FIELD OF THE INVENTION
[0001] The present invention, in general, relates to automatic stove knobs. Particularly, the invention relates to a smart knob configured to turn off the stove on the expiry of a pre-set time frame. More particularly, the present invention relates to an automatic stove knob control configured to regulate the gas supply volumes in a gas stove, including shutting off the supply entirely after a pre-set time frame without manual intervention, wherein said time frame may be set by . the user.
DESCRIPTION OF PRIOR ART
[0002] In the prior art literature, CN1396410 A teaches a means to automatically turn off a stove. But to implement said system, comprehensive changes must be made to an existing stove design, and is not suited for domestic use.
[0003] US Pat No. 5094259 teaches an automatic shut-off device for a gas stove featuring a gas safety valve device located between the stove intake pipe and the stove gas valve manifold. Said system works by cutting off the gas transmission to the stove head internally rather than turning off the knob.
[0004] US Pat No. 6239414 teaches a stove automatic shutoff control for boiling liquids. But said control is realized mechanically wherein said action is triggered by the difference in weight of the liquid w.r.t pre-set point level owing to evaporation.

[0005] US20070012310 A1 teaches a gas control knob for gas stove wherein the gas flow is regulated by means of an electromagnetic valve activated by pressing action or remote control action. But said invention is not designed for timed shut off. Also,.any electrical malfunction of the electromagnet system could cause the valve to malfunction.
[0006] US Pat No. 9,194,589 teaches a control knob for stoves and ovens includes a timer coupled with an automatic power shut-off feature. But said system works by turning off the cooking heating element. It is not adapted to be installed in gas stoves.
[0007] From the foregoing, it becomes apparent that there exists a need for a simple yet robust mechanism to automatically control the gas supply to the burner of a gas stove with respect to a set time attribute, with minimal human intervention.
[0008] My invention proposes an automatic stove knob control configured to vary the gas supply to the burner, including turning off the stove after a pre-set time frame, wherein said time frame may be set manually by the user. The invention also proposes a means to turn off the gas supply should the flame go out accidentally owing to external factors, or if the user fails to enter the time frame of cooking. The invention further provides a feature wherein the flame is automatically varied depending on the requirements specified in a recipe.

SUMMARY OF THE INVENTION
. [0009] It is therefore the primary objective of the present invention to propose an automatic stove knob control mechanism configured to turn off gas supply to a stove at the expiry of a pre-set time interval.
[0010] It is another object of the invention to propose a smart gas knob configured to dynamically regulate the gas supply to a stove depending upon the recipe selected by the user.
[0011] It is yet another object of the invention to propose a smart knob that is also adapted for manual operation.
[0012] It is a further another object of the invention to propose an automatic gas stove knob control adapted to be installed in a stove without altering any existing structure.
[0013] It is yet another object of the invention to provide an automatic gas stove knob control that is easy to install and maintain.
[0014] It is a further object of the invention to provide a smart knob that shuts off gas flow if the user fails to enter the time frame of cooking.

[0015] It is yet another object of the invention to have a means to shut off the gas flow if gas leakage is detected.
[0016] Accordingly, my invention proposes an automatic gas stove knob control configured to automatically regulate the gas supply volumes to a stove, including shutting off the supply after a pre-set time frame, said knob comprising of:
• first spur gear (1) is co-axially mounted on the knob shaft, wherein said spur gear is meshed with a second spur gear (2) configured to be driven by a bi-directional DC motor (3);
• microcontroller unit (6) having one or more memory configured to store one or more programs;
• motor controller (7) configured to operate said DC motor, wherein said microcontroller unit (6) interfaces a timer knob (8) configured to set the time of cooking, and the motor controller unit;
• position sensor unit to dynamically determine the angular position coordinates of the knob based on the voltage output of said unit at any given time, wherein said position coordinates are continuously fed back to the microcontroller;
• one or more temperature sensors mounted on a probe to measure the temperature continuously; and
• data interface configured to connect external storage devices and facilitate data transfer to the memory of the microcontroller unit.

[0017] My invention also proposes a a method to automatically regulate gas supply to a stove at the expiry of a set time frame, said method comprising the steps of:
• setting a time of cooking on the timer unit by the user after turning
on the knob;
• determining the angular position of the knob dynamically based on
"* the feedback from the position sensor unit by the microcontroller;
and
• signaling the motor controller to drive the spur gear (2) to turn off
the gas supply by the microcontroller on the expiry of said time
frame.
[0013] The other objectives, features, and advantages of the present invention will become more apparent from the ensuing detailed description of the invention, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF ACCOMPANYING FIGURES
[0018] FIG.1 illustrates the front view of the automatic stove knob control.
[0019] FIG.2 depicts the back side view of the automatic stove knob control
[0020] FIG.3 shows the timer knob and the whole system disposed in. a protected casing.

DETAILED DESCRIPTION OF INVENTION
[0021] The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However, in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail.
[0022] The preferred embodiment of the present invention discloses an automated gas stove knob control configured to turn off the stove (shut off the gas supply to the burner) on the expiry of a pre-set time interval. Referring to FIG.1, a first spur gear (1) is cp-axially mounted on the knob shaft, wherein said spur gear is meshed with a second spur gear (2) configured to be driven by a bi¬directional DC motor (3) powered from a DC source. Said motor is controlled by a motor controller (7) through a transistor switch. In one embodiment, the DC source is a 5V battery.
[0023] After turning on the stove knob (5), the user may set the time frame of cooking using the time setting knob (8) on the timer unit as in FIG.3. In another embodiment, said time setting means is realized electronically. A microcontroller

unit (6) interfaces the timer knob (8) and the motor controller unit (7). On the expiry of the set time frame, the microcontroller unit signals the motor controller to turn off the knob of the stove. The motor controller accordingly drives the second spur gear (2) to turn off the knob. The controller is configured to sense the current position of the knob using position sensors and suitably drive said spur gear (2) to turn said knob to the off position. Microcontroller and Motor Controller are shown in FIG.2.
[0024] More specifically, the motor controller features a position sensor unit comprising of one or more position sensors (potentiometer) configured to determine the angular position of the motor based on the voltage output at any given time. The voltage range is suitably mapped to a rotation of 0-360 degrees of the motor, wherein 0 degrees corresponds to 0V and 360 degrees corresponds to 5V respectively. In one exemplary instance of operation, depending upon the current position of the stove knob (5), the microcontroller (6) signals the motor controller (7) to turn the motor through suitable degrees to bring it to the off position. The position sensor unit is included in the case shown in FIG.3.
[0025] In another embodiment of the invention, the automatic gas stove knob control is configured to regulate the gas supply to suit temperature requirements for different food recipes as chosen by the user through a suitable interface. In one embodiment, said interface is a touch screen. The recipe information, including the required time of cooking, is stored in one or more of the memory of

the microcontroller. The temperature requirements of recipes in. a proprietary format may be uploaded to the microcontroller through USB or other data connectivity means including wireless communication means.
[0026] As per said embodiment, one or more temperature sensors are configured to continuously read the temperature in the vessel, wherein the microcontroller uses feedback from said sensors along with time attribute from the recipe to drive the motor controller to regulate the gas supplied at the burner dynamically.
[0027] In the preferred embodiment, said sensors are mounted on a probe adapted to be inserted into the cooking vessel. One of the leads (9) to theprobe is shown in FIG.3. In one scenario, for a particular recipe, if the instantaneous temperature exceeds the desired value, the controller reduces the gas supply to regulate the flame until the temperature drops down to desired temperature range. At the expiry of the set time frame, the controller turns the knob to off position, therein turning off the burner.
[0028] The automatic gas stove knob control also features a fail-safe mechanism wherein said knob turns itself off if the user fails to set the time duration of cooking. Further, said system features an integrated gas sensor to turn off the knob automatically should the flame go out due to any external factors such as air current or if the igniter fails to ignite the burner. Said gas sensor is interfaced with the microcontroller unit wherein said microcontroller uses the feedback from

the gas sensor to continuously monitor the gas levels. If said gas levels exceed a pre-set threshold, the controller signals the motor controller to turn off the knob.
[0029] The preferred embodiment of the present invention may also include mobile apps through which the smart knob could be controlled by the user.
[0030] Although the present invention has been described.in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention unless they depart there from.

I Claim
1. An automatic stove knob control configured to regulate gas supply to a
stove, including shutting off the supply after a pre-set time frame, said
knob comprising of:
• first spur gear (1) is co-axially mounted on the knob shaft, behind the knob, wherein said spur gear is meshed with a second spur gear (2) configured to be driven by a bi-directional DC motor (3);
• microcontroller unit (6) having one or more memory configured to store one or more programs;
• motor controller (7) configured to operate said DC motor, wherein said microcontroller unit (6) interfaces a timer knob (8) configured to set the time of cooking and the microcontroller unit;
• position sensor unit to dynamically determine the angular position coordinates of the knob based on the voltage output of said unit at any given time, wherein said position coordinates are continuously fed back to the microcontroller;
• one or more temperature sensors mounted on at least one probe to measure the temperature continuously; and
• data interface configured to connect external storage devices and facilitate data transfer to the memory of the microcontroller unit.
2. The automatic gas stove knob control as claimed in claim 1, wherein the
microcontroller is configured to signal the motor controller to drive the

motor based on the instructions stored in its memory.
3. The automatic gas stove knob control as claimed in claim 2, wherein at least one of the instructions is a recipe.
4. The automatic gas stove knob control as claimed in claim 1, wherein the microcontroller uses feedback from temperature sensors along with the time attribute from the timer unit to signal the motor controller to regulate the gas supplied at the burner dynamically.
5. The automatic gas stove knob control as claimed in claim 1, wherein the motor controller is configured to turn off the gas supply if the user fails to enter the time of cooking.
6. The automatic gas stove knob control as claimed in claim 1, wherein the voltage output of the position sensor unit is mapped to a rotation of 0-360 degrees of the motor.
7. A method to automatically regulate gas supply to a stove at the expiry of a set time frame, said method comprising the steps of:

• setting a time of cooking on the timer unit by the user after turning on the knob;
• determining the angular position of the knob dynamically based on the feedback from the position sensor unit by the microcontroller;

and
• signaling the motor controller to drive the spur gear (2) to turn off
the gas supply by the microcontroller on the expiry of said time
frame.
8. A method to regulate the gas supply based on a stored recipe, said method comprising the steps of:
• choosing a recipe by the user on a user interface;
• dynamically adjusting the knob position based on the feedback from the temperature sensors mounted on the probe and recipe instructions, by the microcontroller; and
• turning off the gas supply at the expiry of the required time of cooking specified in the recipe or the time frame set on the timer unit by the user.