U.S. patent application number 10/767272 was filed with the patent office on 2004-09-23 for pressing iron having an electro-osmotic pump.
This patent application is currently assigned to SEB S.A.. Invention is credited to Compeau, Jean Louis, Debourg, Jean Pierre.
Application Number | 20040181979 10/767272 |
Document ID | / |
Family ID | 32696207 |
Filed Date | 2004-09-23 |
United States Patent
Application |
20040181979 |
Kind Code |
A1 |
Compeau, Jean Louis ; et
al. |
September 23, 2004 |
Pressing iron having an electro-osmotic pump
Abstract
A clothes iron appliance composed of a water reservoir, a steam
chamber, and an electro-osmotic pump having a porous body disposed
to pump water from the reservoir to the steam chamber.
Inventors: |
Compeau, Jean Louis; (Saint
Quentin Fallavier, FR) ; Debourg, Jean Pierre; (Lyon,
FR) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.
624 NINTH STREET, NW
SUITE 300
WASHINGTON
DC
20001-5303
US
|
Assignee: |
SEB S.A.
Ecully
FR
|
Family ID: |
32696207 |
Appl. No.: |
10/767272 |
Filed: |
January 30, 2004 |
Current U.S.
Class: |
38/77.1 |
Current CPC
Class: |
F04B 17/00 20130101;
B01D 71/027 20130101; D06F 75/18 20130101; B01D 61/42 20130101;
B01D 69/12 20130101 |
Class at
Publication: |
038/077.1 |
International
Class: |
D06F 075/22; D06F
075/10; D06F 075/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2003 |
FR |
FR-03 01031 |
Claims
What is claimed is:
1. A clothes iron appliance comprising: a water reservoir; a steam
chamber; and an electro-osmotic pump comprising a porous body
disposed to pump water from said reservoir to said steam
chamber.
2. The appliance of claim 1 wherein said porous body has a
thickness dimension in the direction in which water is pumped, and
a cross-section perpendicular to the thickness dimension, and the
cross-section has dimensions greater than the thickness
dimension.
3. The appliance of claim 1, wherein said porous body is composed
of a bed composed of fine grains.
4. The appliance of claim 3 wherein the fine grains are constituted
by alluvial sand having a grain size not greater than 0.2 mm.
5. The appliance of claim 3 wherein the fine grains are of a
siliceous material.
6. The appliance of claim 3 wherein the fine grains include grains
of an ion exchange resin.
7. The appliance of claim 1 wherein said pump further comprises an
enclosure made of plastic material and containing said porous body,
and two electrodes placed in electrical communication with
respective opposite faces of said porous body.
8. The appliance of claim 7 wherein each of said electrodes is made
of stainless steel or of titanium and is provided with through
holes.
9. The alliance of claim 7, wherein said pump further comprises
porous membranes interposed between said body and said
electrodes.
10. The appliance of claim 1 wherein said appliance further
comprises a source of direct current for said pump, said source
comprising a transformer or a switch mode power supply having a
galvanic isolation.
11. The appliance of claim 1 wherein said pump is constituted by a
cassette which is installed in said reservoir in an easily
removable manner, and said appliance further comprises a conduit
connected to convey water from an outlet of said pump to an inlet
of said steam chamber.
12. The appliance of claim 11 wherein said appliance further
comprises a shunt provided with a calibrated orifice and connected
between a point of said conduit that is above said steam chamber
and a point in an upper region of said reservoir.
13. The appliance of claim 11, further comprising a spray nozzle
and a 3-way valve connected between said conduit and said nozzle
for supplying water from said pump to said nozzle.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to steam pressing irons, and
similar appliances such as steam wrinkle removers. In such
appliances, water is conveyed slowly from a reservoir to a steam
chamber in which water is converted into steam. More particularly,
the invention concerns means for conveying the water into the steam
chamber.
[0002] The most well known devices for this purpose are drip
devices functioning by gravity, but they have the drawback that
they cease to function when the pressure of steam in the steam
chamber becomes higher than that of the column of water available
above the drip device.
[0003] One solution to this problem consists in adapting an
electromagnetic piston or membrane pump actuated by an
electromagnet or an electric motor. Such devices are described, for
example, in French patents numbers FR2368862 and FR2690932. Also
known are rotary pumps such as centrifugal pumps as described in
French patent number FR2688013 as well as peristaltic pumps, an
example of which is disclosed in French patent number FR2691210,
less commonly used.
[0004] These types of pumps have proven satisfactory with regard to
flow rate and pressure. However, they also generate noise and
vibrations, their flow rate is not easily variable, which leads
them to operate in bursts, and they are relatively costly.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention provides a household electric
appliance containing a water reservoir that may be filled with tap
water and that is equipped with a pump that is silent, economical
and durable to transfer water from the reservoir toward the steam
chamber, with a continuous flow rate that is easily adjustable with
precision and is interruptible, as well as having a sufficient
pressure to overcome the counter pressure generated in the steam
chamber during ironing.
[0006] Primarily, the invention is embodied in an ironing appliance
having a water reservoir and a pump for transferring water from the
reservoir toward the steam chamber, wherein the pump is an
electro-osmotic pump.
[0007] An electro-osmotic pump, as contemplated by the present
invention, is a device having a first compartment that is normally
connected to the water reservoir or that forms a part of this
reservoir, and a second compartment connected to the steam chamber
in which water transferred by the pump is converted into steam, the
two compartments being separated by a porous solid body. Each
compartment is furnished with an electrode in proximity to the
porous body, the electrodes allowing water to flow therepast.
[0008] Thus, when a voltage is applied between the electrodes, a
flow of water is created from the first compartment toward the
second compartment and supplies the steam chamber. The principle of
an electro-osmotic pump is described for example in U.S. Pat. No.
3,143,691. This document cites the pressures obtained with water,
which reach the equivalent of a height of water of 11 mm per volt
applied between the electrodes. However, the device described only
transfers water from one chamber to another without flowing in a
circuit, or serves to detect a pressure or flow rate.
[0009] Uses are known in fields that are radically different from
that of the present invention. For example, French patent FR1446109
describes numerous devices using a pump of this nature, but with
non-aqueous liquids. Several patents also describe medical uses for
distributing medications in very small quantities, uses in
chromatography to cause an electrolyte to circulate in a column,
and uses in fluidics with low flow rates as in U.S. Pat. No.
6,012,902.
[0010] All of these uses concern movements of electrolytes or
diverse solutions having characteristics far removed from running
water, generally in fields that are very sophisticated and that
involve low flow rates.
[0011] French patent FR2467178 describes a water purifier using
electro-osmotic pumps, but the pumps used only operate if the water
is purified, by resin devices that demineralize the water.
[0012] None of the above-cited documents envisions or suggests the
utilization of such a pump in a household electric appliance, or
even less in a pressing iron. However, an iron provided with an
electro-osmotic pump performs particularly well and is particularly
quiet.
[0013] The pump is placed between the reservoir and the steam
chamber. Its water inlet communicates with the reservoir or is
located within the reservoir, while its outlet is connected to the
steam chamber.
[0014] According to one embodiment, the pump is constituted by an
enclosure made of electrically non-conductive plastic, containing a
porous body composed of grains of fritted glass, in the form of a
disc occupying the entire cross-section of the enclosure. The fluid
inlet and outlet are arranged at respective opposite sides of the
porous disc. Two electrodes are placed to one side and the other of
the disc, in contact with the fritted glass and in the path of the
fluid. The pump is actuated by application of a direct voltage
between the electrodes, of the order of 10-200 volts. Water is
displaced, in this case of a siliceous covering of the disc, from
the anode toward the cathode, the flow/pressure characteristic
being linear and being directly dependant on the applied
voltage.
[0015] Preferably, the cross-section of the porous body
corresponding to the water passage has dimensions greater than the
thickness of the porous body.
[0016] Specifically, the diameter of the disc is greater than its
thickness. This thus avoids having a localized bubble in the porous
body interrupt the passage of the electric current and the
operation of the pump. In effect, a possible gas bubble, generated
by the electrodes and trapped in the porous body, cannot have a
diameter greater than the thickness of the porous body and thus
cannot obstruct the entire passage cross-section for the water and
the electric current.
[0017] In a preferred embodiment, the porous body is constituted by
a bed of grains of very fine alluvial sand having a grain size of
0.2 mm or less.
[0018] Thus, fritted glass is replaced by the sand. This provides
an economical form of construction of the medium in which the
electro-osmosis is produced. Preferably, the porous body is of a
siliceous nature, such as a quartz sand.
[0019] The bed of grains is maintained in an enclosure made of
plastic by the electrodes, which are preferably made of stainless
steel and provided with holes, the electrodes being placed on two
flat faces of the bed.
[0020] Preferably, the electrodes are made of sheets of stainless
steel that are perforated and expanded.
[0021] The electrodes do not significantly interfere with the
passage of water in the pump.
[0022] Preferably, the electrodes are separated from the bed of
grains, which they retain, by porous membranes.
[0023] The membranes aid retention of the sand so that the
perforations in the electrodes do not have to be particularly
small.
[0024] The electric supply of the pump, for reasons of safety,
includes a transformer or a switch mode power supply including a
galvanic isolation.
[0025] The invention also permits a linear variation of the flow
rate by modification of the direct voltage applied between the
electrodes.
BRIEF DESCRIPTION OF THE DRAWING
[0026] FIG. 1 is an elevational, cross-sectional view of an iron
according to the invention.
[0027] FIG. 2 is a cross-sectional detail view, to a larger scale
than FIG. 1, of a preferred embodiment of a pump according to the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] According to a preferred embodiment, shown in FIG. 1, a
steam iron 1 includes an integrated water reservoir 11, and a
soleplate 12 heated by a heating body 13 furnished with a heating
element 131. A steam chamber 132, closed by a plate 133, is
arranged in heating body 13. Steam produced in chamber 132 escapes
through steam holes 121 in the ironing face of soleplate 12.
[0029] An electro-osmotic pump 2 is installed at the rear of water
reservoir 11. Preferably, the pump is present in the form of a
cassette 21 introduced into the bottom of reservoir 11 from the
rear of the iron, before closing the heel of the iron by the heel
piece 14 during fabrication of the iron. A sealing joint 211
assures a liquid tight seal between the cassette and the wall of
reservoir 11. As a result of this arrangement, the pump is easily
removable and replaceable when it eventually becomes ineffective.
At the rear of the iron, the pump remains immersed in water even
when the iron is placed on its heel piece 14.
[0030] As shown in FIG. 2, pump 2 has a water outlet 212 that is
accessible to the exterior to the reservoir. Water outlet 212 is
connected to a point 134 at which water is injected into steam
chamber 132 through a conduit 15. Conduit 15 has at a high point
along its path a shunt 151 toward a high point of reservoir 11.
Shunt 151 is provided with a calibrated orifice 152, opening into
the high point of reservoir 11, with a diameter of several tenths
of a millimeter, which is small relative to the diameter of conduit
15.
[0031] With this arrangement, introduction of air through orifice
152 interrupts any siphoning from reservoir 11 toward steam chamber
132 when the iron ceases being used but remains with the soleplate
flat on the ironing surface. In effect, this siphon action,
although very slow due to the substantial loss of head in pump 2
when it is halted, would be possible since reservoir 11 is placed
higher than the point 134 at which water is injected into steam
chamber 132. When the pump is in operation, the flow of water
toward reservoir 11 through orifice 152 is negligible.
[0032] Further referring to FIG. 2, pump 2 includes an envelop 21
in the form of a cassette, divided vertically into two compartments
213, 214. These two compartments are separated by a porous body 220
that may be in the form of a disc. Preferably, the disc has a
circular, cylindrical form, with an axis that is vertical in the
plane of FIG. 2. According to a preferred embodiment of the
invention, body 220 has a diameter of the order of 40 mm, and a
thickness of 10 mm. However, disc 220 can have any other outline
that is compatible with the internal configuration of the
reservoir. Disc 220 is enclosed laterally by a ring 221, preferably
made of electrically insulating plastic material, this ring
facilitating fabrication of the body. Ring 221 is clamped in
cassette 21 by internal parts 215, which helps to assure the
formation of a fluid tight seal around ring 21 between compartments
213 and 214.
[0033] Porous body 220 is preferably constituted by a bed of
alluvial siliceous sand having a grain size of less than 0.2 mm.
Each exposed face of disc 220 is covered with a membrane 22 and an
electrode 223. Each membrane 22 is permeable to water, and may be
made, for example, of filter paper, and each membrane 22 is in
contact with body 220. Each electrode 223 overlies its associated
membrane 222 and may be made of an expanded stainless steel sheet
that serves to retain the shape of the porous body. Each electrode
is connected by a soldered connection 224 to a pin, such as 216,
that passes through the wall of cassette 21 that is outside
reservoir 11. According to another form of construction, the
electrodes can be made of an expanded titanium sheet, preferably
having a platinum coating.
[0034] A connector (not shown) connects pins 216 to a direct
current source, with the lower electrode being the anode and the
upper electrode being the cathode. The direct current source can be
disposed in the handle of the iron and can be a transformer or a
switch power supply including a galvanic isolation with respect to
the power mains and the body of the iron. Voltage applied between
the electrodes during operation of pump 2 can be regulated by the
user, from 10 to 200 volts.
[0035] Lower compartment 213 of pump 2 is open at the bottom and
laterally to communicate with the interior of reservoir 11 so that
water contained in reservoir 11 will enter compartment 213 and
moisten body 20 by capillarity. Upper compartment 214 is coupled to
pump outlet 212.
[0036] When the iron is ready to be used and the user wishes to
produce steam, he adjusts the output voltage of the constant
current source by acting on a suitable button or switch that can be
graduated in terms of steam flow rate. The voltage applied between
electrodes 223 provokes an ion current along the walls of the
capillary network constituted by the grains of sand, thus
entraining molecules of water in the direction of the cathode in
the case of a porous siliceous body. Water passes from reservoir 11
into compartment 213 then through body 220, into compartment 214
and then out through outlet 212, which may be in the form of a
nipple, and finally through conduit 15, in order to reach point 134
where water is injected into the steam chamber.
[0037] The thickness of the porous body being constant, the water
flow rate is directly proportional to the voltage applied between
the electrodes. If there is a slight liberation of gas at the
electrodes due to electrolysis of the water, the gas forms into
bubbles. The diameter of the bubbles cannot exceed the thickness of
the disc constituting body 220, which thickness is less than the
diameter of the body. Therefore, the bubbles cannot completely
interrupt the ion current between the electrodes and can thus not
cause an undesired blockage of pump operation. On the contrary,
these bubbles will be entrained and evacuated along with the water
current.
[0038] The device as described produces, when supplied with a
direct voltage of 200 volts, a water flow rate of around 20 g/min
under a pressure of several tens of millibars, much greater than
the column of water available in the iron above injection point
134, fully sufficient to overcome the counter pressure due to the
steam produced in chamber 132 and to assure easy ironing. Since
there is no mechanical moving part, the pump operation is
completely silent.
[0039] When the user finishes ironing, and if he allows the iron to
cool while left to rest on soleplate 12, conduit 15 empties slowly
through injection point 134. Air inlet 152 prevents water from
being inadvertently siphoned out of reservoir 11, through pump
2.
[0040] In a related form of construction, conduit 15 has, upstream
of shunt 151, a 3-way valve that permits, under control of the
user, the supply of water to a sprayer 16 situated at the front of
the iron in order to moisten items to be ironed.
[0041] According to another form of construction, porous body 222
is constituted by a bed of mixed grains including grains of ion
exchange resin having a small grain size. The polarity of the
direct current source is selected as a function of the nature of
the majority of the grains. The porous body has the double function
of a capillary substrate for the electro-osmosis, and a
demineralizing system. Water outlet 212 and the associated end of
conduit 15 are modified to facilitate a rapid connection suitable
for a relatively frequent replacement of the cassette necessitated
by the limited lifetime of such resins.
[0042] By these means, there is obtained an ironing appliance
having a pump that is silent, economical, reliable and durable for
transferring water from the reservoir toward the steam chamber with
an easily regulatible constant flow rate and with a pressure
sufficient to overcome the counter pressure generated in the steam
chamber as a result of the generation of steam during ironing.
[0043] This application relates to subject matter disclosed in
French Application number FR 03 01031, filed on Jan. 30, 2003, the
disclosure of which is incorporated herein by reference.
[0044] While the description above refers to particular embodiments
of the present invention, it will be understood that many
modifications may be made without departing from the spirit
thereof. The accompanying claims are intended to cover such
modifications as would fall within the true scope and spirit of the
present invention.
[0045] The presently disclosed embodiments are therefore to be
considered in all respects as illustrative and not restrictive, the
scope of the invention being indicated by the appended claims,
rather than the foregoing description, and all changes which come
within the meaning and range of equivalency of the claims are
therefore intended to be embraced therein.
* * * * *