U.S. patent application number 12/747707 was filed with the patent office on 2011-01-27 for water purification device.
This patent application is currently assigned to CREAHOLIC S.A.. Invention is credited to Marcel Aeschlimann, Andre Klopfenstein, Elmar Mock, Christoph Rusch.
Application Number | 20110017668 12/747707 |
Document ID | / |
Family ID | 39333095 |
Filed Date | 2011-01-27 |
United States Patent
Application |
20110017668 |
Kind Code |
A1 |
Mock; Elmar ; et
al. |
January 27, 2011 |
WATER PURIFICATION DEVICE
Abstract
A water purification device includes an expandable water
collecting device having a variable volume, wherein at least part
of the surface of the water collecting device includes a filter
area, the filter area being permeable to water and allowing water
to enter the water collecting device when the filter area is
submerged in water. The device further includes a mechanically
driven expansion means for exerting a force for increasing the
volume of the water collecting device and thereby drawing water
through the filter area into the water collecting device. In use,
the water collecting device is submerged and the expansion means is
released, drawing water into the water collecting device through
the filter membrane.
Inventors: |
Mock; Elmar; (Colombier,
CH) ; Aeschlimann; Marcel; (Ligerz, CH) ;
Rusch; Christoph; (Biel, CH) ; Klopfenstein;
Andre; (La Neuveville, CH) |
Correspondence
Address: |
RANKIN, HILL & CLARK LLP
38210 GLENN AVENUE
WILLOUGHBY
OH
44094-7808
US
|
Assignee: |
CREAHOLIC S.A.
Biel
CH
|
Family ID: |
39333095 |
Appl. No.: |
12/747707 |
Filed: |
December 4, 2008 |
PCT Filed: |
December 4, 2008 |
PCT NO: |
PCT/CH08/00515 |
371 Date: |
September 22, 2010 |
Current U.S.
Class: |
210/650 ;
210/232; 210/455 |
Current CPC
Class: |
C02F 1/44 20130101; B01D
29/117 20130101; B01D 2313/18 20130101; B01D 63/00 20130101; B01D
61/18 20130101; C02F 1/002 20130101; B01D 2313/24 20130101 |
Class at
Publication: |
210/650 ;
210/455; 210/232 |
International
Class: |
C02F 1/44 20060101
C02F001/44 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 13, 2007 |
EP |
07405353.9 |
Claims
1. A water purification device, comprising: a water collecting
device having a surface defining a variable volume, wherein at
least part of the surface of the water collecting device comprises
a filter area, the filter area being permeable to water and
allowing water to enter the water collecting device when the filter
area is submerged in water, wherein the device further comprises a
mechanically driven expansion means for exerting a force for
increasing the volume of the water collecting device and thereby
drawing water through the filter area into the water collecting
device.
2. The device of claim 1, further comprising an outlet for removing
clean water accumulated in the water collecting device.
3. The device of claim 1, wherein the volume of the water
collecting device is defined by a flexible sheet material.
4. The device of claim 3, wherein the water collecting device
comprises at least two sections of a filter membrane material that
are joined in a watertight manner along edges of the sections,
forming in the expanded state of the water collecting device, a
substantially pillow-shaped bag.
5. The device of claim 1, wherein at least a quarter of the surface
of the water collecting device is made of a material serving as the
filter.
6. The device of claim 1, wherein, when the water collecting device
is in a first configuration, comprising a reduced volume, the
expansion means comprises stored energy, and release of said stored
energy causes the volume of the water collecting device to
increase.
7. The device of claim 6, wherein the first configuration
corresponds to an essentially flat configuration of the expansion
means, and the increase of volume of the water collecting device
corresponds to the expansion means assuming a three-dimensional
configuration.
8. The device of claim 1, wherein the expansion means is arranged
inside the water collecting device and, when released, causes the
water collecting device to expand, increasing the volume of the
water collecting device.
9. The device of claim 1, wherein the expansion means comprises at
least one resilient element which releases stored energy by
changing its shape, in particular by at least one of bending or
unbending or expanding or contracting.
10. The device of claim 1, wherein the expansion means comprises
one or more struts that form a frame supporting the water
collecting device, which struts themselves constitute resilient
elements for releasing stored energy or are arranged in
co-operation with resilient elements for releasing stored
energy.
11. The device of claim 10, wherein, in a transport configuration
of the water collecting device, the resilient elements are not
loaded (i.e. they are in a minimum energy state), and, in a
ready-for-use configuration, the resilient elements are arranged
such that they are loaded by bringing the water collecting device
into a reduced volume configuration.
12. The device of claim 10, wherein the expansion means comprises,
in addition to the struts, resilient elements that are arranged to
effect a change of angle between adjacent struts; or push sections
of the struts away from each other; or pull sections of the struts
towards each other; and thereby increase the volume of the water
collecting device.
13. The device of claim 9, wherein the energy in the resilient
elements is stored by bending or otherwise deforming the resilient
elements.
14. The device of claim 13, wherein the expansion means comprises
two flat, star-shaped structures arranged inside a pillow-like
water collecting device and pressed apart by a spring.
15. The device of claim 11, wherein the expansion means comprises a
frame of flexible wires that is bendable into a flat shape and when
released expands to a three-dimensional shape supporting the water
collecting device.
16. The device of claim 9, wherein the energy in the resilient
elements is stored by inflating a volume which is part of the
resilient elements.
17. The device of claim 1, wherein the water collecting device
comprises a means for attaching a weight or to attach it to an
external structure.
18. The device of claim 1, further comprising a watertight outer
envelope in which the water collecting device may be arranged.
19. A method for water purification, using a water purification
device that includes a water collecting device having a surface
defining a variable volume, wherein at least part of the surface of
the water collecting device comprises a filter area, the filter
area being permeable to water and allowing water to enter the water
collecting device when the filter area is submerged in water,
wherein the device further comprises a mechanically driven
expansion means for exerting a force for increasing the volume of
the water collecting device and thereby drawing water through the
filter area into the water collecting device, the method comprising
the steps of in the case that the water collecting device is not in
a reduced volume configuration, compressing the water collecting
device such that it is in the reduced volume configuration;
submerging at least the filter area of the water collecting device
in water; releasing the expansion means, allowing the water
collecting device to expand, whereby water enters the water
collecting device through the filter area; when a predetermined
amount of filtered water has accumulated inside the water
collecting device, removing the water collecting device from the
water; draining the accumulated filtered water from the water
collecting device.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to the field of water purification
devices, and in particular to a low-cost, small scale purification
device as described in the preamble of claim 1.
[0003] 2. Description of Related Art
[0004] Access to clean water is an essential human necessity. In
developing countries, in emergency situations, and simply for
outdoor activities, there is a need for simple, lightweight, and
cheap water purification devices. Numerous filtering devices, e.g.
using ceramic filters, multiple water collecting devices with
intervening filters etc. are known.
[0005] U.S. Pat. No. 4,879,030 describes a water purification and
emergency nutrition package. The package comprises a compartment
having a semipermeable membrane which allows it to desalinate
water, and a compartment comprising a mixture of water-soluble
nutrients such as fructose. Once a minimum amount of water has
entered the package, osmotic pressure caused by the water-soluble
nutrients drives the further transfer of water through the
semipermeable membrane. Applicability of the device is limited in
that it can be used only once, in that it does not provide water
alone, but rather a mixture of water and sugars, i.e. nourishment,
and in that it is focused on the desalination of sea water.
[0006] US 2002/008062 A1 discloses a water purifier comprising a
cylindrical body and a piston sliding inside the cylinder. The
piston can be manually withdrawn, sucking water through a filter
and into the device. Pushing the piston back causes the water to be
expelled through the same filter.
BRIEF SUMMARY OF THE INVENTION
[0007] It is therefore an object of the invention to create a water
purification device of the type mentioned initially, which
overcomes the disadvantages mentioned above.
[0008] The water purification device comprises an expandable water
collecting device having a variable volume, wherein at least part
of the surface of the water collecting device comprises a filter
area, the filter area being permeable to water and allowing water
to enter the water collecting device when the filter area is
submerged in water. The device further comprises a mechanically
driven expansion means, for exerting a force for increasing the
volume of the water collecting device and thereby drawing water
through the filter area into the water collecting device.
[0009] For use, the water collecting device is first compressed,
that is, brought into a reduced volume or, ideally, a minimum
volume configuration. This is done e.g. by flattening the water
collecting device, counteracting the force of the expansion means.
While flattening the water collecting device, a clean water outlet
should be opened, allowing air trapped in the water collecting
device to escape. For practical reasons, the water collecting
device will preferably also be delivered and stored in a reduced
volume configuration. The water collecting device is then submerged
in water that requires filtering before consumption, i.e. in a well
or a river or the like. The water collecting device may also be
left to rest on the water, with the filter area being at least
partially submerged, i.e. in contact with the water. The expansion
means is then released, allowing the water collecting device to
expand, whereby water enters the water collecting device through
the filter membrane. When a predetermined amount of filtered water
has accumulated inside the water collecting device, the water
collecting device is removed from the water, and the filtered water
is drained from the water collecting device through an outlet. The
water collecting device is extremely simple to use.
[0010] In situations in which air flows through the filter area
rather rapidly, the water collecting device may expand before being
submerged, by taking in air through the filter. Therefore, in a
preferred embodiment of the invention, a retainer or restraint is
arranged to keep the water collecting device in the reduced volume
configuration until it is submerged. This can be done, for example,
by a bracket or clip reaching around the water collecting device
and holding it in a compressed, reduced volume configuration. The
bracket is slid off or pulled away after submerging the water
collecting device. Alternatively, the water collecting device may
be held in the reduced volume configuration by hand until it is
submerged.
[0011] In a further preferred embodiment of the invention, the
water collecting device comprises an escape valve, e.g. molded from
elastic plastic. This allows one to manually submerge the water
collecting device and then to manually compress the water
collecting device while holding it under water, forcing out
remaining air through the escape valve. The water collecting device
preferably further comprises an outlet for removing clean water
accumulated in the water collecting device; alternatively, the
outlet may be identical to the escape valve, since it is only
necessary to empty the water collecting device through the outlet
valve, whereas the water collecting device is filled through its
filter surface. The outlet may be reclosable.
[0012] In order to ease the submerging, in case some air is trapped
in the water collecting device, the water collecting device
preferably comprises a means for attaching a weight or for being
attached to an external support. Said means can be an eyelet or
grommet, or a piece of string or band attached to the water
collecting device. The band may be made of the same material as the
water collecting device, e.g. a strip of material that is partially
cut from a sheet constituting the water collecting device.
[0013] In a further preferred embodiment of the invention, the
water collecting device comprises holding elements such as straps.
These straps may be attached in, or close to, regions which are
pushed away from each other by the expansion means. In consequence,
an expansion force can be generated or increased by manually
pulling the holding elements.
[0014] The water collecting device is preferably made of a flexible
sheet material shaped to form a container (except for the fact that
the container walls are, at least in the filter areas, permeable).
Preferably, the entire container, or at least three quarters or at
least half of the surface of the container is made of the flexible
sheet material. Thus, the volume of the container is defined by the
flexible sheet material, and the container increases its volume by
inflating and unfolding the sheet material. For example, the water
collecting device comprises two sections of a filter membrane
material that are joined in a watertight manner along edges of the
sections forming in the expanded state of the water collecting
device, a substantially pillow-shaped bag. Or, the water collecting
device may be formed by a cylindrical filter surface, which is
expanded by a helical spring inside the water collecting device. A
multitude of other geometrical shapes which can be folded and
unfolded and in this manner exhibit two different volumes may be
used for the water collecting device.
[0015] In a preferred embodiment of the invention, a substantial
part of the entire surface of the water collecting device is made
of a material serving as the filter. In other preferred
embodiments, at least a quarter or at least half the surface area
of the water collecting device is made of said filtering material.
The filter is permeable to water but impermeable to a group of
water contaminants, reducing the concentration of contaminants in
the filtered water. The filter may be a simple mechanical filter,
inhibiting passage of particles exceeding a predetermined size, but
may also be chemically treated or coated or comprise multiple
layers implementing different water treatment functions and
mechanical functions. The filter pore size is preferably smaller
than one micrometer, and in particular smaller than 0.5 or 0.1
micrometers or less, for filtering out bacteria and preferably also
viruses. The filter, and the water collecting device as a whole,
are preferably made of a biodegradable material. Preferably, the
filter material is treated to make it hydrophilic. As a result, the
minimum pressure, at which the water flow through the filter is
triggered, is decreased.
[0016] The water treatment and mechanical functions implemented by
said multiple layers are, for example: fine pore filtering,
chemical treatment, charcoal filter, stiffening the container walls
of the water collecting device, mechanical reinforcement, or
mechanical protection. Each of these functions may be implemented
by a dedicated layer, or one or more functions may be implemented
by a single layer.
[0017] In further embodiments of the invention, the layer or layers
may be treated by welding them along welding lines or in a
plurality of welding points. This serves to reinforce, join, and/or
to stiffen the layers.
[0018] In a further preferred embodiment of the invention, when the
water collecting device is in a first configuration, comprising a
reduced volume, the expansion means comprises stored energy, and
release of said stored energy causes the volume of the water
collecting device to increase. In other words; the expansion means
comprises, in a loaded state, potential spring energy, which is
used to expand the water collecting device from a substantially
empty, low volume state, to an unloaded or released state in which
it is filled with water, and in which the expansion means is in a
state of minimal energy. In a further preferred embodiment of the
invention, the expansion means is arranged inside the water
collecting device.
[0019] In a preferred embodiment of the invention, the first
configuration corresponds to an essentially flat configuration of
the expansion means, and the increase of volume of the water
collecting device corresponds to the expansion means assuming a
three-dimensional configuration.
[0020] In the reduced volume state, the water collecting device is
well suited for efficient storage and transport. Thus, the water
collecting device will preferably be produced to be stored in a
reduced volume state, e.g. pre-folded, with the faces of the water
collecting device being folded inwards or outwards.
[0021] The expansion means preferably comprises at least one
resilient element which releases stored energy by deforming, i.e.
by changing its shape, in particular by at least one of the
following: bending, unbending, expanding, and contracting.
[0022] The expansion means preferably comprises one or more struts
that form a frame supporting the water collecting device and
transferring and distributing the forces for expanding the water
collecting device to the water collecting device surface. The
struts themselves constitute resilient elements for releasing
stored energy and/or are arranged in co-operation with separate
resilient elements for releasing stored energy. A strut may, for
example, be an elongated, stick-like body, or a section of a flat
but elastic sheet of material, or a perforated sheet of elastic
material.
[0023] In the case in which the expansion means comprises, in
addition to the struts, separate resilient elements, these
resilient elements may be arranged, in order to increase the volume
of the water collecting device: [0024] to effect a change of angle
between adjacent struts; or [0025] to push sections of the struts
away from each other; or [0026] to pull sections of the struts
towards each other.
[0027] For example, the expansion means may comprise two flat,
star-shaped structures, e.g. made of a plastic sheet, arranged
inside a pillow-like bag or container and pressed apart by a
spring. Or, in another preferred embodiment of the invention, the
expansion means comprises a frame of flexible wires that can be
bent into a flat shape and then expands to a three-dimensional
shape.
[0028] The energy stored in the resilient elements may be stored by
deforming the elements, or by providing, as part of the elements,
airtight volumes which can be inflated. Inflating the volumes
causes them to expand, providing a resilient element. For example,
the struts may be formed as inflatable volumes. In order to use the
purification device, the struts are inflated, e.g. with a simple
pump, establishing the tension which causes the struts to expand
the water collecting device. Thus, driving the expansion
mechanically also includes the use of such pneumatic energy
storage, which is converted to mechanical forces driving the
expansion.
[0029] In another preferred embodiment of the invention, the energy
for expanding the water collecting device is stored by a resilient
element which has a porous or sponge-like structure. Such an
element also may comprise mechanical water filtering and/or
chemical purification functions.
[0030] In yet a further preferred embodiment of the invention, the
expansion means is manually activated, for example by directly
driving the expansion, or by storing energy in a resilient element,
e.g. by manually deforming (compressing or loading) a spring or
another elastic element. The elastic element then gradually relaxes
while the water collecting device expands.
[0031] In a further preferred embodiment of the invention, the
water collecting device comprises a supply of alimentary additives
such as nutrients or vitamins. The additives are dissolved or
diluted or mixed with the filtered water collecting in the water
collecting device.
[0032] In a further preferred embodiment of the invention, the
purification device comprises a watertight outer envelope in which
the water collecting device may be arranged. The outer envelope may
be welded or otherwise attached to the water collecting device, or
may be a loose component. If the outer envelope is attached to the
water collecting device, it may be either put over the water
collecting container or pulled back to expose the water collecting
device for filtering (when immersed in water) or for cleaning the
filter area. When the outer envelope is arranged to contain the
water collecting device, it can preferably be closed around the
water collecting device, e.g. by a Minigrip.RTM.-like sealing
mechanism. In another application of the invention, the filtration
device is not submerged as a whole, but the outer envelope is
filled with water, and the water collecting device expands within
the outer envelope, drawing in the water from the outer
envelope.
[0033] The volume of the water collecting device is preferably in
the range of 0.5 liters to 2 liters, with its dimensions being, for
example, 150 by 80 by 40 millimeters or more.
[0034] Further preferred embodiments are evident from the dependent
patent claims. Features of the method claims may be combined with
features of the device claims and vice versa.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The subject matter of the invention will be explained in
more detail in the following text with reference to preferred
exemplary embodiments which are illustrated in the attached
drawings, in which:
[0036] FIG. 1 schematically shows the use of a water collecting
device for water purification according to the invention;
[0037] FIG. 2 shows an expansion means of a first embodiment of the
invention in a transport and storage configuration;
[0038] FIG. 3 shows said expansion means in a ready-to-use
configuration;
[0039] FIG. 4 shows said expansion means in a ready-to-use
configuration inside the corresponding water collecting device;
[0040] FIG. 5 shows a frame of a further embodiment of the
invention in a reduced volume configuration;
[0041] FIG. 6 shows said frame in an expanded configuration;
[0042] FIG. 7 shows said frame inside the corresponding water
collecting device;
[0043] FIG. 8 shows a water collecting device comprising a helical
expansion means; and
[0044] FIG. 9 shows a water collecting device with a manually
operable expansion means.
[0045] The reference symbols used in the drawings, and their
meanings, are listed in summary form in the list of reference
symbols. In principle, identical parts are provided with the same
reference symbols in the figures.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0046] FIG. 1 schematically shows the use of a water collecting
device 1 for water purification according to the invention. At the
top of FIG. 1 there is a representation of the water collecting
device 1 in a reduced volume state, right after submerging the
water collecting device 1. The water collecting device 1 comprises
a filter membrane 2, which constitutes the walls of the water
collecting device 1 itself, and a frame made up of struts 3. A
resilient element 4, such as a spring, is arranged to push opposing
sides of the frame apart, increasing the volume of the water
collecting device 1. An outlet 6 serves to extract the filtered
water. The outlet 6 is either openable and reclosable, or has a
valve function which allows water and air to exit the water
collecting device when pressure is applied to the water collecting
device. Also shown are optional straps 14 for manually driving or
assisting in the expansion of the device.
[0047] When the water collecting device 1 is submerged, the spring
4 is released. The spring 4 gradually increases the volume of the
water collecting device 1, as water flows though the filter
membrane 2 into the water collecting device 1. When the maximum
volume has been reached (bottom part of FIG. 1), the water
collecting device 1 can be retrieved and emptied by means of the
outlet 6.
[0048] Since, for this embodiment, all surfaces of the water
collecting device are made of the filter material 2, the water
collecting device 1 should be entirely submerged in order to
prevent air from being sucked in through the filter membrane 2. For
other embodiments, in which only part of the water collecting
device surface works as a filter, it is allowable to submerge only
those filter surfaces. Along some of the edges 5 of the water
collecting device 1, the filter membrane 2 may be welded together,
for example, at front and back end sections of the water collecting
device 1. One of the welds shown comprises an eyelet 8 for
attaching the device to a weight or an external support (not shown)
for submerging the water collecting device 1.
[0049] For typical filter membranes, pressure differences of
typically 10 mbar or more are sufficient to drive the flow of water
through the membrane. Given a water collecting device 1 in the
shape of a 20 cm by 20 cm pillow, that is, with an active surface
of 800 cm.sup.2, a force of ca. 40 N will suffice to push opposing
sides of the water collecting device 1 apart and to create the
pressure difference that drives the flow of water into the water
collecting device 1. Depending on the exact filter material, the
device will take between ca. 10 minutes and less than one minute to
filter one litre of water.
[0050] FIG. 2 shows an expansion means of a first embodiment of the
invention in a transport and storage configuration. The expansion
means comprises two support structures 7 comprising several struts
3, and two O-shaped springs 9 serving as resilient elements 4. The
support structures 7 themselves may also exhibit a certain
resilience. Both the support structures 7 and the O-shaped springs
9 are made of a plastic material, preferably from sheets of
material, such that they exhibit a certain stiffness within the
plane of the sheet, and a comparatively larger elasticity in other
directions. During transport and storage, the O-shaped springs 9,
preferably, are in an unloaded state, which prevents them from
losing their resilience. The O-shaped springs 9 and the support
structures 7 are folded flat, preferably inside a corresponding
water collecting device. In order to use the water collecting
device, the O-shaped springs 9 and support structures 7 are
unfolded, whereby the O-shaped springs 9 snap and/or lock into a
position in which they press the support structure 7 away from each
other. FIG. 3 shows said expansion means in the resulting state,
that is, in a ready-to-use configuration. This snapping action is
accomplished, e.g. by pulling flat sections of the support
structures 7 and the O-shaped springs 9 against one another by
means of rubber bands 12. In the folded state, said flat sections
of the support structures 7 and the O-shaped springs 9 are at right
angles to one another and the rubber bands 12 going around both of
them are elongated. In the unfolded state, said flat sections lie
flat on each other and the rubber bands 12 are shortened. The
arrangement will remain in this configuration unless a shearing
force is applied. A vertical compression force pushing the support
structures 7 against each other compresses the O-shaped springs 9
and brings the water collecting device 1 into the reduced volume
state. FIG. 4 shows said expansion means in a ready-to-use
configuration inside the corresponding water collecting device.
Also shown are optional straps 14 for manually driving or assisting
in the expansion of the device.
[0051] FIG. 5 shows a frame of a further embodiment of the
invention in a reduced volume configuration. The frame is
constituted of a set of struts 3 made of a flexible and elastic
material, preferably metal or a plastic that is not subject to
material fatigue. In FIG. 5, the frame is compressed by forcing the
two middle struts 3 together. FIG. 6 shows said frame in a released
or expanded configuration.
[0052] FIG. 7 shows said frame inside the corresponding water
collecting device 1, again in the expanded configuration. The frame
defined by the struts 3 is arranged inside the volume formed by the
membrane 2, which may be welded together at the edges by welding
seams 18. If the volume is expanded by the resilience of the struts
3, then no further expansion means is mandatory, otherwise, a
spring or other expanding device for pushing selected struts 3
apart may be arranged inside the volume, as in the embodiment of
FIG. 1. Straps 14 are attached to the membrane and preferably also
to struts 3. An optional watertight outer envelope 16 may be
attached to the device 1, arranged in an extended position as shown
in the figure. The outer envelope 16 may be folded around the
collecting device 1 (as indicated by arrows) and then closed by a
closing means or closure 17, e.g. a Minigrip.RTM. seal. Such an
outer envelope 16 may of course be added to any of the other
embodiments as well. The outer envelope 16 may also be detached
from the device 1.
[0053] FIG. 8 shows a cylindrical water collecting device 1
comprising a helical spring 10 in an expanded state. In the reduced
volume state, the helical spring 10 is compressed to an essentially
planar configuration, and the filter membrane 2 folds
accordingly.
[0054] FIG. 9 shows a water collecting device 1 with a manually
operable expansion means in a half-filled state and a full (maximum
volume) state. The device comprises rigid rings 11 attached to the
inside of the (filter membrane) surface 2 of the device 1. When
pulled apart by the expansion means, the rings 11 define a
cylindrical volume which is spanned by the membrane 2. The
mechanically driven expansion means is constituted by a rod 12
which is guided through a cap 13 attached to a first end of the
device, and pushes an opposing end of the device away from the
first end. A resilient element such as a spring, e.g. an O-shaped
spring 9, may be arranged to be compressed by the rod 12 when the
rod 12 is pushed into the device. After this, the spring 9 expands
gradually as water enters the device through the filter 2. When the
spring 9 is expanded, the rod 12 can be pushed in again, repeating
the process until the device 1 is full. In an alternative
embodiment, part or all of the surface of the collecting device 1
is elastic, and is tensioned when the rod 12 is pushed into the
device. The cap 13 preferably comprises a screw mechanism or a
ratchet mechanism which prevents the rod 12 from sliding out after
being pushed in. If a screw mechanism is used, then one part of the
cap can be turned with respect to the other one, or the rod can be
turned with respect to the rest of the device in order to create
the linear movement of the rod with respect to the cap when
expanding the device 1. The outlet, optional straps etc. are
omitted in FIG. 9 for clarity.
[0055] While the invention has been described in present preferred
embodiments of the invention, it is distinctly understood that the
invention is not limited thereto, but may be otherwise variously
embodied and practised within the scope of the claims.
LIST OF DESIGNATIONS
[0056] 1 water collecting device [0057] 2 filter membrane [0058] 3
strut [0059] 4 resilient element [0060] 5 edge [0061] 6 outlet
[0062] 7 support structure [0063] 8 eyelet, grommet [0064] 9
O-shaped spring [0065] 10 helical spring [0066] 11 ring [0067] 12
rubber band [0068] 13 cap [0069] 14 strap [0070] 15 rod [0071] 16
envelope [0072] 17 closure [0073] 18 welding seams
* * * * *