WO2007100181A1

WO2007100181A1 - Hot floor panel

Info

Publication number: WO2007100181A1
Application number: PCT/KR2006/004903
Authority: WO
Inventors: Ho Young Lee
Original assignee: Ho Young Lee
Priority date: 2006-03-02
Filing date: 2006-11-21
Publication date: 2007-09-07

Abstract

The present invention relates, in general, to hot floor panels to be heated by heating elements and, more particularly, to a hot floor panel, which facilitates installation and maintenance thereof and uses a tile or a slate that radiates far infrared rays using electrically-generated heat. The hot floor panel of the present invention includes a ceramic plate (10), which includes an artificial stone, a tile or a natural stone plate and radiates far infrared rays, a heating element (20), which is placed under the ceramic plate (10) and has a linear or planar shape, and an adiabatic plate (30), which is placed under the heating element (20). The adiabatic plate (30) has a support member (32), which supports the ceramic plate and the heating element, and an adiabatic part (31), which performs heat insulation and absorbs impacts.

Description

HOT FLOOR PANEL

Technical Field

[1] The present invention relates, in general, to hot floor panels to be heated by heating elements and, more particularly, to a hot floor panel, which facilitates installation and maintenance thereof and uses a tile or a slate that radiates far infrared rays using electrically-generated heat. Background Art

[2] Generally, for constructing a system of heating a floor of a room, an oil or gas boiler is provided outside the room and a pipe connected to the boiler is arranged under the floor, or, in the case of use of electricity, the floor is constructed using electric panels.

[3] In the case where the boiler is provided outside the room and the piping work is conducted to construct the floor heating system, there are disadvantages in that construction costs are increased and it is difficult to maintain the system. On the other hand, in the case where the floor heating system is constructed using the electric panels(planar type) or electric heating pipes(linear type), because the system can be constructed without a separate boiler, there is an advantage in that the construction work is simplified. However, in the case of the electric panels, a joint spacing between the electric panels easily widens, and, after one or two years, because the strength of the panels, which are typical made of urethane, are weaken, the panels are easily deformed, thus reducing the lifetime of the panels. Furthermore, there is a disadvantage in that an electric coil embedded in the floor generates a lot of electromagnetic waves, which are harmful to humans.

[4] In an effort to overcome the above problems, planar or linear type heating elements, which reduce the generation of electromagnetic waves and can be easily heated using electricity, have been widely used. In the case of construction of a floor heating system using a planar type heating element, an adiabatic plate is laid on a desired base surface, and the planar type heating element is thereafter layered on the adiabatic plate using a retort pouch film, which is commonly available on the market. Subsequently, finishing work is conducted using a flooring material. However, due to low strength, the planar type heating element may be easily damaged. Furthermore, because the planar type heating element is not resistant to water, there is a danger of a fire resulting from an electric leakage. Furthermore, there is a problem in that, when part of the planar type heating element is damaged, it is difficult to partially repair only the damaged part.

[5] To solve the above problems, a conventional hot floor panel using a planar type heating element is provided with a ceramic plate, which can radiate far infrared rays to promote the health of users. Here, the conventional hot floor panel uses the well known planar type heating element, and a ceramic plate, which is manufactured by mixing at least one of magnetic material, dielectric material and conductive material with inorganic matter including silicic material, by plastic molding. Thus, the planar type heating element evenly heats the ceramic plate, and the heated ceramic plate accumulates and generates heat and simultaneously generates far infrared rays. In detail, as shown in Fig. 1, in a conventional heating panel, a planar type heating element 3 is manufactured by applying conductive paint layers 2 to respective opposite surfaces of a fabric cloth 1, which is weaved using cotton yarns and copper wires and serves as a heat source. The element 3 is interposed between ceramic plates 4 and 4'. However, the conventional heating panel cannot solve the problem of the planar type heating element in that it is not resistant to moisture. Furthermore, the conventional heating panel requires a separate flooring finish. In addition, when the conventional heating panels are constructed to form a floor, in the case where an adiabatic plate, which is made of material such as polystyrene foam having a relatively low stiffness, is attached to the lower surface of the planar type heating element, there is a problem in that the panels may easily vibrate or move. Disclosure of Invention

Technical Problem

[6] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a hot floor panel, which facilitates installation thereof and uses a tile or a slate that radiates far infrared rays using electric heat.

[7] Another object of the present invention is to provide a hot floor panel, which is resistant to moisture and has a structure such that it can be easily repaired and replaced with a new one. Technical Solution

[8] In order to accomplish the above objects, the present invention provides a hot floor panel, including: a ceramic plate including an artificial stone, a tile or a natural stone plate and radiating far infrared rays; a heating element placed under the ceramic plate and having a linear or planar shape; and an adiabatic plate placed under the heating element and having a support member supporting the ceramic plate and the heating element, and an adiabatic part performing heat insulation and absorbing impacts, the support member and the adiabatic part forming a single layer.

[9] The hot floor panel is a single independent panel having the above-mentioned construction and heats the room using heat of the heating element. Furthermore, the hot floor panel may be manufactured into various sizes, and several hot floor panels may be arranged in the same manner as that of typical tiles.

[10] The ceramic plate, which is made of ceramic material, such as artificial stone, a tile, natural stone, etc., that radiates far infrared rays, is disposed at the uppermost layer. If a pattern is formed on the upper surface of the ceramic plate using a printing method, in the same manner as that of the typical tile, it can be used without a separate flooring finish. Furthermore, thanks to characteristics of the ceramic, the ceramic plate can evenly generate and accumulate heat, thus ensuring agreeable heating, in the same manner as that of a hot floor of a Korean traditional in-floor heating system. In addition, the ceramic plate can radiate a large amount of far infrared rays. Moreover, in the case where a plurality of protrusions or acupressure parts is provided on the upper surface of the ceramic plate, an acupressure effect can be exhibited.

[11] In addition, the ceramic plate may have a coupling protrusion and a coupling seat to improve the constructability and the waterproofing ability.

[12] The ceramic plate may include a plate body, and a coupling protrusion and a coupling seat, which are provided on edges of the plate body. The coupling protrusion has a predetermined thickness from the lower surface of the ceramic plate, and has a predetermined length, to which the coupling protrusion protrudes from the plate body outwards. The coupling seat has a predetermined height from the lower surface of the ceramic plate, and has a predetermined depth, to which the coupling seat is recessed from the associated edge of the plate body inwards.

[13] In the ceramic plate, the protruded length of the coupling protrusion may be greater than the recessed depth of the coupling seat. In this case, a gap, which is defined between the ceramic plates and is filled with coupling agent, can be maintained constant. If the protruded length of the coupling protrusion is less than the recessed depth of the coupling seat, the ceramic plates engage with each other without defining therebetween a gap, into which a coupling agent is charged.

[14] Furthermore, the coupling protrusion has a predetermined thickness from the lower surface of the ceramic plate, so that, when the ceramic plates are coupled to each other, the coupling protrusion is inserted into the coupling seat of the adjacent ceramic plate.

[15] Moreover, for achieving attractive finish or comfortable feeling, a soft floor sheet, such as a natural or artificial figured wood sheet or decorative tile(e.g. deco tile of LG Decotile Company), may be attached to the upper surface of the ceramic plate using a bonding agent, such as silicone, epoxy, etc. In addition, a coupling protrusion and a coupling seat may be formed by coupling between the ceramic plate and the soft floor sheet.

[16] The heating element is placed under the ceramic plate. Preferably, various kinds of heating elements, which can convert electric energy into thermal energy, for example, a linear or planar type heating element, or a heating element having a thin layer structure provided with a mesh or a net type heating part, may be used as the heating element. Particularly, because a thin planar, mesh or net type heating element generates few electromagnetic waves unlike a conventional electric heating coil, it has no negative influence on the health of the user's body. Furthermore, the thin planar, mesh or net type heating element facilitates a process of constructing the floor heating system. The heating element of the present invention having the thin layer structure can be easily cut to a size corresponding to the ceramic plate, in the same manner as that of a conventional planar heating element. The ceramic plate and the heating element can be adhered to each other by bonding. Furthermore, the linear, planar, mesh or net type heating element, may be directly printed on the ceramic plate, or the heating part of the heating element may be directly attached to the ceramic plate. Here, because such heating element uses electricity and is thus not resistant to water, when wiring, waterproofness must be ensured.

[17] The adiabatic plate is placed under the heating element. The adiabatic plate can efficiently insulate heat of the heating element such that the floor can be efficiently heated. Furthermore, the adiabatic plate makes it possible for the hot floor panel to sufficiently withstand load applied thereto.

[18] Therefore, the adiabatic plate of the hot floor panel of the present invention includes support members, which are evenly distributed at appropriate positions to withstand and disperse load applied to the hot floor panel, and an adiabatic part, which is coupled to the support members, prevents a heat loss of the heating element, and efficiently absorbs impact and vibration. Here, polystyrene foam such as isopink may be used as the material of the adiabatic part. Of course, it is also preferable that the support members be made of material having adiabatic ability, and adiabatic castable material may be used as a representative example thereof.

[19] When the hot floor panel is constructed on the base surface in the room, the support member directly contact the base surface. Therefore, it is preferable that the support member be planar and have a relatively wide surface area such that it can be reliably fastened to the base surface.

[20] Meanwhile, in the hot floor panel of the present invention, an electric connection device for applying power to the heating element must have superior waterproofing ability, and the usage thereof must be simple to enhance the constructability of the hot floor panel. Typically, because the hot floor panel is constructed on a base surface of a room of a dwelling or office, it is easily exposed to water or moisture. Therefore, it is desirable that the electric connection device used in the hot floor panel of the present invention has superior waterproofing ability, compared to a conventional electric connection device. In other words, a problem of an electric leakage or a short circuit attributable to moisture or water must be reliably prevented.

[21] Preferably, the electric connection device used in the hot floor panel of the present invention includes a plug, having a male terminal, a male terminal covering, which covers the male terminal, and an uneven surface part provided on an end of the male terminal covering; and a socket, having a female terminal corresponding to the male terminal, a female terminal covering, which covers the female terminal, and a protective covering extending a predetermined length from the female terminal covering to cover the male terminal covering, with a compression ring fitted at a predetermined position over a surface of the protective covering.

[22] The hot floor panel of the present invention is embodied by coupling among the ceramic plate, the heating element and the adiabatic plate. Here, the present invention provides various methods of coupling the ceramic plate to the adiabatic plate to make it convenient to construct the hot floor panel and to make it possible to use the constructed hot floor panels for a long period without being deformed or misaligned. As a representative embodiment, coupling protrusions and coupling seats are formed by coupling the ceramic plate to the adiabatic plate such that they are misaligned. Then, the hot floor panels can be conveniently and firmly constructed on the base surface using the coupling protrusions and the coupling seats.

Advantageous Effects

[23] The hot floor panel of the present invention can be easily constructed and provided as a single unit, which has a predetermined size, using a tile or slate having an electric heating function.

[24] Furthermore, in the present invention, because a heating element is directly adhered to the tile or slate, the heating efficiency is increased, and the tile or slate can supplement the weak points in the heating element having relatively low strength.

[25] In addition, in the hot floor panel of the present invention, because the tile (ceramic) or slate has a relatively high far infrared ray radiating efficiency, unlike the typical wood sheet, it is beneficial for the user's health. As well, the hot floor panel may be constructed such that the tile or slate is exposed outside, so that a danger of fire is reduced.

[26] Moreover, when it is desired to repair the heating floor, because only a desired panel can be replaced with a new one, the maintenance and repair are convenient.

[27] In addition, the hot floor panels of the present invention can be easily arranged using the coupling protrusions and the coupling seats, which are formed on the ceramic plates or by coupling between the ceramic plates and the adiabatic plates. Thus, the hot floor panels can be reliably assembled with each other, and a required amount of separate coupling agent is reduced. Furthermore, an electric leakage or short circuit due to permeation of water is prevented by the coupling agent. [28] In the case where the planar heating element made of vinyl is laid on the base surface, there is a danger of an electric leakage attributable to moisture formed under the lower surface thereof. However, in the present invention, because several pieces of panels are laid on the base surface to form ventilation passages, moisture is easily removed through the passages between the panels. Furthermore, reliable waterpr oof ness of the heating element is ensured. Thus, there is no danger of an electric leakage. [29] Moreover, the hot floor panels of the present invention may be provided with a soft floor sheet, thus enhancing the heating efficiency thereof and exhibiting an advantage of comfort feel of the soft floor sheet. [30] In addition, the hot floor panel of the present invention may be provided with acupressure parts, thus exhibiting acupressure effect.

Brief Description of the Drawings [31] Fig. 1 is a perspective view of a conventional heating panel using a planar heating element; [32] Figs. 2a and 2b respectively are a perspective view and a front view of a hot floor panel according to the present invention; [33] Fig. 3 is a perspective view, a plan view and a sectional view showing an embodiment of a ceramic plate of the hot floor panel according to the present invention; [34] Fig. 4 is a perspective view and a plan view showing another embodiment of a ceramic plate of the hot floor panel according to the present invention; [35] Fig. 5 is a perspective view and a plan view showing a further embodiment of a ceramic plate of the hot floor panel according to the present invention;

[36] Fig. 6 and 7a through 7b are perspective views, a sectional view and a plan view illustrating the assembly of the ceramic plates according to the present invention; [37] Fig. 8 is a perspective view and sectional views showing an example of a structure in which a soft floor sheet is attached to a ceramic plate of the hot floor panel according to the present invention; [38] Fig. 9 is a perspective view and sectional views showing another example of a structure in which a soft floor sheet is attached to a ceramic plate of the hot floor panel according to the present invention; [39] Fig. 10 is a perspective view and sectional views showing a further example of a structure in which a soft floor sheet is attached to a ceramic plate of the hot floor panel according to the present invention; [40] Fig. 11 is a perspective view and sectional views showing yet another example of a structure in which a soft floor sheet is attached to a ceramic plate of the hot floor panel according to the present invention; [41] Fig. 12 is a perspective view showing several examples of support members used in the hot floor panel according to the present invention; [42] Fig. 13 illustrates another example of a support member of the hot floor panel according to the present invention, wherein Fig. 13a is a perspective view, and Fig. 13b is a sectional view taken along line A-A of Fig. 13a; [43] Fig. 14 is an exploded perspective view of a planar heating element used as an example of a heating element for the hot floor panel according to the present invention; [44] Fig. 15 shows an embodiment of an adiabatic part of the hot floor panel according to the present invention, wherein Fig. 15a is a front view, and Fig. 15b is a bottom view; [45] Fig. 16 is a sectional view showing a support member inserted into a through hole of the adiabatic part of the hot floor panel according to the present invention; [46] Fig. 17 is a perspective view and a sectional view of a hot floor panel according to another embodiment of the present invention; [47] Fig. 18 is a perspective view, plan views and sectional views showing embodiments of a heating panel of the hot floor panel according to the present invention; [48] Fig. 19 is a perspective view, a plan view and a sectional view showing another embodiment of the heating panel of the hot floor panel according to the present invention; [49] Fig. 20 is a perspective view, a plan view and a sectional view showing a further embodiment of the heating panel of the hot floor panel according to the present invention; [50] Fig. 21 is a perspective view, a plan view and a sectional view showing yet another embodiment of the heating panel of the hot floor panel according to the present invention; [51] Fig. 22 is a plan view and a sectional view illustrating an example of a power connection method in the hot floor panel according to the present invention; [52] Fig. 23 is a schematic front view illustrating construction of the hot floor panels for heating a floor of a room according to the present invention; [53] Fig. 24 illustrates an embodiment of an electric connection device for the hot floor panel according to the present invention; [54] Fig. 25 illustrates another embodiment of an electric connection device for the hot floor panel according to the present invention; [55] Fig. 26 illustrates a further embodiment of an electric connection device for the hot floor panel according to the present invention; [56] Fig. 27 illustrates yet another embodiment of an electric connection device for the hot floor panel according to the present invention;

[57] Fig. 28 is views illustrating an example of a compression ring used in the electric connection device of hot floor panel according to the present invention, showing an enlargement of a portion corresponding to portion A of Fig. 24a;

[58] Fig. 29 is a perspective view and a front sectional view showing a hot floor panel according to another embodiment of the present invention; and

[59] Fig. 30 is a front sectional view of the hot floor panel provided with a ceramic plate having a structure different from that of Fig. 29. Mode for the Invention

[60] Hereinafter, a hot floor panel according to the present invention will be described in detail with reference to the attached drawings.

[61] In the drawings, lengths and thicknesses of elements may be exaggerated to more clearly and conveniently illustrate the present invention. Furthermore, reference should now be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.

[62] Figs. 2a and 2b respectively are a perspective view and a front view of a hot floor panel 100 according to the present invention. The perspective view of Fig. 2a shows the hot floor panel turned upside down.

[63] As shown in Figs. 2a and 2b, a ceramic plate 10, which is disposed at the upper position of the hot floor panel, has a predetermined size and may be made of various materials. As the most typical manner, the ceramic plate is manufactured by molding into a desired size, in a manner similar to that when manufacturing tiles or potteries. Furthermore, the ceramic plate may be made of inorganic matter to have various shapes. In addition, various patterns or figures can be formed on the upper surface of the ceramic plate 10 in the same manner as that of typical tiles or potteries. Thus, there is a characteristic in that an operation of finishing a floor heating system construction can be conducted merely by constructing the hot floor panel of the present invention without using a separate finish. A heating element is placed under the lower surface of the ceramic plate 10. Therefore, the lower surface of the ceramic plate 10 is preferably formed as even as possible.

[64] A thin linear or planar heating element may be used as the heating element 20, which is placed under the lower surface of the ceramic plate 10. Furthermore, various heating elements, having thin layer structures, heating parts of which have mesh or net shapes, may be used. The heating element 20 may be attached to the lower surface of the ceramic plate by various methods using bonding agent, such as epoxy, silicone, etc., or silicone mortar. In particular, in the case where epoxy or silicone is applied to the lower surface of the ceramic plate 10, the lower surface of the ceramic plate can be maintained even, and superior heat transfer efficiency and waterproof effect can be ensured. External power is applied to the heating element 20 through wires 25. In this embodiment, the typical planar heating element, in which carbon plates are connected in parallel to each other between opposite electrodes, is used. In this case, four wires 25 are used. Furthermore, because the heating element 20 is not resistant to moisture, after the wires 25 are coupled to the heating element by soldering or other method, the junctions therebetween are preferably wound using insulating tapes in order to ensure insulation and waterproofness. After the wires have been waterproofed and insulated using the insulating tapes, if a bonding agent such as epoxy is applied to the wiring parts or the entire heating element 20, more reliable waterproofness and insulation are ensured, and it is also beneficial to couple the heating element to an adiabatic plate, which will be explained later herein.

[65] The adiabatic plate 30 is attached to the lower surface of the heating element 20.

The adiabatic plate 30 includes rigid support members 32, which serves as support frames and have a heat insulation function, and an adiabatic part 31, which forms a single layer along with the support members 32 and has stiffness equal to or lower than that of the support members 32. The adiabatic plate is attached to the heating element 20 using bonding agent, epoxy or cement molding agent. In Fig. 2, the support members 32 includes four supports 32a, which are disposed at respective corners of the adiabatic plate, four supports 32b, which are disposed adjacent to respective edges of the adiabatic plate between the four supports 32a disposed at the corners, and a support 32c, which is disposed at the center of the adiabatic plate. Furthermore, sealing parts 33, through which the respective wires 25 extend outside for external wiring, and which hold the respective wires 25 and ensure waterproofness and insulation between the wires 25 and the heating element 20, are integrally formed in the respective supports 32a. The sealing parts 33 may not be formed, but it is preferable that they be used to ensure superior insulation and waterproof ability. Furthermore, preferably, each support member 32 is made of material such as epoxy or cement, which becomes rigid after having hardened and can withstand external load. In addition, material such as plastic having high stiffness may be used as the material of the support member 32. As well, some of the support members or the all support members may be made of synthetic rubber, silicone or urethane to mitigate impact and enhance the vibration- absorbing ability.

[66] The adiabatic part 31 is preferably made of adiabatic material such as polystyrene foam having low stiffness. A typical adiabatic material may be used as the material of the adiabatic part 31, and it is preferable that the adiabatic part 31 be made of material appropriate to absorb vibration or impact while the support members 32 are made of material appropriate to withstand load and impact applied to the hot floor panel, such that the hot floor panel 100 has superior durability after the construction of the hot floor system has been completed. In this embodiment, as a method of forming the support members 32, parts are removed from the adiabatic part 31 to form receiving spaces, in which the support members 32 are formed, and, thereafter, the adiabatic part

31 is attached to the heating element 20, and epoxy, castable material or cement molding agent is charged into the receiving spaces formed in the adiabatic part 31 and is hardened, thus forming the support members 32. Alternatively, the adiabatic part may be attached to the heating element 20, after epoxy, castable material or cement molding agent has been charged into and hardened in the receiving spaces formed in the adiabatic part. Furthermore, the method of directly forming the support members

32 on the heating element 20 can be advantageous to the support member forming and bonding processes. In the case where rigid material such as plastic is used to form the support members, the support members may be previously manufactured through a separate process and fitted into the adiabatic part 31, and, subsequently, the support members, along with the adiabatic part, may be attached to the heating element 20. That is, in the adiabatic plate 30 of the hot floor panel according to the present invention, it is preferable that the material of the support member 32 be harder than the material adiabatic part 31.

[67] In the hot floor panel 100 of Fig. 2, the ceramic plate 10 is larger than the heating element 20. The reason for this is that, although the heating element 20 of the hot floor panel 100 is heated at a temperature of 8O⁰C or less and the heating element 20 is slightly smaller than the ceramic plate 10, thanks to the characteristics of the ceramic plate 10, heat can be evenly transmitted to a degree sufficient to heat the room, and it is preferable that a passage 15 for wiring be formed in the hot floor panel, because the hot floor panel may require separate space for wiring unlike a typical electric panel. Here, in the case of a thin heating element such as the planar heating element, for safety, it is desirable that the heating element is heated at a temperature of 8O⁰C or less. Furthermore, in the case of the method of heating the room by heating the floor of the room, the floor easily absorbs moisture. Thus, it is preferable that the ceramic plate be formed larger than the heating element to form space such that the moisture can be easily removed without affecting the heating element 20.

[68] In addition, the heating element 20 is preferably constructed such that heating parts thereof are disposed inside the supports 31a and 32b. Particularly, in the case of the planar heating element, it is preferable that the carbon plates rather than the electrodes are disposed inside the supports 31a and 32b. Meanwhile, the support members 32 may be formed along with the ceramic plate 10 when it is formed by plastic molding. In particular, the supports disposed adjacent to the edges of the adiabatic plate may be formed along with the ceramic plate 10 using the same ceramic material as that of the ceramic plate 10 through a single process when the ceramic plate 10 is formed by molding. If the heating element 20 is shaped such that it is attached to portions of the adiabatic plate other than the central support 32c, the central support 32c may also be formed along with the ceramic plate 10 by plastic molding. In this case, as necessary, additional wires may be arranged through the adiabatic part. However, it is preferable that the sealing parts 33 be formed through a separate process, and the sealing parts be formed using epoxy, castable or cement molding agent.

[69] Hereinafter, the ceramic plate used in the hot floor panel of the present invention will be explained in detail with reference to the attached drawings. The ceramic plate may be manufactured to have various shapes, but it is preferable that the following ceramic panels be used to enhance the usefulness of the hot floor panel as well as the construe tability and waterproofness thereof.

[70] Figs. 3 through 7 are views illustrating several embodiments of the ceramic plates of the hot floor panel and assembly processes thereof according to the present invention.

[71] Figs. 3a through 3d are a perspective view, a plan view and sectional views of an embodiment of a ceramic plate according to the present invention. Fig. 3d is a plan view of Fig. 3a, and Figs. 3b and 3c respectively are sectional views taken along lines B-B' and C-C' of Fig. 3a.

[72] Referring to Figs. 3a through 3d, the ceramic plate 10 includes a body part 110, coupling protrusions 120, which protrude from edges of the body part 110 to predetermined protruding lengths (Ll), and coupling seats 130, which are recessed inwards from the body part 110 to predetermined recessed depths (L2). Here, the protruding lengths (Ll) of the coupling protrusions 120 may differ from the recessed depths (L2) of the coupling seats 130. Preferably, the protruding lengths (Ll) of the coupling protrusions 120 are greater than the associated recessed depths (L2) of the coupling seats 130.

[73] Thanks to the above-mentioned structure, when the several ceramic plates are assembled with each other to construct the hot floor, gaps between the ceramic plates can be maintained constant, and coupling agent can be prevented from falling down.

[74] Furthermore, widths (Wl and W3) of the coupling protrusions 120 are equal to widths (W2 and W4) of the corresponding coupling seats 130. Here, the position of each coupling protrusion 120 corresponds to the position of the associated coupling seat 130 (that is, in the case where the coupling protrusion 120 is provided on a first edge of the ceramic plate 10, the corresponding coupling seat 130 is formed in a second edge of the ceramic plate 10 which is parallel with the first edge).

[75] In addition, it is preferable that the width (Wl, W3) of each coupling protrusion 120 be less than the length of the edge, on which the coupling protrusion 120 is provided. In the same manner, it is also preferable that the width (W2, W4) of each coupling seat 130 be less than the length of the edge, on which the coupling seat 130 is formed.

[76] As well, although only one coupling protrusion 120 or coupling seat 130 is provided in each edge of the ceramic plate in the drawing, as necessary, two or more coupling protrusions or seats may be provided in each edge of the ceramic plate.

[77] Moreover, in the drawing, although each coupling protrusion 120 has been illustrated as having a trapezoidal shape, which is reduced in width in a direction away from the body part 110, and although each coupling seat 130 has been illustrated as having a trapezoidal shape, which is reduced in width from the edge of the body part 110 to the central portion thereof, the coupling protrusion 120 and the coupling seat 130 may have rectangular parallelepiped shapes. In the case where the coupling protrusion and the coupling seat have trapezoidal shapes as shown in the drawing, there is an advantage in that, when the ceramic plates are coupled to each other, the coupling protrusions 120 can easily engage with the respective coupling seats 130.

[78] Each coupling protrusion 120 has a predetermined thickness (Tl) from the lower s urface of the body part 110, and the coupling seat 130 has a predetermined height (T2) from the lower surface of the body part 110.

[79] Preferably, the thickness (Tl) of the coupling protrusion 120 is equal to the thickness (T2) of the coupling seat 130.

[80] Figs. 4a and 4b respectively are a perspective view and a plan view showing another embodiment of a ceramic plate of the hot floor panel of the present invention.

[81] Referring to Figs. 4a and 4b, unlike the ceramic plate of Fig. 3, in the ceramic plate

10 of this embodiment, coupling protrusions 120 and coupling seats 130 are formed throughout the entire areas of the edges of a body part 110.

[82] In other words, in the ceramic plate 10 of the embodiment of Fig. 3, the body part

110 has portions (the corners of the ceramic plate), on which neither coupling protrusion 120 nor coupling seat 130 is formed. On the other hand, in the ceramic plate 10 of this embodiment, the coupling protrusion 120 or the coupling seat 130 is formed on the entire area of each edge of the body part 110.

[83] Thanks to such structure, when the several hot floor panels including the ceramic plates are assembled with each other to construct the hot floor, gaps between the ceramic plates can be maintained constant, and coupling agent, which fills joint spacing between the plates in the same manner as that of coupling of typical tiles, can be prevented from falling down. That is, in the case of the embodiment of Fig. 3, because neither coupling protrusion nor coupling seat is formed in the corners of the ceramic plate, coupling agent, which is applied to the corners of the ceramic plate, may fall down. However, in this embodiment, this problem is reliably prevented.

[84] Figs. 5a and 5b respectively are a perspective view and a plan view showing another embodiment of a ceramic plate of the hot floor panel of the present invention.

[85] Referring to Figs. 5a and 5b, the ceramic plate 10 of this embodiment includes a body part 110, coupling protrusions, which protrude from edges of the body part 110 to predetermined protruding lengths, and coupling seats, which are recessed inward from the body part 110 to predetermined depths. Unlike the embodiments of Figs. 3 and 4, each coupling protrusion has a first protrusion part 122 and a second protrusion part 124, and each coupling seat has a first seating part 132 and a second seating part 134.

[86] Here, the first protrusion parts 122 and the first seating parts 132 serve to maintain gaps between ceramic plates constant and prevent coupling agent from falling down, in the same manner as in the embodiment of Fig. 4. The second protrusion parts 124 and the second seating parts 134 serve to prevent the ceramic plate from being oriented in an incorrect direction when the ceramic plates are assembled to each other.

[87] The coupling protrusion and seat have various bar shapes such as a triangular bar shape. For example, the coupling protrusion and seat may have the shapes of Figs. 17 and 18.

[88] Figs. 6 and 7a through 7d are perspective views, a sectional view and a plan view illustrating the assembly structures of the ceramic plates of the hot floor panel of the present invention. Fig. 7b is a sectional view taken along line D-D' of Fig. 7a. Fig. 7c is a plan view showing two ceramic plates placed on the line D-D' of Fig. 7a. Fig. 7d is a perspective view illustrating the assembly structure of another type ceramic plate. This embodiment is provided to illustrate the use of a separate coupling agent.

[89] Referring to Fig. 6, the hot floor panels including the ceramic plates 10 of the present invention are constructed on the base surface of the room. This is realized by engaging the ceramic plates 10a, 10b, 10c and 1Od, each of which has coupling protrusions and coupling seats, with each other on the base surface of the room.

[90] Referring to Figs. 7a through 7c, the several ceramic plates 10a, 10b, 10c and 1Od of Fig. 6 are placed such that they are in close contact with each other, and the ceramic plates 10a, 10b, 10c and 1Od are thereafter bonded to each other using coupling agent. In detail, as shown in Fig. 7b, the first and second ceramic plates 10a and 10b are coupled to each other such that a coupling protrusion 120 of the first ceramic plate 10a engages with a coupling seat 130 of the second ceramic plate 10b. The coupling agent 140 is charged into a space defined by a difference between the protruding length of the coupling protrusion 120 and the recessed depth of the coupling seat 130, that is, into a gap (G2), thus bonding the first and second ceramic plates 10a and 10b to each other.

[91] Here, as shown in Fig. 7c, because the coupling protrusion 120a of the first ceramic plate 10a and the coupling seat 130b of the second ceramic plate 10b are formed at positions corresponding to each other and extend the same width, when the coupling protrusion 120a engages with the coupling seat 130b, the first and second ceramic plates 10a and 10b can be placed parallel to each other without being misaligned.

[92] Furthermore, because the protruding length of the coupling protrusion 120a of the first ceramic plate 10a, and the recessed depth of the coupling seat 130b of the second ceramic plate 10b are constant, the gap G2 defined therebetween is also constant. Therefore, the several ceramic plates can be arranged correctly.

[93] Fig. 7d illustrates the ceramic plates 10a, 10b, 10c and 1Od, which are longer and narrower than the ceramic plate of Fig. 7a. In this case, coupling protrusions 120 and coupling seats 130 are formed only on entire longitudinal edges of the ceramic plates without being formed on narrow edges of the opposite ends thereof. Furthermore, the ceramic plates are arranged such that they are staggered with each other. Therefore, even though the coupling protrusions and seats are not formed on the opposite ends of the ceramic plate, the ceramic plates are prevented from moving in transverse directions. In this case, the ceramic plate 10a, which is disposed on the finish end of the floor, is shorter than the other ceramic plates 10b, 10c and 1Od.

[94] As such, in the present invention, the ceramic plate is constructed such that the protruding length of each coupling protrusion and the depth of each coupling seat differ from each other, and the several ceramic plates are coupled to each other such that the coupling protrusions and seats of the adjacent ceramic plates engage with each other. The coupling agent is charged into the gap defined between each coupling protrusion and each coupling seat which engage with each other, thus bonding the adjacent ceramic plates to each other. Therefore, unlike the conventional technique, the coupling agent is saved. In addition, the present invention can solve conventional problems, in that the ceramic plates are not parallel to each other or are twisted relative to each other. Furthermore, in the case where figured wood plates are attached to the ceramic plates, the plates are prevented from being coupled to each other in an incorrect orientation.

[95] In addition, in the case where the hot floor panels using electric heating elements are arranged for the construction of a floor, electric connection devices, which are electrically connected to the heating parts of the heating elements and are placed below the ceramic panels, are prevented from being shorted by water permeated into gaps between the ceramic plates.

[96] Figs. 8 through 11 illustrate several embodiments which are constructed such that a soft floor sheet is attached to the ceramic plate of the hot floor panel of the present invention.

[97] In the present invention, for achieving attractive finish or comfortable feeling, a natural or artificial figured wood sheet or decorative tile may be attached to an upper surface of a ceramic plate using an organic bonding agent, such as epoxy, silicone, vinyl acetate, etc., and, in the case of an artificial wood sheet, it may be attached to the ceramic plate by thermocompression bonding. In this case, compared to the case of the use of only wood panel, the heating efficiency is increased, and there are advantages in that comfort is improved. As representative examples of the soft floor sheet, there are a chemical floor sheet made of PVC or MMA resin, a natural wood sheet, an artificial wood sheet (such as a veneer board), a laminate flooring sheet, a decorative tile, and a reinforced paper board, which is manufactured by compressing several sheets of paper or is made of paper pulp. As such, the material of the soft floor sheet is not limited to special material, as long as it can be formed into a sheet shape and the stiffness thereof is lower than that of the ceramic plate.

[98] Furthermore, the soft floor sheet may be layered on and attached to the ceramic plate such that coupling protrusions and coupling seats illustrated in Figs. 3 and 5 are formed by steps between the soft floor sheet and the ceramic plate.

[99] Figs. 8a through 8c are a perspective view and sectional views showing an example of a structure in which a soft floor sheet is coupled to a ceramic plate of the hot floor panel according to the present invention. Here, Figs. 8b and 8c respectively are sectional views taken along lines B-B' and C-C of Fig. 8a.

[100] Referring to Figs. 8a through 8c, in this embodiment, a soft floor sheet 290 is layered on the ceramic plate 10. A coupling protrusion 150 and a preliminary coupling seat 160 having an "L" shape are formed in the ceramic plate 10. This embodiment is constructed such that the ceramic plates are staggered with each other, in the same manner as that of Fig. 7d, thus a coupling protrusion and a coupling seat are not formed on the opposite ends of the ceramic plate with respect to the longitudinal direction thereof.

[101] In the embodiment of Fig. 8, even if the soft floor sheet 190 has a thickness of approximately 0.5mm, when it is coupled to the ceramic plate, the coupling seat can be appropriately defined. If the thickness of the soft floor sheet is 5mm or more, the heating efficiency is reduced. In this embodiment, a relatively thin soft floor sheet 190 is used. If the soft floor sheet is too thin, the heating efficiency is increased but effects resulting from the characteristics of the soft floor sheet made of material such as wood may be reduced.

[102] When the ceramic plates 10 provided with the soft floor sheets are coupled to each other, the coupling protrusions 150 are inserted into the corresponding coupling seats 160. Here, each ceramic plate may be manufactured such that the size of the coupling protrusion 150 is the same as that of the preliminary coupling seat 160. However, in this embodiment, because the soft floor sheets 190 are brought into contact with each other when the ceramic plates 10 are coupled, the coupling protrusion 150 may be smaller than the preliminary coupling seat 160.

[103] Furthermore, because there is a probability of damage to the ceramic plates 10 attributable to contact therebetween, it is preferable that the contact area therebetween be as small as possible. For this, the ceramic plate may be manufactured such that a lower surface 151 of the coupling protrusion 150 does not contact a bottom 161 of the corresponding coupling seat 160, or, if paint or organic matter is applied to the lower surface 151 of the coupling protrusion 150 or the bottom 161 of the corresponding coupling seat 160, the ceramic plate is prevented from being damaged by contact with the adjacent ceramic plate.

[104] When the hot floor panels 100 are arranged on the base surface, junctions therebetween can be precisely and clearly treated by processing the soft floor sheets made of material such as wood rather than processing the ceramic plates 10 made of hard ceramic that is not easily processed.

[105] These embodiments are provided to illustrate modifications of the hot floor panel

100 such that a ceramic plate, such as a tile, which is a hard floor sheet that is mainly used for heavy walk using shoes, can be used for light walk.

[106] Figs. 9a through 9c show another example of a structure in which a soft floor sheet

190 is layered on a ceramic plate 10, in which Figs. 9b and 9c respectively are sectional views taken along lines B-B' and C-C of Fig. 9a.

[107] Referring to Figs. 9a through 9c, unlike the embodiment of Fig. 8, a coupling protrusion 195 and a preliminary coupling seat 196 are formed in the soft floor sheet 190 such that they are symmetrical with each other. In the case where the thickness of the soft floor sheet 190 is approximately 5mm, although it is difficult to form a coupling seat having a groove shape, the preliminary coupling seat 196 can be easily formed. As such, in the case where the soft floor sheet 190 is relatively thick, this embodiment can be realized.

[108] Figs. 10a through 10c show another example of a structure in which a soft floor sheet 190 is coupled to the ceramic plate 10. Here, Figs. 10b and 10c respectively are sectional views taken along lines B-B' and C-C of Fig. 10a.

[109] Referring to Figs. 10a through 10c, this embodiment has a medium type structure between the embodiments of Figs. 8 and 9. In detail, coupling protrusions 150 and 195 and preliminary coupling seats 160 and 196 are formed on both the soft floor sheet 190 and the ceramic plate 10. This embodiment is preferably used in the case where the thickness of the soft floor sheet 190 is approximately 2.5mm and the overall thickness of the ceramic plate 10 and the soft floor sheet is limited. That is, when it is difficult to completely form the coupling protrusion and seat only using either one of the ceramic plate 10 or the soft floor sheet 190, this embodiment is used.

[110] The embodiments of Figs. 8 through 10 mainly pertain to floor sheets, such as wood floor sheets, which are relatively narrow. However, in the case where the floor sheet has an approximately square shape, it is preferable that coupling protrusions be formed on two edges of the floor sheet and preliminary coupling seats be also formed on the corresponding remaining two edges thereof.

[I l l] Figs. 1 Ia through 1 Ic show another example of a structure in which a soft floor sheet 190 is coupled to the ceramic plate 10. Figs. 1 Ib and 1 Ic respectively are sectional views taken along lines B-B' and C-C of Fig. 11a.

[112] Unlike the above embodiments, in which one coupling protrusion and one coupling seat are formed on each floor sheet so that the floor sheets are constructed such that they are staggered with each other, in the ceramic plate 10 of Fig. 11, two coupling protrusions are formed on respective edges thereof and two preliminary coupling seats are formed on respective edges corresponding to the coupling protrusions, so that the ceramic plates are constructed in the same manner as the construction of typical square tiles, as shown in Fig. 6. In this embodiment, the coupling protrusions 150 and the preliminary coupling seats 160 are illustrated as being formed on the ceramic plate 10.

[113] As shown in the drawing, the two coupling protrusions 150 are formed on the two adjacent edges of the ceramic plate 10, and the two coupling preliminary seats 160, into which coupling protrusions 150 of other ceramic plates are inserted, are formed on the other two edges of the ceramic plate 10. Therefore, when a floor is constructed, the adjacent ceramic plates engage with each other at the four edges thereof, so that the ceramic plates can be reliably coupled to each other.

[114] In Fig. 11, although two pairs of coupling protrusions and preliminary coupling seats have been illustrated as being formed on the ceramic plate 10, as shown in Figs. 9 and 10, the coupling protrusions and the preliminary coupling seats may be formed on the soft floor sheet 190 or on both the ceramic plate 10 and the soft floor sheet 190.

[115] In the above embodiments, it is preferable that the soft floor sheet be layered on the ceramic plate such that the coupling seat can completely receive the corresponding coupling protrusion. In other words, as shown in the drawings, preferably, the soft floor sheet is layered on the ceramic plate such that the coupling seat has a "U" shape. Furthermore, it is preferable that the hot floor panels be constructed on the base such that the soft floor sheets precisely engage together. Thus, preferably, the size of the soft floor sheet is the same as or is greater than that of the ceramic plate.

[116] In addition, in the above embodiments, although each of the coupling protrusions and seats has been illustrated as being formed on the overall length of an edge of the ceramic plate or the soft floor sheet, it may be partially formed on the edge, that is, it may be formed in the same manner as the coupling protrusions and seats of Figs. 3 and 5.

[117] In the hot floor panel of the present invention, the coupling protrusions and seats facilitate the construction of the floor and enhance durability and strength of the floor panels such that the floor is prevented from being deformed or twisted. Furthermore, the coupling protrusions and seats may have various structures, as illustrated below.

[118] In the present invention, the ceramic plate is manufactured by molding using ceramic material, in the same manner as that of a process of manufacturing a typical tile. The process of molding a ceramic material is conducted using a mold under relatively high pressure. Therefore, it is very inconvenient to manufacture a mold for a structure, having a recess formed in the edge thereof like the coupling seat 160 shown in Fig. 8, and to conduct the process of molding the structure. In other words, it is very difficult to manufacture the mold and conduct the molding process, such that, while the ceramic material is vertically compressed at high pressure, the edges thereof are horizontally compressed at the same high pressure. Therefore, it is preferable that the present invention have a structure such that a coupling protrusion and a coupling seat are formed by attaching the soft floor sheet to the ceramic plate.

[119] Furthermore, in the case of a typical wood floor sheet made of material such as natural or artificial wood is used as the floor panel, the floor panel must be relatively thick to form coupling protrusions and seats on edges thereof. In this case, there is a disadvantage in that, because wood has insulating ability so that heat is not easily transferred through the wood floor sheet, the heating efficiency of the floor panel is reduced. To ensure the high heating efficiency of the floor panel, it is preferable that the thickness of the wood floor sheet be not greater than 5mm. However, in consideration of the strength of the coupling protrusion and seat and the structural strength of the floor panel, in the conventional technique, a wood floor sheet having a thickness of 8mm or more is typically used. On the other hand, in the present invention using the ceramic plate provided with a figured wood sheet, because the figured wood sheet can be formed in thickness of 5mm or less, the superior heating efficiency is ensured, the constructability is enhanced, and comfortable feel is ensured.

[120] Figs. 12 and 13 illustrate embodiments of the adiabatic plate of the hot floor panel of the present invention.

[121] Fig. 12 is a perspective view showing other examples of support members 320 used in the adiabatic plate 30 of the hot floor panel 100 according to the present invention. Fig. 12a shows an adiabatic plate having support members 32 similar to that of Fig. 2, having no supports 32b. Fig. 12b shows an adiabatic plate having a circular or elliptical central support 342, unlike the central support 32c of Fig. 2. Fig. 12c shows an adiabatic plate having circular or elliptical supports 352 constituting the support members, unlike the supports 32a, 32b and 32c of Fig. 2. It is preferable that an area of portions of the support members 32 which directly contact the heating parts of the heating element 20 be as small as possible to increase heating efficiency and to prevent the heating element from being damaged. Furthermore, the shapes and arrangement of the support members 32 not limited to special shapes or arrangement, as long as they can evenly disperse and efficiently absorb the load of the hot floor panel 100 of the present invention. Fig. 13a is a perspective view illustrating a hot floor panel 100 that differs from that of Fig. 2, and Fig. 13b is a sectional view taken along line A-A of Fig. 13a. The perspective view of Fig. 13a shows the hot floor panel turned upside down. The embodiment of Fig. 13 uses an adiabatic plate that differs from that of Fig. 2. In detail, unlike the adiabatic plate of Fig. 2, the adiabatic part 331 of the adiabatic plate 330 of the embodiment of Fig. 13 is made of polystyrene foam and has no spaces for rectangular supports 32a and 32b disposed adjacent to the edges of the adiabatic part 31 of Fig. 2. Therefore, the entire size of the adiabatic part 331 may be smaller than the adiabatic part 31 of Fig. 2. Furthermore, the adiabatic plate of Fig. 13 has a space for a central support, in the same manner as that for the central support 32c of Fig. 2. In addition, in this embodiment, a support member 332 is integrally formed into a single body, and is not partially formed into several bodies. In detail, the support member 332 includes an outside support 332a, which is disposed along the outer edge of the adiabatic part 331, a support surface 332b, which forms a lower surface of the adiabatic part 331, and a cross-shaped support 332c, which is disposed at the central portion of the adiabatic part 331. Here, the elements constituting the support member 332 are integrally coupled to each other but are not independent. To form the support member 332, the adiabatic part 331 having a cross-shaped slot at the central portion thereof is attached to a heating element 20 and, thereafter, liquefied adiabatic material such as castable liquefied material is charged into a mold, which is placed such that it surrounds the adiabatic plate. Subsequently, the liquefied adiabatic material is hardened, thus forming the support member. Of course, as well as adiabatic castable, liquefied material such as cement molding agent may be used to form the support member. The support 332a supports a ceramic plate 10 at a position adjacent to the outer edges of the adiabatic part 331 like the support 32a of the prior embodiment, and the central support 332c supports the ceramic plate 10 at the central portion of the adiabatic part 331 like the support 32c of the prior embodiment, thus they generally serve to support the hot floor panel 100. The support surface 332b forms a thin layer under the lower surface of the adiabatic part 331. The entire support surface 332b is directly attached to a base or a base surface, on which the hot floor panel 100 is placed. Therefore, work of attaching the support surface 332b made of castable or cement molding agent to a typical cement base is easier than work using polystyrene foam or other adiabatic part. Furthermore, the attaching force is also superior. As such, it is preferable that the support member 332 be formed using adiabatic castable liquefied material, which is commonly available, to ensure superior adiabatic efficiency. Of course, the shape of the central support 332c may have various shapes, as described in Fig. 12. In the same manner as other embodiments, soft adiabatic material as well as polystyrene foam or isopink may be used to form the adiabatic part 331 of this embodiment. Furthermore, the position of the support 332a corresponds to that of supports 32a and 32b of Fig. 2. That is, in this embodiment, the adiabatic part may have various shapes, compared to the adiabatic plate of Fig. 2.

[123] As well, in the embodiment of Fig. 2, adiabatic castable liquefied material, cement molding agent or epoxy may be further applied to the adiabatic plate 30 to form a coated layer such that the adiabatic plate can be easily attached to the cement base. In this case, thanks to the adiabatic castable liquefied material, the adiabatic efficiency can be further enhanced. The embodiment of Fig. 13 must be regarded as a modification of the other embodiments of the present invention, therefore the corresponding elements of the adiabatic plates of the other embodiments of the present invention may also be modified in the manner similar to the embodiment of Fig. 13, and the remaining elements may be embodied in the same or similar manner.

[124] Fig. 14 is an exploded perspective view of a planar heating element used as an example of a heating element 20 for the hot floor panel 100 according to the present invention. In the planar heating element 20 according to present invention, a PET or a retort pouch film is used as an upper film 21 and a lower film 24, in the same manner as that of typical heating elements, which are manufactured and sold. Furthermore, between the films 21 and 24, carbon plates 22 are connected in parallel with each other between electrodes 23. The carbon plates 22 and the electrodes 23 are printed on the film 21 or 24 and coated with the films 21 and 24 made of PET, thus being waterproofed. Here, for wiring, a wire 23 must be connected to the electrodes 23. Typically, the wire is connected to the electrodes by soldering. In this case, because the soldered portion is poorly resistant to moisture, waterproofing treatment must be conducted. It is preferable that the soldered portion be waterproofed using a waterproofing and insulating tape 29.

[125] In the case where the soldered portion is waterproofed using the insulating tape 29 and is sealed by the sealing part 33, which serves as a support, as shown in Fig. 2, the waterproofing and insulating ability can be further enhanced. As such, because the planar heating element 20 can be reliably waterproofed by waterproofing and insulating the soldered portion, a separate waterproofing process for the heating element is not required.

[126] Although the typical planar heating element has been illustrated as being used as the heating element of the present invention, a linear heating element or various other heating elements, having thin layer structures, heating parts of which have mesh or net shapes, may be used as the heating element of the present invention, if it is protected and waterproofed by films in the same manner as that of the planar heating element. Furthermore, the structure such that the junction between the planar heating element and the wire is waterproofed using the waterproofing and insulating tape 29 may be applied to other heating elements in the same or similar manner.

[127] Meanwhile, in the case where the heating part of the heating element is directly printed or attached to the lower surface of the ceramic plate, the heating part and the electrodes must be insulated and waterproofed. Here, if the entire area of the lower surface of the ceramic plate is coated with epoxy, silicone or a film, the adiabatic plate can be attached to the lower surface of the ceramic plate. Thus, work of waterproofing the heating element and work of attaching the adiabatic plate to the heating element can be conducted through a single process. In addition, in the case where the heating element is directly printed or attached to the lower surface of the ceramic plate, the support members may be formed along with the ceramic plate through a simultaneous plastic molding process. That is, in this case, the heating element is printed or attached to portions of the lower surface of the ceramic plate other than the support members and, thereafter, the printed heating element is waterproofed and insulated using epoxy and the adiabatic plate is simultaneously attached to the heating element.

[128] Fig. 15 illustrates an adiabatic plate of a hot floor panel which has receiving holes for installation of support members and spaces for wiring and installation of a temperature control device. Fig. 15a is a plan view, and Fig. 15b is a bottom view. As shown in Fig. 15, the receiving holes 390 for installation of the support members, which support the hot floor panel, are formed through the adiabatic part 31 at four corners and at the central portion thereof. Furthermore, rectangular through holes 350 for wiring are formed in the adiabatic part 31 at left and right positions, that is, on opposite sides of the central portion of the adiabatic part 31. When viewing the plan view of Fig. 15a, a thin planar electric heating element is attached to the upper surface of the adiabatic part. The wires of the heating element extend to the lower surface of the adiabatic part through the wiring through holes 35. In addition, in the case where a thermo coupler or a bimetal strip is used as a temperature control unit, a temperature control unit seat 370, which has a size and a depth appropriate to receive the temperature control unit, is formed in the adiabatic part. The temperature control unit serves to detect the temperature of the heating element and prevent the heating element from being overheated. It is preferable that the temperature control unit be attached to the upper surface of the adiabatic part to which the heating element is attached, because it is efficient for the temperature control unit to directly contact the heating element. As shown in the bottom view of Fig. 5b, wiring grooves 380 are formed in the lower surface of the adiabatic part to depths ranging from 3mm to 5mm, such that the wires of the heating element, which extend to the lower surface of the adiabatic part through the through holes 350, can extend outside the adiabatic part. Of course, the depth of each wiring groove may be changed depending on the thickness of the wire of the heating element. For example, if a relatively thin wire is used, the depth of the wiring groove is reduced, and, if a relatively thick wire is used, the depth of the wiring groove is increased. The wires of the heating element, which extend to the lower surface of the adiabatic part 31 through the through holes, are arranged along the respective wiring grooves 380 and extend outside through respective support member receiving holes 390a, which are formed adjacent to ends of the wiring grooves. As described above, because the wires pass through the associated support member receiving holes 390a, when support members are formed in the support member receiving holes 390a, the wires are reliably fixed to the adiabatic part.

[129] Furthermore, coating holes 360 are formed at positions adjacent to the four respective corners of the lower surface of the adiabatic part 31. When a planar heating element is used, the coating holes 360 are used as spaces for waterproofing and insulating parts of electrodes of the heating element that remain after some of the electrodes are removed.

[130] The sizes or shapes of the support member receiving holes 390, the wiring grooves

380, the temperature control unit seat 370, the coating holes 360 and the wiring through holes 350 may be changed depending on the kind of heating element. For example, Fig. 2 illustrates the case in which a typical planar heating element, having a structure such that the wires extend from the electrodes formed at the medial portions of the element, is used so that the rectangular through holes 350 are formed at left and right positions, that is, on opposite sides of the central portion of the adiabatic part. However, in the case of a linear heating element, the through holes 350 may be formed at positions adjacent to the edges of the adiabatic part. As such, in response to the characteristics of the heating element, the through holes 350 may be formed at any posit ions appropriate for wiring of the heating element. Furthermore, the other holes or grooves may be modified as necessary. For example, the wiring grooves may also be curved and formed adjacent to the edges of the adiabatic part. In addition, preferably, the support member receiving holes 390 are formed at positions so as not to directly contact the heating element, in order to increase the utilization area of the adiabatic part.

[131] Meanwhile, preferably, the adiabatic plate has a thickness of approximately 10mm, in consideration of the adiabatic efficiency thereof and the overall thickness of the hot floor panel.

[132] Furthermore, although the adiabatic plate of the present invention is illustrated as being manufactured using polystyrene foam for ease of formation of the receiving holes and grooves and the through holes, it is preferable that the adiabatic plate be manufactured using foamed adiabatic material. As well as the foamed adiabatic material, the adiabatic plate may be manufactured using adiabatic castable or cement molding agent such that the receiving holes and grooves and the through holes are formed in the adiabatic plate.

[133] In addition, the support members may be formed by hardening adiabatic castable or cement molding agent. Fig. 16 is a sectional view showing a support body inserted into the receiving hole. As shown in Fig. 16, the support body 530 includes an upper elastic part 531, a support part 532 and a lower elastic part 533. The upper elastic part 531 is made of elastic material such as silicone rubber appropriate to absorb an impact and serves to first absorb load or impact applied to the ceramic plate 10 placed on the adiabatic plate. The support part 532 is made of hardening material, such as epoxy or cement, and serves to withstand a relatively large load or impact applied to the adiabatic plate and the entire hot floor panel. The lower elastic part 533 serves to finally absorb the load or impact to be transmitted from the support part 532 to a base surface (not shown), on which the adiabatic plate is placed. Here, if the elastic parts 531 and 533 are too thick, deformation of the adiabatic plate or the hot floor panel may be induced. If they are too thin, the efficiency of absorbing impact is reduced. Hence, the elastic parts 531 and 533 must be set to appropriate thicknesses. The support body 530 may be manufactured through a separate process and be inserted into the receiving hole 390. Furthermore, a spring having respectively strong elasticity or a spring provided with a stop rod, which limits a change in length of the spring, (for example, a rod that limits the length to which the spring is maximally compressed) may be used as the support part 532. As such, the support body 530 serves to absorb load or vibration applied to the hot floor panel and help to reduce noise transmitted between the floors in structures, such as apartment buildings. In the case where the support body of the present invention is used, preferably, the thickness of the adiabatic plate can be increased to solve problems pertaining to heating efficiency, vibration, load and noise. The support body 530 may be inserted into the adiabatic plate when the pipe arrangement process is conducted, but it is more efficient to conduct the pipe arrangement process after the support body 530 has been previously inserted into the adiabatic plate. As such, the support body 530 may have a structure such that it comprises the elastic part having superior elasticity and the support part having stiffness higher than the elastic body or, alternatively, to have other various structures.

[134] Embodiments of Figs. 17 through 23 are provided to prevent coupling agents from falling down between ceramic plates and to prevent the coupling agents from affecting electric wires, in the same manner as that of the embodiments of Figs. 3 through 5. However, unlike the embodiments of Figs. 3 through 5 to achieve the above-mentioned purposes using the shapes of the ceramic plates, in these embodiments, the purposes are achieved using the coupling relationship between ceramic plates and heating panels. That is, the purposes can be achieved by coupling the ceramic plate to the heating panel such that they are misaligned with each other or by appropriately shaping the heating panel.

[135] Figs. 17a through 17c are perspective views illustrating an embodiment of a hot floor panel according to the present invention.

[136] Referring to Figs. 17a through 17c, the hot floor panel of this embodiment includes a heating panel 200, and a ceramic plate 210, which is placed on the heating panel 200.

[137] The heating panel 200 includes a heating part 220, which supplies heat to the ceramic plate 210, and an adiabatic part 230, which prevents heat generated in the heating part 220 from being transferred to an area, other than the heating part 220 (particularly, to a base surface under the heating panel 200). The heating part 220 corresponds to the heating element 20 of Fig. 2, and the adiabatic part 230 corresponds to the adiabatic part 31 of Fig. 2.

[138] The hot floor panel has protrusion parts and receiving parts on edges thereof. In this embodiment, coupling protrusions 240 and coupling seats 250, which are provided on edges of the heating panel 200, in detail, on edges of the adiabatic part 230, respectively serve as the protrusion parts and the receiving parts.

[139] Here, the coupling protrusions 240 and the coupling seats 250 of the heating panel respectively have shapes opposite the coupling seats and the coupling protrusions of the adjacent heating panels, that is, have symmetrical shapes based on the edges of the adiabatic part 230 thereof.

[140] In other words, the shape of each coupling protrusion 240 of the heating panel 200 is symmetrical to that of the corresponding coupling seat 250 of the adjacent heating panel 200. Thus, when two hot floor panels are coupled to each other, the coupling protrusion 240 of the one hot floor panel engages to the corresponding coupling seat 250 of the other hot floor panel, so that the associated edges of the adiabatic parts 230 of the heating panels 200 are brought into close contact with each other to remove a gap therebetween.

[141] Furthermore, the ceramic plate 210, which is placed on the heating panel 200, may have a first size such that the ceramic plate 210 has the same surface area as that of the heating part 220 of the heating panel 200. In this case, the ceramic plate 210 is placed on the heating panel 200 such that the ceramic plate 210 completely overlaps the heating part 220. Alternatively, the ceramic plate 210 may have a second size such that the surface area of the ceramic plate 210 is larger than that of the heating part 220 of the heating panel 200. In this case, the ceramic plate 210 is placed on the heating panel 200 such that the heating part 220 is inside the ceramic plate 210. As a further al- ternative, the ceramic plate 210, which is placed on the heating panel 200, may have a third size such that the surface area of the ceramic plate 210 is equal to or larger than that of both the heating part 220 and the adiabatic part 230.

[142] An assembly state of each of the heating panels 200 provided with the ceramic plates 210 having three kinds of sizes will be explained. In the case of an assembly of the hot floor panels provided with the ceramic plates 210, each having the first or second size, as shown in Fig. 17c, a gap G (that is, a joint spacing) is defined between the ceramic plates 210. When the hot floor panels are assembled with each other to construct a hot floor, a coupling agent 260 is charged into the gap (G). In the case of the hot floor panels provided with the ceramic plates 210 having the third size, no gap is defined, so that the coupling agent 260 is required, thus simplifying the construction of the hot floor.

[143] Here, cement may be used as the coupling agent 260, which couples the adjacent ceramic plates 210 to each other.

[144] In the hot floor panel of the present invention, because the coupling protrusion and the coupling seat, which respectively serve as the protruding part and the receiving part, are provided in the heating panel, gaps (joint spacing) between the ceramic plates can be maintained constant, and the ceramic plates can be level with each other and be prevented from being oriented in incorrect directions.

[145] The structure and shape of the hot floor panel having the ceramic plate 210 will be explained in detail with reference Figs. 18a through 18f, 19a through 19c, 20a through 20c and 21a through 21c. Here, in Figs. 18a through 18c, only the heating panel 200 is illustrated without the ceramic plate 210 (in particular, the ceramic plate 210 having the first or second size), which is placed on the heating panel 200.

[146] Figs. 18a through 18f are a perspective view, plan views and sectional views showing embodiments of the heating panel of the hot floor panel according to the present invention. Here, Figs. 18c and 18d are sectional views taken along line B-B' of Fig. 18b. Fig. 18f is a sectional view taken along line C-C of Fig. 18e.

[147] Referring to Figs. 18a through 18f, the heating panel 200 of this embodiment of the present invention may have a rectangular shape. The heating panel 200 includes an adiabatic part 230, which prevents heat generated in a heating part 220 from being transferred to an area, other than a ceramic plate, which is placed on the heating panel 200, particularly, to a base surface (not shown) under the heating panel 200. The heating panel 200 further includes support members and coupling protrusions 240 and coupling seats 250, which are provided on edges of the adiabatic part 230 and respectively are protruding parts and receiving parts.

[148] Here, each coupling protrusion 240 is reduced in thickness in a direction away from the associated edge of the adiabatic part 230 to have a shape such that the lower surface thereof is inclined towards to the upper surface thereof to form an inclined surface (see, Figs. 18b through 18d). On the other hand, the part, which defines each coupling seat 250, is increased in thickness from the associated edge of the adiabatic part 230 to the center of the heating panel, so that the upper surface thereof forms an inclined surface.

[149] As such, each coupling protrusion 240 has a shape, in which it protrudes outwards from the associated edge of the adiabatic part 230, and each coupling seat 250 has a shape, in which it is recessed inwards from the associated edge of the adiabatic part 230. In detail, in this embodiment, each coupling protrusion 240 protrudes from the edge of the associated adiabatic part 230 to have a right triangular shape, and each coupling seat 250 is recessed inwards from the associated edge of the adiabatic part 230 to have a right triangular shape.

[150] Here, the adiabatic part 230 may be formed into a shape (see, Fig. 18c), surrounding the edges and the lower surface of the heating part 220, such that the heating part 220 is exposed outside through the upper surface of the adiabatic part 230. Alternatively, the adiabatic part 230 may be formed into a shape such that it covers the entire heating part 220. In the case where the adiabatic part 230 has the shape such that it covers the entire heating part 220, it is preferable that the upper surface of the adiabatic part 230 be thin such that heat generated in the heating part 220 is easily transferred upwards through the upper surface of the adiabatic part 230, or the upper surface of the adiabatic part 230 have a relatively high heat conductivity. In the case where the heating part 220 is exposed outside, it may be directly attached to the lower surface of the ceramic plate 210 by printing or other attaching methods.

[151] To couple the hot floor panels having the heating panels 200a and 200b to each other, one coupling seat 250a of one heating panel 200a engages with the corresponding coupling protrusion 240b of the other heating panel 200b (see, Figs. 18e and 18f). At this time, because the coupling seat 250a and the coupling protrusion 240b of the heating panels 200a and 200b are symmetrical with each other, the coupling protrusion 240b is completely inserted into the coupling seat 250a, so that the facing edges of the heating panels 200a and 200b are brought into close contact with each other without any gap.

[152] Ceramic plates are placed on the respective heating panels 200a and 200b.

[153] Furthermore, the heating panels 200a and 200b respectively includes heating parts

220a and 220b. Each heating part 220a, 220b has therein a heating element, such as a linear type, a planar type, a mesh type or a net type heating element, which can generate heat using electric resistance. To supply electricity to the heating element, the heating parts 220a and 220b are connected to an external power supply.

[154] Figs. 19a through 19c are a perspective view, a plan view and a sectional view showing another embodiment of a heating panel of the hot floor panel according to the present invention. Fig. 19c is a sectional view taken along line D-D' of Fig. 19b.

[155] This embodiment will be explained with reference to Figs. 19a through 19c, focusing on the differences between it and the embodiment of Fig. 18.

[156] In this embodiment, each coupling protrusion 240 has a constant thickness and is reduced in width in a direction away from the corresponding edge of the adiabatic part 230, thus having a trapezoidal shape (see, Fig. 19b). In the same manner, each coupling seat 250 has a constant thickness and is reduced in width from the corresponding edge of the adiabatic part 230 to the center of the heating panel, thus having a trapezoidal shape (see, Fig. 19b). As such, in this embodiment, the coupling protrusion 240 protrudes from the corresponding edge of the adiabatic part 240 into a trapezoidal shape such that the thickness thereof is constant and the width thereof is reduced. The coupling seat 250 is recessed inwards from the edge of the adiabatic part 230 into a trapezoidal shape.

[157] Figs. 20a through 20c is a perspective view, a plan view and a sectional view showing a further embodiment of a heating panel of the hot floor panel according to the present invention. Here, Fig. 20c is a sectional view taken along line E-E' of Fig. 20b.

[158] This embodiment will be explained with reference to Figs. 20a through 20c, focusing on the differences between it and the embodiments of Figs. 18 and 19. Each coupling protrusion 240 is reduced in thickness in a direction away from the corresponding edge of the adiabatic part to have a shape such that both the upper surface and the lower surface of the coupling protrusion 240 are inclined, thus having an isosceles triangular shape (see, Fig. 20a). In addition, each coupling seat 250 is reduced in thickness from the corresponding edge of the adiabatic part to the center of the heating panel to have a shape such that both the upper surface and the lower surface of the coupling seat are inclined, thus having an isosceles triangular shape (see, Fig. 20a).

[159] As such, each coupling protrusion 240 protrudes from the corresponding edge of the associated adiabatic part 230, and each coupling seat 250 is recessed inwards from the corresponding edge of the adiabatic part 230. In other words, the coupling protrusion 240 protrudes from the edge of the associated adiabatic part 230 while maintaining the thickness constant, thus having an isosceles triangular shape having a pointed edge. The coupling seat 250 is recessed inwards from the corresponding edge of the adiabatic part 230 into an isosceles triangular shape.

[160] Figs. 21a through 21c are a perspective view, a plan view and a sectional view showing yet another embodiment of a heating panel of the hot floor panel according to the present invention. Here, Fig. 21c is a sectional view taken along line F-F' of Fig. 21b.

[161] Referring to Figs. 21a through 21c, coupling protrusions 240 and coupling seats 250 are determined by relative positions between the heating panel 200 and the ceramic plate 210, unlike the embodiments of Figs. 17 through 20, in which the coupling protrusions 240 and the coupling seats 250 are provided on the edges of the adiabatic part 230 to have predetermined shapes.

[162] In detail, in this embodiment, the coupling protrusions 240 and the coupling seats

250 are formed by overlapping the heating panel 200 and the ceramic plate 210 such that they are misaligned. Of portions other than the overlapped portions, portions of the heating panel 200 which protrude from the ceramic plate serve as the protruding parts, that is, the coupling protrusions 240, and spaces, defined by the heating panel 200 and portions of the ceramic plate 210 which protrudes from the heating panel 200, serve as the receiving parts, that is, the coupling seats 250 (see, Figs. 21a and 21c).

[163] Here, a heating part 220 may be provided such that it exists within a portion of the heating panel 200 that corresponds to the overlapped portion between the heating panel 200 and the ceramic plate 210, but, as necessary, the heating part 220 may be provided, regardless of the area of the overlapped portion.

[164] As shown in Fig. 21c, when the hot floor panels, each of which has the ceramic plate 210a, 210b, are coupled to each other, it is preferable that the heating panels 200a and 200b are slightly larger than the ceramic plates 210a and 210b to engage the heating panels 200a and 200b with each other such that the ceramic plates 210a and 210b do not contact each other. That is, depending on a difference in sizes between the heating panels 200a and 200b and the ceramic plates 210a and 210b, the size of a gap (in other words, a joint spacing) between the ceramic plates 210a and 210b is determined.

[165] Here, the heating panels 200a and 200b respectively includes heating parts 220a and

220b. Each heating part 220a, 220b has therein a heating element, such as a linear type, a planar type, a mesh type or a net type heating element, which can generate heat using electric resistance. To supply electricity to the heating element, the heating parts 220a and 220b must be connected to an external power supply.

[166] Here, in the case of each of the hot floor panels of the embodiments of Figs. 17 through 20, when several hot floor panels are coupled to each other to construct a floor, junction surfaces between the heating panels are disposed below gaps between the ceramic plates. On the other hand, in the embodiment of Fig. 21, junction surfaces (P) are disposed below the ceramic plates rather than the gaps between the ceramic plates. Therefore, even if the gap is not reliably filled with a coupling agent 260 and outside water thus permeates into the gap, the water is prevented from permeating under the heating panels 200 through the junction surfaces (P). Of course, in the embodiment of Fig. 21, each heating panel may have the same structure as that of one of the embodiments of Figs. 17 through 20.

[167] Figs. 22a through 22c are a plan view and sectional views illustrating examples of a method of connecting an external power supply to the heating parts of the heating panels of the hot floor panels of the present invention. Here, Fig. 22b is an enlarged sectional view showing the portion A taken along line G-G' of Fig. 22a. Fig. 22c is an enlarged sectional view of the portion B, illustrating a connection method different from that of Fig. 22b.

[168] Referring to Figs. 22a through 22c, the heating part 220a, 220b of each heating panel 200a, 200b includes a wire, having a male connector 310a, 310b, and a wire, having a female connector 320a, 320b. On the assumption that one female connector 320b of the female connectors 320a and 320b is connected to an external power supply 330, the male connector 310b is connected to the female connector 320a. Thereby, power of the external power supply 330 can be applied to the heating panels 200a and 200b. Furthermore, as shown in Fig. 22a, a space 290 is defined in the heating panel.

[169] In addition, as shown in Figs. 22b and 22c, electric wiring spaces are defined by removing parts of an insulation part 230a, 230b of each heating panel 200a, 200b (in Fig. 22b, by removing parts of the edges of the heating panel 200a, 200b, and, in Fig. 22c, by removing parts of the lower surface of the heating panel), such that the male connector 310a, 310b and the female connector 320a, 320b are exposed outside. These spaces facilitate connection between the male connector and the female connector when the heating panels 200a and 200b are assembled with each other.

[170] Meanwhile, a coupling agent 260 may be charged into a gap between the ceramic plates, which are placed on the heating panels 200a and 200b.

[171] The heating panels 200a and 200b are placed on a bottom 270 in a room. The bottom 270 comprises a sand layer and a base surface.

[172] Here, if water permeates a junction between the female connector and the male connector, there is a likelihood of a malfunction of the heating parts of the heating panels due to a short circuit. However, in the present invention, because the hot floor panels have the coupling protrusions and the coupling seats, the heating panels are brought into close contact with each other, and the coupling agent is charged into the constant gap between the ceramic plates placed on the heating panels. Therefore, the present invention can reliably prevent permeation of water.

[173] As such, because the coupling structure between the coupling protrusion 240 and the coupling seat 250 can prevent water from permeating the heating panels from the upper surfaces of the ceramic plates, problems, such as a short circuit between the male and female connectors, attributable to water can be prevented.

[174] As described above, in the hot floor panel of the present invention, the coupling protrusion and the coupling seat, which respectively are the protruding part and the receiving part, are provided on the edges of the hot floor panel, in detail, on the edges of the adiabatic part of the heating panel. The several hot floor panels can be assembled together using the coupling between the coupling protrusions and the coupling seats. Furthermore, the coupling agent is charged into gaps defined between the floor sheets placed on the heating panels. In addition, the present invention facilitates the construction of the floor and can prevent the hot floor panels from being twisted in a vertical or horizontal direction. As well, because the heating panels may be brought into close contact with each other, water is prevented from permeating the heating panels from the upper surface of the ceramic plates, so that a short circuit can be prevented from occurring in the electric devices, such as the external power supply and the electric connection devices of the heating parts of the heating panels.

[175] Moreover, because gaps between the ceramic plates can be maintained constant, there are advantages in that the coupling agent is saved, and the superior appearance of the floor is ensured.

[176] Although the coupling protrusions or the coupling seats have been illustrated as being formed on the adjacent edges of the panel in the above-mentioned embodiments, they may be formed on the opposite edges of the panel. In this case, the construction of the floor can be easily conducted merely by orienting the panels such that the coupling protrusions engage with the coupling seats. This case is suitable for a square panel. Therefore, in the case of the hot floor panel having a rectangular shape or other shapes, it is preferable that the coupling protrusions or the coupling seats are formed on the adjacent edges of the panel, as illustrated in the drawings.

[177] Furthermore, in the present invention, after the hot floor panels have been constructed to form a floor, water is reliably prevented from entering through a gap between the adjacent ceramic plates, such that a short circuit attributable to water does not occur in the electric connection devices, which electrically connect the heating parts of the heating panels to each other.

[178] Fig. 23 is a front view illustrating construction of the hot floor panels 100 for heating a floor of a room according to the present invention. To use the hot floor panels 100, the bottom of the room is leveled using cement to form a base (not shown) and, thereafter, wires 25 are arranged using passages 15. Subsequently, the lower surfaces of the adiabatic plates 30 are adhered to the base by bonding or cement- molding. The wires 25 may be connected to each other using separate connectors or using insulating tapes such that they are insulated and waterproofed. The hot floor panels, which are placed parallel with each other, are connected to each other using the wires 25. Furthermore, a temperature sensor, which is not shown in the drawings, may be provided in one hot floor panel to control the supply of electricity, thus controlling the heating temperature. In addition, a temperature control device, such as a bimetal strip, may be provided to prevent the hot floor panels from overheating. Here, it is unnecessary to install such devices in every panel. Although such devices are installed in only one panel, the entire panels can be controlled.

[179] Meanwhile, when the hot floor panels of the present invention are constructed, it is preferable that the electric connection devices be used for electric connection between adjacent hot floor panels. However, the electric connection devices for enabling electric connection between the hot floor panels are located in places which are easily exposed to moisture or a high-humidity environment. Furthermore, in the case where many hot floor panels are used, a possibility of danger induced by an electric leakage or a short circuit is increased. Therefore, it is very important to isolate the electric connection device from water. Thus, it is preferable that the hot floor panel of the present invention use the following electric connection device, which can be reliably isolated from water.

[180] Figs. 24 through 28 illustrate an electric connection device used in the hot floor panel according to the present invention.

[181] Figs. 24a and 24b are views showing an embodiment of an electric connection device for the hot floor panel of the present invention.

[182] Referring to Figs. 24a and 24b, the electric connection device 900 of the present invention includes a plug P and a socket S. Each of the plug P and the socket S is electrically connected to a wire or cable C.

[183] Here, the plug P includes a male terminal 910, which is electrically connected to the wire or cable C, and a male terminal covering 920, which covers portion of the male terminal 910 for protecting and insulating it.

[184] An uneven surface part T, which includes prominences (fi) and depressions ([H]), is provided on an end of the male terminal covering 920 from which the male terminal 910 protrudes outwards.

[185] Furthermore, a waterproof lubricant G is charged into the depressions ([H]). Each prominence (fi) may have a height such that it is level with the surface of the male terminal covering 920, or, alternatively, such that the prominence (fi) protrudes from the surface of the male terminal covering 920.

[186] In addition, the plug P further includes an assistant protrusion E, which is provided on the male terminal covering 920 at a predetermined position, in detail, at a position adjacent to the wire or cable C.

[187] The assistant protrusion E serves to make it convenient for a user to couple the plug

P to the socket S using his/her hand or a coupling tool.

[188] The male terminal 910 is made of a metal substance, which is a conductor. The male terminal covering 920 is made of insulating material such as rubber. [189] Meanwhile, the socket S includes a male terminal 930, which is electrically co nnected to the wire or cable C, and a female terminal covering 940, which covers portion of the female terminal 940 for protecting and insulating it.

[190] The socket S further includes a protective covering 950, which extends a predetermined length from the female terminal covering 940.

[191] Preferably, the protective covering 950 has a length appropriate to cover the male terminal covering 920 of the plug P.

[192] The female terminal covering 940 and the protective covering 950 may be integrally formed using the same material through a single process or may be independently formed using different materials through individual processes.

[193] Preferably, the protective covering 950 is made of elastic material such as rubber having appropriate restoring force such that, even though the inner or outer diameter thereof is changed by external force, it can be returned to the original state using the restoring force.

[194] In addition, the protective covering 950 has an inner diameter equal to or less than the outer diameter of the male terminal covering 920 of the plug P, so that, when the plug P is inserted into the socket S (see, Fig. 24b), the protective covering 950 covers the male terminal covering 920 and is brought into close contact with the surface of the male terminal covering 920 using its restoring force. At this time, ends of the prominences (fi) of the uneven surface part T formed on the end of the male terminal covering 920 are bent and are brought into close contact with the inner surface of the protective covering 950. Simultaneously, the waterproof lubricant, which is charged in the depressions ([H]), seals gaps between the depressions ([H]) and the protective covering 950.

[195] Furthermore, compressing rings 970, 972 and 974 are fitted at predetermined positions over the outer surface of the protective covering 950, so that the protective covering 950 can be brought into contact with the male terminal covering 920 more reliably.

[196] The compressing ring 970, which is disposed adjacent to an end of the socket S, compresses the protective covering 950 and the male terminal covering 920 such that they are brought into close contact with each other, and thus serves to prevent water from permeating therebetween. The compressing ring 972, which is disposed at a medial position of the socket S, compresses part of the protective covering 950 to the uneven surface part T of the male terminal covering 920 and thus serves to maintain the uneven surface part T in the compressed state, as shown in an enlarged view of Fig. 24b. The compressing ring 974, which is disposed on a proximal end of the socket S, serves to compress and hold the female terminal 930 of the socket and the male terminal 910. [197] Therefore, outside water or moisture is prevented from permeating between the protective covering 950 and the male terminal covering 920 and reaching a contact surface 960 between the male terminal 910 and the female terminal 930.

[198] As such, the present invention can reliably prevent permeation of water or moisture using the compressing rings 970, 972 and 974, the uneven surface part T and the waterproof lubricant charged into the depressions.

[199] Here, the compressing rings 970, 972 and 974 may have structures illustrated in

Figs. 28a through 28c.

[200] Furthermore, although the electric connection device 900 shown in Fig. 24 has been described as having the single male terminal 910 and the single female terminal 930, as necessary, it may have at least two male terminals 910 and at least two female terminals 930, that is, several male and female terminals.

[201] Figs. 28a through 28c are views illustrating an example of the compression ring used in the present invention, showing an enlargement of a portion corresponding to portion A of Fig. 24a. Here, although the structure of only the compression ring designated by the reference numeral 970 of Figs. 24a and 24b is illustrated in Figs. 28a through 28c, it may be applied to the other compression rings designated by the reference numerals 972 and 974 in the same or similar manner.

[202] Referring to Fig. 28a, the compression ring 970 of Fig. 28a may be seated into a ring seating groove 952, which is formed at a predetermined position in the protective covering 950. The ring seating groove 952 serves to prevent the compression ring 970 from moving to an incorrect position.

[203] Preferably, the inner diameter of the compression ring 970 is less than the outer diameter of the protective covering 950. In particular, it is preferable that a sum of a difference between the inner diameter of the compression ring 970 and the outer diameter of the protective covering 950 (that is, a value after the outer diameter of the protective covering 950 is subtracted from the inner diameter of the compression ring 970) and double the depth of the ring seating groove 952 be zero or negative.

[204] Therefore, the compression ring 970 can reduce the inner diameter of the protective covering 950 such that the protective covering 950 is further brought into close contact with the male terminal covering 920.

[205] Referring to Fig. 28b, two or more compression rings 970, each having the same structure as that of Fig. 28a, may be provided at predetermined positions on the protective covering 950. That is, because two or more compression rings 970, each having the same structure as that of Fig. 28a, are provided, the protective covering is more strongly pushed to the male terminal covering, compared to when using the single compression ring 970. Hence, the sealing ability of the protective covering 950 can be further enhanced. [206] Referring to Fig. 28c, the compression ring 970 may be formed by a part of the protective covering 950 which is made of the same material as the protective covering at the same time but is different in thickness from the remaining part of the protective covering. In detail, because the protective covering 950 is an elastic body, depending on the thickness, the elastic force thereof varies. Therefore, if the thickness of a part of the protective covering is increased, the elastic force thereof is also increased compared to that of the remaining part. Using this principle, the compression ring 970 may be formed by increasing a thickness of a part of the protective covering 950, such that the protective covering 950 can be compressed to the male terminal covering 920.

[207] Furthermore, because the inner surface of the protective covering 950 is coated with waterproof lubricant, the protective covering 950 can be easily fitted over the male terminal covering 920, and water or moisture is prevented from permeating between the protective covering 950 and the male terminal covering 920.

[208] Here, although the electric connection device 900 shown in Figs. 24a and 24b has been described as having the single male terminal 910 and the single female terminal 930, as necessary, it may have at least two male terminals 910 and at least two female terminals 930, that is, several male and female terminals.

[209] Figs. 25a and 25b are views showing another embodiment of an electric connection device according to the present invention.

[210] This embodiment will be explained with reference to Figs. 25a and 25b, focusing on the differences between it and the embodiment of Fig. 24. In this embodiment, as shown in Fig. 25a, a male terminal covering 920 of a male terminal 910 is sectioned into a front part F, a middle part M and a rear part R. The front part F is a part of the male terminal covering, an outer diameter of which is almost equal to an inner diameter of a protective covering 950 of a socket S. The rear part R is a part of the male terminal covering, an outer diameter of which is greater than the inner diameter of the protective covering 950 of the socket S. The middle part M is a part of the male terminal covering 920, an outer diameter of which is gradually increased from the outer diameter of the front part F to the outer diameter of the rear part R.

[211] Furthermore, an uneven surface part T, which includes prominences (fi) and depressions ([H]), is provided on the front part F, that is, on an end of the male terminal covering 920 from which the male terminal 910 protrudes outwards.

[212] When the plug P is inserted into the socket S (see, Fig. 25b), because the male terminal covering 920 is constructed such that the part (that is, the front part F), which first enters the protective covering 950, has the relatively small diameter and the part (that is, the rear part R), which later enters the protective covering 950, has the relatively large diameter, the plug P can be easily inserted into the socket S. In addition, because the outer diameter of the rear part R of the male terminal covering 920 is larger than the inner diameter of the protective covering 950, the protective covering 950 can be more strongly fitted to the male terminal covering 920. Furthermore, because the protective covering 950 is brought into close contact with the male terminal covering by its restoring force when it is fitted over the male terminal covering 920, ends of the prominences (fi) of the uneven surface part T formed on the front part F, that is, on the end of the male terminal covering 920 are bent and are brought into close contact with the inner surface of the protective covering 950. Simultaneously, waterproof lubricant, which is charged in the depressions ([H]), seals gaps defined between the depressions ([H]) and the protective covering 950.

[213] Figs. 26a and 26b are views showing a further embodiment of an electric connection device according to the present invention.

[214] This embodiment will be explained with reference to Figs. 26a and 26b, focusing on the differences between it and the embodiments of Figs. 24 and 25. In this embodiment, as shown in Figs. 26a and 26b, a covering depression 922 is formed at a predetermined position around a rear part R of the male terminal covering. (Here, the male terminal covering 920 of Figs. 24a and 24b having a covering depression 922 may substitute for the male terminal covering 920 of this embodiment.)

[215] Preferably, the covering depression 922 is formed at a position corresponding to the position, at which the compression ring 970 is disposed. Here, the compression ring 970 may have either one of the structures of Figs. 28a through 28c.

[216] In the same manner, because the male terminal covering 920 is constructed such that the part (that is, the front part F), which first enters the protective covering 950 when the plug P is inserted into the socket S, has the relatively small diameter and the part (that is, the rear part R), which later enters the protective covering 950, has the relatively large diameter, the plug P can be easily inserted into the socket S. In addition, because the outer diameter of the rear part R of the male terminal covering 920 is larger than the inner diameter of the protective covering 950, the protective covering 950 can be more strongly compressed to the male terminal covering 920.

[217] Furthermore, because the compressing ring 970 is disposed at the position corresponding to the covering depression 922, the plug P is prevented from being undesirably removed from the socket S and, in addition, it is able to solve a problem, in which, with the passage of time for which the protective covering 950 and the compression ring 970 are fitted over the male terminal covering 920 having the diameter larger than the inner diameters thereof, the restoring force of the protective covering 950 and the compression ring 970 is reduced and the sealing ability is thus reduced.

[218] Therefore, compared to the embodiment of Figs. 25a and 25b, this embodiment can more reliably prevent outside water or moisture from permeating between the protective covering 950 and the male terminal covering 920 and reaching a contact surface 260 between the male terminal 910 and the female terminal 930.

[219] Figs. 27a and 27b are views showing yet another embodiment of an electric connection device according to the present invention.

[220] This embodiment will be explained with reference to Figs. 27a and 27b, focusing on the differences between it and the embodiments of Figs. 24 and 26. In this embodiment, an uneven surface part T, which includes prominences (fi) and depressions ([H]), is provided on an end of the male terminal covering 920 from which the male terminal 910 protrudes outwards. The uneven surface part T has a shape such that the diameter thereof is increased from an end thereof, that is, from the end adjacent to the protruded male terminal 910 to the other end.

[221] Here, the associated part of the protective covering 950 is reduced in thickness in a direction away from a female terminal 930. In other words, the protective covering 950 is constructed such that the part corresponding to the uneven surface part T of the plug P is gradually reduced in thickness and the remaining part maintains a constant thickness (in other words, a space, into which the plug P is inserted, is gradually increased in diameter and the remaining portion thereof maintains a constant diameter).

[222] Because the protective covering 950 has the inner diameter equal to or less than the outer diameter of the male terminal covering 920 of the plug P, when the plug P is inserted into the socket S (see, Fig. 27b), the protective covering 950 covers the male terminal covering 920 and is brought into close contact with the male terminal covering by its restoring force. Thus, ends of the prominences (fi) of the uneven surface part T formed on the end of the male terminal covering 920 are bent and are brought into close contact with the inner surface of the protective covering 950. Simultaneously, waterproof lubricant, which is charged in the depressions ([H]), seals gaps defined between the depressions ([H]) and the protective covering 950.

[223] Particularly, the uneven surface part T has the shape such that the diameter thereof is increased in one direction, and the protective covering 950 of the socket S has the shape such that the space, defined by the part thereof corresponding to the uneven surface part, is increased in diameter. Therefore, when the plug P is inserted into the socket S, the prominences (fi) of the uneven surface part T can be easily bent, and waterproof lubricant, which is charged in the depressions ([H]), can efficiently seal gaps defined between the depressions ([H]) and the protective covering 950.

[224] Here, a compressing ring 970, which is disposed adjacent to an end of the socket S, compresses the protective covering 950 and the male terminal covering 920 such that they are brought into close contact with each other, and thus serves to prevent water from permeating therebetween. A compressing ring 972, which is disposed at a medial position of the socket S, compresses part of the protective covering 950 to the uneven surface part T of the male terminal covering 920 and thus serves to maintain the uneven surface part T in the compressed state, as shown in an enlarged view of Fig. 27b. A compressing ring 974, which is disposed on a proximal end of the socket S, serves to compress and hold the female terminal 930 of the socket and the male terminal 910.

[225] Fig. 29 is a perspective view of another embodiment of a hot floor panel according to the present invention. Fig. 29a is a perspective view, and Fig. 29b is a front view. As shown in the drawings, in this embodiment, a ceramic plate 10 includes a base plate 111, a heat transfer adhesive layer 117, an acupressure part, which forms a top layer and has large protrusions 113 and small protrusions 115, and tiles 112. This ceramic plate 10 makes it possible for a user to make use of acupressure protrusions, and also serves as a critical part of the hot floor panel. For this, several protrusions are provided on the ceramic plate.

[226] The base plate 111 may have the same construction as that of the ceramic plate 10 illustrated in the prior embodiments. The tiles 112, and the large protrusions 113 and the small protrusions 115, which serve as the acupressure part, are adhered on the base plate by the heat transfer adhesive layer 117. Here, the base plate of this embodiment may have a thickness less than that of the ceramic plates, used in the prior embodiments, to reduce the thickness of the entire ceramic plate.

[227] The heat transfer adhesive layer 117 serves to transfer heat from a heating element

20 to the large protrusions 113, the small protrusions 115 and the tiles 112 through the base plate 111. The heat transfer adhesive layer 117 may be manufactured by melting thermosetting resin, such as epoxy resin, phenol resin, etc., which is not melt even at a temperature of 8O⁰C, or a bonding agent, which is heat-resistant. The heat transfer adhesive layer 117 is preferably made of epoxy resin such that it can be firmly adhered to the ceramic plate 10. In particular, it is preferable that epoxy resin having superior adhesive strength to stone or ceramic material be used.

[228] The ceramic plate 10 is a part which directly contacts the feet of the user, and to which load and impact is directly applied. The size of each tile of the ceramic plate may be changed depending on the material of the tile. Preferably, it is appropriate to use relatively small tiles of 25x25mm, which are commonly available on the market. As such, the size of the tile is determined by the material thereof.

[229] Furthermore, the tiles 112, and the large protrusions 113 and the small protrusions

115, which serve as the acupressure part, must have appropriate heat conductivity to prevent injury such as burn injury to the user. Furthermore, preferably, they are made of material which radiates far infrared rays to promote the health of the user. To achieve the above-mentioned purposes, the large protrusions 113 and the small protrusions 115, which serve as the acupressure part, are preferably made of substances such as pea gravel, which is granular stone that has relatively high density of 2.4 to 2.8 specific gravity and has far- infrared radiating efficiency. As such, because such pea gravel has a size appropriate for acupressure, it can be used as the acupressure part. Furthermore, the large protrusions and the small protrusions may be made of jade or natural stones, which have high far-infrared radiating efficiency. In addition, the acupressure part may comprise acupressure balls that are manufactured by mixing and forming ceramic, germanium and elvan granules, which radiate far-infrared rays and anions and are able to conduct heat, into a ball shape.

[230] Each large protrusion 113 protrudes from the tiles 112 by approximately 5mm to

10mm, such that, when the foot of the user is placed thereon, appropriate acupressure force is applied to the foot.

[231] Meanwhile, after the process of fixing the acupressure part 113, which radiates far infrared rays, has been completed, thermoplastic resin, such as PVC, PE(LDPE, HDPE), PP, PS, ABS, PA(polyamide; nylon), PET, etc., or thermosetting transparent synthetic resin, such as phenol resin, urea resin, epoxy resin, etc, is applied to the surface of the ceramic plate 110, thus forming a surface treatment layer for finishing treatment. Of course, the surface treatment layer may be used only when it is necessary. In other words, the surface treatment of the ceramic plate may be realized by itself.

[232] In this embodiment having the above-mentioned construction, heat energy generated by the heating element 20 is transferred to the tiles 112, the large protrusions 113 and the small protrusions 115. Here, because the tiles 112 are made of ceramic, they mostly convert heat energy into far-infrared waves. In addition, because the acupressure part, which is made of material such as pea gravel or jade and serves as the far infrared ray radiating element, is a granular stone having high density, it has relatively high far- infrared radiating efficiency. Therefore, a large amount of far infrared rays can be radiated onto the feet of the user.

[233] Furthermore, when the user places his/her foot onto the large protrusion 113, which is made of material, such as jade or pea gravel, and serves as the far- infrared ray radiating element, the large protrusion 113 presses the foot's sole by a depth ranging from 5mm to 10mm and radiates far- infrared rays thereto. Then, the far- infrared rays stimulate capillary vessels of the foot and thus promote blood circulation and cell creation, thereby accelerating the metabolism of the user's body.

[234] Moreover, in the present invention, the acupressure part can press several portions of the foot sole, so that the acupressure effect is increased. In particular, because nerves are concentrated in the foot sole, the acupressure part can appropriately stimulate acupuncture points, which are connected to the organs of the user's body.

[235] Meanwhile, because the large protrusions 113 directly contact and are adhered to the heat transfer adhesive layer 117, it is preferable that a separate bonding agent such as silicone be applied to contact surfaces therebetween. Such bonding agent can be effectively used to prevent the acupressure part from being undesirably removed by contraction and expansion due to a change in temperature. In addition, it is preferable that the small protrusions 115 be previously adhered or coupled to the tiles 112. The large protrusions 113 and the small protrusions 115, which serve as the far infrared ray radiating elements, may be made of the same or similar materials. In this embodiment, the several large protrusions 113, which are used for acupressure of the foot sole, are preferably provided to correspond to the shape of the foot sole. Here, the large protrusions 113 are preferably disposed at dispersed positions, rather than at positions adjacent to each other, such that they can evenly press several portions of the foot sole.

[236] Fig. 30 is a front sectional view corresponding to Fig. 29, but illustrating of another formation of large protrusions 113 and small protrusions 115 on tiles 112 of a ceramic plate 10. In this case, the large protrusions 113 and the small protrusions 115 are adhered to the upper surface of the tiles 112 by an adhesive layer 119 formed by material such as silicone. For this, the tiles 112 are machined or formed by molding, such that seats for adhesion of the protrusions are formed in the upper surfaces of the tiles 112. The general construction of this embodiment other than the tiles is the same as or similar to the other hot floor panels.

[237] In the embodiments of Figs. 29 and 30, it is preferable that the large protrusions 113 be alternately arranged with respect to the tiles 112. Furthermore, each of the tiles 112 may be used without having the small protrusion 115. In addition, in place of the tiles 112, planar natural stones or inorganic matter, which can generate far infrared rays, may be used. Moreover, the arrangement of the large protrusions 113 in the tiles 112 may be variously modified. Industrial Applicability

[238] The hot floor panel according to the present invention can be easily constructed and used in places, such as dwellings, offices and hotels, etc., in which heating is required.

[239] Furthermore, the hot floor panel of the present invention can solve the problems of an electric leakage and a short circuit, thus being suitable for a panel for heating a room.

Claims

[ 1 ] A hot floor panel, comprising: a ceramic plate including an artificial stone, a tile or a natural stone plate and radiating far infrared rays; a heating element placed under the ceramic plate and having a linear or planar shape; and an adiabatic plate placed under the heating element and having a support member supporting the ceramic plate and the heating element, and an adiabatic part performing heat insulation and absorbing impacts, the support member and the adiabatic part forming a single layer.

[2] The hot floor panel according to claim 1, wherein the heating element comprises a linear or planar type heating element, or a heating element having a thin layer structure provided with a mesh or a net type heating part, wherein the heating element is attached to a lower surface of the ceramic plate, or the heating part is directly printed or attached to the lower surface of the ceramic plate to perform a heating function.

[3] The hot floor panel according to claim 1 or 2, wherein the heating element is waterproofed with epoxy, silicone or cement molding agent, or a lower surface of the adiabatic plate or the lower surface of the ceramic plate or both are adhered to the heating element using epoxy, silicone or cement molding agent.

[4] The hot floor panel according to any one of claims 1 through 3, wherein a contact part between the heating element and a wire is waterproofed with the support member.

[5] The hot floor panel according to any one of claims 1 through 4, wherein the ceramic plate and the support member are integrated with each other.

[6] The hot floor panel according to any one of claims 1 through 5, wherein the adiabatic part comprises: a receiving groove to receive at least one of the heating element, the wire for the heating element, a control or measurement device including a temperature control device, or a part pertaining to the heating element; and a plurality of support member receiving holes formed at predetermined positions for installation of the support members in the adiabatic plate such that the adiabatic plate withstands an external load or impact.

[7] The hot floor panel according to any one of claims 1 through 6, wherein the adiabatic plate is made of polystyrene foam, isopink or foamed adiabatic material.

[8] The hot floor panel according to claim 6 or 7, wherein a fastening groove, having a depth greater than a depth of the receiving groove, is formed in the receiving grooves in a direction crossing the receiving groove to fasten the heating element.

[9] The hot floor panel according to any one of claims 6 through 8, wherein the adiabatic part further comprises a support body inserted into each of the receiving holes.

[10] The hot floor panel according to claim 9, wherein the support body comprises an elastic part having high elasticity, and a support part having a strength higher than the elastic part.

[11] The hot floor panel according to claim 9 or 10, wherein the support body comprises a spring, or a spring and a stop rod to limit a deformation of the spring in a longitudinal direction.

[12] The hot floor panel according to any one of claims 1 through 11, wherein the ceramic plate comprise a plate body, and a coupling protrusion and a coupling seat, which are provided on edges of the plate body, the coupling protrusion has a predetermined thickness from a lower surface of the ceramic plate, and has a predetermined length, to which the coupling protrusion protrudes from the plate body outwards, and the coupling seat has a predetermined height from the lower surface of the ceramic plate, and has a predetermined depth, to which the coupling seat is recessed from the associated edge of the plate body inwards.

[13] The hot floor panel according to claim 12, wherein the protruded length of the coupling protrusion is greater than the recessed depth of the coupling seat.

[14] The hot floor panel according to claim 12 or 13, wherein the coupling protrusion or the coupling seat has a trapezoidal shape, which is reduced in width in a direction away from the edge of the plate body.

[15] The hot floor panel according to claims 1 through 14, wherein a soft floor sheet is attached to the ceramic plate.

[16] The hot floor panel according to claim 15, wherein the soft floor sheet, having a stiffness lower than a stiffness of the ceramic plate, is attached to an upper surface of the ceramic plate, and a coupling protrusion and a preliminary coupling seat are formed on at least one of the ceramic plate and the soft floor sheet, wherein the preliminary coupling seat forms a coupling seat, corresponding to the coupling protrusion, by coupling of the soft floor sheet and the hard floor sheet.

[17] The hot floor panel according to claim 15 or 16, wherein the soft floor sheet comprises a wood floor sheet, including a natural wood sheet, an artificial wood sheet and a laminate flooring sheet, a chemical floor sheet, a paper floor sheet or a decorative tile.

[18] The hot floor panel according to any one of claims 12 through 17, wherein the coupling protrusion and the coupling seat comprise one pair or two pairs of coupling protrusions and coupling seats.

[19] The hot floor panel according to any one of claims 12 through 18, wherein the coupling protrusion and the coupling seat are formed in the ceramic plate, and a paint or organic matter is applied to the coupling protrusion and the coupling seat to prevent damage to the ceramic plate attributable to contact between the adjacent ceramic plates.

[20] The hot floor panel according to any one of claims 15 through 19, wherein the ceramic plate and the soft floor sheet are adhered to each other using epoxy or silicone, or are attached to each other by thermocompression bonding.

[21] The hot floor panel according to any one of claims 15 through 20, wherein the soft floor sheet has a thickness ranging from 0.5 mm to 5 mm.

[22] The hot floor panel according to any one of claims 1 through 11, wherein the heating panel including the adiabatic part and the support member is coupled to the ceramic plate such that two edges of the hot floor panel protrude outwards therefrom to form protrusion parts and two remaining edges define receiving parts corresponding to the protrusion parts, so that, when hot floor panels are coupled to each other, the protrusion parts close spaces defined between the ceramic plate and other ceramic plates.

[23] The hot floor panel according to claim 22, wherein the heating panel including the adiabatic part and the support member has a shape equal to a shape of the ceramic plate, and the heating panel and the ceramic plate are coupled into a misaligned shape, thus forming the protrusion parts and the receiving parts.

[24] The hot floor panel according to claim 22 or 23, wherein the heating panel including the adiabatic part and the support member is larger than the ceramic plate, so that, when the hot floor panel is coupled to another hot floor panel, a joint spacing is defined between the ceramic plates by contact between the heating panels.

[25] The hot floor panel according to claim 22 or 24, wherein the heating panel including the adiabatic part and the support member has the coupling protrusion, which is a protruding part that protrudes outwards based on an edge of the ceramic plate, and the coupling seat, which is a receiving part recessed based on an edge of the ceramic plate, and a width of each of the coupling protrusion and the coupling seat is less than a length of a corresponding edge of the heating panel.

[26] The hot floor panel according to any one of claims 22 through 25, wherein an electric wiring space for the heating element is defined in the receiving part.

[27] The hot floor panel according to any one of claims 1 through 19 and 22 through

26, wherein the ceramic plate comprises: a base plate; a heat transfer adhesive layer provided on the base plate; and a tile and an acupressure part adhered to the heat transfer adhesive layer, so that the ceramic plate has an acupressure function.

[28] The hot floor panel according to claim 27, wherein the acupressure part comprises a large protrusion and a small protrusion and is adhered to the heat transfer adhesive layer or the tile.

[29] The hot floor panel according to claim 27 or 28, wherein the acupressure part is adhered to the heat transfer adhesive layer or the tile using a bonding agent including silicone.

[30] The hot floor panel according to any one of claims 1 through 29, wherein the support member is provided in the adiabatic part to form one layer or is formed to have a shape such that support member covers the entire adiabatic part.

[31] The hot floor panel according to any one of claims 1 through 29, wherein the support member is formed by hardening liquefied material, including adiabatic castable or cement molding agent having an adiabatic ability, thus having a predetermined degree of stiffness.

[32] The hot floor panel according to any one of claims 1 through 29, wherein the adiabatic part further comprises a coating layer made of adiabatic castable material or cement molding agent, or the coating layer is integrated with the support member.

[33] The hot floor panel according to any one of claims 1 through 32, further comprising an electric connection device including: a plug, having a male terminal, a male terminal covering, which covers the male terminal, and an uneven surface part provided on an end of the male terminal covering; and a socket, having a female terminal corresponding to the male terminal, a female terminal covering, which covers the female terminal, and a protective covering extending a predetermined length from the female terminal covering to cover the male terminal covering, with a compression ring fitted at a predetermined position over a surface of the protective covering.

[34] The hot floor panel according to claim 34, wherein the uneven surface part is filled with waterproof lubricant.

[35] The hot floor panel according to claim 33 or 34, wherein prominences of the uneven surface part are increased in diameter in a direction away from the male terminal.

[36] The hot floor panel according to any one of claims 33 through 35, wherein an inner surface of the protective covering or/and a surface of the male terminal covering are coated with waterproof lubricant.