TECHNICAL FIELD

[001] The present subject matter relates in general to heating devices and in particular, to an electromagnetic induction iron.

BACKGROUND

[002] An electromagnetic induction heating device works on the principle of generating heat due to eddy currents that are induced in the heating devices due to electromagnetic field. In such heating devices, a metal plate of the heating device is placed in an electromagnetic field such that eddy currents are induced in the metal plate. The induced eddy currents generate heat in the metal plate. For example, an electromagnetic induction iron is an electrical appliance used for ironing of clothes. The electromagnetic induction iron uses electromagnetic induction for heating of a sole metal plate of the electromagnetic induction iron. The electromagnetic induction iron is then moved over clothes for ironing of the clothes. The electromagnetic induction iron is referred as an induction iron, hereafter, for the sake of convenience in readability.

[003] For heating of the metal plate of the induction heating devices, such as a sole plate of the induction iron, the induction iron is placed over a heating platform which emits rapidly alternating electromagnetic waves. The electromagnetic waves penetrate the sole metal plate which induces eddy currents in the sole metal plate of the induction iron. The induced eddy currents cause the heating of the sole metal plate of the induction iron. When the sole plate is heated to a desired temperature, a user lifts the induction iron from the heating platform and thereafter irons his clothes. It is to be noted that while the user is ironing the clothes, the sole metal plate is not being energized, i.e., it is not being heated (as it is removed from the heating platform which heats up the sole plate). Thus, during ironing of the clothes, the sole metal plate tends to lose heat rapidly. [004] Generally, induction irons do not include any mechanism to compensate for the heat loss, thus, the performance efficiency of such induction iron is low. Consequently, such induction irons consume more electric power. Further, due to low heat retention capacity of the sole metal plate, the user has to frequently put the induction iron on the heating platform which causes further inconvenience to the user.

BRIEF DESCRIPTION OF DRAWINGS

[005] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digits of a reference number identify the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference, like features and components.

[006] Figures la and lb illustrate a heating assembly in accordance with an example of the present subject matter;

[007] Figures 2 illustrates a heating assembly according to another example implementation of the present subject matter.

[008] Figure 3 shows an exploded view of the heating assembly in accordance with an example implementation of the present subject matter;

[009] Figures 4a and 4b show a heating assembly in accordance with another example implementation of the present subject matter; and

[0010] Figures 5a and 5b show an electric iron according to an example implementation of the present subject matter.

DETAIFED DESCRIPTION

[0011] The present subject matter provides a heating assembly which has improved heat retention capability and can be used in an electromagnetic heating device, such as an induction iron. The heating assembly of the present subject matter comprises a first metal plate which is to be coupled to a source of the electromagnetic radiation. Further, the heating assembly comprises a second metal plate positioned in contact with the first metal plate such that a first surface of the second metal plate is in contact with first metal plate. The first metal plate further comprises at least one recess to provide a passage to electromagnetic radiation such that the electromagnetic radiation penetrates to the second plate. Further, a second surface of the second metal plate is covered with a heat insulator plate.

[0012] The electromagnetic radiations induce eddy current in the second metal plate and the second metal plate gets heated. The heat is transferred to the first metal plate from the second metal plate via thermal conduction. Thus, the first metal plate also gets heated and can be used for purposes, such as ironing clothes when the heating assembly is coupled with an induction iron. As the second metal plate is covered with a heat insulator plate on one side and first metal plate on the other side, heat loss from the second metal plate is minimum. The heat is transferred from the second metal plate to the first metal plate through conduction till thermal equilibrium is achieved.

[0013] Thus, the multilayer configuration of the heating assembly of the present subject matter helps in retaining heat for longer period of time. This increases the performance efficiency of the heating assembly and also improves the user’s experience.

[0014] Aspects of the present subject matter related to heating assembly for an electromagnetic induction electric iron will now be described in detail in conjunction with the following figures. It should be noted that the description and figures merely illustrate the principles of the present subject matter along with examples described herein and should not be construed as a limitation to the present subject matter. It is thus understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and specific examples thereof, are intended to encompass equivalents thereof.

[0015] Figure la shows a heating assembly 100. A side view of the heating assembly 100 is shown in figure lb. The heating assembly 100 comprises a first metal plate 102. The heating assembly 100 further comprises a second metal plate 104 positioned in contact with the first metal plate 102. A first surface (not shown here, shown in figure 3) of the second metal plate 104 is in contact the first metal plate 102. The first metal plate 102 may be electromagnetically coupled to a source of electromagnetic radiation. When coupled, the electromagnetic radiations from the source are incident on the first metal plate 102. The first metal plate (which is of non-ferrous nature) 102, comprises at least one recess 106 which allows the electromagnetic radiation to pass through the first metal plate 102 and reach the second metal plate 104, which is ferromagnetic. The second metal plate 104 is heated due to electromagnetic radiation. In an example, only one recess 106 is shown in the figure for simplicity, however, it should be understood that a plurality of recesses may be possible. In an embodiment, the at least one recess 106 may run from end-to-end on the first metal plate 102. In another embodiment, the at least one recess 106 may run across the surface of the first metal plate 102 in regular and irregular shapes.

[0016] When the second metal plate 104 is heated due to electromagnetic induction, the heat is transferred to the first metal plate 102 due to thermal conduction and the first metal plate 102 also gets heated. The heating assembly 100 further comprises a heat insulator plate 108 positioned in contact with a second surface (shown in figure 3) of the second metal plate 104. The heat insulator plate 108 prevents the second metal plate 104 from losing heat into surroundings. The second metal plate 104 lies in between the first metal plate 102 and the heat insulator plate 108. The first metal plate 102 is gradually heated based on the heat dissipation rate of the first metal plate 102 and thus the heat from the second metal plate 104 is transferred to the first metal plate 102 in a uniform manner. Further, the heat insulator plate 108 prevents heat loss from the second metal plate 104 into the environment. Thus, the heat is retained in the second metal plate 104 for significantly long period of time.

[0017] Figure 2 illustrates a heating assembly 200 according to another example implementation of the present subject matter. Figure 2 shows a heating assembly 200, similar to the heating assembly 100, with a first metal plate 202. A recess 204-1 on the first metal plate 202 is shown in the figure 2. In an example and for simplicity of understanding, one recess 204-1 is shown in the first metal plate 202 and it should be understood that a plurality of recesses may be provided in the first metal plate 202. The heating assembly 200 further comprises a second metal plate 206 and a heat insulator plate 208, similar to the second metal plate 104 and heat insulator plate 108 described above.

[0018] The recess 204-1 have a depth 210 equal to a thickness 212 of the first metal plate 202. Thus, the recess 204-1, in one example, may be like a rectangular slit which allows the electromagnetic radiation to pass through it and reach the second metal plate 206. The electromagnetic radiations incident on the metal plate 202 also incident on the recess 204-1 and passes through the recess 104-1 to reach the second metal plate 206. In an example, the first metal plate 202 is non-ferrous, such as aluminum such that no heating effect takes place due to electromagnetic radiation falling on the first metal plate 202. The electromagnetic radiations falling on the recess 204-1 passes through the recess 204-1 to reach the second metal plate 206. Had the recess 204-1 not been there on the first metal plate 202, the electromagnetic radiation would not have been able to penetrate through the thickness 212 of the first metal plate 202 to reach the second metal plate 206.

[0019] In an example, the second metal plate 206 is ferrous in nature such that the eddy currents are induced in the second metal plate 206 due to the electromagnetic radiation. Due to the eddy currents, the second metal plate 206 gets heated. Further, the first metal plate 202 is also heated due to conductive heat transfer from the second metal plate 206.

[0020] The recess 204-1 is shown in a rectangular form, in an example, however, in other examples, other shapes, such as circular, oval, square, triangular, pentagonal, etc., of the recess 204- 1 may be possible. In an embodiment, the recess 204- 1 may have a nearly circular shape. [0021] Further, in an example a width of the recess 204- 1 may be in range of 0.2 -1.0 millimeters (mm). Furthermore, in an example, the thickness of the first metal plate 202 may be in range of 1 -3 mm while the thickness of the second metal plate 206 may be in range of 6-7 mm.

[0022] Figure 3 shows an exploded view of a heating assembly 300. The heating assembly 300 comprises a first metal plate 302 having a recess in form of a slit 304. A second metal plate 306 is positioned above the first metal plate 302. The second metal plate 306 has a first surface 308 (bottom surface of the second metal plate 306) which is in contact with the first metal plate 302. Electromagnetic radiations falling over the first metal plate 302 (on a front surface 310 of the metal plate 302) pass through the slit 304 and reach the second metal plate 306. Due to electromagnetic radiations, eddy currents are induced in the second metal plate 306 and the second metal plate 306 gets heated. Also, due to thermal conduction, the first metal plate 302 also gets heated. Further, a heat insulator plate 312 may be placed over a second surface 314 (top surface) of the second metal plate 306 to prevent the heat loss from the second surface 314 of the second metal plate 306. In an example, the heat insulator plate 312 may be made up of materials, such as Bakelite, glass, ceramic, plastic, fiber etc. In an example, the heating assembly 300 may be coupled with a heating appliance through the heat insulator plate 312. For example, a housing of an induction iron may be coupled to the heating assembly 300 via the heat insulator plate 312.

[0023] Figures 4a and 4b show a heating assembly 400 in accordance with another example of the present subject matter. Figure 4a shows the front view of the heating assembly 400 while figure 4b shows the side view of the heating assembly 400. In an example, the heating assembly 400 may comprise a first metal plate 402, a second metal plate 404, and a heat insulator plate 406. The first metal plate 402 may comprise a plurality of recesses 408 which provide a passage for the electromagnetic radiations to reach the second metal plate 404. The second metal plate 404 may be a ferrous metal plate which gets heated due to electromagnetic radiation while the first metal plate 402 may be non-ferrous metal plate which does not get heated due to electromagnetic radiations. In an example, the electromagnetic radiation reaches the second metal plate 404 via the plurality of recesses 408 and the second metal plate 404 gets heated. The heat developed in the second metal plate 404 is transferred to the first metal plate 402 via thermal conduction and the first metal plate 402 also gets heated. Further, the heat insulator plate 406 prevents any heat loss from the second metal plate 404. Thus, as the second metal plate 404 is covered with the first metal plate 402 on one surface and is covered with the heat insulator plate 406 on the other surface, the heat loss is minimal. Also, the heat is transferred to the first metal plate 402 gradually in accordance with the rate of dissipation of heat from the first metal plate 402 till there is a thermal equilibrium. Thus, the heat is retained in the second metal plate 404 for a longer period of time as compared to the time period for which a metal plate would have retained the heat, without above arrangement.

[0024] Further, in an example, the diameter of the plurality of recesses 408 may be in range of 0.2- 1.0 mm while the thickness of the first metal plate 402 may be in range of 1-3 mm. In an example, a depth of the plurality of recesses 408 is equal to the thickness of the metal plate 402. Thus, the plurality of recesses 408 may be like through holes in the first metal plate 402.

[0025] Figure 5 a shows an induction iron 500 according to an example implementation of the present subject matter. According to the present subject matter, the induction iron 500 of the present subject matter comprises a housing unit 502 to which a heating assembly 504 is coupled. The heating assembly 500 comprises a first metal plate 506, a second metal plate 508, and a heat insulator plate 510. The induction iron 500 may be kept in an electromagnetic field (explained in figure 4b) such that the first metal plate 506 lies under the influence of the electromagnetic field.

[0026] The induction iron 500 further comprises at least one recess 512 on the first metal plate 506. In the figure, the recess 512 is shown in rectangular form, however, it may be understood that the recess 512 may be of any shape, such as rectangular, circular, pentagonal, etc. Further, a plurality of recess may be provided on the first metal plate 506 in an example. The recess 512 allows the electromagnetic radiation to pass through it and reach the second metal plate 508 positioned behind the first metal plate 506. The second metal plate 508 gets heated due to electromagnetic induction and the heat is further transferred to the first metal plate 506, via thermal conduction.

[0027] In an example, the recess 512 may be similar to the recess 204-1, as shown in the figure 2. In other words, the recess 512 may have a depth equal to a thickness of the first metal plate 506. Further, in an example, the recess 512 may be circular recesses as shown in figure 4.

[0028] In an example, the housing unit 502 may be made up of non-conductive material, such as plastic, fiber, fiberglass, rubber etc. Further, in an example, the second metal plate 508 may be made up of ferrous metal, ferrous alloy and the first metal plate 506 may be made up of non-ferrous metal, such as aluminum, brass, copper.

[0029] Figure 5b shows the induction iron 500 in another example of the present subject matter. Figure 5b further shows a device 514 which generates electromagnetic radiation for heating the second metal plate 508 of the induction iron 500. The device 514 may have a platform 516 and an enclosure 518. The induction iron 500 may be kept on the platform 516, such that the first metal plate 506 is in contact with the platform 516. A stopper 520 may stop the induction iron 500 from sliding down the platform 516.

[0030] The enclosure 518 may have an electronic assembly, such as solenoidal coils for generating electromagnetic fields. When a user intends to use the induction iron 500, the user inserts in a plug 520 into a socket and puts the induction iron 500 on the platform 516 such the first metal plate 506 is in contact on the platform 516. As soon as the user inserts the plug 520 into the socket, electric current excites the electric assembly of the device 514 and an electromagnetic field is established around the device 514. As the induction iron 500 lies on the platform 516, the first metal plate 506 of the induction iron also comes into effect of the generated electromagnetic field. The electromagnetic field radiation penetrates the first metal plate 506 via the recesses 512 and reaches the second metal plate 508.

[0031] The electromagnetic field induces eddy currents in the second metal plate 508 which heats up the second metal plate 508. The heat is transferred to the first metal plate 506 from the second metal plate 508 and first metal plate 506 also gets heated. The heat insulator plate 510 prevents the loss of heat from the second metal plate 508 from the other surface of the second metal plate 508 which faces the housing unit 502. The induction iron 500 is kept on the platform 516 till a desired temperature of the first metal plate 506 is achieved. In an example, the induction iron 500 may have a temperature sensor which may measure the temperature of the first metal plate 506 and the same may be indicated to the user. In an example, types of clothes that could be ironed at the corresponding temperature may also be indicated. When the first metal plate 506 of the induction iron 500 is heated to a desired temperature, the user may remove the induction iron 500 from the platform 516 using a handle 526 and may iron the clothes. When the temperature of the metal plate 506 of the induction iron 500 falls below a threshold temperature, the user may again put the induction iron 500 on the platform 516 for metal plate 506 and reheat the same.

[0032] Further, in another example, there may be automatic cut-off system with the device 514 which may prevent the induction iron 500 from heating beyond a desired temperature corresponding to a type of cloth that the user desires to iron. For example, a user may rotate a knob 524 to indicate a type of clothing he desires to iron. A temperature measuring sensor may also be coupled with the platform 516 which may be in contact with the first metal plate 506 when the induction iron 500 is placed on the platform 516. The temperature measuring sensor may measure the temperature of the metal plate 506 and may indicate the same to a user. According to the type of clothes selected by the user, by rotating the knob 524, the device may cut-off the supply when a desired temperature for the selected clothing is achieved, provided that the user has not removed the iron 500 from the platform 516. The device 512 may switch ON the supply when the temperature of the first metal plate 506 falls below a particular threshold temperature. For example, in the figure 5b, the knob is pointed at the‘silk’. Silk should be ironed at 148 °C/300 °F. Thus, when temperature of the first metal plate 506 reaches 148 °C/300 °F, the device 514 may cut-off the supply and when the temperature of the metal plate 506 falls below a threshold temperature, while the induction iron is still on the platform 516, the device 514 may switch ON the power supply. Further, in an example, when the user has kept induction iron 500 on the platform 516 after ironing the clothes, and the device 514 detects that the temperature of the first metal plate 506 is less than the required temperature, the device 514 may switch ON the power supply and may generate electromagnetic field for heating of the first metal plate 506. Further, in an example, the device 514 may cut-off the supply when the iron 500 is not on the platform 516. This helps in saving electric power.

[0033] Although implementations for an electromagnetic induction iron are described, it is to be understood that the present subject matter is not necessarily limited to the specific features of the systems described herein. Rather, the specific features are disclosed as implementations for the electromagnetic induction electric iron.