AU739694B2 - Trap for solid waste - Google Patents

Description

-1- P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: TRAP FOR SOLID WASTE The following statement is a full description of this invention, including the best method of performing it known to us: GH REF: P50819B/BJN -2- TRAP FOR SOLID WASTE The present invention is concerned with a trap for solid matter and, more particularly, a trap for solid matter for use in a stormwater pit.

Pollution of waterways by stormwater is a major problem in most large cities, particularly those where the stormwater runs into a relatively restricted waterway such as a river or bay which may also be used for recreation purposes. Not only does rainwater falling onto city streets collect small particulate matter such as dust, it also carries larger items such as litter into the stormwater drainage system which is present in all major cities. Such systems comprise a plurality of entry points which each have a stormwater pit, an inlet to the pit and an outlet from the pit, and a stormwater drainage system.

The inlet may be the mouth of the pit covered by a grate or a restricted orifice into which water is channelled such as in modern kerb and channelling systems. Small particulate matter and small pieces of litter can be carried into either system, and even large pieces of litter can be carried into modern kerb and channelling systems since the restricted orifice is still relatively large and generally 25 -does not have a grate which would otherwise serve to prevent entry of these large pieces of litter.

Accordingly, in a conventional system solid matter is carried from the surface into the stormwater pit and then into the stormwater drainage system, with the result that it is carried ultimately into the city's waterways. Small particulate matter will often deposit in the waterways and so they "silt up" over time, and litter items may be washed back onto beaches or other areas set aside for recreation. Marine life such as dolphins and turtles can become entangled in certain litter items and this can cause injury or death to the animal. Accordingly, C:\Eudora\P50819B.doc 27/04/99 S- I..

3 there is a need for solid matter such as litter and silt to be removed from stormwater prior to its discharge into waterways.

According to the present invention there is provided a trap for litter suitable for use in a stormwater pit, including a stormwater-receiving receptacle having a substantially water impermeable base and at least one upright wall which together form said receptacle, and inlet means for stormwater; said receptacle having a first zone adjoining a first wall section and beneath it a second zone bounded by a second wall section which is substantially water impermeable, the junction of the first and second zones, and the base of said receptacle; said receptacle being arranged so as to 15 be received in a stormwater pit in an orientation wherein stormwater enters said receptacle through said inlet means and is directed to said second zone where it is retained to allow for fine particulate matter to settle from the stormwater; said first wall section having a plurality of perforations formed therein which act as an outlet for stormwater overflowing from said second zone into said •first zone but do not allow the passage of litter from the ooeo trap.

It will be appreciated that stormwater carrying 25 solid matter such as silt and litter entering said second zone collects in the second zone until it overflows into the first zone. Silt in the stormwater settles within the second zone and some litter will sink also. Any litter which floats is prevented from leaving said first zone provided it is larger than the dimensions of the perforations formed in said first wall section, and these are typically chosen to retain quite small pieces of litter.

It will be appreciated that the initial flow of stormwater into a stormwater pit carries with it most of the solid matter, so a diversion system can be employed to divert only the initial run off into the trap described above.

Typically when stormwater enters the stormwater pit it either runs through a grate or enters through a restricted orifice in a kerb and channelling system and drops into the stormwater pit. In preferred embodiments of the invention the trap for solid matter is received within the stormwater pit and is configured in approximately the same shape as the stormwater pit with slightly lesser dimensions so that it fits within the pit.

Typically, water falling into the stormwater pit falls into the trap. Water falling into the trap is directed to said second zone, often through said first zone. Typically, direction of the water to the second zone occurs merely by the orientation of the trap such that water falls into said second zone. Water falling into said second zone may fall through said first zone but should not strike the first wall section directly in significant amounts since silt carried in the water could pass directly through the perforations and be carried into the stormwater.

25 Typically said receptacle includes an upper first zone and a lower second zone, each occupying the entire area bounded by said first wall section and said second wall section, respectively, wherein said first wall section and said second wall section extend completely around the wall of the receptacle. In the alternative, the first wall section may extend only part way around the receptacle.

Typically, the receptacle has four walls and is generally square or rectangular in shape, and the walls may be supported by a framework. However, the receptacle may be any suitable shape, for example round, in which case it has only one wall. In each case any reference to the first C:\Eudora\P50819B.doc 27/04/99 5 wall section or the second wall section is to be taken as a reference to a section of the entire wall area of the receptacle, including or excluding the framework, as appropriate, not to a section of any one particular side wall of a receptacle which is other than round.

Typically said second wall section is a solid plastic molding or made of sheet metal. Typically said first wall section is made of a mesh, such as a plastic mesh or steel mesh.

Preferably, said second zone extends S"approximately one quarter to one third of the distance up the or each wall of the receptacle, and extends the same 15 distance up each side wall of a receptacle which is other than circular in shape.

Typically, the perforations in the mesh material are approximately 5 to 30 mm square.

In a preferred embodiment of the invention, the receptacle is mounted on upright legs which rest upon the :base of the stormwater pit in situ, and hence keep the base of the trap spaced apart from the base of the stormwater 25 pit. Also, the walls of the receptacle are spaced apart from the walls of the stormwater pit as described above, hence water can drain out of the trap and to the base of the stormwater pit, where it may flow beneath the trap to an outlet if necessary.

In a particularly preferred embodiment of the invention the trap includes coupling means by which it is lifted out of the stormwater pit. Typically, said coupling means comprise a shackle on the end of an arm which is moveable from an operational configuration, in which the trap rests within the stormwater pit and performs the function described above, to a lift S I configuration.

Typically there are two arms, one to either end of a rectangular trap.

Preferably, the arms are hingedly mounted to the trap, more particularly to a frame member which forms a portion of the framework which forms each side of a generally rectangular trap, and each is slidable within said frame member (once pivoted from the horizontal orientation they take up in the operational configuration to the vertical position), to a locked position. In general, this involves sliding into a retaining bracket.

S Once in the locked position, which can only be achieved with the grate removed, a forklift or other lifting device lifts the trap from the stormwater pit.

o°*o S"Typically this is achieved by the forklift inserting its lifting prongs into the shackles described above and then moving said prongs in a vertical direction until the trap clears the stormwater pit, whereupon the forklift is driven to a place where it is desirable to empty the trap.

In a particularly preferred embodiment of the oo invention, the base of the receptacle is hinged and can be 25 opened to release the contents of the receptacle.

Typically, said base is held in the closed position by latch means. Conveniently, the latch means comprises a mechanical linkage held in a latched configuration by a clip including a catch which engages a nib on said base.

When the clip is removed the mechanical linkage can be actuated and the catch disengages from the nib, allowing the base to pivot from a closed configuration to an open configuration whereby the contents of the receptacle are dumped.

Throughout this specification and the claims, the words "comprise", "comprises" and "comprising" are used in CAEudoraT\P50819B.doc 27/04/99 a non-exclusive sense.

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying Figures, in which: Figure 1 is a perspective view of apparatus in accordance with the present invention in the operational configuration; Figure 2 is a perspective view of the apparatus shown in Figure 1 in the lift configuration with the base :opened to release the contents of the receptacle; "O 15 Figure 3 is a front elevation of apparatus in o* 2. accordance with the present invention showing the apparatus both in the operational configuration and the lift configuration; Figure 4 is a plan view of the apparatus shown in Figure 3 with one arm in the lift configuration and one arm in the operational configuration; Figure 5 is a side elevation of the apparatus 25 shown in Figure 3 in the lift configuration; and Figure 6 is a view similar to Figure 5 with the base opened to release the contents of the receptacle.

The apparatus illustrated in the Figures is a trap 10 for solid waste, adapted for positioning within a stormwater pit. The trap 10 includes a stormwaterreceiving receptacle 11 comprising a base 12 and four upright walls 13, 14, 15, 16 held together by a framework, generally designated 17 and including frame members 18, 19, 21, which will be referred to specifically hereafter.

The trap 10 also includes inlet means for stormwater, in C:\Eudora\P50819B.doc 27/04/99 -8this case comprising the open top 22 of the trap The trap 10 has a first zone adjoining a first wall section and beneath it a second zone defined by a second wall section, its junction with said first zone and the base 12 of said receptacle. The first wall section comprises four mesh sections 23, 24, 25, 26 and the first zone in this case is the region within the receptacle 11 surrounded by the mesh sections 23, 24, 25, 26. The bottom one third of the receptacle 11 comprises a second wall section, which consists of solid panels 27, 28, 29, The second zone is the area within the receptacle 11 above the base 12 but beneath an imaginary junction between the first zone and the second zone, which may be considered as 15 a flat surface aligned with the top of each of the panels 27, 28, 29, 30. It will be appreciated that water entering the trap 10 falls through its open top 22, through the first zone, and onto the base 12. Since the panels 27, 28, 29, 30 and base 12 do not allow the passage of water, nor of solid matter, stormwater collects in the second zone 0:9. until it overflows into the first zone. While the stormwater is building up in the second zone most or all of the silt in the water settles onto the base 12. However, some litter will float up to within the first zone but then 25 cannot pass through the perforations in the mesh sections 00 23, 24, 25, 26, and so is retained within the receptacle 11.

The trap 10 is mounted on upright legs 31, 32, 33, 34 which serve to keep the base of the trap 10 spaced apart from the base of the stormwater pit. This allows stormwater overflowing the trap 10 to flow beneath it to an outlet, if this is necessary.

The trap 10 further includes coupling means, in this case arms 35, 36, each of which has a shackle 37, 38 formed on its end. The opening 39, 40 in each shackle is C:\Eudora\P50819B.doc 27/04/99 adapted to receive a fork of a forklift truck.

It will be noted that each of the arms 35, 36 is hingedly mounted on the framework, in this case on frame members 18, 19, respectively, and can be pivoted from the operational position shown in Figure 1 to an upright position. Each arm 35, 36 can then be slid along each of frame members 18, 19 until they engage a retaining bracket 41, 42 respectively. Once each of the arms 35, 36 is locked in the relevant retaining bracket 41, 42, the trap is in the lifting configuration shown in Figure 5. The base 12 of the receptacle 11 may then be opened to dump contents of the receptacle 11, but it will be appreciated this will only be done once the trap 10 has been lifted out of the stormwater pit and removed to a desirable location for dumping its contents.

It will be noted that the base 12 is held in the closed position by latch means. The latch means includes :20 mechanical linkage 43 comprising a plurality of pivotally linked levers with a catch 44 at the end of one of the terminal levers. The catch 44 engages nib 45 on base 12 to hold it in the closed position. At the other terminal end of the mechanical linkage 43, a slidable clip 46 engages a 25 tab 47 on the end of the lever. Clip 46 lies on handle 48 attached to frame member 20. The tab 47 may be slid out of engagement with clip 46, whereupon the lever is released and can be actuated. The resultant pivotal motion releases catch 34 from nib 35 and so base 12 is freed to pivot to the open position.

In operation, the trap 10 is placed in a stormwater pit and water is allowed to drain through a grate or through a restricted aperture in a kerb and channelling system into the trap. As described previously, the stormwater drops into the second zone and collects therein to a point where it overflows through the mesh C:\Eudora\P5s0819B.doc 27/04/99 sections 23, 24, 25, 26. However, silt collects in the second zone and any litter which floats is prevented from leaving the first zone by the mesh. Thus, over time silt collects in the bottom of the receptacle and litter trapped within the receptacle also builds up.

When it becomes necessary to empty the trap the grate is opened or access is gained to the stormwater pit by raising a manhole or the like covering the stormwater pit. Each of the arms, 35, 36 is raised manually and slid into the locked position as described above. Thus, the trap 10 is brought from the operational of configuration shown in Figure 1 to the lifting configuration shown in Figure 2. A forklift truck is moved into an appropriate position and operated so that its prongs extend through orifices 39, 40 in shackles 37, 38.

Once in position, lifting commences and the trap 10 is lifted out of the stormwater pit. The forklift truck then drives to a convenient location where the latch means is 20 actuated in the manner described above to dump the contents of the trap. The base 12 is then lifted up to the closed configuration and the latch re-engaged, the trap 10 taken back to the locus of the stormwater pit and re-positioned within the pit. The arms 35, 36 are folded back down into 25 the operation of configuration and the grate or manhole closed to allow operation of the trap to recommence.

Variations and modifications of the invention will be apparent to those skilled in the art, and such variations and modifications are encompassed within the scope of the present specification.

e C:\Eudora\P50819B.doc 27/04/99

Claims (13)

1. A trap for litter suitable for use in a stormwater pit, including a stormwater-receiving receptacle having a substantially water impermeable base and at least one upright wall which together form said receptacle, and inlet means for stormwater; said receptacle having a first zone adjoining a first wall section and beneath it a second zone bounded by a second wall section which is substantially water impermeable, the junction of the first and second zones, and the base of said receptacle; said receptacle being arranged so as to be received in a stormwater pit in an orientation wherein stormwater enters said receptacle through said inlet means and is directed to said second zone where it is retained 15 to allow for fine particulate matter to settle from the stormwater; said first wall section having a plurality of perforations formed therein which act as an outlet for stormwater overflowing from said second zone into said first zone, but do not allow the passage of litter from 20 the trap.

2. A trap as claimed in claim 1 in which said first wall section is made of a mesh.

3. A trap as claimed in claim 2 in which said mesh is a plastic mesh or a steel mesh. 25

4. A trap as claimed in claim 3 in which the perforations in the mesh are approximately 5 to 30 mm square.

A trap as claimed in any one of claims 1 to 4 in which said second wall section is a solid plastic molding or made of sheet metal.

6. A trap as claimed in any one of claims 1 to 5 in which said second zone extends approximately one quarter to one third of the distance upset at least one upright wall.

7. A trap as claimed in any one of claims 1 to 6 further comprising coupling means by which the trap is lifted out of the stormwater pits.

8. A trap as claimed in claim 7 in which said A coupling means comprises one or more shackles each mounted on the end of an arm which is moveable from an operational 12 configuration, in which the trap rests within the stormwater pit, to a lift configuration.

9. A trap as claimed in claim 8 in which the or each arm is hingedly mounted to the trap and pivots from said operational configuration to an upright lift configuration.

A trap as claimed in claim 9 in which the or each arm is locked in the lift configuration through sliding the hinged base into a retaining bracket.

11. A trap as claimed in any one of claims 1 to 10 in which the base of said receptacle is hinged and can be opened to release the contents of said receptacle.

12. A trap as claimed in claim 11 in which the base is held in the closed position by latch means.

13. A trap for solid matter suitable for use in a stormwater pit, substantially as hereinbefore described with reference to the accompanying drawings. DATED this 28 th day of April 1999 ENVIRO SYSTEMS PTY LTD and TEKROM AUSTRALIA PTY LTD By their Patent Attorney o: GRIFFITH HACK o 0 0 0 C:\Eudora\P50819B.doc 28/04/99