U.S. patent application number 11/594858 was filed with the patent office on 2007-05-17 for structure for attaching spring.
This patent application is currently assigned to KOKUYO FURNITURE CO., LTD.. Invention is credited to Toshiyuki Horiki, Nobuyuki Ueda.
Application Number | 20070108820 11/594858 |
Document ID | / |
Family ID | 43480834 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070108820 |
Kind Code |
A1 |
Ueda; Nobuyuki ; et
al. |
May 17, 2007 |
Structure for attaching spring
Abstract
In order to adjust a reaction force of a frame-like spring, the
invention provides an attachment structure of a reaction force
frame element, which is frame-like spring, having an upper end,
which is one end, connected to an upper frame element, which is
first attaching object, and a lower end, which is the other end,
connected to a lower frame element, which is second attaching
object, wherein the upper end is attached to the upper frame
element through an upper attaching portion, which is first
attaching portion, and the lower end is attached to the lower frame
element through a lower attaching portion, which is second
attaching portion, and, the lower attaching portion is configured
to change a relative angle formed by the reaction force frame
element and a downward face, which is attaching face, of the lower
frame element.
Inventors: |
Ueda; Nobuyuki; (Osaka-shi,
JP) ; Horiki; Toshiyuki; (Nagano, JP) |
Correspondence
Address: |
WESTERMAN, HATTORI, DANIELS & ADRIAN, LLP
1250 CONNECTICUT AVENUE, NW
SUITE 700
WASHINGTON
DC
20036
US
|
Assignee: |
KOKUYO FURNITURE CO., LTD.
Osaka-shi
JP
Takano Co., Ltd.
Nagano
JP
|
Family ID: |
43480834 |
Appl. No.: |
11/594858 |
Filed: |
November 9, 2006 |
Current U.S.
Class: |
297/300.5 |
Current CPC
Class: |
A47C 7/445 20130101;
F16F 1/22 20130101; A47C 7/4454 20180801 |
Class at
Publication: |
297/300.5 |
International
Class: |
A47C 3/00 20060101
A47C003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 11, 2005 |
JP |
2005-328180 |
Claims
1. A structure for attaching spring having one end connected to a
first attaching object and other end connected to a second
attaching object, respectively, and being arranged to these
attaching objects in parallel, wherein one end is attached to the
first attaching object via a first attaching portion and other end
is attached to the second attaching object via a second attaching
portion; and at least one of the first attaching portion and the
second attaching portion is formed so as to be able to change a
relative angle between the spring and the attaching faces of the
first attaching object or the second attaching object.
2. The structure for attaching spring according to claim 1, wherein
the first attaching portion comprises a shaft member for pivotally
fitting the spring to the first attaching object, and an adjusting
member, which is disposed at a position displaced into the opposite
side of the side directed from the shaft member to the second
attaching object, for pressing the first attaching object or the
spring.
3. The structure for attaching spring according to claim 1, wherein
the second attaching portion comprises a shaft member for pivotally
fitting the spring to the second attaching object, and an adjusting
member, which is disposed at a position displaced into the opposite
side of the side directed from the shaft member to the first
attaching object, for pressing the second attaching object or the
spring.
4. The structure for attaching spring according to claim 2, wherein
the adjusting member is a male screw member, and an abutting
position with the first attaching object, the second attaching
object, or the spring is changed by screwing this male screw member
backward and forward with respect to a female screw portion which
is disposed penetrating through the first attaching object or the
second attaching object.
5. The structure for attaching spring according to claim 1, wherein
the first attaching object is an upper frame element to form an
upper portion of a backrest of a chair, and the second attaching
object is a lower frame element to form a lower portion of the
backrest of the chair.
6. The structure for attaching spring according to claim 1, wherein
the first attaching object is a back frame to form at least one
portion of a backrest of a chair, and the second attaching object
is a base to support a seat of the chair and the backrest
thereof.
7. The structure for attaching spring according to claim 1, wherein
the springs are arranged separated at a rear face of a backrest of
a chair, and the spring has the same shape as a back frame, an
upper frame element, or a lower frame element.
8. The structure for attaching spring according to claim 3, wherein
the adjusting member is a male screw member, and an abutting
position with the first attaching object, the second attaching
object, or the spring is changed by screwing this male screw member
backward and forward with respect to a female screw portion which
is disposed penetrating through the first attaching object or the
second attaching object.
9. The structure for attaching spring according to claim 2, wherein
the first attaching object is an upper frame element to form an
upper portion of a backrest of a chair, and the second attaching
object is a lower frame element to form a lower portion of the
backrest of the chair.
10. The structure for attaching spring according to claim 3,
wherein the first attaching object is an upper frame element to
form an upper portion of a backrest of a chair, and the second
attaching object is a lower frame element to form a lower portion
of the backrest of the chair.
11. The structure for attaching spring according to claim 4,
wherein the first attaching object is an upper frame element to
form an upper portion of a backrest of a chair, and the second
attaching object is a lower frame element to form a lower portion
of the backrest of the chair.
12. The structure for attaching spring according to claim 2,
wherein the first attaching object is a back frame to form at least
one portion of a backrest of a chair, and the second attaching
object is a base to support a seat of the chair and the backrest
thereof.
13. The structure for attaching spring according to claim 3,
wherein the first attaching object is a back frame to form at least
one portion of a backrest of a chair, and the second attaching
object is a base to support a seat of the chair and the backrest
thereof.
14. The structure for attaching spring according to claim 4,
wherein the first attaching object is a back frame to form at least
one portion of a backrest of a chair, and the second attaching
object is a base to support a seat of the chair and the backrest
thereof.
15. The structure for attaching spring according to claim 2,
wherein the springs are arranged separated at a rear face of a
backrest of a chair, and the spring has the same shape as a back
frame, an upper frame element, or a lower frame element.
16. The structure for attaching spring according to claim 3,
wherein the springs are arranged separated at a rear face of a
backrest of a chair, and the spring has the same shape as a back
frame, an upper frame element, or a lower frame element.
17. The structure for attaching spring according to claim 4,
wherein the springs are arranged separated at a rear face of a
backrest of a chair, and the spring has the same shape as a back
frame, an upper frame element, or a lower frame element.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a structure for attaching a
spring which is entirely formed in a frame, having one end
connected to a first attaching object and other end connected to a
second attaching object, respectively.
[0003] 2. Description of the Related Art
[0004] Conventionally, as a method to attach a spring which can
accumulate reaction forces due to an elastic deformation so as to
be able to adjust the reaction force, for example, an aspect of
fixing one end of a compression coil spring and attaching other end
of the compression coil spring in a longitudinal direction movably
is considered (for example, please refer to a Japanese Patent
Application Laid-Open No. 2003-265256 (particularly, refer to FIG.
11)).
[0005] Thus, there are various springs other than the compression
coil spring and among them, there is a spring, which is formed in
an elongated shape extending in a direction, is curved in a
direction vertical to the longitudinal direction, and can
accumulate the reaction forces. An object of the present invention
is to provide means for adjusting the reaction force in such a
spring.
SUMMARY OF THE INVENTION
[0006] Namely, a structure for attaching spring according to the
present invention is an attaching structure of spring having one
end connected to a first attaching object and other end connected
to a second attaching object, respectively, and being arranged to
these attaching objects in parallel, wherein the one end is
attached to the first attaching object via a first attaching
portion and the other end is attached to the second attaching
object via a second attaching portion; and at least one of the
first attaching portion and the second attaching portion is formed
so as to be able to change a relative angle between the spring and
the attaching faces of the first attaching object or the second
attaching object.
[0007] According to such a structure, when the elastic force acting
from the spring on the attaching object is made smaller, for
example, due to an aging phenomena of the spring, by changing the
relative angle into the side where the reaction forces accumulated
in the spring is made larger to keep the elastic force or by
changing the relative angle when a user feels that the elastic
force received by the backrest from the spring is too strong or too
weak, it is possible to adjust the reaction forces accumulated in
the spring, namely, the elastic force acting on the backrest.
[0008] As an aspect capable of specifically realizing such a
structure, the constitution that the second attaching portion
comprises a shaft member for pivotally fitting the spring to the
second attaching object, and an adjusting member, which is disposed
at a position displaced into the opposite side of the side directed
from the shaft member to the first attaching object, for pressing
the second attaching object or the spring may be available.
[0009] As a constitution capable of easily realizing the
constitution described in the former clause, the constitution that
the adjusting member is a male screw member, and an abutting
position with the first attaching object, the second attaching
object, or the spring is changed by screwing this male screw member
backward and forward with respect to a female screw portion which
is disposed penetrating through the first attaching object or the
second attaching object may be considered. Employing such a
constitution, since a head portion of the male screw which is the
adjusting member is exposed on the surface of the opposite side of
the second attaching object, it is possible to adjust the abutting
position between the adjusting member and the second attaching
object very easily.
[0010] As a constitution capable of easily obtaining the advantages
as described above, the constitution that the first attaching
object is an upper frame element to form an upper portion of a
backrest of a chair, and the second attaching object is a lower
frame element to form a lower portion of the backrest of the chair
may be considered. According to such a constitution, it is possible
to incline the upper frame element with respect to the lower frame
element and acting the reaction force on the upper frame element in
association with tilt, and further, the reaction force given by the
frame-like spring can be adjusted.
[0011] As other constitution preferably capable of obtaining the
above-described advantages, the constitution that the first
attaching object is a base to support a seat of a chair and a
backrest thereof, and the second attaching object is a back frame
to form at least one portion of the backrest of the chair may be
considered. According to such a constitution, acting the reaction
force on the back frame in accordance with the rocking operation of
the backrest, the rocking reaction force given by the frame-like
spring can be further adjusted.
[0012] In addition, according to a constitution that the springs
are arranged separated at a rear face of a backrest of a chair, and
the spring has the same shape as a back frame, an upper frame
element, or a lower frame element, it is possible to obtain the
appearance such that the spring seems a portion of the backrest,
and the appearance of the chair using such a spring can be
arranged.
[0013] Employing the attaching structure of the spring according to
the present invention, when the elastic force acting from the
spring on the attaching object is made smaller, for example, due to
the aging phenomena of the spring, by changing the relative angle
into the side where the reaction forces accumulated in the spring
is made larger to keep the elastic force or by changing the
relative angle when a user feels that the elastic force received by
the back from the spring is too strong or too weak, it is possible
to adjust the reaction forces accumulated in the spring, namely,
the elastic force acting on the backrest.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view showing a chair of an
embodiment according to the present invention as seen from the
front side thereof;
[0015] FIG. 2 is a perspective view showing the chair according to
the embodiment as seen from the back side thereof;
[0016] FIG. 3 is a side view of the chair according to the
embodiment;
[0017] FIG. 4 is a rear view of the chair according to the
embodiment;
[0018] FIG. 5 is a plan view of the chair according to the
embodiment;
[0019] FIG. 6 is a side view showing the synchronous rocking
operation of the chair according to the embodiment;
[0020] FIG. 7 is a side view showing the state that an upper frame
element on the chair according to the embodiment is displaced
backward;
[0021] FIG. 8 is a perspective view showing the deformation
operation of a backrest face of the chair according to the
embodiment;
[0022] FIG. 9 is a plan view showing the deformation operation of a
backrest face of the chair according to the embodiment;
[0023] FIG. 10 is a side view enlarging the substantial portions of
the chair according to the embodiment;
[0024] FIG. 11 is an exploded perspective view of the substantial
portions of the chair according to the embodiment;
[0025] FIG. 12 is a side view enlarging the substantial portions of
the chair according to other embodiment of the present
invention;
[0026] FIG. 13 is a side view of the chair according to other
embodiment of the present invention;
[0027] FIG. 14 is a side view enlarging the substantial portions of
the chair according to other embodiment of the present invention;
and
[0028] FIG. 15 is a side view of the chair according to other
embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] An embodiment of the present invention will be described
below with reference to the drawings.
[0030] As shown in FIGS. 1 to 5, the chair according to the present
embodiment is provided with a leg 4, a base 2 supported by the leg
4, a seat 3 arranged on the base 2, and a backrest 1 pivotally
fitted on the base 2 via a horizontal support shaft 16, and this
chair can carry out the synchronous rocking operation that the seat
3 and the backrest 1 are inclined in conjunction with each
other.
[0031] Describing in detail, leg 4 is provided with a leg wing 41
mounting a plurality of casters thereon and a leg support pillar 42
rising approximately vertically from the center of the leg wing 41
so as to be able to move up and down the leg support pillar 42 due
to expansion and contraction of a gas spring (not illustrated)
installed between the leg wing 41 and the leg support pillar
42.
[0032] The base 2 is fixed to the upper end of the leg support
pillar 42, and it is possible to adjust the height positions of the
seat 3 and the backrest 1 through the moving up and down operation
of the leg support pillar 42. The base 2 incorporates an elastic
urging mechanism (not illustrated) to urge the backrest 1 turning
around the horizontal support shaft 16 forward and a fixing
mechanism (not illustrated) to fix the rocking angle of the
backrest 1 or the like. The elastic urging mechanism may
elastically urge a back frame 11 by mounting a coil spring and a
gas spring. It is assumed that the fixing mechanism may fix a
rocking angle, for example, by selectively engaging a nail to any
of plural steps of recesses disposed to the side of the back frame
11; however, in the case of using the gas spring in a push lock
system for the elastic urging mechanism, an aspect to prohibit the
expansion and contraction operation of the gas spring by driving a
bulb of the gas spring may be possible.
[0033] The seat 3 is configured so as to hold a cushion body 32
constituting a seat face on a seat receiver 31. The cushion body 32
is made as a double layered structure superimposing a urethane
cushion material on a double raschel mesh, for example, made of a
synthetic fiber, the mesh at the lower layer secures an appropriate
elasticity while absorbing the shock, and the urethane cushion
material of the upper layer keeps a stability of a posture. The
front end of the seat 3 is supported by the base 2 so as to
slidably move in a back and front direction for the base 2, and the
rear end of the seat 3 is attached to the lower frame portion 13 of
the back frame 11 via a hinge (not illustrated).
[0034] The backrest 1 is made by attaching an upholstery member 12
configuring the backrest face S on the front face of the back frame
11. The back frame 11 is provided with the lower frame portion 13
which is turnably connected around the horizontal support shaft 16
with respect to the base 2, the upper frame portion 14 which is
connected to the upper end of the lower frame portion 13 via the
hinge 17, and the reaction force frame portion 15 which is a spring
member formed in a frame shape to support this upper frame portion
14 from behind.
[0035] The lower frame portion 13 is made by mutually connecting
the right and left upper elements 131a and 131b separately arranged
in a width direction by a rigid lateral bridging material 132. The
lower frame elements 131a, 131b, and the rigid lateral bridging
material 132 are rigid bodies, for example, made of a metal. The
lower frame elements 131a and 131b are elongated from the front end
where the horizontal support shaft 16 is located to the rear
portion and curved upward at the rear end to be made into
approximately an L-shape as seen from the side.
[0036] The upper frame portion 14 is made by mutually connecting
the right and left upper frame elements 141a and 141b separately
arranged in a width direction by an elastic lateral bridging
material 142. The upper frame elements 141a and 141b are rigid
bodies, for example, made of a metal; however, the elastic lateral
bridging material 142 is an elastic body, for example, made of a
resin. The upper frame elements 141a and 141b are slowly curved
from the lower end where the hinge 17 is located and is elongated
upward while getting dented backward in some degree so as to be
made into an arch swelled forward again in the vicinity of its
upper end as seen from the side.
[0037] The reaction force frame portion 15 is made of reaction
force frame elements 151a and 151b which are frame-like springs of
the same number to support each of the upper frame elements 141a
and 141b.
[0038] Thus, according to the present invention, the reaction force
frame elements 151a and 151b have their one ends and other ends
connected to the lower frame elements 131a and 131b which are the
first members, and the upper frame elements 141a and 141b which are
the second members, respectively. The reaction force frame elements
151a and 151b can accumulate the reaction forces due to the elastic
deformation, and these reaction force frame elements 151a and 151b
are formed in a frame shape which is elongated along the upper
frame elements 141a and 141b and the lower frame elements 131a and
131b.
[0039] Specifically, lower ends 152a and 152b, which are one ends
of the reaction force frame elements 151a and 151b, are linked with
the downward faces of the lower attaching portions 133a and 133b,
respectively; and upper ends 153a and 153b are linked with the rear
faces of the upper frame elements 141a and 141b, respectively.
However, other ends of the reaction force frame elements 151a and
151b are not prevented from being fixed on the seat 3 and the base
2 supporting the backrest 1. It is assumed that the reaction force
frame elements 151a and 151b are made of an elastic body made of a
resin of the same quality, for example, as the elastic lateral
bridging material 132. According to the present embodiment, the
reaction force frame elements 151a and 151b are frame-like springs
made of a resin, which are elongated along the lower frame elements
131a and 131b and the upper frame elements 141a and 141b so as to
be made into approximately a L-shape as seen from the side. These
reaction force frame elements 151a and 151b are molded in such a
manner that the width measurements are the same or slightly smaller
than those of the frame elements 131a, 131b, 141a, and 141b and the
back and forth or the upper and lower thicknesses thereof are
thinner than those of the frame elements 131a, 131b, 141a, and 141b
(in addition, they are becoming gradually thinner as being far from
the end to be connected to the frame elements 131a, 131b, 141a, and
141b). Thereby, the appearance such that the reaction force frame
elements 151a and 151b seem a portion of the back frame 11 branched
from the frame elements 131a, 131b, 141a, and 141b is formed.
[0040] In the periphery of the hinge 17 to pivotally fit the lower
frame elements 131a and 131b and the upper frame elements 141a and
141b with each other, specifically, from the rear ends of the lower
frame elements 131a and 131b to the vicinity of the upper ends
thereof and in the range in the vicinity of the lower ends of the
upper frame elements 141a and 141b, a curved shape that the front
face of the frame is swelled forward as seen from the side is
formed. As described above, also in the vicinity of the upper ends
of the upper frame elements 141a and 141b, a curved shape that the
front face of the frame is swelled forward as seen from the side is
formed. Thus, the upholstery member 12 is tensed so as to be
bridged to the above-described region formed in the curved shape of
the lower frame elements 131a and 131b and the upper frame elements
141a and 141b.
[0041] The upholstery member 12 is mainly made by a stretch
upholstery fabric. The upholstery fabric is made by weaving an
elastic thread such as an elastomer thread or the like in a double
raschel mesh, for example, of a synthetic resin and this upholstery
fabric has both of strength and a cushion capability. The
upholstery fabric has different appearances (color, pattern, and
brilliance or the like). The upper side and right and left sides of
the upholstery fabric are kept by a backup material (not
illustrated) formed in a three-way frame or a four-way frame as
seen from the front. The backup material is a thin plate made of,
for example, a resin, and particularly, this backup material
prevents the right and left sides of the upholstery fabric from
being flexed inside to keep the upholstery fabric into the tensed
state. The upper end of the upholstery member 12 is installed in
the right and left upper frame elements 141a and 141b to be
supported, and the lower ends are installed in the right and left
lower frame elements 131a and 131b to be supported. In this case,
the backup material practices the action of a plate spring and
presses the upholstery fabric to be evaginated.
[0042] Further, it is also possible to bridge a lumber support belt
18 at the height position corresponding to the waist portion of a
person who is seated on the chair at the back of the upholstery
member 12. Even when the person who is seated on the chair leans
against the backrest face S, the region where the lumber support
belt 18 is bridged does not sink backward more than a depth
corresponding to the length of the lumber support belt 18.
[0043] The chair according to the present embodiment can perform
the synchronous rocking operation that the seat 3 and the backrest
1 are inclined in conjunction with each other. As shown in FIG. 6,
according to the synchronous rocking operation, the backrest 1 is
inclined backward and forward by entirely turning the back frame 11
around the horizontal support shaft 16. At the same time, the rear
end of the seat 3 is swung upward and downward in conjunction with
the back frame 11 and the front end of the seat 3 is slid backward
and forward.
[0044] On that basis, in the chair according to the present
embodiment, the operation is possible to displace only the left
half of the upper portion of the backrest face S backward or only
the right half thereof backward following the movement that the
person who is seated on the chair turns his or her head to look
back in the seat, extends his or her arm, and twists his or her
body. In the upper frame portion 14 supporting the upper portion of
the backrest face S moves backward and forward, the upper frame
elements 141a and 141b move independently each other, which are
paired in right and left. In other words, the upper frame element
141a at the left side is connected to the lower frame element 131a
at the left side via the hinge 17, and the upper frame element 141b
at the right side is connected to the lower frame element 131b at
the right side via the hinge 17. These upper frame elements 141a
and 141b can turn individually.
[0045] As shown in FIG. 7, when the upper frame elements 141a and
141b are inclined backward around the hinge 17, the area where the
upholstery member 12 contacts the region formed in the curved
shapes of the lower frame elements 131a and 131b and the upper
frame elements 141a and 141b gradually increased, and further, the
upholstery fabric extends upward and downward while increasing a
tension. In addition, the reaction force frame elements 151a and
151b are deformed to extend angles and accumulate the reaction
forces therein. Then, the reaction force frame elements 151a and
151b elastically urge the upper elements 141a and 141b to the
original positions, namely, forward.
[0046] Then, if any one of the upper frame elements 141a and 141b
relatively displaced in a back and front direction for other one of
the upper frame elements 141a and 141b, as shown in FIG. 8 and FIG.
9, it is possible to change the shape of the backrest face S
three-dimensionally. In this operation, the lower frame portion 13
is not necessarily driven. In addition, since the lower frame
elements 131a and 131b to be paired left and right are rigidly
connected via the rigid lateral bridging material 132, these lower
frame elements 131a and 131b constantly make a movement in a
unified manner. Therefore, the lower portion of the backrest face
S, namely, the portion backward from the waist portion of the
person who is seated on the chair constantly keeps a predetermined
shape.
[0047] If one of the upper frame elements 141a and 141b relatively
moves backward and forward to other one of them in accordance with
the movement of the person who is seated on the chair, a distance
between right and left upper frame elements 141a and 141b
increased. In this case, in order to correspond to increase of the
distance between these frame elements 141a and 141b, the elastic
lateral bridging material 142 is elastically deformed. The elastic
lateral bridging material 142 of the present embodiment connects
the upper ends of the frame elements 141a and 141b with each other
to be assembled to make the curved shape getting dented backward as
seen from the flat face. The back and front thickness of the
elastic lateral bridging material 142 is gradually thinner toward
the center in the width direction thereof from the opposite ends
thereof connected to the upper frame elements 141a and 141b, so
that the center portion is comparatively deformable than the
opposite ends. This structure serves to prevent the load from
getting centered on the place where the upper frame elements 141a
and 141b are connected to the elastic lateral bridging material
142. When one of the upper frame elements 141a and 141b relatively
moved backward and forward against other one of them, the elastic
lateral bridging material 142 is deformed so as to decrease a
curvature factor and extends the distance between the opposite
ends.
[0048] In addition, the load of the person who is seated on the
chair given to the backrest S may act on the upper frame elements
141a and 141b via the upholstery member 12 and may give the load on
the hinge 17 so as to incline the upper frame elements 141a and
141b inward. In order to reduce such a load, the elastic lateral
bridging material 142 is assembled so that it exercises the initial
elasticity so as to separate the upper frame elements 141a and 141b
in a width direction.
[0049] It is also possible to incline both of the upper frame
elements 141a and 141b via the upholstery member 12. In this case,
for example, stretch to largely through his or her back becomes
possible.
[0050] Thus, the present embodiment may provide a structure for
attaching spring having one end connected to a first attaching
object and other end connected to a second attaching object,
respectively, and arranged these attaching objects in parallel,
wherein one end is attached to the first attaching object via a
first attaching portion and other end is attached to the second
attaching object via a second attaching portion; and at least one
of the first attaching portion and the second attaching portion is
formed so as to be able to change a relative angle between the
spring and the attaching faces of the first attaching object or the
second attaching object.
[0051] Specifically, as shown in FIGS. 1 to 9, and as shown in FIG.
10 which is a side view enlarging the substantial portions and FIG.
11 which is the exploded perspective view of the substantial
portions, respectively, the first attaching objects are the upper
frame elements 141a and 141b, the second attaching objects are the
lower frame elements 131a and 131b, and the springs are the
reaction force frame elements 151a and 151b. In addition, the first
attaching portions are the upper attaching portions 143a and 143b,
and the second attaching portions are the lower attaching portions
133a and 133b, respectively. Then, these lower attaching portions
133a and 133b are provided with shaft members 1331a and 1331b for
pivotally fitting the reaction force frame elements 151a and 151b
and the lower frame elements 131a and 131b, and adjusting members
1332a and 1332b disposed at a position displaced into the opposite
side of the side directed from the shaft members 1331a and 1331b to
the upper frame elements 141a and 141b for pressing the reaction
force frame elements 151a and 151b. In addition, the adjusting
members 1332a and 1332b are male screw members according to the
present embodiment, and by screwing backward and forward these
adjusting members 1332a and 1332b with respect to female screw
portions 131ay and 131by formed protruding through the lower frame
elements 131a and 131b, the abutting positions with the reaction
force frame elements 151a and 151b are changed. Further, the
reaction force frame elements 151a and 151b are formed in the
shapes similar to those of the upper frame elements 141a and 141b
and the lower frame elements 131a and 131b to be arranged at the
rear face side of the backrest 1, for more detail, they are
arranged separated into the rear face sides of the upper elements
141a and 141b and the rear face sides of the lower frame elements
131a and 131b.
[0052] More specifically, the lower ends 152a and 152b of the
reaction force frame elements 151a and 151b are provided with
projections 154a and 154b projecting toward the lower frame
elements 131a and 131b. On the other hand, on the attaching faces
of the lower frame elements 131a and 131b, namely, on the downward
faces 131a1 and 131b1 , attaching concave portions 131ax and 13bx
capable of accommodating these projections 154a and 154b,
respectively, are provided. Further, by inserting these shaft
members 1331a and 1331b in shaft inserting holes 131az and 131bz
formed on these lower frame elements and shaft inserting holes
154ax and 154bx formed on the reaction force frame elements with
the these projections 154a and 154b accommodated in these attaching
concave portions 131ax and 131bx, the reaction force frame elements
151a and 151b are pivotally fitted to the lower frame elements 131a
and 131b, respectively.
[0053] On the other hand, the female screw portions 131ay and 131by
are disposed at the opposite side of the upper frame elements 141a
and 141b from the attaching concave portions 131ax and 131bx,
namely, the position which is displaced to the lower front
side.
[0054] In other words, in the chair C according to the present
embodiment, if the adjusting members 1332a and 1332b are moved
downward with respect to the female screw portions 131ay and 131by,
the lower ends of these adjusting members 1332a and 1332b may press
the lower ends of the reaction frame elements 151a and 151b. Then,
the lower ends 152a and 152b of the reaction force frame elements
151a and 151b may turn around the shaft members 1331a and 1331b,
and a relative angle between the reaction force frame elements 151a
and 151b and the downward faces 131a1 and 131b1 of the lower frame
elements 131a and 131b is changed. On the other hand, if the
adjusting members 1332a and 1332b are moved upward, the reaction
force frame elements 151a and 151b are elastically deformed, and
the lower ends of the reaction force frame elements 151a and 151b
move upward while keeping the state that they abut against the
adjusting members 1332a and 1332b. Also in this case, the lower
ends of the reaction force frame elements 151a and 151b may turn
around the shaft members 1331a and 1331b, so that the relative
angle between these reaction force frame elements 151a and 151b and
the downward faces 131a1 and 131b1 of the lower frame elements 131a
and 131b is changed. Accordingly, if these adjusting members 1332a
and 1332b are screwed backward and forward with respect to the
female screw portions 131ay and 131by formed on the lower frame
element 131a and 131b penetrating therethrough, the postures of the
reaction force frame elements 151a and 151b are changed, and this
makes it possible to change the reaction forces to be accumulated
in these reaction force frame elements 151a and 151b.
[0055] As described above, according to the present embodiment, it
is possible to realize the following effect since the lower
attaching portions 133a and 133b as the second attaching portion
are configured so as to be capable of changing the relative angle
between the reaction force frame elements 151a and 151b as the
spring and the downward faces 131a1 and 131b1 as the attaching
faces of the lower frame elements 131a and 131b as the second
attaching object. In other words, when the elastic force acting on
the upper frame elements 141a and 141b is made smaller due to an
aging phenomena of the reaction force frame elements 151a and 151b,
by changing the relative angle between these reaction force frame
elements 151a and 151b and the downward faces 131a1 and 131b1 into
the side where the reaction forces accumulated in the reaction
force frame elements 151a and 151b are made larger to keep the
elastic force or by changing the relative angle when a user feels
that the elastic force received by the backrest 1 from the reaction
force frame elements 151a and 151b is too strong or too weak, it is
possible to adjust the reaction forces accumulated in the reaction
force frame elements 151a and 151b, namely, the elastic force
acting on the backrest 1.
[0056] In addition, since the present embodiment employs the
constitution such that the lower attaching portions 133a and 133b
are provided with the shaft members 1331a and 1331b for pivotally
fitting the reaction force frame elements 151a and 151b to the
lower frame elements 131a and 131b and the adjusting members 1332a
and 1332b provided at a position displaced into the opposite side
from the side directed from the shaft members 1331a and 1331b
toward the upper elements 141a and 141b for pressing the lower
frame elements 131a and 131b, such a reaction adjusting mechanism
can be realized with a simple structure.
[0057] Further, since the adjusting members 1332a and 1332b are
male screw members, and these adjusting members 1332a and 1332b are
screwed backward and forward with respect to the female screw
portions 131ay and 131by formed on the lower frame element 131a and
131b penetrating therethrough so as to change the abutting position
with the lower frame elements 131a and 131b, it is possible to
easily realize the constitution described in the former clause.
Further, the headportions of the male screw members as the
adjusting members 1332a and 1332b are exposed to the surfaces at
the opposite sides of the lower frame elements 131a and 131b,
namely, on the upward face, and this makes it possible to adjust
the abutting position between the adjusting members 1332a and 1332b
and the lower frame elements 131a and 131b very easily.
[0058] Then, the reaction force frame elements 151a and 151b are
arranged to be separated on the rear face of the backrest 1, and
the reaction force frame elements 151a and 151b have the same
shapes as those of the upper frame elements 141a and 141b, and the
lower frame elements 131a and 131b, so that the appearance such
that the reaction force frame elements 151a and 151b seem a portion
of the backrest 1 can be formed so as to straighten the appearance
of the chair C.
[0059] In addition, the present invention is not limited to the
embodiments described above in detail.
[0060] For example, as shown in FIG. 12 which is a side view
enlarging the substantial portions, according to the
above-described embodiments, the female screw holes 151ax and 151bx
are disposed penetrating through the reaction frame elements 151a
and 151b, and an aspect so as to abut the head portions of the
adjusting members 1332a and 1332b as the male screw members against
the lower face of these reaction frame elements 151a and 151b is
also possible. According to this aspect, by elastically deforming
the reaction force frame elements 151a and 151b while screwing the
adjusting members 1332a and 1332b backward and forward with respect
to these female screw holes 151ax and 151bx and maintaining the
state of abutting the head portions of the adjusting members 1332a
and 1332b against the lower faces of these reaction force frame
elements 151a and 151b, the relative angle between the reaction
force frame elements 151a and 151b and the downward faces 131a1 and
131b1 as the attaching faces of the lower frame element 131a and
131b is changed.
[0061] Further, as shown in FIG. 13 which is a side view, upper
ends A152a and A 152b as one ends of reaction force frame elements
A151a and A151b formed in a frame shape and the lower ends as other
ends are connected to the upper frame elements 141a and 141b as the
first members and the base 2 as the second member, respectively,
and as shown in FIG. 14, lower attaching portions 21a and 21b as
the second attaching portions for connecting these reaction force
frame elements A151a and A151b, and the base 2 may be configured in
the same way as the second attaching portion in the above-described
embodiment. In other words, pivotally fitting the lower ends of the
reaction force frame elements A151a and A151b and the base 2 are
via shaft members 211a and 211b and providing an adjusting member
212b at a region displaced from these shaft members 211a and 211b
into the opposite sides of the upper frame elements 141a and 141b,
the relative angle between the reaction force frame elements 151a
and 151b and the downward face 2a as the attaching face of the base
2 may be changed.
[0062] In addition, as shown in FIG. 15 which is a side view, the
attaching position of the reaction force frame elements 151a and
151b as the spring for the lower frame elements 131a and 131b as
the second members is configured so as to be capable of being
changed between the position, for example, represented by a solid
line in FIG. 15 and the position, for example, represented by an
imaginary line, and the attaching position of the reaction force
frame elements 151a and 151b for the upper frame elements 141a and
141b as the first member is set at only one place. By changing the
attaching position for the lower frame elements 131a and 131b, the
reaction force frame elements 151a and 151b are elastically
deformed, and the relative angle between these reaction force frame
elements 151a and 151b at the rising position and the downward
faces 131a1 and 131b1 as the attaching faces of the lower frame
elements 131a and 131b is changed so as to enable to change the
reaction force given by these reaction force frame elements 151a
and 151b. Such an aspect may be also possible.
[0063] Even if these aspects are employed, since the relative angle
between the reaction frame element as the spring and the attaching
face can be changed, the advantages according to the
above-described embodiments can be completely obtained.
[0064] Then, the constitution such that, at the first attaching
side not the second attaching side, in the above-described example,
at the upper attaching portion not the side of the lower attaching
portion, the relative angle between the above-described reaction
frame element and the rear face as the attaching face of the upper
frame element can be changed may be employed. Further, it is
obvious that such a constitution may be used for the both of the
lower attaching portion and the upper attaching portion.
[0065] In addition, the present invention may be used for not only
the backrest of the chair but also for the general regions to
attach one end to the first attaching object via the first
attaching portion and attach other end to the second attaching
object via the second attaching portion in a structure for
attaching spring which is entirely formed in a frame, having one
end connected to a first attaching object and other end connected
to a second attaching object, respectively.
[0066] Other than this, various modifications are possible within
the range without departing from the scope of the present
invention.
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