Note: Descriptions are shown in the official language in which they were submitted.
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STRAINERS AND PLUGS
FIELD OF THE INVENTION
The present invention refers to a disposable strainer designed for use in
sinks, bathtubs, drains and so on.
BACKGROUND OF THE INVENTION
It is nowadays customary to cover the drains of sinks with strainers that
are usually made of metal or plastic and are designed to prevent masses of
waste from entering the plumbing system. It is customary to manually collect
the waste on the strainer, remove the strainer from the drain hole, empty the
waste into the garbage can and return the strainer over the sink's drain hole
for
further use.
The need to collect the waste from the bottom of the sink by hands, pile
it up on the strainer, remove the strainer, empty the waste into the garbage
can,
and clean the strainer from pieces of scummy waste that often stick to it, is
unpleasant, to say the least, and constitutes a problem for the general
public.
The present invention offers an appropriate, efficient and inexpensive
solution
to this problem.
US 7,442,296 to Won describes a disposable drain strainer that is
removably received within a drain opening having an adjacent drain rim
substrate. The strainer has a strainer portion, a ring portion, and a seal
release
mechanism. Top and bottom surfaces of the ring portion are adapted to
sealingly engage the drain rim substrate. The seal release mechanism is
integral
with the ring portion, and facilitates release of the seal so that the
strainer can
be readily be removed from the sink and discarded. The strainer is described
to preferably have a thickness no greater than 0.091 cm (910 p.m). However, it
will occur to the skilled in the art that for various reasons, such be made
very
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much lower than that thickness, for example injection molding cannot make
strainers thinner than 400p.m.
One object is to improve the adhesion of strainers to sinks; another to
improve the printablilty of strainers; yet another is to provide strainers
that are
more efficient; another is to provide strainers easier to produce. Yet another
is
to reduce the waste of material by making the strainer thinner - than
attainable
under the limits of production by mold injection.
SUMMARY OF THE INVENTION
According to one aspect, an extra-thin and flexible strainer or plug,
having a thickness of between 150 and 350 p.m is provided.
According to another aspect, a sink/bath comprising: a surface; a drain,
and a strainer or plug, the strainer or plug configured to fit over the
sink's/
bath's drain and adhere to the sink/ bath surface adjacent to the drain, the
strainer characterized as having a rim extending to at least 10 mm onto the
sink/bath surface is provided.
According to yet another aspect, a strainer or plug comprising a
circumferential ring, a middle concave part and a circumferential side is
provided, the ring characterized as being at least 15 mm wide.
The strainer or plug may be configured for single use or for a small
number of uses.
The strainer or plug is preferably made of a material that self-adheres to
a wet sink surface.
Preferred embodiments further comprise at least one lifting tab.
Some embodiments further comprise materials that can be printed upon.
Some strainer embodiments further comprise tiny protrusions in the
perforated bottom of the strainer's middle part.
Some embodiments are configured to exude a fragrance.
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Some strainer embodiments are composed of one or two strainers that
are positioned one over the other and are joined in a way that enables them to
be rotated in relation to one another.
Some strainer embodiments have two tabs are opposite each other.
Some strainer embodiments with tabs have the tabs are marked to allow
easily identifying the tabs.
In some preferred embodiments the tabs are configured to allow
breaking the adherence of the strainer or plug to the sink/bath surface.
Some strainer embodiments comprise recyclable or recycled materials.
Some strainer embodiments comprise materials selected from a group
comprising PLA, PET, PP and PS, with the proviso that the materials exclude
materials that lose mechanical strength within hours of contact with liquid.
Some strainer embodiments further comprise a material that catalyzes or
facilitates decomposition or degradation of the strainer or plug.
Preferably, embodiments are produced by vacuum forming / thermo-
forming.
Preferably, the extra thin strainer embodiments comprise a
circumferential ring at least 10 mm wide.
Some embodiments are made of material that is sufficiently flexible to
allow picking the strainer or plug as a sack.
Preferably, the strainer rim is sufficiently wide to prevent refuse from
falling in a sink's drain when the strainer is removed from the sink.
Preferably, the rim is sufficiently wide to collect refuse not reaching a
sink's/bath drain when the strainer is placed over the drain.
In some embodiments all surfaces of the plug or strainer are printed.
According to another aspect, vacuum forming /Thermoforming a strainer
or plug is provided.
According to another aspect, a sink/bath is provided, the sink/bath
comprising: a surface; a drain, a metal cover and a strainer or plug, the
strainer
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or plug configured to fit over the sink's/bath's drain and adhere to the sink
surface adjacent to the drain, the strainer characterized as having a rim
extending to at least 15 mm beyond the metal cover.
Some embodiments further comprise OXO.
Some strainer embodiments have a ring at least 20mm wide.
BRIEF DESCRIPTION OF THE FIGURES
The drawings attached to the application are not intended to limit the
scope of the invention and the possible ways of its application. The drawings
are intended only to illustrate the invention and constitute only one of many
possible ways of its application.
Figure 1 depicts a perspective view of a strainer that is composed of a
circumferential ring with a lifting tab, and a concave middle part that is
composed of a circumferential vertical side and a bottom with perforations;
Figure 2 shows the strainer of Figure 1 in a view from above;
Figure 3 illustrates the strainer of Figure 1 in a side view, showing the
lifting
tab on the left;
Figure 4 shows the same strainer, viewing the lifting tab as facing into the
page;
Figure 5 depicts in perspective view a strainer with additional protrusions
designed to help trap waste and prevent it from going down the drain;
Figure 6 shows the strainer of Fig 5 in a cross-section side view;
Figure 7 depicts a side view of a double strainer made up of one perforated
strainer and a conforming plug;
Figure 8 illustrates separation of the perforated strainer and plug of the
double
strainer;
Figure 9 schematically shows a side view of a double strainer made of two
perforated strainers;
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Figure 10 shows a side view of the strainer depicted in Fig. 9, in which
liquid
passes via the strainer;
Figure 11 shows a top view of the bottoms of the two perforated strainers
depicted in Fig. 9, in which liquid may pass via the strainer;
5 Figure 12 shows a top view of the bottoms of the two perforated strainers
depicted in Fig. 9, in which liquid may not pass via the strainer;
Figure 13a shows a roll of plastic film for forming strainers;
Figure 13b shows the heating of a plastic film in a vacuum forming/
Thermoforming system;
Figure 13c shows the plastic film start to deform in the vacuum forming/
Thermoforming system;
Figure 13d shows the plastic film brought into contact with a vacuum mold in
the vacuum forming/thermoforming system;
Figure 13e shows the vacuum formed sheet in the shape of a strainer on the
mold;
Figure 13f shows the strainer separated from the mold.
DETAILED DESCRIPTION OF THE INVENTION
Strainers and plugs are provided. For simplicity, strainer embodiments
are described hereinbelow, except for some specific examples of plugs. The
description below of strainers thus is to be applied mutatis mudandis to
plugs,
unless a particular description of plugs is explicitly described following
regarding those strainer embodiments.
The strainers are designed to be used over the drain holes of sinks,
bathtubs, and so on. The strainer embodiments 1 in Figures 1 to 4 are intended
to be used once or a small number of times at the most and have the general
composition of a circumferential ring 2 and a middle part 3 with perforations
6.
The circumferential ring 2 constitutes the external rim of the strainer 2
and has the general shape of a flat, closed ring. The middle part 3 can be
flat
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(particularly for use over drain holes in showers that have a metal lattice in
the
floor), concave or convex, and it can have a circumferential vertical side 4
and
a bottom 5 with perforations 6 so as to form a general structure of a
cylindrical
or dome-like bowl. The circumferential side 4 can be vertical if the middle
part
has the general shape of a cylinder or it may be curved if the middle part has
the general shape of a dome. The middle part 3 can be either convex or
concave. The strainer 1 is made of one integral piece.
According to one aspect, the external diameter of the circumferential
ring 2 is such as to essentially prevent waste falling into the drain when the
strainer is picked up, as well as allow prolonged adhesion of the strainer to
the
sink surface when the trainer is placed on the sink drainage hole. . The
external
diameter of the strainer/plug is generally variable, for example about 135 mm
in sinks with drain holes of 85mm that have a metal cover of 105mm, although
it may be larger or smaller, provided the adhesive property of the strainer 1
is
retained: all other parameters being equal, the larger the circumferential
ring 2,
the stronger the adhesion of the strainer 1, as will be explained later on in
the
application. In terms of ring width, the ring is typically at least 15mm wide
so
as to extend and contact at least 10 mm onto the sink or bathtub's surface: in
many sinks there is a depression of a few mm surrounding the sink's drain, and
the ring has to span and extend beyond this depression well onto the surface,
and thus strainers, more particularly for sinks, preferably have a somewhat
wider width of at least 20mm, whereas plugs for baths without such
depressions may have a smaller diameter. The diameter of the middle part 3
corresponds, in general, to the dimensions of the drain holes the strainer 1
is
intended to be used over. The depth of the middle part 3 (if it is concave) or
its
height (if it is convex) can range from 40 mm deep to 10 mm high, although
other dimensions are also possible.
According to another aspect, the strainer 1 is very thin, preferably less
than 400 microns thick and down to about 150 m or less, dependent upon the
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strength of the material from which the strainer is made. The material has to
be
sufficiently thick to allow detaching the strainer from the sink surface and
picking up the strainer loaded with refuse, without tearing or collapsing. In
some embodiments, this novel minimal thickness enables the strainer 1 to be
highly flexible. The unique structure of the strainer 1 enables both very
efficient, fast and very inexpensive manufacture, being manufactured from a
much reduced amount of material compared to strainers made by injection
molding, conserving storage and shipping space. The environmental impact of
the product is thus much reduced both in manufacture and in disposal. In
addition, the fact that the strainer 1 is extra-thin and/or has a wide rim may
enhance its adhesion, as will be explained later on.
In some embodiments, the strainer 1 can self-adhere upon contact with
water. This property of the strainer 1 stems, among other things, from the
type
of materials used to manufacture it, its overall design, e.g. flexibility
(from
material and thickness) and surface area of the rim, and the unique property
of
water molecules that results in the creation of attraction and adhesion
forces.
The strainer 1 is made of a polymeric material, preferably of a type that is
not
mechanically compromised by short period wetting such as recycled and
recyclable HDPE, PLA, PS, PP or PET with or without additives, including
OXO, which is used to catalyze the biodegradation of the material. Paper is
generally unsuitable, as it will lose its mechanical strength within minutes
of
becoming wet. All of the above materials can be supplied in extra thin sheets
and extremely flexible and can be folded rapidly and efficiently. Most
importantly, all of the above materials can self-adhere, such that when the
strainer 1 [or more accurately, the circumferential ring 21 is placed on a
sink
surface and/or bathtub surface and/or basin surface with a drain hole and/or
on
the circumferential ring of the drain hole itself (hereinafter referred to as
the
"basin surface"), the strainer adheres efficiently to the basin surface thanks
to
the moisture captured between the underside of the circumferential ring 2 and
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the surface of the basin surface. The adhesion occurs, among other things,
thanks to the vacuum created between the underside of the circumferential ring
2 and the surface of the basin, and also due to the fact that water penetrates
between the two surfaces, causes attraction and adhesion forces between them.
In preferred embodiments wherein the rim is meant to adhere to the sink,
the circumferential ring 2 is relatively large and its external diameter
should
preferably be significantly greater than that of the drain hole, i.e. at least
lOmm
wider, so that its contact area with the basin surface is large enough to
create
effective adhesion. In such a way, the strainer 1 is positioned firmly over
the
drain hole and does not shift. This adhesion is caused not only due to the
weight and geometry of the strainer (in that the concave part fits into the
drain
hole) but also due to the properties and structure of the strainer and the
properties of the water. The wide rim of the strainer 1 also enables the user
to
accumulate a greater quantity of waste and dirt on it, and the fact that the
strainer 1 is extra thin and flexible also enhances the effectiveness of its
adhesion. The wide rim also helps prevent from refuse falling into the drain
when the strainer is lifted off the sink surface. It should be appreciated
that
commercially available strainers that are not as wide are precarious, as they
expose the sink to blockages due to inadvertent spillage of waste into the
drain
during their manipulation.
The strainer 1 can be round, elliptic, or have any other geometric shape.
As mentioned, the middle part 3 of the strainer 1 has perforations 6 and is
designed to be positioned over the drain hole. The strainer 1 enables water to
flow through the perforations 6 into the drain, whereas the waste is stopped
and
accumulates on the strainer 1. The strainer 1 can be equipped with one or more
lifting tab 8 to facilitate its removal in order to discard it into a garbage
can
along with the waste accumulated on it as well as to help lift the strainer
off the
sink surface. In preferred embodiments, there are at least two tabs,
preferably
opposite each other. Two tabs may allow to stably lift the strainer in the
shape
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of a sack, thus minimizing spillage and visibility of refuse on the strainer.
The
tabs themselves may be made of printable material, and be printed upon or
highlighted, either in part or over their entire surface, to help a user
locate the
tabs.
In some embodiments, the material the strainer 1 is made of can be of a
type that can be printed on, in which case the strainer 1 may serve as
advertising space, (for instance for detergents, or kitchen products) or have
some aesthetic print on it. In some embodiments, the material of the strainer
1
is made orcan contain or have a coating containing a fragrance.
In some embodiments a strainers such as l', shown in Figures 5 and 6
have tiny protrusions 7 on the bottom 5 of the middle part 3' so that the
waste is
caught on the protrusions and accumulates on them, creating an empty pocket
between the waste and the strainer base, and preventing the perforations 6
from
being clogged. In this way, water can flow freely through the perforations 6
into the drain hole even when waste has accumulated on the strainer l' and
thus
improves drainage. The protrusions also improve the trapping and capture of
the waste and prevent it from getting washed down the drain.
Other embodiments refer to double strainers 10, 10' shown in Figures 7
to 12 that are made up of two strainers of the kind described above or a
strainer
above a plug. In Figures 7 to 8 a strainer 12 is placed over a plug 14. In
Figures 9 to 12 a strainer 12 is placed over another strainer 12'. For
simplicity,
only the bottom part of the strainer 12' is shown. The two strainers 12, 12'
are
placed one on top of the other and their centers are joined together in such a
way that they can be rotated in relation to one another. When the perforations
6
on the two strainers 12, 12' are aligned, Figures 10 and 11, water can flow
freely from the basin into the drain hole. Alternatively, one of the two
strainers
1 can be rotated slightly so that the perforations 6 on the two strainers are
not
aligned and an impervious surface is formed, as in Figures 9 and 12. In this
position, the double strainer 10 serves as a kind of stopper or plug,
preventing
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water from flowing down the drain. The double strainer 10 can thus serve both
as a strainer and as a stopper for the relevant basin according to need. In
addition, the double strainer 10' is less likely to drip when it is removed
and
discarded along with the waste accumulated on it. The double strainer 10 can
be composed of two separate parts ¨ one strainer 1 with perforations 6 and a
second "strainer" 1 without perforations that serves as a stopper.
The double strainer minimizes dripping of liquids from the strainer
during the extraction of the strainer from the sink and transfer of the
detritus to
the rubbish bin.
Further embodiments refer to a component (not shown) that resembles
the aforementioned strainer but has no perforations and is used as a single-
use
stopper for the drain hole and/or as a kind of drip-tray when discarding the
waste from the drain hole into the garbage can. Optionally, the lifting tab in
these embodiments span the centre of the strainer, to allow a larger surface
area
to be available for contact between the rim and the sink surface and thus
maintain a complete seal and prevent seepage of water to the drain.
The strainer 1, may be used as follows: The user places the disposable
strainer over the drain hole. The presence of residual water causes the
strainer
to self-adhere to the sink and prevents it from moving from its position over
the
drain hole. The user can collect the waste on the strainer, and if necessary,
fold
5 it so that it envelopes the waste and discard it into the garbage can
along with
the waste that is in it. In this sense, the strainer is disposable. When the
strainer
is used over a bathtub drain it can save the user the unpleasant task of
collecting and removing hair that is caught in the drain's permanent lattice
or in
the drain hole itself. The strainer may also be used over floor drain holes
10 (usually located in the bathroom floor) when the floor is being washed
and the
wash water is drained through the said drain hole. Thus the strainer prevents
waste from entering into the drain system along with the water and also saves
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the user the unpleasant task of having to collect such waste from the wash
water.
Figure 13a shows an extra thin sheet of printable polymeric material,
typically thinner than about 350p.m.
In general, plastic utensils are manufactured by injection molding or
Vacuum forming/ Thermoforming (herein below abbreviated as VF). Utensils
of a size and shape complexity comparable to those of strainers/plugs,
manufactured by injection molding, are limited to a minimal thickness of about
400p.m. Wide rims and sunken centers render the strainers impossible to
produce to that thinness by injection molding.
There are a number of advantages to manufacture of multi-planar extra
thin perforated strainers and plugs by VF. The thinness much improves the
adhering strength of the strainers, allowing them to stay in place even inder
a
very strong stream of water. The increase adherence is due in part to the
increased flexibility of the strainer that allows the strainer to better
conform to
every minute feature of the sink's surface. The increased adherence as well as
the extra thinness also allows washing the detritus in a relatively strong
stream
of water onto the strainer, whereas thicker strainers have more limited
adhesion
and form a physical barrier due to their height above the sink surface.
Another advantage consequent to manufacture by VF is the ability now
open to print over the entire surface of the strainer by simpler, cheaper and
faster technologies, including the concave part, walls, contours, tabs etc on
a
sheet's surface, possibly with unique designs, advertisements and/or uniquely
designed strainers), whereas injection molding only allows printing on the rim
or the bottom of the strainer (to be precise ¨ only on flat surfaces) or very
slow
and complex printing by technologies suitable for printing on 3D objects. The
larger printable surface allows printing content that would be impossible to
create in injection-molded strainers.
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Moreover, the higher the proportion of recycled material in the material
to be molded, the harder it is to produce quality printing on any surface of
the
molded material. However, surprisingly this limitation does not apply to VF
formed strainers.
Referring to Figure 13b, an extra thin plastic sheet 2110 is typically
decorated or printed upon (not shown). before being placed in a VF system
2300. The VF system comprises a vacuum block (mold) 2330 having suction
holes 2340, heating element 2350, sheet holders 2360 and vacuum machine
2370.
Sometime after heating, the sheet 2110 becomes pliable, Figure 13c.
The sheet 2110 is then lowered to the vacuum block 2330, Figure 13d. A
vacuum is then applied via the suction holes 2340, upon which the sheet 2110
conforms to the shape of the vacuum block 2330, Figure 13e. After cooling,
the formed sheet 2110 is raised from the block 2330, Figure 13f, and removed
from the VF system. The formed sheet may now be perforated to form a
strainer, or may remain un-perforated to be a plug.
Some hydrophobic materials, for example polymers such as
polypropylene and polystyrene, might adversely affect the adhering strength of
the strainers to the sink surface since they repel water and thus do not
strongly
adhere to the water as hydrophilic materials do. Some materials might have a
low specific-gravity, lower than water's, that may interfere with adherence.
Nevertheless, the strainers and plug shave been found to have excellent
adherence even with these materials, thanks to either/or the wide rims, the
thinness and the flexibility of the material. . A flip side of the
hydrophobicity
is that the upper surface of the strainer repels water, which facilitates
removal
of the strainer without drips and may decrease the adhesion of the wet offal
to
the surfaces of the strainer.
Notably, most sinks have a metal cover over the drainage hole of the
sink. The strainer embodiments have a rim that extends beyond the cover to the
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ceramic or metal surface of the sink itself. The extension to the surface of
the
sink is particularly important in ceramic sinks, since it has been found that
the
strainers made of hydrophobic materials adhere better to wet ceramic surfaces
than to wet metal surfaces.
Preferably, the strainer rim extends in such drains to at least lOmm
beyond the cover.
The strainer 1, subject of the present invention, constitutes an efficient
and inexpensive solution to the aforementioned problems and offers one or
more of the many advantages, as follows: (a) Due to the strainer's wide rims
in
some embodiments, a larger amount of waste may be accumulated on it. (b)
Use of the disposable strainer avoids the need, the trouble, and the
unpleasantness of emptying the waste into the garbage can and rinsing the
strainerbefore reusing it, as in the case of the standard strainer. (c) Using
the
disposable strainer is convenient, efficient, and more hygienic. The wide rim
and its thinness allow efficient flow of refuse into the concave part and to
accumulate a large quantity thereon. All these qualities help to minimize and
ease any dealing with the rubbish. (d) The lifting tabs at or near the edges
of
the rim which allow minimal contact with the detritus, facilitate cancellation
of
adhesion and enable easily picking up the strainer. (e) The wide rim minimize
invasion of refuse not stacked on the strainer into the drainage system,
during
disposal of the rubbish (optionally together with the very thin strainer). (0
The
wide rim can be used for unique prominent advertisements, decoration etc. (g)
The thinness in some embodiments allows printing on the entire surfaces of the
strainer. Typically, only the top surface is printed. Such printing is not
present
or feasible in commercially available strainers. (h) When the invention is
implemented on bathtubs and floor drains holes (usually located in bathroom
floors), the strainer 1, subject of the invention, constitutes an efficient
way of
preventing waste from entering the plumbing system. (i) Most importantly, the
strainer 1 self-adheres to surfaces upon contact with water, having a wide rim
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and/or being very thin and very lightweight, and so adheres well to the
surface
around the drain hole.
1
