Mobile aggregate processing plant

1. A mobile aggregate processing plant for screening aggregate material comprising a mobile chassis, a vibrating screening unit mounted on the mobile chassis and able to provide at least one aggregate discharge stream therethrough, and an underscreen conveyor located wholly or substantially beneath the vibrating screening unit to wholly or substantially receive said at least one aggregate discharge stream,

wherein the underscreen conveyor is mounted to the mobile chassis so as to be moveable relative to the vibrating screening unit between a first position in use to work in co-operation with the vibrating screening unit, and at least a second position when not in use to provide an access portal below the vibrating screen unit, wherein in the first position the underscreen conveyor is positioned closer to the vibrating screen unit than in the second position,

wherein the underscreen conveyor has a first end and a second end, the first end being located at a lower vertical position relative to the mobile chassis than the second end so as to, when the underscreen conveyor is in the first position during use, convey aggregate material on the underscreen conveyor in an uphill direction from the first end to the second end in order to discharge the aggregate discharge stream at a vertical height above the mobile chassis that is higher at the second end than where the aggregate discharge stream is received on the underscreen conveyor, and

wherein the vibrating screening unit is driveable in the same longitudinal direction relative to the mobile chassis as the underscreen conveyor.

2. The mobile aggregate processing plant as claimed in claim 1 , wherein the underscreen conveyor is mounted on the mobile chassis independently of the mounting of the vibrating screening unit on the mobile chassis.

3. The mobile aggregate processing plant as claimed in claim 1 , wherein the mobile chassis has a main frame and a sub-frame, and the underscreen conveyor is mounted on the main frame, and the vibrating screening is mounted on the sub-frame.

4. The mobile aggregate processing plant as claimed in claim 1 , wherein the underscreen conveyor is vertically moveable relative to the vibrating screening unit between the operating and non-operating configurations.

5. The mobile aggregate processing plant as claimed in claim 1 , wherein the underscreen conveyor is laterally moveable relative to the vibrating screening unit between the operating and non-operating configurations.

6. The mobile aggregate processing plant as claimed in claim 3 wherein the vibrating screening unit comprises at least a series of upper screens and a series of lower screens, and a lower screen is removeable when the underscreen conveyor is in the second position.

7. The mobile aggregate processing plant as claimed in claim 1 , wherein the underscreen conveyor includes one or more wings to increase the aggregate discharge catchment area of the underscreen conveyor.

8. The mobile aggregate processing plant as claimed in claim 1 , further comprising a post-screening discharge conveyor located at least partly beneath the vibrating screening unit to receive at least some of the aggregate discharge stream from the vibrating screening unit.

9. The mobile aggregate processing plant as claimed in claim 1 , further comprising one or more of the group comprising: an aggregate feed hopper, an aggregate feed conveyor, one or more post-screening discharge conveyors.

10. A mobile aggregate processing plant comprising:

a mobile chassis having tracked mobility;

an aggregate feed hopper to receive aggregate material;

an aggregate feed conveyor to transfer the aggregate material to a vibrating screening unit;

a vibrating screening unit having an aggregate feed end and a discharge end, the aggregate feed end being higher than the discharge end relative to the mobile chassis, and comprising at least two screens drivable to screen the aggregate material into at least two different aggregate discharge streams of different particle sizes, at least one of which is discharged directly through the vibrating screening unit;

an underscreen conveyor wholly or substantially located beneath the vibrating screening unit to receive the aggregate discharge stream discharged through the vibrating screening unit;

one or more post-screening discharge conveyors able to convey a discharge stream from the vibrating screening unit to a different location;

wherein the underscreen conveyor is mounted to the mobile chassis so as to be moveable relative to the vibrating screening unit between a first position in use to work in co-operation with the vibrating screening unit, and at least a second position when not in use to provide an access portal below the vibrating screen unit, wherein in the first position the underscreen conveyor is positioned closer to the vibrating screen unit than in the second position,

wherein the underscreen conveyor has a first end and a second end, the first end being located at a lower vertical position relative to the mobile chassis than the second end so as to, when the underscreen conveyor is in the first position during use, convey aggregate material on the underscreen conveyor in an uphill angle relative to the mobile chassis from the first end to the second end in order to discharge the aggregate discharge stream at a vertical height above the mobile chassis that is higher at the second end than where the aggregate discharge stream is received on the underscreen conveyor.

11. The mobile aggregate processing plant as claimed in claim 10 having either at least one post-screening discharge conveyor extending in a non-parallel direction to the mobile chassis and vibrating screening conveyor, or one or two post-screening discharge conveyors extending laterally to the mobile chassis and vibrating screening conveyor, or both.

12. The mobile aggregate processing plant as claimed in claim 1 , able to be located within an ISO high cube container.

13. A method of servicing a mobile aggregate processing plant for screening aggregate material comprising the steps of:

providing a mobile chassis, a vibrating screening unit mounted on the mobile chassis, and an underscreen conveyor at least partly located beneath the vibrating screening unit, wherein the underscreen conveyor is mounted to the mobile chassis so as to be moveable relative to the vibrating screening unit between a first position and at least a second position, wherein in the first position the underscreen conveyor is positioned closer to the vibrating screen unit than in the second position;

moving the underscreen conveyor between a first position to work in cooperation with the vibrating screening unit in use, and at least a second position able to provide an access portal below the vibrating screen unit when not in use; and

accessing the vibrating screen unit from below.

14. The mobile aggregate processing plant as claimed in claim 1 , wherein the vibrating screening unit has an aggregate feed end positioned to receive a stream of aggregate material, and a discharge end for discharging aggregate material that has not passed through the vibrating screening unit, and wherein when the underscreen conveyor is in the first position, the spacing between the discharge end of the vibrating screening unit and the second end of the underscreen conveyor is less than the spacing between the aggregate feed end of the vibrating screening unit and the first end of the underscreen conveyor.