WO2009005182A1

WO2009005182A1 - Pressure control and airtight device for pressure cooker

Info

Publication number: WO2009005182A1
Application number: PCT/KR2007/003636
Authority: WO
Inventors: Cha Sik Kim
Original assignee: Cha Sik Kim
Priority date: 2007-06-29
Filing date: 2007-07-27
Publication date: 2009-01-08
Also published as: KR100846863B1

Abstract

Disclosed is a pressure-control and airtight device for a pressure cooker. In the pressure cooker including a body and a lid to open or close an upper opening of the body, the lid is provided with a main valve to keep the lid in an airtight state. For this, if a housing member of the main valve is rotated under operation of a valve grip, a height of a fixing member of the main valve is changed to regulate a discharge pressure of steam for the removal of a predetermined pressure. Thereby, as a first airtight plate is automatically seated on a second airtight plate after the removal of a predetermined pressure, the main valve produces an airtight state between the first and second airtight plates, and consequently, keeps the lid in an airtight state.

Description

PRESSURE CONTROL AND AIRTIGHT DEVICE FOR PRESSURE

COOKER

[Technical Field]

The present invention relates to a pressure cooker, and more particularly, to a pressure-control and airtight device for a pressure cooker, which can easily regulate a cooking pressure inside the pressure cooker, and prevent the entrance of outside air into the pressure cooker even after completion of cooking while producing a low-pressure environment inside the pressure cooker, thereby enabling long-term storage of food received in the pressure cooker.

[Background Art]

Generally, a pressure cooker is a cooking appliance designed such that, when food is put into a body of a pressure cooker and cooked by heat applied to the bottom of the body in a state wherein the body is closed and sealed by a lid, the pressure cooker prevents leakage of steam to the outside, so as to cook the food by continuously keeping the food in a high-temperature and high-pressure state.

Although the pressure cooker conventionally has a valve for the discharge of steam, the valve simply has the functions of discharging steam to the outside or stopping the discharge of steam.

A problem of the conventional steam discharge valve for use in the pressure cooker is that it cannot fulfill a requirement in that the pressure of steam, to be discharged after food received in the pressure cooker is completely heated and cooked, has to be regulated according to the kind of food, the user's taste or the like.

Moreover, since the conventional steam discharge valve is left in an opened state after the discharge of steam, there are problems that outside air containing bacteria is introduced into the pressure cooker and air inside the pressure cooker cannot maintain a low pressure. This increases the probability of contamination of food inside the pressure cooker, resulting in deterioration in the storage stability of food. Therefore, there has been requested an improvement for the steam discharge valve.

[Disclosure]

[Technical Problem]

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a pressure-control and airtight device for a pressure container, which can regulate the discharge pressure of steam according to the user's taste, the kind of food, or the like, thereby increasing the use convenience of the pressure cooker.

It is another object of the present invention to provide a pressure-control and airtight device for a pressure cooker, which can prevent the entrance of outside air into the pressure cooker and keep air inside the pressure cooker at a low- pressure while storing food in the pressure cooker, thereby enhancing the storage stability of food.

[Technical Solution]

In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a pressure-control and airtight device for a pressure cooker including a body and a lid to open or close an upper opening of the body, comprising: a main valve installed at the lid to keep the lid in an airtight state, the main valve including: a housing member to be rotated under operation of a valve grip; a fixing member to be changed in height by rotation of the housing member so as to regulate a discharge pressure of steam for the removal of a predetermined pressure; and a first airtight plate to be automatically seated on a second airtight plate after the removal of a predetermined pressure to produce an airtight state therebetween and consequently, keep the lid in an airtight state.

Preferably, the body of the pressure cooker has a double structure consisting of an outer vessel and an inner vessel inserted into the outer vessel to have a predetermined space in the bottom of the body.

The main valve may further include: height-regulating slopes formed in the housing member and consisting of a plurality of teeth arranged to have a gradually increasing height for the regulation of a pressure; fixing pieces protruding from a fixing member disposed in the housing member to be engaged with corresponding ones of the teeth of the height-regulating slopes; a pressure member having a supporting disc to be pressed downward by a spring member disposed in the fixing member and a vertical bar protruding upward from the center of the supporting disc to be penetrated through the center of the fixing member, the vertical bar indicating a pressed state signal; a movable member disposed in the housing member, the pressure member being seated in the movable member to receive a pressure force from the spring member; an upper airtight member coupled to a lower end of the movable member and adapted to be moved in cooperation with vertical movements of the movable member; and a lower airtight member mounted to the lid below the upper airtight member and having a pressure discharge hole communicating with the interior of the pressure cooker.

The fixing pieces may protrude from opposite positions of an upper end of the fixing member, and the height-regulating slopes, by which the fixing pieces will be caught, may be located at opposite positions within a rotation operating range of the respective fixing pieces, and a height of the fixing member may gradually increase or decrease.

The movable member may be formed, at a lower end thereof, with inwardly protruding stepped portions, and the upper airtight member may be formed, at an upper end thereof, with an expanded portion to be inserted into and caught by the stepped portions. The first airtight plate may be stretched outward to have an upwardly recessed lower surface, and the second airtight plate to face the first airtight plate may be stretched outward to have a downwardly recessed upper surface, whereby an outer periphery of the first airtight plate is compressed onto a corresponding position of the upper surface of the second airtight plate to come into close contact with the corresponding position of the second airtight plate, to produce an airtight state therebetween.

A ring-shaped sealing member may be fitted into the rim of the lid to be coupled with the body, and may have an anti-suction protrusion protruding from an outer surface of the sealing member, the anti-suction protrusion preventing the sealing member from being constricted inward by a suction force caused by constriction of air inside the pressure cooker when the pressure cooker, which was heated and increased in pressure, is naturally cooled and kept in an airtight state.

The pressure-control and airtight device may further comprise: a sub valve to achieve automatic discharge of steam above a predetermined pressure exceeding the discharge pressure of steam regulated by the main valve. The sub valve may include: a body member fixed to the lid and internally defining an operating space communicating with the interior of the body, the body member being formed with an outlet hole to communicate the operating space with the outside of the lid; a rod member disposed in the operating space of the body member in a vertically movable manner; a cylinder member fitted around the rod member at a position near a lower end of the rod member, the cylinder member being adapted to slide along the operating space according to an internal pressure of the body; and an elastic member installed between the cylinder member and the body member to press the cylinder member into the body by a predetermined elastic force thereof.

The rod member may have a male screw portion formed around an upper end thereof, the upper end of the rod member being penetrated through an upper end of the body member such that the male screw portion is fastened with a female nut. [Advantageous Effects]

With a pressure-control and airtight device for a pressure cooker according to the present invention, differently from the prior art, the pressure of steam to be discharged can be easily regulated as the user manually turns a valve grip. This has the effect of allowing food to be cooked variously according to the user's taste, the kind of food, or the like.

Further, in the case where food is stored in the pressure cooker, according to the present invention, the entrance or escape of air into or out of the pressure cooker can be prevented by means of a main valve or sub valve used for the discharge of steam. Also, the main valve or sub valve can keep air inside the pressure cooker at a low pressure by allowing the inside high-temperature air to be cooled in a high-temperature state. This results in an improvement in the storage stability of food.

[Description of the Drawings]

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating the outer appearance of a pressure cooker according to a preferred embodiment of the present invention; FIG. 2 is a side sectional view of the pressure cooker taken along the line

"A-A" of FIG. 1;

FIG. 3 is an exploded perspective view of a main valve included in a pressure-control and airtight device for the pressure cooker according to an embodiment of the present invention; FIG. 4 is a side sectional view of the main valve shown in FIG. 3, prior to pressing a spring member of the main valve; FIG. 5 is a side sectional view of the main valve shown in FIG. 3, after pressing the spring member of the main valve;

FIG. 6 is a side sectional view illustrating a state wherein steam is discharged out of the pressure cooker by the main valve shown in FIG. 4; FIG. 7 is an exploded perspective view of a sub valve included in the pressure-control and airtight device for the pressure cooker according to an embodiment of the present invention;

FIG. 8 is a side sectional view of the sub valve shown in FIG. 7, prior to discharging steam out of the pressure cooker; FIG. 9 is a side sectional view illustrating a state wherein steam is discharged out of the pressure cooker by the sub valve shown in FIG. 7;

FIG. 10 is a perspective view illustrating the outer appearance of a pressure cooker according to another preferred embodiment of the present invention; and FIG. 11 is a side sectional view of the pressure cooker taken along the line

"B-B" of FIG. 10.

[Mode for Invention]

Now, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Referring to FIG. 1, a pressure cooker according to an embodiment of the present invention includes a body 1 having a double structure consisting of an outer vessel 3 and an inner vessel 5, and a Hd 6 to open or close an upper opening of the body 1.

In addition to the above described double structure, alternatively, the body 1 may have a single structure having only the outer vessel 3, or a triple or other multiple structures.

In the case of the double-structured body 1, a heat keeping space 2 is provided between the outer vessel 3 and the inner vessel 5. With the provision of the heat keeping space 2, heat transferred to the outer vessel 3 is able to be indirectly transferred to food by way of the heat keeping space 2, rather than being directly transferred to the food. This has the effect of achieving heat balance between upper and lower parts of the food received in the pressure cooker.

The heat keeping space 2 between the outer vessel 3 and the inner vessel 5 includes a bottom space defined in the bottom of the body 1 and a lateral space defined along a partial lateral wall of the body 1.

If heat is directly transferred from the outer vessel 3 to food, upper and lower parts of the food can achieve a heat balance because the bottom of the pressure cooker in contact with a heat source has a relatively high temperature, whereas the top of the pressure cooker at a distance from the heat source has a relatively low temperature.

However, in the pressure cooker according to the present invention, by virtue of the heat keeping space 2 between the outer vessel 3 and the inner vessel 5 of the body 1, air inside the heat keeping space 2 is heated by heat transferred from the bottom of the outer vessel 3, and in turn, the inner vessel 5 is uniformly heated by the heated air inside the heat keeping space 2, whereby food inside the pressure cooker can achieve a heat balance between upper and lower parts thereof, and consequently, food can be cooked efficiently.

Preferably, the outer vessel 3 is made of metals containing copper having an outstanding heat-transfer ability. With the use of the outer vessel 3 containing copper, a heat balance between the bottom and the top of the pressure cooker can be maintained more continuously. The lid 6 is provided with a main valve 10 to regulate the discharge pressure of steam via rotation of a valve grip 12, and a sub valve 60 to achieve automatic discharge of steam above a predetermined pressure.

The main valve 10 can regulate the pressure of steam to be discharged, and provide a cooking environment suitable for the kind of food or the user's taste. The sub valve 60 causes steam to be automatically discharged above a predetermined pressure exceeding the discharge pressure of steam regulated by the main valve 10, and prevents the explosion of the pressure cooker or other accidents.

It will be appreciated that the main valve 10 and the sub valve 60 are changeable variously in an installation position, configuration, etc. within the spirit of the present invention, so long as they are provided at the lid 6 to automatically discharge steam inside the pressure cooker.

A first handle 7 is coupled to the lid 6, and a second handle 8 is coupled to the body 1. The main valve 10 and the sub valve 60 are installed to the first handle 7.

To couple the first handle 7, a second bolt 86 is fastened to the first handle 7 and the lid 6 in a state wherein the first handle 7 comes into close contact with the lid 6.

To couple the second handle 8, a first bolt 82 is fastened to the second handle 8 and the body 1.

More specifically, the first bolt 82 is fastened to the outer vessel 3, and more particularly, to a mount 84 protruding outward from the outer vessel 3. The mount 4 receives therein a nut plate 95 having a female screw portion.

In a state wherein a head of the first bolt 82 is caught by the second handle 8, the first bolt 82 is sequentially penetrated through the outer vessel 3 and the nut plate 95 until it presses a lateral surface of the inner vessel 5.

As being pressed by the first bolt 82, the inner vessel 5 is installed at a fixed position inside the outer vessel 3.

A ring-shaped sealing member 90 is fitted into the rim of the lid 6 to be coupled with the body 1.

To install the sealing member 90, the sealing member 90 is stretched outward toward an inclined surface of the lid 6 and an inclined surface of the body 1. The sealing member 90 has outwardly protruding airtight protrusions 92 to prevent air inside and outside the sealing member 90 from moving to a connecting region of the lid 6 and the body 1.

An anti-suction protrusion 100 protrudes from an outer surface of the sealing member 90 coming into contact with an inner surface of the pressure cooker.

The inner surface of the pressure cooker has a groove, to allow the anti- suction protrusion 100 to be inserted into and caught by the groove.

It will be appreciated that the anti-suction protrusion 100 and the airtight protrusions 92 of the sealing member 90 have a triangular cross section, but the present invention is not limited thereto, and a variety of cross sectional shapes are applicable to the present invention. The anti-suction protrusion 100 may be formed only at an upper surface or lower surface of the sealing member 90. If necessary, the sealing member 90 may be provided with no anti-suction protrusion 100.

A body handle 9 is installed to the body 1 at the opposite side of the second handle 8. At least one of the second handle 8 and the body handle 9 is provided with the first bolt 82, the mount 84, and the nut plate 95, so as to be coupled with the inner vessel 5.

The main valve 10 includes a housing member 11 having the valve grip 12 protruded from one side thereof and height-regulating slopes 16 formed therein, the height-regulating slopes 16 consisting of a plurality of teeth arranged to have a gradually increasing height.

The main valve 10 further includes a fixing member 20 disposed in the housing member 11. The fixing member 20 has fixing pieces 22 protruding upward from an upper end thereof to be engaged with corresponding ones of the teeth of the height-regulating slopes 16. The main valve 10 further includes a spring member 28 disposed in the fixing member 20, and a pressure member 37 disposed in the spring member 28. The pressure member 37 has a circular supporting disc 33 to be pressed downward by the spring member 28, and a vertical bar 34 protruding upward from the center of the supporting disc 33 to be penetrated through the center of the fixing member 20, the vertical bar 34 indicating a pressed state signal.

The vertical bar 34 has a hollow structure, to prevent the risk of deformation, etc. upon injection molding and also, to reduce material costs.

The shape of the pressure member 37 may be changed in various manners within the spirit of the present invention, so long as the supporting disc 33 is provided perpendicular to the vertical bar 34 so as to support the spring member 28.

The main valve 10 further includes a movable member 30 in which the pressure member 37 is seated such that a pressure force from the spring member 28 is transmitted to the movable member 30. The movable member 30 is movable vertically inside the housing member 11.

The pressure member 37 also has a stepped portion between the vertical bar 34 and the supporting disc 33, the stepped portion defining therein a space. The movable member 30 has an insertion protrusion 31 formed at an inner surface thereof to be inserted into the space of the stepped portion. The moving member 30 also has a ring-shaped fixing groove formed in the inner surface thereof to allow the supporting disc 33 to be inserted into and seated in the fixing groove.

With the above described configuration, the pressure member 37 is coupled with the movable member 30.

The spring member 28 to elastically support the fixing member 20 is installed between the fixing member 20 and the pressure member 37.

The vertical bar 34 protrudes out of the housing member 11 to be seen by the user, so as to indicate a pressed state signal of the pressure cooker.

The main valve 10 further includes an upper airtight member 40 coupled to a lower end of the movable member 30 and adapted to be moved vertically in cooperation with vertical movements of the movable member 30, and a lower airtight member 50 mounted to the lid 6 below the upper airtight member 40 and having a pressure discharge hole 54 communicating with the interior of the pressure cooker.

The fixing pieces 22 protrude from opposite positions of the upper end of the fixing member 20. The height-regulating slopes 16, by which the fixing pieces 22 will be caught, are located at opposite positions within a rotation operating range of the respective fixing pieces 22.

For example, the fixing pieces 22 are located at opposite left and right positions, and the height-regulating slopes 16 are arranged at opposite left and right arcuate sections in which the fixing pieces 22 are rotated. The height of the fixing member 20 gradually increases or decreases such that both the fixing pieces 22 have the same height as each other.

The teeth of the height-regulating slopes 16 have a triangular cross section. The fixing pieces 22 to be caught by the height-regulating slopes 16 have a wedge shape.

The housing member 11 having the height-regulating slopes 16 has a cylindrical upper body 14. The valve grip 12 is provided at an upper end of the upper body 14 to allow the user to turn the upper body 14. The upper body 14 is formed, at a lower end thereof, with inwardly protruding supporting pieces 18 to support a lower end of the movable member 30.

The upper body 14 is also formed, at the lower end thereof, with lower hooks 39. The lid 6 is formed, at opposite positions thereof, with arcuate rotation- guiding slots 59 to allow the lower hooks 39 to be inserted into and be rotated along the guiding slots 59.

The length of the rotation guiding slots 59 is determined according to a rotation angle of the housing member 11. A first coupling hole 58 is formed in the center of both the rotation-guiding slots 59 for the fixation of the lower airtight member 50. The fixing member 20 has a cylindrical fixing body 24. The fixing pieces

22 protrude from an upper end of the fixing body 24, and lateral pieces 26 protrude downward from a lower end of the fixing body 24.

The spring member 28 is provided between the fixing member 20 and the pressure member 37. It will be appreciated that other various elastic members except for the spring member 28 may be used within the spirit of the present invention so long as the elastic members can regulate a pressure force that is caused by vertical movements of the fixing member 20 and applied to the pressure member 37. The movable member 30, on which the supporting disc 33 of the pressure member 37 will be seated, includes a cylindrical movable body 32 having an opened upper end. The pressure member 37 is mounted in the center of the movable body 32 such that the vertical bar 34 protrudes out of the movable body 32.

The upper end of the movable body 32 is inwardly bent to define a circumferential stepped portion 36. The movable body 32 is formed, in an inner surface thereof at a position below the stepped portion 36, with vertically extending guide grooves 38 such that the lateral pieces 26 are inserted into the guide grooves 38 and guided in vertical movements thereof.

As the lateral pieces 26 of the fixing member 20 are caught by the guide grooves 38 of the movable member 30, the fixing member 20 is restricted in rotation, and is movable only vertically.

The movable member 30 and the housing member 11 are formed, at their facing surfaces, with guide protrusions and rails, to restrict rotation of the movable member 30 while allowing only vertical movements of the movable member 30. The movable member 30 also has inwardly protruding arcuate stepped portions 35 formed by bending a lower end thereof at a position below the center of the movable member 30 to be coupled with the pressure member 37, the arcuate stepped portions 35 defining a hollow space therebetween. The upper airtight member 40 is formed, at an upper end thereof, with an expanded portion 42 to be inserted into and caught by the stepped portions 35.

The upper airtight member 40 has a first airtight plate 44 provided at a lower end thereof. The lower airtight member 50 has a second airtight plate 52 corresponding to the first airtight plate 44. The second airtight plate 52 has a groove 56 formed along an outer circumferential surface thereof at a predetermined lower position to be coupled with the edge of the first coupling hole 58.

The first airtight plate 44 is stretched outward to have an upwardly recessed lower surface. The second airtight plate 52 to face the first airtight plate 44 is stretched outward to have a downwardly recessed upper surface. An outer periphery of the first airtight plate 44 is compressed onto a corresponding position of the upper surface of the second airtight plate 52 to come into close contact with the corresponding position of the second airtight plate 52, to produce an airtight state therebetween.

With the above described configurations of the first and second airtight plates 44 and 52, after the housing member 11 is rotated under operation of the valve grip 12 to change the height of the fixing member 20 so as to regulate the discharge pressure of steam for the removal of a predetermined pressure, the first airtight plate 44 is automatically seated on the second airtight plate 52, to create an airtight space therebetween. Although the upper and lower airtight members 40 and 50 are formed by use of rubber, silicon, or the like, the present invention is not limited thereto, and any other elastic materials may be used to form the upper and lower airtight members 40 and 50.

The sub valve 60 includes a body member 61 configured to be fixed to the lid 6 and internally defining an operating space communicating with the interior of the body 1, the body member 61 being formed with an outlet hole 65 to communicate the operating space with the outside of the lid 6, a rod member 74 disposed in the operating space of the body member 61 in a vertically movable manner, a cylinder member 70 fitted around the rod member 74 at a position near a lower end of the rod member 74, the cylinder member 70 being adapted to slide along the operating space according to an internal pressure of the body 1, and an elastic member 72 installed between the cylinder member 70 and the body member 61 to press the cylinder member 70 into the body 1 by a predetermined elastic force thereof. The rod member 74 has a male screw portion 78 formed around an upper end thereof. The upper end of the rod member 74 is penetrated through an upper end of the body member 61 such that the male screw portion 78 is fastened with a female nut 67. The body member 61 has a cylindrical valve body 62, and the cylindrical valve body 62 is perforated in an upper surface thereof, with an upper through-hole 66 to allow the penetration of the male screw portion 78.

The body member 61 also has a flange 63 circumferentially protruding from an outer circumferential surface thereof to be caught and supported by an upper surface of the lid 6. The outlet hole 65 is located above the flange 63, and an auxiliary inlet hole 64 is formed in the body member 61 below the flange 63.

The body member 61 is formed with a male screw portion 68 below the flange 63. The sub valve 60 further includes a fixing nut 79 to be fastened with the male screw portion 68. The male screw portion 68 is penetrated through a second coupling hole 73 perforated in the lid 6 to protrude downward into the pressure cooker. As the fixing nut 79 is fastened with the male screw portion 68, the sub valve 60 is completely fixed to the lid 6.

The elastic member 72 in the form of a coil spring is disposed in the body member 61. The rod member 74, around which the cylinder member 70 was fitted, is penetrated through the interior of the elastic member 72.

With this arrangement, the cylinder member 70 is pressed inward of the pressure cooker by an elastic force of the elastic member 72.

The cylinder member 70 may be made of various materials such as cork, rubber, silicon, or the like, to be moved by the internal pressure of the pressure cooker.

The cylinder member 70 is kept at a fixed position as it is caught by a head portion 76 of the rod member 74.

Meanwhile, to allow the sub valve 60 to be installed on the lid 6 in an airtight state, an O-ring is mounted at an upper surface of the flange 63 of the sub valve 60.

The main valve 10 and the sub valve 60 having the above described configurations constitute a pressure-control and airtight device for the pressure cooker according to an embodiment of the present invention,

Now, the operation of the pressure-control and airtight device for the pressure cooker, which has the above described configuration according to the embodiment of the present invention, will be described.

If the bottom of the body 1 is heated after the lid 6 is coupled to the upper opening of the body 1, the heat keeping space 2 inside the outer vessel 3 is heated, causing upper and lower portions of the inner vessel 5, in contact with the heat keeping space 2, to be uniformly heated.

Meanwhile, as the lid 6 of the pressure cooker is tightly closed, the airtight protrusions 92 of the sealing member 90 are stretched upward and downward to come into contact with the inner inclined surfaces of the lid 6 and the inner vessel 5, thereby producing an airtight state between the lid 6 and the inner vessel 5.

If the valve grip 12 is manually turned to regulate the elastic force of the spring member 28, the regulated elastic force is transmitted to the movable member

30 through the pressure member 37, so as to press down the movable member 30. In this case, the upper airtight member 40 connected with the movable member 30 regulates the pressing degree of the movable member 30.

Since the cylinder member 70 of the sub valve 60 is also pressed downward by the elastic member 72, the sub valve 60 prevents steam inside the pressure cooker from being discharged to the outside below a predetermined pressure. The pressure of steam to be discharged through the main valve 10 can be regulated by manually turning the valve grip 12.

If the valve grip 12 is turned, the fixing pieces 22, which are caught by the height-regulating slopes 16 having a gradually increasing or decreasing height, are moved upward or downward. Thereby, as the fixing member 20 is moved upward or downward, the spring member 28 is compressed beyond a predetermined degree or released from the compressed state.

In this way, it is possible to regulate the compression degree of the upper airtight member 40 with respect to the lower airtight member 50. When the fixing member 20 is moved close to the housing member 11 so as not to compress the spring member 28 beyond a predetermined value as shown in FIG. 4, the upper airtight member 40 is lifted upward by the pressure of steam inside the pressure cooker as shown in FIG. 6, thereby enabling the exhaust of air to the outside through an outlet hole 80.

When the fixing member 20 is moved away from the housing member 11 to compress the spring member 28 beyond the predetermined value as shown in FIG. 5, the compressed force of the spring member 28 is larger than the pressure of steam inside the pressure cooker. Thereby, the main valve 10 prevents the steam or air inside the pressure cooker from being discharged to the outside, and also prevents outside air from being introduced into the pressure cooker.

The pressure of steam discharged through the main valve 10 can be regulated by regulating the compressed degree of the spring member 28 by regulating the rotation degree of the valve grip 12. If the pressure of steam exceeds a predetermined value due to abnormal operation of the main valve 10, the cylinder member 70 of the sub valve 60 is moved upward by the pressure of steam, in order to prevent damage to the pressure cooker or any other accidents due to the excessively high pressure of steam beyond the predetermined value. Accordingly, the air inside the pressure cooker is moved upward through a lower through-hole of the valve body 62 and the auxiliary inlet hole 64, to thereby be discharged through the outlet hole 65 perforated in the lateral surface of the valve body 62.

The auxiliary inlet hole 64 serves as an auxiliary passage for the discharge of air inside the pressure cooker when the lower through-hole of the valve body 62 is clogged with impurities,.

With the use of the main valve 10 and the sub valve 60, the pressure of steam inside the pressure cooker can be regulated according to the user's taste, the kind of food, etc. Also, when the pressure cooker is used to store food therein after completion of cooking, the pressure cooker is kept in an airtight state by the main valve 10 and the sub valve 60.

By keeping the interior of the pressure cooker in an airtight state, the food inside the pressure cooker can be kept in a sterilized low-pressure state without the risk of invasion of outside air containing bacteria, resulting in an improvement in the storage stability of food in the pressure cooker.

FIG. 10 is a perspective view illustrating the outer appearance of a pressure cooker according to another preferred embodiment of the present invention. FIG. 11 is a side sectional view of the pressure cooker taken along the line "B-B" of FIG. 10.

For the convenience of description, the same reference numerals will be used to designate the same constituent elements as those of the previously described embodiment, and a detailed description thereof will be omitted.

As shown in FIGS. 10 and 11, a body 110 of the pressure cooker according to the present embodiment has a single structure, and a mount bracket

115 is fixed to a lateral surface of the body 110 by welding, etc. The mount bracket 115 is protruded outward from the body 110 for the fixing of the second handle 8.

The nut plate 95 having a female screw portion is installed in the mount bracket 115. The first bolt 82, which has a head caught by the second handle 8, is inserted into and fixed by the nut plate 95.

The body handle 9 is installed at the opposite side of the second handle 8. At least one of the second handle 8 and the body handle 9 is fixed by means of the first bolt 82, the mount bracket 115, and the nut plate 95. Even in the case of the pressure cooker having the single structured body 110, the main valve 10 and the sub valve 60 of the previously described embodiment are installed to perform the same operations.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

For example, the pressure-control and airtight device according to the embodiments of the present invention may be used in various pressure cookers having a single structure or triple or other multiple structure except for the above described double structure.

Further, although the pressure-control and airtight device for use in the pressure cooker has been described, the above description is given by an example, and the pressure-control and airtight device may be applied to other cooking appliances other than the pressure cooker.

Accordingly, the protective range of the present invention should be defined by the following claims.

Claims

[CLAIMS]

[Claim 1] A pressure-control and airtight device for a pressure cooker including a body and a lid to open or close an upper opening of the body, comprising: a main valve installed at the lid to keep the lid in an airtight state, the main valve including: a housing member to be rotated under operation of a valve grip; a fixing member to be changed in height by rotation of the housing member so as to regulate a discharge pressure of steam for the removal of a predetermined pressure; and a first airtight plate to be automatically seated on a second airtight plate after the removal of a predetermined pressure to produce an airtight state therebetween and consequently, keep the lid in an airtight state.

[Claim 2] The device according to claim 1, wherein the body of the pressure cooker has a double structure consisting of an outer vessel and an inner vessel inserted into the outer vessel to have a predetermined space in the bottom of the body.

[Claim 3] The device according to claim 1 or 2, wherein the main valve further includes: height-regulating slopes formed in the housing member and consisting of a plurality of teeth arranged to have a gradually increasing height for the regulation of a pressure; fixing pieces protruding from a fixing member disposed in the housing member to be engaged with corresponding ones of the teeth of the height-regulating slopes; a pressure member having a supporting disc to be pressed downward by a spring member disposed in the fixing member and a vertical bar protruding upward from the center of the supporting disc to be penetrated through the center of the fixing member, the vertical bar indicating a pressed state signal; a movable member disposed in the housing member, the pressure member being seated in the movable member to receive a pressure force from the spring member; an upper airtight member coupled to a lower end of the movable member and adapted to be moved in cooperation with vertical movements of the movable member; and a lower airtight member mounted to the lid below the upper airtight member and having a pressure discharge hole communicating with the interior of the pressure cooker.

[Claim 4] The device according to claim 3, wherein the fixing pieces protrude from opposite positions of an upper end of the fixing member, and the height-regulating slopes, by which the fixing pieces will be caught, are located at opposite positions within a rotation operating range of the respective fixing pieces, and wherein a height of the fixing member gradually increases or decreases.

[Claim 5] The device according to claim 3, wherein the movable member is formed, at a lower end thereof, with inwardly protruding stepped portions, and the upper airtight member is formed, at an upper end thereof, with an expanded portion to be inserted into and caught by the stepped portions.

[Claim 6] The device according to claim 1 or 2, wherein the first airtight plate is stretched outward to have an upwardly recessed lower surface, and the second airtight plate to face the first airtight plate is stretched outward to have a downwardly recessed upper surface, whereby an outer periphery of the first airtight plate is compressed onto a corresponding position of the upper surface of the second airtight plate to come into close contact with the corresponding position of the second airtight plate, to produce an airtight state therebetween.

[Claim 7] The device according to claim 1 or 2, wherein a ring-shaped sealing member is fitted into the rim of the lid to be coupled with the body, and has an anti- suction protrusion protruding from an outer surface of the sealing member, the anti- suction protrusion preventing the sealing member from being constricted inward by a suction force caused by constriction of air inside the pressure cooker when the pressure cooker, which was heated and increased in pressure, is naturally cooled and kept in an airtight state.

[Claim 8] The device according to claim 1 or 2, further comprising: a sub valve to achieve automatic discharge of steam above a predetermined pressure exceeding the discharge pressure of steam regulated by the main valve, wherein the sub valve includes: a body member fixed to the lid and internally defining an operating space communicating with the interior of the body, the body member being formed with an outlet hole to communicate the operating space with the outside of the lid; a rod member disposed in the operating space of the body member in a vertically movable manner; a cylinder member fitted around the rod member at a position near a lower end of the rod member, the cylinder member being adapted to slide along the operating space according to an internal pressure of the body; and an elastic member installed between the cylinder member and the body member to press the cylinder member into the body by a predetermined elastic force thereof.

[Claim 9] The device according to claim 8, wherein the rod member has a male screw portion formed around an upper end thereof, the upper end of the rod member being penetrated through an upper end of the body member such that the male screw portion is fastened with a female nut.