GB2440261A

GB2440261A - Rotary crushing apparatus with polygonal drum

Info

Publication number: GB2440261A
Application number: GB0713875A
Authority: GB
Inventors: John Gilleece
Original assignee: J G Crushing & Recycling Ltd
Current assignee: J G Crushing & Recycling Ltd
Priority date: 2006-07-18
Filing date: 2007-07-17
Publication date: 2008-01-23
Anticipated expiration: 2027-07-17
Also published as: GB2440261B; GB0713875D0; GB0614225D0

Abstract

A rotary crushing apparatus 10 comprises feeding mechanisms 12 for feeding material to a crusher. The crusher comprises a rotatable polygonal drum (50, fig.2) and at least one crushing plate (62, 64, fig.2) in operative association with the drum (50, fig.2) to crush said material therebetween. The crushing plates (62, 64, fig.2) are pivotable towards and away from the drum (50, fig.2). A first feeding mechanism comprises a conveyor 30, a second feeding mechanism comprising a hopper 40. The crushing apparatus 10 is intended for crushing concrete. Multiple feeding mechanisms 30, 40 allow for different forms of concrete to be crushed e.g. concrete slabs or concrete aggregate.

Description

1 2440261 A Crushing apparatus

Field of the Invention

The present invention relates to crushing apparatus.

More specifically, the invention relates to concrete crushing apparatus.

Background to the Invention

Conventional concrete crushing apparatus tend to comprise crushing mechanisms that allow only one form of concrete to be crushed, for example, concrete slabs or concrete aggregate. Thus, to crush different forms of concrete, a number of separate crushing apparatus are required.

It would be desirable to provide an apparatus that mitigates the problem identified above.

Summary of the Invention * **. ***. * * **.*

The invention provides a crushing apparatus comprising * ** means for feeding the apparatus with material to be * 25 crushed; and means for crushing said material, wherein ** ** said crushing means comprises a rotatable drum and at * * S * * least one crushing member in operative association with *** S*S * the drum to crush said material therebetween during use, said feeding means being arranged to deliver said material between said drum and said at least one crushing member.

In a preferred embodiment, the grinding/crushing means takes the form of an impact crusher comprising a drum and at least one, and preferably at least two, plates.

S Preferably, the or each plate has an obverse face which faces the drum, the plate being adjustable such that the spacing between the obverse face and the drum is variable. Conveniently, the plate is pivotable about an axis that is substantially parallel with the axis of rotation of the drum.

In the preferred embodiment, two plates are provided, one on either side of the drum.

In the preferred embodiment, the transporting/sorting means comprises a first conveyor located below and substantially in register with the drum, and a second conveyor located beyond the drum, and preferably also below the drum, with respect to a first feeding means.

Advantageously, the first and second conveyors are :. arranged to convey material deposited thereon in different, e.g. mutually perpendicular, directions.

The grinding/crushing means can crush the variety of + 25 materials and/or different forms of a material that are fed into the crushing apparatus. * * S * S

S S....

* In a preferred embodiment, the positions of the plates are adjustable with respect to the drum such that the grinding/crushing means can accept and crush varying sizes of input material and also produce varying sizes of output material.

In a preferred embodiment, the feeding means, grinding/crushing means and sorting/transporting means are assembled on a frame or supporting skeleton to form the crushing apparatus.

The drum advantageously has a polygonal cross section, and preferably a substantially hexagonal cross section.

More generally, it is preferred that the drum has a plurality of crushing faces, adjacent crushing faces being non-coplanar. Preferably the exterior surface of the drum has teeth. Preferably the exterior surface of the plates have teeth. Preferably the teeth of the plates are offset with respect to the teeth of the drum.

Advantageously, at least one of the conveyors is magnetised. I. * S

In a more preferred embodiment, the crushing apparatus S...

forms part of a motor vehicle assembly such that the * S. S..,.' crushing apparatus is transportable.

25 In the preferred embodiments, the crushing apparatus is ** ** used to crush concrete materials, such as concrete : . slabs and concrete aggregate. More preferably, the *.. *.* * 1 crushing apparatus is used to crush hollow concrete core slabs with wire reinforcement.

Further advantageous aspects of the invention will become apparent to those ordinarily skilled in the art upon review of the following description of a specific embodiment and with reference to the accompanying drawings.

Brief Description of the Drawings

Embodiments of the invention is now described by way of example and with reference to the accompanying drawings in which similar numerals are used to indicate like parts and in which: FIGURE 1 shows a side view of part of a crushing apparatus embodying the invention; FIGURE 2 shows a perspective view of a grinding/crushing means included in the crushing apparatus of Figure].; :. FIGURE 3 shows a side view of an adjustment mechanism; * *** **** * S * S5S FIGURE 4 shows an end view of the crushing apparatus * S. mounted on a vehicle assembly; and ** 25 * , FIGURE 5 shows a side sectional view of part of an * alternative embodiment of a crushing apparatus.

S..... * S

Detailed Description of the Drawings

Referring now to Figure 1 of the drawings, there is shown, generally indicated as 10, a preferred embodiment of a crushing apparatus. The crushing apparatus 10 comprises means for feeding 12 the S apparatus 10 with material to be crushed, means for grinding or crushing 14 the material, and means for sorting and transporting 16 the material once it has been crushed. The feeding means 12, crushing means 14 and transporting means 16 may be carried by a frame or other supporting structure in any convenient manner.

The frame is not shown in Figures 1 and 2 for reasons of clarity, although a suitable frame 17 is shown in Figure 4 by way of example. The frame may be of a conventional nature, the design of which would be within the capability of any suitably skilled person.

The feeding means 12, in the illustrated embodiment, comprises two feeding mechanisms in the form of a conveyor 30, e.g. a belt type conveyor or a roller type conveyor, and a hopper 40 respectively. The conveyor :. 30 is preferably a belt type conveyor, including an S..... endless belt 31, preferably a steel belt. By way of S...

example, the conveyor belt 30 may be approximately 6m *:*::* long.

The conveyor 30, which may be of a conventional design, * has first and second ends and is arranged to transport S S....

* material towards the second end as indicated by arrow B. The second end of the conveyor belt 30 is positioned at or adjacent the crushing means 14 such that, in use, material transported by the conveyor 30 is fed into the crushing means 14. The speed of the conveyor 30 is preferably adjustable.

The conveyor 30 is shown in a substantially horizontally orientation. In preferred embodiments, the conveyor 30 is pivotably mounted on the apparatus about an axis that is substantially parallel with the plane in which the conveyor lies and which is located at or adjacent said second end. The preferred arrangement is such that the first end may be raised or lowered with respect to the second end, thereby adjusting the angle of inclination of the conveyor 30 with respect to the crusher 14. The conveyor 30 may be pivoted and held in a desired position by any suitable means, for example one or more hydraulic rams (not shown) or other actuator: The hopper 40, which may also be of conventional design, has first and second ends 41, 43 each defining a mouth. In use, material is fed into the hopper 40 via the mouth at the first end 41 and is directed towards and out of the mouth at the second end 43 (as indicated * S S..

by directional arrow C). The second end 43 of the * .* hopper 40 is positioned at or adjacent the crushing means 14 such that, in use, material within the hopper ** ** 40 is fed to the crushing means 14. In the illustrated : embodiment, the first and second ends of the hopper 40 S.....

* are open, although alternatively a lid or door (not shown) may be provided to allow the ends to be closed.

The hopper 40 is conveniently located above the crushing means 14 such that material entering the hopper 40 falls under gravity towards the crushing means 14.

The crushing means 14, shown in more detail in Figure 2, preferably takes the form of an impact crusher and comprises a rotatable drum 50. The drum 50 is rotatable about an axis A-A' which, during normal use, is intended to be substantially horizontally disposed, or substantially parallel with the ground upon which the apparatus 10 sits. In the preferred embodiment, the axis A-A' is substantially perpendicular with the direction in which conveyor 30 is arranged to feed material to the crusher 14. Typically, axis A-A' is also substantially perpendicular with the direction in which hopper 40 is arranged to feed material to the crusher 14. The apparatus 10 also includes means for driving the drum 50 about axis A-A'. The drive means (not shown) may comprise, for example, a hydraulic motor and associated driving mechanism(s) for coupling it to the drum 50, although any other suitable drive means, especially powered (e.g. electrical, hydraulic or pneumatic) drive means. * S * S.

The drum 50, or at least its exterior surface, is substantially rigid and is typically made from a rigid material, especially metal, e.g. steel. In the embodiment shown, the drum 50 has a hexagonal *5SS5* * transverse cross section. The drum 50 may alternatively have other transverse cross sectional shapes, although it is preferred that the shape is a polygon, especially a regular polygon, since the resulting surface edges facilitate the crushing action.

The exterior surface of the drum 50 preferably has teeth 52, which in this example, are spaced apart along the length of the drum 50 in axial direction A-A'.

Each tooth 52 preferably extends circumferential].y around the drum 50, although the annular teeth shown in the drawings could be replaced with any suitable alternative, for example a plurality of teeth spaced apart around the circumference of the drum. Preferably, the teeth 52 have a substantially triangular cross section. The teeth 52 may for example be made of ox steel.

The drum 50 is positioned at or adjacent the feeding means 12, such that, the longitudinal axis (and rotational axis) of the drum 50 (indicated as A-A') is substantially perpendicular to the direction in which material is directed and fed via the feeding means 12 : towards the crushing means 14. The drum 50 is s.::: preferably rotatable in both clockwise and S...

anticlockwjse directions about the axis A-A'. The drum may, for example, be approximately 1.lm in diameter.

At least one crushing member 60, in the preferred form : of a crushing plate, is associated with the drum 50, SS:ss: the crushing member having an obverse surface 63, 67 that faces the drum 50. In the illustrated embodiment, two crushing plates 62, 64 are provided, one plate 62 being positioned to catch material fed to the crusher 14 from conveyor 30 and to direct said material between the plate 62 and the drum 50, the other 64 being positioned to catch material fed to the crusher 14 from the hopper 40 and to direct said material between the plate 64 and the drum 50.

The plates 62, 64 preferably comprise substantially planar panels, preferably made of a rigid material, typically metal, or at least having a rigid obverse face. The first plate 62 is located adjacent the second end of the conveyor 30 and the drum 50 while the second plate 64 is located adjacent the second end of the hopper 40 and the drum SO. Both plates 62, 64 are typically positioned to leave a gap between the drum SO and respective plates 62, 64. In the illustrated embodiment, the arrangement is such that there is a gap between the ridges formed in the exterior surface of the drum 50 and the plates 62, 64 when the ridges are at their closest to the plates 62, 64, although in an alternative arrangement one or both of these gaps may be closed. Optionally, the or each plate may be resiliently biased, e.g. by one or more springs, S...

towards the drum 50. * ** ** . * S*

* 25 In use, material leaving the respective adjacent S..

feeding means 12 falls under gravity between the drum and crushing members 60. Additional guiding means may be provided, such as a slide or chute, to direct material from the feeding means 12 towards the gap between the drum 50 and plates 62, 64. In Figure 1, a chute 69 is provided at the end 43 of the hopper 40.

In the embodiment shown, the plates 62, 64 are, by way of example, substantially rectangular in shape and are substantially equal in length to the drum 50. Both the first and second plates 62, 64 preferably have teeth 66 on their obverse face, which, in this example, are arranged in a row extending along the length of the plate 62, 64 (parallel with axis A-A'). Each tooth 66 preferably runs substantially perpendicular to axis A-A' and, more preferably, has a substantially triangular cross section. Preferably the teeth 66 of the panels 62, 64 are offset laterally (i.e. in direction A-A') with respect to the teeth 52 of the drum 50. Hence, depending on the spacing between the drum 50 and the plates 62, 64, and on the angular position of the drum, the teeth 66 may fit between the teeth 52, at least along part of their length.

It is advantageous that the positions of both the first and second plates 62, 64 are adjustable such that the gap between the drum 50 and respective plates 62, 64 can be changed. In particular, it is preferred that the plates 62, 64 may be pivoted or tilted about an *:*::* axis that is substantially parallel with axis A-A'. In * 25 the illustrated example, the plates 62, 64 are S..

pivotable about their in use lower ends (by any :*. convenient hinge or pivoting mechanism), but may alternatively be pivotable about their other end, or any point in between. By way of example, Figure 3 shows an embodiment of a mechanism 80 for adjusting the position of the plates 62, 64, in which a conventional screw thread adjustment bar is provided between the plate 62, 64 and the frame (not shown).

Figure 5 shows part of an alternative embodiment of the crushing apparatus which is similar to apparatus 10 and in which like numerals are used to indicate like parts.

The drum 150 has an octagonal transverse cross-section.

The crushing members 162, 164 are pivotable about a respective pivot mechanism 171, 173 about a respective axis that is substantially parallel with the rotational axis of the drum 150. A respective interengaging pin-and-slot mechanism 175, 177 is provided to guide the pivoting movement of the members 162, 164 and to limit the extent of their travel. At least one of the crushing members 162, 164, and in particular the one associated with the hopper 40, is non-linear in transverse cross section, e.g. is comprised of two (or more) flat sections disposed at an angle, preferably an obtuse angle, to one another. The angle between sections may be substantially the same as the angle between adjacent surface sections of the drum 150. A guide member 179, preferably in the form of a plate, may be provided at the other side of the hopper 40 to the guide 65, and arranged to guide material from said * 25 hopper 40 onto the crusher 14 so that it may be fed S. towards the crushing plate 164. * .. * . S * .

The sorting/transporting means 16, of the illustrated embodiment, comprises first and second conveyors, e.g. belt type conveyors, 70a, 70b. The conveyors 70a, 70b may be of a conventional nature with first and second ends whereby material placed at or adjacent a first end of a respective conveyor 70a, 70b is transported towards the second end (as indicated by directional arrow D). The first ends of the respective conveyor belts 70a, 70b are located at or adjacent (and preferably below, in use) the crusher 14 such that material which passes through the crusher 14 is collected at or adjacent the first ends of the respective conveyors 70a, 70b. In the illustrated embodiment, the first conveyor 70a is located, in use, substantially directly below the crusher 14 while the second conveyor 70b is located below the crusher 14 but beyond the crusher 14 with respect to the conveyor 30.

The conveyors 70a and 70b transport material in substantially perpendicular directions. It is envisaged however, that the conveyor belts 70 may be positioned to transport material in any direction.

In use, some of the material which passes through the crusher 14 falls onto the first conveyor 70a while other material passing through the crusher means is directed onto the second conveyor 7Ob. The second S....' conveyor 70b is preferably magnetised so that it may attract magnetic objects. For example, all or part of * S. * 25 the belt of conveyor 70b may be magnetised. In the embodiment shown, the conveyors 70a, 70b are substantially horizontally disposed. In an alternative embodiment however, the conveyors 70a, 70b are pivotable such that the belt can be held at an angle with respect to horizontal. In this preferred embodiment it is envisaged that the conveyors 70a, 70b are pivotable about their first ends and that the respective second ends of the conveyor belts 70a, 70b may be raised or lowered by at least one hydraulic ram (or other actuator) as shown in Figure 4.

The feeding means 12, crusher 14 and sorting/transporting means 16 are powered by at least one motor (not shown) in any suitable conventional manner. The motor(s) may take any suitable form and may be operated by any suitable means, e.g. a hydraulic pump. Preferably the speed of the crushing apparatus is controllable. It is also envisaged that the crushing apparatus 19 includes a blockage control system whereby the crushing means 14 may be stopped, and optionally rotated in a reverse direction, to release a blockage, or in an emergency situation.

Figure 4 illustrates an alternative embodiment in which, the crushing apparatus, now generally indicted as 100, forms part of, or is carried by, a vehicle 170.

The apparatus 100 may otherwise be substantially similar to the apparatus 10. e.. * .

In preferred embodiments, the crushing apparatus 10, * 25 100 is used to crush materials such as concrete slabs and concrete aggregate 220a. The concrete slabs 20 are crushed to form concrete aggregate 22 (shown in Figure 1) and the concrete aggregate 220a may be further crushed into smaller concrete aggregate 220b (shown in Figure 4) by reintroducing the aggregate 220a via the hopper 40. The crushing apparatus 10,100 is particularly suited to crushing concrete, or similar material, incorporating metallic elements, especially steel (or other metal) wire or rods (e.g. steel reinforced slabs). The drawings show, by way of particular example, hollow core concrete slabs 20 with steel wire 24 reinforcement. In this instance, the hollow concrete slabs 20 are crushed into concrete aggregate 22 and the steel wire 24 is separated (shown in Figure 1). The separated concrete aggregate 22 and steel wire 24 may then be recycled. It will be seen that the slabs 20 are fed to the crusher 14 such that the lengths of wire are substantially parallel with the direction of feeding. This facilitates the feeding of the wire, after crushing, beyond the crusher 14 and onto conveyor lOb. To this end, it is preferred that conveyors 30 and 7Db are substantially in line with one another.

During use of the crushing apparatus 10, 100, a concrete slab 20 is placed at or near the first end of the conveyor 30 and is transported by the conveyor 30 towards the drum 50. When the slab 20 reaches the second end of the conveyor 30, a first end of the slab 20, leaves the belt 30 and is directed into the crusher * 25 14. In particular, the first end of the slab 20 is S..

directed into the gap between the drum 50 and the first *:* plate 62. The drum 50 rotates in a first direction *:.*. (anticlockwise in Figure 2). The space between the drum 50 and plate 62 is adjusted and set using the adjusting means 80, such that the space is less than the width of the slab 20 but wide enough to let any steel wire 24 pass through. As a result, when the slab is fed between the drum 50 and plate 62, an impacting force is created against slab 20 by the crusher 14. The crushing action is facilitated by the presence of the teeth 52, 66 on the drum 50 and plate 62. The crushing action breaks down the slab 20 into aggregate 22 while leaving the wire 24 intact. The rotation of the drum 50 in the first direction directs the concrete aggregate 22 and steel wire 24 through the gap and towards the sorting/transporting means 16. The hexagonal cross section of the drum 50 causes the gap between the drum 50 and plate 62 to vary as it rotates.

Thus the cross sectional shape encourages the concrete aggregate 22 and wire 24 through the gap while also causing the aggregate to break down from larger to smaller pieces as they pass through the gap. The actions of the conveyor 30 and rotating drum 50 cause the slab 20 to be continually fed towards the crusher 14 and directed through the gap between the drum 50 and plate 62.

As the concrete aggregate 22 and wire 24 pass through S...

the crusher 14, the aggregate 22 and wire 24 fall, under gravity, towards the sorting/transporting means * 25 16. In the embodiment shown, the aggregate 22 falls directly onto the first end of the first conveyor 70a, while the steel wire 24 is directed onto the second conveyor 7Db. The wire 24 is encouraged onto the second conveyor belt 70b by the magnetic attraction between the steel wire 24 and magnetised belt 70b. The aggregate 22 and wire 24 are then transported away from the drum 50 by the respective conveyors 70a, 70b. The conveyors 70a, 70b may direct the material to a storage site or container (not shown). It is envisaged that, typically, the concrete slabs 20 will be crushed to form 50-60mm aggregate.

The ability to adjust the size of the gap between the drum 50 and the first plate 24 means that the crusher 14 can accept varying sizes of concrete slabs 20 with varying sizes of steel wire 24 reinforcement. The size of the gap is advantageously set such that an impacting force will be created against the slab 20 but that any reinforcement wire can easily pass thought the gap towards the sorting/transporting means 16.

In addition to concrete slabs, the crushing apparatus can crush concrete aggregate 220 as illustrated in Figure 4. In this instance, the concrete aggregate 220a is fed into the hopper 40 where it travels, under gravity, toward the second end and is fed into the crusher 14. The concrete aggregate 220a is fed from the hopper 40 into the gap between the drum 50 and second I...

plate 64. In the illustrated embodiment, the concrete aggregate 220a is directed by the chute 65. The mechanism for crushing concrete aggregate 220a is similar to that for crushing concrete slabs 20.

However in this instance, the drum 50 rotates in a second direction (clockwise as show in figure 2) to encourage the crushed aggregate 220a through the gap towards the sorting/transporting means 16. The aggregate 220 that passes through the gap between the drum 50 and second plate 64 then falls under gravity towards the first end of the first conveyor 70a where it is collected and is transported away from the crusher 14. The gap between the drum 50 and second plate 64 is adjustable depending on the size of the input aggregate 220a and the desired size of the output aggregate 220b. It is envisaged that the concrete aggregate 220a can be crushed typically from 50-300 mm pieces to 10 mm pieces.

Concrete aggregate 220a which has been crushed into smaller aggregate 220b may then be further passed thought the crushing apparatus 10 via the hopper 40 to be broken down into even smaller pieces by decreasing the size of the gap between the drum 50 and second plate 26.

If, during use, the crushing apparatus 10 becomes blocked a control system is provided for causing the drum 50 to stop rotating in the direction that created the blockage and instead to rotate in the opposite *** direction such that the blockage may be removed. When I...

the blockage is removed the drum 50 will then continue to rotate in the direction required to encourage the

S IS

*. 25 aggregate 220 through the grinding/crushing means 14. I. 55

: . In an alternative embodiment, only one of the crushing plates 62 is provided, the hopper 40 being positioned to deliver material between the plate 62 and the drum 50. In this embodiment, the drum 50 rotates in the same direction irrespective of whether it receives material from the hopper 40 or the conveyor 30.

The invention is not limited to the embodiment(s) described herein, which may be amended or modified without departing from the scope of the present invention. S. * *5* * S ***. * S. S. S * **

S S..

S *. S. S. S * S

S

* S....

S

Claims

CLAIMS: 1. A crushing apparatus comprising means for feeding the

apparatus with material to be crushed; and means S for crushing said material, wherein said crushing means comprises a rotatable drum and at least one crushing member in operative association with the drum to crush said material therebetween during use, said feeding means being arranged to deliver said material between said drum and said at least one crushing member.

2. An apparatus as claimed in Claim 1, wherein said at least one crushing member is movable towards and away from said drum.

3. An apparatus as claimed in Claim 1 or 2, wherein said at least one crushing member is pivotable about an axis that is substantially parallel with the rotational axis of the drum.

4. An apparatus as claimed in any one of Claims 1 to : *.* 3, wherein said at least one crushing member comprises S...

an obverse surface which faces said drum, a plurality *:*::* of teeth being provided on said obverse surface. * 25 **

5. An apparatus as claimed in Claim 4, wherein said S. *5 : teeth are arranged in at least one row extending in a direction substantially parallel with the rotational axis of the drum.

6. An apparatus as claimed in Claim 4 or 5, wherein said teeth extend along said obverse surface, preferably along substantially the entire obverse surface, in a direction substantially perpendicular with the rotational axis of the drum.

7. An apparatus as claimed in any one of Claims 4 to 6, in which said teeth are substantially triangular in transverse cross-section.

8. An apparatus as claimed in any preceding claim in which said at least one crushing member comprises a crushing plate.

9. An apparatus as claimed in Claim 8, wherein said at least one crushing member comprises an obverse surface face having at least two non-coplanar sections, each section facing said drum.

10. An apparatus as claimed in Claim 9 when dependent on Claim 3, wherein said at least one crushing member : . is pivotable about one of said sections to allow S...

movement the other of said sections towards and away from the drum. * S. * 25 S..

11. An apparatus as claimed in any one of Claims 1 to S. : 10, wherein said drum has a plurality of crushing surfaces, adjacent crushing surfaces being non-coplanar to define a respective ridge therebetween.

12. An apparatus as claimed in Claim 11, wherein said drum has a substantially polygonal, and preferably a substantially regular polygonal transverse cross-section.

13. An apparatus as claimed in any preceding claim, wherein a plurality of teeth are provided on the obverse surface of said drum.

14. An apparatus as claimed in Claim 13, wherein said teeth are arranged in at least one row extending in a direction substantially parallel with the rotational axis of the drum.

15. An apparatus as claimed in Claim 13 or 14, wherein said teeth extend along said obverse surface, preferably along substantially the entire circumference of the drum, in a direction substantially perpendicular with the rotational axis of the drum.

16. An apparatus as claimed in any one of Claims 13 to 15, in which said teeth are substantially triangular in S...

transverse cross-section. * .* * **

* 25 17. An apparatus as claimed in any one of claims 13 to 16 when dependent on Claim 4, wherein the teeth of the drum are laterally displaced with respect to the teeth of the at least one crushing member so that the respective teeth may be interlaced.

18. An apparatus as claimed in any preceding claim, wherein said feeding means comprises at least two separate feeding mechanisms, each feeding mechanism being arranged to deliver said material to said crushing means at a respective spaced apart location.

19. An apparatus as claimed in Claim 18, wherein said at least one crushing member comprises a respective crushing member for each feeding mechanism, the respective feeding mechanism being arranged to deliver said material between said drum and the respective crushing member.

20. An apparatus as claimed in Claims 18 or 19, wherein at least one of said feeding mechanisms comprises a conveyor, said conveyor preferably being pivotable about an axis substantially perpendicular to the direction in which material is conveyed in use by the conveyor.

21. An apparatus as claimed in any one of Claims 18 to 20, wherein at least one of said feeding mechanisms *...

comprises a hopper, especially a gravity-feed hopper. * ** ** S * *5

s 25 22. An apparatus as claimed in Claim 21 when dependent on Claim 20, including a first feeding mechanism S. ** : comprising a conveyor arranged to feed material to said crushing means in a first direction, said first direction preferably being substantially perpendicular with the rotational axis of the drum; and a second feeding mechanism comprising a hopper arranged to feed material to said crushing means in a second direction, the second direction being non-parallel with said first direction and preferably being substantially perpendicular with the rotational direction of the drum.

23. An apparatus as claimed in any preceding claim, further including first means for receiving material after crushing by said crushing means, said first receiving means being located below, in use, and substantially in register with, said drum in order to receive material falling from said drum during use.

24. An apparatus as claimed in any preceding claim, further including a first feeding mechanism comprising a conveyor arranged to feed material to said crushing means in a first direction; and second receiving means for receiving material after crushing by said crushing means, said second receiving means being located substantially in line with said first feeding mechanism on an opposite side of said drum. S...

25. An apparatus as claimed in Claim 24, wherein said second receiving means is arranged to be lower, in use, * ..

than said first feeding mechanism and, preferably, lower than said drum. S. *S * S

S S

26. An apparatus as claimed in any one of Claims 23 to 25, wherein said receiving means comprises a conveyor, optionally a magnetised conveyor.

27. An apparatus substantially as hereinbefore described with reference to the accompanying drawings. * *** I... * * *S.* * S. S. S *

..CLME: S *..

S S. *S *5 S * S

S

555 55. * S