Trash screen

Abstract

 A trash screen comprises a first screen (1) and a second screen (7), the second screen being pivotally mounted relative to the first screen, and means (13) for pivoting the second screen relative to the first screen.

Description

[0001] This invention relates to a trash screen.

[0002] A trash screen is generally in the form of a grille of spaced bars which prevent debris entering a culvert or drain which is intended to allow water, especially flood water, to flow away from a location.

[0003] A problem with conventional trash screens is that they allow debris to build up, which in flood conditions causes a water source, such as a ditch or watercourse, to back up because the water is unable to flow away into the culvert or drain as intended. This tends to exacerbate, rather than to alleviate, flooding problems.

[0004] It is therefore an object of the present invention to provide a trash screen which overcomes, or at least ameliorates, the above problem.

[0005] According to the present invention there is provided a trash screen comprising a first screen and a second screen, the second screen being pivotally mounted relative to the first screen, and means for pivoting the second screen relative to the first screen.

[0006] The first and second screens may each comprise a plurality of substantially parallel bars, the bars of the second screen lying between the bars of the first screen in one configuration of the first and second screen. The second screen may include means for preventing the parallel bars of the second screen passing through the first screen.

[0007] The means for pivoting the second screen may comprise motive means, which motive means may be selected from an electric motor, hydraulic, pneumatic and manual means. The pivoting means may include a lifting member between the motive means and the second screen. The lifting member may be selected from a lifting arm (which may be arcuate or linear), a cable and a chain.

[0008] Where an electric motor is provided, the motor and a battery therefor may be housed in a tamper-proof housing. The trash screen may include telemetry means for determining the state of charge of the battery, which telemetry means may include means for transmitting the state of charge of the battery to a remote control centre.

[0009] Telemetry means may be provided for determining whether the trash screen is blocked by debris and for actuating the means for pivoting the second screen so as to pivot the second screen relative to the first screen and to raise the debris from the first screen. The telemetry means may include means for transmitting to a remote control centre a notification that the second screen has been moved.

[0010] For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which:

[0011] Figure 1 is a diagrammatic illustration of part of a conventional trash screen;

[0012] Figure 2 is a plan view of one embodiment of part of a trash screen according to the present invention;

[0013] Figure 3 is a side view corresponding to Figure 2;

[0014] Figure 4 is a diagrammatic illustration of part of a trash screen according to the present invention in a first configuration; and

[0015] Figure 5 is a diagrammatic illustration of the part of the trash screen of Figure 4 is a second configuration.

[0016] Figure 1 shows a version of part of a conventional trash screen. The screen comprises a grille 1 formed of a plurality of parallel bars 3 which are supported by a smaller number of transverse bars 5 which are arranged behind the parallel bars 3. When water, especially flood water, passes through the screen the parallel bars 3 serve to prevent the passage of debris (known as "trash") into a waterway and therefore reducing the risk of blockage or contamination further down the waterway. However, in the event of a flood, the trash screen can rapidly become blocked with debris and in such an event does not allow water to pass through the screen. This can give rise to flooding in a location where the waterway is intended to relieve or prevent such an event.

[0017] Figures 2 and 3 show an additional screen 7 which in use is mounted on an existing trash screen, for example by welding or bolting. The screen 7 comprises a plurality of parallel bars 9 which are secured together by a number, that is at least two transverse bars. The transverse bars allow the parallel bars 9 to lie between, but not to pass through, the parallel bars 3 of the grille 1. One transverse bar 11 is arranged at a longitudinal end of the parallel bars 9 and is secured to the grille 1 by way of a hinge 13 which extends transversely of the parallel bars 9 so as to allow the screen 7 to pivot relative to the grille 1. A further transverse bar 15 is mounted at a distance from the first-mentioned bar 11 for maintaining the parallel arrangement of the bars 9.

[0018] The further transverse bar 13 is provided with means for pivoting the screen 7 relative to the grille 1 as will be explained in more detail hereinafter. Alternatively, the means for pivoting the screen 7 may be secured to one or more of the parallel bars 9.

[0019] The means for pivoting the screen 7 comprises a supporting member 17 mounted on the grille 1 for supporting operating means 19 for pivoting the screen 7 by way of a lifting member 21. The supporting member 17 may comprise a right-angle frame as shown in Figures 4 and 5 to which is secured an operating means in the form of an electric motor. However, in some embodiments of the invention the electric motor may be replaced by other lifting means such as pneumatic, hydraulic or manual lifting means. The lifting member is shown in Figures 4 and 5 as an arcuate lifting arm which engages with the lifting means, in particular with the electric motor, for lifting and lowering the screen 7 so as to cause the screen to pivot relative to the grille 1. However, the arcuate lifting arm may be replaced by other forms of lifting arm, such as a linear arm (which may be pivotally mounted to the screen 7 if desired) or a cable or lifting chain. The electric motor 19 may be powered by a battery 23 and both the motor and the battery may be housed in a tamper-proof housing.

[0020] The trash screen may additionally include a telemetry system (not shown) for determining the state of the battery for operating the motor 19 and for determining when the trash screen is blocked with debris (for example by determining water level). The telemetry means may include means for transmitting the state of charge of the battery and/or when the trash screen is blocked by debris to a remote control centre. In normal circumstances the trash screen will operate as a conventional trash screen. However, in the event that blockage of the trash screen is determined (for example by measuring water level, at least upstream of the trash screen), the motor 19 is activated to pivot the screen 7 relative to the grille 1 so as to raise the accumulated debris from the grille 1 and to allow water to flow through the grille into a culvert, drain, waterway or the like, thereby alleviating the problem of flooding in the immediate vicinity of the trash screen. At the same time, the telemetry system may send a message to a control station warning that the motor 19 has been actuated and that the trash screen needs to be cleared and the screen 7 replaced on the grille 1. Such a message will allow prioritisation of the clearing and collection of debris from the or each trash screen from which a message has been sent. Similarly, a message can be sent to the control station in the event the state of charge of the battery is determined to be inadequate.

Claims

1. A trash screen comprising a first screen (1) and a second screen (7), the second screen being pivotally mounted relative to the first screen, and means (13) for pivoting the second screen relative to the first screen.

2. A trash screen as claimed in claim 1, wherein the first and second screens (1, 7) each comprise a plurality of substantially parallel bars (3, 9), the bars of the second screen (7) lying between the bars (3) of the first screen (1) in one configuration of the first and second screen.

3. A trash screen as claimed in claim 2, wherein the second screen (7) includes means (11, 15) for preventing the parallel bars (9) of the second screen passing through the first screen (1).

4. A trash screen as claimed in any preceding claim, wherein the means (13) for pivoting the second screen (7) comprises motive means (19).

5. A trash screen as claimed in claim 4, wherein the motive means is selected from an electric motor (19), hydraulic, pneumatic and manual means.

6. A trash screen as claimed in claim 5, wherein an electric motor (19) is provided and the motor and a battery (23) therefor are housed in a tamper-proof housing.

7. A trash screen as claimed in claim 6 and including telemetry means for determining the state of charge of the battery (23).

8. A trash screen as claimed in claim 7, wherein the telemetry means includes means for transmitting the state of charge of the battery (23) to a remote control centre.

9. A trash screen as claimed in any one of claims 4 to 8, wherein the pivoting means (13) includes a lifting member (21) between the motive means (19) and the second screen (7).

10. A trash screen as claimed in claim 9, wherein the lifting member (21) is selected from a lifting arm, a cable and a chain.

11. A trash screen as claimed in claim 10, wherein an arcuate lifting arm (21) is provided.

12. A trash screen as claimed in claim 10, wherein a linear lifting arm is provided.

13. A trash screen as claimed in any preceding claim, wherein telemetry means is provided for determining whether the trash screen is blocked by debris and for actuating the means (13) for pivoting the second screen (7) so as to pivot the second screen relative to the first screen (1) and to raise the debris from the first screen (1).

14. A trash screen as claimed in claim 13, wherein the telemetry means includes means for transmitting to a remote control centre a notification that the second screen (7) has been moved.

Drawing