U.S. patent number RE36,335 [Application Number 08/786,994] was granted by the patent office on 1999-10-12 for flexible chair.
Invention is credited to Charles O. Perry.
United States Patent |
RE36,335 |
Perry |
October 12, 1999 |
Flexible chair
Abstract
A high density stacking flex chair is disclosed. A frame has a
seat attached thereto, and a back pivotally attached thereto. The
back is curved and can tilt backwards, but is limited by the frame
which, through the back, has a lesser radius of curvature and is
angled downward, thus providing stop action for back rotation.
Inventors: |
Perry; Charles O. (East
Norwalk, CT) |
Family
ID: |
24015733 |
Appl.
No.: |
08/786,994 |
Filed: |
January 23, 1997 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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793357 |
Jan 9, 1992 |
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757734 |
Sep 11, 1991 |
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506716 |
Apr 10, 1990 |
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381151 |
May 2, 1989 |
5009466 |
Apr 23, 1991 |
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185707 |
Apr 25, 1988 |
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Reissue of: |
238415 |
May 6, 1994 |
05383712 |
Jan 24, 1995 |
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Current U.S.
Class: |
297/448.2;
297/239; 297/295; 297/320; 297/342; 297/354.11; 297/447.1 |
Current CPC
Class: |
A47C
1/032 (20130101); A47C 7/44 (20130101); A47C
3/04 (20130101); A47C 3/023 (20130101) |
Current International
Class: |
A47C
7/40 (20060101); A47C 7/44 (20060101); A47C
1/031 (20060101); A47C 1/032 (20060101); A47C
3/04 (20060101); A47C 3/02 (20060101); A47C
3/023 (20060101); A47C 3/00 (20060101); A47C
001/032 () |
Field of
Search: |
;297/239,285,286,288,295-297,320,342,354.11,447.1,448.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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464380 |
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Apr 1946 |
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632397 |
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1249503 |
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CA |
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0 173 372 |
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Jul 1985 |
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EP |
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0 295 214 |
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60468 |
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Apr 1954 |
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FR |
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1196751 |
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May 1959 |
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FR |
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31 00 770 |
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Aug 1982 |
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DE |
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88 021 |
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Oct 1985 |
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DE |
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3635 811 A1 |
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Oct 1986 |
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DE |
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73031 |
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Sep 1984 |
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IL |
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208 410 |
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Jun 1985 |
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NZ |
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220 502 |
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May 1987 |
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NZ |
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610741 |
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Oct 1948 |
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GB |
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754209 |
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Aug 1956 |
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GB |
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Primary Examiner: Brown; Peter R.
Attorney, Agent or Firm: Limbach & Limbach L.L.P.
Parent Case Text
RELATED APPLICATIONS
This application is a continuation of my prior application Ser. No.
793,357, filed Jan. 9, 1992, now abandoned which was a
continuation-in-part of my prior application Ser. No. 757,734 filed
Sep. 11, 1991, now abandoned which was in turn a
continuation-in-part of Ser. No. 506,716 filed Apr. 10, 1990, now
abandoned, which was in turn a continuation-in-part of Ser. No.
381,151 filed May 2, 1989, now U.S. Pat. No. 5,009,466 dated Apr.
23, 1991 which was in turn a continuation-in-part application Ser.
No. 185,707 filed Apr. 25, 1988, now abandoned.
Claims
I claim:
1. A flexible armchair, comprising:
a. a seat adapted to engage a user's seat;
b. a back generally perpendicular to said seat and adapted to
engage a user's back and having a top and a bottom and upper and
lower regions between the top and bottom; and
c. a flexible fame for holding and supporting said seat and back,
characterized by said frame comprising:
i. a pair of support legs one at each side of the seat with each
support leg having,
(1) a resilient back leg portion pivotally connected to the upper
region of said back below the top,
(2) a bottom leg portion for extending along a floor surface,
and
(3) a front leg portion extending upwardly to the front of said
seat to support said seat, and
ii. pivotal connecting means connecting the rear of the seat to the
lower region of said back at a location substantially above the
seat, wherein the flexibility of the frame and the pivotal
connecting means permit the back to tilt toward a reclining
position while the back functions as a lever against the resiliency
of the back leg portion forcing the bottom of the back forwardly
for lumbar support, characterized in that:
d. said back leg portion extends forwardly from said upper region
of said back above the seat and outside the bottom leg portion for
a sufficient distance to form an arm rest and then downwardly and
rearwardly to said bottom leg portion.
2. A high density stacking flexible arm chair as in claim 1
characterized further by the inclusion of stop means for
stabilizing the chair in a stack comprising a pair of tabs on the
front leg portions for engaging the bottom leg portions of an upper
chair in a stack and a strut extending between the rear leg
portions below the seat for engaging the seat of a lower chair in a
stack.
3. A chair, comprising:
a. a seat portion having a shape adapted to engage a user's
seat;
b. a back portion generally perpendicular to said seat portion and
adapted to engage a user's back and having upper, intermediate and
lower regions;
c. a frame for holding and supporting said seat and back portions,
said frame comprising:
i. a pair of rear support legs each pivotally connected to the
intermediate region of said back portion and extending downward to
a floor surface with said rear support legs spaced apart more than
the width of the seat portion; and
ii. a pair of front support legs each pivotally connected to the
lower region of said back portion and extending forward to support
said seat portion, and downward to said floor surface;
whereby the weight of the user urges the back portion to pivot with
respect to the frame toward an erect position and pressure of the
user's back against the upper region of the back portion can pivot
the back portion toward a tilted position.
4. The chair of claim 3, further comprising at least two
stabilizers each attached between respective front and rear support
legs at the floor, such that said front and rear support legs
effectively form a continuous structure.
5. The chair of claim 3, further comprising at least two
stabilizers, one attached between the front support legs and the
other between the rear support legs at a position above said floor
surface.
6. The chair of claim 3, further comprising at least two
stabilizers each attached between any two opposing support
legs.
7. The chair of claim 3, wherein said back portion is curved to
conform to a user's back.
8. The chair of claim 7, wherein said back portion comprises a
front and rear section which are attached together, such that the
attachment of said front and rear support legs to said back portion
is enclosed within said front and rear sections of said back
portion.
9. The chair of claim 8, wherein at the point of attachment of said
rear support legs to said back portion, said rear support legs turn
inward to face each other, and wherein at the point of attachment
of said front support legs to said back portion, said front support
legs turn inward to face each other, and wherein said frame further
comprises:
a. a first curvilinear section attached to each of said rear
support legs at said back portion and extending across the
intermediate region of said back portion at a downward angle,
wherein said first curvilinear section has a radius of curvature
less than that of said back portion, and wherein said back portion
is pivotally attached to said rear support legs and first
curvilinear section;
b. a second curvilinear section attached to each of said front
support legs at said back portion and extending across the lower
region of said back portion at a downward angle, wherein said
second curvilinear section has a radius of curvature less than that
of said back portion.
10. The chair of claim 9, wherein said front and rear sections of
said back portion form a hollow interior space such that said first
and second curvilinear sections have limited clearance within said
space to allow said back portion to be tilted about said first
curvilinear section, such that when a user leans back, thus
exerting rearward pressure on the back portion, said back portion
will tilt at a rearward angle about said first curvilinear section,
such tilting causing said seat portion to raise up in response to
the pulling action exerted on said section curvilinear section.
11. The chair of claim 10, wherein said first and second
curvilinear sections are positioned at a downward angle parallel to
each other and whereby the curvilinear sections provide the pivotal
limits for forward and backward tilting of the back portion, such
that said front section of said back portion abuts and is stopped
by said curvilinear sections when said back portion is in an
upright position, and whereby the tilting of said back portion
causes the interior of the back portion to move away from said
curvilinear sections in a radial fashion, reengaging said
curvilinear sections at an angle determined by the relative radius
of curvatures between said back portion and said curvilinear
sections.
12. The chair of claim 8, wherein said front and rear support legs
are pivotally connected to said back portion through corresponding
openings in the front and rear sections of said back portion.
13. The chair of claim 12, wherein said front and rear sections of
said back portion form a hollow interior space such that said first
and second curvilinear sections have limited clearance within said
space to allow said back portion to be tilted about said first
curvilinear section, such that when a user leans back, thus
exerting rearward pressure on the back portion, said back portion
will tilt at a rearward angle about said first curvilinear section,
such tilting causing said seat portion to raise up in response to
the pulling action exerted on said section curvilinear section.
14. The chair of claim 13, wherein said first and second
curvilinear sections are positioned at a downward angle parallel to
each other and whereby the curvilinear sections provide the pivotal
limits for forward and backward tilting of the back portion, such
that said front section of said back portion abuts and is stopped
by said curvilinear sections when said back portion in an upright
position, and whereby the tilting of said back portion causes the
interior of the back portion to move away from said curvilinear
sections in a radial fashion, reengaging said curvilinear sections
at an angle determined by the relative radius of curvatures between
said back portion and said curvilinear sections.
15. The chair of claim 14, further comprising:
stop means for limiting relative pivotal movement of the back with
respect to the legs between an upright position determined by the
stop means and a reclined position with the back held in the
upright position by the resiliency of the legs.
16. The chair of claim 15, wherein said back has a curved surface,
and said stop means comprises a curved rod connected between the
support legs for pivotal movement with respect to the back as the
back pivots with respect to the legs with the rod having a radius
of curvature less than the radius of curvature of the back and
engaging the back along an elongated common curve, whereby the rod
limits pivotal movement of the back in one direction and permits
limited pivotal movement of the back in the opposite direction.
17. The chair of claim 16, wherein said stop means comprises
a. a first curvilinear section attached to each of said support
legs at the upper region of said back and extending across the
upper region at a downward angle, wherein said first curvilinear
section has a radius of curvature less than that of said back, and
wherein said back is pivotally attached to said support legs and
first curvilinear section, and
b. a second curvilinear section attached to said connecting means
at the lower region of said back and extending across the lower
region at said downward angle, wherein said second curvilinear
section has a radius of curvature less than that of said back, and
said downward angle is equal to about twenty-two degrees.
18. A chair, comprising:
a. a seat portion adapted to engage a user's seat;
b. a back portion generally perpendicular to said seat portion and
adapted to engage a user's back and having upper, intermediate, and
lower regions;
c. a frame for holding and supporting said seat and back portions,
said frame comprising:
i. a pair of support legs which are pivotally connected to the
intermediate region of said back portion and extending downward to
a floor surface, forward along the floor surface, upward to the
front of said seat portion, rearward to support said seat portion,
and upward to attach to the lower region of said back portion at a
location below the attachment of the legs to the intermediate
region of said back portion, said legs diverging outwardly with
respect to the floor surface with the legs spaced apart by more
than the width of the seat portion in order to facilitate
stacking;
ii. a first curvilinear section attached to each of said support
legs at the intermediate region of said back portion and extending
across the intermediate region at a downward angle, wherein said
first curvilinear section has a radius of curvature less than that
of said back portion, and wherein said back portion is pivotally
attached to said support legs and first curvilinear section;
iii. second curvilinear section attached to each of said support
legs at the lower region of said back portion and extending cross
the lower region at said downward angle, wherein said second
curvilinear section has a radius of curvature less than that of
said back portion.
19. The chair of claim 18, wherein said back portion comprises a
front and rear section which are attached together, such that the
attachment of said support legs to said back portion is enclosed
within said front and rear sections of said back portion.
20. The chair of claim 18, wherein said downward angle is equal to
about twenty-two degrees.
21. The chair of claim 18, further comprising a plurality of
stabilizing supports, each connected at right angles between said
pair of support legs.
22. The chair of claim 21, wherein a first stabilizing support
member is located between said pair of support legs in the rear
portion of the frame at the height of the seat portion, and a
second stabilizing support member is located between said pair of
support legs in the front portion of the frame at a height halfway
between the floor surface and the seat portion.
23. A seat back adapted to engage a user's back for use in a chair
which flexes or tilts when a user leans back in said chair, and
support means which are adapted to engage said seat back
comprising:
a. a curved seat back portion;
b. curvilinear means forming part of said support means and having
a radius of curvature less than that of said seat back portion;
c. mounting means for pivotally attaching the seat back portion to
said support means, with interference between the curved seat back
portion and the curvilinear means along matching curves providing
the pivotal limits in both directions for tilting of the seat back
portion.
24. The seat back of claim 23, wherein the tilting of said seat
back causes the seat back portion to move away from said
curvilinear means in a radial fashion, reengaging said curvilinear
means at an angle determined by the relative radii of curvatures
between said seat back portion and said curvilinear means.
25. A seat back for a chair adapted to engage a user's back and
tilt with respect to a support when a user leans back in said
chair, comprising:
a. a curved seat back;
b. a curved rod forming part of said support and having a radius of
curvature less than that of said seat back;
c. mounting means for pivotally attaching the seat back to said
curved rod, with interference between the curved seat back and the
curved rod along matching curves providing the pivotal limits in
both directions for tilting of the seat back.
26. The seat back of claim 25, wherein the tilting of said seat
back causes the interior of the seat back to move away from said
curved rod in a radial fashion, reengaging said curved rod at an
angle determined by the relative radii of curvatures between said
seat back and said curved rod.
27. The seat back of claim 26, wherein the tilting of said seat
back causes the seat back to move away from said curved rod in a
radial fashion, reengaging said curved rod at an angle determined
by the relative radii of curvatures between said seat back and said
curved rod.
28. A chair, comprising:
a. a seat adapted to engage a user's seat;
b. a back generally perpendicular to said seat and adapted to
engage a user's back and having a top and a bottom and upper and
lower regions between the top and bottom; and
c. a flexible frame for holding and supporting said seat and back,
said frame comprising:
i. a pair of support legs one at each side of the seat with each
support leg having,
(1) a resilient back leg portion attached by a first pivotal
connection means to the upper region of said back below the
top,
(2) a bottom leg portion for extending along a floor surface,
and
(3) a front leg portion extending upwardly to the front of said
seat to support said seat, and
ii. second pivotal connection means connecting the rear of the seat
to the lower region of the back at a location substantially above
the seat, the flexibility of the frame and the first and second
pivotal connection means for permitting the back to tilt toward a
reclining position while the back functions as a lever against the
resiliency of the back leg portion forcing the bottom of the back
forwardly for lumbar support.
29. The chair of claim 28 in which the first and second pivotal
connection means at the upper and lower regions of the back
comprise curved struts extending across the back limiting tilting
of the back both toward and away from the reclining position.
30. A chair, comprising:
a seat having an upper horizontal supporting surface adapted to
engage a user's seat;
a back generally perpendicular to said seat and adapted to engage a
user's back and having a top and a bottom and upper and lower
regions between the top and bottom; and
means for holding and supporting said seat and back,
comprising:
a pair of support legs one at each side of the seat with each
support leg having a resilient back leg portion attached by a first
pivotal connection means to the upper region of said back below the
top, a bottom leg portion for extending along a floor surface, and
a front leg portion extending upwardly to the front of said seat to
support said seat, and
a second pivotal connection means connecting the rear of the seat
to the lower region of the back at a location substantially above
the .Iadd.upper horizontal supporting surface of said
.Iaddend.user's seat, the flexibility of the legs and the first and
second pivotal .[.upper horizontal supporting surface of said.].
connection means for permitting the back to tilt toward a reclining
position while the back functions as a lever against the resiliency
of the back leg portion forcing the bottom of the back forwardly
for lumbar support.
31. The chair of claim 30 with the chair back pivotal with respect
to the seat between upright and reclined positions in which at
least one of the pivotal connections means in the upper and lower
regions of the back comprises;
A. a shaft having a pair of coaxial pivot sections each coupled to
opposite sides of the seat back and an intermediate section spaced
apart from the axis of the pivot sections so that the intermediate
section moves with respect to the back as the back and shaft pivot
with respect to each other,
B. stop surfaces on the back spaced apart from the axis of the
pivot sections for engaging the intermediate section to provide
pivotal limits in both the upright and reclined positions, and
C. with the shaft and the resilient back leg portion of the chair
resiliently urging the back into the upright position whereby the
frame is resiliently biased at rest so that the back is in the
upright position and whereby pressure of the user's back against
the chair back causes the back to tilt with respect to the seat
toward, but not beyond the reclined position.
32. A seat back adapted to engage a user's back for use in a chair
having a flexing frame which flexes when a user leans back in said
chair, and support means which are adapted to engage said seat back
comprising:
A. a seat adapted to engage a user's seat,
B. A curved seat back portion adapted to engage the user's back and
pivot with respect to the seat in two directions between an upright
position and a reclined position responsive to the flexing of the
chair,
C. a shaft connected to the frame and having a pair of coaxial
pivot sections each coupled to opposite sides of the seat back and
an intermediate section spaced apart from the axis of the pivot
sections so that the intermediate section moves with respect to the
back as the back and shaft pivot with respect to each other,
D. stop surfaces on the back spaced apart from the axis of the
pivot sections for engaging the intermediate section to provide
pivotal limits in both the upright and reclined positions, and
E. with the shaft and the flexing frame of the chair resiliently
urging the back into the upright position whereby the frame is
resiliently biased at rest so that the back is in the upright
position and whereby pressure of the user's back against the chair
back causes the back to tilt with respect to the seat toward, but
not beyond the reclined position. .Iadd.
33. A chair, comprising:
a seat having an upper horizontal supporting surface adapted to
engage a user's seat;
a back generally perpendicular to said seat and adapted to engage a
user's back and having a top and a bottom and upper and lower
regions between the top and bottom; and
a pair of support legs one at each side of the seat with each
support leg having a resilient back leg portion attached by a first
pivotal connection to the upper region of said back below the top,
a front leg portion extending upwardly to the front of said seat to
support said seat, and an intermediate portion connecting the front
leg portion and the back leg portion;
a second pivotal connection connecting the rear of the seat to the
lower region of the back at a location substantially above the
upper horizontal supporting surface of said user's seat, the
flexibility of the legs and the first and second pivotal
connections permitting the back to tilt toward a reclining position
while the back functions as a lever against the resiliency of the
back leg portion forcing the bottom of the back forwardly for
lumbar support..Iaddend.
Description
BACKGROUND OF INVENTION
This Invention relates to high density stacking chairs of the type
used by hotels for meeting room chairs. Typically, a dolly is
provided which holds a stack of chairs which are stacked as densely
as possible.
The use of low-cost, stacking chairs is well-known in the art.
However, such chairs are designed not with comfort or ergonomics in
mind, but rather to provide a large quantity of temporary seats for
occasional use which can ordinarily be stored and take up minimal
storage space. Such chairs may have some limited flexibility in the
seat back portion, but provide no ergonomic benefits.
Considerable attention has been focused in recent years on better
ergonomic designs, resulting in home and office chairs which
demonstrate a wide variety of designs which include the ability to
recline and provide lumbar support. See, for example, U.S. Pat. No.
4,732,424. Such ergonomic designs do not, however, provide low cost
seating. Thus, it would be desirable to combine the benefits of
ergonomic design into a low cost, stackable chair.
SUMMARY OF INVENTION
I have disclosed a new design for high density stacking chairs
which provides exceptional comfort with exceptional stacking
density by using a flexible frame which flexes to permit partial
reclining of the chair back. At the same time, the partial
reclining of the chair back applies pressure to the user's low
back. This high density stacking flex-chair is available on the
market as the Perry Chair manufactured by the Krueger International
Company of Green Bay, Wis.
In one embodiment of the invention, a single continuous frame has a
seat and a pivoting back attached thereto. Ergometric adjustment of
the chair is accomplished by tilting of the back and flexure of the
frame. Flexure of the frame urges the back into a normal upright
position for stacking and uniform appearance. The back is curved
and hollow, and engages the frame at upper and lower curved
sections of the frame, which sections have radii of curvatures less
than that of the back and which sections are positioned at a
downward angle such that the effective horizontal radii of the
sections in the upright position is shorter than the actual radii,
causing the back to rest against the curved sections and limit
forward tilting of the back. When the back is tilted, the radial
movement disengages the back from the curved sections due to the
difference in radii, until the angle of tilt is such that the
effective radii are again equal and the back again rests against
the curved sections of the frame and limits tilting backward.
In an alternative embodiment of the invention, the high density
flex chair is an armchair. I have accomplished this result simply
by changing the shape of the rear legs so that the chair not only
has the advantage of being an armchair but also has the advantage
that it can be manufactured to some extent with tooling common to
the manufacturing tooling of the armless chair.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a chair built according to the
present invention.
FIG. 2 is a perspective view showing a variation of a chair built
according to the present invention.
FIGS. 3-5 are side plan views showing how the chair back flexes
through its range of backward tilt.
FIG. 6 is a view taken across section 6--6 of FIG. 4 (seat back
omitted) and represents a plan view of the chair according to the
present invention in a partially tilted position.
FIG. 7 is a perspective view of a chair built according to the
present invention.
FIG. 8 is a top plan view (seat back omitted) of a chair built
according to the present invention in the normal rest position.
FIG. 9 is a side plan view of a stack of two chairs according to
the present invention.
FIG. 10 is a rear plan view of the stack of FIG. 9.
FIG. 11 is a perspective view of an alternative embodiment of the
chair of this invention illustrating in phantom a second chair
stacked on top of the first chair;
FIG. 12 is a perspective view similar to FIG. 11 showing the manner
in which the chair of FIG. 11 reclines;
FIG. 13 is a side elevational view of the chair and phantom chair
of FIG. 11;
FIGS. 14 and 15 are top and front elevational views of the chair of
FIG. 11, respectively;
FIG. 16 is in exploded view of the frame of the chair of FIG. 11,
and
FIG. 17 is a detailed view of a part of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, a first embodiment of a chair according to
the present invention is shown. There are three major portions of
the chair: a frame 10, a seat 20, and a back 30. The back 30 is
curved to adapt to a user's back and is composed of a front section
32 and a rear section 34, each of which has a lip 33, 35 or other
spacer which creates a hollow interior space between sections when
they are attached.
The frame 10 is ideally a continuous structure, constructed of
solid rod or tubular steel or the like. Alternatively, it may
consist of welded or otherwise connected sections. The frame 10 has
an upper curved section 12 which is enclosed within the back 30
with cylindrical bearing sections 12a at either end and which
extends through the middle of the back and is angled downward. The
frame 10 then extends from each end of the upper curved section 12
outward from the hollow interior, the back 30 being pivotally
attached thereto at the cylindrical sections 12a. This pivotal
attachment can be accomplished by bearings attached to the front
section 32, but is preferably accomplished by providing bearing
surfaces 12b formed on plastic molded front and back sections 32
and 34.
The frame 10 has a pair of rear support legs 16 which extend
downward and rearward to a floor surface. Bottom legs 17 extend
forwardly along the floor. A pair of front support legs 18 then
extend upward and rearward to the front of the seat 20. The seat
supporting portion 15 extends rearward supporting the seat 20, then
slightly inward, then upward into the back 30, then inward, where
the back is again pivotally attached at pivot connections 14a. The
frame 10 continues to a lower curved section 14 which is enclosed
within the back and which extends through the back at a downward
angle. The distance d.sub.1 between the opposing legs of the frame
10 as it sits on the floor is less than the width d.sub.2 of the
seat 20, so as to facilitate stacking a plurality of such
chairs.
In the embodiment of FIG. 2, the seat supporting portion 15 of the
frame 10 is positioned inwardly from the edges of the seat 20 and
connected by welded struts 22, 23 to improve the support of the
seat and lateral stability of the frame. In FIG. 7, such lateral
stability can be provided by a pair of stabilizers 50, 52.
Additionally, clips 24 are attached to the bottom surface of the
seat 20 in order to easily attach/detach the seat to frame 10.
The back 30 is a one-piece molded unit, having openings or clips 40
which are adapted to pivotally engage the rear support legs 16 at
cylindrical sections 12a. Openings or clips 42 are likewise adapted
to pivotally engage the front support legs 18 at cylindrical
sections 14a. In this way, the back 30 may be easily and securely
fitted to frame 10. The curved sections 12 and 14 remain in a fixed
position relative to frame 10 to provide pivotal limits, as will be
next described.
Referring now to FIGS. 3-5, the tilting action of the back 30 is
illustrated. When the chair is in its upright position, as in FIG.
3, the rear support legs 16 of the frame 10 are inclined at a
forward angle so as to provide a natural spring-type action which
holds the back 30 forward.
The curved sections 12 and 14 of frame 10 are parallel, each
extending outward and downward from the back of the front section
32 at a twenty-two and one-half degree angle. The radii of
curvature for both curved sections 12 and 14 are less than that of
the back portion. But, the radius of curvature of section 12
projected at a plane inclined to the plane of section 12 by an
angle of 22.5 degrees equals the radius of curvature of the back
30, such that the inside of the front section 32 is in contact with
the curved sections 12 and 14 at points 36 and 37 as a result of
the effective radius of the curved sections 12 and 14 being equal
to the radius of the back 30.
As a user leans back on the chair, the front section 32 pivots
about point 50 on the upper curved section, causing the upper half
of the front section to rotate backwards, and the lower half to
rotate forward about point 50. Note also that the seat 20 will be
lifted by the forward rotation of the lower curved section 14.
Since the back 30 has a greater radius of curvature than both
curved sections, the back lifts away from the curved sections as it
is tilted, reengaging the curved sections at points 38 and 39,
located further down the back, where the effective radius of the
back portion is again equal to the radii of the curved sections
after the back has tilted 45 degrees.
A clearer view of the relationship of the curved sections 12 and 14
to the overall frame structure 10 is illustrated in FIG. 6 where
the cylindrical sections of the frame 12a, 14a are providing
straight bearing areas.
Stacking of the chair of the present invention is illustrated with
reference to FIGS. 8-10. As can be seen in FIGS. 8 and 9, the seat
supporting portions 15 of frame 10 are positioned inwardly but
substantially parallel of the floor engaging or bottom portions 17
of frame 10. The rear portions of seat supporting portions 15 are
angled further inward in conformance with the shape of the seat 20,
and then rise upward forming lower curved section 14. The front
portions of seat supporting portions 15 turn downward near the
front of the seat 20 forming front support legs 18. The front
support legs 18 are substantially vertical, thus remaining inward
of the bottom legs 17. However, near the floor each front support
leg 18 is bent outwardly at a slight angle to form into the bottom
legs 17. A stacking tab 19 is welded on the outside near the bend
of each front support leg 18 to provide for indexed stacking of
chairs.
In FIGS. 9 and 10, chair B is stacked on top of chair A. It can be
seen that the front corner of the bottom legs 17B rest on spacing
tabs 19A. Further, rear stabilizer 50B, which has a radius of
curvature similar to the seat 20, rests in the opening between the
seat 20 and back 30. It will be noted that the upper chair B is
offset forwardly from the lower chair A so that the seats of a
stack of chairs will occupy a volume which extends upwardly and
forwardly, and the bottom legs 17 lay outside the volume. Thus, the
bottom legs 17B are wider at the front end thereof than the front
legs 18A and are wider at the rear end thereof than the volume
occupied by the stack of chairs, such that chair A and chair B
stack tightly and neatly.
Referring now to FIG. 11, the chair illustrated therein comprises a
seat 110 and a back 112 which has an upper region 114 and a lower
region 116. The chair has a metal frame which is preferably made of
7/16 inch 1008 steel rod and 5/8 inch steel tube with a 3/32 inch
wall thickness. The rod portion of the frame is generally the same
as the frame of the armless chair with the back and bottom leg
portions replaced by the tube. The frame is pivotally connected to
the upper region of the back at 118 with a pivotal connection 120
between the seat 110 and the lower region 116 of the back 112.
The frame has a pair of legs each having a back leg portion 122, a
bottom leg portion 124 and a front leg portion 126 which are
labeled with the letters "R" and "L" for the right and left legs
with the top of the front legs 126 supporting the seat 110. The
pivotal connections 118 and 120 between the fame and the back 112
are preferably provided by the pivot limiting structure of the
chair which is generally shown in FIGS. 3-5 and the connection
between the frame and the seat 110 is preferably provided in the
same manner as the connections in the commercial armless chair so
that the two chairs can be made with similar manufacturing
tooling.
The chair of this embodiment differs from the chair shown in FIG. 7
in that the back leg portions 122 extend from the pivot connection
118 forwardly generally outside the bottom leg portion 174 for a
sufficient distance to form an arm rest 128 and then downwardly and
rearwardly to the bottom leg portion 124, and the back leg
portions, arms and bottom leg portions are made of tubing which
slips over the rod portion of the frame and is welded to the rod at
welds 121 and 125. Note that there is a slight horizontal bend in
the arm 128, best seen in FIGS. 14 and 16 which position the
forward part of the arm outside the bottom leg portions.
Stops are provided on the chair frame for stabilizing the chair in
a stack. These stops comprise a pair of tabs 130 on the front legs
126 which support the bottom leg portions of an upper chair in the
stack and a cross strut 132 (see particularly FIG. 13) which
engages the top of the seat of a lower chair in the stack.
Preferably the frame also has a metal tab 134 on each chair arm to
which a padded armrest may be attached. As illustrated in FIG. 17,
a slot 136 is provided in the tube to permit the tube to drain
where the frame may be plated after welding.
While several embodiments of the chair of this invention has been
described in the drawings, it will be apparent that certain
modifications may be made thereof within the spirit of the
following claims.
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