Title of Invention

"POT FOR AN INDUCTION HEATING COOKING APPLIANCE AND METHOD FOR FABRICATING THE SAME"

Abstract Pot for an induction heating cooking appliance, and method for fabricating the same, the pot including an inner pot having a plurality of projections from a part of an outside surface, and a cap of a magnetic metal pressed down onto at least a part of an outside surface of the inner pot, having holes with the projections received therein, and the method including the steps of (a) forming an inner pot having an inside space, and an opened top, (b) forming a cap having a form fit to at least a part of the inner pot, and a plurality of holes, (c) preheating the inner pot and the cap to a preset temperature, and (d) pressing down the inner pot and the cap at a high temperature, together.
Full Text Field of the Invention
The present invention relates to a pot for an induction heating cooking appliance, and a method for fabricating the same.
Background of the Related Art
Recently many kinds of induction heating cooking appliances are developed. The induction heating cooking appliance cooks food held in the pot with heat generated by resistance of the pot against an eddy current induced by a magnetic field formed in the vicinity of a coil having a current provided thereto. FIG. 1 illustrates a related art induction heating cooking appliance, referring to which the induction heating cooking appliance will be described.
Referring to FIG. 1, there is a case 1 provided with an inside space, and an opened top. There is a cover 2 hinged to the case 1 for closing the opened top of the case 1. There is a pot 3 in the inside space of the case 1, which is able to be mounted/dismounted in the inside space of the case 1 through the opened top of the case 1.
Referring to FIG. 2, in general, the pot 3 is fabricated by drawing a clad plate of a stainless plate 3a and an aluminum plate 3b. The stainless steel plate 3a forms an exterior of the pot 3, and the aluminum plate 3b forms an interior of the pot 3.
There is a coil4 in the inside space of the case 1, at positions opposite to an underside and a lower part of aside of the pot 3 when the pot 3 is mounted. There is a first heater 5 over the coil 4, substantially at a position to surround an upper outside circumferential surface of 5 the pot 3 when the pot 3 is mounted in the case 1. The cover 2 is provided with a second heater 6 at a position opposite to the opened top.
The cover 2 is provided with a valve 8 for relieving steam from an inside to an outside of the pot 3 during or after cooking. There are sensors 7 in the cover 2 and the inside space of the case 1 for measuring an inside temperature of the pot 3.
When a current is provided to the coil 4 of the induction heating cooking appliance, lines of magnetic force are formed in the vicinity of the coil 4. If the pot 3 is in the case 1, the lines of magnetic force transmit the pot 3. When the lines of magnetic force transmit the pot 3, there are lots of eddy currents generated around the lines of the magnetic force, and the eddy currents generate heat owing to resistance of a material of the pot 3, resulting to heat the pot 3 itself. The heat generated at the pot 3 itself heats the food held in the pot 3. Meanwhile, the first, and second heaters 5 and 6 heat the food complementarity, or keeps the food warm after the cooking is finished.
However, the related art induction heating cooking appliance has the following problems.
First, for fabrication of the pot, it is required to clad the stateliness steel plate and the aluminum plate, and draw the clad plate, that requires many fabrication process and a high production cost.
Second, the stainless steel on the entire exterior of the pot requires much material cost and causes the pot heavy.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a pot for an induction heating cooking appliance, and a method for fabricating the same that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a pot for an induction heating cooking appliance, which can be fabricated simply, and a method for fabricating the same.
Other object of the present invention is to provide a pot for an induction heating cooking appliance, which has light weight, and a method for fabricating the same.
Another object of the present invention is to provide a pot for an induction heating 10 cooking appliance, which has a fine view, and a method for fabricating the same.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, the pot for an induction heating cooking appliance includes an inner pot having a plurality of projections from apart of an outside surface, and a cap of a magnetic metal pressed down onto at least a part of an outside surface of the inner pot, having holes with the projections received therein.
The cap is provided to a bottom surface of the inner pot, or a lower circumferential surface of the inner pot. Or, the cap is provided to an entire outside surface of the inner pot.
The inner pot may be formed of aluminum, and the cap may be formed of stainless steel.
In other aspect of the present invention, there is provided an induction heating cooking appliance including a case having an inside space and an opened top, a cover hinged to the case for closing the opened top of the case, a pot having an inner pot with a plurality of projections from apart of an outside surface, and a cap of a magnetic metal pressed down onto at least a part of the outside surface of the inner pot, with holes with the projections received therein, for mounting or dismounting on/from the case, and a coil in the case at a position opposite to the cap when the pot is mounted thereon.
The induction heating cooking appliance further includes heaters provided to one, or more than one of the case and the cover.
The induction heating cooking appliance further includes a valve provided to the cover for relieving steam from the inside to an outside of the inner pot.
In another aspect of the present invention, there is provided a method for fabricating a pot for an induction heating cooking appliance including the steps of (a) forming an inner pot having an inside space, and an opened top, (b) forming a cap having a form fit to at least a part of the inner pot, and a plurality of holes, (c) preheating the inner pot and the cap to a preset temperature, and (d) pressing down the inner pot and the cap at a high temperature, together.
The (a) step includes the step of drawing a first plate.
The (b) step includes the steps of perforating a second plate to form the holes, and subjecting the second plate having the holes formed therein to plastic deformation.
The (d) step is carried out until a portion of material of the inner pot is pushed into the holes in the cap, and stuffs the holes, fully.
It is to be understood that both the foregoing description and the following detailed description of the present invention are exemplary and explanatory and are intended to 25 provide further explanation of the invention claimed.
BRIEF DESCRITPION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings;
FIG.l illustrates a section of a related art induction heating cooking appliance;
FIG. 2 illustrates a section of a pot and a coil of the induction heating cooking appliance in FIG. 1;
FIG. 3 illustrates a perspective view of a pot of an induction heating cooking appliance in accordance with a preferred embodiment of the present invention;
FIG. 4 illustrates an enlarged section of a part of the pot in FIG. 3;
FIGS. 5A -5D illustrate sections each showing the steps of a process for fabricating the pot in FIG. 3, wherein
FIG. 5 A illustrates a section of a finished inner pot„
FIG. 5B illustrates a section of a finished cap,
FIG. 5C illustrates a section of the inner pot and the cap aligned oppositely for preheating, and
FIG. 5D illustrates a section of a finished pot in accordance with a preferred embodiment of the present invention, fabricated by pressing the inner pot and the cap at high temperature, and high pressure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In describing the embodiments, same parts will be given the same names and reference symbols, and repetitive description of which will be omitted.
A general system of an induction heating cooking appliance of the present invention is identical to one described with reference to FIG. 1. Therefore, the general system description of the induction heating cooking appliance will be omitted, and a pot in the induction heating cooking appliance of the present invention will be described.
Referring to FIG. 3, the pot 100 includes an inner pot 110, and a cap 120 pressed on an outside surface of the inner pot 110.
The inner cap 110 is formed of a metal with good heat conductivity, such as aluminum. The inner pot 110 has a cooking space 101 for holding food therein and cooking the food with heat. The inner pot 110 has an opened top for a user to put food into the cooking space 101, or take out the food therefrom.
The inner pot 110 is substantially cylindrical, and has a flat bottom, and an outside circumferential surface and a bottom surface connected with a round surface.
There is a flange 115 at a top circumference of the inner pot 110. The flange 115, not only limits an inserted depth of the inner pot 110 when the inner pot 110 is put into a case 1 of an induction heating cooking appliance of a kind shown in FIG. 1, but also enhances air tightness between the inner pot 110 and the cover 2.
Referring to FIG. 4, there are a plurality of projections 111 on a part of an outside surface of the inner pot 110. The projections 111 are respectively stuffed in a plurality of holes 121 in the cap 120, to enhance a binding force of the inner pot 110 and the cap 120.
In the meantime, the cap 120 is formed of a magnetic metal, preferably of a magnetic metal with a high electric resistance. Once the cap 120 is formed of such a material, the pot 100 can have much resistive heat when the magnetic field transmits the pot 100 to form the eddy currents therein. As a material of the cap 120 using such a property, there is, for example, stainless steel.
The cap 120 is pressed, and attached to a part of the inner pot 110 for making the induction heating possible. To do this, the cap 120 has an inside surface identical to the part of the outside surface of the inner pot 110. It is preferable that the cap 120 is provided to a bottom surface of the inner pot 110, and more preferably, not only to the bottom surface of the inner pot 110, but also to a lower circumferential surface of the inner pot 110. The cap 120 provided thus is positioned opposite to the coil 4 when the pot 100 is mounted in an induction heating cooking appliance of a kind as shown in FIG. 1.
In the meantime, the cap 120 is not limited to above structure, but may be provided to an entire outside surface of the inner pot 110, when the inside surface of the cap 120 an identical form with the entire outside surface of the inner pot 110.
The cap 120 has a plurality of holes 121, each of which is, for an example, circular as shown in FIG. 3. However, the hole 121 is not limited to the circular form, but may have a variety of forms, such as triangular, square, polygonal, like a star, or elliptical. The variety of forms of the hole 121 makes an outside appearance of the pot 100 to have a fine view. By changing the form of the hole 121 in fabrication of the cap 120, an exterior design of the pot 100 can be changed, easily.
In the meantime, the projections 111 on the inner pot 110 are joined with the holes 121 in the cap 120, respectively. Because of a structure in which the projections 111 on the inner pot 110 are respectively stuffed in, and fastened to the holes 121 of the cap 120, the inner pot 110 and the cap 120 can maintain a rigidly attached state
However, in the pot 100 of the present invention, it is not true that the projections 111 are formed artificially in the step of fabricating the inner pot 110, and inserted in the holes 121 of the cap 120. In more detail, in fabrication of the pot 100 of the present invention, though the inner pot 110 and the cap 120 are fabricated separately, and put together, the projections 111 are not formed separately in the fabrication of the inner pot 110.
However, the projection 111 is formed in a process in which, when the inner pot 110 and the cap 120 fabricated separately are put together under high temperature and high pressure, a poftion of material of the inner pot 110 is pushed into the hole 121 of the cap 120 by the high pressure, and stuffs the hole 121 completely, similar to riveting.
In the meantime, the projections are projected from the bottom surface and the outside circumferential surface of the inner pot 110. Therefore, the difference of projection directions of the projections 111 assures positive attachment of the cap 120 to the inner pot 110, enough to prevent separation by an external force.
Thus, the pot 100 is fabricated by above unique process of putting the inner pot 110 and the cap 120 together, which will be described in more detail with reference to FIGS. 5A - 5D.
The process includes four steps of the steps of forming the inner pot 110 and the cap 120 separately, a step for preheating the inner pot 110 and the cap 120, and putting the inner pot 110 and the cap 120 together.
Referring to FIG. 5A, the inner pot 110 is formed to have a cooking space therein and an opened top. The inner pot 110 is formed by drawing a first plate, for an example, an aluminum plate. In this instance, if required, the flange 115 is also formed, with an edge of the flange 115 cut to a desired form.
Then, referring to FIG. 5B, the cap 120 is formed to fit to at least part of an outside surface of the inner pot 110. The cap 120 is formed of a magnetic metal, moreover, a magnetic metal with a high electric resistance, such as stainless steel.
A flat second plate of stainless steel is perforated, to form the holes 121, and subjected to plastic deformation, such as by pressing, to form the cap 120.
Once fabrication of the inner pot 110 and the cap 120 is finished, as shown in FIG. 5C, the cap 120 is aligned under the inner pot 110, and preheats to a preset temperature, such as a temperature at which pressing is easy.
Upon finishing preheating of the inner pot 110 and the cap 120, the inner pot 110 and the cap 120 are pressed under a high temperature. Then, a portion of the material of the inner pot 110 at the outside surface thereof is pushed into the holes 121 in the cap 120, to form the projections 111, until the projections 111 respectively stuff the holes 121 fully as shown in FIG. 5D. If the inner pot 110 and the cap 120 are cooled down in a state the holes 121 in the cap 120 are stuffed with the projections 111 of the inner pot 110, the inner pot 110 and the cap 120 become one complete pot 100 having a shape as shown in FIG. 3.
Once the inner pot 110 and the cap 120 are put together by above method, the inner pot 110 and the cap 120 are not separated because an interface of the inner pot 110 and the cap 120 are bonded to each other under the high temperature and pressure. Moreover, since a state is maintained, in which the projections 111 of the inner pot 110 are stuffed in the cap 120, the binding force between the inner pot 110 and the cap 120 are enhanced. Furthermore, the different directions of the projections 111 assure positive attachment of the cap 120, enough to prevent separation of the cap 120 from the inner pot 110 by an external force.
The pot 100 fabricated thus is used in an induction heating cooking appliance of a kind as shown in FIG. 1. When a current is provided to the coil 4 at a time the induction heating cooking appliance is started to operate, a magnetic field formed in the vicinity of the coil 4 passes through a part of the pot 100 having the cap 120 attached thereto. Then, eddy currents are formed in the cap 120, to generate resistive heat as the cap 120 has a high electric resistance. The resistive heat generated at the cap 120 is transmitted to the inner pot 110 having a high heat conductivity, and heats the food held in the inner pot 110.
In the meantime, if the induction heating cooking appliance further includes the first heater 5 and the second heater 6, the first and second heaters 5 and 6 heat the food supplementally, to help the cooking. After finish of the cooking, the first and second heaters 5 and 6 keep the food warm.
Meanwhile, when a valve 8 is provided to the cover 2, the valve 8 relieves steam produced from the food during the cooking from an inside to an outside of the inner pot 110, for preventing an inside pressure of the induction heating cooking appliance from rising, thereby preventing accident caused by negligence of safety from taking place.
The pot in an induction heating cooking appliance, and method for fabricating the same have the following advantages.
First, the fabrication by pressing a separately fabricated cap onto an inner pot without the complicated cladding and forming permits fabrication of the pot easier than the related art.
Second, the provision of the cap only to a part required for induction heating permits to reduce a weight in comparison to the related art. Moreover, the reduced amount of expensive stainless steel used in the pot permits to reduce a production cost.
Third, the availability of various forms of the holes can provide a fine view, and permits easy design change.
Fourth, no separate supplementary material is required for bonding the cap to the inner pot because a portion of the inner pot is pushed into the holes in the cap under high pressure and temperature. Moreover, the inner pot and the cap are put together very rigidly by the projections and the holes.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.




We Claim:
1. A pot (100) for an induction heating cooking appliance comprising:
an inner pot (110) having a plurality of projections (111) on lower part of an outside surface; and
a cap (120) of a magnetic metal pressed down at least onto a part of an outside surface of the inner pot (110), having holes (121) with the projections (111) received therein.
2. The pot (100) as claimed in claim 1, wherein the cap (120) is provided to a bottom surface of the inner pot (110).
3. The pot (100) as claimed in claim 1 or 2, wherein the cap (120) is provided to a lower circumferential surface of the inner pot (110).
4. The pot (100) as claimed in claim 1, wherein the cap (120) is provided to an entire outside surface of the inner pot (110).
5. The pot (100) as claimed in claim 1, wherein the inner pot (110) is formed of aluminum.
6. The pot (100) as claimed in claim 1, wherein the cap (120) is formed of stainless steel.
7. A method for fabricating a pot (100) for an induction heating cooking appliance as claimed in claim 1, the method comprising the steps of:

(a) forming an inner plate having an inside space, and an opened top;
(b) forming a cap (120) having a form fit to at least a part of the inner pot (110), and a plurality of holes (121);
(c) preheating the inner pot (110) and the cap (120) to a preset temperature; and
(d) pressing down the inner pot (110) and the cap (120) at a high temperature, together.
8. The method as claimed in claim 7, wherein the (a) step includes the step of drawing a first plate.
9. The method as claimed in claim 7, wherein the (b) step includes the steps of; perforating a second plate to form the holes (121); and subjecting the second plate having the holes (121) formed therein to plastic deformation.
10. The method as claimed in claim 7, wherein the (d) step is carried out until a portion of material of the inner pot (110) is pushed into the holes (121) in the cap (120), and stuffs the holes (121), fully.
11. A pot (100) for an induction heating cooking appliance and method for fabricating the same as substantially herein described with reference to the text description and the drawing Figure no. 3, Figure no.4 and Figure no. 5a to 5d.

Documents:

51-del-2004-abstract.pdf

51-del-2004-claims.pdf

51-DEL-2004-Correspondence-Others-(09-08-2010).pdf

51-del-2004-correspondence-others.pdf

51-del-2004-correspondence-po.pdf

51-del-2004-description (complete).pdf

51-del-2004-drawings.pdf

51-DEL-2004-Form-1-(09-08-2010).pdf

51-del-2004-form-1.pdf

51-del-2004-form-19.pdf

51-del-2004-form-2.pdf

51-del-2004-form-26.pdf

51-del-2004-form-3.pdf

51-del-2004-form-5.pdf


Patent Number 242707
Indian Patent Application Number 51/DEL/2004
PG Journal Number 37/2010
Publication Date 10-Sep-2010
Grant Date 06-Sep-2010
Date of Filing 12-Jan-2004
Name of Patentee LG ELECTRONICS INC.
Applicant Address 20, YOIDO-DONG, YOUNGDUNGPO-DU, SEOUL, KOREA
Inventors:
# Inventor's Name Inventor's Address
1 LEE, KI SEONG 210-906, SUNGWON APT.,22, NAMYANG-DONG, CHANGWON-SI, GYEONGSANGNAM-DO, REPUBLIC OF KOREA
2 JEONG, SOON GY 103-1705, DAEDONG APT.,DAEBANG-DONG, CHANGWON-SI, GYEONGSANGNAM-DO, REPUBLIC OF KOREA
PCT International Classification Number H05B 6/10
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 P 2003-0009199 2003-02-13 Republic of Korea