Patent Description:
A child car safety seat provides a seating space with a suitable size for a child in a car ride, and buffering structures are disposed on surrounding walls of the child car safety seat which are in contact with the child to serve as a buffer during a crash so that possibility of injury to the child might be reduced. The buffering structure can be fixed to a main body of the safety seat and covered under a seat cloth, or the buffering structure can be disposed on the seat cloth. For example, a supporting cushion or a headrest is often mounted to the upper backrest portion of an infant basket safety seat for supporting and protecting an infant's head, and the buffering structure can be disposed inside the supporting cushion for improving safety.

Conventional buffering structures are foams made of expanded polypropylene (EPP), expanded polystyrene (EPS) or expandable polyethylene (EPE) and in a shape of a plate or a block. The foams have good impact absorbing capacity for effective buffering. However, the foams are also flammable and have a higher combustion rate upon ignition, which is unsafe for application. Alternatively, the foams in the safety seat can be replaced by a flame-retardant material, but the hardness of the flame-retardant material reduces the impact absorbing capacity and comfort of the safety seat.

<CIT> teaches a fire resistant thermoplastic composite material which may be shaped as a cover sheet for car seat liners. Sheets of said composite material may be formed from a core, to which fire retardant materials may be added or alternatively, a backing layer fused to said core may be provided with fire resistant materials.

<CIT> teaches to a gusset for a mattress wherein a fire-blocking layer <NUM> can be arranged above a cushioning layer <NUM> and below a cover layer <NUM>. The layers are stitched together to form a composite material.

Therefore, it is necessary to develop a supporting cushion apparatus that combines buffering capacity and flame-retardant effect so as to improve safety and comfort of the safety seat.

This in mind, the present invention aims at providing a supporting cushion apparatus having a buffering structure which combines buffering capacity and flame-retardant effect, and a safety seat having the supporting cushion apparatus.

This is achieved by a supporting cushion apparatus and a safety seat therewith according to claims <NUM> and <NUM>. The dependent claims pertain to corresponding further developments and improvements.

As will be seen more clearly from the detailed description following below, the claimed supporting cushion comprises a buffering structure including a buffering plate and a fireproof plate combined with the buffering plate. A combustion rate of the fireproof plate is lower than a combustion rate of the buffering plate. The apparatus comprises a covering member, the fireproof buffering structure being accommodated inside a covering pocket disposed on at least one of the head supporting portion and two flanking portions connected with two sides of a head supporting portion of the covering member.

Preferably, the buffering plate is a foam plate.

Specifically, a density of the foam plate is substantially between <NUM>/m3 and <NUM>/m3.

Preferably, the fireproof plate is made of at least one of polyethylene (PE), polypropylene (PP), expanded polystyrene (EPS), expanded polypropylene (EPP), expanded polystyrene (EPO), fireproof foam, ethylene-vinylacetate copolymer (EVA), and botanical cotton.

Specifically, the botanical cotton is corn cotton.

Preferably, a thickness of the fireproof buffering structure is substantially smaller than <NUM>.

Specifically, the thickness of the fireproof buffering structure is substantially equal to <NUM>.

Preferably, the fireproof buffering structure comprises a plurality of fireproof plates. At least part of the plurality of fireproof plates are made of different materials.

Preferably, a shape of the fireproof plate corresponds to a shape of the buffering plate, and the fireproof plate is attached to a front surface of the buffering plate.

Specifically, the fireproof buffering structure comprises two buffering plates respectively attached to a front surface of the fireproof plate and a rear surface of the fireproof plate.

Specifically, the fireproof buffering structure further comprises a first auxiliary fireproof plate attached to a surface of the two buffering plates away from the fireproof plate.

Specifically, the fireproof buffering structure further comprises a second auxiliary fireproof plate. The first auxiliary fireproof plate and the second auxiliary fireproof plate are respectively attached to two surfaces of the two buffering plates away from the fireproof plate.

Specifically, the fireproof buffering structure further comprises a first auxiliary fireproof plate. The fireproof plate and the first auxiliary fireproof plate are respectively attached to a front surface of the buffering plate and a rear surface of the buffering plate.

Specifically, the fireproof buffering structure comprises three buffering plates. A surface of the fireproof plate and a surface of the first auxiliary fireproof plate are respectively attached to a front surface and a rear surface of one of the three buffering plates, and the other two of the three buffering plates are respectively attached to an another surface of the fireproof plate and an another surface of the first auxiliary fireproof plate.

Specifically, the fireproof buffering structure further comprises a first auxiliary fireproof plate. A surface of the fireproof plate is attached to the buffering plate, and the first auxiliary fireproof plate is attached to an another surface of the fireproof plate.

Specifically, the fireproof buffering structure comprises two buffering plates. the fireproof plate is attached to one of the two buffering plates. A surface of the first auxiliary fireproof plate being attached to the fireproof plate, and the other one of the two buffering plates is attached to an another surface of the first auxiliary fireproof plate.

Specifically, the fireproof buffering structure further comprises a second auxiliary fireproof plate. The first auxiliary fireproof plate and the fireproof plate are attached between opposite surfaces of the two buffering plates facing towards each other, and the second auxiliary fireproof plate is attached to an another surface of the two buffering plates other than the opposite surfaces of the two buffering plates.

Specifically, the fireproof buffering structure comprises two buffering plates and further comprises a first auxiliary fireproof plate and a second auxiliary fireproof plate. A surface of the fireproof plate is attached to one of the two buffering plates. A surface of the first auxiliary fireproof plate is attached to an another surface of the fireproof plate. A surface of the second auxiliary fireproof plate being attached to an another surface of the first auxiliary fireproof plate, and the other one of the two buffering plates is attached to an another surface of the second auxiliary fireproof plate.

Specifically, a combustion rate of the first auxiliary fireproof plate is lower than the combustion rate of the buffering plates.

Specifically, combustion rates of the first auxiliary fireproof plate and the second auxiliary fireproof plate are lower than the combustion rate of the buffering plates.

As will be seen more clearly from the detailed description following below, the claimed supporting cushion apparatus includes a covering member and the abovementioned fireproof buffering structure accommodated inside the covering member.

Preferably, the covering member comprises a head supporting portion and two flanking portions connected with two sides of the head supporting portion, and the fireproof buffering structure is accommodated in at least one of the head supporting portion and the two flanking portions.

Specifically, a covering pocket is disposed on at least one of the head supporting portion and the two flanking portions, and the fireproof buffering structure is accommodated in the covering pocket.

Specifically, a soft filler is disposed on a surface of the fireproof buffering structure accommodated in at least one of the covering pocket and the head supporting portion and the two flanking portions.

Specifically, a side compartment is disposed outside the covering pocket in at least one of the head supporting portion and the two flanking portions, and the soft filler fills the side compartment.

As will be seen more clearly from the detailed description following below, the claimed safety seat includes a main body and the abovementioned fireproof buffering structure disposed on the main body.

Preferably, the fireproof buffering structure is attached on the main body.

Specifically, the fireproof buffering structure is attached on at least one of a seat portion and a side portion and a backrest portion of the main body.

Specifically, the fireproof plate of the fireproof buffering structure is closer to a seating space of the safety seat than the buffering plate, and the buffering plate is positioned between the fireproof plate and an inner side of the safety seat.

As will be seen more clearly from the detailed description following below, another claimed safety seat includes a main body and the abovementioned supporting cushion apparatus disposed on the main body.

In contrast to conventional buffering structures, the fireproof buffering structure of the present application includes the buffering plate and the fireproof plate combined with each other. The buffering plate has good impact absorbing capacity for providing a soft and comfortable seating environment and buffering and protection effects during a crash accident. Besides, the attached fireproof plate can reduce the combustion rate of the integral structure when catching fire. Therefore, the fireproof buffering structure, which can be disposed in the safety seats <NUM>, <NUM>, achieves the inventive purposes of safety and comfort.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to a first embodiment of the present application. The fireproof structure <NUM> provided by the present application is mainly used in a child safety seat. The fireproof buffering structure <NUM> includes a buffering plate <NUM> and a fireproof plate <NUM> attached to the buffering plate <NUM>. The buffering plate <NUM> is made of soft material and thereby has good buffering and impact absorbing capacity for protecting an infant's head from fierce impact during an accident. A combustion rate (and a flammability) of the fireproof plate <NUM> is lower than a combustion rate of the buffering plate <NUM>, so a cross-sectional combustion rate of the integrated buffering plate <NUM> and fireproof plate <NUM> is lower than a cross-sectional combustion rate of the buffering plate <NUM> alone. The buffering plate <NUM> can be a foam plate made of material such as polyurethane (PU), expanded polypropylene (EPP), expanded polystyrene (EPS) or Expandable Polyethylene (EPE). The buffering plate <NUM> of the present application can be a foam plate with a density substantially between <NUM>/m<NUM> and <NUM>/m<NUM>. Specifically, the foam plate can be made of inert foam, and the density can be substantially <NUM>/m<NUM>. Specifically, the fireproof plate <NUM> can be made of polyethylene (PE), polypropylene (PP), EPS, EPP, expanded polystyrene (EPO), fireproof foam, ethylene-vinylacetate copolymer (EVA), or botanical cotton, and the botanical cotton can be corn cotton. A thickness of the fireproof buffering structure <NUM> can be substantially smaller than <NUM>, preferably <NUM>. The buffering plate <NUM> and the fireproof plate <NUM> are attached to each other via, but not limited to, glue or twin adhesive, and a shape of the fireproof plate <NUM> can correspond to a shape of the buffering plate <NUM>.

Besides a double-layered structure of the fireproof buffering structure mentioned above, the fireproof buffering structure of the present application can also be, but is not limited to, a triple-layered structure, a quadruple-layered structure, or a quintuple-layered structure, which is described as follows.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to a second embodiment of the present application. The fireproof buffering structure <NUM> is a triple-layered structure and includes a fireproof plate <NUM> and two buffering plates <NUM>. The two buffering plates <NUM> are respectively attached to a front surface of the fireproof plate <NUM> and a rear surface of the fireproof plate <NUM>.

Based on the triple-layered structure of the second embodiment, other auxiliary layers are added to the triple-layered structure, which is described in a third and a fourth embodiments as follows.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to a third embodiment of the present application. The fireproof buffering structure <NUM> is a quadruple-layered structure and includes two buffering plates <NUM>, a fireproof plate <NUM>, and a first auxiliary fireproof plate <NUM>. A surface of the fireproof plate <NUM> is attached to one of the two buffering plates <NUM>, and a surface of the other buffering plate <NUM> is attached to another surface of the fireproof plate <NUM>. The first auxiliary fireproof plate <NUM> is attached to a surface of the other buffering plate <NUM>. Therefore, the first auxiliary fireproof plate <NUM> is attached to another surface of the other buffering plate <NUM> away from the fireproof plate <NUM>.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to a fourth embodiment of the present application. The fireproof buffering structure <NUM> is a quintuple-layered structure and includes two buffering plates <NUM>, a fireproof plate <NUM>, a first auxiliary fireproof plate <NUM>, and a second auxiliary fireproof plate <NUM>. Two surfaces of the two buffering plates <NUM> are respectively attached to a front surface of the fireproof plate <NUM> and a rear surface of the fireproof plate <NUM>. The first auxiliary fireproof plate <NUM> and the second auxiliary fireproof plate <NUM> are respectively attached to two another surfaces of the two buffering plates <NUM>. Therefore, the first auxiliary fireproof plate <NUM> and the second auxiliary fireproof plate <NUM> are respectively attached to the two another surfaces of the two buffering plates <NUM> away from the fireproof plate <NUM>.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to a fifth embodiment of the present application. The fireproof buffering structure <NUM> is a triple-layered structure and includes a buffering plate <NUM>, a fireproof plate <NUM>, and a first auxiliary fireproof plate <NUM>. The fireproof plate <NUM> and the first auxiliary fireproof plate <NUM> are respectively attached to a front surface of the buffering plate <NUM> and a rear surface of the buffering plate <NUM>.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to a sixth embodiment of the present application. Based on the triple-layered structure of the fifth embodiment, other auxiliary layers are added to the triple-layered structure in the sixth embodiment. The fireproof buffering structure <NUM> includes three buffering plates <NUM>, a fireproof plate <NUM>, and a first auxiliary fireproof plate <NUM>. A surface of the fireproof plate <NUM> and a surface of the first auxiliary fireproof plate <NUM> are respectively attached to a front surface and a rear surface of one of the three buffering plates <NUM>, and the other two of the three buffering plates <NUM> are respectively attached to another surface of the fireproof plate <NUM> and another surface of the first auxiliary fireproof plate <NUM>.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to a seventh embodiment of the present application. The fireproof buffering structure <NUM> is a triple-layered structure and includes a buffering plate <NUM>, a fireproof plate <NUM>, and a first auxiliary fireproof plate <NUM>. A surface of the fireproof plate <NUM> is attached to the buffering plate <NUM>, and the first auxiliary fireproof plate <NUM> is attached to another surface of the fireproof plate <NUM>.

Based on the triple-layered structure of the seventh embodiment, other auxiliary layers are added to the triple-layered structure, which is described in an eighth embodiment and a ninth embodiment as follows.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to an eighth embodiment of the present application. The fireproof buffering structure <NUM> includes two buffering plates <NUM>, a fireproof plate <NUM>, and a first auxiliary fireproof plate <NUM>. A surface of the fireproof plate <NUM> is attached to one of the two buffering plates <NUM>. A surface of the first auxiliary fireproof plate <NUM> is attached to another surface of the fireproof plate <NUM>, and the other buffering plate <NUM> is attached to another surface of the first auxiliary fireproof plate <NUM>.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to a ninth embodiment of the present application. The fireproof buffering structure <NUM> includes two buffering plates <NUM>, a fireproof plate <NUM>, a first auxiliary fireproof plate <NUM>, and a second auxiliary fireproof plate <NUM>. The first auxiliary fireproof plate <NUM> and the fireproof plate <NUM> are attached between opposite surfaces of the two buffering plates <NUM> facing towards each other, and the second auxiliary fireproof plate <NUM> is attached to another surface of the two buffering plates <NUM> other than the opposite surfaces of the two buffering plates <NUM>.

Please refer to <FIG> is a perspective diagram of a fireproof buffering structure <NUM> according to a tenth embodiment of the present application. The fireproof buffering structure <NUM> is a quintuple-layered structure and includes two buffering plates <NUM>, a fireproof plate <NUM>, a first auxiliary fireproof plate <NUM>, and a second auxiliary fireproof plate <NUM>. A surface of the fireproof plate <NUM> is attached to one of the two buffering plates <NUM>, a surface of the first auxiliary fireproof plate <NUM> is attached to another surface of the fireproof plate <NUM>, a surface of the second auxiliary fireproof plate <NUM> is attached to another surface of the first auxiliary fireproof plate <NUM>, and the other buffering plate <NUM> is attached to another surface of the second auxiliary fireproof plate <NUM>.

The abovementioned buffering plates of the second embodiment to the tenth embodiment can be foam plates as the foam plate of the first embodiment. The fireproof plate, the first auxiliary fireproof plate, and the second auxiliary fireproof plate can be made of PE, PP, EPS, EPP, EPO, fireproof foam, EVA, or botanical cotton. Combustion rates of the first auxiliary fireproof plate and the second auxiliary fireproof plate are lower than the combustion rate of the buffering plates. For the third embodiment to the sixth embodiment, two or all of the fireproof plate, the first auxiliary fireproof plate, and the second auxiliary fireproof plate can be made of the same material or different materials. For the seventh embodiment to the ninth embodiment, the fireproof plate and the first auxiliary fireproof plate are made of different materials. The second auxiliary fireproof plate <NUM> of the ninth embodiment can be made of the same material as one of the fireproof plate <NUM> and the first auxiliary fireproof plate <NUM> or can be made of a material different from the fireproof plate <NUM> and the first auxiliary fireproof plate <NUM>. For the tenth embodiment, the fireproof plate <NUM> and the second auxiliary fireproof plate <NUM> can be respectively made of a material different from the first auxiliary fireproof plate <NUM>, while the fireproof plate <NUM> and the second auxiliary fireproof plate <NUM> can be made of the same material or different materials. By adjusting the materials of the multiple fireproof plates, an integral combustion rate of the fireproof buffering structure can be adjusted. Besides, the fireproof plates are usually harder than the buffering plates, which can transfer an impact onto the entire buffering plates during a crash accident so that the buffering plates are deformed uniformly to achieve better buffering effect.

Please refer to <FIG> is a perspective diagram of a safety seat <NUM> with the fireproof buffering structure <NUM> of the present application. The present application further discloses the safety seat <NUM> with a fireproof buffering structure <NUM>. The fireproof buffering structure <NUM> can be disposed on or directly attached on a main body of the safety seat <NUM>. For example, the buffering structure <NUM> can be attached to a position on at least one of a seat portion <NUM>, a side portion <NUM>, a backrest portion <NUM>, and a headrest portion <NUM> of the main body. According to the position where the buffering structure <NUM> is attached, a shape of the buffering structure <NUM> can be strip-shaped, rectangular, or circular, but not limited thereto. It is noticed that the buffering structure <NUM> can be, but is not limited to, one of the buffering structures according to the first embodiment to the tenth embodiment. Besides, if an outmost layer of the fireproof buffering structure <NUM> is a fireproof plate, the fireproof plate is closer to a seating space of the safety seat <NUM> than the neighboring buffering plates or the buffering plate that the fireproof plate is attached to. That is, the buffering plates are positioned between the fireproof plate and an inner side of the safety seat <NUM> so that the fireproof plate is in contact with a child in the safety seat <NUM>.

Further detail of that the abovementioned fireproof buffering structures are configured for the first embodiment, the third embodiment, the seventh embodiment, and the ninth embodiment is described as follows. Please refer to <FIG> is a top view of the fireproof buffering structure <NUM> disposed to the headrest portion <NUM> according to the first embodiment of the present application. As shown in <FIG>, the fireproof buffering structures <NUM> are disposed on inner sides of two flanking sides of the headrest portion <NUM>. The fireproof plates <NUM> are closer to an inner space surrounded by the headrest portion <NUM> than the buffering plates <NUM>. Please refer to <FIG>. <FIG> is a top view of the fireproof buffering structure <NUM> disposed to the headrest portion <NUM> according to the third embodiment of the present application. <FIG> is a top view of the fireproof buffering structure disposed <NUM> to the headrest portion <NUM> according to the seventh embodiment of the present application. <FIG> is a top view of the fireproof buffering structure <NUM> disposed to the headrest portion <NUM> according to the ninth embodiment of the present application. As shown in <FIG>, the first auxiliary fireproof plates <NUM>, <NUM> of the fireproof buffering structures <NUM>, <NUM> respectively and the second auxiliary fireproof plates <NUM> of the fireproof buffering structures <NUM> are closer to an inner space surrounded by the headrest portion <NUM>, while the buffering plates <NUM> of the fireproof buffering structures <NUM> are between the first auxiliary fireproof plates <NUM> and the inner sides of the headrest portion <NUM>, and the buffering plates <NUM> of the fireproof buffering structures <NUM> are between the first auxiliary fireproof plates <NUM> and the inner sides of the headrest portion <NUM>, and the buffering plates <NUM> of the fireproof buffering structures <NUM> are between the second auxiliary fireproof plate <NUM> and the inner sides of the headrest portion <NUM>.

Please refer to <FIG> is a perspective diagram of the safety seat <NUM> with a supporting cushion apparatus <NUM> according to an embodiment of the present application. As shown in <FIG>, the present application further discloses that a safety seat <NUM> includes a main body <NUM> and the supporting cushion apparatus <NUM> disposed on the main body <NUM>. The supporting cushion apparatus <NUM> can be a headrest for supporting the infant's head in the safety seat <NUM>. The supporting cushion apparatus <NUM> includes the fireproof buffering structure disclosed by the present application so as to provide protection for the infant's head.

Please refer to <FIG> and <FIG>. <FIG> is a perspective diagram of the supporting cushion apparatus <NUM> according to the embodiment of the present application. <FIG> is a diagram of the fireproof buffering structure <NUM> partially accommodated in a covering pocket <NUM> according to an embodiment of the present application. The supporting apparatus <NUM> includes a covering member <NUM> and the fireproof buffering structure <NUM> accommodated inside the covering member <NUM>. The fireproof buffering structure <NUM> can be a structure of the abovementioned fifth embodiment, which includes the buffering plate <NUM>, and the fireproof plate <NUM> and the first auxiliary fireproof plate <NUM> respectively attached to a front surface of the buffering plate <NUM> and a rear surface of the buffering plate <NUM>. The covering member <NUM> includes a head supporting portion <NUM> and two flanking portions <NUM> connected with two sides of the head supporting portion <NUM>. A child in a car ride can rest his or her head on the head supporting portion <NUM>. The fireproof buffering structure <NUM> can be accommodated in each of the two flanking portions <NUM> which are located on two sides of the child's head for providing protection. Specifically, the covering pocket <NUM> with an opening can be disposed on at least one of the two flanking portions <NUM> and the head supporting portion <NUM>, and the fireproof buffering structure <NUM> can be put into the covering pocket <NUM> through the opening. A shape of the fireproof buffering structure <NUM> can correspond to shapes of the flanking portion <NUM> and the covering pocket <NUM>, and a size of the fireproof buffering structure <NUM> can be only slightly smaller than the covering pocket <NUM> so that the fireproof buffering structure <NUM> can be properly restrained in the flanking portion <NUM> after being enclosed into the covering pocket <NUM>. The fireproof buffering structure <NUM> can also be accommodated in the head supporting portion <NUM>. For example, in another embodiment of the present application, the fireproof buffering structures <NUM> are accommodated in the head supporting portion <NUM> and the flanking portions <NUM> of the covering member <NUM>. In another embodiment of the present application, the fireproof buffering structure <NUM> is accommodated only in the head supporting portion <NUM> but not in the flanking portions <NUM>, and the description of the exemplary embodiments are intended to be illustrative and not to limit the scope of the invention.

Since the fireproof plate <NUM> made of PE is harder than the buffering plate <NUM> and is disposed on a surface of the fireproof buffering structure <NUM> closer to an inner space surrounded by the covering member <NUM>, the infant with his or her head rested in the inner space and on the fireproof plate <NUM> might feel uncomfortable. Therefore, a soft filler can be disposed on the fireproof plate <NUM> accommodated in the flanking portion <NUM>. A side compartment can be disposed outside the covering pocket <NUM> accommodated in the flanking portion <NUM> or in the head supporting portion <NUM>, and the soft filler can fill the side compartment. In other embodiments, the soft filler can directly fill the covering pocket <NUM> for covering the fireproof plate <NUM> or can be disposed on the fireproof plate <NUM> accommodated in the covering pocket <NUM> or the head supporting portion <NUM>, and the description of the exemplary embodiments are not intended to limit the scope of the invention but to be illustrative about that the soft filler is required to be positioned on an outer surface of the fireproof plate <NUM>. The soft filler can be foam made of materials, such as PU, EPP, EPS, or EPE, or can be made of a material that improves comfortableness, such as cotton. It is noticed that the fireproof buffering structure accommodated in the supporting cushion apparatus <NUM> can be formed in other configurations else the fireproof buffering structures of the first embodiment to the tenth embodiment besides the abovementioned fireproof buffering structure <NUM>.

Claim 1:
A supporting cushion apparatus (<NUM>), comprising:
a fireproof buffering structure (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), the fireproof buffering structure (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising:
a buffering plate (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>); and
a fireproof plate (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) combined with the buffering plate (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), a combustion rate of the fireproof plate (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) being lower than a combustion rate of the buffering plate (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>),
and characterized by further comprising:
a covering member (<NUM>), the fireproof buffering structure (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) being accommodated inside a covering pocket (<NUM>) disposed on at least one of a head supporting portion (<NUM>) and two flanking portions (<NUM>) connected with two sides of the head supporting portion (<NUM>) of the covering member (<NUM>).