DESC:FIELD OF THE INVENTION
The present invention relates generally to a timed shut-off valve to be used in natural gas fuelled burners and more particularly to an automatic shut-off valve for stopping further fuel flow in the absence of a flame in the burner.

BACKGROUND ART
In many industrial/appliance applications, the fuel supply to the furnace is to be shut-down immediately if the furnace suddenly malfunctions during its operation. In such application, use of ON/OFF valve which automatically closes when the furnace malfunction acts as a safety measure. The ON/OFF valve is connected in the pipeline just before the furnace. Conventional valves for gas burners are generally turned ON or OFF by means of an valve knob. It is known that gas fuel continue to be sent to the burner even in the absence of a flame to burn the fuel resulting in gas leak and major fire accidents. This is more so when the valve know is accidentally opened or an existing flame is extinguished by a gush of wind and left unattended. A number of solutions exist in the art to address this safety hazard. More common solution is to position a thermo-sensors near the burner, the thermo-sensors triggering a closing mechanism when the temperature around the burner is lower than a threshold value. They are generally time based, that is the flame must not exist for a period of time for the temperature to go lower than the threshold value, the sensor conveys that information to a closing mechanism to close the value. The closure is not instantaneous.

US5094259A discloses an automatic shut-off device for a gas stove, and more particularly, a safety valve control device that can be retrofitted between the gas inlet pipe and the catch base of the stove. The device includes a coupling such that operation of the knob of the gas stove at the time operates the circuit of a gas safety valve control device. This operation causes the forward movement of a function shaft of the gas safety valve device and opens the gas intake valve to supply the gas to the stove burner. The function shaft is also subject to the control by an electromagnetic control rod to maintain the open state of the gas intake valve. In case the fire goes out accidently, the circuit device energizes an electromagnetic coil to attract upwardly an electromagnetic control rod, thereby disconnecting the function shaft, which is spring loaded, and which in turn operates the gas intake valve. This action thus disconnects the gas supply to the stove. Also, if the cooking time is too long, and the fire does not go out (e.g., one forgets to turn off the gas) or the gas at the stove burner cannot be ignited within the given time, the device will also shut off automatically the gas intake valve.

CN2851893Y discloses a flameout gas stove with a dual gas leakage preventing and protecting function, which comprises a power supply (1), an air inlet pipe (2), a burner (3) and an igniter assembly, wherein the inner side of the burner (3) is provided with a thermocouple (4) and an igniting needle (5), and the thermocouple (4) is connected with an electromagnetic valve (6); the igniting needle is connected with the igniter assembly through a conducting wire. The igniter assembly, the power supply (1), the thermocouple (4) and the igniting needle (5) are separately connected with an electronic timing controller (7) through conducting wires. The utility model also comprises a self-absorption valve (8) which is installed on the air inlet pipe (2), and the self-absorption valve (8) is connected with the electronic timing controller (7) through a conducting wire. The utility model has the advantages that due to the adoption of the timing flameout technique, the gas stove can automatically cut off a gas circuit without need for users to watch aside at the same time of using the gas stove, and due to the adoption of a dual cutting off protective device, the utility model can safely cut off the gas circuit no matter after completing timing combustion or in the state of abnormal flameout when a main valve of a switch is not closed by hand, without occurring unsafe factors.

IN318408 teaches an invention invention comprising of a temperature sensor and a stove knob mounted on a spring loaded wheel. Temperature sensor is placed touching the burner of the gas stove (or in proximity to the burner). It senses the variation of burner’s temperature and whenever the temperature falls below a particular threshold, it activates the actuation mechanism to release the spring loaded wheel. Once released, the spring loaded wheel rotates back taking along the stove knob to “OFF” position resulting in the shut-off of the gas supply to the burner.

GB1482147A provides a gas control valve assembly comprising a first valve; a manually operable control means, including a rotary and axially movable shaft, for controlling the flow of gas between an inlet and outlet of the assembly; a second, safety, valve for controlling said flow of gas; an electromagnet having an armature movable from a first to a second position upon axial movement of the shaft, the electromagnet being operable to retain the armature in said second position when the electromagnet is energised in response to a thermocouple sensing a flame; two levers one engaging the armature and the other connected to the safety valve; and a latch releasably connecting together the two levers, and hence the safety valve and armature, so that upon said axial movement of the shaft the safety valve is moved to its open position as the armature is moved to said second position, rotation of the shaft to terminate the gas flow causing the unlatching of the latch, and hence the levers, to permit the safety valve to move to its closed position even though the electromagnet is still energized, the latch relatching when the armature returns to its first position upon de-energisation of the electromagnet and when the shaft is moved from its unlatching position.

This prior art provides for a safety value in addition to the conventional valve, wherein the safety valve is closed by the operation of the closing mechanism triggered by the thermosensor.

As explained above, the prior art solutions are entirely dependent on electro-mechanical solutions or takes considerable amount of time to close the valve. The teachings of the prior art enables closure of the valve only after the gas valve is turned on and the burner alighted. It does not enable prevention of accidental switching on of the gas burner.

The devices known in the art either sense the gas, or work on gas supply by using complex electromechanical devices. There is a need in the art to develop a non-electronic, non-electrical, user operable device for arresting gas leaks in gas stoves and prevent fire hazards.

Therefore, there exists a need in the art for a safety valve that is simple, fail proof, and instantaneous.

SUMMARY OF THE INVENTION
The present invention discloses a novel mechanism of temperature actuated ON/OFF valve. ON/OFF-valves are used in various industries, machines, appliances for variety of reasons. Their function is to either allow the flow or acts to prevent the flow of fluids through a pipeline under specific circumstances. The present invention’s ON/OFF valve is having automatic self-closing mechanism which is fully passive (it does not use any external electrical power for its operation). Also, this ON/OFF valve uses very less components and is designed in a way to reduce the assembly time which enables it for mass production and reduces its manufacturing cost resulting into cost benefits to its customers. The component’s design and the mechanism of the ON/OFF valve makes its operational reliability very high. One of the primary purposes of the disclosed ON/OFF valve is in industries where, in case of any malfunction in the furnace, the ON/OFF valve safely shut-downs the supply of fuel (like gasoline, furnace oil, gas etc.) to the furnace without any human intervention.

BRIEF DESCRIPTION OF THE DRAWINGS
FIG.1 is the side view of the assembled embodiment of the invention
FIGs.2 (a),(b) show the internal components of an embodiment of the invention.
Fig.3 shows the sectional view of an embodiment of the invention.
Fig.4 shows the sectional view of an feature of an embodiment of the invention.
Fig.5 shows the sectional side view of certain features of an embodiment of the invention
Fig.6 shows an operation of an embodiment of the invention
Fig.7 shows an operation of an embodiment of the invention
Fig.8 shows an operation of an embodiment of the invention
Fig.9 shows an operation of an embodiment of the invention
Fig.10 shows an operation of an embodiment of the invention
Fig.11 shows an operation of an embodiment of the invention
Fig.12 shows an operation of an embodiment of the invention
Fig.13 shows an operation of an embodiment of the invention
Fig.14 shows an operation of an embodiment of the invention
Fig.15 shows an operation of an embodiment of the invention
Fig.16 shows an operation of an embodiment of the invention
Fig.17 shows an operation of an embodiment of the invention
Fig.18 shows an operation of an embodiment of the invention
Fig.19 shows the operation of an embodiment of the invention when ‘flange projection’ and ‘arc’ are not present
Fig.20 shows the operation of an embodiment of the invention

DETAILED DESCRIPTION OF THE INVENTION
In the present invention, a temperature sensor like a thermocouple, thermopile etc. is used for sensing the presence/absence of the flame on the furnace.

The fully assembled ‘temperature actuated ON/OFF valve’ is shown in Fig.1. The ON/OFF valve comprises of two specially designed parts: a) ‘valve body (01)’ and b) ‘valve bonnet (02)’ which are joined together to form the casing of this valve. Fig.2a,2b depicts images showing the internal views of the ON/OFF valve. From Fig.2a,2b, all the internal components and their arrangement on ‘valve body (01)’ and ‘valve bonnet (02)’ can be seen. As can be seen from Fig.1 and Fig.2a, 2b, following are the major internal components: ‘plug (06)’, valve stem (10)’, ‘plunger (13)’, ‘solenoid coil (20)’, ‘link (21)’, ‘geared-projected-flange (27)’, ‘spring (35)’, ‘stopping rubber (37)’, ‘valve handle (38)’ and ‘thermo-sensor (41)’. The ‘valve body (01)’ is specially designed, having various features, to give functional support to the components involved in the ON/OFF valve operation. The ‘valve body (01)’ comprises of an ‘input port (03)’ and an ‘output port (04)’ for the flow of fuel through it. The ‘valve body (01)’ houses a ‘plug (06)’. This ‘plug (06)’ has a ‘through port (07)’ and an ‘exit port (08)’. The end of the ‘plug (06)’ is in the form of a ‘plate (09)’. It can have more number of ‘through ports (07)’ of variable size if different flows are required through the valve. The ‘plug (06)’ is seated on a ‘valve seat (05)’ leading to a permanent alignment of the ‘exit port (08)’ of the ‘plug (06)’ and the ‘output port (04)’ on the ‘valve body (01)’ as can be seen in Fig.3 & 4.

The ‘valve bonnet (02)’ provides the rotation guide and support to the ‘valve stem (10)’ of the ON/OFF valve as seen in Fig.4. The ‘valve stem (10)’ of this ON/OFF valve has a special structure. This ‘valve stem (10)’ comprises of two ‘fins (11)’ (The number of ‘fins (11)’ can be one or multiple but with multiple ‘fins (11)’, the rotational reliability of the ‘valve stem (10)’ is good.). Also, there is a ‘groove (12)’ at the end of the ‘valve stem (10)’. This ‘valve stem (10)’ gets coupled with the ‘plug (06)’ by insertion of ‘plate (09)’ of the ‘plug (06)’ into the ‘groove (12)’ of the ‘valve stem (10)’ as can be seen in Fig.3. Along with providing support to the ‘valve stem (10)’ (as ‘valve stem (10)’ passes through the ‘hole’ of the ‘valve bonnet (02)’), the ‘valve bonnet (02)’, through its various features, gives support to other internal components which are involved in the mechanism of the ON/OFF valve as referred in Fig.2(a).

Now, the components involved in the mechanism of this ON/OFF valve shall be discussed. One of the important components of this ON/OFF valve is ‘plunger (13)’. This ‘plunger (13)’ rests on the ‘valve bonnet (02)’. The ‘valve bonnet (02)’ supports the ‘plunger (13)’ by housing one its end in ‘support-housing (14)’ present in ‘valve bonnet (02)’. The ‘plunger (13)’ slides “to and fro” in a linear motion on the ‘guide (15)’ present in the ‘valve bonnet (02)’ as shown in Fig.3 and 5. (sliding direction shown by dashed line in Fig.5). The ‘plunger (13)’ is having ‘U-shaped gap (16)’ in its mid-region area. There are two ‘protrusions 1 (17) & 2 (18)’, one at each end of the ‘U-shaped gap (16)’. One side of this ‘plunger (13)’ is connected to a ‘metal-ingot (19)’ and the other side of the ‘plunger (13)’ is supported by the ‘support-housing (14)’ of the ‘valve bonnet (02)’ as can be seen in Figs.3 and 5. A ‘solenoid coil (20)’, which is housed in ‘valve body (01)’, is located just opposite to the ‘metal-ingot (19)’ as displayed in Fig.1.

There is a component called ‘link (21)’. The ‘link (21)’ is having a special geometry. One end of this ‘link (21)’ is in a form of an inclined ‘wedge (22)’. The other end of the ‘link (21)’ forms a combination of an ‘intermittent gear (23)’ and an ‘arc (24)’ as shown in Fig.07 & 09. The ‘arc (24)’ plays a key role in positional locking of the ‘link (21)’. There are two co-axials ‘rods (25)’, one on each end of the ‘link (21)’. One ‘rod’ is hinged on the ‘hinge-support (26)’ of the ’valve bonnet (02)’ and the other ‘rod’ of the ‘link (21)’ is hinged at ‘hinge-support (26)’ of the ‘valve body (01)’. This hinging allows the ‘link (21)’ to rotate freely about the axis of the two rods (25) as can be seen in the cross-section image shown in Fig.05.

Another important component which is mounted in the ‘valve bonnet (02)’ is a ‘geared-projected-flange (27)’. The ‘geared-projected-flange (27)’ is in the form of a ‘flange (28)’. It has ‘intermittent gear teeth (29)’ at the circumference of the ‘flange (28)’. Also, the portion of the circumference of the ‘flange (28)’ which comes after the ‘intermittent gear teeth (29)’ is partially projected. This partially projected circumference of the ‘flange (28)’ can also be termed as ‘flange projection (30)’. One end of the ‘flange projection (30)’ terminates into an inclined plane called as a ‘braking-ramp (31)’. The ’flange (28)’ also incorporates two or multiple ‘bars (32)’. The ‘geared-projected-flange (27)’ is hollow at its center. Also, the ‘geared-projected-flange (27)’ incorporates a ‘coupling groove (33)’. The ‘geared-projected-flange (27)’ is shown in its two images in Fig.09. The mounting of the ‘geared-projected-flange (27)’ on the flange-pivot of ‘valve bonnet’ (2)’ is depicted in Fig.07.

The ‘flange projection (30)’ of the ‘geared-projected-flange (27)’ locks the position of the ‘link (21)’ whenever the ‘flange projection (30)’ of the ‘geared-projected-flange (27)’ and the ‘arc (24)’ of the ‘link (21)’ are aligned to each other as can be seen in Fig.07. The locking of the ‘link (21)’ happens as follows: as the ‘link (21)’ tries to rotate in either direction about the axis of the ‘rods (25)’ of the ‘link (21)’, the ‘arc (24)’ of the ‘link (21)’ is unable to move as its movement is restricted by being in contact with the ‘flange projection (30)’ of the ‘geared-projected-flange (27)’. Hence, the ‘link (21)’ is unable to rotate in any direction and is positionally locked.

The ‘geared-projected-flange (27)’ is loaded by a ‘spring (35)’. The ‘spring (35)’ can be of different type like a circular spring or a spiral spring. The ‘spring (35)’ is housed in the ‘valve bonnet (02)’ with one of its ends fixed on the ‘valve bonnet (02)’ as seen in one of the images of Fig.2a, 2b. The other end of the ‘spring (35)’ is coupled to the ‘coupling groove (33)’ present in the ‘geared-projected-flange (27)’, as is seen in Fig.2a. This arrangement of placing the ‘spring (35)’ (as is seen in Fig.2) enables the twisting of the ‘spring (35)’when the ‘geared-projected-flange (27)’ is rotated in one particular direction (refer the image in Fig.07 for rotational direction of ‘geared-projected-flange (27)’). Twisting of the ‘spring (35)‘ energizes the ‘spring (35)’ and hence the coupled ‘geared-projected-flange (27)’ also gets energized. This energized ‘geared-projected-flange (27)’ has the tendency to self-rotate in opposite direction as the ‘spring (35)’ tries to un-wind.

The full assembly of the ON/OFF valve is very simple and takes very less time to assemble. It is to be noted that the orientation and position of all the components during assembly results into the OFF position of the ON/OFF valve. First, the ‘valve bonnet (02)’ along with its housed and supported components are assembled. ‘Spring (35)’ is placed first on the ‘valve bonnet (02)’ by fixing one of its ends on the ‘groove (12)’ of ‘valve bonnet (02)’ (refer Fig.2a). The ‘geared-projected-flange (27)’ is placed over the ‘spring (35)’ by getting mounted on the ‘flange-pivot ’ of the ‘valve bonnet (02)’. During this mounting of the ‘geared-projected-flange (27)’, the other end of the ‘spring (35)’ gets coupled to the ‘geared-projected-flange (27)’ by getting itself inserted into the ‘coupling groove (33)’ present in the ‘geared-projected-flange (27)’ as already seen in Fig. 2b. The mounted ‘geared-projected-flange (27)’ on the ‘valve bonnet (02)’ is shown in Fig.2a. For securing the hinge of the ‘geared-projected-flange’(27) on the flange-pivot of ‘valve bonnet’ (2), fasteners like circlips are used. Finally, ‘stopping rubber (37)’ is mounted on the ‘valve bonnet (02)’ where it touches the plane of ‘braking-ramp (31)’ of the ‘geared-projected-flange (27)’ as shown in Fig.2(b). The ‘spring (35)’ is in un-winded condition in the form and location at which the ‘spring (35)’ is placed on the ‘valve bonnet (02)’ during this assembly. Hence, the coupled ‘geared-projected-flange (27)’ is also un-energized.

After ‘spring (35)’ and ‘geared-projected-flange (27)’ are assembled, the ‘valve stem (10)’ is inserted into the ‘hole’ which is at the center of the ‘flange-pivot’ of the ‘valve bonnet (02)’. The ‘valve stem (10)’ is inserted in such a way that the two ‘fins (11)’ of the ‘valve stem (10)’ touches the two ‘bars (32)’ of the ‘geared-projected-flange (27)’ refer the position of ‘fins (11)’ and ‘bars (32)’ in Fig.2(a).

After this, ‘plunger (13)’ is placed on the ‘guide (15)’ of the ‘valve bonnet (02)’ by inserting one of its end in the ‘support-housing (14)’ of the ‘valve bonnet (02)’.

After this, the ‘link (21)’ is hinged by mounting one of its ‘rod’ in the ‘hinge-support (26)’ of the ‘valve bonnet (02)’ . The mounting position of the ‘link (21)’ is locked since the ‘arc (24)’ of the ‘link (21)’ and the ‘flange projection (30)’ of the ‘geared-projected-flange (27)’ are aligned. The dimensions of the ‘link (21)’ are such that, at ‘link (21)’s locked position, one of the corners of the ‘wedge (22)’ end of the ‘link (21)’ is just entering the ‘U-shaped gap (16)’ of the ‘plunger (13)’. The assembled positions of the ‘valve stem (10)’, ‘plunger (13)’ and ‘link (21)’ on the ‘valve bonnet (02)’ are shown in Fig.2(a).

After the assembly of ‘valve bonnet (02)’ and its supported components, the ‘valve body (01)’ is assembled with its supported components. As a first step, the ‘plug (06)’ is inserted and gets seated in the ‘valve body (01)’ in a way that the ‘exit port (08)’ of the ‘plug (06)’ and the ‘output port (04)’ of the ‘valve body (01)’ are aligned as can be seen in Fig.3. In this assembly position of the ‘plug (06)’, its ‘through port (07)’ does not align with the ‘input port (03)’ of the ‘valve body (01)’ as can be seen in Fig.04. The ‘solenoid coil (20)’ is placed inside a ‘hollow cylinder’ as seen in Fig.1.

After all this is done, the ‘valve body (01)’ is brought together with the ‘valve bonnet (02)’ in such a way that all their supported components come in alignment and placed together. When ‘valve body (01)’ and ‘valve bonnet (02)’ are brought together, following alignments takes place:

# The ‘metal-ingot (19)’ which is connected to the ‘plunger (13)’, comes in alignment with the ‘solenoid coil (20)’. At this position of the ‘metal-ingot (19)’, it does not make contact with the ‘solenoid coil (20)’. This non-contact position of ‘metal-ingot (19)’ and the ‘solenoid coil (20)’ can be seen in Fig.1.
# The ‘plate (09)’ of the ‘plug (06)’ gets inserted to the ‘groove (12)’ of the ‘valve stem (10)’ as shown in one of the cross-section images represented in Fig.03
# The other ‘rod’(25) of the ‘link (21)’ gets mounted to the ‘hinge-support (26)’ of the ‘valve body (01)’ as shown in Fig.05

The ‘valve body (01)’ and the ‘valve bonnet (02)’ are tightened together with the help of fasteners. Finally, a ‘valve handle (38)’ is connected over the ‘valve stem (10)’. The complete assembled ‘valve body (01)’ and ‘valve bonnet (02)’ are shown in Fig.1.

The temperature sensor like thermocouple or a thermopile(41) is connected to the terminals of the ‘solenoid coil (20)’ as can be seen in Fig.1. Following is the description of entire operation of this ON/OFF valve.

The operator can switch ON this ON/OFF valve by manually rotating a ‘valve handle (38)’ from OFF position to ON position as seen in Fig.06. During this rotation, the ‘valve stem (10)’ also gets rotated (since ‘valve handle (38)’ is connected to ‘valve stem (10)’) and the two ‘fins (11)’ of the ‘valve stem (10)’ pushes the two ‘bars (32)’ of the ‘geared-projected-flange (27)’ and hence the ‘geared-projected-flange (27)’ also gets rotated along with the rotating ‘valve stem (10)’ as can be seen in Fig.07.

When the ‘valve handle (38)’ is at OFF position, the ‘through port (07)’ of the ‘plug (06)’ is not aligned with the ‘input port (03)’ of the ‘valve body (01)’ and the fuel cannot pass through the ON/OFF valve as seen in one of the cross-section images depicted in Fig.03&04. During this rotation of the ‘valve handle (38)’ from OFF to ON position, the ‘plug (06)’ gets rotated (via the rotation of its coupled ‘valve stem (10)’) and its ‘through port (07)’ gets aligned to the input port (03) of the ‘valve body (01)’ once the ‘valve handle (38)’ reaches to the ON position as can be seen in cross-section image represented in Fig.08. At this ON position of the ‘valve handle (38)’, fuel is supplied to the furnace as the fuel flows to the ‘output port (04)’ from the ‘input port (03)’ of the ‘valve body (01)’, via the ‘through port (07)’ and ‘exit port (08)’ of the ’plug (06)’.

Also, during the initial rotational travel of ‘valve handle (38)’ from OFF to ON position, the ‘flange projection (30)’ of the rotating ‘geared-projected-flange (27)’ is in alignment of the ‘arc (24)’ of the ‘link (21)’. Due to this aligned position of ‘flange projection (30)’ and ‘arc (24)’, the ‘link (21)’ is in locked position and is unable to rotate as depicted in Fig.07. When the ‘valve handle (38)’ is nearing to the ON position, the ‘flange projection (30)’ comes out of alignment with the ‘arc (24)’ (refer one of the images of Fig.09, and along with that the ‘intermittent gear teeth (29)’ present at the circumference of the ‘geared-projected-flange (27)’ engages with the ‘intermittent gear (23)’ of the ‘link (21)’. Due to this coupling of both gears, the ‘link (21)’ also gets rotated along with the rotated ‘geared-projected-flange (27)’ as seen in image of Fig.09.

When the ‘link (21)’ gets rotated, the inclined ‘wedge (22)’ also moves inside the ‘U-shaped gap (16)’ of the ‘plunger (13)’ as can be seen in one of the images of Fig.10. This movement of the inclined ‘wedge (22)’ leads to the linear movement of ‘plunger (13)’ because of the pushing of one of the ‘protrusions 1 (17) & 2 (18)’ of the ‘plunger (13)’: ‘protrusion-1’ by one of the inclined faces of the moving ‘wedge (22)’: ‘inclined wedge face-1(39)’. This is shown in the other image of Fig.10. The ‘plunger (13)’ slides freely on a linear ‘guide (15)’ in the ‘valve bonnet (02)’. This linear movement of the ‘plunger (13)’ continues till the ‘valve handle (38)’ reaches exactly to the ON position. At this exact ON position of the ‘valve handle (38)’, the ‘metal-ingot (19)’ touches the face of the ‘solenoid coil (20)’ as depicted in Fig.11.

During the ON position of the ‘valve handle (38)’, fuel reaches the furnace and the furnace is ignited. The tip of the temperature sensor like thermocouple or thermopile senses the flame-heat and instantly generates an electric potential. This in-turn leads the ‘solenoid coil (20)’ to become an electromagnet since the temperature sensor is electrically connected to the ‘solenoid coil (20)’. Thus, the magnetic force of the ‘solenoid coil (20)’ attracts the ‘metal-ingot (19)’ and positionally locks the ‘plunger (13)’ as can be seen in Fig.12. Once the furnace is ignited, the operator leaves the ‘valve handle (38)’ and the fuel is continuously supplied to the furnace via the opened ON/OFF valve.

It is to be noted that during the turning of the ‘valve handle (38)’ from OFF to ON position, the ‘spring (35)’ also gets twisted due to the rotation of the ‘geared-projected-flange (27)’ as the ‘geared-projected-flange (27)’ and the ‘spring (35)’ are coupled to each other. Therefore, at the ON/opened position of the ON/OFF valve, as the ‘spring (35)’ tries to un-wind, the coupled ‘geared-projected-flange (27)’ has the tendency to self-rotate and push the ‘valve stem (10)’(through the pushing of two ‘fins (11)’ of ‘valve stem (10)’ by two ‘bars (32)’ of the ‘geared-projected-flange (27)’)to the closing rotational direction of the ON/OFF valve

But, even with the energized ‘spring (35)’ and its coupled ‘geared-projected-flange (27)’, the ‘valve stem (10)’ is unable to rotate towards the closing direction. This is because: even though the ‘geared-projected-flange (27)’ tries to self-rotate under the influence of the energized ‘spring (35)’, it gets stalled because its gear-coupled ‘link (21)’ is unable to rotate. The ‘link (21)’ is un-movable because the ‘protrusion-2’ of the positionally-locked ‘plunger (13)’ restricts the movement of ‘inclined wedge face-2(40)’ of the ‘wedge (22)’ portion of the ‘link (21)’ as seen in Fig.13. Therefore, in the presence of the furnace flame, the position of the ’plunger (13)’, ‘link (21)’ and ‘geared-projected-flange (27)’ are locked (these locked positions are shown in Fig.14). Two ‘bars (32)’ of the locked ‘geared-projected-flange (27)’ cannot push the two ‘fins (11)’ of the ‘valve stem (10)’. Hence, under the presence of furnace-flame, the ‘valve stem (10)’ cannot rotate and therefore the ‘plug (06)’ continues to remain in its opened position when the ON/OFF valve is in switched ON position.

Now, the automatic self-closing mechanism of the ON/OFF valve is described, under the condition: when the furnace suddenly malfunctions during its operation. If due to any reason, the furnace malfunctions, the furnace-flame ceases to exists. In such a scenario, the temperature sensor (like thermocouple/thermopile) senses low temperature and its corresponding generated electric potential falls and hence the electromagnetic effect of the ‘solenoid coil (20)’ ceases. Due to the absence of the magnetic field, the ‘solenoid coil (20)’ releases the ‘metal-ingot (19)’ of the ‘plunger (13)’ as seen in one of the images of Fig.15. Once the ‘plunger (13)’ is free, ‘protrusion-2’ of the ‘plunger (13)’ no longer holds the ‘inclined wedge face-2 (40)’ of the ‘wedge (22)’ portion of the ‘link (21)’ as referred in the other image of Fig.15. Thus, the ‘link (21)’ becomes free to rotate. Because of the ‘link (21)’ becoming free, the ‘geared-projected-flange (27)’ which is gear-coupled with the ‘link (21)’ rotates under the influence of the energized ‘spring (35)’ as shown in Fig.16. During this rotation of the ‘geared-projected-flange (27)’, two ‘bars (32)’ of the ‘geared-projected-flange (27)’ pushes two ‘fins (11)’ of the ‘valve stem (10)’ and hence the ‘valve stem (10)’ also rotates along with the ‘geared-projected-flange (27)’ towards the closing direction of the ON/OFF valve as depicted in one of the images of Fig.17.

As shown in both images of Fig.17, during the initial rotation of the ‘geared-projected-flange (27)’ towards the closing direction of ON/OFF valve, the ‘link (21)’, which is gear-coupled with the ‘geared-projected-flange (27)’, also rotates. Thus, the inclined ‘wedge (22)’ starts moving out of the ‘U-shaped gap (16)’ of the ‘plunger (13)’ thereby pushing the ‘plunger (13)’ away from the ‘solenoid coil (20)’. This is shown in one of the images of Fig.17. At one point during this ‘geared-projected-flange (27)’ rotation, the ‘intermittent gear teeth (29)’ of the ‘geared-projected-flange (27) ’ gets de-coupled with the ‘intermittent gear (23)’ of the ‘link (21)’ (refer the image of Fig.18)and subsequently the ‘flange projection (30)’ of the rotating ‘geared-projected-flange (27)’ comes in alignment of the ‘arc (24)’ of the rotating ‘link (21)’ as can be seen in Fig.18. This aligned position of the ‘flange projection (30)’ and the ‘arc (24)’ immediately locks the ‘link (21)’. At this locked position of the ‘link (21)’, one of the corners of the ‘wedge (22)’ portion of the ‘link (21)’ is just at the entrance of the ‘U-shaped gap (16)’ of the ‘plunger (13)’. Thus, the ‘link (21)’ and the ‘plunger (13)’ attains their original position as it was when the ON/OFF valve was at OFF position. Whereas, the ‘geared-projected-flange (27)’ continues to rotate along with the ‘valve stem (10)’ towards the closing direction of the ON/OFF valve. This is shown in Fig.18.

It is to be noted that the presence of ‘flange projection (30)’ and the ‘arc (24)’ is must if the ON/OFF valve is to be operated reliably in each and every cycle of operation. Following is the reason for the importance of the ‘flange projection (30)’ and the ‘arc (24)’: during the auto-closing of the ON/OFF valve and assuming the ‘flange projection (30)’ and ‘arc (24)’ are not present, the rotating ‘link (21)’ will never be locked and will keep moving due to inertia even after it gets de-coupled with the rotating ‘geared-projected-flange (27)’ as seen in one of the images Fig.19. In such a case, in the next round of switching ON operation of the ON/OFF valve, the gear coupling between the ‘geared-projected-flange (27)’ and the ‘link (21)’ might never happen since the position of the ‘link (21)’ cannot be determined. If the gear-coupling between the ‘geared-projected-flange (27)’ and the ‘link (21)’ gets hampered (refer the other image of Fig.19), during the next round of switching ON operation, the ‘link (21)’ will not rotate and hence the ‘plunger (13)’ will not move towards the ‘solenoid coil (20)’. Therefore, the ON switching of the ON/OFF valve will never happen.

Now, continuing with the discussion on the automatic closing mechanism of the ON/OFF valve, under absence of furnace flame, even after the ‘link (21)’ gets locked and the ‘link (21)’ and the ‘plunger (13)’ attains their original position, the ‘geared-projected-flange (27)’ and the ‘valve stem (10)’ continues to rotate towards the OFF position of the ON/OFF valve as depicted in Fig.20. Once ‘geared-projected-flange (27)’ reaches towards the OFF position of the ON/OFF valve, it gets stopped by the ’stopping rubber (37)’. The inclined plane of the ‘braking-ramp (31)’ present at the circumference of the ‘geared-projected-flange (27)’, rubs with the ’stopping rubber (37)’ thereby reducing the speed of ‘geared-projected-flange (27)’ and eventually making it stop. This is shown in Fig.20. Because of the inclined plane structure of the ‘braking-ramp (31)’, the rotational speed of the ‘geared-projected-flange (27)’ is reduced slowly to zero avoiding any sudden jerk which is good for a reliable operation. Once, the ‘geared-projected-flange (27)’ halts, the ‘valve stem (10)’ also stops at the OFF position of the ON/OFF valve. During automatic closing of ON/OFF valve, rotation of the ‘valve stem (10)’ also rotates its coupled ‘plug (06)’. As ‘valve stem (10)’ stops at the OFF position of the ON/OFF valve, its coupled ‘plug (06)’ also gets stopped as can be seen in Fig.20. At the OFF position of the ON/OFF valve, the ‘through port (07)’ of the ‘plug (06)’ mis-aligns with the ‘input port (03)’ of the ‘valve body (01)’ and hence, the fuel supply to the furnace is blocked. This can be seen in Fig.20. Thus, the fuel supply to the furnace is automatically shut down by the ON/OFF valve when there is malfunction in the furnace.

It is to be noted that, the ON/OFF valve disclosed in the present invention can also be applied to other systems/applications where automatic shut-down of the fluid (other than fuel) supply is required based on parameters other than temperature. This can be done by switching the current through the solenoid by use of sensors/transducers/controllers.
,CLAIMS:We claim

1. A device for safely delivering combustible fuel to a furnace and to automatically shut-down the fuel to the furnace comprising of:
a ‘valve body’ (1) having an ‘input port’ (3) and an ‘output port’ (4) for the passage of fuel through it;
a ‘valve bonnet’ (2) joined with the ‘valve body’ (1) to form the outer casing of the device;
a ‘valve stem’ (10) passing through the ‘valve bonnet’ (2), the ‘valve stem’ (10) has at-least one ‘fin’ (11) and a ‘groove’ (12) at one of its end, the other end of the ‘valve stem’ (10) mounts the ‘valve handle’ (38), the ‘groove’ (12) of the ‘valve stem’ (10) is coupled to the ‘plate’ (9) of a ‘plug’ (6), in that rotating the ‘valve handle’ (38) rotates the ‘valve stem’ (10) and ‘plug’ (06), the ‘plug’ (6) has a ‘through port’ (7) and an ‘exit port’ (8) so as to allow the passage of fuel from ‘input port’ (3) to ‘output port’ (4) via its ‘exit port’ (8) when ‘through port’ (7) is aligned to ‘input port’ (3);
a ’geared-projected-flange’ (27) mounted on the ‘valve bonnet’ (02) having at-least one ‘bar’ (32), the circumference of the ‘geared-projected-flange’ (27) has ‘intermittent gear teeth’ (29) and ‘flange projection’ (30), in that rotating the ‘valve handle’ (38) towards ON position rotates the ‘geared-projected-flange’ (27) by pushing of ‘bar’ (32) by the ‘fin’ (11) of the ‘valve stem’ (10), ‘spring’ (35) coupled to the ‘valve bonnet’ (2) and the ‘geared-projected-flange’ (27) is configured to an energized state by the spring when the ‘valve handle’ (38) rotates to ON position;
a ‘plunger’ (13) housed in a ‘support-housing’ (14) and a ‘guide’ (15) within the ‘valve bonnet’ (02), the ‘plunger’ (13) having protrusions 1 (17) & 2 (18) forming an ‘U-shaped gap’ (16), one end of the ‘plunger’ (13) is a ‘metal-ingot’ (19) which is adapted to be attracted and released by an electro-magnet formed by a ‘solenoid coil’ (20), the coil in turn powered by a thermo-sensor (41) in contact with the flame of the furnace; and
a ‘link’ (21) having a combination of ‘intermittent gear’ (23) and an ‘arc’ (24) at one of its end, the other end of the ‘link’ (21) is having a ‘wedge’ (22) which has two inclined faces ‘inclined wedge face-1’ (39) and ‘inclined wedge face-2’ (40), the ‘link’ (21) rotates when ‘intermittent gear’ (23) engages the ‘intermittent gear teeth’ (29), the ‘link’ positionally locks when ‘arc’ (24) aligns with the ‘flange projection’ (30), the ‘wedge’ (22) is adapted to move within the ‘U-shaped gap’ (16) of the plunger (13) when the ‘link’ (21) is rotated, the ‘plunger’ (13) slides linearly ‘to-and-fro’ on the ‘guide’ (15) by the pushing of its ‘protrusions’ (17)(18) from the ‘inclined wedge faces’ (30)(40) of the ‘wedge’(22)
wherein, when the ‘valve handle’ (38) is rotated to ON position, the ‘valve stem’ (10) along with the ‘plug’ (6) rotates to align with the ‘input port’ (3) for supply of the fuel to the furnace, rotating ‘valve stem’ (10) also simultaneously rotates the ‘geared-projected-flange’ (27) and thereby rotates the ‘link’ (21) to push the ‘plunger’ (13) towards the ‘solenoid coil’ (20), and once the flame is ignited the ‘plunger’ (13) is locked because of the magnetised ‘solenoid coil’ (20) attracting and retaining in its place the ‘metal-ingot’ (19), a continuous fuel supply is thus maintained to the burning furnace, if flame extinguishes then the plunger is released by the demagnetised ‘solenoid coil’(20) instantaneously thereby releasing the ‘link’ (21) which inturn releases the “geared-projected-flange” (27) and pushes the valve stem (10) towards OFF position thereby cutting off the gas supply to the burner instantaneously.

2. The device as claimed in claim 1, wherein, the ‘valve handle’ (38) is kept in open position only as long as there is flame in the furnace.

3. The device as claimed in claim 1, wherein ‘intermittent gear’ (23) of the ‘link’ (21) is positioned below the ‘arc’ (24).

4. The device as claimed in claim 1, wherein the intermittent gear teeth’ (29) on the circumference of the ‘geared projected flange’ (27) engages the ‘intermittent gear‘ (23) on the link (21) only when the ‘valve handle’ (38) goes to ON position to start the operation of the ON/OFF valve.