FIELD OF THE INVENTION
[0001] The invention relates to an auxiliary chair for use with a chair for gradually improving
the posture by using it routinely, which is like a cushion useful to be placed on
a chair.
THE BACKGROUND ART
[0002] The conventional cushion is constructed of a material and in a configuration intended
to support the buttocks softly, but is not designed with a view to maintaining the
physiological bowing of the backbone. Therefore, when the user sits naturally on a
cushion placed on a flat-seat chair with his or her both soles touching the ground,
his or her pelvises are prone to be bent rearwardly relative to the forward-bending
of the pelvises in the standing posture, in linkage with which the coccyx, sacrum
and backbone will also be rearwardly bent. As a result, the backbone will lose its
physiological bowing, and turn into a rearwardly bent state, so that the weight of
the upper body of the trunk is exerted on the coccyx, ischia and their vicinities,
lower lumbar vertebrae and intervertebral disks, and the thigh's backsides to thereby
increase the burden on the waist and coccyx. In addition, since the user is likely
to assume a posture in which he or she may easily cross the legs, the weight of the
upper body of the trunk exerted on the ischia and their vicinities tends to become
unbalanced to thereby possibly cause strains on the skeleton.
DISCLOSURE OF THE INVENTION
[0003] For the benefit of brevity of the description of the present invention, the auxiliary
chair for use with a chair for improving the posture will sometimes be referred to
simply as "auxiliary chair" in the following description.
[0004] According to this invention, the front center of the concavely curved seat face portion
is recessed in the form of a band extending toward the rear center, and raised portions
gently raised from the lateral sides toward the recessed portion are formed on the
front section of the seat face portion. In the vicinity of the foots of the raised
portions there are formed fan-shaped inclined surfaces gently slanting in an oblique
direction toward the front. The seat including these component elements comprises
a seat formation part. In the center of the bottom of the seat formation part there
is formed a convexly curved portion, on forward and rearward extensions of which there
are formed a front stop portion and a rear stop portion, respectively. It is a seat
formation support part that includes these component elements and supports the seat
formation part from below. These parts are joined together in one-piece and all of
the corners are chamfered, whereby a generally rounded auxiliary chair for use with
a chair for improving the posture is obtained.
[0005] When the user sits on a chair with the use of the auxiliary chair, he or she is urged
to spread out the legs to thereby make it hard to cross the legs. In addition, as
the pressure on the genital organ is alleviated, it is possible to relieve deterioration
of the reproductive capability, oppressive pain of the genital organ, constriction
in the urethra, etc. Moreover, the pelvises are bent forwardly and the physiological
bowing of the backbone is guided, so that the weight of the upper body of the trunk
exerted on the coccyx, the ischia and their vicinities, the lower lumbar vertebrae
and intervertebral disks, and the thigh's backsides are distributed in good balance
to the legs, with the result that the legs will be exercised while at the same time
the burden on the waist and coccyx may be alleviated. Furthermore, since the auxiliary
chair is of such a construction as to make it hard to bring the pelvises into their
rearwardly bent state, the user may be prevented from assuming a posture with his
or her backbone bent rearwardly for a long time. As a result, the user may gradually
improve his or her posture by continuing to routinely use this auxiliary chair placed
on a chair.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Before making a brief description of the drawings, the reference characters and numerals
used in the drawings will be explained below. The character (a) indicates an auxiliary
chair and the character (b) indicates an auxiliary chair devoid of the recessed portion.
The weight reduced auxiliary chair designated by the character 1a used in Figs. 17
and 18 has a configuration and functions similar to those of the auxiliary chair designated
by the character (a) used in Fig. 3. Accordingly, the drawing of Fig. 3 is used to
describe both the auxiliary chair (a) and the weight reduced auxiliary chair 1a. Likewise,
since the weight reduced auxiliary chair devoid of the recessed portion designated
by the character 1b used in Figs. 22 and 23 has a configuration and functions similar
to those of the auxiliary chair devoid of the recessed portion as designated by the
character (b) used in Fig. 19. Accordingly, the drawing of Fig. 19 is used to describe
both the auxiliary chair (b) devoid of the recessed portion and the auxiliary chair
1b which is reduced in weight and is devoid of the recessed portion.
[0007] Figs. 1, 2 and 3 illustrate one mode for carrying out the auxiliary chair according
to this invention, in which Fig. 1 is a cross-sectional view taken in the direction
indicated by the arrows A-A in Fig. 3; Fig. 2 is a cross-sectional view taken in the
direction indicated by the arrows B-B in Fig. 3 and Fig. 3 is a top plan view showing
the posture-improving auxiliary chair (a) for use with a chair being tilted forwardly
to a maximum;
[0008] Figs. 4, 5 and 6 illustrate the auxiliary chair (a) according to this invention depicted
from the various angles, in which Fig. 4 is a side view of the auxiliary chair (a);
Fig. 5 is a front view showing the auxiliary chair (a) being tilted forwardly to a
maximum; and Fig. 6 is a perspective view showing the auxiliary chair (a) being tilted
forwardly to a maximum;
[0009] Before describing the drawing of Fig. 7, the reference characters and numerals used
in Fig. 7 will be explained. The character (E) indicates a tangent line with the point
21 on the seat face portion of the auxiliary chair (a) as an apex; the character (F)
indicates a tangent line with the point 22 on the seat face portion of the auxiliary
chair (a) as an apex; the character (G) indicates a tangent line with the point 23
on the seat face portion of the auxiliary chair (a) as an apex; the character (X)
indicates an angle between the tangent line (E) and the seat face portion 24; the
character (Y) indicates an angle between the tangent line (F) and the seat face portion
24; and the character (Z) indicates an angle between the tangent line (G) and the
seat face portion 24; Fig. 7 is to show the comparison between the angles of the seat
face portion of the auxiliary chair (a) tilted forwardly to a maximum on a flat seat
chair at the points 21, 22 and 23;
[0010] Figs. 8, 9, 10, 11, 12 and 13 show examples of use of the auxiliary chair (a) according
to this invention, in which Fig. 8 is a side view showing the user being seated on
the auxiliary chair (a) in the center thereof with his legs closed together; Fig.
9 is a side view showing the user being seated on the auxiliary chair (a) toward the
front thereof with his legs closed together; Fig. 10 is a side view showing the user
being seated on the auxiliary chair (a) toward the rear thereof with his legs closed
together; Fig. 11 is a front view showing the user being seated on the auxiliary chair
(a) in the center thereof with his legs closed together; Fig. 12 is a front view showing
the user being seated on the auxiliary chair (a) in the center thereof with his legs
spread out; and Fig. 13 is a side view showing the user being seated on the auxiliary
chair (a) in the center thereof with his legs spread out;
[0011] Fig. 14 and Figs. 15 and 16 show a cushion and the auxiliary chair (a), respectively
placed on a flat seat chair and the user being seated on the cushion and the auxiliary
chair (a), respectively with his or her pelvises bent rearwardly, in which Fig. 14
is a side view showing the cushion placed on the flat seat chair and the user being
seated with his pelvises rearwardly bent; Fig. 15 is a side view showing the auxiliary
chair (a) being tilted rearwardly and the user being seated with his pelvises rearwardly
bent; and Fig. 16 is a front view of Fig. 15;
[0012] Figs. 17 and 18 show a weight-reduced form of the auxiliary chair (a) according to
the present invention, in which Fig. 17 is a cross-sectional view taken in the direction
indicated by the arrows A-A in Fig. 3 and Fig. 18 is a cross-sectional view taken
in the direction indicated by the arrows B-B in Fig. 3;
[0013] Figs. 19, 20 and 21 illustrate still another mode for carrying out the auxiliary
chair of the present invention, in which Fig. 19 is a top plan view showing the auxiliary
chair (b) being tilted forwardly to a maximum; Fig. 20 is a cross-sectional view taken
in the direction indicated by the arrows C-C in Fig. 19 and Fig. 21 is a cross-sectional
view taken in the direction indicated by the arrows D-D in Fig. 19; and
[0014] Figs. 22 and 23 show a weight-reduced form of the auxiliary chair (b) of the present
invention, in which Fig. 22 is a cross-sectional view taken in the direction indicated
by the arrows C-C in Fig. 19 and Fig. 23 is a cross-sectional view taken in the direction
indicated by the arrows D-D in Fig. 19.
BEST MODES FOR CARRYING OUT THE INVENTION
[0015] The present invention will now be described in details with reference to the accompanying
drawings.
[0016] Figs. 1, 2 and 3 illustrate one embodiment of carrying out the auxiliary chair according
to the present invention, which is a one-piece auxiliary chair (a) comprising a seat
formation part 1 on which a person sits and a seat formation support part 5 bonded
to the seat formation part 1 for supporting it from below.
[0017] The seat formation part 1 may be formed of rubber, wood, steel, plastic, resin, corrugated
cardboard and other materials comfortable in seating, moderately hard and having reversibility
or restorability.
[0018] The seat face portion 6 is smoothly and concavely curved from the rear toward the
front in order to enhance fitness feeling for the buttocks, to facilitate guiding
the forward-bending of the pelvises, and to make it possible for the user to select
the forward-bending angle of the pelvises depending on his or her seating position.
The degree of the curvature of the seat face portion 6 may be varied as required since
the forward-bending angle of the pelvises in the standing posture delicately varies
depending on the age, individual difference and the race.
[0019] The recessed portion 7 is recessed in the form of a band extending from the front
center of the seat face portion toward the rear center thereof in order to relieve
the pressure on the genital organs and coccyx. The width and depth of the recessed
portion 7 may be varied as required since the size of the genital organs and coccyx
varies from person to person.
[0020] The front section of the seat face portion 6 is gently raised from the lateral sides
thereof toward the recessed portion 7 to form raised portions 10, in order to retain
the roots and their vicinities of the inner portions of the thighs to urge both legs
to spread out to thereby prevent the upper body of the trunk from leaning excessively
forwardly as well as to prevent the seated position from creeping. The size and height
of the raised portions 10 may be varied as required.
[0021] The thigh's backside rests 11 formed in the vicinity of the foots of the raised portions
10 are fan-shaped inclined surfaces gently slanting in an oblique direction toward
the front which are designed to facilitate guiding the forward-bending of the pelvises
and to smoothly transfer the weight of the upper body of the trunk to the legs. The
degree of the starting point of inclination, the angle of inclination and the extent
of the thigh's backside rests 11 may be varied as required since the size of the buttocks,
the spacing between the ischia, the excursion of the hip joints, the size of the thighs,
etc. vary from person to person.
[0022] The front edge 12 is moderately curved in order to relieve the pressure on the nerves
and blood vessels passing through the thighs' backsides.
[0023] The front section 13, the rear section 14 and the side section 15 are smoothly inclined
from the seat formation part 1 toward the bottom of the seat formation support part
5.
[0024] The seat formation support part 5 may be formed of rubber, wood, steel, plastic,
resin, corrugated cardboard and other hard materials less deformable under the weight
of the upper body of the trunk when seated.
[0025] The bottom curved portion 16 is moderately convexly curved in order to facilitate
forward- and rearward-bending of the pelvises. It should be noted, however, that the
bottom curved portion 16 is curved only in forward and rearward directions but not
in transverse directions in order to make the weight of the upper body of the trunk
exerted on the ischia and their vicinities approach to uniformity and to bring the
heights of the left and right pelvises into uniformity. Consequently, the auxiliary
chair (a) is capable of swinging or tumbling only in forward and rearward directions.
The degree of curvature of the bottom curved portion 16 may be varied as required.
[0026] The front stop portion 17 lies forwardly on an extension of the bottom curved portion
16 and acts to prevent the auxiliary chair (a) and the upper body of the trunk from
leaning forwardly excessively. The rear stop portion 18 lies rearwardly on an extension
of the bottom curved portion 16 and acts to prevent the user from falling rearwardly.
While the front stop portion 17 and the rear stop portion 18 are basically of a planar
shape, they may be varied in shape as required depending upon the material or configuration
of the seat formation part of used chair.
[0027] Figs. 4, 5 and 6 are side, front and perspective views of the auxiliary chair (a)
drawn to assist in visual understanding of the present invention as viewed from the
various angles.
[0028] From Fig. 4 it is seen that the seat face portion 6 is gently curved, the front section
13 is smoothly inclined from the seat face portion 6 toward the front stop portion
17, and that the rear section 14 is smoothly inclined from the seat face portion 6
toward the rear stop portion 18.
[0029] Seen from Fig. 5 are the thigh's backside rests 11 gently slanting an oblique direction
toward the front, the location and the degree of projection of the raised portions
10 and the location and the breadth of the recessed portion 7.
[0030] Seen from Fig. 6 are the recessed portion 7 in the form of a band extending from
the front center of the seat face portion of the auxiliary chair (a) toward the rear
center thereof, and the depth of the recess is noted from the bottom 8 and the side
walls 9 of the recessed portion.
[0031] Fig. 7 shows, from the side, the angles between tangent lines E, F and G which are
tangent to the seat face portion 6 of the auxiliary chair (a) at points 21, 22, and
23, respectively as apexes lying on the seat face portion 6 and the seat face portion
24 of a chair having a flat seat, when the auxiliary chair (a) is tilted forwardly
to a maximum on the flat seat chair. The angles between X, Y and Z, respectively of
the tangent lines E, F and G tangent to the seat face portion 6 of the auxiliary chair
(a) at the points 21, 22, and 23 as apexes lying on the seat face portion 6 and the
seat face portion 24 of the flat seat chair are such that X<Y<Z. Consequently, when
a user with no impediments in the backbone and pelvises is seated on the auxiliary
chair (a) tilted forwardly to a maximum, the forward-bending angle of the pelvises
increases as the seating position is moved to the rear.
[0032] Figs. 8, 9, 10, 11, 12 and 13 illustrate examples of use of the auxiliary chair (a).
The examples of use will be described below.
[0033] Preferably, a chair 25 on which the present invention is to be used includes a seat
26 having a seat area at least equal to that of the auxiliary chair (a) which is preferably
planar without being inclined rearwardly, having a hardness allowing for swinging
or tumbling of the bottom curved portion 16, and having a height such that the user
27 may sit on the auxiliary chair (a) on the seat with his both soles 28 positively
resting on the ground.
[0034] The method of using the present invention comprises first placing the auxiliary chair
(a) on the chair 25 with the front edge 12 of the auxiliary chair (a) oriented toward
the front edge 29 of the seat 26 of the chair 25 on which the user is going to sit.
However, it should be noted that the front edge 12 of the auxiliary chair (a) must
not extend beyond the front edge 29 of the seat 26 of the chair 25 being used.
[0035] The user 27 sits slowly with his buttocks 30 resting on the center of the auxiliary
chair (a), his legs 31 closed together, his both soles 28 securely touching the ground,
and his pelvises 32 forwardly bent, as shown in Fig. 8. Fig. 11 shows this state in
a front view. Here, if it is desired to mitigate the forward-bending of the pelvises,
the user moves his buttocks 30 toward the front of the auxiliary chair (a) whereupon
he bends his pelvises 33 forwardly as shown in Fig. 9. If it is desired to increase
the forward-bending of the pelvises, the user moves his buttocks 30 toward the rear
of the auxiliary chair (a) whereupon he bends his pelvises 34 forwardly as shown in
Fig. 10. Once the seating position has been determined, the user spreads out his legs
31 with his soles 28 opening forwardly in an inverted V shape and is thus seated bracing
both legs securely as shown in Fig. 12. From Fig. 12 it is seen that the roots and
their vicinities 35 of the inner portions of the thighs are pressed up by the raised
portions 10 and the pressure against the male genital organ 36 is relieved. Fig. 13
shows this state in a side view. In addition, the user is also able to sit on the
auxiliary chair (a) while keeping his balance on the bottom curved portion 16.
[0036] Fig. 14 is a side view showing that the user 27 sitting on a cushion 37 placed on
the flat seat chair 25 on which the present invention is to be used, with his legs
31 spreading out, his both soles 28 resting on the ground and his pelvises 38 rearwardly
bent. Fig. 15 is a side view showing that the auxiliary chair (a) is placed on said
flat seat chair 25 and that the user 27 sits astride the auxiliary chair (a) with
his both soles 28 touching the ground and his pelvises 39 rearwardly bent. Fig. 16
shows this state in a front view. With reference to Figs. 14, 15 and 16, the differences
therebetween will be described below.
[0037] When the user 27 is seated in a posture as shown in Fig. 14, his pelvises 38 will
be rearwardly bent, whereupon his coccyx 40, sacrum 41 and backbone 42 will also be
rearwardly bent. Consequently, the weight of the upper body of the trunk bears on
the coccyx 40, ischia and their vicinities 43, the lower lumbar vertebrae 44 and intervertebral
disks 45, and the thigh's backsides 46. As a result, if the user continues to have
such posture for a long time or a long period of time, the burden on the lumbar region
47 and coccyx 40 will be aggravated, so that the user's own physiological bending
of the back bone may possibly change gradually into rearward bending.
[0038] Next, when the user 27 is seated in a posture as shown in Fig. 15, his pelvises 39
will be rearwardly bent, whereupon the front section of the auxiliary chair (a) is
lifted up and consequently the thighs 48 are also lifted up. In an attempt to keep
his sitting posture, however, the user 27 will lean forwardly the upper body tending
to fall rearwardly, whereupon the rearward-bending of the backbone 42 and the extension
of the muscle of back 49 shown in Fig. 15 will be greatly aggravated as consequently
will the contraction of the abdominal muscle 50 also be greatly aggravated. As a result,
the user 27 may easily restore the posture as shown in Fig. 13 that is an anteverted
posture which exerts a less burden on his abdominal muscle 50.
[0039] Figs. 17, 18, 19, 20, 21, 22 and 23 illustrate still other modes for carrying out
the present invention.
[0040] The weight reduction of the auxiliary chair (a) is made possible by varying the thickness
of the seat formation part 1 and hollowing out the interior of the auxiliary chair
(a). The reference numeral 19 in Fig. 17 shows the hollow interior of the auxiliary
chair (a). However, as a result of the hollowing out, the seat formation part 2 may
possibly be deformed due to the weight of the upper body of the user's 27 trunk, depending
on the material of which the seat formation part 2 is made. For this reason, support
bars 20 to support the seat formation part 2 are inserted in the hollow interior 19.
The support bars 20 may be made of the same material as the seat formation support
part 5 and be joined with the seat formation part 2 and the support part 5 in the
hollow interior 19. The shape and the number of the support bars 20 may be varied
as required.
[0041] Figs. 19, 20 and 21 illustrate yet another embodiment for carrying out the auxiliary
chair according to the present invention.
[0042] This auxiliary chair (b) is intended to be used mainly by women who suffer less pressure
on their genital organs from the seats. The raised portion 10 on the front section
of the auxiliary chair (b) is gently raised from the lateral sides toward the center
of the front section of the auxiliary chair (b) . The description on the rest of the
best mode for carrying out the invention of the auxiliary chair (b) is the same as
that already made hereinbefore on the best mode for carrying out the present invention
excluding the description of the recessed portion.
[0043] Figs. 22 and 23 are cross-sectional views of a weight-saved auxiliary chair 1b. The
weight reduction of the auxiliary chair (b) is achieved in a similar manner to the
manner of weight reduction described hereinabove in the passage on page 11 lines 1-12
in connection with the auxiliary chair (a).
[0044] The auxiliary chair of the present invention is provided over its entire surface
with nonslipping treatment in order to prevent the seated position from creeping when
the user is seated in his or her selected position as well as to prevent the orientation
of the auxiliary chair as placed on the chair from becoming displaced and further
to enhance the function of the front stop portion 17 and the rear stop portion 18.
In addition, the auxiliary chair has all its corners chamfered in order to enhance
the safety. Therefore, the auxiliary chair becomes rounded shape as a whole. Further,
it is a matter of course that the size of the auxiliary chair of the present invention
may be varied without departing from the essential characteristics thereof as individual
persons differ in their physiques from person to person. Moreover, this auxiliary
chair is applicable as a seat for various types of chairs.