Beds – Support for users body or part thereof – Removable support specially adapted for seating
Reexamination Certificate
1998-03-10
2001-05-08
Melius, Terry Lee (Department: 3628)
Beds
Support for users body or part thereof
Removable support specially adapted for seating
C264S046600, C297S452270, C297S452610, C029S091100
Reexamination Certificate
active
06226819
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a seat used for an industrial vehicle such as a fork lift truck and a tractor, a seat used in an office or as furniture and a chair used as furniture and, in particular, relates to a seat comprising a foamed body having various hardnesses and a surface material connected in one with the foamed body and a method for manufacturing such a seat.
BACKGROUND OF ART
A method of the art for manufacturing a seat comprising a foamed body having various hardnesses and an air-permeable surface material connected in one with the foamed body is shown in FIGS.
5
and (this method is described in a Japanese patent application filed on Jul. 1, 1996,). This manufacturing method is carried out as follows.
A first foamed body
51
as a base part has been molded in advance. As shown in
FIG. 5
, firstly, a liquid foamable mixture
52
such as a polyurethane foam is introduced and layered on the first foamed body
51
. A thickness of the liquid foamable mixture
52
layered on the first foamed body
51
is generally leveled over a flat part
51
′ of the first foamed body
51
. An air-permeable surface material
54
is composed of an upper part
55
and side parts
56
,
56
′ stitched on both sides of the upper part
55
. The upper part
55
of the surface material
54
is placed on the mixture
52
layered on the first foamed body
51
, and the side parts
56
,
56
′ are positioned on both side surfaces of the first foamed body
51
.
A part of the mixture
52
which contacts with the flat part
51
′ of the first foamed body
51
is impregnated into the first foamed body
51
through the flat part
51
′ thereof, so that an impregnated layer is formed.
Then, a pressure applying die
60
is positioned above the surface material ( see
FIG.6
) . This pressure applying die
60
is hollowed, and a plurality of suction holes
61
,
62
are provided adjacent to ascending parts formed on a surface
60
′ of the die
60
. Descending parts formed on the seat are molded by those ascending parts of the die
60
. The pressure applying die
60
is moved downward and an inner space thereof is simultaneously pumped out through the suction holes
61
,
62
. Both the liquid foamable mixture
52
and the surface material
54
are pressed and compressed between the pressure applying die
60
and the first foamed body
51
when the mixture
52
has completed a gas reaction thereof but is still in a visco-elastic flowing condition.
As described above, the low air-permeable impregnated layer is formed in the foamed body
51
which contacts with the mixture
52
layered thereon, so that the whole becomes a low air-permeable composite material, and when the inner space of the pressure applying die
60
is pumped out during the pressing and compression, the pumping force acts on the low air-permeable composite material, so that a large pressure difference is produced between an inside of the composite material and a pumping side thereof. Thus, even though a molding surface of the pressure applying die has a complicated shape, the liquid foamable mixture in the visco-elastic flowing condition is attracted toward the pumping side with the surface material while a reactive force caused by the pressing and compression acts thereto, so that the surface material
54
is pushed onto the pressure applying die so as to follow the molding surface
60
′ of the pressure applying die
60
. A portion which can be molded and shaped in a desired shape corresponding to a shape of a die by sucking the liquid foamable mixture with the surface material as described above is hereinafter referred to as a sucked and molded portion.
Then, the liquid foamable mixture
52
is changed (or cured) into a solid condition ( a resin like condition ) , so that the second foamed body
51
having a desired resiliency can be formed, and simultaneously, a back surface of the surface material
54
is connected in one with an upper side of the second foamed body
51
and the first foamed body is connected in one with a lower side thereof.
If a hardness of the first foamed body and that of the second foamed body are adjusted, respectively, or if the compressibility and the like of the second foamed body is adjusted when carrying out the pressing and compression, then a seat having various hardnesses provided in the surface material can be manufactured.
As described above, according to this method of the art, a seat with an air-permeable surface material can be manufactured without use of a lower die, such that the first foamed body is connected in one with the second foamed body and even though a molding surface of a pressure applying die has a complicated shape, the surface material can be connected with the second foamed body and can have a shape corresponding to the molding surface of the pressure applying die.
However, since the liquid foamable mixture in a visco-elastic flowing condition is introduced and layered thereon in level, the mixture is uniformly resinified (cured) , so that the layered mixture can be easily compressed uniformly, and, as described above, since the impregnated layer is formed, the whole of the mixture
52
and the first foamed body
51
results in a low air-permeable composite material, so that the whole of the first foamed body
51
is pushed toward the pressure applying die
60
by the pressure difference produced by the suction. That is, as indicated by a broken line shown in
FIG. 6
, the first foamed body
51
is lifted upward and moved toward the mixture
52
so as to crush the whole of the mixture
52
and so as to thin the thickness thereof, and then, when the mixture is cured, it may make the tactile feeling of a seat surface worse.
If the sucking force is reduced to avoid such a lift, a molding of the mixture by the suction can not be carried out sufficiently.
Also, when manufacturing a seat having a complicated shape and deeper descending parts, that is, when manufacturing such a seat by use of a pressure applying die having a complicated molding surface shape, it is required to suck strongly to carry out sufficient molding by the suction. However, the first foamed body
51
is lifted more strongly upward and moved toward the mixture
52
, and as a result, the mixture
52
is crushed more.
Moreover, if the mixture is cured when the first foamed body is lifted upward, the first foamed body is recovered to its original shape by a resiliency of the first foamed body after completing the molding, and as a result, a part of the second foamed body desired to be flat is deeply depressed, and thus, a seat having a desired shape can not be manufactured.
As described above, when molding a seat shape, the mixture
52
should not be compressed by the lift of the first foamed body. (The mixture at such a portion is hereinafter referred to as a portion not to be compressed.)
The present invention is made in order to solve those problems, and an object thereof is to provide a seat and a method for manufacturing the seat wherein the seat has a surface shape corresponding to a molding surface of a molding die, a surface material of the seat is connected in one with a foamed body thereof and a tactile feeling of a surface of the seat is improved.
Another object of the present invention is to provide the seat and a method for manufacturing the seat wherein an air-permeable surface material can we used for the seat described above.
Still another object of the present invention is to provide the seat and a method for manufacturing the seat wherein an upper layer of the seat which contacts a person is soft and a lower layer thereof which supports a weight of the person is hard.
Yet still another object of the present invention is to provide the seat and a method for manufacturing the seat wherein the hardness of the upper layer is partially different.
DISCLOSURE OF INVENTION
A seat according to the present invention, which achieves those objects, comprises an air-permeable surface material and a foamed body covered with the surface material. The foamed b
Ogawa Taro
Senoo Yasumasa
Toda Yasuyuki
Watadani Takeshi
Hewitt James M.
Melius Terry Lee
Namba Press Works., Ltd.
Renner, Kenner, Greive, Bobak, Taylor and Weber
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