WHITE, Roger (96 Miller Way, Brampton, Cambridgeshire PE28 4RS, GB)
CLAIMS
1. Apparatus for sorting mixed waste materials, comprising: a housing configured to be vibrated to assist sorting: a screen having an inlet end for receiving waste materials and an outlet end for discharging at least- some waste received at the inlet end, the screen being pivotally coupled adjacent the inlet end to a substantially horizontal axle mounted in the housing; and means for resiliently supporting the screen relative to the housing to encourage pivotal movement of the screen about the axle when the housing is vibrated; wherein the screen comprises a plurality of tines mounted at the inlet end and extending to the outlet end. 2. Apparatus according to ' claim 1, in which the resilient support means is located to at least one lateral side of the screen.
3. Apparatus according to claim 1 or claim 2, in which the resilient support means is located in between the inlet and outlet ends of the screen.
4. Apparatus according to claim 3, in which the resilient support means is located half to three quarters of the way along the screen from the inlet end.
5. Apparatus according to any one of the preceding claims, in which the resilient support means comprises a resilient component or member and a mount fixed to the housing for engaging the resilient component or member.
6. Apparatus according to claim 5, in which the resilient component or member is coupled to the mount or the screen. 7. Apparatus according to 'claim 5 or claim 6, in which the screen is configured to separate from at least part of the resilient support means during periods of use. 8. Apparatus according to claim 7, further comprising means for arresting movement of the tines when the screen has separated from at least part of the resilient support means .
9. Apparatus according to claim 9, wherein the arresting means comprises a stop fixed to the housing or a tether between the screen and the resilient support means.
10. An assembly for sorting mixed waste materials, comprising a first section comprising apparatus according to any one of claims 1-9, and a second section comprising apparatus according to, any one of claims 1-9, the second section being positioned downstream of the first section so that in use material discharged from the outlet end of the screen of the first section feeds the inlet end of the screen of the second section. 11. An assembly according to claim 10, wherein the tines of the screen of the first section are spaced further apart than the tines of the screen of the second section. |
TITLE: APPARATUS FOR SORTING WASTE MATERIALS
DESCRIPTION
The present invention relates to the sorting of waste materials, and more particularly to apparatus for classifying such materials.
More particularly, but not exclusively, the invention relates to the sorting of waste materials of the kind normally encountered in skips hired for domestic use. Such waste materials often comprise a mixture of earth from gardens, brick and concrete rubble from small building works, wood, scrap metal and general household refuse including paper, cardboard, light plastics packaging and broken glass. The nature of such skip waste is usually very different from that of household garbage which can be expected to be lighter in weight and to contain more wet vegetable and the like matter.
The present applicant's International application
WO98/42455 describes a method and apparatus for classifying waste materials, using two sieve screens, means for vibrating the screens and air blower means for blowing air in the space between the screens .
. The present applicant has devised an improved apparatus for sorting waste materials. The improved apparatus may be used in isolation as a stand-alone device for preliminary classification purposes, or may be incorporated into the apparatus described in WO98/42455 as an additional waste sorting component or even as a first section of one of the screens.
In accordance with the present invention, there is provided apparatus for sorting mixed waste materials, comprising: a housing configured to be vibrated to assist sorting; a screen having an inlet end for receiving waste materials and an outlet end for discharging at least some waste received at the inlet end, the screen being pivotally coupled adjacent the inlet end to a substantially horizontal axle mounted in the housing; and means for resiliently supporting the screen relative to the housing to encourage pivotal movement of the screen about the axle when the housing is vibrated, wherein the screen comprises a plurality of tines mounted at the inlet end and extending to the outlet end.
The tines are configured to allow waste materials below a predetermined size to pass through spaces between the tines. The remaining (larger) waste material is
encouraged to travel along the tines from the inlet end to the outlet by agitating the housing. The tines offer little or no resistance to such movement therealong. The tines may be configured to slope downwardly from the inlet end to the outlet end (at least when the housing is at rest) to encourage movement of waste materials along the screen.
The resilient support means may be located away from the tines, for example to one lateral side of the screen. For example, the screen may comprise an arm which pivots in sympathy with the tines and which is configured to engage the resilient support means, the arm being positioned to avoid interference with movement of waste material along the tines. Furthermore, the resilient support means may be located in between the inlet and outlet ends of the screen, perhaps half-way to three-quarters of the way along the screen from the inlet end. In this way, the free-ends of the tines may project beyond the resilient support means, helping to amplify physical movements of waste material at or near the outlet end when the housing is vibrated. The tines may even be constructed from a tough, resilient material such as spring steel to further amplify such movements .
The resilient support means may comprise a resilient component {e.g. a gas spring) or a resilient member {e.g. a coil spring or an elastomeric spring) and a mount fixed to the housing for engaging the resilient component/member . The resilient component/member may be coupled to the mount or to the screen. The screen may be configured to separate
from at least part of the resilient support means during periods of use. As heavy material approaches the outlet end, the free ends of the tines will increasingly deflect under the weight. Such deflection will increase the energy stored in the resilient support means. When the heavy material is discharged from the outlet end of the screen, the stored energy may be released suddenly, thrusting the free ends of the tines upwards with enough force to temporarily disengage at least part of the resilient support means. Such an action may be beneficial to waste material sorting as it will help to turn over waste material on the screen, bringing lighter material to the top and heavy materials to the bottom.
The apparatus may further comprise means for limiting or arresting upward movement of the tines. Such means may comprise a stop fixed to the housing, or even a tether. Such means may be configured to limit or arrest upward movement of the tines abruptly, further enhancing waste material sorting by helping to mix materials of different weights/densities.
The applicant believes that the present invention may speed up the sorting of waste materials, particularly when the waste materials include the likes of cardboard which have a tendency to stick to or become entangled with the tines and occlude the spacings therebetween.
An embodiment of the invention will now be described, by way of example, and with reference to the accompanying Figures in which:
Figure 1 is a schematic side view of apparatus for sorting waste materials according to an embodiment of the invention; and
Figure 3 is a partial, schematic perspective view of the apparatus of Figure 1.
In the drawings, there is shown an apparatus 10 for classifying waste materials, more particularly of the kind typically found in waste collection skips hired for domestic use, such waste materials typically comprising a mixture of garden earth, brick and concrete rubble, timber scrap metal and general household refuse including paper, light plastics packaging and broken glass.
The apparatus 10 comprises a housing 12 configured to be vibrated to assist sorting by means (not shown) known in the art. The apparatus 10 also comprises at least one screen 14 having an inlet end 16 for receiving waste material (e.g. from hopper 18) and an outlet end 20 for discharging at least some waste originally receive at the inlet end 16 and conveyed along screen 14 in direction- A. The remaining waste passes through screen 14 in direction B and onto a conveyor.
The screen 14 is pivotally coupled adjacent inlet end 14 to a substantially horizontal axle 30 mounted in housing 12. The apparatus 10 further comprises support means 40 including a coil spring 42 and mount 44 for resiliently supporting the screen 14 relative to the housing 12. The screen 14 comprises a plurality of tines 50 mounted at the inlet end 16 and extending so that their free-ends 52 form
the outlet end 20.
The resilient support means 40 is positioned to one lateral side of tines 50 so as not to interfere with waste movements. The screen 14 includes an arm 60 which moves in sympathy with tines 50. At rest, the arm 60 is configured to rest on resilient support means 40. However, the screen 14 is free to pivot about axle axis XX, and arm 60 is able to separate from resilient support means 40 if there is sufficient upward force on tines 50. Such an upward force may be generated by a sudden release of stored energy in the resilient support means, created, for example by the removal or discharge of a large mass from outlet end 20. A tether (not shown) may be provided to suddenly arrest upward movement of the tines 50. A second apparatus 14' may be positioned downstream of apparatus 14 to receive waste material discharged from outlet end 20. The second apparatus 14' operates in the same way as apparatus 14, but will have tines 50' with a closer spacing than tines 50.
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