AU2003204241A1 - Sink filter - Google Patents

Description

I- I Regulation 3.2 Revised 2/98

AUSTRALIA

Patents Act, 1990

ORIGINAL

COMPLETE SPECIFICATION TO BE COMPLETED BY THE APPLICANT NAME OF APPLICANT: Cong An Dang ACTUAL INVENTOR: Cong An Dang ADDRESS FOR SERVICE: Peter Maxwell Associates Level 6 Pitt Street SYDNEY NSW 2000 INVENTION TITLE: SINK FILTER DETAILS OF ASSOCIATED PROVISIONAL APPLICATION NO(S): PS2376 17 May 2002 AU The following statement is a full description of this invention including the best method of performing it known to me:m:\docs\20031015\034364.doc The present invention relates to a filter for use in sinks of kitchens, laundries, bathrooms and the like, and also to a filter and plug assembly.

In most domestic sinks, a filter (also known as a strainer) is used to prevent food or other particulate matter above a predetermined size from passing through the sink drain hole and entering the drain where it might lead to blockage. Conventional dish shaped filters are dimensioned to seat snugly, but removably, in the drain hole and they include a plurality of usually circular apertures suitable for allowing liquid and only particulate matter below the predetermined size to pass therethrough. Particulate matter above the predetermined size will be trapped by the filter and will slow the rate at which liquid is drained from the sink. A problem arises in cases where the filter becomes so clogged with particulate matter that it blocks liquid drainage from the sink and removal of the particulate matter from the filter will then be required to restore drainage.

Another feature of most domestic sinks is the requirement to remove the filter to enable a plug to be fitted in the drain hole for the purpose of filling the sink with liquid, such as when items are to be immersed in a cleaning solution.

The removal of the filter from the drain hole to allow the plug to be used occasionally leads to the problem of the filter being misplaced or lost.

It is an object of the present invention to provide a sink filter that will not become clogged with particulate matter in normal use of a sink, and/or will require removal of particulate matter from the filter to restore drainage much less frequently than convention filters.

It is another, but merely preferred, object of the present invention to provide a sink filter and plug assembly that will avoid the need to remove the filter from the sink drain hole when it is desired to plug the drain hole.

According to the invention there is provided a filter for use in a sink, comprising:a filter body, means for engaging the filter body over a drain hole of the sink, and a plurality of holes formed through the filter body for allowing liquid to drain therethrough but trapping particulate matter, wherein the holes are so spatially arranged to provide at least two vertically spaced apart drain paths for the liquid, wherein when a first drain path becomes clogged with trapped particulate matter, at least a second drain path located above the first drain path continues to allow liquid to drain therethrough.

Preferably, the filter body includes an elevated portion through which the holes providing at least the second drain path are formed.

The holes are preferably vertically extending slots formed through one or more side walls of the elevated portion, wherein the first drain path is through a bottom region of each of the slots and the second drain path is through a region of each of the slots above the bottom region.

It is preferred that the elevated portion has a maximum height which is above a bottom surface of the sink surrounding the drain hole.

In a preferred form, the filter body includes a depressed portion that has a maximum depth which is below a bottom surface of the sink surrounding the drain hole, and the elevated portion is located centrally of the depressed portion.

Preferably, the depressed portion has a plurality of horizontally extending slots formed therethrough.

It is preferred that the elevated portion includes a plurality of holes formed through a top wall thereof.

According to another aspect of the invention, there is provided a filter and plug assembly for use in a sink, comprising the aforementioned filter and a plug adapted to be coupled to the filter when the filter is fitted in a drain hole of the sink so as to prevent liquid draining therethrough.

In order that the invention may be readily understood and put into practical effect, reference will now be made to the accompanying drawings, in which:- Fig 1 is a perspective view of a sink filter according to a preferred embodiment of the invention, Fig 2 is a sectional side view of a drain hole portion of a sink, showing the filter of Fig 1, in normal use, fitted over a drain hole and also showing the drain hole fittings, Fig 3 is a perspective view of a disassembled sink filter and plug assembly according to a preferred embodiment of another aspect of the invention, showing the filter of Fig 1 disassembled from a plug to which it can be coupled, Fig 4 is a perspective view of the sink filter and plug assembly of Fig 3, as assembled, and Fig 5 is a sectional side view of the sink filter and plug assembly shown in Fig 4.

The sink filter 10 consists of a filter body 12 and an annular rim portion 14 for engaging the body 12 over a drain hole 16 of a sink. The body 12 has a depressed portion 17 and an elevated portion 18 with a side wall 19 and a top wall There are a plurality of holes, in the shape of both rectangular slots 21a, 21 b and circular apertures 22, formed through the body 12 for allowing liquid 24 to drain therethrough but trapping particulate matter 26, such as food scraps. Horizontally extending slots 21a are formed in a mutually radially outward direction through the depressed portion 17. Vertically extending slots 21b are formed through the side wall 19 of the elevated portion 18. Circular apertures 22 are formed through the top wall 20 of the elevated portion 18.

The size of the holes (or openings) through the body 12 provided by the slots 21a, 21b and apertures 22 should be such as to allow particulate matter of no larger than about 2 mm optimal width to pass therethrough.

A plurality of vertically spaced apart drain paths are thus provided for the liquid to drain through the body 12 at all times of normal use of the filter 10. A first or lower drain path may be provided through a bottom region of each of the vertically extending slots 21b and a second or upper drain path may be provided through an upper region of each of those same slots 21 b above the lower drain path. These two vertically spaced apart drain paths arise by virtue of the vertically extending, spatial arrangement of each of the slots 21 b, and in the event that the lower drain path becomes clogged with trapped particulate matter, thereby obstructing or preventing liquid drainage through the lower drain path, liquid will continue to drain through the upper drain path (as shown by the darkened arrows in Fig 2).

The top wall 20 of the elevated portion 18 has a maximum height which is above the bottom surface 27 of the sink surrounding the drain hole 16, and the depressed portion 17 has a maximum depth which is below the sink bottom surface 27. The elevated portion 18 is a centrally located, cylindrically shaped, extension from the depressed portion 17. The depth of the depressed portion 17 is selected so as to create an annular groove between the upright annular wall 25 of the rim portion 14 and the side wall 19 of the elevated portion 18, the groove having a volume that can trap and retain an amount of particulate matter normally encountered by the user, say, during washing up of dishes in the sink. The height of the elevated portion 18 is selected so as to allow a sufficient number of holes of the filter 10 to remain open for liquid drainage even when a substantial amount of particulate material is trapped and retained in the annular groove. In that instance, those holes that remain open are the circular apertures 22 formed through the top wall 20 of the elevated portion 18 and the upper regions of each of the vertically extending slots 21b.

The height of the elevated portion 18 is also such as to provide a user with sufficient purchase to be able to easily grab the elevated portion 18 for lifting the filter 10 from the drain hole 16, say, for sink and filter cleaning purposes.

Each vertically extending slot 21b has an aligned horizontally extending slot 21a which meet at the junction of the depressed portion 17 and the elevated portion 18. The aligned slots 21a, 21 b are not continuous where they meet but are separated by a reinforcing rib member 28 across their meeting ends to strengthen the junction.

The filter 10 is, in this instance, made of moulded plastic, but can be made of stainless steel or other suitable material.

The filter 10 (when any trapped particulate matter is removed therefrom) is adapted for coupling to a plug 30 when it is desired to prevent liquid 24 passing through the drain hole 16 without first removing the filter 10 from its fitted position therein. When so coupled, the plug 30 provides a liquid seal against the filter The plug 30 has a disc portion 32, a button or knob portion 34 extending upwardly and centrally from the disc portion 32, and an annular skirt portion 36 extending downwardly from the disc portion 32. The outer annular part of the underside of the disc portion 32 is adapted to sit flat upon the upper side of the rim portion 14 of the filter 10 (as shown in Fig The outer side of the annular I- I skirt portion 36 snugly abuts against a top part of a side wall 29 of the rim portion 14 so that the plug 30 is reliably located on the filter 10 with no or insignificant sideways movement of the plug 30 with respect to the filter 10 and for liquid sealing to occur (as shown in Fig The knob portion 34 is cylindrically shaped and has an annular side wall 37 and a top wall 38 that define a cavity 39 therebetween. The cavity 39 is of sufficient dimension to receive therewithin an upper part of the elevated portion 18 by snug engagement of the side wall 37 of the knob portion 34 against the side wall 19 of the elevated portion 18.

The height of the knob portion 34 is also such as to provide a user with sufficient purchase to be able to grab the knob portion 34 for lifting the plug from the filter 10. The plug 30 may be made of a similar moulded plastic as the filter 10, or may be made of a rubberised material.

Various modifications may be made in details of design and construction without departing from the scope and ambit of the invention.

Claims (9)

1. A filter for use in a sink, comprising:- a filter body, means for engaging the filter body over a drain hole of the sink, and a plurality of holes formed through the filter body for allowing liquid to drain therethrough but trapping particulate matter, wherein the holes are so spatially arranged to provide at least two vertically spaced apart drain paths for the liquid, wherein when a first drain path becomes clogged with trapped particulate matter, at least a second drain path located above the first drain path continues to allow liquid to drain therethrough.

2. The filter of claim 1 wherein the filter body includes an elevated portion through which the holes providing at least the second drain path are formed.

3. The filter of claim 2 wherein the holes are vertically extending slots formed through one or more side walls of the elevated portion, wherein the first drain path is through a bottom region of each of the slots and the second drain path is through a region of each of the slots above the bottom region.

4. The filter of claim 2 or claim 3 wherein the elevated portion has a maximum height which is above a bottom surface of the sink surrounding the drain hole. The filter of any one of claims 2 to 4 wherein the filter body includes a depressed portion that has a maximum depth which is below a bottom surface of the sink surrounding the drain hole.

I_ I

6. The filter of claim 5 wherein the elevated portion is located centrally of the depressed portion.

7. The filter of claim 5 or claim 6 wherein the depressed portion has a plurality of horizontally extending slots formed therethrough.

8. The filter of any one of claims 2 to 7 wherein the elevated portion includes a plurality of holes formed through a top wall thereof.

9. A filter and plug assembly for use in a sink, comprising the filter of any one of claims 1 to 8 and a plug adapted to be coupled to the filter when the filter is fitted in a drain hole of the sink so as to prevent liquid draining therethrough. Dated this 16 th day of May 2003 Gong An Dang PETER MAXWELL ASSOCIATES Patent Attorneys for the Applicant