Claims:WE CLAIM:

1. A novel lock means for conventional pressure cooker with a removable lid and a pan each having a circumferential interlocking lug and rim engaging means around the entire periphery of the lid and the pan for closing the lid onto the pan comprising :
- a pan with an outside profiled rim edge,
- a lid with a profiled rim edge that forms an inner recess covering the outside rim of the said pan and provided with a sealing ring housed in the hollow edge of the said lid,
- an upper handle affixed to the said lid,
- a lower handle affixed to the said pan,
- a profiled slot/recess on the rim of the said lid corresponding to a portion within upper handle affixing portion and adapted to receive said locking means,
- a top steam release aperture through said lid,
- a cooking pressure regulating valve means housed on the lid in the said top steam release aperture having a valve which is lifted upwardly by pressure in an interior of said pan and which movement is used for actuating locking means of the pressure cooker,
- a locking means housed pivotally in said upper handle, having a locking member top end, a profiled mid-section, and a locking member bottom end, arranged such that the vertically moving top free end of the locking means terminating just above the moving valve of the valve means, and the other horizontally sliding bottom end terminating free along the rim of the lid and at a location corresponding to the profiled slot on the rim of the lid but away from lid lug, the said locking means moveable with the moving motion of the valve of the valve means,
- the said arrangement characterized in the said pressure regulating valve means fixing said lock means in a locked position when said valve of valve means is raised upwardly by correspondingly lifting upwardly the top end of the lock means and thereby sliding and extending the bottom end of the lock means inwardly and horizontally into and through the profiled slot in the rim of the lid to contact the lid lug, thereby preventing the disengagement of the said lid from said pan of the pressure cooker.

2. A pressure cooker having a lock means as claimed in claim 1.

3. The pressure cooker and lock means as claimed in claim 1 and 2, wherein the lock means may include a top cap.

4. The pressure cooker and lock means as claimed in claim 1 and 2, wherein the lock means includes a pin arranged between the top end and bottom end and allows pivotal motion of the lock means.

5. The pressure cooker and lock means as claimed in claim 4, wherein the arrangement includes access to pin, from the lid which pin when downwardly depressed from top, pushes correspondingly downward the pressure valve into the pan and enabling manual pressure release from the interior of the pan through the pressure regulating means.

6. The pressure cooker as claimed in claim 1, wherein the pressure regulating valve means may include slit arrangement for releasing excess steam.
, Description:FIELD OF INVENTION:
The invention relates to pressure cookers embodying improved safety means preventing the detachment of the lid from the pan when the pressure inside the closed pan is above a predetermined value.

OBJECT OF THE INVENTION:
The first object is to improve the conventional pressure cooker with an improved locking means when under pressure.

The second object is to improve the conventional pressure cooker with a simple mechanical lock means.

The third object is to improve the conventional pressure cooker which is operable with a self-reset lock mechanism.

The fourth object is to improve the conventional pressure cooker with a lock means but which exhibits simple industrial manufacture.

The fifth object is to improve the conventional pressure cooker by adding lock means but which can operate with other already existing safety devices in the pressure cooker.

The sixth object is to improve the conventional pressure cooker in which the design of lock means is simple at component level.

The seventh object is to improve the conventional pressure cooker with a novel lock means which does not interfere with dimensional constraints on the existing pressure cooker.

KNOWN PRIOR ART TO INVENTORS:
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Radar, S. Coop. Pressure cooker with bayonet closure and weight valve
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Boehm Hans Georg Steam pressure cooking pot with a seal securing the inside space of the pot against a drop in pressure
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DESCRIPTION OF THE INVENTION:
The invention discloses an improved pressure cooker having a top opening cooking pan and a lid thereof.

The New designed Auto lock pressure cooker is for a outer lid pressure-cooking appliance comprising a pressure vessel, Auto Lock Operates with weight balancing principle, Auto lock is aligned and fixed with a pin to lid handle, Secondary safety device which is fixed to the lid hole which will be free floating, the Auto lock will be floated on the secondary safety device .when the pressure within the vessel attains a Minimum value the Secondary safety device seals with the lid and the auto lock lifts up and the foot of the Auto lock engages with body lug for which the cooker cannot be opened under pressure condition.

The present invention relates to a Auto lock for outer lid pressure cooker, it acts such as an auto cooker. An user cannot open the cooker under pressure cooker due to locking means which interlocks the lid and pan under pressure.

The Present invention consists of the following parts:
1. Body (pan)
2. Lid
3. Body handle (lower handle)
4. Lid handle (upper handle)
5. Auto lock (lock means)
6. Secondary safety device (pressure regulating valve means)
7. Auto lock cover (top cover)
8. Pin
9. Gasket (sealing ring)
10. Auto foot lock unlocking under zero pressure
11. Auto foot lock locking under pressure

A novel locking means for conventional pressure cooker with a removable lid and a pan each having a circumferential interlocking lug and rim engaging means around the entire periphery of the lid and the pan for closing the lid onto the pan comprising of a pan with an outside profiled rim edge, and a lid with a profiled rim edge that forms an inner recess covering the outside rim of the said pan and provided with a sealing ring housed in the hollow edge of the said lid. An upper handle is affixed to the said lid and a lower handle affixed to the said pan.

A profiled slot/recess is created on the rim of the said lid corresponding to a portion within upper handle affixing portion and adapted to receive said locking means.

A top steam release aperture is made through said lid as is known in any conventional pressure cooker.

A cooking pressure regulating valve means is housed on the lid in the said top steam release aperture having a valve which is lifted upwardly by pressure in an interior of said pan and which movement is used for actuating locking means of the pressure cooker,

A locking means is housed pivotally in said upper handle, having a locking member top end, a profiled mid-section, and a locking member bottom end, arranged such that the vertically moving top free end of the locking means terminating just above the moving valve of the valve means, and the other horizontally sliding bottom end terminating free along the rim of the lid and at a location corresponding to the profiled slot on the rim of the lid but away from lid lug, the said locking means moveable with the moving motion of the valve of the valve means. The said arrangement characterized in the said pressure regulating valve means fixing said lock means in a locked position when said valve of valve means is raised upwardly by correspondingly lifting upwardly the top end of the lock means and thereby sliding and extending the bottom end of the lock means inwardly and horizontally into and through the profiled slot in the rim of the lid to contact the lid lug, thereby preventing the disengagement of the said lid from said pan of the pressure cooker.

In another aspect, the pressure cooker having a locking means may include a top cap for the lock means.

In another aspect, the lock means includes a pin arranged between the top end and bottom end and allows pivotal motion of the lock means.

In another aspect, the arrangement includes access to pin, from the lid which pin when downwardly depressed from top, pushes correspondingly downward the pressure valve into the pan and enabling manual pressure release from the interior of the pan through the pressure regulating means.

In another aspect, the pressure regulating valve means may include slit arrangement for releasing excess steam.

DESCRIPTION OF DRAWINGS:

Fig. 1 This device is applicable to pressure-cooking appliances comprising a vessel on which the Auto lock is aligned and fixed with a pin on the lid handle as shown in the figure 1.0 , the lid has a Hole where the Secondary safety device is aligned and fitted , which will be free floating , The Auto Lock is free floating on top of the Secondary safety device.

Fig. 2The Lid handle is mounded to the lid by CSK screws, And Auto lock cap pressfitted with lid handle.

The Auto Lock pivots in the lid handle under the Minimum pressure condition, The Auto Lock Rotates As the secondary floats up and down directions and the Auto Lock foot which engages beneath on the slot opening of lid to lock the body lug which prevents from opening, as shown in the figure 2.0

The Figure 1.0 illustrates the Zero pressure condition of Auto Lock and secondary safety device wherein the bottom end/foot of lock means is not hindering the operation of relative motion of lid and pan.

The Figure 2.0 illustrates the pressure condition of Auto Lock and secondary safety device when the bottom end of foot of lock means is hindering the operation of relative motion of lid and pan.

The Figure 3.0 illustrates the Secondary safety device (pressure regulating valve means) and Auto lock (lock means) independently.

The Auto Lock and secondary Safety device performs varies functions to ensure safety and functions of the pressure cooker as detailed above.

WORKING PRINCIPLE:

This pressure cooker is a fully-sealed cooking container that builds cooking pressure by heating air, steam, and liquid, and trapping them inside the pan. The trapped steam increases the internal pressure and allows the temperature to rise. As liquid and foods inside the pressure cooker heat, the pressure cooker traps the heated liquid inside the pan as steam. This builds even more pressure, which forces the steam back through the foods, cooking and tenderizing them and blending the flavors. This results in condensed cooking time, which also saves energy, and is perfect for getting delicious dishes and foods on the table fast at any time, any day of the week. Furthermore, because less cooking liquid is needed, vitamins and nutrients remain in foods rather than being cooked away.

This device ensures that pressure is maintained inside the appliance while cooking above atmospheric pressure. Once the pressure inside the cooker reaches normal cooking pressure, the pressure regulator releases steam thus ensuring that excess pressure does not build up inside the cooker.

This device enables users to operate the pressure cooker in complete safety. The Auto Lock has a visual pressure indicator feature that lets the user know that the cooker is under pressure. The pin inside the Auto lock rises and lowers above the opening of the cover as internal cooking pressure rises and lowers. As pressure starts building inside the pressure cooker, internal cooking pressure pushes the pin inside the Auto Lock cover. This signals that your pressure cooker is under internal cooking pressure. The Auto Lock will release only if the pressure inside the cooker properly drops to a Safe level. Once cooking is complete and the pressure cooker is removed from the heat source, the pressure inside the pressure cooker will slowly drop back down and the visual pressure indicator pin will drop back flush with the cover. Try to release pressure by tilt or pressing the pin with a spoon or any other kitchen tool. If the pressure cooker is improperly closed, the Auto Lock will not allow internal cooking pressure to build up.

This unique safety system makes your pressure cooker completely safe even if the Pressure Regulator Knob fails to function due to overload or blockage of the Pressure Regulator Vent Tube. If the pressure inside the pressure cooker rises above the normal level due to blockage of the Pressure Regulator Vent Tube, a portion of the Secondary safety device has a slit, and excess pressure in the pressure cooker gently releasing the steam in a safe, controlled manner. The steam is released in a vertical direction. If and when the Controlled Slit Release, the stove should be turned off immediately. Allow the cooker to cool. When there is no pressure and the Visual Pressure Indicator has dropped (See User Instructions), you may open the cooker. Remove the gasket, clean it, and if necessary, clean the gasket seating area on the lid and body of the cooker. Reposition the gasket in the lid. Check and ensure that the Pressure Regulator Knob and Vent Tube are clean and clear. If the cooking process has raised the food volume past the recommended 2/3 capacity, remove any excess food and continue the cooking process. In addition, if the Pressure Regulator Knob and Vent Tube fails to function for any reason and the internal cooking pressure goes higher than usual, the Secondary safety device will start to operate as a pressure releasing device. This allows excess pressure, heat and steam to escape. Foods that normally foam and froth during cooking of any kind may foam and froth through this larger hole. This is part of the normal cooking process.

The Figure 1.0 shows the Auto lock and secondary safety device in the Zero pressure condition, the secondary safety device will be in downward condition, as the Auto lock which will swing in the lid handle and locked through the pin fixed, the foot of the Auto lock will not have any contact with the lid lug.

The Figure 2.0 shows the Auto lock and secondary safety device in pressure condition, the secondary safety device will be in upward condition, as the Auto lock which will swing in the lid handle and locked through the pin fixed, the foot of the Auto lock will come to contact with the lid lug as briefly explained in the figure.

The Figure 3.0 Shows The Secondary safety device and Auto Lock, the Secondary Safety device has a slit provide to release the excess steam.

This cooking appliance is equipped in addition with a safety device , the Quick release system is also present in this as the Auto Lock pin can be pressed with a spoon in pressure condition as the pressure steam is released ,

The advantageous exhibited by the product design:
1. Auto Lock is a device which locks the cooker under the pressure and does not allow the cooker to open in pressure condition.
2. Auto Lock can be used as the Visual pressure indicator, as the pin will be raised in pressurized condition and pin will be dropped in the non pressurized condition.
3. Auto Lock can be used for Quick release system, as the pressure can be released by pressing with the spoon for quick release of the excess steam.
4. Auto Lock has no springs and No external Mechanism, for locking and un locking the pressure cooker / vessel.
5. Auto Lock is the self balancing device for locking and unlocking the pressure cooker / vessel.
6. Secondary Safety device will be floating condition as it moves upward and downward by if self without any external force, it operates only with the internal pressure raises and lowers.
7. Secondary Safety device has a Slit which will release, if the Pressure Regulator Knob fails to function due to overload or blockage of the Pressure Regulator Vent Tube. If the pressure inside the pressure cooker rises above the normal level due to blockage of the Pressure Regulator Vent Tube.
8. The Auto lock will operate with the secondary safety device raised and lowers,
9. The Auto Lock cap is provided with the lid handle which will be in press fit , which is very easy for cleaning. it is detachable type Auto Lock Cap.
10. There is a sliding pin with is fixed to the Lid handle which will swing the Auto lock from being freely accessed, preventing it from being easily neutralized,
11. Locking of pressure cooker in lug with the Auto lock foot design.

The invention has been described with embodiments, examples and illustrations for purpose of understanding. All variations and modifications are within the scope of the invention.