Background Art Generally, a seat is comprised of a seat portion and a support frame which supports the seat portion. When the seat portion is made of a general non-flame-retardant material rather than a flame-retardant material, the seat portion is vulnerable to burning when a fire occurs so that the burning also makes the fire expand to an adjacent area, and is vulnerable to the generation of toxic gases which necessarily cause to disastrous accidents such as loss of human life and damages to personal properties.

In an effort to solve the above problems in the prior art, a flame- retardant pack seat for railroad vehicles and a noninflammable seat cushion for seat have been suggested in Korean Registered Utility Model Nos. 20- 0327642 (hereinafter'642 Registered UM) and 20-0321818 (hereinafter'818 Registered UM), respectively.

In a flame-retardant packed seat for railroad vehicles disclosed in '642 Registered UM, a back plate and a sitting plate for a seat member are comprised of a flame-retardant base layer, an upper and a lower glass fiber layers covering the flame-retardant base layer therebetween, and an upper and a lower outer layers having some shapes covering the upper and the lower glass-fiber layers therebetween. However, the respective layers comprising the seat member are required to use an impregnation base which is flame-retardant treated in an impregnation liquid of flame-retardant resin

so that fabrication processes of the seat member become extremely complicated and therefore the productivity thereof is lowered.

Also, a noninflammable seat cushion for a seat disclosed in'818 Registered UM is comprised of a steel net, a buffer having a flame-retardant property, a first base plate, a first fiber glass, a second fiber glass, and a coating member, etc. in the seat cushion which is a component of the seat.

However, the noninflammable seat cushion is made by stacking the steel net, a plurality of fiber glasses, and the buffer in a multiple layer so that the structure of the seat cushion is extremely complicated and the fabrication processes of stacking the respective layers in a multiple layer are cumbersome and complicated and therefore the productivity thereof is lowered.

Disclosure of Invention One object of the present invention is to solve the prior art problems by providing a flame-retardant seat which minimizes loss of human life and damages to personal properties due to a fire, by maximizing a flame- retardant property of a seat when a fire occurs at a place where such seat is equipped with and therefore by minimizing the expansion of the fire or the generation of toxic gases.

Another object of the present invention is to provide a flame- retardant seat having a simple structured seat member thereof and therefore enhance the productivity of the seat.

To achieve the above objects, a flame-retardant seat according to the present invention comprises a) a seat portion comprising i) a silicone foamed member with a predetermined thickness; ii) a plate member placed under the silicone foamed member; and iii) an outer cover encapsulating the silicone foamed member, wherein the outer cover is at least partially connected to the plate member inside and under the plate member; b) a support frame for supporting the seat portion; and c) a connection means for fixedly securing the seat portion to the support frame.

Further, the silicone foamed member used for a flame-retardant seat of the present invention is preferably made by cross-linking of a main component (A) being made of silicone polymer having at least two double bonds per molecule with a curing material (B) including polyorganosiloxane.

Further, the silicone foamed member used for a flame-retardant seat of the present invention has a mixing combination of the main component (A) of 100 by weight with the curing material (B) of 60 to 150 by weight.

Further, the connection means used for a flame-retardant seat of the present invention may use a fastener for separating the seat portion from the support frame and for connecting the seat portion to the support frame, where the fastener comprises a male member which is inserted into a through-hole of the plate member disposed under the seat portion so that the male member is fixed to the plate member; and a female member which is inserted into a through-hole formed on the upper surface of the support frame so that the female member is fixed to the support frame.

Further, the flame-retardant seat used for a flame-retardant seat of the present invention preferably further includes at least one layer of a cushion member which is inserted between the seat portion and the support frame.

Brief Description of the Drawings Fig. 1 is a whole perspective view in accordance with the present invention.

Fig. 2 is an exploded perspective view of a flame-retardant seat in accordance with the present invention.

Fig. 3 is a partially cross-sectional view of a seat portion of a flame- retardant seat in accordance with the present invention.

Fig. 4 is a perspective view of a plate member applied to a seat portion of a flame-retardant seat in accordance with the present invention.

Fig. 5a is a perspective view of a male fastener in accordance with the present invention.

Fig. 5b is a perspective view of a female fastener in accordance with the present invention.

Fig. 6 is a cross-sectional view showing a state of engagement of a seat portion with a support frame by a fastener in a flame-retardant seat in accordance with the present invention.

Fig. 7 is an exploded perspective view of another embodiment of a flame-retardant seat in accordance with the present invention.

Best Mode for Carrying Out the Invention Hereinafter, a flame-retardant seat in accordance with preferred embodiments of the present invention is described in more detail with reference to the appended drawings.

As illustrated in Figs. 1 and 2, a flame-retardant seat 1 in accordance with the present invention comprises a seat portion 10; a support frame 20 for supporting the seat portion 10; and a connection means for fixedly securing the seat portion 10 to the support frame 20. In this specification, the term"seat"refers to"a chair"and"seat portion"refers to"a part of a chair for a user to be seated,"as illustrated in Fig. 1.

As illustrated in Figs. 2 and 3, the seat portion 10 comprises a silicone foamed member 11 with a predetermined thickness; a plate member 12 placed under the silicone foamed member 11; and an outer cover 13 encapsulating the silicone foamed member 11, wherein the outer cover 13 is at least partially connected to the plate member 12 inside and under the plate member 12.

The silicone foamed member 11 is made by cross-linking of a main component (A) being made of silicone polymer having at least two double bonds per molecule with a curing material (B) including polyorganosiloxane.

The present invention is preferable to have a mixing combination of the main component (A) of 100 by weight with the curing material (B) of 60 to

150 by weight. If the curing material (B) is added below 60 by weight, the hardness of the silicone foamed member becomes too low and thus the cushion function of the silicone foamed member is significantly lowered as a cushion member which requires repulsive force to a certain constant level.

Nor a proper curing reaction occurs for the silicone foamed member and thus the silicone foamed member cannot be formed in a desired shape.

Further, if the curing material (B) is added above 150 by weight, it is also difficult to form the silicone foamed member as a desired shape.

In the meanwhile, various characteristic values are given to determine a proper usability of the cushion member which is used for a flame-retardant seat. Among them, the most important characteristic values are an oxygen index (indicated as"Ol"), a specific optical density of smoke or smoke density (indicated as"Ds"), a resistance to spread of surface flame (indicated as"class 1,2, 3 and 4"), and a toxic gas index (indicated as"R").

Of is a numerical value of content of remaining oxygen after burning a constant amount of a test subject for a constant time at a specific space. It means that the higher the numerical value is, the lower oxygen is consumed when burning a test subject. That is, the higher value of Of means that it is difficult to burn a test subject and therefore it is determined that such test subject has a good flame-retardant property. Ds is a numerical value of the degree of darkening a view due to a smoke caused when burning a test subject at a specific space, under certain circumstances. It means that the higher the numerical value of Ds is, the more smoke is generated when burning a test subject. Therefore, the lower value of Ds is considered that a test subject has a good flame-retardant property. R is a reference value to determine the degree of toxicity when burning a test subject under certain circumstances. That is, R is a predetermined numerical value based on the generation or not of various toxic gases harmful to a human body, and its content, if any. There are various test standards to measure the characteristic values illustrated above and the following are the most reliable test standards which are currently and widely accepted, respectively : ISO

4589-2 for Ol ; BS 6853 D8.5 (Great Britain) and ASTM E662 (USA) for Ds; BS 476-7 (Great Britain) for a resistance to spread of surface flame ; and BS 6853. B2 (Great Britain) for R.

The silicone foamed member 11 in accordance with the present invention may be molded by mixing the main component (A) and the curing material (B) in the ratio of 1: 1 by volume ; injecting the mixed material in a mold the inner space of which is sized of 430mm x 430mm x 2cm; and holding the mixed material for 20 minutes at a temperature of 20 to 30 °C.

By testing the molded silicone foamed member in accordance with the internationally recognized test standards described above, the measured values turn out that Ol is 36%; Ds in flaming mode for 1.5 min. is 4.5 or less; R is 0.18 or less ; and a resistance to spread of surface flame is class 2. All these measured values are substantially superior compared to the characteristic values measured from polyurethane foam which is widely used for a cushion member in known seats, such as Ol of 17.6 to 20.2 ; Ds (1.5 <BR> <BR> min. ) of 50.77 to 187.65 ; and R of 2.67 to 4.17. In the above comparison test, the polyurethane foam is manufactured from polyol and isocyanate by using a generally used method and the test result relating to the polyurethane foam is obtained by testing polyurethane manufactured from a high-pressure foaming device having an ejection pressure of 150 bars.

As illustrated in Fig. 3, the plate member 12 is placed under the silicone foamed member 11. The plate member 12 is used as a connection intermediary for connecting the silicone foamed member 11 to the support frame 20 securely, because the silicone foamed member 11 having a predetermined thickness cannot be directly joined to the support frame 20.

The plate member 12 is selected from a stainless steel plate when corrosion- resistance and durability are required, or an aluminum plate or flame- retardant plastic when lightweight and anti-oxidation are required, etc., depending on the circumstances equipping a flame-retardant seat. Further, one or more through-holes 14, as illustrated in Fig. 4, are formed on the plate member 12 in order for the plate member 12 to be possibly separated

or connected by a connection means such as a fastener (F) which will be described later. The outer cover 13 is for covering the silicone foamed member 11. As illustrated in Fig. 3, the outer cover 13 encapsulates the silicone foamed member 11 and the plate member 12 as a whole, while being at least partially connected to the plate member 12 inside and under the plate member 12. Further, the outer cover 13 is made of cloth which is flame-retardant treated by impregnating, applying or spraying a flame- retardant material into the surface of the outer cover 13.

As described above, the seat portion 10 comprised of the silicone foamed member 11, the plate member 12, and the outer cover 13 has a very simple structure so that the manufacturing processes are simplified and therefore productivity thereof is enhanced, and accomplishes a very superior effect in terms of a flame-retardant property because the respective components each are comprised of a material having a flame-retardant property and non-inflammability.

In the meanwhile, the support frame 20 is a frame for supporting the seat portion 10 and, as illustrated in Fig. 1, comprises a lower frame 20a fixed along a wall or a bottom part at a place where a flame-retardant seat is equipped; and a upper frame 20b which is disposed on the lower frame 20a.

The support frame 20 can be fabricated in a variety of types by changing a shape thereof into different shapes, respectively, depending on the circumstances and usage thereof, e. g. , by changing the lower frame 20a and the upper frame 20b into an integrated frame as a one body. Further, as illustrated in Fig. 2, one or more through-holes 21 are formed respectively at the positions of the support frame 20 which correspond to the positions of the plate member 12 which functions as a lower surface of the seat portion 10 on which the one or more through-holes 14 are formed, in order for the support frame 20 to be possibly separated or connected by a connection means such as a fastener (F) which will be described later.

The connection means described above is a means for fixedly connecting the seat portion 10 to the support frame 20 by employing a

bolting method to securely connect both components or a fastener (F) for separating or connecting both components, etc.

The removable fastener (F) attaches the seat portion 10 to the support frame 20 for possibly making a mutual separation and connection.

The fastener (F) comprises a male member 30a which is inserted and fixed into a through-hole 14 of the plate member 12 disposed under the seat portion 10 as illustrated in Fig. 5a, and a female member 40 which is inserted and fixed into a through-hole 21 formed on the upper surface of the support frame 20 as illustrated in Fig. 5b.

The male member 30 further comprises a head 31; an axle 32 extended from the bottom surface of the head 31; and one or more engaging protrusions 33 for fixing formed on an outer circumference of the axle 32.

The female member 40 comprises a hollow body 41 having a predetermined height; and a head 42 protrudently formed on an outer surface of an upper end of the body 41, wherein one or more cleavages 43 are formed in the body 41 in order to for them be shrinkable by self-resilient force thereof when the body 41 is inserted into the through-hole 14 formed on the seat portion 10 by pressing, and wherein one or more engaging grooves 44 to be engaging combined with the engaging protrusions 33 of the male member 30 are formed in an inner periphery surface of the body 41.

As described above, when combining the seat portion 10 with the support frame 20 by using the male member 30 and the female member 40, the head 31 of the male member 30 is first inserted into the through-hole 14 formed on the seat portion 10. Thereafter, the body 41 of the female member 40 is inserted into the through-hole 21 formed on the support frame 20 and then the female member 40 is pressed. In this situation, the male member 39 and the female member 40 are fixed in the seat portion 10 and the support frame 20, respectively, and the preparation for combining the seat portion 10 with the support frame 20 is completed. Then, as force is exerted on an upper surface of the seat portion 10 to be pressed toward the support frame 20 after matching the axle 32 of the male member 30 with the hollows

formed in the body 41 of the female member 40, the engaging protrusions 33 formed on the axle 32 of the male member 30 are engaged with the engaging grooves 44 of the female member 40 and therefore the combination of the seat portion 10 with the support frame 20 is simply completed as illustrated in Fig. 6.

Further, in case that there arises an occasion to separate the seat portion 10 from the support frame 20, certain force is exerted on the seat portion 10 in a direction vertical to the surface of the seat portion 10, and the engaging protrusions 33 of the seat portion 10 is removed from the engaging grooves 44 of the support frame 20 so that the seat portion 10 is easily separated from the support frame 20.

In the meanwhile, unlike the embodiment described above, it is more preferable to insert a cushion member 50 made of a flame-retardant material between the seat portion 10 and the support frame 20 in the flame-retardant seat in accordance with the present invention, as illustrated in Fig. 7.

The cushion member 50 is to protect the propagation of fire flame from the under support frame 20 to the upper seat portion 10 when a fire occurs, and performs a cushion function to mitigate noises and vibrations which may be caused from the direct contact of the seat portion 10 with the support frame 20. The cushion member 50 may be made of silicone foamed material which is the same as that of the silicone foamed member 11 inserted in the seat portion 10.

A through-hole 14 is formed on the cushion member 50 in order that the axle 32 of the male member 30 of the fastener (F) which is used for combining the seat portion 10 with the frame member 20 is easily inserted into the hollow formed in the body 41 of the female member 40 of the support frame 20.

Industrial AppGicability The flame-retardant seat in accordance with the present invention can maximize a flame-retardant property of a seat when a fire occurs at a

place where such seat is equipped with, and minimize the expansion of the fire or the generation of smoke and toxic gases so that loss of human life and damages to personal properties due to a fire are minimized. Also, a simple structured seat portion of a seat is possibly fabricated so that productivity of seat is significantly enhanced.

As various modifications could be made in the constructions and method herein described and illustrated without departing from the scope of the present invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.