FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
An electric iron with improved safety features
APPLICANT
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400 030,
Maharashtra, India, an Indian Company
INVENTOR
Khedkar Parag Prabhakar of S3 Division, Switchgear Complex, Crompton Greaves Ltd, Ambad,
Nashik, Maharashtra, India, an Indian National
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to
be performed:

FTELD OF THE INVENTION
[001] The present invention relates generally to electric irons and more particularly to,
safety devices for irons to prevent energy waste and unsafe conditions.
DESCRIPTION OF THE BACKGROUND ART
[002J Conventional cloth iron includes a handle placed over a heating sole plate. The
sole plate is rolled over the fabric to remove wrinkles. To get effective results, the sole plate of an iron must be heated to a predetermined temperature. The selection of temperature is very critical depending on the type of fabrics used. In case of any negligence, it leads to burning of the fabric or ironing board or even igniting a fire from an electric iron. With the advent of technology, improved irons are also available with auto cut-off sensor if the temperature or heating of the iron crosses the predetermined value. In case the operator leaves the iron unattended for some time, it gets auto cut-off after a specified temperature and when it goes down it again starts drawing current and gets heated. However, this process leads to wastage of energy.
[003] The sole plate of a typical iron usually becomes very hot. Thus, there is a danger
that leaving an iron unattended can result in fire or serious damage to the clothing or ironing board. The danger is greatest when the user leaves the iron on and unattended for a long period of time. Thus, there is a need to provide an improved iron that overcomes at least some of these disadvantages.
SUMMARY OF THE INVENTION
[004] Accordingly disclosed herein is an electric iron having a safety device for
automatically interrupting supply of electric current to a heating resistor of an iron at the end of a predetermined non-use time interval of the iron, the iron including a housing, a sensing means disposable within the housing and including a transmitter and a receiver oppositely positioned to

each other, the transmitter and the receiver disposed along an axis perpendicular to forward-reverse motion of the iron, the sensing means capable of generating a first signal in response to electrical communication between the receiver and the transmitter during non-usage of the iron when disposed in a horizontal position, the sensing means capable of generating a second signal in response to interruption of electrical communication during non-usage of the iron when disposed in a vertical position, a pivotally supported pendulum having an opening and capable of being displaced under gravity between the transmitter and the receiver, the pendulum positioned in a first stable position during non-usage of the iron in the horizontal position and allowing electrical communication between the receiver and the transmitter through the opening, the pendulum displaceable to a second stable position during non-usage time in the vertical position and allowing a portion of the pendulum adjacent to the opening to interrupt electrical communication between the receiver and the transmitter, and a controller electrically couplable between the sensing means and a power supply, the controller capable of triggering the power supply in an off-condition when the controller receives the first and the second signals for the predetermined non-usage time interval.
[005] In some embodiments, both of the transmitter and the receiver are connected to.
the controller through a corresponding electrical connection, and wherein the receiver transmits the first and the second signals to the controller.
[006] In some embodiments, the first and the second signals corresponds to the
horizontal and the vertical positions of the iron, respectively, and wherein the first and second signals has a value of 0V and 5V, respectively.
[007] In some embodiments, the controller comprises of a timer operably connected
with the controller and the receiver, and wherein the timer is pre-programmed to transmit appropriate power-off signals to the controller when the timer receives the first signal for the% predetermined non-usage time interval.

[008] In some embodiments, a plurality of pins is disposed in spaced apart relationship
within a sole plate of iron, each of the pins are positioned between a corresponding solenoid coil electrically connected with the power supply, and wherein each of the pins protrude outside an outer surface of the sole plate when the power supply is in the off-condition and retract inwardly within the sole plate when the power supply is in an off-condition.
[009] It is to be understood that both the foregoing general description and the
following detailed description of the present embodiments of the invention are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operation of the invention.
A BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above-mentioned and other features and advantages of the various
embodiments of the invention, and the manner of attaining them, will become more apparent and will be better understood by reference to the accompanying drawings, wherein:
[0011] FIG. 1 is a perspective view of an iron connected to a control box and a power
supply according to an embodiment of the present invention;
[0012] FIG. 2 is a perspective view of a sensing device oriented within the iron of FIG.
Iwhen the iron is disposed in a horizontal position according to an embodiment of the present invention;
[0013] FIG. 3 is a perspective view of a sensing device of FIG. 2 oriented within the iron
when the iron is disposed in a vertical position;

[0014] . FIG. 4 is front elevational view of the iron having a retractable pin assembly
disposed within the iron according to an embodiment of the present invention; and
(0015] FIG. 5 is a zoomed-in view of the retractable pin assembly of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] FIG. 1 illustrates a perspective view of an iron 100 that is connected to a control
box 102 according to an embodiment of the present invention. The control box 102, amongst other components, includes a controller (not shown) and is further connected to a power supply wire 104 having a plug-in device 106 that may be connected to a power supply. The iron 100 is connected to the control box 102 by two wires as shown in FIG. 1. The thick wire 108 is primarily used for carrying the electric current received from the power supply to the resistor (not shown) that is embedded within a sole plate 110 of the iron 100. A thin wire 112 acts as an electrical interface between a safety device (FIG. 2) disposed within the iron 100 and the controller so that the safety device and the controller can interact as and when desired. Preferably, the iron 100 is a flat bed iron and as well known in the art, may be disposed in standstill orientation in both of the horizontal and vertical positions, respectively, depending on the use.
[0017] FIG. 1 also shows the iron 100 to have a housing 114 and a triangular shaped
cover 116 disposed at a rear end 118 thereof. FIG. 2 shows the iron 100 to be disposed in its horizontal position and includes the safety device disposed within the housing 114. Preferably, the safety device includes a sensing means that comprises of a transmitter 120 and a receiver 122 oppositely positioned to each other. As noted with respect to FIG. 2, both the transmitter 120 and the receiver 122 are disposed along an axis perpendicular to forward-reverse motion of the iron 100. Preferably, the transmitter 120 is a light emitting diode and the receiver 122 is a photodetector however various other similar sensing means may also be used within the iron 100

and considered to be within the scope of the present invention. Preferably, both the transmitter 120 and the receiver 122 do not have a common connection and the receiver 122 is connected to the controller within the control box 102. Thus, on behalf of the sensing means the receiver 122 sends the appropriate signals to the controller. Preferably, as seen in FIG. 1, both the transmitter 120 and the receiver 122 are mounted on a common base 124. Light from the transmitter 120 can be impinged on the photo detector, which is capable of converting light into either current or voltage, depending upon the mode of operation. Thus, when an electrical signal is applied to the input of the transmitter 120, the transmitter 120 illuminates and as when the receiver 122 receives the light it produces a corresponding electrical signal in its output circuit, which in turn is transmitted to the controller via thin wire 112.
[0018] Further, as seen in FIG. 2, a pendulum 126 is supported over a pair of parallel
frames 128 and suspended in between the transmitter 120 and the receiver 122. The parallel frames 128 are mounted on the base 124 adjacent to the transmitter 120 and the receiver 122 and are joined together at their upper ends via a rod 130. To this rod 130 the pendulum 126 is pivotally attached and suspended between the transmitter 120 and the receiver 122 in such a manner that a bottom portion of the pendulum 126 lays therebetween. The pendulum 126 also has an opening 132 formed near its bottom portion and subjected to displacement under the influence of gravity. The pendulum 126 is capable of swinging between the exposed area formed within the transmitter 120 and the receiver 122. However, when the iron 100 is disposed in the horizontal position and iron 100 is kept in non-use condition, the pendulum 126 remains in a first stable position 134 (See FIG. 2). During the first stable position 134, the opening 132 of the pendulum 126 is aligned with the transmitter 120 and the receiver 122 so as to allow light from the transmitter 120 to be received by the receiver 122. Whenever, the receiver 122 is illuminated, an electrical connection is established between the receiver 122 and the transmitter 120 and as a result of that a first signal is generated, which is transmitted to the controller.

[0019] However, whenever the light is interrupted, the electrical connection is disrupted
and as a result, the receiver 122 generates a second signal. This, interruption of light also occurs when the iron 100 is disposed in vertical position in the non-use condition This happens because the pendulum 126 is so designed that when the iron 100 is disposed in the vertical position, the pendulum 126 is positioned in a second stable position 136 (FIG. 3). In the second stable position 136, the pendulum 126 is slightly inclined in a manner that the bottom portion of the pendulum 126 does not falls outside the area defined by the transmitter 120 and the receiver 122. The falling of the pendulum 126 is prevented by the triangular cover positioned at the rear end 118 of the iron 100. In the second stable position 136, a portion of the pendulum 126 adjacent to the opening 132 comes in the way of light and as a result of that light is interrupted. Preferably, the first and second signal has a value of 0V and 5V, respectively. However, in other embodiments, other values from the receiver 122 may also be chosen and considered to be within the scope of the present invention. The first signal and the second signal received by the controller correspond to the horizontal and the vertical positions of the iron 100, respectively.
[0020] The controller, as can be seen in FIG. 1, comprises of a timer (not shown)
operably connected with the controller and the receiver 122 of the sensing means. The timer is pre-programmed to transmit appropriate power-off signals to the controller. The timer receives the first signal (0V) and the second signal (5V) from the receiver 122. The timer is preprogrammed in such a manner that when the first signal is received for a predetermined non-usage time interval, the controller switches off the power supply to prevent any further heating of the resistor coil. According to one embodiment of the present invention, the predetermined non-usage time interval in the horizontal position of the iron 100 is chosen to be 5 seconds however other non-usage time intervals may also be chosen and considered to be within the scope of the present invention. This prevents for example burning of clothes if the user accidently leaves the iron 100 in on condition during ironing of clothes. Thus, if the iron 100 is in horizontal position

and left unused, then the controller waits for 5 seconds and then switches off the supply to Iron 100. Similarly, the timer is also pre-programmed in such a manner that when the second signal (5V) is received for a predetermined non-usage time interval, the controller switches off the power supply to prevent any further heating of the resistor coil. According to one embodiment of the present invention, the predetermined non-usage time interval in the vertical position of the iron 100 is chosen to be 20 seconds however other non-usage time intervals may also be chosen and considered to be within the scope of the present invention. Thus, if the iron 100 is in the vertical position, the controller waits for 20 seconds and switches off the supply to the Iron 100. A relay device (not shown) is preferably used and operably connected with the controller to switch off- and on the power supply.
[0021] However, if the iron 100 changes its position or moves, the movement of
pendulum 126 interrupts the light producing some signal (the sensor voltage changes from its original level, i.e. 0 to 5V or 5 to 0V). This change in signal resets the controller timers to zero. After every reset it waits for another signal within 5 seconds, in the absence of such signal it switches off the supply.
[0022] FIGS. 4 and 5 show another embodiment of the present invention. The iron 100
includes a plurality of pins 138 disposed within the sole plate 11 Oof the iron 100. The plurality of pins 138 can project out vertically so as to lift the iron 100 upwardly from the surface on which it is positioned. One or more solenoid 140 can be provided to act against a spring 142 to retract the pins 138. When the supply can be put on the solenoids 140 can act against the spring 142 and retract the pins 138, making the sole plate 110 of the iron 100 touching the cloth. When the iron 100 is left unattended, the controller can also switch off the supply to the solenoid 140 along with the heating element of the iron 100. This ensures that the spring 142 can make the pins 138 extend out lifting the Iron 100 away from the cloth.

[0023] If the iron 100 is already in a hot condition even though the power can be
switched off by the controller, the heat available already in the Iron 100 can still spoil/burn the cloth. The purpose of these pins 138 is to lift the iron 100 away from the cloth to protect the cloth burning further, when the iron 100 is left unattended in a hot condition. These pins 138 can have springs 142 attached to it in such a way that the pins 138 can always protrude out and keep the Iron 100 away from the cloth.
[0024] It will be apparent to those skilled in the art that various modifications and
variations can be made to the present invention without departing from the spirit and scope of the invention. Thus it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

We Claim:
1. An electric iron having a safety device for automatically interrupting supply of electric current to a heating resistor of an iron at the end of a predetermined non-use time interval of the iron, the iron comprising:
a housing;
a sensing means disposable within the housing and including a transmitter and a receiver oppositely positioned to each other, the transmitter and the receiver disposed along an axis perpendicular to forward-reverse motion of the iron, the sensing means capable of generating a first signal in response to electrical communication between the receiver and the transmitter during non-usage of the iron when disposed in a horizontal position, the sensing means capable of generating a second signal in response to interruption of electrical communication during non-usage of the iron when disposed in a vertical position;
a pivotally supported pendulum having an opening and capable of being displaced under gravity between the transmitter and the receiver, the pendulum positioned in a first stable position during non-usage of the iron in the horizontal position and allowing electrical communication between the receiver and the transmitter through the opening, the pendulum displaceable to a second stable position during non-usage time in the vertical position and allowing a portion of the pendulum adjacent to the opening to interrupt electrical communication between the receiver and the transmitter; and
a controller electrically couplable between the sensing means and a power supply, the controller capable of triggering the power supply in an off-condition when the controller receives the first and the second signals for the predetermined non-usage time interval.

2. The electric iron according to claim 1, wherein both of the transmitter and the receiver are connected to the controller through a corresponding electrical connection, and wherein the receiver transmits the first and the second signals to the controller,
3. The electric iron according to claim 1, wherein the first and the second signals corresponds to the horizontal and the vertical positions of the iron, respectively, and wherein the first and second signals has a value of OV and 5V, respectively.
4. The electric iron according to claim 1, wherein the controller comprises of a timer operably connected with the controller and the receiver, and wherein the timer is pre-programmed to transmit appropriate power-off signals to the controller when the timer receives the first signal for the predetermined non-usage time interval.
5. The electric iron according to claim 3, wherein the timer is pre-programmed to transmit appropriate power-off signals to the controller when the timer receives the second signal for the predetermined non-usage time interval.
6. The electric iron according to claim 1, wherein the predetermined non-usage time intervals of the iron in the horizontal and vertical positions is 5 seconds and 20 seconds, respectively.
7. The electric iron according to claim 1, further including a plurality of pins is disposed in spaced apart relationship within a sole plate of iron, each of the pins are positioned between a corresponding solenoid cor] electrically connected with the power supply, and wherein each of the pins protrude outside an outer surface of the sole plate when the power supply is in the off-condition and retract inwardly within the sole plate when the power supply is in an on -condition.

8. The electric iron according to claim 1, wherein the controller is disposed outside the iron and positioned within a control box.
9. The electric iron according to claim 1, wherein the transmitter is a light emitting diode and the receiver is a photodetector.