AU1970301A - Soakage device - Google Patents

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Actual Inventor Address for service is: Helex Nominees (WA) Pty Ltd Alex Sarris WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR Invention Title: "Soakage Device" Details of Associated Provisional Application No(s): PQ5568 The following statement is a full description of this invention, including the best method of performing it known to me:- T -2-

TITLE

Soakage Device FIELD OF THE INVENTION The present invention relates to a soakage device for a drainage pit forming part of a drainage system.

BACKGROUND ART Drainage systems are provided by municipal authorities for drainage of water from roadways. These drainage systems have drainage pits to allow water entering the drainage system to soak through the base of the drainage pits into the underlying soil and enter the ground water. These drainage pits may, for example, be gully pits, side entry pits, combination side entry pits, manholes, soak wells and other types of drainage pits.

*Provision of such drainage pits in the drainage system allows water to soak into the ground beneath the drainage pit so that the drainage system does not have 15 to carry as much water. This provides for a more effective operation of the drainage system- since the volume of water which the system must handle is reduced.

*o a Typically, a hole is provided in the bottom of the drainage pit to allow water to soak into the ground. However, such holes frequently become blocked with 20 extraneous material, such as silt and refuse, which have entered the drainage system. When this occurs, the ability of the water to soak into the hole is inhibited. This means that rather than water soaking into the ground via the i holes in the drainage pits, the water is carried on in the drainage system thereby increasing the volume of water which the drainage system must handle. This can have disadvantageous consequences, e.g. it can result in the drainage system backing-up, overflowing or causing flooding.

-3- Removal of extraneous material blocking soakage in this way requires personnel to enter the drainage pit from a manhole at ground level. This is time consuming with the attendant risk of injury to personnel having to descend into the drainage pit.

DISCLOSURE OF THE INVENTION In accordance with one aspect of the present invention there is provided a soakage device for a drainage pit comprising filter means and a base provided beneath said filter means, wherein said filter means and said base allow passage of liquid therethrough and said filter means impedes passage of extraneous material therethrough, such that, in use, liquid is able to pass through said soakage device to beneath the floor of the drainage pit and passage of extraneous material is restrained by said filter means.

Preferably, said soakage device has silt trap means which is raised above the upper surface of said filter means and said silt trap means extends around the periphery of said upper surface of said filter means.

Preferably, said silt trap means projects upwardly above the said upper surface S•of said filter means.

The said silt trap means may be substantially rigid filter fabric.

Alternatively, the said silt trap means may be a fine mesh.

In one arrangement, the said filter means may sit on the base.

The said filter means may comprise at least one layer of filter medium.

The said filter means may comprise at least two layers of filter mediums that are able to trap extraneous material of different degrees of coarseness.

The said filter means may comprise at least two different filter mediums.

-4- In an alternative arrangement, the said filter means may be spaced from said base.

In this alternative arrangement, the filter means comprises sheet material of filter medium spaced from said base.

Preferably, pollutant absorbing substance is provided between said sheet material and said base.

Preferably, said pollutant absorbing material is activated carbon and/or charcoal.

The said sheet material may be attached to said silt trap means. Preferably, said filter means is provided in the form of a bag and the said sheet material forms the base of the bag and further sheet material of filter medium extends from said sheet material to form a side wall of said bag.

The said side wall may be attached to said silt trap means.

The said side wall may be attached to said base along the edge of said side wall that defines an opening of said bag.

15 The said sheet material and/or the said further sheet material may be a single sheet.

Alternatively, the said sheet material and the said further sheet material may be multiple sheets.

oo In each case, the silt trap means may, alternatively, be attached to said base.

0 20 Preferably, said filter medium is filter fabric.

Preferably, retention means is provided to, in use, retain said soakage device in position in the drainage pit.

The retention means may comprise at least one stake extending beneath said base and arranged to be driven into the soil beneath the floor of the drainage pit to anchor said soakage device and retain said soakage device in position in the drainage pit.

Alternatively, said retention means may comprise weighting said soakage device.

Preferably, the weighting of said soakage device is provided by weighting said base.

Preferably, said soakage device is provided with removal means to allow said soakage device to be removed from said drainage pit.

Preferably, said removal means is attached to said base.

Preferably, said removal means comprises an eye which is engageable from ground level, above the drainage pit, by hook means such that said soakage device may be lifted and thereby removed from said drainage pit.

In accordance with another aspect of the present invention there is provided a method of providing soakage in a drainage pit comprising forming an opening in the floor of the drainage pit and positioning a soakage device in said opening, said soakage device allowing passage of liquid therethrough and impeding passage of extraneous material.

In accordance with a further aspect of the present invention there is provided a method of providing soakage in a drainage pit comprising forming an opening in the floor of the drainage pit and positioning a soakage device as hereinabove described in said opening.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: -6- Figure 1 is a cross sectional elevation view of a first embodiment of a soakage device in accordance with one aspect of the present invention; Figure 2 is a cross sectional elevation view of the soakage device shown in Figure 1 in position in a first type of drainage pit; Figure 3 is an upper plan view of the drainage device and drainage pit shown in Figure 2; Figure 4 is a cross sectional elevation view of the soakage device shown in Figure 1 in position in a second type of drainage pit; Figure 5 is a top plan view of the soakage device and drainage pit shown in Figure 4; Figure 6 is a cross sectional elevation view of the soakage device shown in Figure 1 in position in a third type of drainage pit; Figure 7 is an upper plan view of the soakage device and drainage pit shown in Figure 7; Figure 8 is a cross sectional elevation view of a second embodiment of a soakage device in accordance with one aspect of the present invention in S:o• position in a first type of drainage-pit; Figure 9 is an upper plan view of the soakage device and drainage pit shown in Figure 8; Figure 10 is a cross-sectional elevation view of a third embodiment of a soakage device in accordance with one aspect of the present invention; Figure 11 is a cross-sectional elevation view of the.soakage device shown in Figure 10 in position in a first type of drainage pit; -7- Figure 12 is an upper plan view of the drainage device and drainage pit shown in Figure 11; Figure 13 is a cross-sectional elevation view of the soakage device shown in Figure 10 in position in a second type of drainage pit; Figure 14 is a top plan view of the soakage device and drainage pit shown in Figure 13; Figure 15 is a cross-sectional elevation view of the soakage device shown in Figure 10 in position in a third type of drainage pit; Figure 16 is an upper plan view of the soakage device and drainage pit shown in Figure Figure 17 is a cross-sectional elevation view of a fourth embodiment of a soakage device in accordance with one aspect of the present invention in position in a second type of drainage pit; and Figure 18 is an upper plan view of the soakage device and drainage pit shown Figure 17.

S"BEST MODE(S) FOR CARRYING OUT THE INVENTION In Figure 1, there is shown an embodiment of a soakage device 1 in accordance with the present invention. The soakage device 1 comprises a filter 2 and a base 3 provided beneath the filter 2.

The filter 2 sits on and covers the base 3. In this way, the base 3 supports the filter 2.

The filter 2 and the base 3 allow passage of liquid therethrough.

The filter 2 restrains passage of extraneous material therethrough.

-8- The filter 2 may be formed of one or more layers of filter medium.

The filter 2 may be multi-layer, made up of two or more layers of filter medium.

This is exemplified in Figure 1 where layers 4, 5, 6 and 7 of filter medium are shown.

The layers 4, 5, 6, and 7 offilter medium may have different grades of filtering capability.

Thus, for example, the layers 4, 5, 6 and 7 of filter medium may be provided such that each layer 4, 5, 6 and 7 is able to trap finer particles. In this way, the coarsest particles are filtered by layer 4 and progressively finer particles are filtered by the subsequent filters 5, 6 and 7 which are located progressively closer to the base 3.

As an alternative, layers 5, 6 and 7 may progressively filter finer particles and layer 4 may itself be a fine particle filter layer, i.e. filtering particles finer than layer 5 is capable of filtering.

go 15 The filter medium of the filter 2 may be filter fabric.

o The filter fabric may be provided in multiple pieces placed adjacent each other to form a layer/s of filter medium.

SIn the case of layers 4, 5, 6 and 7 of the filter medium, each layer 4, 5, 6 and 7 may itself be made up of multiple pieces of filter fabric forming each layer 4, 5, 6 20 and 7.

The base 3, for example, may be provided as a grating or mesh.

The base 3 is rigid.

The soakage device 1 is provided with a silt trap 8 which is raised above the upper surface 2a of the filter 2 and extends around the periphery thereof.

The silt trap 8 extends around the filter 2.

The silt trap 8 is attached to the base 3. This may be done by attaching the lower portion of the silt trap 8 to the periphery of the base 3.

The silt trap 8 comprises a filter medium to trap extraneous material.

The filter medium of the silt trap 8 may be rigid filter fabric. This rigid filter fabric may be provided in multiple pieces placed adjacent each other forming one or more layers of filter medium.

Alternatively, the filter medium may be provided as a fine mesh. However, a rigid filter fabric can be expected to be more effective in filtering finer particles in silt and so use of a rigid filter fabric is preferred.

The soakage device 1 is provided with a stake 9 to retain the soakage device 1 in position in the drainage pit in which it is installed. The stake 9 is attached to the base 3 by a plate 10 with one end of the stake 9 being attached to the plate and the plate 10 attached to the base 3.

15 A rod 11 extends upwardly from the base 3 and terminates in an eye loop 12.

The eye loop 12 enables the soakage device 1 to be removed from the drainage pit for maintenance.

:oooi The manner of installation and use of the soakage device 1 will now be described with reference to Figures 2 to 7 of the drawings.

o• Figures 2 to 7 of the drawings show the installation of a soakage device 1 in three different types of drainage pits 21, 22 and 23, respectively.

Each drainage pit 21, 22 and 23 has a shaft 24 and a floor 26. At least one pipe opens into the shaft 24. The shaft 24 extends from the floor 26 of the drainage pit 21, 22, 23 to ground level. Typically, the floor 26 is made of concrete.

The drainage pits 21, 22 and 23 form part of a larger drainage system (not shown). The direction of flow of the water into and out of the drainage pits 21, 22 and 23 is shown in the drawings by arrows F.

The soakage device 1 is installed in the drainage pit 21, 22, 23 by first forming an opening in the floor 26. The soakage device 1 is inserted into the opening so formed. The soakage device 1 is pushed into the hole such that the stake 9 is driven into the soil beneath the floor 26 to thereby anchor the soakage device 1.

This prevents the flow of water into the pit 21, 22, 23 dislodging the soakage device 1.

In an existing drainage pit 21, 22 or 23, the opening may be formed in the floor 26 by cutting through the floor 26. In the case of a new drainage pit under construction, an opening may be left in the floor 26 into which the soakage device may be positioned.

The soakage device 1 is installed such that the upper surface 2a of the filter 2 is substantially level with the upper surface 27 of the floor 26. The silt trap 8 extends above the upper surface 27 of the floor 26.

In use, water flowing through the drainage system flows through the pipes and passes intothe drainage pits 21, 22 and 23. As this water flows into the drainage pits 21 and 22, this water is also able to flow out of the respective 20 drainage pits 21 and 22 since inlet and outlet pipes 25 are provided. In drainage pit 23, only an inlet pipe 25 is provided.

As water flows into the drainage pits 21 and 22, the soakage device 1 allows water to pass therethrough and soak into the soil beneath the floor 26. This is because the filter 2 and base 3 allow passage of liquid therethrough.

•o.

In addition, any extraneous material 28, such as silt and refuse, entrained with the water and settling over the soakage device 1, is trapped by the filter 2 of the soakage device 1. Such extraneous material 28 either remains on the upper surface 2a of the filter 2 or is trapped within the filter 2. In addition, the silt trap 8 -11prevents extraneous material 29 entering the soakage device 1. This is because the silt trap 8 is raised above the level of the upper surface 2a of the filter 2 and the upper surface 27 of the floor 26. Thus, this extraneous material 29 does not need to be trapped by the filter 2 thereby reducing the amount of material required to be trapped by the filter 2 which reduces the maintenance required for the filter 2. Thus, the silt trap 8 repels extraneous material 29.

Since the drainage pits 21 and 22 have inlet and outlet pipes 25, water entering and then leaving the drainage pits 21 and 22 through these pipes 25 has a cleaning effect on the soakage device 1 since extraneous material 28 and 29 is flushed out of the drainage pits 21 and 22 and flows out through the outlet pipe In this way, the extraneous material 28, 29 is not retained in the drainage pits 21 and 22. This allows water to continue to soak through the soakage device 1 into the ground.

In the case of drainage pit 23, where only an inlet pipe 25 is provided, the flushing of water through the drainage pit 23 is not possible. In such a case, the soakage device 1 may need to be removed more frequently for maintenance.

Maintenance of the soakage device 1 is described below.

0o o The soakage -device 1 may be removed from the pits 21, 22 and 23 for maintenance by-inserting a hook device 30 through the eye 12, from ground level, and raising the soakage device 1 to ground level. Maintenance may be performed by using water to back flush the soakage device 1 such that the water passes from the base 3 through the filter 2 so that any extraneous material trapped in the filter 2 is removed therefrom. The soakage device 1 is then returned to its position in the floor 26 of the pit 21, 22 and 23 using the removal hook 30 in the eye loop 12 to lower the drainage device 1. Thus, it is not necessary for an operator to enter the shaft 24 for removal, maintenance, or °return of the soakage device 1.

Figures 8 and 9 show a soakage device 50 in accordance with a second embodiment, installed in a drainage pit 21.

-12- The soakage device 50 is similar to the soakage device 1 except in relation to the nature of the base. Accordingly, similar reference numerals have been used in Figures 8 and 9 for similar parts of the soakage device 1 used in Figures 1 to 7.

The soakage device 50 is provided with a base 52 of a weighted material which allows passage of liquid therethrough. The base 50 may be made of porous concrete. The lower portion of the rod 11 is embedded in the base 52.

The weighted base 52 ensures that the soakage device 1 is retained in position in the drainage pit 21 and is not dislodged by the flow of water through the pit 21.

Thus, the weighted base 52 avoids the need for a stake 9, as used in the soakage device 50 of the first embodiment, to retain the soakage device 50 in position.

In other respects, the soakage device 50 is similar to the soakage device 1.

It is also to be understood that the soakage device 50 may be used in pits 22 and 23 of the type shown in Figures 4 to 7 with reference to the soakage device 1.

oo The manner of installation and use of the soakage device 50 is similar to that of the soakage device 1 as previously hereinbefore described.

Figure 10 shows a third embodiment of a soakage device 60 in accordance with 20 the present invention.

The soakage device 60 is similar to the soakage device 1 except in relation to the nature of the filter 2A and provision of pollutant absorbing substance.

Accordingly, similar reference numerals are used in Figures 10 to 16 for similar parts of the soakage device 1 used in Figures 1 to 7.

-13- The soakage device 60 comprises a filter 2A in the form of sheet material 62 of filter medium. The base 3 is provided beneath the sheet material 62 and is spaced therefrom.

A pollutant absorbing substance 64 is provided between the sheet material 62 and the base 3 and spaces the sheet material 62 from the base 3.

The filter 2A may be provided as a bag with the sheet material 62 forming the bottom wall of the bag with a side wall, also made of sheet material 66, extending therefrom. The side wall terminates in an opening and the edge 68 of the further sheet material 66 at the opening is attached to the base 3. Thus, the bag is arranged in an inverted manner.

The sheet material 62 and 66 may comprise a single sheet or, alternatively, multiple sheets.

The filter medium of the filter 2A may be filter fabric.

The silt .trap 8 is attached to the further sheet material 66 that forms the side wall of the filter 2A. The silt trap 8 is of similar structure to the silt trap 8 described with reference to the first embodiment of the soakage device 1 with reference to Figures 1 to 7.

In an alternative arrangement, the silt trap 8 is attached to the base 3.

Alternatively, in a modified embodiment, the further sheet material 66 that forms i 20 the side wall may be omitted and the sheet material 62 is attached directly to the silt trap 8. The silt trap 8 is then attached to the base 3. However, this modified embodiment has not been shown in the drawings.

S So Figures 17 and 18 show a soakage device 70 in accordance with a fourth embodiment installed in a drainage pit 22.

-14- The soakage device 70 is similar to the soakage device 60 except in relation to the nature of the base that is used. In that regard, the base of the soakage device 70 is similar to the base 52 of the soakage device 50 of the second embodiment shown in Figures 8 and 9. Accordingly, similar reference numerals have been used in Figures 17 and 18 for similar parts of the soakage devices and 60 used in Figures 8 and 9, and Figures 10 to 16, respectively.

As with the soakage device 60, the silt trap 8 is attached to the further sheet material 66 that forms the side wall. The further sheet material 66 that forms the side wall of the soakage device 70 is attached to the weighted base 52.

Alternatively, the silt trap 8 is attached to the weighted base 52.

In a modified embodiment in which the further material 66 that forms the side wall is omitted and the sheet material 62 is attached to the silt trap 8, the silt trap 8 is then attached to the weighted base 52. However, this embodiment is not shown in the drawings.

In other respects, the soakage device 70 is similar to the soakage device It is also to be understood that the soakage device 70 may be used in drainage 99** pits 21 and 23 of the type shown in Figures 11 and 12, and 15 and 16 with reference to the soakage device The manner of installation and use of the soakage devices 60 and 70 is similar to that of the soakage device 1 as previously hereinbefore described except in relation to the operation of the pollutant absorbing substance.

.9 Thus, the filter 2A of the soakage devices 60 and 70 trap extraneous material 28, such as silt and refuse, entrained with the water travelling in the drainage pits 21, 9 99 22, 23 and which settles over the soakage devices 60 and 70. Such extraneous material 28 remains on the sheet material 62 of the filter 2A. In addition, the silt trap 8 prevents extraneous.material 29 from entering the soakage devices and In addition, in the event that the water passing through the sheet material 62 of the filter 2A contains pollutants, for example petrol and fuel based products, these pollutants are absorbed by the pollutant absorbing material 64 so that these pollutants do not enter the ground water beneath the drainage pit 21, 22, 23.

The pollutant absorbing material 64 may be activated carbon and/or charcoal.

In other respects, the soakage devices 60 and 70 function in a similar manner to the soakage devices 1 and 50 of the first and second embodiments described herein.

The soakage device of the present invention allows water entering the drainage system to soak into the soil beneath the floor of the drainage pit and into the ground water as required.

The soakage device of the present invention reduces the water load which the drainage system must handle and reduces the risk of the drainage system failing, 15 backing-up, overflowing and flooding roads. It also reduces the total volume of water that the drainage system has to handle and reduces the storage volumes required in drainage sumps, detention basins or compensation basins.

The soakage device of the present invention also reduces the drainage water :,o i level in trapped drainage pits by allowing them to dry out. This, in turn, reduces the amount of mosquito breeding in stagnant water and reduces the risk associated with children entering drainage systems that constantly contain water.

The soakage device of the present invention may be used in any areas where S• water is required to be disposed of into the underground water system, including soak wells in the building industry for residential, industrial and commercial uses.

The soakage device of the present invention may be used in gully pits, side entry pits, combination side entry pits, drainage manholes, soak well pits, bubble-up pits, compensating basins, drainage sumps and all other types of drainage pits.

-16- Modifications and variations such as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

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Claims (27)

1. Soakage device for a drainage pit comprising filter means and a base provided beneath said filter means, wherein said filter means and said base allow passage of liquid therethrough and said filter means impedes passage of extraneous material therethrough, such that, in use, liquid is able to pass through said soakage device to beneath the floor of the drainage pit and passage of extraneous material is restrained by said filter means.

2. Soakage device according to claim 1, wherein said soakage device has silt trap means which is raised above the upper surface of said filter means and said silt trap means extends around the periphery of said upper surface of said filter means.

3. Soakage device according to any one of the preceding claims, wherein silt trap means projects upwardly above the said upper surface of said filter means. C. @0 15 4. Soakage device according to any one of the preceding claims, wherein the e g. said silt trap means is substantially rigid filter fabric. 0

5. Soakage device according to any one of claims 1 to 3, wherein the said silt trap means is a fine mesh. oo•6 0

6. Soakage device according to any one of the preceding claim, wherein the said filter means sits on said base. sees S. ••QO

7. Soakage device according to claim 6, wherein the said filter means comprises O. at least one layer of filter medium. C

8. Soakage device according to claim 7, wherein the said filter means comprises at least two layers of filter mediums that are able to.trap extraneous material of different degrees of coarseness. -18-

9. Soakage device according to claim 7 or 8, wherein the said filter means comprises at least two different filter mediums. device according to any one of claims 1 to 6, wherein the said filter means is spaced from said base.

11.Soakage device according to claim 10, wherein said filter means comprises sheet material of filter medium spaced from said base.

12.Soakage device according to claim 11, wherein pollutant absorbing substance is provided between said sheet material and said base.

13.Soakage device according to claim 12, wherein said pollutant absorbing material is activated carbon and/or charcoal.

14.Soakage device according to any one of claims 11 to 13, wherein the said sheet material is attached to said silt trap means. device according to claims 11 to 14, wherein said filter means is provided in the form of a bag and the said sheet material forms the base of the 15 bag and further sheet material of filter medium extends from said sheet material to form a side wall of said bag.

16.Soakage device according to claim 15, wherein the said side wall is attached to said silt trap means.

17.Soakage device according to any one of claims 13 to 16, wherein the said side wall is attached to said base along the edge of said side wall that defines an opening of said bag.

18.Soakage device according to any one of claims 1 to 16, wherein said silt trap is attached to said base. -19-

19.Soakage device according to any one of claims 11 to 17, said sheet material and/or the said further sheet material is a single sheet. device according to any one of claims 11 to 17, wherein the said sheet material and/or the said further sheet material may be multiple sheets.

21.Soakage device according to any one of the preceding claims, wherein said filter medium is filter fabric.

22.Soakage device according to any one of the preceding claims, wherein retention means is provided to, in use, retain said soakage device in position in the drainage pit.

23.Soakage device according to claim 22, wherein said retention means comprises at least one stake extending beneath said base and arranged to be driven into the soil beneath the floor of the drainage pit to anchor said soakage device and retain said soakage device in position in the drainage pit.

24.Soakage device according to claim 22, wherein said retention means 15 comprises weighting said soakage device.

25.Soakage device according to claim 24, wherein said weighting of said soakage device is provided by weighting said base.

26.Soakage device according to any one the preceding claims, wherein said soakage device is provided with removal means to allow said soakage device "20 to be removed from said drainage pit.

27.Soakage device according to claim 26, wherein said removal means is attached to said base.

28.Soakage device according to any one of claim26 or 27, wherein said removal means comprises an eye which is engageable from ground level, above the 0 13 drainage pit, by hook means such that said soakage device may be lifted and thereby removed from said drainage pit.

29.A method of providing soakage in a drainage pit comprising forming an opening in the floor of the drainage pit and positioning a soakage device in said opening, said soakage device allowing passage of liquid therethrough and impeding passage of extraneous material. method of providing soakage in a drainage pit comprising forming an opening in the floor of the drainage pit and positioning a soakage device as defined in any one of the claims 1 to 28 in said opening.

31.Soakage device substantially as hereinbefore described with reference to Figures 1 to 7; 8 and 9; 10 to 16; and 17 or 18 of the accompanying drawings.

32.A method of providing soakage in a drainage pit substantially as hereinbefore described. Dated this twelfth day of February 2001. Helex Hominees (WA) Pty Ltd Applicant SWray Associates Perth, Western Australia Patent Attorneys for the Applicant *i