U.S. patent application number 10/740177 was filed with the patent office on 2004-07-01 for shape-changing support, such as for seating.
Invention is credited to Pekar, Robert W., Teppo, David S..
Application Number | 20040124679 10/740177 |
Document ID | / |
Family ID | 32655819 |
Filed Date | 2004-07-01 |
United States Patent
Application |
20040124679 |
Kind Code |
A1 |
Teppo, David S. ; et
al. |
July 1, 2004 |
Shape-changing support, such as for seating
Abstract
A compliant back for a seating unit includes a rigid upright
defining a track, and a flexible back shell configured to support a
seated user's upper body, including a top pivot pivotally connected
to a top section of the back shell and a pivot/slide member
slidably connected to the track of the back shell. A biasing device
is operably coupled to the pivot/slide member that biases the
pivot/slide member toward a position where the flexible back shell
protrudes forwardly to a shape chosen to optimally support a seated
user.
Inventors: |
Teppo, David S.; (Grand
Rapids, MI) ; Pekar, Robert W.; (Florence,
MA) |
Correspondence
Address: |
PRICE HENEVELD COOPER DEWITT & LITTON, LLP
695 KENMOOR, S.E.
P O BOX 2567
GRAND RAPIDS
MI
49501
US
|
Family ID: |
32655819 |
Appl. No.: |
10/740177 |
Filed: |
December 18, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10740177 |
Dec 18, 2003 |
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09885866 |
Jun 20, 2001 |
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Current U.S.
Class: |
297/284.4 |
Current CPC
Class: |
A47C 7/465 20130101;
A47C 7/462 20130101 |
Class at
Publication: |
297/284.4 |
International
Class: |
A47C 007/46 |
Claims
We claim:
1. A back construction for a seating unit comprising: a back frame
including a rigid upright having top and bottom connections; a
flexible back shell configured to support a seated user's upper
body, including a pivot member pivotally connected to one of the
top and bottom connections and a pivot/slide member slidably
connected to the other of the top and bottom connections; and a
spring operably coupled to a pivot/slide member that biases the
pivot/slide member back shell toward a position where the flexible
back shell protrudes forwardly for optimal lumbar support to a
seated user.
2. A back construction for a seating unit comprising: a back frame
including a rigid upright having top and bottom connections; a
flexible back shell configured to support a seated user's upper
body, the shell being pivotally attached to the back frame at the
top connections and movably attached to the back frame at the
bottom connection; and an energy mechanism being positioned so as
to operably act upon the back shell and cause the flexible back
shell to protrude forwardly for lumbar support to a seated
user.
3. The back construction defined in claim 2, wherein the bottom
connection includes a sliding connector.
4. The back construction defined in claim 2, wherein the energy
mechanism includes one of a spring and bladder.
5. A support apparatus comprising: a shell having a front surface,
and including relatively stiff top and bottom sections separated by
a flexible middle section, the middle section including edge strips
connecting the top and bottom sections, the edge strips being made
of a longitudinally stiff but bendable plastic; a horizontal cross
section through the middle section being forwardly concave so that
the front surface on a center area of the middle section is
positioned rearward of the edge strips, and a vertical cross
section through the middle section being forwardly convex so that
the front surface on the center area of the middle section is
forward of the top and bottom sections; an energy mechanism
positioned vertically on the front surface and across the center
area and having top and bottom ends attached to the top and bottom
sections; the energy mechanism being movable to a constricted
position where the top and bottom ends are pulled toward each other
causing the top, bottom, and center sections to move toward a first
vertical shape; the energy mechanism being movable to a relaxed
elongated position where the top and bottom ends are allowed to
extend from each other causing the top, bottom, and center sections
to move toward a different second vertical shape; whereby, by
constricting and relaxing the energy mechanism, the shell is flexed
between the first and second vertical shapes.
6. The support apparatus defined in claim 5, wherein the first
vertical shape is a more curved vertical shape and the second
vertical shape is a more planar vertical shape.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of application Ser. No. 09/885,866,
filed Jun. 20, 2001, entitled "SHAPE-CHANGING SUPPORT, SUCH AS FOR
SEATING". This application is also related to application Ser. No.
09/885,582, filed Jun. 20, 2001, entitled "COMPLIANT BACK FOR
SEATING UNIT".
BACKGROUND
[0002] The present invention relates to seating units providing a
shape-changing support for a seated user, and more particularly
relates to a back having a flexible lumbar region and lumbar
adjustment mechanism that constricts to change a shape of the
lumbar region. However, the present invention is not believed to be
limited to only backs.
[0003] Many modern chairs often include a lumbar support placed on
a front surface of a back support or integrated into a chair back.
The lumbar support forms a new shape chosen to provide increased
user comfort. Sometimes the lumbar supports are incorporated into
the back, and sometimes they are made vertically adjustable.
However, many of these constructions result in a back construction
that is noticeably thick and heavy in appearance, which is
undesirable in many chair designs. Further, it is preferable that
the adjusting mechanism not merely be an extra device with multiple
pieces assembled onto a back, but instead that it be well
integrated into the back. Also, it is preferable that the
adjustment device be multi-functional and provide more than just
adjustment to the lumbar region of a back, and that it be durable,
long-lasting, and low cost. Still further, it is preferable that
any adjustable lumbar mechanism be easy to adjust and also
intuitive to adjust and use, but that it use few pieces.
[0004] Most chairs last a long time. It is desirable to provide an
adjustable lumbar mechanism that can be sold as an option already
installed on a seating unit, or that can be sold and installed
after the original sale of the chair (i.e. field-installed), and/or
that can be easily removed for cleaning and/or replacement, and yet
that is secure and visually blends in well with the aesthetics and
appearance of the chair.
[0005] Accordingly, an apparatus is desired having the
aforementioned advantages and solving the aforementioned
disadvantages and problems.
SUMMARY OF THE PRESENT INVENTION
[0006] In one aspect of the present invention, a back construction
for a seating unit comprises a back frame including a rigid upright
having top and bottom connections. A flexible back shell is
configured to support a seated user's upper body, including a pivot
member pivotally connected to one of the top and bottom connections
and a pivot/slide member slidably connected to the other of the top
and bottom connections. A spring is operably coupled to a
pivot/slide member that biases the pivot/slide member back shell
toward a position where the flexible back shell protrudes forwardly
for optimal lumbar support to a seated user.
[0007] In another aspect of the present invention, a back
construction for a seating unit comprises a back frame including a
rigid upright having top and bottom connections. A flexible back
shell is configured to support a seated user's upper body, the
shell being pivotally attached to the back frame at the top
connections and movably attached to the back frame at the bottom
connection. An energy mechanism is positioned so as to operably act
upon the back shell and cause the flexible back shell to protrude
forwardly for lumbar support to a seated user.
[0008] In yet another aspect of the present invention, a support
apparatus comprises a shell having a front surface, and includes
relatively stiff top and bottom sections separated by a flexible
middle section, the middle section including edge strips connecting
the top and bottom sections, the edge strips being made of a
longitudinally stiff but bendable plastic. A horizontal cross
section through the middle section is forwardly concave so that the
front surface on a center area of the middle section is positioned
rearward of the edge strips, and a vertical cross section through
the middle section being forwardly convex so that the front surface
on the center area of the middle section is forward of the top and
bottom sections. An energy mechanism is positioned vertically on
the front surface and across the center area and has top and bottom
ends attached to the top and bottom sections. The energy mechanism
is movable to a constricted position where the top and bottom ends
are pulled toward each other causing the top, bottom, and center
sections to move toward a first vertical shape; the energy
mechanism being movable to a relaxed elongated position where the
top and bottom ends are allowed to extend from each other causing
the top, bottom, and center sections to move toward a different
second vertical shape, whereby, by constricting and relaxing the
energy mechanism, the shell is flexed between the first and second
vertical shapes.
[0009] These and other aspects, objects, and features of the
present invention will be understood and appreciated by those
skilled in the art upon studying the following specification,
claims, and appended drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIGS. 1-3 are front, side, and top views of a back
construction including a flexible shell and a removable back
covering incorporating an air bladder adjustment mechanism, the
adjustment mechanism being inflatable to cause a shape change in a
lumbar region of the shell;
[0011] FIG. 4 is an enlarged side view of a bottom portion of the
back shell and bladder in the circled area IV in FIG. 2, the back
frame being removed for clarity;
[0012] FIG. 5 is a front view of a back cover assembly including
the adjustable lumbar support mechanism shown in FIG. 1;
[0013] FIG. 5A is a cross section taken along line IV-IV in FIG. 4,
the air bladder being inflated and in an energized state;
[0014] FIG. 5B is a cross section similar to FIG. 4A, but the air
bladder being uninflated and in a relaxed state;
[0015] FIGS. 5C and 5D are enlargements of the circled areas VC and
VD in FIGS. 5A and 5B;
[0016] FIGS. 6 and 6A are front and side views of a modified back
construction including a permanently-attached inflated/energized
lumbar adjustment mechanism;
[0017] FIG. 6B is a side view similar to FIG. 6A, but with the
bladder deflated;
[0018] FIGS. 7-8 are perspective and side views of another modified
back construction including a permanently-attached
inflated/energized lumbar adjustment mechanism.
[0019] FIG. 9 is a side view similar to FIG. 8, but with the
bladder deflated;
[0020] FIG. 9A is a fragmentary perspective view of an inside of
the rear upright showing details of the slide mechanism in FIGS.
7-9; and
[0021] FIGS. 10-12 are views of another modified back construction,
the views of FIGS. 10-12 being similar to FIGS. 7-9 above.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] The present illustrated back construction 20 (FIG. 1) is
usable in the environment of an office chair having a castored
spider-legged base, a seat, and an underseat control for pivoting
the back 20 and seat with a synchronous motion upon recline of the
back 20. A more detailed description of one such chair can be found
in U.S. Pat. No. 5,975,634, issued Nov. 2, 1999, entitled CHAIR
INCLUDING NOVEL BACK CONSTRUCTION, the entire contents of which are
incorporated herein by reference. Nonetheless, it should be
understood that the present invention is contemplated to be
adaptable for any seating unit or other furniture utilizing a
flexible support.
[0023] The illustrated back 20 of FIG. 1 includes an arching back
frame 25, and a sheet-like flexible plastic back shell 26 pivotally
attached to the back frame 25 at top and bottom locations 33 and 34
(FIG. 2). The general operation and interaction of back shell 26
and back frame 25 are described below in sufficient detail for an
understanding of the present invention, but details can be found in
U.S. Pat. No. 5,975,634, if the reader desires this
information.
[0024] The back shell 26 (FIG. 1) has a "potato chip" like shape,
with its front surface having a horizontal cross section that is
forwardly concave, and a vertical cross section that is forwardly
convex. The back shell 26 has a flexible lumbar region 27
connecting stiff thoracic and pelvic regions 28 and 29. The lumbar
region 27 includes a pair of vertical edge strips 30 and 31, and a
plurality of horizontally extending strips 32 separated by slots
extending between the edge strips 30 and 31 to define a flexible
lumbar area. A belt bracket 35 extends along a lower edge of the
back shell 26, and includes forwardly extending flanges 36 that
define the bottom pivots 34. In U.S. Pat. No. 5,975,634, a biasing
device is provided on the lower pivot to bias the lumbar region
forwardly. In the present construction, a muscle-like air bladder
energy mechanism is provided in a cover assembly 37, as described
below, for changing a shape of the lumbar region 27 of the back
shell 26.
[0025] The cover assembly 37 (FIG. 5) includes a sock-like top
section 38 sewn of upholstery or fabric to define a
downwardly-facing pocket 38' that fits mateably over a top edge of
the back shell 26 (FIG. 1) and onto the thoracic region 28. A
center section 39 of the cover assembly 37 extends downwardly over
a center area of the lumbar and pelvic regions 27 and 29. A stiff
strip 40 is sewn along a bottom edge of the center section 39, and
is shaped to fit mateably into a recess 41' (FIG. 4) in a bottom
edge of the back shell 26 with a zipper-like motion, where it is
frictionally retained. Fasteners can be used for additional
retainment, if desired. It is contemplated that other releasable or
permanent top and bottom attachment devices can also be used.
[0026] A constrictable energy mechanism 39' in the form of a
pleated bladder is attached to the center section 39 (FIG. 5). The
energy mechanism 39' extends vertically downwardly onto a front
panel of the top section 38. The energy mechanism 39' comprises a
laminate (see FIGS. 5C and 5D) with a non-stretchable first inner
layer 41 providing strength and flexibility (such as nylon fiber,
woven fabric, or the like), and second and third layers 42 and 43
that are air impermeable (or fluid impermeable) (such as rubber or
elastomer), and that define a bladder 45 having horizontal cavities
46 (also called "sub-bladders") for receiving air (or other fluid).
(It is noted that instead of horizontal cavities, the cavities can
be round, oval, or other shapes.) As illustrated, a fourth layer 44
similar to layer 41 is provided. It is contemplated that a variety
of different materials can be used to form the bladder, and
further, that different inflating fluids can be used other than
air.
[0027] In the illustrated arrangement, the first and fourth layers
41 and 44 are the outermost and innermost layers, respectively, and
are nylon sheets that allow flexibility but that provide good
strength in directions within the sheets. For example, 200 denier
nylon woven sheeting will work for this purpose. The second and
third layers 42 and 43 are elastomeric film, such as ether-based
urethane, having an 85 Durometer. The layers 41-44 are bonded
together by radio frequency (RF) welding or other bonding technique
around their perimeter to define a bladder. The layers 41-44 are
further bonded together at multiple horizontal pleats 47 (FIG. 6)
that extend partially horizontally across the bladder area to
subdivide the bladder into multiple discrete horizontally-extending
sub-bladders 46 between the pleats. The sub-bladders 46 are
connected at edges by air-communicating edge passages 48. An air
line 49 is attached to the bladder 45, and a hand pump 50 is
attached to the air line 49. The pump 50 can be located at
different locations. As illustrated, the pump 50 (FIG. 6A) is
located along a side of the seat 23, but it could also be located
under an armrest 51 of the chair, under the seat 23, on the back 20
such as at a bottom or at a top in a headrest area, on a base of
the chair, or at other locations. The air pump 50 includes a
flexible bulbous member 51 that can be repeatedly manually squeezed
to pump air through the line 49 into the bladder 45, and further
includes a valve 52 that can be opened to release air from the
bladder through line 49 to atmosphere. It is contemplated that a
powered air pump, such as a battery-powered pump, could be used
instead of a manual pump. Further, a flowable fluid other than air
could be used, such as a liquid pumped from a container under the
seat.
[0028] When deflated or uninflated (see FIGS. 5A and 5C), the
illustrated energy mechanism 39' has a thickness of about 5 mm, and
the pleats 47 are spaced vertically apart about 15 mm to 20 mm, or
more preferably about 19 mm apart. When inflated, each sub-bladder
46 expands from its "linear" shape toward a cylindrical horizontal
shape (see FIGS. 5B and 5D), such that a gross vertical length of
the cover assembly 37 shortens. If the back shell 26 had a flat
horizontal cross section, this shortening of the bladder would
cause the back shell 26 to bend toward a more planar condition.
However, since the edge strips 30 and 31 of the back shell 26 are
forward of the sub-bladders 46, the illustrated back shell 26
actually flexes toward a more curvilinear shape as the sub-bladders
46 are inflated. (Compare FIG. 5A, which has a deep concave shape
shown by dimension T1, and FIG. 5B, which has a shallower concave
shape shown by dimension T2.) Notably, the total surface length of
the outer and inner layers 41 and 44 always stays the same. As a
result, when the bladder 45 is inflated, it reacts much like a
human muscle and shortens. For example, the spacing between pleats
47 changes from a dimension "X" of about 19 mm (FIG. 5D) to a
vertical spacing of about 13 to 15 mm (dimension "Y", FIG. 5C)
(depending on the amount of air pumped into the bladder 45).
[0029] To operate the present invention, the chair 21 is originally
provided with the air bladder 45 not inflated. In this condition,
the back shell 26 has a predetermined curved shape, as determined
by parameters of the chair 21. The cover assembly 37 lies generally
flat against the back shell 26 and provides a small amount of
comfort on a front of the back shell to a seated user. As air is
pumped into the bladder 45, the sub-bladders 46 begin to inflate.
This causes the bladder 45 to shorten in a length direction. In
turn, the back shell 26 is stressed as the bladder 45 shortens and
the edge strips 30 and 31 resist shortening. This causes the back
shell 26 to change its shape and flex toward a more curved shape.
Also, the air provides some additional cushioned support to a
seated user. When air is released from the bladder 45, the process
is reversed, and the back shell 26 moves toward a more linear shape
(which is closer to its natural unstressed shape). It is noted that
the back shell 26 can be made with enough internal strength to flex
toward the relaxed convex shape as shown in FIG. 5A. Alternatively,
a biasing device (such as is illustrated in U.S. Pat. No.
5,975,634, previously incorporated by reference) can be used to
assist in biasing the back shell to its forwardly convex shape. It
is noted that the illustrated bladder 45 acts both to bias the back
shell 26 to a more concave shape, but also combines with the back
shell 26 to act like (and produce lumbar support forces similar to)
a stiffer back shell (26) (e.g. a back shell made of stiffer
material or made with a thicker dimension).
[0030] It is noted that the air in bladder 45 provides both an
energizing system, and also a cushioning action for supporting a
seated user. This multi-functional use has advantages in terms of
comfort to a seated user. If the air is heated, the air bladder has
further functional benefits. It is noted that a liquid can be used
instead of air, if desired. In such case, the liquid could be
stored in a reservoir anywhere on the chair, such as under the
seat, in an armrest, in the back, or in the base of the chair.
[0031] By controlling the vertical spacing of the pleats 47, the
operation of flexing the lumbar region 27 is greatly affected. For
example, closer vertical spacing of the pleats 47 results in a
cover assembly 37 that does not shorten as much as it is filled
with air. In turn, closer spacing of the pleats 47 results in a
lumbar adjustment mechanism that is not able to make as great of a
change to the shape of the lumbar region 27. Also, the back shell
itself can be given different original concave shapes. Thus, the
combined system of the back shell and the cover assembly is
important to overall operation. It is contemplated that the bladder
45 could also be positioned horizontally, instead of vertically,
such that its operation causes a horizontal shape change. Still
further, a horizontal bladder and a vertical bladder (and/or an
angled bladder) can be overlaid or used together to control the
back shape in all directions, or the sub-bladder shapes can be
dome-shaped, elongated but nonlinear (e.g. L-shaped or Z-shaped),
elongated in multiple directions (e.g. X-shaped or Y-shaped), or
any other shape desired.
[0032] A modified back construction 20A is shown in FIGS. 6-6B, a
second modified back construction 20B is shown in FIGS. 7-9 on
chair 21B, and a third modified back construction 20C is shown in
FIGS. 10-12. In these embodiments, all similar or identical
features and components are identified using the same number as
used in back construction 20, but with the addition of a letter
"A", "B", or "C". This is intended to reduce redundant discussion,
and not for another purpose. A person of ordinary skill in the art
will understand that principles discussed in regard to each
embodiment will apply to the other embodiments.
[0033] The modified back construction 20A (FIG. 6) includes a back
shell 26A, a bladder 45A permanently attached to the back shell
26A, and upholstery (not specifically shown) attached over the
bladder 45A and back shell 26A to aesthetically cover the same.
More specifically, the bladder 45A includes top and bottom stiff
edge sections 54A and 55A attached with rivets 56A and 57A. The
bladder 45A includes pleats 47A subdividing it into sub-bladders
46A. The remaining components and operation are identical to or
very similar to the back construction 20, and thus the details will
not be repeated to avoid unnecessary repetition.
[0034] Another modified back construction 20B (FIG. 8) is shown as
part of a chair 21B having a castored spider-legged base 22B, a
seat 23B, the back construction 20B, and an underseat control 24B
for pivoting the back 20B and seat 23B with a synchronous motion
upon recline of the back 20B. In chair 21B, the back construction
20B includes a back frame 25B pivoted to the base 22B under the
seat 23B at pivot location 24B' for reclining movement. A biasing
device, such as a torsion spring, is attached at the pivot location
24B'. A flexible back shell 26B is pivotally attached to a top of
the back frame 25B, but is slidably supported at its lower edge by
a slide member 59B on a lower portion of the back frame 25B. When
inflated, the bladder 45B causes the back shell 26B to flex from
its semi-linear shape (FIG. 9) toward a more curved shape (FIG. 8),
causing the slide member 59B to slide upwardly along the back frame
25B. The back frame (or upright) 25B includes a vertical slot 60B
and a follower 61B attached to a bottom edge of the back shell 26B
is slidably coupled to the slot 60B. Top and bottom ends of the
slot 60B limit flexing of the back shell 26B by engaging the
follower 61B as the back shell 26B is flexed. A spring 72B is
attached between the follower 61B and the top pivot connection 73B
on a top of the back frame 25B. The spring 72B compliments
leaf-spring-like edge strips 30B and 31B to cause the back shell
26B to naturally move toward a curved shape.
[0035] Back construction 20B' (FIG. 9A) replaces the slot 60B and
follower 61B with a channel/track 63B' formed on an inside of the
upright back frame 25B', and an elongated follower 64B' that rides
in the channel/track 63B'. Straps 65B' hold the follower 64B' in
the channel/track 63B', and also act as upper and lower limits as
the shell-attachment brackets 66B' engages them.
[0036] Back construction 20C (FIG. 11) is similar to the back
construction 20B (FIG. 8), except back construction 20C has a
one-piece member 69C with a rigid L-shaped back frame 25C coupled
to the back shell 26C by a living hinge 70C. Also, a hook 71C can
be provided on the lower leg of the L-shaped back frame 25C.
Optionally, hook 71C is designed to hookingly engage a flat member,
such as a bench or bleacher seat in a football stadium.
[0037] It is to be understood that variations and modifications can
be made on the aforementioned structure without departing from the
concepts of the present invention, and further it is to be
understood that such concepts are intended to be covered by the
following claims unless these claims by their language expressly
state otherwise.
* * * * *