub portion configured to engage with the shaft member to locate the disc assembly on the shaft member; and a disc portion removably mounted to the hub portion to project beyond the hub portion to contact waste material being processed by the recycling apparatus as the shaft member rotates; 1s wherein, the at least two disc assemblies interengage about the shaft member to form the disc member. In one embodiment, the two disc assemblies are mountable about the shaft member and each disc assembly is substantially identical in configuration. In another embodiment a plurality of disc assemblies may be mounted about the shaft member. 20 The hub portion may be a metal frame comprising a pair of opposed face members between which the disc portion is received. One or more recesses may be provided in the face members to align with one or more holes formed in the disc portion to enable a retaining member to pass therethrough to removably secure the disc portion to the hub portion. The retaining member may be a bolt that passes through the aligned recesses in 25 the face members and the hole in the disc portion to engage with a nut to removably secure the disc portion to the hub portion. The face members may have a cut-out region formed therein configured to conform to the shape of the shaft member to facilitate engagement with the shaft member. At least one base plate may extend between the face members proximal the cut-out region and a 30 pin may project from the at least one base plate to extend into the cut-out region, to be received within a hole provided in the shaft member to locate the disc assembly on the shaft member.

The disc portion may be made from an elastomeric material, such as rubber. The disc portion may have a contoured outer surface that extends from the hub portion to contact waste material being processed by the recycling apparatus. The contoured outer surface of the disc portion may comprise a series of stepped regions formed therein. The disc 5 portion may have a substantially semi-circular shape. In one embodiment, when the two disc assemblies are mounted about the shaft member, the hub portions of each disc assembly are connectable. The at least one base plate of the hub portions of the disc assemblies may have a pair of recesses formed therein at opposing ends of the hub portions and an engagement member may be passed through 10 the recesses in opposing ends of the hub portions to facilitate connection between disc assemblies the engagement member may be a bolt or similar device. When the two disc assemblies are mounted about the shaft member, the outer surfaces of the corresponding disc portions of the disc assemblies may form a continuous outer surface of the disc member. 15 Accordingly, in another aspect of the invention there is provided a disc assembly for forming a disc member mountable about a shaft member of the recycling apparatus, comprising: a hub portion configured to engage with the shaft member to locate the disc assembly on the shaft member; and 20 a disc portion removably mounted to the hub portion to project beyond the hub portion to contact waste material being processed by the recycling apparatus as the shaft member rotates. In this aspect, the hub portion may comprises a pair of spaced apart face members between which the disc portion may be received. One or more recesses may be 25 provided in the spaced apart face members to align with one or more holes formed in the disc portion when the disc portion is received therebetween, the one or more recesses and corresponding one or more holes, form one or more paths for receiving a retaining member therethrough to removably secure the disc portion to the hub portion. The disc portion may be made from an elastomeric material. The disc portion may have 3o a contoured outer surface to contact waste material being processed by the recycling apparatus. The contoured outer surface of the disc portion may comprise a series of step regions formed about the periphery thereof. BRIEF DESCRIPTION OF THE DRAWINGS The invention may be better understood from the following non-limiting description of preferred embodiments, in which: Figure 1 is side elevation view of a disc screen apparatus of the prior art; Figure 2 is a plan view of a disc screen section of Figure 1; 5 Figure 3 is an enlarged view of a shaft and disc arrangement according to the disc screen section of Figure 2; Figure 4 is a plan view of a disc member in accordance with an embodiment of the present invention; Figure 5 is an exploded view of the disc member of Figure 4; 10 Figure 6 is a side view of a half disc assembly of the disc member of Figure 5; Figure 7 is an exploded view of the half disc assembly of Figure 6; Figure 8 is a plan view of a section of a hub portion of the half disc assembly of Figure 7; Figure 9 is an end view of the disc member of Figure 4; and 15 Figure 10 is a sectional end view of the disc member of Figure 4. DETAILED DESCRIPTION OF THE DRAWINGS Preferred features of the present invention will now be described with particular reference to the accompanying drawings. However, it is to be understood that the features illustrated in and described with reference to the drawings are not to be 20 construed as limiting on the scope of the invention. Referring to Figure 1, there is shown a diagrammatic representation of a disc screen apparatus 10 typically used for processing material in a recycling plant. The disc screen apparatus 10 as shown comprises three sections, namely a first disc screen section 11, a second disc screen section 12 and a third disc screen section 13. It will be appreciated 25 that the number of disc screen sections provided in a disc screen apparatus may vary whilst remaining within the spirit of the present invention. In the embodiment as shown in Figure 1, each disc screen section 11, 12 and 13 is inclined from a horizontal plane and is positioned in close proximity such that the top end of one of the disc screen sections is located over a lower end of the next disc screen 30 section. Such an arrangement enables the disc screen sections to function to convey waste material along the disc screen apparatus 10 in the direction of arrow A. In this regard, a recycling plant may comprise a number of disc screen apparatus 10 configured in a variety of different ways, to process waste material. Each disc screen section 11, 12, 13 comprises a frame 18 having a plurality of shafts 15 5 mounted therein. Each shaft 15 extends across the width of the frame 18 and has a plurality of discs 14 mounted thereon in a spaced manner along the length of the shaft 15. The shafts 15 are mounted in close proximity and the discs 14 on adjacent shafts are offset such that the discs 14 of adjacent shafts 15 overlap. The shafts 15 are typically driven by a belt system or the like such that they each rotate in a controlled and 1o consistent manner, thereby imparting rotational motion to the corresponding discs 14. It will be appreciated that due to the close proximity of the shafts 15 and the nature in which the discs 14 are mounted to the shafts and overlap with discs of adjacent shafts, the discs 14 form a bed or surface upon which unsorted waste material can be received, and along which the waste material can be transported to separate the waste material 15 into similar classed waste. The spacing between discs 14 along the length of each shaft 15 together with the spacing between discs 14 of adjacent shafts 15 is controlled to provide gaps therebetween, through which waste material of a suitable size can pass through, under gravity. As is shown in Figure 1, a conveyor or collection pit 17 is located below the 20 disc screen sections 11, 12, 13 to collect the waste material that falls through the gaps in the disc screen sections such that the collected waste material can be transported to a dedicated treatment site for further processing. For waste material of a larger size and weight, the rotating discs 14 transport the waste material along the surfaces of the disc screen sections 11, 12, 13, in the direction of 25 arrow A, continually separating smaller and heavier waste material in the process. Due to the inclination of the disc screen sections 11, 12, 13, some larger waste material may drop or roll of the bottom of the disc screen sections onto the conveyor or collection pit 17. The discs 14 are formed from a rubber compound having a contoured outer surface that grips the waste material as the disc rotates and projects the waste material along the 30 disc screen sections 11, 12, 13 in the direction of arrow A. As such, waste material of a similar size, weight and constitution is separated, collected and transported by the disc screen sections. Waste material of a larger size, weight and/or constitution is separated as it falls from or through the disc screen sections to the conveyor 17 where it is transported for further processing. 35 Referring to Figure 2, a top view of disc screen section 11 of Figure 1 is shown. Shafts 15 are mounted between two end portions of the frame 18, and a drive mechanism 19 engages with an end of the shafts 15 to cause the shafts to rotate about their central axis in a controlled manner. In the embodiment as shown, the drive mechanism 19 is a chain member driven by a drive motor (not shown) that is enclosed within the frame 18. However, it will be appreciated that the drive mechanism may take a variety of forms 5 such as a screw-drive mechanism or the like and still fall within the spirit of the present invention. As shown in Figure 3, the discs 14 are mounted to the shaft 15 such that there is a constant space "X" between adjacent discs 14. The discs 14 comprise a central raised region 14a that projects beyond the disc body 14b. The raised region 14a may be 10 contoured or grooved such that it contacts with and imparts motion to the waste material to propel the waste material along the surface of the disc screen section 11. Referring to the upper portion of the disc screen section of Figure 2, the position of the discs 14 on adjacent shafts 15 is offset such that the discs 14 of adjacent shafts 15 overlap. This provides a surface upon which the waste material is firstly received and along which the 15 waste material can travel with relatively small gaps provided between discs to control the size of the waste material that passes therethrough. It will be appreciated that the spacing between adjacent shafts 15 and the spacing "X" between adjacent discs 14 along each shaft may be varied to alter the size of waste material that can pass through the disc screen section 11. This is useful in controlling separation of the waste material 20 based on size, weight, and material properties. According to Figures 4 - 10, a disc member 20 in accordance with an embodiment of the present invention is shown. The disc member 20 is configured to function in the manner as described above in relation to conventional discs 14. As is shown in Figure 5, the disc member 20 comprises two parts or half disc assemblies 25 21 that fit together about a shaft 15 so as to be securely mounted to the shaft. In the embodiment as shown, the half disc assemblies 21 are substantially mirror images of each other and fit together about the shaft 15 to form a disc member 20 having a substantially continuous periphery. The shaft 15 is in the form of a hollow steel beam having a substantially square cross-section. The square shaped cross-section of the 30 shaft 15 enables the parts 21 of the disc member 20 to clamp about the shaft in a manner that ensures positive engagement with the shaft 15. Further, such a shaft configuration has particular application for a disc screen apparatus 10 that handles a variety of waste material. In this regard, should elongate waste material such as rope, twine, plastics and the like which may be present in the waste material being processed by the disc screen 35 apparatus become entangled about the shaft 15 during use, the square nature of the shaft 15 facilitates easy cutting and removal of such waste material. However, it will be appreciated that the shaft 15 may assume a variety of cross-sections, including circular, oval, triangular, etc, and still fall within the spirit of the present invention. Each half disc assembly 21 comprises a hub portion 22 that is configured to attach to the shaft 15, and a disc portion 26 that is mounted to the hub portion 22. The disc portion 26 is made from an elastomeric material such as rubber and the like. 5 The elastomeric material has high impact and abrasion resistance to avoid damage when the disc portion 26 contacts the waste material during use, and also has a high coefficient of friction to grip and convey the waste material along the disc screen section. As is shown most clearly in Figure 6, the outer surface or periphery 27 of the disc portion 26 has an irregular surface made up of stepped regions to aid in agitating 10 the waste material when in use as well as to increase the ability of the disc member 20 to grip and advance the waste material along the surface of the disc screen section. It will be appreciated that the actual shape or profile of the outer surface or periphery 27 of the disc portion may assume a variety of different configurations whilst still falling within the spirit of the present invention. 15 Referring to Figures 7 and 8, the hub portion 22 is shown in isolation. The hub portion 22 is in the forn of a metal frame made frorn aluminium, steel or the like. The frame comprises a pair of opposing face members 23, separated at their lower regions by a pair of base plates 24. The face members 23 and base plates 24 are assembled together such that the frame of the hub portion 22 forms a substantially open channel 22a. The open 20 channel 22a is formed about the upper periphery of the hub portion 22 and is shaped to receive a base of the disc portion 26, in the manner as shown in Figure 7. One or more support members 25 are provided on the peripheral edges of the face members 23, adjacent the open channel 22a, to abut with the disc portion 26 when it is received within the open channel 22a, as is shown in Figure 6. 25 In order to secure the disc portion 26 in the open channel 22a of the hub portion 22, recesses 23a are formed in each of the face members 23. The recesses 23a align with corresponding recesses formed in the opposing face 23, and also align with holes 28 provided in the base region 26a of the disc portion, when the disc portion 26 is inserted into the hub potion 22. The alignment of recesses 23a and holes 28 enable a bolt 29a to 30 be employed to pass through the half disc assembly to secure the hub portion 22 and the disc portion 26 together into a common unit. A nut 29b is provided to complete the connection between the hub portion 22 and the disc portion 26 and due to the threaded nature of the nut 29b and bolt 29a, such a connection may be removable to facilitate disassembly of the half disc assembly 21, as desired. Other means of connection of the 35 nut 29b and bolt 29a are also envisaged, such as an interference fit and the like. As shown more clearly in Figure 8, in order to secure the half disc assembly 21 to the shaft 15, the face members 23 have a cut out 32 formed therein. The cut-out 32 has a square-edge configuration to conform to the square profile of the shaft 15. However, the shape of the cut out may vary to conform to shafts 15 having different shaped cross sections. A locking pin 30 is also provided to extend from one of the base plates 24 of 5 the hub portion 22. The locking pin 30 is secured, by welding or a similar process, within a recess formed in the base plate such that it extends into the cut-out region 32 formed between the face members 23, as shown in Figure 6. In such an arrangement, when the half disc assembly 21 is mounted to the shaft 15, in the manner as shown in Figure 5, the half disc assembly 21 is correctly orientated in the desired position by the 10 locking pin 30 being received within a recess 15a provided in the shaft 15. This ensures that the disc member 20 is correctly spaced with respect to adjacent disc members along the length of the shaft 15. Each half disc assembly 21 is mounted to the shaft 15 in the manner as shown in Figures 9 and 10. To facilitate connection of half disc assemblies 21, the base plates 24 have a 15 pair of holes 24a and 24b formed in the substantially horizontal portions thereof, as shown in Figure 8. Hole 24b is in the form of an elongate tubular portion having an internal thread formed therein. Referring to Figure 10, to fix the disc member to the shaft 15, the half disc assemblies 21 are brought together and positioned on the shaft 15 such that the locking pins 30 are 20 received within holes 15a formed in opposing sides of the shaft. In such a position the hole 24a of one half disc assembly 21 aligns with the hole 24b of the other half disc assembly 21. A bore 35 is formed through the disc portion 26 from the outer surface or periphery 27 to enable a bolt 36 to be received therein. The bolt 36 passes through the hole 24a of one half disc assembly 21 and is received in the hole 24b of the other half 25 disc assembly 21 where it threadingly engages the two half disc assemblies together. Another bolt 36 performs the same task on the other side of the shaft 15 such that the disc member 20 is securely positioned on the shaft 15. As discussed above, during use of the disc member 20 of the present invention, it is common for the disc portion 26 of the half disc assembly 21 to wear and deteriorate 30 during use. This is because the disc portion 26 is in constant contact with the waste material and undergoes significant impact and abrasive forces during use. Traditional disc members used for such purposes employ a central or inner metal frame and the rubber material is moulded or otherwise coated around the inner frame. As a result, in order to replace the disc member in such prior art arrangements it has been necessary to 35 remove the half disc assemblies and discard them and replace the half disc assemblies with new assemblies. As such conventional half disc assemblies are integral pieces it has not been possible to disassemble the various parts of the disc member for reuse, without undergoing significant treatment steps to separate the components. The disc member 20 of the present invention offers a significant improvement over such conventional disc members as the disc portion 26 and the hub portion 22 of the half disc assemblies 21 are able to be simply disassembled to enable replacement of worn parts 5 and reuse of components. As the disc assemblies are not integrally forced, in the event of a worn disc portion, the disc portion can be easily removed from the hub portion to enable replacement of a new disc portion 26, without having to discard the hub portion 22. Such an arrangement significantly reduces costs associated with maintaining and running a recycling plant and provides a significant reduction in the use of raw 10 materials. By enabling re-use of the hub portion 22, upon wearing of the disc portion 26, the disc portion 26 can be simply removed from the hub portion 22 and replaced with a new disc portion. Such a process is easy to perform and enables mass production of disc portions 26 for reuse. 1s Throughout the specification and claims the word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word "comprise" and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features 20 not specifically listed, unless the contrary is expressly stated or the context requires otherwise. Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be 25 considered in a particular orientation, typically with the disc member uppermost. It will be appreciated by those skilled in the art that many modifications and variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention.

Claims (20)

1. A disc member for a recycling apparatus, comprising: at least two disc assemblies mountable about a shaft member of the recycling apparatus, each disc assembly comprising; 5 a hub portion configured to engage with the shaft member to locate the disc assembly on the shaft member; and a disc portion removably mounted to the hub portion to project beyond the hub portion to contact waste material being processed by the recycling apparatus as the shaft member rotates; 10 wherein, the at least two disc assemblies interengage about the shaft member to form the disc member.

2. A disc member according to claim 1, wherein two disc assemblies are mountable about the shaft member to form the disc member.

3. A disc member according to claim 2, wherein the hub portion comprises a pair of 1s spaced apart face members between which the disc portion is received.

4. A disc member according to claim 3, wherein one or more recesses are provided in the spaced apart face members to align with one or more holes formed in the disc portion when the disc portion is received therebetween, the one or more recesses and corresponding one or more holes, form one or more paths for 20 receiving a retaining member therethrough to removably secure the disc portion to the hub portion.

5. A disc member according to claim 4, wherein the retaining member is a bolt that passes through the one or more paths to engage with a nut to removably secure the disc portion to the hub portion. 25

6. A disc member according to claim 3, wherein the face members have a cut-out region formed therein that is configured to conform to a shape of the shaft member to facilitate mounting of the hub portion to the shaft member.

7. A disc member according to claim 6, wherein at least one base plate extends between the face members proximal the cut-out region and a pin projects from 30 the at least one base plate to extend into the cut-out region, said pin being configured to be received within a hole provided in the shaft member.

8. A disc member according to claim 3, wherein the disc portion is made from an elastomeric material.

9. A disc member according to claim 8, wherein the disc portion has a contoured outer surface to contact waste material being processed by the recycling 5 apparatus.

10. A disc member according to claim 9, wherein the contoured outer surface of the disc portion comprises a series of step regions formed about the periphery thereof.

11. A disc member according to any one of claims 8 to 10, wherein the disc portion 10 is substantially semi-circular in shape.

12. A disc member according to any one of claims 2 - 11, wherein when the two disc assemblies are mounted about the shaft member, the hub portions of each disc assembly are connectable.

13. A disc member according to claim 12, wherein the at least one base plate of the 1s hub portion has a recess formed at opposing ends thereof, wherein when the disc assemblies are mounted about the shaft member an engagement member is passed through the corresponding recesses in opposing ends of the hub portions to facilitate connection between disc assemblies

14. A disc member according to claim 12, wherein when the two disc assemblies are 20 mounted about the shaft member, the outer surfaces of the corresponding disc portions of the disc assemblies form a continuous outer surface of the disc member.

15. A disc assembly for forming a disc member mountable about a shaft member of the recycling apparatus, comprising: 25 a hub portion configured to engage with the shaft member to locate the disc assembly on the shaft member; and a disc portion removably mounted to the hub portion to project beyond the hub portion to contact waste material being processed by the recycling apparatus as the shaft member rotates. 30

16. A disc assembly according to claim 15, wherein the hub portion comprises a pair of spaced apart face members between which the disc portion is received.

17. A disc assembly according to claim 16, wherein one or more recesses are provided in the spaced apart face members to align with one or more holes fonned in the disc portion when the disc portion is received therebetween, the one or more recesses and corresponding one or more holes, form one or more paths for receiving a retaining member therethrough to removably secure the disc 5 portion to the hub portion.

18. A disc assembly according to claim 15, wherein the disc portion is made from an elastomeric material.

19. A disc assembly according to claim 18, wherein the disc portion has a contoured outer surface to contact waste material being processed by the recycling 10 apparatus.

20. A disc assembly according to claim 19, wherein the contoured outer surface of the disc portion comprises a series of step regions formed about the periphery thereof.