U.S. patent application number 09/816659 was filed with the patent office on 2001-11-01 for physical-chemical scale reducing device with flake disintegrating grid for a pressing iron.
Invention is credited to Hipp, Edgar, Horn, Herbert.
Application Number | 20010034959 09/816659 |
Document ID | / |
Family ID | 7636306 |
Filed Date | 2001-11-01 |
United States Patent
Application |
20010034959 |
Kind Code |
A1 |
Horn, Herbert ; et
al. |
November 1, 2001 |
Physical-chemical scale reducing device with flake disintegrating
grid for a pressing iron
Abstract
A steam iron composed of: a metal heating body containing a
chamber that has a steam generating zone; a water flow path in
communication with the chamber, the water flow path including a
compartment containing a quantity of a scale reducing agent that is
contacted by water flowing along the path before the water reaches
the chamber; and a screen made of a metal different from that of
the heating body and disposed in proximity to the steam generating
zone at a location to be traversed by steam generated in the steam
generating zone.
Inventors: |
Horn, Herbert; (Erbach,
DE) ; Hipp, Edgar; (Limonest, FR) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.
624 Ninth Street, N.W.
Washington
DC
20001
US
|
Family ID: |
7636306 |
Appl. No.: |
09/816659 |
Filed: |
March 26, 2001 |
Current U.S.
Class: |
38/77.8 |
Current CPC
Class: |
D06F 75/10 20130101;
D06F 75/18 20130101; D06F 75/14 20130101 |
Class at
Publication: |
38/77.8 |
International
Class: |
D06F 075/14 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 27, 2000 |
DE |
100 14 815.8 |
Claims
What is claimed is:
1. A steam iron comprising: a metal heating body containing a
chamber that has a steam generating zone; means defining a water
flow path in communication with said chamber, said water flow path
including a compartment containing a quantity of a scale reducing
agent that is contacted by water flowing along the path before the
water reaches said chamber, said scale reducing agent being
obtained by cross-linking or hardening a silicone elastomer of an
organosilicic system that is permeable to water vapor and having an
active hydrophilic material and a polyorganosiloxane composition;
and a screen made of a metal different from that of said heating
body and disposed in proximity to said steam generating zone at a
location to be traversed by steam generated in said steam
generating zone.
2. Iron according to claim 1 wherein the active hydrophilic
material is selected from among the metaphosphates of sodium or
potassium.
3. Iron according to claim 1 wherein said screen is tightly gripped
between two walls of said chamber.
4. Iron according to claim 1 wherein said screen is coated with a
layer of gold.
5. Iron according to claim 1 wherein said screen is made of
stainless steel.
6. Iron according to claim 1 wherein said screen is an expanded
metal.
7. Iron according to claim 1 further comprising a tube containing
said scale reducing agent and having at least one end through which
the active material is dispensed.
8. Iron according to claim 7 wherein said water flow path includes
a reservoir and said tube is disposed in said reservoir.
9. Iron according to claim 1 wherein said screen is made of
stainless steel coated with a layer of gold.
10. Iron according to claim 9 wherein said screen is an expanded
metal.
11. Iron according to claim 1 wherein said screen and said heating
body are in contact with one another and the different metals of
said screen and said heating body cause an electric potential
difference to be present between said screen and said heating body.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to steam irons in which steam
is produced in a quasi-instantaneous manner. These appliances have
a useful life that is limited by the build up of scale in the steam
chamber.
[0002] Numerous devices for reducing the occurrence of scale in an
iron have been proposed. One of the most successful
physical-chemical systems diffuses a phosphorated product into
water before the water is vaporized in order to impede
crystallization of the scale in a hard form and to permit its
removal by the steam flow. French patent FR 2 757 364 describes an
embodiment of such a device where the diffusion of sodium
hexametaphosphate (SHMP), which is highly soluble, is controlled by
a silicone matrix placed in the water circuit. However, it has been
noted that the scale that is formed tends to partially agglomerate
under the action of the steam and detaches in the form of flakes
that are friable but that are evacuated in bunches that stain the
fabric being ironed.
[0003] The particles can be retained in the steam chamber by a
metal screen as suggested in the German patent DE 3006783 or the
Japanese patent 60160999. A screening can equally be produced in a
manner disclosed in the French patent FR 2 696 197 where a grid
intended to improve the vaporization has its edges raised in the
form of bowl. However, the utilization of a screening grid alone
eventually provokes blockages of the steam chamber by very hard
scale, which cannot be evacuated.
BRIEF SUMMARY OF THE INVENTION
[0004] The present invention has as an object a scale reducing
device that will prolong the useful life of a steam iron while
permitting regular evacuation of scale in a powder form powder that
is invisible to the user and will not stain articles being ironed,
while preventing obstruction of the chamber as well as of the steam
vaporization channels, including the steam delivery holes in the
iron soleplate.
[0005] The above and other objects are achieved, according to the
invention, by a steam iron composed of: a metal heating body
containing a chamber that has a steam generating zone; means
defining a water flow path in communication with the chamber, the
water flow path including a compartment containing a quantity of a
scale reducing agent that is contacted by water flowing along the
path before the water reaches the chamber, the scale reducing agent
being obtained by cross-linking or hardening a silicone elastomer
of an organosilicic system that is permeable to water vapor and
having an active hydrophilic material and a polyorganosiloxane
composition; and a screen made of a metal different from that of
the heating body and disposed in proximity to the steam generating
zone at a location to be traversed by steam generated in the steam
generating zone.
[0006] The scale reducing agent could be fabricated in the manner
disclosed in French patent FR 2 757 364.
[0007] Preferably, the active hydrophilic material is selected from
among the metaphosphates of sodium or of potassium. It has been
found that in the case of steam irons according to the present
invention, no visible flakes exit through the steam delivery holes
of the soleplate even when the screen has holes with a hydraulic
diameter of the order of two millimeters. Surprisingly, scale does
not accumulate in the steam chamber, or in the steam flow
channels.
[0008] Preferably, the screen is fitted, or gripped, or clamped,
tightly between two walls of the steam chamber of the pressing
iron.
[0009] The process that permits the scale to be present in the form
of a very fine powder that is not visible at the outlet of the iron
is not clearly understood. Possibly, the friable flakes that detach
from the steam generating zone are retained and rub against the
screen, which breaks them into the very fine particles. Possibly,
the scale that is deposited on or against the screen is broken up
by thermal expansion and contraction of the screen. It is also
possible that there is an unknown phenomenon resulting from the
difference in electrical potential caused by the different
characteristics of the metal making up the heating body and the
different metal of the screen. This difference in electric
potential could have an effect due to the good electric connection
resulting from the tight gripping of the screen in the heating
body.
[0010] Preferably, the screen is coated with a gold layer. This
layer protects the screen and prevents it from rusting or
corroding. It is also noted that the gold gives rise to a large
electric potential difference with a heating body made of aluminum.
According to another possibility, the screen can be made of
stainless steal.
[0011] In either case, the screen is protected from oxidation
phenomena and the appearance of a potential difference with a
heating body of aluminum is promoted.
[0012] Also preferably, the screen is made of an expanded metal
that is better able to break up the scale which comes to deposited
on or against the screen.
[0013] Preferably, the scale reducing agent is contained in a tube
and librates its active ingredients through at least one open end
of the tube.
[0014] The silicone can be in form of matrix molded into the tube
without requiring another mold. The active material is librated
with a kinetic of the order of unity. This means that the active
material is librated at a substantially rate, at least when the
temperature of the matrix remains substantially constant. The
active material is librated through a progressive front of cracks
in the matrix, which coincides with the cross section of the tube
so that the liberation of active material is thus perfectly
controlled.
[0015] Preferably, the tube containing the scale reducing agent is
placed in the water reservoir of the iron. The scale reducing agent
can be present in a quantity sufficient to assure a good
functioning of the system during the entire expected useful life of
the iron, or can be renewable. Placement in the water reservoir is
simplified when the matrix is molded within the tube.
BRIEF DESCRIPTION OF THE DRAWING
[0016] FIG. 1 is a simplified side cross-sectional view, along line
I-I of FIG. 2, of a pressing iron constructed according to the
present invention.
[0017] FIG. 2 is a plan view of the soleplate of the iron shown in
FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0018] A preferred embodiment of a steam pressing iron according to
the invention is shown in FIGS. 1 and 2. This iron is composed of a
soleplate 1 having a steam generating chamber 2, a water reservoir
3, a droplet delivery system 4 permitting water to be supplied at a
desired rate to chamber 2 from reservoir 3, and a housing, or
casing, 5 that includes a handle for grasping the iron.
[0019] Reservoir 3 is formed by two pieces 300 and 301 and has a
filling opening 302 that can be closed by a sliding cover 303. A
tubular element 304 having a constant cross-section perpendicular
to the plane of FIG. 1 is disposed at the interior of reservoir 3.
Element 304 is filled with a molded silicone elastomer matrix 305
containing SHMP in the form of a solid dispersion. One or both ends
of element 304, which ends are parallel to the plane of FIG. 1, are
open to expose matrix 305 to water within reservoir 3. Element 304
is installed to be in contact with water in reservoir 3.
[0020] Soleplate 1 contains a heating body 100 made of aluminum and
defining the walls of steam generating chamber 2. Soleplate 1
further has a tubular resistive heating element 101, a closing
plate 102 and a cap, or liner, 103 that is in thermal communication
with heating body 100. Closing plate 102 constitutes the upper
wall, or cover, of chamber 2. Liner 103 constitutes the external
ironing surface of the iron and is intended to be in contact with
articles that are being ironed.
[0021] Chamber 2 has a zone 200, shown most clearly in FIG. 2, into
which water drops are delivered from system 4. Zone 200, in which
steam is produced, is extended across soleplate 1 by a second zone
201 that is closed by ribs 202 and a screen 203. Screen 203 is an
element preferably made of an expanded metal, such as stainless
steel, optionally plated with a thin layer of gold. Screen 203 is
tightly clamped between closing plate 102 and the bottom of chamber
2 in order to assure an excellent electric contact between plate
102, screen 203 and heating body 100. An electric potential
difference is established between screen 203 and heating body 100
as a consequence of the different characteristics of the two
different metals employed for screen 203 and heating body 100.
[0022] Screen 203 is formed to have a mesh width between 0.3 and 3
millimeters and is made up of wires preferably having a polygonal
cross-section, which may for example be triangular, square, or
rectangular. Screen 203 is made of a metal material different from
that of heating body 100 and/or plate 102, and may for example be
made of stainless steel, optionally covered with a gold layer
having a thickness between 10 .mu.m and 100 .mu.m.
[0023] Advantageously, the bottom of chamber 2 is covered with an
anti-calefaction coating, i.e. a coating that prevents water
droplets dropped onto a hot plate from remaining in liquid form.
The steam produced in chamber 2 can escape through passages 206,
channels 204 and holes 207 toward steam delivery openings 205 that
are provide in liner 103 for delivery to an article being pressed,
either directly or via other distribution channels located the
soleplate. The steam delivery passages and channels and the steam
outlet openings in liner 103 can be formed according to principles
that are well known in the art.
[0024] When the pressing iron is at room temperature, only very
little SHMP is librated from silicone matrix 305, even if matrix
305 is wetted. When the iron is to be used, the user fills water
reservoir 3 via opening 302 and then moves cover 303 into the
closed position shown in FIG. 1. When the iron is heated, the
temperature in the reservoir is first raised to a moderate level
that is sufficient to strongly accelerate diffusion of SHMP into
the water, and vapor diffusing toward the SHMP grains, which are
very hydrophilic, causes the grains to be charged with water and to
swell, thereby breaking the silicone network. The SHMP diffusion
front progresses slowly into the matrix along the axis of tubular
element 304, i.e. perpendicular to the plane of FIG. 1, the
cross-section of element 304 being constant in this direction, and
the diffusion of SHMP is thus well controlled.
[0025] Preferably, the length and cross-section of tubular element
304 are selected to assure a continued diffusion of the
scale-preventing product for the useful life of the iron. In
another form of construction, tubular element 304 and its silicone
matrix 305 are replaceable.
[0026] During ironing, the user can activate a control element 40
to operate system 4, leading to the production of steam that will
be used in the ironing process. When control element, or button, 40
is depressed, water containing dissolved SHMP is allowed to flow in
the form of drops from reservoir 3 into chamber 2, where the drops
fall into zone 200. The water spreads out to a greater or lesser
extent across chamber 2, the extent depending on the flow rate, and
reaches zone 201. Vaporization of the water produces steam which
flows toward the article being ironed while passing through screen
203 and then into passages 206 and channels such as 204 and holes
207 in order to reach delivery of openings 205 of the
soleplate.
[0027] Any scale left by the vaporization of the water is in large
measure in powder form due the action of the SHMP and is evacuated
by being at least in part entrained by the steam.
[0028] Another part of the scale left by the water attaches to the
wall of chamber 2 in the form of a crumbly, or friable, layer,
which scale material subsequently detaches in the form of flakes
that are then retained by screen 203. A further part of the scale
comes to be deposited as a crust directly on screen 203.
Surprisingly, the flakes and the crust of scale disintegrate at the
level of the screen into a fine powder that is invisible to the
naked eye, this powder then being evacuated out of the iron through
the steam delivery openings. It is thought that the electric
potential differential present at the level of screen 203, of the
order 2-3 volts, provokes a transformation of the cohesion of the
scale crystals, this transformation possibly being completed by the
polygonal geometry of the cross-section of the wires of the screen.
Screen 203 then is able to prevent the passage of large particles
and retains them so that they can be transformed into fine powder.
According to other embodiments of the invention, the SHMP can be
replaced another hydrophilic phosphorous product.
[0029] As a result, the scale is evacuated regularly in an
invisible form and without inconveniencing the user. The useful
life of the iron is increased by the hydrophilic scale-preventing
product while, at the same time, this product does not create any
inconveniences, such as the appearance of stains on the articles
being ironed.
[0030] This application relates to subject matter disclosed in
German Application No. DE-100 14 815.8, filed Mar. 27, 2000, the
entirety of which is incorporated herein by reference.
[0031] The foregoing description of the specific embodiments will
so fully reveal the general nature of the invention that others
can, by applying current knowledge, readily modify and/or adapt for
various applications such specific embodiments without undue
experimentation and without departing from the generic concept,
and, therefore, such adaptations and modifications should and are
intended to be comprehended within the meaning and range of
equivalents of the disclosed embodiments. It is to be understood
that the phraseology or terminology employed herein is for the
purpose of description and not of limitation. The means, materials,
and steps for carrying out various disclosed functions may take a
variety of alternative forms without departing from the invention.
Thus the expressions "means to . . . " and "means for . . . ", or
any method step language, as may be found in the specification
above and/or in the claims below, followed by a functional
statement, are intended to define and cover whatever structural,
physical, chemical or electrical element or structure, or whatever
method step, which may now or in the future exist which carries out
the recited function, whether or not precisely equivalent to the
embodiment or embodiments disclosed in the specification above,
i.e., other means or steps for carrying out the same functions can
be used; and it is intended that such expressions be given their
broadest interpretation.
* * * * *