[001] The present disclosure, in general, relates to all types of household clothing iron
such as dry and steam iron and more particularly, to safety indication system for
household clothing iron. The safety indication system visually indicate the temperature
of the sole plate in order to avoid accidental touching by user when the sole plate is hot.
Further, the system acts as a secondary indicator to the thermostat to indicate the state of
the household clothing iron. Furthermore, the system alternatively provides a mechanism
to cut-off power supply to sole plate heating element when temperature of the sole plate
tantamount to operational mode selected.
BACKGROUND OF THE INVENTION
[002] Household clothing iron is an apparatus widely used in household to remove
wrinkles and creases from the garments. The operating temperature of household clothing
iron is generally in the range of 130oC to 230o C. It has become a general practice to check
the temperature of sole plate of the household clothing iron before using it on the garments
to save the garments from any type of damage due to high temperature. Further, user has
to left the household clothing iron in open to bring the temperature of the sole plate back
to normal and often user has to touch the sole plate physically to ensure that sole plate
temperature is back to normal so that the household clothing iron can be put back into
storage. Checking the sole plate temperature physically may cause burn injuries. Also a
recently switched off iron can be a hazard for other non-users like children who are not
aware that the sole plate is hot and might accidentally come in contact with it.
[003] Furthermore, in household clothing iron different temperature modes are provided
for different types of garments material such as, cotton, wool, nylon etc. While ironing
the garments of different types, the temperature modes are changed multiple time. User
has to keep in check the temperature of the sole plate with the temperature required for a
particular garment type. Presently available household clothing iron does not have any
3
indicating device which indicates if the temperature of the sole plate has reached the
temperature chosen by the user as per the type of garment. Lack of indication of this type
may lead to accidental damage to the garments.
[004] In presently available household clothing iron there is no secondary indicator
available for thermostat to determine if the sole plate has reached the temperature set by
the user.
[005] Presently available household clothing iron does not show the extent of hotness
of the sole plate. Further, presently available household clothing does not have the thermal
indicator which can confirm that the temperature has tantamount to operation mode
selected by the user and iron can now be used on a particular type of garment.
Furthermore, presently available household clothing iron does not have provision to
control the thermostat using a thermo-chromic part.
[006] Therefore, there is a need to develop a safety indication system for household
clothing iron which can obviate the drawbacks mentioned above.
OBJECT OF THE INVENTION
[007] It is therefore an object of the present invention, to solve the aforementioned and
other drawbacks existing in the existing household clothing iron.
[008] Another primary object of the present invention is to provide a safety indication
system for household clothing iron.
[009] Yet another objective of the present invention is to provide a safety indication
system for household clothing iron which can indicate the extent of hotness of the sole
plate to avoid touching of the hot sole plate.
[0010] Yet another object of the present invention is to provide a safety indication system
for household clothing iron to serve as an alternative mechanism to actuate the thermostat
4
to cut-off power supply to the sole plate heating element when sole plate temperature
tantamount to operational mode selected.
[0011] Yet another object of the present invention is to provide a safety indication system
for household clothing iron to serve as a secondary indicator to the thermostat by showing
the state of the iron sole plate.
[0012] Yet another object of the present invention is to provide a safety indication system
for household clothing iron to indicate the user that the sole plate temperature tantamount
to operational mode selected by the user to iron a particular type of garment.
[0013] Still yet another object of the present invention is to provide a safety indication
system for household clothing iron to eliminate the damage due to direct contact of
thermo-chromic paint with the heat from the sole plate.
SUMMARY OF THE INVENTION
[0014] One or more drawbacks of conventional safety indicator in housing clothing iron,
and additional advantages are provided through the safety indication system for
household clothing iron as claimed in the present disclosure. Additional features and
advantages are realized through the technicalities of the present disclosure. Other
embodiments and aspects of the disclosure are described in detail herein and are
considered to be a part of the claimed disclosure.
[0015] The present subject matter relates to a safety indicator system in household
clothing iron. The safety indicator system, according to first embodiment, comprises a
sole plate heating element, a thermostat and a thermo-chromic part. The sole plate heating
element is electrically connected with a power supply. The thermostat is electrically
connected in series with the sole plate heating element and the power supply, to cut-off
power supply to the sole plate heating element when temperature of the sole plate
tantamount to operational mode selected by the user. The thermo-chromic part which acts
as a thermo-chromic indicator is electrically connected in parallel with the sole plate
5
heating element and in series with the thermostat and the power supply to visually indicate
the temperature of the sole plate in order to avoid touching the hot sole plate and provide
an alternate mechanism to the thermostat to cut-off power supply to the sole plate heating
element when temperature of the sole plate tantamount to operational mode selected by
the user.
[0016] In an aspect, the thermo-chromic part comprises a wired layer of thermo-chromic
pigment sandwiched between two layers of transparent insulation for reversible color
change.
[0017] In an aspect, the wired layer of thermo-chromic pigment has multiple coatings of
different thermo-chromic pigments each coating being activated at different temperature
resulting in indication of operational mode of the household clothing iron.
[0018] In an aspect, the thermo-chromic pigment is adapted to absorb different intensities
of light at different temperature, reversibly.
[0019] In an aspect, the transparent insulation is chosen, such that, it does not interfere
with the visualization characteristics of the thermo-chromic pigments and allows cooling
of the pigment naturally once the clothing iron is switched off.
[0020] In an aspect, the thermo-chromic part has a thermocouple to measure temperature
and actuate the thermostat in accordance with the operational mode selected on the
household clothing iron.
[0021] In an aspect, the wire used in the thermo-chromic part is made of nichrome alloy.
[0022] In an aspect, temperature calibration is done between temperature of sole plate
heating element and the wire provided in the wired layer of thermo-chromic pigments.
[0023] In an aspect, thermal cut-off is provided for both the sole plate heating element
and the thermo-chromic part for safety purpose.
6
[0024] According to the second embodiment, the safety indicator system comprises a sole
plate heating element, a thermostat and a thermo-chromic part. The sole plate heating
element is electrically connected with a power supply. The thermostat is electrically
connected in series with the sole plate heating element and the power supply, to cut-off
power supply to the sole plate heating element when temperature of the sole plate
tantamount to operational mode selected by the user. The thermo-chromic part which acts
as a thermo-chromic indicator is electrically connected in series with the sole plate heating
element and in series with the thermostat and the power supply to visually indicate the
temperature of the sole plate in order to avoid touching the hot sole plate and provide an
alternate mechanism to the thermostat to cut-off power supply to the sole plate heating
element when temperature of the sole plate tantamount to operational mode selected by
the user.
[0025] In an aspect, either a shunt resistance or a capacitor is provided in parallel to the
wire in the wired thermo-chromic pigments to prevent burning out of the wire.
[0026] In an aspect, the thermo-chromic part comprises a wired layer of thermo-chromic
pigment sandwiched between two layers of transparent insulation for reversible color
change.
[0027] In an aspect, the wired layer of thermo-chromic pigment has multiple coatings of
different thermo-chromic pigments each coating being activated at different temperature
resulting in indication of operational mode of the household clothing iron.
[0028] In an aspect, the thermo-chromic pigment is adapted to absorb different intensities
of light at different temperature, reversibly.
[0029] In an aspect, the transparent insulation is chosen, such that, it does not interfere
with the visualization characteristics of the thermo-chromic pigments and allows cooling
of the pigment naturally once the clothing iron is switched off.
7
[0030] In an aspect, the thermo-chromic part has a thermocouple to measure temperature
and actuate the thermostat in accordance with the operational mode selected on the
household clothing iron.
[0031] In an aspect, the wire used in the thermo-chromic part is made of nichrome alloy.
[0032] In an aspect, temperature calibration is done between temperature of sole plate
heating element and the wire provided in the wired layer of thermo-chromic pigments.
[0033] In an aspect, thermal cut-off is provided for both the sole plate heating element
and the thermo-chromic part for safety purpose.
[0034] According to the third embodiment, the safety indicator system comprises a sole
plate heating element, a thermostat and a thermo-chromic part. The sole plate heating
element is electrically connected with a power supply. A layer of thermo-chromic paint
is applied near the sole plate on the PBT part of the iron. The thermostat is electrically
connected in series with the sole plate heating element and the power supply, to cut-off
power supply to the sole plate heating element when temperature of the sole plate
tantamount to operational mode selected by the user. The thermo-chromic part which acts
as a thermo-chromic indicator is electrically connected in parallel with the sole plate
heating element and in series with the thermostat and the power supply to visually indicate
the temperature of the sole plate in order to avoid touching the hot sole plate and provide
an alternate mechanism to the thermostat to cut-off power supply to the sole plate heating
element when temperature of the sole plate tantamount to operational mode selected by
the user.
[0035] According to the fourth embodiment, the safety indicator system comprises a sole
plate heating element, a thermostat and a thermo-chromic part. The sole plate heating
element is electrically connected with a power supply. A layer of thermo-chromic paint
is applied near the sole plate on the PBT part of the iron. The thermostat is electrically
connected in series with the sole plate heating element and the power supply, to cut-off
power supply to the sole plate heating element when temperature of the sole plate
8
tantamount to operational mode selected by the user. The thermo-chromic part which acts
as a thermo-chromic indicator is electrically connected in series with the sole plate heating
element and in series with the thermostat and the power supply to visually indicate the
temperature of the sole plate in order to avoid touching the hot sole plate and provide an
alternate mechanism to the thermostat to cut-off power supply to the sole plate heating
element when temperature of the sole plate tantamount to operational mode selected by
the user.
[0036] In order to further understand the characteristics and technical contents of the
present invention, a description relating thereto has been made with reference to the
accompanying drawings. However, the drawings are illustrative only but not used to limit
scope of the present subject matter.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0037] Further objects and advantages of this invention will be more apparent from the
description when read in conjunction with accompanying drawings of exemplary
embodiments of invention and wherein:
[0038] Figure 1 illustrates circuit diagram of the safety indication system according to
first embodiment of the present subject matter;
[0039] figure 2 illustrating the thermo-chromic part in accordance with one of the
embodiment of the present subject matter;
[0040] Figure 3 illustrates a safety indication system for household clothing iron
according to second embodiment of the present subject matter;
[0041] Figure 4 illustrating placement of thermo-chromic part in the household clothing
iron according to one of the embodiment of present subject matter; and
[0042] Figure 5 illustrates placement of thermo-chromic paint in the household clothing
iron according to third and fourth embodiment of the present subject matter.
9
DETAILED DESCRIPTION OF THE INVENTION
[0043] The present invention discloses a safety indication system 100 for household
clothing iron to visually indicate the temperature of sole plate in order to avoid touching
of hot sole plate and also to serve as an alternative mechanism to the thermostat to cutoff power supply to sole plate heating element 101 when temperature of sole plate
tantamount to operational mode selected by the user. Further, the safety indication system
100 also serves as a secondary indicator to the thermostat by showing the state of the iron
sole plate.
[0044] Referring to Figure 1 illustrating circuit diagram of the safety indication system
100 according to first embodiment of the present subject matter. The safety indication
system 100 for household clothing iron comprises a sole plate heating element 101, a
thermostat 102 and a thermo-chromic part 103. The sole plate heating element 101 is
electrically connected with a power supply 104. The sole plate heating element 101
converts electrical energy from the power supply 104 into heat which in turn raise the
temperature of the sole plate. The sole plate heating element 101 is made up of Nichrome.
[0045] The thermostat 102 is electrically connected in series with the sole plate heating
element 101 and the power supply 104. The thermostat 102 cut-off the power supply 104
to the sole plate heating element 101 when temperature of the sole plate tantamount to
the operational mode selected by the user. The thermostat 102 keep in check the
maximum temperature of the sole plate at any instant of its use. In the household clothing
iron, provisions are provided to select the operational mode of the iron. These operational
modes are divided into temperature ranges suitable for a particular type of clothing
material. For example, cotton can withstand temperature up to 204oC, so while ironing
any cotton garment user can select operational mode below this temperature. Similarly,
this can be done for linen (230o C), wool (148oC), silk (148oC) and Nylon (135o
C). The
thermostat 102 provided in the household clothing iron cut-off the power supply 104 to
the sole plate heating element 101 to restrict the temperature of the sole plate within this
range of temperature. In this way, thermostat 102 save garments from accidental burns.
10
Usually, a bi-metallic strip is used as a thermostat 102 in the household clothing iron near
the sole plate heating element 101 and gets actuated by the heat from the sole plate
element 101. In an aspect, instead of a bimetallic strip, a thermostat 102 with a
thermocouple (not shown) located at the thermo-chromic part 103 is used to maintain the
temperature of the sole plate. Thermocouple converts the heat generated in to electrical
signals and based on the signal received the thermostat 102 is actuated. Thermostat 102
is a device used to control and measure temperature. It includes a thermocouple to
measure the temperature and a control circuit to actuate accordingly.
[0046] Referring to figure 2 illustrating the thermo-chromic part 103 in accordance with
one of the embodiment of the present subject matter. The thermo-chromic part 103 is used
to indicate the extent of hotness of the sole plate. In the first embodiment, the thermochromic part 103 is used as a thermo-chromic indicator to visually indicate the extent of
hotness of the sole plate. The thermo-chromic part 103 comprises a wired layer of thermochromic pigments 201 sandwiched between two layers of transparent insulation 202a,
202b. The thermo-chromic pigments 201 are heat sensitive pigments which transform its
color when exposed to a certain temperature.
[0047] In the first embodiment, a reversible kind of thermo-chromic pigments 201 is used
which can transform its color back and forth to provide an indication of the current
temperature.
[0048] The wired layer of thermo-chromic pigments 201 has multiple coating of different
thermo-chromic pigments. Each of these thermo-chromic pigments are configured to be
activated at different temperatures. Preferably, each of the multiple coatings of the
different thermo-chromic pigments 201 correspond to different operational modes
provided in the housing iron. These multiple coatings of thermo-chromic pigments 201
absorb different intensities of light at different temperatures to facilitate clear distinction
in shade of color while transitioning from one operational mode to the other. In this way,
the user can easily notice the transition between operational modes.
11
[0049] The transparent insulation 202a, 202b is chosen to provide insulation to the wired
layer of thermo-chromic pigments 201. The transparent insulation 202a, 202b does not
interfere with the visualization characteristics of the thermo-chromic pigments 201. This
ensures indication of temperature is conveyed to the user without having any possibility
of inaccuracy. Further, the transparent insulation 202a, 202b used, allows cooling of the
pigment naturally once the clothing iron is switched off.
[0050] The wire provided in the wired layer of thermo-chromic pigments 201 are
electrically connected in parallel to the sole plate heating element 101 and in series with
the power supply 104 and the thermostat 102. The value of the resistance of the wire
provided in the wired layer of thermo-chromic pigments 201 depends on various
parameters like the material selected, dimensional constraints, operating temperatures,
form, calibration temperature, etc. Due to its resistance, the wire in the wired layer of
thermo-chromic pigments 201 generates heat. The heat generated activates the thermochromic pigments 201. In general, the operating temperature range of the thermo-chromic
part 103 is between 30o C to 80o C and the operating temperature range of the sole plate
heating element is 130oC to 230o
C. Since the thermo-chromic part 103 damages at high
temperatures, temperature calibration is done between temperature of sole plate heating
element 101 and the wire provided in the wired layer of thermo-chromic pigments 201.
This temperature calibration is done over different modes of operation of the household
clothing iron, so that, the thermo-chromic part 103 indicate the extent of hotness over the
entire operating temperature range of the sole plate heating element 101.
[0051] A thermocouple is provided in the thermo-chromic part 103 to measure the
temperature. The thermocouple measures the temperature of the thermo-chromic part
and actuate the thermostat 102 when the temperature of the thermo-chromic part 103
tantamount to operational mode selected by the user. For safety purposes, thermal cut-off
is provided for both sole plate heating element 101 and the thermo-chromic part 103 for
safety purpose.
12
[0052] Referring to Figure 3 illustrating a safety indication system 300 for household
clothing iron according to second embodiment of the present subject matter. The safety
indication system 300 for household clothing iron comprises a sole plate heating element
301, a thermostat 302 and a thermo-chromic part 303 all connected in series. The sole
plate heating element 301 is electrically connected with a power supply 304. The sole
plate heating element 301 converts electrical energy from the power supply 304 into heat
which in turn raise the temperature of the sole plate. The sole plate heating element 301
is made up of Nichrome.
[0053] The thermostat 302 is electrically connected in series with the sole plate heating
element 301 and the power supply 304. The thermostat 302 cut-off the power supply 304
to the sole plate heating element 301 when temperature of the sole plate tantamount to
the operational mode selected by the user. The thermostat 302 keep in check the
maximum temperature of the sole plate at any instant of its use. In the household clothing
iron, provisions are provided to select the operational mode of the iron. These operational
modes are divided into temperature ranges suitable for a particular type of clothing
material. For example, cotton can withstand temperature up to 204o C, so while ironing
any cotton garment user can select operational mode below this temperature. Similarly,
this can be done for linen (230o C), wool (148o
C), silk (148oC) and nylon (135oC). The
thermostat 302 provided in the household clothing iron cut-off the power supply to the
sole plate heating element 301 to restrict the temperature of the sole plate within this range
of temperature. In this way, thermostat 302 save garments from accidental burns. Usually,
a bi-metallic strip is used as a thermostat 302 in the household clothing iron near the sole
plate heating element 301 and gets actuated by the heat from the sole plate element 301.
[0054] In an aspect, instead of a bimetallic strip, a thermostat 302 with a thermocouple
located at the thermo-chromic part 303 is used to maintain the temperature of the sole
plate. Thermocouple converts the heat generated in to electrical signals and based on the
signal received the thermostat 302 is actuated. Thermostat 302 is a device used to control
13
and measure temperature. It includes a thermocouple to measure the temperature and a
control circuit to actuate accordingly.
[0055] The thermo-chromic part 303 in the second embodiment is identical to the thermochromic part 303 of the first embodiment. The placement of the thermo-chromic part 303
in second embodiment is different that the first embodiment. Instead of providing the
thermo-chromic part 303 in parallel with the power supply and the sole plate heating
element 301 like in first embodiment, the thermo-chromic part 303 is provided in series
with the power supply 304 and the sole plate heating element 301.
[0056] The wire provided in the wired layer of thermo-chromic pigments 201 are
electrically connected in series to the sole plate heating element 301 and in series with
the power supply 304 and the thermostat 302. The value of the resistance of the wire
provided in the wired layer of thermo-chromic pigments 201 depends on various
parameters like the material selected, dimensional constraints, operating temperatures,
form, calibration temperature, etc. Due to its resistance, the wire in the wired layer of
thermo-chromic pigments 201 generates heat. The heat generated activates the thermochromic pigments 201. In general, the operating temperature range of the thermo-chromic
part 303 is between 30o C to 80o C and the operating temperature range of the sole plate
heating element is 130OC to 230oC. Since the thermo-chromic part 303 damages at high
temperatures, temperature calibration is done between temperature of sole plate heating
element 301 and the wire provided in the wired layer of thermo-chromic pigments 201.
This temperature calibration is done over different modes of operation of the household
clothing iron, so that, the thermo-chromic part 303 indicates the extent of hotness over
the entire operating temperature range of the sole plate heating element 301.
[0057] A thermocouple is provided in the thermo-chromic part 303 to measure the
temperature. The thermocouple is electrically connected in series with the thermostat 302
and serves as a secondary indicator to the thermostat 302. The thermocouple measures
the temperature of the thermo-chromic part 303 and actuate the thermostat 302 when the
temperature of the thermo-chromic part 303 tantamount to operational mode selected by
14
the user. For safety purposes, thermal cut-off is provided for both sole plate heating
element 301 and the thermo-chromic part 303 for safety purpose.
[0058] Referring to Figure 4 illustrating placement of thermo-chromic part 103, 303 in
the household clothing iron according to one of the embodiment of present subject matter.
Preferably, the thermo-chromic part 103, 303 is placed within the PBT part on either side
of the household clothing iron. The thermo-chromic part 103, 303 is provided above the
sole plate with a gap in between.
[0059] Referring to figure 5 illustrating placement of thermo-chromic paint in the
household clothing iron according to third and fourth embodiment of the present subject
matter. In the third embodiment an additional layer of thermo-chromic paint is applied
near the sole plate on the PBT part of the household clothing iron apart from the features
of the first embodiment.
[0060] According to the forth embodiment of the present subject matter, an additional
layer of thermo-chromic paint is applied near the sole plate on the PBT part of the
household clothing iron apart from the features of the second embodiment.
WORKING OF THE FIRST EMBODIMENT
[0061] In the first embodiment, the power supply 104 is electrically connected with the
thermostat 102, the sole plate heating element 101 and the thermo-chromic part 103 in
series. The sole plate heating element 101 and the thermo-chromic part 103 are connected
in parallel with each other. The sole plate heating element 101 heat up the sole plate by
converting electric energy from the power source to heat. The thermocouple provided in
the thermo-chromic part 103 measures the temperature and cut-off power supply to the
sole plate heating element 101, using thermostat 102, when the temperature of the sole
plate tantamount to operational mode selected by the user. Meanwhile, as the temperature
start increasing the thermo-chromic part 103 starting transitioning from one shade to
another. There are indications provided on the household clothing iron about the color
and what operational mode it represents. As soon as the thermo-chromic part 103 transit
15
from one color to other, the user knows about the range of temperature at which the sole
plate is at that moment. In this way user is always aware of the extent of hotness of the
sole plate of the housing clothing iron. After use, when the power supply is off, the color
of the thermo-chromic part 103 transit to normal as the temperature of the sole plate
lowers to the room temperature.
[0062] In the first embodiment, the thermo-chromic part 103 is electrically connected in
parallel to the sole plate heating element 101. Due to this parallel connection, if there is
any malfunction in the system 100, the function of the household clothing iron is not
affected. Also the current in the thermo-chromic wire is comparatively low and reduce
chances of burning out of wire in case of high current flow.
[0063] In the second embodiment, the power supply 304 is electrically connected with
the thermostat 302, the sole plate heating element 301 and the thermo-chromic part 303
in series. The sole plate heating element 301 and the thermo-chromic part 303 are
connected in series with each other. The sole plate heating element 301 heat up the sole
plate by converting electric energy from the power source 304 to heat. The thermocouple
provided in the thermo-chromic part 303 measures the temperature and cut-off power
supply to the sole plate heating element 301, using thermostat 302, when the temperature
of the sole plate tantamount to operational mode selected by the user. Meanwhile, as the
temperature start increasing the thermo-chromic part 303 starting transitioning from one
shade to another. There are indications provided on the household clothing iron about the
color and what operational mode it represents. As soon as the thermo-chromic part 303
transit from one color to other, the user knows about the range of temperature at which
the sole plate is at that moment. In this way user is always aware of the extent of hotness
of the sole plate of the housing clothing iron. After use, when the power supply is off, the
color of the thermo-chromic part 303 transit to normal as the temperature of the sole plate
lowers to the room temperature.
[0064] In the second embodiment, the thermo-chromic part 303 is electrically connected
in series to the sole plate heating element 301. Due to this series connection, if there is
16
any malfunction in the system 303, the function of the household clothing iron is
completely shut.in this way the system 303 save the user from accidental burns.
[0065] In the third embodiment, an additional layer of thermo-chromic paint 501 is
applied near the sole plate on the PBT part of the household clothing iron. This thermochromic paint 501 layer changes its color in accordance with heat emitted from the sole
plate directly. Other functioning of the third embodiment works similar to the first
embodiment.
[0066] In the fourth embodiment, an additional layer of thermo-chromic paint 501 is
applied near the sole plate on the PBT part of the household clothing iron. This thermochromic paint 501 layer changes its color in accordance with heat emitted from the sole
plate directly. Other functioning of the fourth embodiment works similar to the second
embodiment.
[0067] The advantages of present safety indication system 100, 300 are manifold as
provided below:
 The safety indication system 100, 300 provides visual indication of extent
of hotness of the sole plate of the household clothing iron. This eliminates
the accidental touching of hot sole plate of the housing clothing iron by
the user.
 The safety indication system 100, 300provides an alternative mechanism
to actuate the thermostat 102, 302 to cut-off power supply 104, 304 to the
sole plate heating element101, 301 when sole plate temperature
tantamount to operational mode selected.
 The safety indication system 100, 300 serves as a secondary indicator to
the thermostat 102, 302 by showing the state of the iron sole plate.
17
 The safety indication system 100, 300 indicates the user that the sole plate
temperature tantamount to operational mode selected by the user to iron a
particular type of garment.
[0068] It will be understood by those within the art that, in general, terms used herein,
and especially in the appended claims (e.g., bodies of the appended claims) are generally
intended as “open” terms (e.g., the term “including” should be interpreted as “including
but not limited to,” the term “having” should be interpreted as “having at least,” the term
“includes” should be interpreted as “includes but is not limited to,” etc.). It will be further
understood by those within the art that if a specific number of an introduced claim
recitation is intended, such an intent will be explicitly recited in the claim, and in the
absence of such recitation no such intent is present. For example, as an aid to
understanding, the following appended claims may contain usage of the introductory
phrases “at least one” and “one or more” to introduce claim recitations. However, the use
of such phrases should not be construed to imply that the introduction of a claim recitation
by the indefinite articles “a” or “an” limits any particular claim containing such
introduced claim recitation to inventions containing only one such recitation, even when
the same claim includes the introductory phrases “one or more” or “at least one” and
indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted
to mean “at least one” or “one or more”); the same holds true for the use of definite articles
used to introduce claim recitations. In addition, even if a specific number of an introduced
claim recitation is explicitly recited, those skilled in the art will recognize that such
recitation should typically be interpreted to mean at least the recited number (e.g., the
bare recitation of “two recitations,” without other modifiers, typically means at least two
recitations, or two or more recitations). Furthermore, in those instances where a
convention analogous to “at least one of A, B, and C, etc.” is used, in general such a
construction is intended in the sense one having skill in the art would understand the
convention (e.g., “a system having at least one of A, B, and C” would include but not be
limited to systems that have A alone, B alone, C alone, A and B together, A and C
together, B and C together, and/or A, B, and C together, etc.). In those instances where a
18
convention analogous to “at least one of A, B, or C, etc.” is used, in general such a
construction is intended in the sense one having skill in the art would understand the
convention (e.g., “a system having at least one of A, B, or C” would include but not be
limited to systems that have A alone, B alone, C alone, A and B together, A and C
together, B and C together, and/or A, B, and C together, etc.). It will be further understood
by those within the art that virtually any disjunctive word and/or phrase presenting two
or more alternative terms, whether in the description, claims, or drawings, should be
understood to contemplate the possibilities of including one of the terms, either of the
terms, or both terms. For example, the phrase “A or B” will be understood to include the
possibilities of “A” or “B” or “A and B.”
[0069] It will be further appreciated that functions or structures of a plurality of
components or steps may be combined into a single component or step, or the functions
or structures of one-step or component may be split among plural steps or components.
The present invention contemplates all of these combinations. Unless stated otherwise,
dimensions and geometries of the various structures depicted herein are not intended to
be restrictive of the invention, and other dimensions or geometries are possible. In
addition, while a feature of the present invention may have been described in the context
of only one of the illustrated embodiments, such feature may be combined with one or
more other features of other embodiments, for any given application. It will also be
appreciated from the above that the fabrication of the unique structures herein and the
operation thereof also constitute methods in accordance with the present invention. The
present invention also encompasses intermediate and end products resulting from the
practice of the methods herein. The use of “comprising” or “including” also contemplates
embodiments that “consist essentially of” or “consist of” the recited feature.

We Claim:

1. A safety indication system (100) for household clothing iron, the safety indication
system (100) comprises:
a sole plate heating element (101) electrically connected with a power
supply (104);
a thermostat (102), electrically connected in series with the sole plate
heating element (101) and the power supply (104), to cut-off power supply to the
sole plate heating element (101) when temperature of the sole plate tantamount to
operational mode selected by the user;
a thermo-chromic part (103), acting as a thermo-chromic indicator,
electrically connected in parallel with the sole plate heating element (101) and in
series with the thermostat (102) and the power supply (104) to visually indicate
the temperature of the sole plate in order to avoid touching the hot sole plate and
as an additional mechanism to the thermostat (102) to cut-off power supply to the
sole plate heating element (101) when temperature of the sole plate tantamount to
operational mode selected by the user.
2. The safety indication system (100) as claimed in claim 1, wherein the thermochromic part (103) comprises a wired layer of thermo-chromic pigments (201)
sandwiched between two layers of transparent insulation (202a, 202b) for
reversible colour change.
3. The safety indication system (100) as claimed in claim 2, wherein the wired layer
of thermo-chromic pigments (201) has multiple coatings of different thermochromic pigments each coating being activated at different temperature resulting
in indication of operational mode of the household clothing iron.
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4. The safety indication system (100) as claimed in claim 2 and 3, wherein the
thermo-chromic pigment is adapted to absorb different intensities of light at
different temperature, reversibly.
5. The safety indication system (100) as claimed in claim 2, wherein the transparent
insulation (202a, 202b) is chosen, such that, it does not interfere with the
visualization characteristics of the thermo-chromic pigments 201 and allows
cooling of the pigment naturally once the clothing iron is switched off.
6. The safety indication system (100) as claimed in claim 2, wherein the thermochromic part (103) has a thermocouple to measure temperature and actuate the
thermostat (102) in accordance with the operational mode selected on the
household clothing iron.
7. The safety indication system (100) as claimed in claims 2, wherein the wire used
in the thermo-chromic part (103) is made of nichrome alloy.
8. The safety indication system (100) as claimed in claim 1, wherein temperature
calibration is done between temperature of sole plate heating element (101) and
the wire provided in the wired layer of thermo-chromic pigments (201).
9. The safety indication system (100) as claimed in claim 1, wherein thermal cut-off
is provided for both the sole plate heating element (101) and the thermo-chromic
part (103) for safety purpose.
10. A safety indication system (300) for household clothing iron, the safety indication
system (300) comprises:
a sole plate heating element (301) electrically connected with a power
supply (304);
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a thermostat (302) electrically connected between the sole plate heating
element (301) and the power supply (304) to cut-off power supply (304) to the
sole plate heating element (301) when desired temperature is attained;
a thermo-chromic part (303), acting as a thermo-chromic indicator,
electrically connected in series with the sole plate heating element (301), power
supply (304) and the thermostat (302) to visually indicate the temperature of the
sole plate and provide an alternative mechanism to the thermostat (302) to cut-off
power supply (304) to the sole plate heating element (301).
11. The safety indication system (300) as claimed in claim 10, wherein either a shunt
resistance or a capacitor is provided in parallel to the wire in the wired thermochromic pigments (201) to prevent burning out of the wire.
12. The safety indication system (300) as claimed in claim 10, wherein the thermochromic part (303) comprises a wired layer of thermo-chromic pigments (201)
sandwiched between two layers of transparent insulation (202a, 202b) for
reversible colour change.
13. The safety indication system (300) as claimed in claim 12, wherein the wired layer
of thermo-chromic pigments 201 has multiple coatings of different thermochromic pigments each coating being activated at different temperature resulting
in indication of operational mode of the household clothing iron.
14. The safety indication system (300) as claimed in claim 12 and 13, wherein the
thermo-chromic pigments (201) is adapted to absorb different intensities of light
at different temperature, reversibly.
15. The safety indication system (300) as claimed in claim 12, wherein the transparent
insulation (202a, 202b) is chosen, such that, it does not interfere with the
visualization characteristics of the thermo-chromic pigments (201) and allows
cooling of the pigment naturally once the clothing iron is switched off.
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16. The safety indication system (300) as claimed in claim 12, wherein the thermochromic part (303) has a thermocouple to measure temperature and actuate the
thermostat (302) in accordance with the operational mode selected on the
household clothing iron.
17. The safety indication system (300) as claimed in claims 12, wherein the wire used
in the thermo-chromic part (303) is made of nichrome alloy.
18. The safety indication system (300) as claimed in claim 10 and 12, wherein
temperature calibration is done between temperature of sole plate heating element
(301) and the wire provided in the wired layer of thermo-chromic pigments (201).
19. The safety indication system (300) as claimed in claim 10, wherein thermal cutoff is provided for both the sole plate heating element (301) and the thermochromic part (303) for safety purpose.
20. A safety indication system for household clothing iron, the safety indication
system comprises:
a sole plate covered in thermo-chromic heating element electrically
connected with a power supply;
a layer of thermo-chromic paint (501) applied near the sole plate on the
PBT part of main body to indicate change in temperature of the sole plate;
a thermostat, electrically connected in series with the sole plate heating
element and the power supply, to cut-off power supply to the sole plate heating
element when temperature of the sole plate tantamount to operational mode
selected by the user;
a thermo-chromic part, acting as a thermo-chromic indicator, electrically
connected in parallel with the sole plate heating element and in series with the
thermostat and the power supply to visually indicate the temperature of the sole
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plate in order to avoid touching the hot sole plate and serve as a secondary
indicator to the thermostat to cut-off power supply to the sole plate heating
element when temperature of the sole plate tantamount to operational mode
selected by the user.
21. A safety indication system for household clothing iron, the safety indication
system comprises:
a sole plate covered in thermo-chromic heating element electrically
connected with a power supply;
a layer of thermo-chromic paint (501) applied near the sole plate on
the PBT part of main body to indicate change in temperature of the sole plate;
a thermostat, electrically connected in series with the sole plate heating
element and the power supply, to cut-off power supply to the sole plate heating
element when temperature of the sole plate tantamount to operational mode
selected by the user;
a thermo-chromic part, acting as a thermo-chromic indicator,
electrically connected in series with the sole plate heating element and in
series with the thermostat and the power supply to visually indicate the
temperature of the sole plate in order to avoid touching the hot sole plate and
serve as a secondary indicator to the thermostat to cut-off power supply to the
sole plate heating element when temperature of the sole plate tantamount to
operational mode selected by the user.