Hair Trap This invention relates to an improved strainer for a fluid outlet, such as the waste drain outlet of a receptacle used for washing, such as a sink, wash basin, shower tray or bath.
Such a drain outlet generally comprises an open conduit portion, usually but not necessarily of circular cross section, extending from the base of the receptacle, optionally provided with a plug to retain fluid within the receptacle.
It is undesirable for debris that collects in the receptacle to be discharged through the drain outlet as they can block the drain outlet and subsequent pipes, and / or cause unpleasant odours. Some drain outlets are provided with a coarse metal grille built in to the outlet, which serve mainly to prevent large objects falling through the outlets and still allow much debris to pass through.
A particular problem concerns strands of hair being trapped when a person washes their hair. Such strands frequently become twisted together and twisted round the coarse metal grille at the outlet from the receptacle. They have to be removed manually, which can be difficult, and which many people find distasteful.
In US-A-5,376,264 there is disclosed a strainer in the form of a filter disc of plastic mesh which is releasably attached to an annular support. The support in turn has means by which it is attached to the inside of the receptacle, over the drain outlet, such as double sided adhesive tape, glue, suction pads or magnets. Alternatively, the support may be provided with clips which extend into the drain outlet and engage against the inside of that. A problem with such an arrangement is that it prevents the use of a separate plug to close the drain outlet, and a specially designed and installed built in closure would have to be provided in the drain outlet itself. A further problem is that after washing the hair, strands of hair will be caught up in the mesh. Removing this hair will be at least as distasteful as removing it from a drain outlet.To discard the mesh without cleaning it will involve separating the parts of the strainer, which is troublesome and fiddly, and the mesh may not be intended for disposal after only one use.
There is therefore a need for a system which, amongst other things, will permit strands ofhair to be trapped and disposed of easily and efficiently.
Viewed from one aspect, the present invention provides a method of straining waste liquid flowing through a waste outlet of a receptacle, for example a receptacle used for washing, the outlet comprising a tubular portion extending below the receptacle and accessible from the receptacle through an opening, the method comprising the steps of placing through the opening and into the tubular portion, a disposable strainer comprising a wad formed from a plurality of layers of intersecting filaments of plastics material.
In a typical use, before washing the hair for example, the wad is placed by hand in the waste outlet. It may be a standard unmodified waste outlet and no special tools or fittings are needed. A plug may be inserted as usual, and may remain watertight, above the wad. When fluid flows through the opening, for example after the plug has been removed and the fluid leaves the receptacle or for example whilst rinsing the hair with no plug in place, strands of hair will be caught up on the wad. When washing is finished, the wad can simply be removed from the waste outlet - taking the hair with it and disposed of. The next time that the hair is to be washed, a replacement wad can be placed in the waste outlet.Alternatively a given wad may be left in place for a period of time during which washing takes place a number of times, and removed and disposed of only once it has collected a certain amount of debris. Users will find it quicker, easier and less distasteful to trap and dispose of strands of hair in this manner. Of course, the strainer can be used to trap other debris, for example when peeling vegetables or when there are fatty residues. It can be used in the context of washing people, animals, dishes, clothes, muddy footwear and so forth. For example, in the latter case the wad could trap mud, grit and strands of grass from football boots.
There are many shapes that the wad could be. For example, the wad could be in the form of a ball, although such a ball does not need to be spherical. Or, for example, the wad could be in the shape of hamburger or a thin disc. The wad does not need be circular in any plane, but might for example be a rectangular shape like a book. The wad need not be of a regular shape at all. The wad does not need to have a continuous outer surface.
In one preferred embodiment the wad comprises a number of projecting wings or pleats, for example in the form of separated portions of mesh, some or all of which may be portions folded over at their outer ends. In a particularly preferred embodiment, the wad is in the form of a miniaturised version of a body scourer such as the Caress Luxury Body Puff from Empress Garland Ltd, Campfield Road, Shoeburyness, Essex SS3 9FL, England (trading as EGL Homecare), which is to say a small version of the device disclosed in US 5,144,744 and WO 95/00116. This is made from an open plastic web, in particular a nylon mesh or net, more particularly a polypropylene or polyethylene mesh, gathered or "scrunched" up into a wad with several wings or pleats.
The strainer may simply be placed in the drain outlet and in some cases there is no need to provide means to retain it in place. It may, for example, rest on a coarse built-in metal grille provided in the waste outlet, where gravity, and/or pressure of fluid in the receptacle is sufficient to keep the strainer in place. Resilience of the strainer material may enable the strainer to be retained within the tubular portion by resilience in the radial direction of the strainer itself. The strainer may also be helped to stay in place by providing the strainer with wings, or projections from the main body of the strainer, which can extend down through the gaps in the coarse grill. Other means may be provided to retain the strainer in place, such as plastic clips, split rings, suction pads, magnets, adhesive tape, glue or other separate means to hold the strainer in place.However, in general these measures are unnecessary. If the strainer is retained by separate means, the force with which the strainer is retained should not be so high as to make insertion or deliberate removal, for example for rinsing or replacement purposes, difficult. It should be readily insertable and removable manually. The strainer may extend beyond the drain outlet into the receptacle. Insertion and removal of a plug need not displace the strainer in such an arrangement. The strainer may have axial as well as radial resilience. It will be engaged by and compressed by a plug when inserted, but will then expand axially to its normal length and indeed permeability when the plug is removed.
The wad may match the cross section of the tubular portion of the waste outlet. However a certain amount of clearance may be acceptable without detracting from the straining effect, for example, where the aim is particularly to catch relatively large debris or long strands of hair.
The material of the strainer can be arranged to provide an acceptable balance between filtering effectiveness and fluid flow. By using mesh material made from very thin filaments, and using overlapping and offset layers of such an open mesh, the size of the individual interstices can be such that the total liquid flow will be sufficient whilst the distribution of the plastics material defining the mesh can be such as to provide effective filtering. For example, a hair which passes through one of the interstices in one layer may meet a plastics portion in the layer below, and be retained, because the layers are offset.
Thus a strainer made from a wad of layers of a plastics mesh is easily located in the waste outlet, provides effective filtering and does not excessively impede fluid flow. Such a strainer can be removed from the waste outlet and either discarded or rinsed out and re-used. Preferably the material of the strainer is sufficiently inexpensive, and the cost of manufacture sufficiently low, that the strainer can be regarded as disposable, and in the preferred embodiment it is envisaged that the strainer will normally be disposed of once it has accumulated a certain amount of debris.
The preferred material for the strainer is the open mesh of plastics material. Preferably the filaments of the mesh are of very small diameter compared with the diameter of the holes, whilst remaining sufficiently strong to not break in normal use. This makes it possible to achieve an acceptable balance between the effectiveness of filtering and the speed of fluid flow. A very fine filter mesh, in other words a mesh with comparatively small holes, might remove most particles but will slow down the speed of fluid flow so that it takes an unacceptably long time to empty the receptacle.A strainer with very coarse perforations, such as the coarse metal grille usually fixed within a waste outlet, may not impede fluid flow excessively, but will only stop comparatively large pieces of matter such as vegetable peelings, whilst smaller particles or strands of hair may pass through and still cause problems in terms of the build up of solid matter, causing blockages and odours. Debris such as hair also gets tangled in the coarse strainer and it is distasteful, time consuming and difficult to remove it.
A number of separate sheets, or cylinders, of mesh could be superimposed and if desired joined together by mechanical means, such as sewing, or by bonding, for example using heat, a solvent or an adhesive. Alternatively a single sheet, or single cylinder, of mesh could be folded over or gathered up to create the overlapping layers, providing a resilient and permeable wad. The plastics material may be nylon, polyester or polyethylene or any other suitable polymer. The mesh may be formed by weaving, knitting, bonding or any other suitable process. The intersections between filaments defining the mesh may be bonded together by any suitable means, such as using heat to bond the plastics portions together. All or only some of the intersections may be bonded together. There may be bonding between at least some intersections within each layer and / or between adjacent layers.The shape of the strainer may be defined during a stamping or moulding operation use pressure and / or heat.
The mesh layers constituting the strainer may be made of different materials and/or be different in other ways, for example having different sizes or shapes of hole, or being of different thickness, stiffness, plasticity or resilience; and the layers may have different size, shape, colour, location, relationship to one another and so on, in order to provide the required shape, strength, resilience and straining properties of the strainer.
The holes may be any size or shape. The mesh preferably has interstices whose lateral dimension in any direction is no more than about 9 mm, and preferably is at least 0.5 mm and more preferably at least 1mm. For example the lateral dimension could be between about 2 and about 5 mm. The more layers there are the larger may be the holes in each layer. Holes larger than I Omm may be appropriate in some applications. Plastic filaments defining the mesh preferably have a diameter of no more than about 1 mm, and more preferably less than 0.7mm. The holes may be selected to strain a particular size and shape of debris particle; for example a coarse strainer may be selected for straining potato peelings and a fine strainer for straining hair. There may be more than one size and shape of hole in any one given embodiment of the present invention.
Whilst the strainer is preferably made from layers of a plastics mesh material in the above aspect of the invention, in alternative aspects the wad could be a porous foamed plastics or a porous non-woven web of fibrous plastics, in which any number of layers can be identified. The material could also be paper, wood fibre or any other suitable material.
Whilst preferably the wad is made from layers of an open plastics mesh, it could be formed by winding up one or more continuous filaments in various different directions so that intersections are formed. These could be left loose, or held or bound together in various ways, or contained or connected in various ways; and / or filaments could be joined at some or all intersections, for example using hot air welding or a similar technique.
The strainer may be made of nylon, Teflon , polypropylene, polyethylene or any other suitable polymer or plastic. It may also be of cotton, jute, metal, glass fibre, paper or wood products, or any other suitable material. Or any suitable combination of materials.
In some embodiments it is important that some or all of the material out of which the strainer is made is sufficiently resilient and flexible so as to stretch or compress as necessary, depending upon the design of the embodiment. In some embodiments it may be preferable for the material out of which the strainer is made, or some of it, to be not too flexible, and in some embodiments it may be important for some or all of the material to be rigid or comparatively rigid. For example, the doughnut, hamburger and scrunchy designs need material which is able to compress beneath the plug when the plug is inserted into the plug hole and then resile back to its original shape when the plug is removed.
The strainer as a whole may comprise one or more materials; each material, or layer or member of material, may possibly have different shape, and/or have different orientation, and/or be of different thickness, weight and flexibility, and/or be differently treated or impregnated or coated, and/or be differently connected to the other layers or materials, and/or be of different colour, appearance or design, and/or have different sizes and shapes of hole, or in some parts of the strainer, no holes at all.
The mesh material may be any material which permits the flow of liquid whilst preventing debris of a certain dimension to pass, given the anticipated rate of flow of liquid. For example, the mesh material may be any suitable polymer such as, for example, nylon, polyethylene or polypropylene, or alternatively any suitable plastic, rubber, natural or manmade fibre etc.. The mesh may alternatively be made from a resilient paper material or from other natural or man made fibres.
The straining element may comprise one or more layers of mesh or net material, each possibly with different shape, orientations and/or hole sizes and shapes, and/or being made of different materials and/or being differently treated or impregnated or coated, and/or being differently connected to the other layers, and/or being of different colour, appearance or design.
The material from which the strainer is made may be bio-degradable. It may be coated with or impregnated with a perfume, and/or a deodorant and/or an anti-bacterial and / or an anti-fungal agent for the purposes of hygiene and / or the masking or reduction of odours. For example, an anti-bacterial coating such as Microban may be used. It may be coated or impregnated with soap, cleanser, liquid cleanser, surfactants, antimicrobials, or bacteriostats, (in particular, halogenated - preferably chlorinated bacteriostats). For example, bacteriostats such as chlorhexidine; 3,4,4'trichlorocarbanilide; 2,4,41 -trichloro-2 -hydroxy diphenyl ether; 3,4',5tribromosalicylanilide; hexachlorophene; and 4, 4'-dichloro-3 - (trifluoromethyl) carbanilide may be used. Such a perfume, deodorant or agent may alternatively be in the form of particles trapped within the strainer.They may be applied to the strainer during the manufacturing process, and/or they may be applied to the strainer by the consumer, perhaps once the strainer is in place, or perhaps prior to putting the strainer in place.
Preferably the strainer is dimensioned to fit into a tubular portion whose internal diameter is between 20mm and 130mm, and for example between 32mm and 47mm, and for example between 39 and 47mm, and for example between 32mm and 38mm, and for example between 42 and 45mm, and most preferably, correctly dimensioned use in domestic waste outlets. However, a strainer of more than 130mm may be u' and this may be of interest in the context of a disposable strainer used in an aper other than a plug hole, such as an outlet from a distilling vat, for instance, or from a swimming pool, or sewage works.
The strainer may further comprise a hook, hoop, loop, tab, nipple, wing, brim, string or the like so as to be easily removable from the plug hole. This may be bonded to the strainer or, alternatively, may be formed as part of the mesh or other material out of which parts of the strainer are made. Including a loop, hook or the like facilitates the easy removal from the plug hole of the strainer which can then be discarded if fully or partially blocked, old or discoloured. The loop, hook or the like may form part of the resilient ring or supporting member. The tab may be made in an attractive or interesting shape to add to the appearance of the strainer.
Each of the embodiments of the present invention may further be made in an attractive pattern and/or shape and/or design; and of one or more colours. A disposable sink strainer may thereby enhance the appearance of the plug hole or other aperture, and thus of the sink, bath, shower cubicle, urinal and wherever a plug hole or similar aperture is located. A jar or other transparent container for a number of strainers, perhaps differently coloured, can be an attractive feature in a bathroom.
The disposable sink strainer described in this patent can have embodiments designed to be used in combination with other types of sink strainers, for example 'basket' type sink strainers, thereby improving the filtering performance of that other sink strainer, and obviating the need to clean that other sink strainer, and so on.
Some embodiments of the present invention allow two or more sink strainers to be used at once. This may be an advantage for a number of reasons, for example: the user could simply choose to use two or more in order to increase the amount of matter trapped; or, by placing two or more in the plug hole, the user could ensure that if one of strainers becomes clogged and needs to be removed, whilst there is still waste fluid in the sink or bath, then after that strainer is removed, there is still another in place to catch any remaining debris as the remaining waste fluid flows away - so at no point does unstrained fluid pass into the plug hole.
Although primarily described with reference to domestic applications such as sinks, baths and the like, the present invention can equally be employed in other applications such as, for example, urinals or, for example, industrial applications where a fluid strainer may be required which, for some reason, needs to be disposable, or in other domestic application, for example, specific embodiments of this invention could be placed on the grill at the top of the downpipe in the gutter round the roof of a house, to gather leaves etc. and after a period of time it could then be simply removed and thrown away along with the debris, making it quicker and easier to keep the down pipe unblocked.
Viewed from another aspect the invention provides a strainer for waste liquid flowing through a waste outlet of a receptacle used for washing, the outlet comprising a tubular portion extending below the receptacle and accessible from the receptacle through an opening, characterised in that the strainer is in the shape of a hamburger, comprising a plurality of flexible and resilient layers of intersecting plastics filaments, the strainer being dimensioned to fit releasably into a tubular portion whose internal diameter is between 20 and 80mm. Most preferably the strainer has a diameter corresponding to standard sink plug hole diameters.
Preferably the 'hamburger shape wad' comprises 2 or more layers of an open mesh. Preferably it has a plurality of wings, as described earlier. In use, a product supplied to a consumer may consist of a plurality of disposable 'hamburger shape wads', for example of different colours, in a suitable container such as ajar. The container may be transparent so that the coloured 'hamburger shape wads' are visible and it is an attractive item to keep in a bathroom. When the hair is to be washed, a 'hamburger shape wad' is taken from the container, placed snugly in the plug hole whilst the hair is washed and then thrown away.
In a modified embodiment of the invention, the strainer is for use with a waste outlet in which there is disposed a stem of an integral plug for the receptacle, which will be operated by a lever, knob or the like. The strainer is provided with a central aperture to receive the stem.
The preferred plastic mesh material is, on its own, an effective strainer even as a single sheet. It is thin, flexible and lightweight, has low friction so will not stick to the plug, allows comparatively high rates of fluid flow, and has an affinity for wet surface. When it is wet, fluid surface tension effects can help keep it in position. A single sheet, or more than one sheet, of such material can be placed over or in a waste outlet and will tend to remain in place. If a plug is inserted into the waste outlet, the plug will remain watertight, and can be removed without taking the mesh with it. A strainer made from such mesh could be in the form of a disc to fit in or over the waste outlet, or, for example, in the shape of a "top hat" with the brim around the opening into the waste outlet and the cylindrical portion projecting into the waste outlet.In either case, one or more layers of the mesh could be used. In embodiments of the strainer where a simple thin flat layer of mesh material performs the filtering, the filtering member may not need to be flexible, and indeed in some embodiments it can be easier to correctly locate the strainer in the plug hole if the strainer, or parts of it, are not too flexible. Other aspects of the invention relate to such alternative arrangements.
As will be appreciated, it is well known to filter debris and solids from liquids in industrial and domestic applications. In a domestic application such as, for example, a kitchen sink it is often undesirable for the debris that collects in the sink to be discharged through the plug hole. Debris can block pipes and plug holes, can become entangled in the coarse metal strainer of the plug hole, and can settle in pipework and plug holes, resulting in reduced flow capacity in pipes and through plug holes and/or unpleasant odours from pipework and plug holes. In industrial applications pipe blockages caused by debris not being filtered or strained from tanks or containers can, for example, result in damage to pumps and other ancillary plant and equipment.
Known straining and filtering systems provide various means to remove debris from liquids. For example, GB 705094 discloses a basic sink strainer which can be used with an ordinary plug hole of the type most commonly found in the UK i.e. where a rubber, plastic or metal stopper is inserted and removed manually. The strainer consists of a shaped metal or plastic plate which is placed over the plug hole in the sink and which has holes that allow the fluid to flow through whilst retaining the debris.
However, this type of strainer has a number of disadvantages. For example, it is often inconvenient to use because it has to be removed and stored when the plug is in use and in the plug hole and then, when the plug is removed from the plug hole and whilst the receptacle is still full of fluid, the user has to plunge his hands into the fluid and manage to replace the strainer over the plug hole in order to strain the liquid. The employment of such strainers results in there being a delay between removing the plug from the hole and putting the strainer in place which can allow debris to bypass the strainer and flow into the pipework. Furthermore, such strainers are in no ways fixed in place and so can easily be displaced from the plug hole, for example, by items moving around in the sink.In addition, this type of strainer is unattractive to look at, and with prolonged use can become positively unhygienic and unsightly as the surface of the strainer becomes stained. Inevitably, after the strainer is used, the user is required to perform the time consuming and distasteful task of cleaning the strainer, which generally involves using the fingers to scrape off the debris trapped by the strainer. A further problem exists in the cleaning process, which usually involves rinsing the strainer under the tap, which necessarily must take place whilst the strainer is not in place, so can result in the release of debris down the plug hole and into the pipework. The efficiency of these types of strainers is also sometimes limited because the holes formed in the plates are usually too large to trap most hair and smaller particles which are in the liquid.Such particles can also travel in fluid under the strainer and so be discharged without being filtered. In addition, the nature of the metal or plastic material out of which the strainer is made, is such that the material between the holes takes up a relatively large area of the aperture, so obstructs fluid flow. Failure to clean the strainer properly can also reduce the rate of flow of liquid through the strainer, making it less efficient, and can also result in it becoming unhygienic and lead to unpleasant odours as bacteria builds up on the strainer.
Another type of strainer is shown in US patent number 3,711,874 which discloses a 'basket' type sink strainer. Basket strainers suffer many of the same disadvantages as discussed above with reference to conventional strainers. In addition, however, basket strainers have to be an integral part of a specially designed and manufactured plug hole and/or waste pipe, which in turn may need to be accommodated within a specially designed and manufactured sink, bath, shower cubicle etc.. Such strainers cannot be used with an ordinary plug hole which is already in place and are relatively complicated and expensive to manufacture and install.The design of basket strainers also tends to impede the flow of fluid down the plug hole, with the result that if the tap is on the sink may undesirably fill up because the fluid is not flowing away quickly enough, and also with the result that when the sink is full it takes longer for it to empty. They also become unhygienic and unsightly with prolonged use, and have to be cleaned of debris which is a distasteful task.
There is therefore a need for a strainer suitable for use in, for example, a domestic sink or bath, which can efficiently remove debris from liquid flowing from the sink, bath or the like and which does not suffer from the problems associated with prior art strainers.
Viewed from a further aspect the present invention provides a strainer comprising a straining member adapted to cover substantially all of an aperture, wherein said straining member is a mesh or a wad of mesh.
The sink strainer may be located within the outlet pipe and may rest on the surface of the grille of the plug hole or may extend over the top of the plug hole and extend radially out from the edge of the plug hole. The strainer may have a circular straining member with vertical element extending therefrom corresponding to the side walls of a sink outlet and preferably also has a horizontal top element which extends from the top of the vertical element radially so as to cover the area of the receptacle around the plug hole opening.Of course, the present invention extends to a patent which does not have a flat straining member, for example, one that is the shape of a hamburger, or a doughnut, or a ball; the present invention extends to a patent which does not have a circular straining member, for example, one that is in the shape of a book, or the shape of a 'scrunchy' - i.e. effectively just a scrunched up ball of the mesh.
In general the strainer will rest on the grille within the plug hole, and fit snugly against the walls of the plughole, and thereby stay in place. In some designs the material will compress, under the pressure of the plug being inserted, into the gap between the fully inserted plug and the grille, only to expand again when the plug is removed. Thus this allows a conventional plug to be used as normal in conjunction with the strainer herein described.
Some plug holes have no grille, so the strainer may then be held in place through exerting pressure on the walls of the plug hole, and/or by the brim of an inverted top hat design, and/or through the use of clips, rubber type rings, adhesive, and/or in some other way. Some plug holes have a grille flush with the surface of the sink, so the strainer will not then be within the outlet pipe, and whilst the nature of the material is such that a thin layer of the mesh (particularly nylon or polypropylene or polyethylene net) will usually stay in place over the plug hole, the strainer might also be designed to have a shape and characteristics which further enables it to stay in place over plug holes of this type, for example through the use of wings or projections from the main body of the strainer, which go down through the holes in the coarse grill,and/or through the use of clips and/or in some other way.
All or part of the shape of the strainer may be formed during a stamping or moulding operation. For example, all or part of the strainer may be formed of a disc or other member of mesh material in which heat is used to soften the material etc.. Alternatively the vertical elements may be a rigid structure such as a moulded plastic member, or a flexible structure such as a ring or open ended cylinder made of polyethylene or the like; and the vertical elements may be connected to the other, horizontal, elements by suitable means such as bonding. In general, any elements of a particular embodiment of the strainer not performing the function of straining the fluid, may be of a material and design other than mesh.The materials from which the strainer may be made, and the way they may be combined, and possibility of applying coatings, and the dimensions of the strainer and of the holes within the mesh may be as described earlier.
Viewed from a still further aspect there is provided a sink strainer comprising a straining member adapted to cover substantially all of the outlet of a sink, wherein said straining member comprises a net or mesh which can be accommodated between the bottom of the plug and the coarse grill of the plug hole, and wherein said sink strainer has at least one flexible portion which can be accommodated between the external wall of a plug and the internal wall of a plug hole, and/or such that the plug can seal the plug hole.
To locate the strainer in the plug hole the strainer may also be provided with resilient rings or supporting members which may correspond to one or more dimensions of the plug hole so as to locate the strainer and maintain its position. The strainer can thereby be fixed in position and prevented from being dislodged or displaced accidentally. The rings or supports may be bonded to the material of the strainer or, alternatively, may be formed from the strainer material as part of the manufacturing process.
In many preferred embodiments, the present invention provides a sink strainer which may be disposable which can be used in a standard plug hole and left in place in the plug hole whilst the plug is inserted and removed, such that the plug suffers little or no loss of water tightness.
Embodiments of the present invention provide a strainer which can be used in standard plug holes and which is easy to install, manufacture and dispose of. In a preferred embodiment, the strainer is disposable and therefore removes the need for the user to clean the strainer and can also reduce the possibility of a build-up of bacteria, of smells and of the strainer becoming unhygienic.
There are many different possible embodiments of this invention. There are many different types of aperture, plug and plug hole in conjunction with which individual embodiments of this invention may be designed to be employed.
In one preferred embodiment the strainer is made in the shape of a 'top hat', where the cylindrical part of the 'hat' is placed into the plug hole, and the brim of the 'hat' remains in the receptacle lying around the edge of the plug hole. Top hat design sink strainers are known, but top hat design sink strainers in accordance with aspects of the present invention have several advantages over existing top hat designs, for instance, they are watertight when the plug is inserted and allow the plug to be used as normal, whilst the strainer remains in place. With known stainless steel and plastic versions this is not the case. A known paper cup design has the disadvantage that when you put the plug in it is very easy to catch the edge of the cup, thereby crushing it. The paper cup design also tends to tear, and to reduce the fluid flow.Also, when the plug is pushed firmly into the plughole and then removed, the paper cup tends to be pulled out with it. Some paper cup designs require specially designed fitments to be fitted to the sink in order for them to be used.
Top hat design sink strainers in accordance with aspects of the present invention remain in place when the plug is removed, through being made of very thin, low friction material. With the majority of known designs the plug does not even fit; and of the designs where the plug does fit, it does not remain watertight, and if you put the plug firmly into the plug hole, then when you pull the plug out it does tend to pull out the strainer with it. On the whole, known top hat designs of sink strainer are not designed to be used with the plug - rather they are used mainly in kitchen sinks for catching vegetable peelings and suchlike, without a plug in place. Top hat design sink strainers in accordance with aspects of the present invention have a higher proportion of hole to material, so allowing much greater rate of fluid flow.They are lighter and more compact, so easier and more convenient, to transport and store. They are cheaper to manufacture, so may be regarded as disposable. It is useful to have a strainer in a top hat shape because this can collect debris and can then be lifted out of the plughole along with the collected debris. If the cylindrical part of the top hat is made out of very thin, low friction material, such as nylon, or more particularly polyethylene, then the plug can be firmly inserted (and remain watertight) and removed, just as normal, without the strainer sticking to the plug and thereby being displaced when the plug is removed.Furthermore, when the top hat design has a cylinder and brim made of very thin low friction nylon type material (perhaps the same material as the straining element, perhaps polyethylene) and a straining element comprised of a layer of very thin mesh (perhaps polyethylene mesh), then it is possible to put more than one top hat shape strainer in the plug hole at once. This means that if the first strainer gets clogged it can be removed, leaving another strainer still in place, thereby preventing the passage down the plughole of unstrained fluids immediately after the first strainer is removed.
In one embodiment the entire top hat shape could be made of nylon mesh, whereas in another embodiment the top hat shape could be made of nylon without holes, apart from the straining element which would be made of mesh. In further other embodiments, the material out of which the top hat shape is made may be reinforced, and/or helped to stay in the desired shape, for example though the use of rubber-type rings or split pins, through rolling up or binding up the material in various places, through judicious sewing, gluing or bonding of the material, through nylon wire woven into the material at appropriate points, and so on. In yet another embodiment the disposable sink strainer could have a brim made of a relatively heavy material, which might help keep it in place.In yet another embodiment, the disposable sink strainer could be supplied with a separate brim, which could be reused, and which could be made of material which is comparatively heavy, which could be placed on the portion of the disposable sink strainer which projects into the receptacle, in order to help keep the strainer in position.
Inventive aspects disclosed include the method of putting a single layer of thin mesh in the plug hole resting on the coarse metal grill; such that when the plug is fully inserted the disc nestles in the gap between the coarse grill and the bottom of the plug. As a result the plug can be inserted and removed as it would without the sink strainer present; and due to the narrowness of the filaments of the mesh there is minimal reduction in the rate of fluid flow; and more than one can be used at once (meaning that if the top one gets clogged it can be removed without allowing any fluid to pass into the drain unstrained) - all of which are advantages over other sink strainers.When just a single thin flat layer of mesh is used as a sink strainer, the mesh need not be very flexible, indeed a certain degree of inflexibility may help keep it in position covering the whole of the aperture of the plug hole. The strainer can be fitted with string, loop, hook, tab, hoop, nipple etc. to facilitate removal.
Another inventive aspect concerns the use of a very thin mesh of e.g. nylon, so that the sink strainer may be comprised of more than one layer, so that particles passing through one layer can be caught by the next layer, giving improved filtering performance; whilst still being sufficiently thin to fit in the gap between the coarse grill and the bottom of the plug.
Using flexible resilient material relates to another inventive aspect. It means that the volume of the mesh wad sink strainer - and thus the spacing between the layers of the wad - when not under a compressive force, is greater than when it is compressed into the space between the plug and the coarse grill. This greater spacing between the layers of the strainer whilst it is straining, facilitates a greater rate of fluid flow, without compromising straining efficiency.
Yet another inventive aspect concerns the use of a higher surface area. Having a 3D (rather than planar) surface of the strainer means that the strainer has a higher surface area. As a result if, for example, one hole gets blocked by a piece of debris, there would remain many more holes unblocked than there would be were the strainer one with a planar surface. One embodiment with a 3D shape comprises a dome shape.
Yet another inventive aspect concerns making it the case that when the surface of the sink strainer is 3D, the shape of the 3D surface is such that there are sharp angles and ridges and valleys. This is because debris such as hairs tend to drape over the acute angles and ridges of a strainer (such as the 'wings' or 'pleats' described earlier), leaving the holes in the 'slopes' and 'valleys' unblocked. And if the 'valleys' get blocked by small particles the 'slopes' of the surface of the strainer may still remain unblocked. Thus this type of strainer tends to allow higher rates of fluid flow in practice, once the strainer has started collecting debris. One embodiment with such sharp angles, ridges and valleys, is the 'scrunchy' or 'irregular ball' design, discussed earlier.
The use of low friction material concerns a still further inventive aspect.
Various features of various embodiments can be combined. For example, a top hat design could combine with a wad strainer, or with half a scrunchy.
Viewed from another aspect, the invention provides a method of straining debris from liquid passing through a waste conduit from the bottom of a receptacle used for washing (such as a sink, basin, bath or shower tray), in which within the waste conduit and below the receptacle there is provided a permanent relatively coarse filter, the invention comprising the steps of positioning within the waste conduit a disposable, relatively fine filter which rests on the relatively coarse filter.
In the various embodiments there is provided a disposable sink strainer that may be, though need not necessarily be, made from inexpensive materials, materials of which there is no shortage, and so on. A sink strainer that may be, though need not necessarily be, cheap, simple and quick to manufacture, and light, compact and easy to distribute. There may be provided a disposable sink strainer that the user may conveniently throw away after use and, which, if manufactured from biodegradable materials, will not harm the environment or generate waste which does not break down.There may be provided a disposable sink strainer that through being easily put in place, removed and disposed of (through being easily placed in the plug hole, and plucked out of the plug hole, using one's fingers, and which may not need the use of special tools or fittings - although special tools and fittings may be employed in some embodiments) and not needing any special tools or fittings and through being economical to manufacture and distribute) may save time, money, effort, and distasteful labour with regard to the cleaning, and keeping clear of obstruction and of unsightly material, plug holes. Embodiments of the invention provide a disposable sink strainer that, when removed from the plug hole, facilitates the taking with it of the debris which it has prevented from flowing down the plug hole. Thus the disposable sink strainer and the debris may be disposed of together.
This disposable sink strainer, through being designed with a straining member being made of mesh, ordinarily comparatively little reduces the passage of fluid through the plug hole or other aperture. Although embodiments of the invention are generally described as disposable sink strainers, they can of course be used with plug holes not only in sinks but in baths, shower cubicles, floors, swimming pools, and so on. Indeed, specific embodiments of this invention may be designed to be used with many types of pipes, drains, channels, funnels, conduits and other apertures through which fluids flow, and may be designed so that whilst in place, they may (though need not) allow the use of a wide range of devices (such as plugs) for reducing or stopping completely the flow of fluid through the aperture or conduit.
Preferred embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings wherein :
FIGURE 1 shows a top plan view of the disposable sink strainer made out of thin mesh or net, in the shape of a disc. The strainer is shown in place in the plug hole, the flange of which can be seen surrounding it. FIGURE 2 shows a side elevation view of the disposable sink strainer shown in Figure 1. FIGURE 3 shows an upper side perspective view of the disposable sink strainer shown in Figure 1. FIGURE 4 shows a top plan view of the disposable sink strainer made out of thin mesh or net, in the shape of an inverted top hat with a wide flat 'brim'. The strainer is shown in place in the plug hole, the flange of which can be seen surrounding it. FIGURE 5 shows a side elevation view of the disposable sink strainer shown in figure 4. FIGURE 6 shows an upper side perspective view of the disposable sink strainer as shown in figure 4.FIGURE 7 shows a top plan view of the disposable sink strainer made out of thin mesh or net in the shape of an inverted top hat with a wide flat brim, with three rubber-type rings, to help keep the disposable sink strainer in shape and in place. The strainer is shown in place in the plug hole, the flange of which can be seen surrounding it. FIGURE 8 shows a side elevation view of the disposable sink strainer shown in figure 7. FIGURE 9 shows an upper side perspective view sink strainer shown in figure 7. FIGURE 10 shows a top plan view of the disposable sink strainer made out of thin mesh or net in the shape of a ring doughnut with a relatively small hole in the middle. The strainer is shown in place in the plug hole, the flange of which can be seen surrounding it. FIGURE 11 shows a side elevation view of the disposable sink strainer shown in figure 10.FIGURE 12 shows an upper side perspective view of the disposable sink strainer shown in figure 10. FIGURE 13 shows a disposable sink strainer having a domed shape. FIGURE 14 shows a disposable sink strainer having a domed shape, with twin layers. FIGURE 15 is a perspective view of a nylon mesh strainer in accordance with the invention, with a ball or "scrunchy" shape. FIGURE 16 is a cross section through part of a basin and waste outlet, showing the strainer of figure 15 in position; and FIGURE 17 is a cross section through part of a basin and waste outlet with an integral plug, showing a modified strainer of figure 15 in position.FIGURE 18 shows a top plan view of a disc of mesh, through the holes on the rim of which thread is threaded, this being one possible first stage of one method of making certain embodiments of the mesh sink strainer in accordance with the invention, such as the ball or hamburger shape sink strainer. FIGURE 19 shows a top plan view of a disc of mesh, out of the rim of which triangular 'teeth' have been cut, and through the holes on the rim of which thread is threaded, this being an alternative first stage in the aforementioned method. FIGURE 20 shows a side elevation view of the ball shape that is formed when the thread that has been threaded through the holes on the rim of the disc in Figures 18 or 19 is pulled tight. FIGURE 21 shows a side elevation view of the ball of mesh after it has been flattened to form a 'hamburger shape' sink strainer.FIGURE 22 shows a upper side perspective view of a cylinder of mesh, through the holes on the rim of each end of which thread is threaded, this being the first stage in another, similar, method of making certain embodiments of the mesh sink strainer in accordance with the invention, such as the ball or hamburger shape sink strainer. FIGURE 23 shows a upper side perspective view of a cylinder of mesh, out of the rim at each end of which triangular 'teeth' have been cut, through the holes on the rim of each end of which thread is threaded, this being an alternative first stage in the aforementioned method. FIGURE 24 shows a side elevation view of the ball shape mesh sink strainer that is formed when the thread that has been threaded through the holes on the rim of the cylinder in Figures 22 or 23 is pulled tight.FIGURE 25 shows two discs of mesh, which may be of similar or different diameter, where the perimeter of one is sewn onto the perimeter of another, from which, depending upon the size of the discs and the way they are stictched, may be made a variety of embodiments of the mesh sink strainer in accordance with the invention, such as the ball or hamburger shape sink strainer, a 2 layer disc shape sink strainer, or domed sink strainer. FIGURE 26 shows a side elevation of a hamburger shape sink strainer to the top of which some additional material has been attached. FIGURE 27 shows a side elevation of a hamburger shape sink strainer into the top of which some material of an attractive shape and colour has been incorporated.FIGURE 28 shows a top plan view of the hamburger shape sink strainer with a decorative flower attached FIGURE 29 shows a top plan view of the hamburger shape sink strainer with a logo or symbol attached.
The first two examples of preferred embodiments of this invention are illustrated in Figures 1 to 3 and Figures 4 to 6 respectively. These embodiments are designed for use with the type of plug and plug hole which is more common than any other in the UK, namely, where the plug is a stopper, usually made of rubber, plastic, manually inserted directly into the plug hole.
Figures 1 to 3 show an embodiment made from a thin nylon mesh or net (alternatively other materials may be used, for example plastic, acrylic, polyethylene, polypropylene, and the like, rubber, cotton, jute, metal, manmade fibres, and so on), in the shape of a simple disc 1 of the same diameter as the plug hole 2 which is part of a waste outlet having also an upper flange 3 and a lower coarse grille 4. The holes in the mesh made be of any shape, but are likely to be roughly square, circular, hexagonal or diamond shape having a largest dimension of2-5mm diameter, with the filaments of the mesh or net material having a thickness of less than 1mm. The disc then nestles in the plug hole on the coarse metal grille, in the small cavity below where the plug rests when inserted in the plug hole.In this embodiment the material does not need to be flexible, indeed a degree of inflexibility may be helpful when placing the strainer in the plughole and for maintaining its correct location therein.
Another preferred embodiment is shown in Figure 4 to 6. In this embodiment the strainer is in the shape of an inverted top hat 5 with a wide flat brim 6. The brim part 6 of the shape lies around the edge of the plug hole, extending over the flange 3, and the 'hat' part of the shape is about the same diameter as the plug hole, and nestles in the plug hole. The wide flat brim facilitates the insertion and removal of the disposable sink strainer, and helps keep it in place. It also, unlike a cup shape strainer, is not in danger of being displaced or crushed when the plug is inserted in the usual casual way.It is usually better for this embodiment of the strainer to be made of flexible material, and whilst the material needs to be thin, it is only the straining element that must have holes and so which needs to be made of mesh or net, or of a wad of mesh or net or of a bundle of filaments or suchlike. The rest of the strainer could, for example, be made of continuous nylon sheet.
Another embodiment described with reference to figures 7, 8 and 9 is of similar shape to the one just described, but involves the addition of one, two or three, rubber-type rings to help keep the device ir. the correct shape and in the correct position in relation to the plug and plug hole. In practice the effect of the rubber-type ring may be produced by simply rolling up the thin material from which the strainer is made, such as springy nylon mess, at the places where it is desired that there be the rubber type ring. In other embodiments there might also be struts, coils, split pins and other means used to help keep the device in the correct shape and position in relation to the plug and plug hole.
The strainer in the shape of an inverted top hat 7 with a wide flat brim 8, surrounded by the plug hole 2, and upper flange 3, with three rubber-type rings used to help keep the thin mesh or net disposable sink strainer in place and in shape: rubber-type ring 9 is placed inside the plug hole, at its base, and may help keep the sink strainer in the desired shape and may exert pressure against the wall of the plug hole in order to help keep the disposable thin mesh or net sink strainer in place; rubber-type ring 10 is placed around the mouth of the plug hole to help keep the mesh or net in the desired 'inverted top hat' shape, and perhaps also to help keep the strainer in place; rubber-type ring 11 is placed around the very edge of the brim of the strainer to help keep the strainer in shape and in place.
Yet another embodiment of the invention is shown in Figures 10 - 12. In this embodiment the disposable sink strainer can be adapted for use with a plug 12 of the type that is operated through the moving of a lever above the fluid level of the bath or sink; where the plug may have on its underside a narrow (several millimetres wide) stem 13 several centimetres long projecting down into the pipe, pressure on which from the lever moves the plug upwards allowing the fluid into the plug hole. In this embodiment the thin mesh or net can be formed into a ring or 'doughnut' shape 14 with a relatively small hole 15 (e.g. in the range 3 to 9 mm; preferably 5mm) in the centre through which the plug opening stem can travel.
Note that it would be possible to make the material surrounding the hole elastic so that when a stem is not inserted, the hole is closed up by the elastic material, but when a stem is inserted the elastic material expands to allow the passage of the stem. Note also that it would also be possible to construct a sink strainer such that the material in the centre of the sink strainer could be easily perforated and/or penetrated by a stem, without unduly affecting the surrounding material and the overall functioning of the strainer. The mesh material from which the straining element is anyway expected to be made generally has this property. Note also that any of the aforementioned measures, to allow the passage of a plug stem, could be embodied in any of the embodiments of the sink strainer.
It would of course be possible to make the disposable sink strainer in the shape shown in Figures 10 - 12 but without the hole in the middle, in which case it would take the 'hamburger' shape referred to earlier.
Figure 13 shows a sink strainer in the form of a dome 16 of the mesh referred to previously, positioned in the plug hole 2 and in this case projecting from its upper end. Figure 14 shows a dome shaped sink strainer in the form of two superimposed layers 17 and 18, whose rims are connected to each other, positioned in the plug hole 2. Three or more superimposed layers could also be used.
With reference to Figure 15, the strainer 19 is in the form of a wad comprising several layers of an open plastics mesh 20 which has been gathered up at 21 to form a number of wings 22 so that it resembles the body-scourer described earlier. The wad is thus in the form of an irregular ball, which can be used in any orientation. The strainer is inexpensive and intended to be disposed of and replaced after each use, or after having been left in place for a period of time during which the bath, basin, or whatever, has been used a number of times.
As shown in Figure 16, the strainer 19 is positioned within the plug hole 23 of a waste outlet 24 for a basin 25. The strainer rests on a conventional coarse permanent grille 26 within the waste outlet, such as an apertured metal disc, a coarse mesh or some cross members, which will prevent loss of the strainer 19 down the waste outlet. The strainer 19 matches the internal diameter of the plug hole 23. The strainer may originally have a maximum diameter somewhat greater than that of the internal diameter of the plug hole, and its inherent resilience and flexibility will permit it to be placed by hand in the waste outlet with little effort. To remove the strainer 19, a person's fingers can be used to pull it out of the waste outlet.
In Figure 17 there is shown a modified strainer 27, which is identical in construction to strainer 19, with the exception that there is a central axial aperture 28 so that the strainer can be used in a waste outlet 29 in which there is a stem 30 of a built-in plug 31. In use, the plug with its stem will be removed, the strainer placed on the stem, and then the plug and stem replaced. If the strainer cannot be slid over the stem due to a component at the bottom end of the stem, there may be a split in the strainer from the aperture 28 to its periphery, so that it can be placed axially over the stem. As in other embodiments, there is a coarse grille 32 in the waste outlet.
Figures 18, 19, 20 & 21 show a method of making certain embodiments of the sink strainer, such as the ball and the hamburger shape. Figure 18 shows a disc of mesh 33. The disc will need to be an appropriate size for the strainer design and aperture for which the strainer is intended. In general, for a simple hamburger shape to be described, the diameter of the disc will need to be approximately twice the diameter of the aperture for which it is intended. Take thread 36, and pass it through the holes, 35, in the mesh on the rim of the disc of mesh. This may be more easily accomplished through first attaching the thread to a needle.
Before passing the thread through the aforementioned holes on the rim, it may be anchored to the material at a point on the rim, 34, usually through a simple knot, though other methods such as glue or heat bonding are possible. Then when the thread is pulled tight, the material on the rim bunches up, 39, so that the mesh forms a roughly spherical shape, 61, as shown in Figure 20. Then the other end of the thread is anchored, so that it does not unravel, so that the spherical shape is maintained. It may be anchored through knotting it to the mesh, or in some other way.
Rather than initially knotting the thread to the mesh, it may have a loop at the end, or may be composed of one piece of thread doubled up, so that after the thread is passed through the aforementioned holes, 35, all round the rim of the disc, it returns to the starting point on the rim, where it may be passed through the loop or between the two strands, so that when it is pulled, it gathers up the material on the rim to form a bunch at 39 and so cause the mesh to form a roughly spherical shape, 61, as before. The thread is then anchored, so that it does not unravel. It may be anchored through knotting it, or in some other way.
If a ball shape sink strainer is required, then the process is now complete. However if a 'hamburger' shape strainer is required, then once a roughly spherical shape, 61, is formed, pressure, 40, is then applied to partially flatten the sphere, to create the hamburger shape, 43, referred to earlier, and shown in Figure 21. Note that if the material is quite springy then the top surface may need to be attached to the bottom surface to prevent the material springing back to the spherical shape. For example, the centre of the top surface may be sewn to the centre of the bottom surface. Note that the surfaces need not be touching, and that they may remain several millimetres apart, even after the sewing which is only needed to prevent the material resuming the spherical shape.However these steps may not be necessary if the material is only a little springy, or not at all springy, or naturally stays in the hamburger shape when it is pressed firmly into that shape, or if the material can be kept in the hamburger shape some other way, for instance through heat treatment.
Note also it would be possible to increase the number of layers in the strainer in a number of ways, for instance by taking one ball or hamburger or suchlike shape and making another round it, so that one would enclose the other, thus creating a strainer with twice as many layers. This process can then be repeated to create more layers. Or alternatively, the number of layers could be increased by taking two or more circles of mesh to start with, and sewing them.Note that sewing, stretching, compression, along with heat treatment, glue, application of further materials and so on could be used to change the shape of the strainer further, for instance to make a more attractive shape, or a shape that is more effective at filtering or that fits the appperture more snuggly.
Figure 19 shows a disc of mesh 37, out of which triangular 'teeth' have been cut, 38, in order to prevent excessive bunching at point 39. The triangles are roughly evenly spaced, and the appropriate size for them will depend upon the materials, the design, and the size of the circle and the aperture it is for. For example, for a strainer intended for use in domestic sink plug hole of diameter approximately 45mm, the circle will need to have a diameter of about 90mm and the triangle might have a base of. 2-8mm, more preferably 4-6mm and two sides of even length, of length 3-15mm, more preferably, 46mm.The method of making the hamburger shaped strainer from the disc of mesh 37 out of which triangular teeth have been cut, is the same as the method which starts with the disc of mesh 33; though it should be noted that it is best that when the thread is passed through the holes on the rim of the mesh 37, the spaces where the 'teeth' have been cut out are just passed over. In other words, thread is passed through all and only those holes that would have had the thread passed through them were there no teeth cut out of the disc. Figures 22, 23 & 24 show a method of making a mesh sink strainer that is similar to that shown in figures 18, 19, 20 & 21, but starting with a cylinder of mesh. In this case it is helpful if the material is somewhat springy.Figure 22 shows a cylinder of mesh, 42, and Figure 23 shows a cylinder of mesh 46 out of both ends of which have been cut triangular teeth 47 as described above. When using cylinder 42 or 46, thread 45 is taken, and passed through the holes in the mesh on the rims of both circular ends of the mesh cylinder, 44, as before, and may be anchored, 43, as before. Then, as before, the thread is pulled tight into a bunch as points, 39, forming a roughly spherical shape, whereupon the thread is secured. If a ball shape strainer is desired, the process is complete, but if a hamburger shape then, as before, pressure has to be applied to partially flatten the ball into a hamburger shape, and the strainer then fixed in the hamburger shape. Figure 25 shows two discs of mesh. The rim of one disc is stitched to the rim of the other.A variety of designs of strainer can be made in this way, by varying the relative sizes of the circles, and the way they are stitched together, and by treating them in certain ways once stitched - for example using stretching, compression, heat treatment glue, sewing, other materials and so on. For instance a simple hamburger or ball shape could be made by appropriate bunching on the rims, or by simply stitching the rims of two flat similar size circles on top of one another then pulling them into a ball shape and setting it through heat treatment. Alternatively one larger circle could have its rim stitched to a smaller circle, in such a way that the smaller base circle remains flat and the larger circle forms a dome. In such cases the smaller base circle would need to be the size and shape of the aperture.The larger circle could also be pleated on to the smaller circle so that the dome does not have simply a smooth circle but rather has some ridges. Alternatively the larger circle could be pleated, bunched or sewn or pulled or pushed into shape and then set in position, using sewing, heat treatment, glue or suchlike, in such a way as to make the large circle form some desired shape, such as the shape of a flower, or an irregular shape. And it is possible to treat both the upper and the lower circles in this way and to have them of similar or different size when doing so, and possible to carry out such procedures on one or more discs.Indeed the initial piece of mesh need not be a disc shape, and could be bunched up, and then kept in place by heat treatment or glue or sewing or in some other way, in order to make an irregular shape with ridges and valleys, or a flower shape, or some other required shape. Figure 26 shows a side elevation of a strainer to the top of which some material has been attached through sewing the material and the strainer together at one central point. However other methods of attachment are possible, for example through sewing the attached material to the strainer at a number of points, or sewing the attached material around its periphery, to the strainer. It may be attached other than through sewing, for example using glue or heat treatment. The material may alternatively be incorporated in the initial construction of the strainer.The strainer may have material attached to its top, to improve its straining properties, and/or to facilitate removal, and/or for decoration and/or for commercial purposes, such as in order to display a logo, emblem, symbol, letters, or for some other reason. How the strainer might appear from above with such material attached is show in Figures 28 & 29. Of course material can be likewise attached to other embodiments of the strainer. Figure 27 shows a strainer that has material incorporated into its top layer, whether to improve its straining properties, and/or to facilitate removal, and/or for decoration and/or for commercial purposes, such as in order to display a logo, emblem, symbol, letters.. How the strainer might appear from above with such material incorporated is show in Figures 28 & 29. Of course material can be likewise incorporated into other embodiments of the strainer.
The material referred to in Figures 26, 27, 28 & 29 should be chosen, and its size, shape, orientation and so on should be chosen, such that it does not reduce flow of fluid to unacceptable levels. This may be achieved either by choosing a material which allows the fluid to flow through easily, such as mesh, or by choosing a fluid permeable material, such as cotton or voil, and not covering too much of the area of the aperture with it, or by choosing a material which lets through little or no fluid, but covers a smaller area of the aperture, for example, attaching two small thin plastic letters.
Figure 28 shows a top plan view of the strainer, which could be, for example in a hamburger shape, ball shape, dome shape or disc shape, displaying a decorative 2d flower shape made of mesh. Figure 29 shows a top plan view of the strainer, which could be, for example in hamburger shape, ball shape, dome or disc shape, with a logo or symbol attached, in this case, the letters 'DD'. Note that these letters take up a relatively small part of the area of the aperture, so it would be possible for them to be made out of a non fluid permeable material such as rubber. Note also, they might still help catch hairs which would drape over them, and help catch other material also.
Note that the material attached or incorporated might be 3 dimensional, for example a 3 dimensional flower made of mesh, or a small rubber 3 dimensional racing car shape. In this case the 3d shape may also function as a tab which would aid the consumer in manually plucking the strainer from the plug hole.