ELECTRIC COOKER
Technical Field
The present invention relates to the field of cooking equipment and in particular to an electric cooker.
Background Art
Electric cookers for steaming rice, such as electric rice cookers of the prior art, are equipped with an internal pot, which is in turn equipped with a steamer. Rice is placed within the steamer and water is contained within the internal pot. By heating the internal pot, water within the pot is brought to boil and boiling water then enters the steamer to wash the rice. When water level falls below the steamer, rice and water will be separated. Heating is then continued, and the steam produced is used to cook the rice through steaming. As part of the sugar content of the rice is washed into the rice soup by the water, the cooked rice will have low GI (Glycemic Index).
Steamers of the prior art present some operational inadequacies. Since water is boiled within the internal pot, if the operational duration of and control over the heating element are not properly managed, it can lead to over-spilling of the water from the internal pot due to vigorous boiling, which in turn presents a safety hazard. At the same time, due to vigorous boiling, the water is unable to come into stable contact with the rice, and this affects absorption of water by the rice, and hence compromises the taste of the cooked rice.
Summary
The object of the present invention is to provide an electric cooker that can overcome the current problems of potential safety hazards and compromise in
taste of cooked rice caused by the vigorous boiling of water in the internal pot.
To achieve the above object, the present invention provides an electric cooker that comprises an internal pot; a steamer housed within the internal pot, and the bottom of the steamer has an open structure that extends towards the bottom wall and/or side wall of the internal pot, the steamer comprises a water permeable area and a bearing cavity positioned above said water permeable area, an open top space formed by said open structure is interconnected with the bearing cavity through the water permeable area, a separating cavity exists between the exterior wall of the steamer and the interior wall of the internal pot, and this separating cavity is interconnected with the bearing cavity through the open top space; a spill detection unit that is used for detecting the water level in the bearing cavity, and which has its detection end connected with the bearing cavity.
Further, the top of the steamer can be connected to the mouth of the internal pot through a sealed connection.
Further, the electric cooker also comprises an external housing which holds the internal pot; a top cover that is positioned on the external housing, and which is connected to the first end of the spill detection unit, and the second end of the spill detection unit extends towards the base of the internal pot. Further, the spill detection unit is at least one probe selected from the group comprising a spill detection probe, temperature probe, water level detector, infrared probe and ultrasound probe.
Further, the spill detection unit comprises: an insulated housing; a first spill detection electrode, which is positioned on the insulated housing; a second spill detection electrode, which is positioned on the insulated housing, and the detection ends of the first and second spill detection electrodes are positioned at different locations along the height of the bearing cavity, such that there is a
difference in height between the two electrodes.
Further, the first end of the insulated housing is connected with the top cover, and the second end of the insulated housing extends towards the bottom wall of the internal pot. The insulated housing has a hollow cavity that extends from the first end to the second end of the insulated housing along its length; the first spill detection electrode takes the shape of a rode and is positioned within said hollow cavity, and the detection end of this first spill detection electrode extends outwards from the second end of the insulated housing; the detection end of the second spill detection electrode is positioned on the side wall of the insulated housing, and the detection ends of the first and second spill detection electrode are positioned at different locations along the height of the bearing cavity, such that there is a height difference of H I between the two electrodes.
Further, this height difference H I is at least 1 millimetre and at most 50 millimetres. Further, H I is at least 3 millimetre and at most 30 millimetres.
Further, the first end of the insulated housing is connected with the top cover, and the second end of the insulated housing extends towards the bottom wall of the internal pot. The insulated housing has a hollow cavity that extends from the first end to the second end of the insulated housing along its length; the first spill detection electrode takes the shape of a rode and is positioned within said hollow cavity, and the detection end of this first spill detection electrode extends outwards from the second end of the insulated housing; the detection end of the second spill detection electrode is positioned on the side wall of the insulated housing, and the detection ends of the first and second spill detection electrode are positioned at different locations along the height of the bearing cavity, such that there is a height difference of H2 between the two electrodes; the spill detection unit further comprises: a third spill detection electrode with
its detection end positioned on the side wall of the insulated housing. The detection end of the second spill detection electrode is positioned in between the detection ends of the first and third spill detection electrodes, and there is a height difference of H3 between the detection ends of the second and third spill detection electrodes along the height of the bearing cavity.
Further, H2 is at least 1 millimetre and at most 30 millimetres, and H3 is at least 1 millimetre and at most 40 millimetres.
Further, H2 is at least 3 millimetres and at most 15 millimetres, and H3 is at least 3 millimetres and at most 25 millimetres. Further, the spill detection unit also comprises a fourth spill detection electrode which is positioned on the side wall of said insulated housing. The detection end of the third spill detection electrode is positioned between the detection ends of the second and fourth spill detection electrodes, and there is a height difference of H4 between the detection ends of the third and fourth spill detection electrodes along the height of the bearing cavity.
Further, H4 is at least 1 millimetre and at most 40 millimetres.
Further, H4 is at least 3 millimetres and at most 25 millimetres.
Further, the fourth spill detection electrode is a plurality of electrodes, and the detection ends of this plurality of fourth spill detection electrodes are placed at intervals away from the first spill detection electrode.
Further, there is a height difference of H5 between two adjacent detection ends of the fourth spill detection electrodes, and H5 is equal to H4.
In the technical solution of the present invention, a steamer is housed within the internal pot, and the bottom of the steamer has an open structure that extends towards the bottom wall and/or side wall of the internal pot. The steamer
comprises a water permeable area and a bearing cavity positioned above said water permeable area. An open top space formed by said open structure is interconnected with the bearing cavity through the water permeable area, and a separating cavity exists between the exterior wall of the steamer and the interior wall of the internal pot. This separating cavity is interconnected with the bearing cavity through the open top space. The detection end of the spill detection unit that is used for detecting the water level in the bearing cavity is connected with the bearing cavity.
In the process of cooking using the electric cooker of the structure described above, when the heating element starts to heat up the internal pot, the water underneath the rice will begin to boil. Steam rapidly fills up the separating cavity, which causes the pressure within the separating cavity to rise. A pressure difference is thereby created between the separating cavity and the bearing cavity.
At this time, water is pushed into the bearing cavity by the pressure and comes into contact with the rice within it, and the rice will be consequently soaked and cooked. As boiling continues, pressure within the separating cavity continues to rise, and this causes more water to be pushed from the internal pot into the bearing cavity. During this time, rice comes into adequate contact with water and absorbs a sufficient amount of water, and hence enters the cooking and washing step.
It should be noted that, as boiling intensifies, there is a risk of water spillage, which poses a potential safety hazard. For more effective cooking of the rice and to prevent spillage, the water level in the bearing cavity can be effectively detected through the spill detection unit. When the water level rises and water comes into contact with the spill detection unit, the operation of the heating element is stopped or its power is reduced, so as to lower the water level and prevent spillage. When the water level falls below the detection range of the
spill detection unit, heating of the heating element is resumed to ensure that the rice in the bearing cavity comes into adequate contact with water and thereby absorb a sufficient amount of water. The rice washing and cooking step is completed in cycles. It is evident that the water level in the bearing cavity can be effectively detected by means of a spill detection unit to prevent water spillage due to excessive boiling and to produce good tasting cooked rice. In this way, the electric cooker can automatically subject the rice to washing and water absorption, as well as complete the cooking of the rice in the bearing cavity through boiling followed by steaming. The cooker is hence able to produce cooked rice with low GI and improved taste and nutritional value, which generates a higher level of satisfaction among the users. Hence, the electric cooker of this new invention has strengths such as providing multiple functions, high level of automation and good usability. Description of the Drawings
The drawings constitute a portion of the Description for further understanding of the present invention. These drawings illustrate the embodiments of the present invention and explain the principle of the present invention together with the Description. They are not intended to limit the scope of the invention. In the drawings:
FIG. 1 is a schematic view of the structure of an electric cooker according to an optional embodiment of the present invention;
FIG. 2 depicts the relative positions of the internal pot, steamer and spill detection unit in FIG. 1 before the rice comes into contact with water; FIG. 3 depicts the relative positions of the internal pot, steamer and spill detection unit in FIG. 1 when water comes into contact with the rice and spill
detection unit;
FIG. 4 is a schematic view of the structure of an electric cooker according to another optional embodiment of the present invention;
FIG. 5 shows a partial enlarged view of area P in FIG. 4. FIG. 6 is a schematic view of the structure of the spill detection unit according to another optional embodiment of the present invention; and
FIG. 7 is a schematic view of the structure of the spill detection unit according to another optional embodiment of the present invention;
With reference to the above FIG., wherein like parts are indicated by like reference numbers:
10. Internal pot; 20. Steamer; 2 1 Open structure; 21 1 . Open top space; 22. Water permeable area; 23. Bearing cavity; 30. Separating cavity; 40. Spill detection unit; 41 . Insulated Housing; 42. First spill detection electrode; 43. Second spill detection electrode; 44. Third spill detection electrode; 45. Fourth spill detection electrode; 50. External housing; 60. Top cover; 70. First sealing ring.
Detailed Description
It should be noted that the particular features of any specific embodiment may be combined in any suitable manner with one or more other specific embodiments. Representative embodiments of the present invention are explained hereinafter with reference to the accompanying drawings.
It is to be understood that the following detailed description are exemplary and explanatory, and are intended to provide further explanation of the invention. Unless otherwise defined, all terms (including technical and scientific terms)
used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
In the present invention, terms indicating orientation or direction, such as "up, down, top or bottom" are not intended to be absolute terms unless the context requires or indicates otherwise. These terms will normally refer to orientations shown in the drawings. Similarly, to facilitate understanding and description, "internal" and "external" refer to a positioning with respect to the boundary of the part itself. The above terms are not intended to restrict the scope of this invention. The present invention provides an electric cooker that can overcome the current problems of potential safety hazards and compromise in taste of cooked rice caused by the vigorous boiling of water in the internal pot.
As shown in FIG. 1 to 7, the electric cooker comprises internal pot 1 0; steamer 20 housed within internal pot 10; spill detection unit 40 for detecting the water level in bearing cavity 23. The bottom of steamer 20 has an open structure 2 1 that extends towards the bottom wall and/or side wall of internal pot 10. Steamer 20 comprises water permeable area 22 and bearing cavity 23, which is positioned above water permeable area 22. The open top space 21 1 formed by open structure 21 is interconnected with bearing cavity 23 through water permeable area 22. A separating cavity 30 exists between the exterior wall of steamer 20 and the interior wall of internal pot 10. Separating cavity 30 is interconnected with bearing cavity 23 through open top space 21 1 . Spill detection unit 40 has its detection end connected with the bearing cavity 23.
In the process of cooking using the electric cooker of the structure described above, when the heating element starts to heat up internal pot 1 0, water underneath the rice will begin to boil. Steam rapidly fills up separating cavity 30, which causes the pressure within separating cavity 30 to rise. A pressure
difference is thereby created between separating cavity 30 and bearing cavity 23. At this time, water is pushed into bearing cavity 23 by the pressure and comes into contact with the rice within it, and this causes the rice to be soaked and cooked. As boiling continues, pressure within separating cavity 30 continues to rise, and this causes more water to be pushed from internal pot 1 0 into bearing cavity 23. During this time, rice comes into adequate contact with water and absorbs a sufficient amount of water, and hence enters the cooking and washing step.
It should be noted that, as boiling intensifies, there is a risk of water spillage, which poses a potential safety hazard. For more effective cooking of the rice and to prevent spillage, water level in bearing cavity 23 is detected using spill detection unit 40. When water level rises and water comes into contact with spill detection unit 40, the operation of the heating element is stopped or the power of the heating element is reduced, and this lowers the water level and prevents spillage. When the water level falls below the detection range of spill detection unit 40, heating of the heating element is started again to ensure that the rice in bearing cavity 23 comes into adequate contact with water and absorbs a sufficient amount of water, and the rice washing and cooking step is completed in cycles. It is evident that the water level in the bearing cavity 23 can be effectively detected by means of a spill detection unit 40 to prevent water spillage due to excessive boiling and to produce good tasting cooked rice. In this way, the electric cooker can automatically subject the rice to washing and water absorption, as well as complete the cooking of the rice in bearing cavity 23 through boiling followed by steaming. The cooker is hence able to produce cooked rice with low GI and improved taste and nutritional value, which generates a higher level of satisfaction among the users. Hence, the electric cooker according to the present invention has strengths such as providing
multiple functions, high level of automation and good usability.
In the specific embodiment shown in FIG. 1 to 7, the electric cooker can be an electric rice cooker, pressure cooker, or general cooker, etc. Of course, the electric cooker according to the present invention can also be a microwave oven, which is equipped with internal pot 10 and steamer 20.
Specifically, the top of steamer 20 is connected to the mouth of internal pot 1 0 in a sealed connection. This effectively ensures that when pressure within separating cavity 30 rises, steam pushes the water smoothly through open structure 21 into bearing cavity 23, and steam is prevented from escaping through the top of steamer 20 and the mouth of internal pot 10.
As shown in FIG. 1 , the top of steamer 20 and the mouth of internal pot 10 are sealed using first sealing ring 70.
As shown in FIG. 1 , the electric cooker further comprises external housing 50 and top cover 60, and internal pot 1 0 is housed within the external housing 50; top cover 60 is positioned on external housing 50, and the first end of spill detection unit 40 is connected with top cover 60, and the second end of spill detection unit 40 extends towards the base of internal pot 10. Optionally, the second end of spill detection unit 40 is the detection end. In this way, when the water level within bearing cavity 23 gradually rises, it will come into contact with the detection end of spill detection unit 40, and a spill-prevention signal will be sent by spill detection unit 40 to stop the heating of the heating element.
Optionally, the heating element is a heating device selected from the group comprising a heating plate, heating tube, IH electromagnetic heating device and heating film. In the specific embodiment shown in FIG. 1 to 3 , spill detection unit 40 is at least one probe selected from the group comprising a spill detection probe,
temperature probe, water level detector, infrared probe and ultrasound probe. This means that in addition to the probes and detectors listed above, any sensor that can detect water level or the rise in water level may also be used as spill detection unit 40. With reference to FIG. 4 to 7 , spill detection unit 40 comprises insulated housing 41 , first spill detection electrode 42 and second spill detection electrode 43. First spill detection electrode 42 is positioned on insulated housing 41 . Second spill detection electrode 43 is also positioned on insulated housing 41 . The detection ends of first spill detection electrode 42 and second spill detection electrode 43 are positioned at different locations along the height of bearing cavity 23 , such that there is a difference in height between the two electrodes. By having two spill detection electrodes, and positioning them such that there is a certain height difference between them, the medium, in the form of rice milk, will power both electrodes up upon contact, and trigger the sending of spill prevention signals to stop the heating of the heating element or to reduce the power with which it is being heated.
In the specific embodiment depicted in FIG. 4 and 5 , the first end of insulated housing 41 is connected with top cover 60, and the second end of insulated housing 41 extends towards the bottom wall of internal pot 10. The insulated housing 41 has a hollow cavity that extends from the first end to the second end of insulated housing 41 along its length. First spill detection electrode 42 takes the shape of a rode and is positioned within said hollow cavity. The detection end of first spill detection electrode 42 extends outwards from the second end of insulated housing 41 . The detection end of second spill detection electrode 43 is positioned on the side wall of insulated housing 41 . The detection ends of the first spill detection electrode 42 and second spill detection electrode 43 are positioned at different locations along the height of bearing cavity 23, such that there is a height difference of H I between the two electrodes.
In this specific embodiment, insulated housing 41 acts as a base for integrating both spill detection electrodes into one unit, and ensures that a height difference of H I exists between the electrodes. When the rice milk comes into contact with the first spill detection electrode 42, which is lower, and then rises gradually and comes into contact with the second spill detection electrode 43. Spill prevention signals are triggered and sent to stop the heating of the heating element or to reduce its power. This gives rise to an effective and yet structurally-simple spill detection unit 40.
Insulated housing 41 provides a certain amount of coverage to first spill prevention electrode 42. This first spill prevention electrode 42 is made of a metallic material and can be in the shape of a ring or other shapes.
The range of the height difference H I was optimized through repeated experiments, based on considerations on the operational efficiency of the electric cooker, its operational safety, taste of the cooked food and other factors.
Optionally, H I is at least 1 millimetre and at most 50 millimetres.
Optionally, H I is at least 3 millimetres and at most 30 millimetres.
In the specific embodiment depicted in FIG. 6 , spill detection unit 40 further comprises a third spill detection electrode 44. The first end of insulated housing 41 is connected with top cover 60, and the second end of insulated housing 41 extends towards the bottom wall of internal pot 10. Insulated housing 41 has a hollow cavity that extends from the first end to the second end of insulated housing 41 along its length. First spill detection electrode 42 takes the shape of a rode and is positioned within said hollow cavity, and the detection end of first spill detection electrode 42 extends outwards from the second end of insulated housing 41 . The detection end of second spill detection electrode 43 is positioned on the side wall of insulated housing 41 , and the detection ends of
the first spill detection electrode 42 and second spill detection electrode 43 are positioned at different locations along the height of bearing cavity 23, such that there is a height difference of H2 between the two electrodes. The detection end of third spill detection electrode 44 is positioned on the side wall of insulated housing 41 . The detection end of second spill detection electrode 43 is positioned in between the detection ends of first spill detection electrode 42 and third spill detection electrode 44, and there is a height difference of H3 between the detection ends of the second spill detection electrode 43 and third spill detection electrode 44 along the height of bearing cavity 23. The working principle is similar to that of the spill detection unit 40 that is equipped with two spill detection electrodes. More control features are available with the use of three spill detection electrodes.
In this specific embodiment, first spill detection electrode 42, second spill detection electrode 43 and third spill detection electrode 44 are all collected on insulated housing 41 . Further, insulated housing 41 provides a certain amount of coverage to first spill detection electrode 42, second spill detection electrode 43 and third spill detection electrode 44, to ensure that the electrodes do not detach easily. At this time, through the use of a combination of three spill detection electrodes, temperature and water level can be monitored so as to control the electric cooker through stopping the heating or reducing the power of the heating element, and other mechanisms. For example, first spill detection electrode 42 can be used to prevent spillage, and second spill detection electrode 43 and third spill detection electrode 44 can be used to detect water level and other information. First spill detection electrode 42 and second spill detection electrode 43 can be used together to monitor if the water level within bearing cavity 23 has risen to a specified height; first spill detection electrode 42 and third spill detection electrode 44 can be used together to prevent spillage.
The ranges of the height differences H2 and H3 were optimized through repeated experiments, based on considerations on the operational efficiency of the electric cooker, its operational safety, taste of cooked food and other factors. Optionally, H2 is at least 1 millimetre and at most 30 millimetres, and H3 is at least 1 millimetre and at most 40 millimetres.
Optionally, H2 is at least 3 millimetres and at most 1 5 millimetres, and H3 is at least 3 millimetres and at most 25 millimetres.
In the specific embodiment shown in FIG. 7, spill detection unit 40 further comprises fourth spill detection electrode 45 , and fourth spill detection electrode 45 is positioned on the side wall of insulated housing 41 . The detection end of third spill detection electrode 44 is positioned between the detection ends of fourth spill detection electrode 45 and second spill detection electrode 43, and there is a height difference of H4 between the detection ends of the third spill detection electrode 44 and fourth spill detection electrode 45 along the height of bearing cavity 23. The difference between this embodiment and that illustrated in FIG. 6 is that there is an additional fourth spill detection electrode 45 in this embodiment. In this way, more control features can be further realized. In this specific embodiment, first spill detection electrode 42, second spill detection electrode 43, third spill detection electrode 44, and fourth spill detection electrode 45 are all collected on insulated housing 41 . Further, insulated housing 41 provides a certain amount of coverage to first spill detection electrode 42, second spill detection electrode 43 , third spill detection electrode 44, and fourth spill detection electrode 45 to ensure that the electrodes do not detach easily. At this time, through the use of a combination of four spill detection electrodes, water level can be monitored so as to control
the electric cooker through stopping the heating or reducing the power of the heating element, and other mechanisms.
The range of the height difference H4 was optimized through repeated experiments, based on considerations on the operational efficiency of the electric cooker, its operational safety, taste of cooked food and other factors.
Optionally, H4 is at least 1 millimetre and at most 40 millimetres.
Optionally, H4 is at least 3 millimetres and at most 25 millimetres.
In the embodiment shown in FIG. 7, fourth spill detection electrode 45 is a plurality of electrodes, and the detection ends of this plurality of fourth spill detection electrodes 45 are placed at intervals away from first spill detection electrode 42. In this way, any two adjacent fourth spill detection electrodes 45 will have consistent gradient changes, which facilitates processing, manufacturing and realization of the control features.
Optionally, the height difference H5 between two adjacent detection ends of the fourth spill detection electrodes 45 is equal to H4. Of course, H5 need not necessarily be equal to H4.
It should be noted that technological terms used herein are merely used to describe a specific embodiment, but not to limit the present invention. In this application, the terms "comprising" and "including" should not be construed to necessarily include all of the elements or steps disclosed herein, and should be construed not to include some of the elements or steps thereof, or should be construed to further include additional elements or steps and/or combinations thereof.
Terms including an ordinal number such as first or second may be used to describe various components, but the terms need not necessarily indicate a
specific sequence or order. It should be understood that the above terms are interchangeable, where appropriate, such that the specific embodiments described herein can be implemented in orders or sequences other than those indicated in the FIG. and descriptions contained herein.