Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02470488 2004-06-07
CHAIR BACK FOR A CHAIR
Field of the Invention
This invention relates in general to chair backs and more particularly to a
chair back
for a chair having a frame and a removable mesh knitted sock or sleeve that
can
accommodate different shaped backs and is held in place on the chair frame via
the tension
within the knitted sock and the structure of the chair fia.me therefore not
requiring fasteners.
Background of the Invention
Chair backs have traditionally included components such as wood or metal
supports,
some form of padded composite, and upholstery, so as to form a chair back that
then provides
support as well as a pleasing look. Typically a chair back has included a
support frame that
can be a rigid panel, followed by padding or stuffing that is then covered by
fabric. The
fabric can be positioned and secured a number of ways to support the frame.
The support
frame defines the shape of the chair back and can be a wide variety of shapes.
The shape of
the chair back however has to be sufficient so that there is sufficient
support in the middle of
the chair back for the user to lean against. The top of the chair back can be
narrower or wider
than the middle of the chair, but traditionally the bottom portion of the
chair is the same
width as the middle portion of the chair back.
The usual assembly of the chair back requires the fabric to be pulled over the
padding
or stuffing like a sleeve, pocket or soc that is shaped to the general shape
of the chair back
and is open at one end, usually the bottom end. Therefore the sleeve opening
is fit over the
top end of the chair back and then pulled down over the middle portion of the
chair back to
the bottom portion. The open end of the sleeve is then closed by stapling or
fastening the
ends of the sleeve to the bottom portion of the chair. This is usually
facilitated by having a
piece of wood mounted to the bottom of the chair back so that stapling of the
fabric can be
done fairly expeditiously. As such, there are limitations as to the shape of
the bottom portion
of the chair back so as to avoid either having excess material at the bottom
portion of the
chair or not being able to fit the sleeve over the middle portion of the chair
back if the bottom
portion was smaller or narrower than the middle portion.
Prior art chair backs have been devised to address some of the aforenoted
problems of
attaching fabric to a support frame for a chair. Fox example, United States
Patent No.
CA 02470488 2004-06-07
-2-
6,120,097 issued on September 19, 2000 to Perry et al. and relates to a
flexible chair which
includes a seat frame having a bidirectional fabric stretched over the seat
frame to define seat
back and seat bottom portions. The seat frame is supported on an upper axis
and a lower axis
by a flexible frame. The fabric cover 116 is preferably a single piece of
bidirectional mesh
fabric, such as high density two-way stretch woven cloth. The fabric may be
cut to
appropriate size, then the seat frame I IO inserted as components into
openings or pockets
provided in the sewn fabric pattern and completed as described below.
Alternatively, the
fabric may be stretched over the completed seat frame and heated to shrink the
fabric to the
frame using well known techniques. Referring to FIG. 5, the seat frame 110 is
preferably
constructed by assembling front section 111, mid-sections l I2L and 1128, and
top section
114, after insertion of these sections into pockets sewn into the fabric
cover. These sections
are preferably five-eighths inch steel tube IOI, formed or bent to shape. As
shown in FIG.
6A, front section 111 preferably includes a support bar I l la attached to the
middle of section
11 l, for example, by weldment, to provide additional support against sagging
of the fabric
cover 1 I6. Support bar 11 la can be a smaller diameter steel, for example,
three-eighths inch.
As shown in FIG. 6B, each section of tube 101 is inserted into a corresponding
pocket 102
formed in the fabric cover 116A, for example, by wrapping the fabric and
sewing on seam
103, as shown. The location of seam 103 is left to design preference, but if
left out from the
end about five or six inches, then pockets are formed which are suitable to
accommodate
foam inserts, or support bar 11 Ia.
U.S. Patent No. 5,393,126 which issued on February 28, 1995 to Boulva and
relates to
a composite support frame structure for the construction of a seat. The
support structure
comprises a rigid continuous rod-like frame formed in a closed loop and having
opposed
diverging rod-like side members which lie in a common plane and opposed rod-
like end
members formed integral with the side members. At least one of the end members
is arced
outwardly. A belt of substantially non-extensible material forms a slightly
truncated sleeve,
narrower that the frame, to apply a compression force between the side members
and to flex
the arced end member. The sleeve is retained in tension about the opposed
diverging rod-like
side members by restoring spring force between the side members exerted by the
arced end
member.
U.S. Patent No. 4,230,365 which issued on October 28, 1980 to and relates to
Messinger an article of furniture, and a method for making same, the furniture
comprising a
self supporting peripheral frame, having an open central region, and a fabric
sleeve, covering
CA 02470488 2004-06-07
_3_
said peripheral frame and providing a body support surface. The peripheral
frame, which
comprises two side rail members and a plurality of braces connecting the rail
membexs,
defines a body contour. The fabric sleeve may be impregnated with a resinous
material,
thereby providing a substantially rigid body support surface, or padding may
be disposed
between the fabric sleeve and the peripheral frame, thereby providing a softer
body support
surface. The fabric sleeve may be a one-piece, two-way stretch member, such as
different
types of knitted materials or a non-stretch member of different types of woven
materials. The
article of furniture may be formed as a chair, a lounger or recliner or a foot
rest. The articles
of furniture are easily shaped in keeping with the requirements of the human
body by
stretching the fabric over a designed contour, thereby providing an
inexpensive means for
producing customized furniture on a large scale.
U.S. Patent No. 6,508,509 which issued on January 21, 2003 to Peterson and
relates to
a seating unit illustrated as a mobile office chair includes a base, a back
upright operably
supported on the base for reclining movement and a back construction. The back
construction includes a cushion assembly attached to a back support shell with
quick-attach
top and bottom connectors. Specifically, the back support shell includes top
apertures, and
the cushion assembly includes hooks for drop-in attachment to the top
apertures. The back
support shell also includes a molded bottom section defining a recess, and the
back cover
includes a stiffened edge flange configured to fiictionally engage the recess
to retain the back
cover to the back support. The cushion assembly includes a cover assembly with
an
upholstered front panel, and a rear panel formed by a first sheet section
having a one-
directional stretch in a vertical direction, and a second section having a
high-stretch property.
U.S. Patent No. 6,478,381 which issued on November 12, 2002 to Crarnb, III et
al.
and relates to a vehicle seat assembly is provided having a seat bottom and a
seat back
assembly connected to the seat bottom. The seat back assembly includes a
support frame
having a pair of opposing substantially vertical side frame members which
receive an
elastomeric support webbing. The elastomeric support webbing extends between
the
opposing substantially vertical side frame members to provide structural
support for the
passenger of a vehicle. Side bolsters are attached to the elastomeric support
webbing about
the opposing substantially vertical side flame members. A headrest or upper
bolster is
secured to the top of the frame of the seat assembly adjacent the side
bolsters.
CA 02470488 2004-06-07
-4-
Prior art chair backs or support devices however do not address issues of
attaching
fabric to a support frame without fasteners, while applying the fabric to a
variety of different
shaped backs. More specifically prior art devices do not address the ability
for attaching a
fabric on to a chair back that is shaped identically at both the top and
bottom of the chair back
therefore not requiring that the bottom of the chair back be a place for the
attachment of the
fabric. Typically prior art devices can accommodate a chair back that may be
narrow at the
top but not at the bottom since the pocket of fabric would either not fit over
the middle
portion of the chair or the fabric would be able to fit over the middle
portion of the chair but
sag around a narrow bottom portion. Thus a mesh chair back having a frame and
a
removable sleeve that can accommodate different shaped backs and is held in
place on the
chair frame via the tension within the knitted sock and the structure of the
chair frame and not
requiring fasteners which is desirable.
Summary of the Invention
An object of one aspect of the present invention is to provide an improved
chair back
for a chair having a frame and a removable mesh knitted sock or sleeve that
can
accommodate different shaped backs and is held in place on the chair frame via
the tension
within the knitted sock and the structure of the chair frame therefore not
requiring fasteners.
In accordance with one aspect of the present invention there is provided a
chair back
for a chair that includes a support frame portion having a defined shape and
is adapted to
attach to a chair base member. The chair back for a chair may also include a
tensioning
frame portion having a defined shape and a removable elastomeric support
sleeve having an
opening adapted to receive the defined shape of the support frame porkion and
the defined
shape of the tensioning frame portion. The removable elastomeric support
sleeve may be
slid first over the support frame portion so as to conform the removable
elastomeric support
sleeve to the defined shape of the support frame portion. The removable
elastomeric support
sleeve may then be slid second over the tensioning frame portion thereby
conforming the
elastomeric support sleeve to the defined shape of the tensioning frame
portion. The support
frame porkion may be adapted to receive and secure the tensioning frame
portion, so that the
force of connecting the tensioning portion to the support frame portion locks
the defined
shape of the support frame portion and the defined shape of the tensioning
frame portion to
one another along with the removable elastomeric support sleeve and therefore
forms the
chair back.
CA 02470488 2004-06-07
-S-
Conveniently, the opening of the removable elastomeric support sleeve is
positioned
at a point on the removable elastomeric support sleeve which has the greatest
width. The
defined shapes of the support frame portion and the tensioning frame portion
may be mirror
images of themselves or tensioning frame portion may be larger in size.
Furthermore a method of assembling a chair back for a chair is provided and
includes
sliding a removable elastomeric support sleeve having an opening over a
support frame
portion having a defined shape and adapted to attach to a chair base member of
the chair.
Conforming the removable elastomeric support sleeve to the defined shape of
the support
frame portion. Sliding the removable elastomeric support sleeve over a
tensioning frame
portion having a defined shape. Conforming the removable elastomeric support
sleeve to the
defined shape of the tensioning frame portion. Locking the tensioning frame
portion to the
support frame portion as the support frame portion is adapted to receive and
secure the
tensioning frame portion. Tensioning the removable elastomeric support sleeve
from the
force of connecting the tensioning frame portion to the support frame portion
thereby forming
the chair back.
Advantages of the present invention are: the arrangement of the removable
elastomeric support sleeve with the support frame portion and the tensioning
frame portion
allows for the chair back to be a variety of shapes; no fasteners or
mechanical attachments are
required for attaching the removable elastomeric support sleeve to the frame
portions; trim
and/or covers are not required to hide fasteners; the elastomeric support
sleeve is easily
removable to change colour; easy to install in the field and for servicing;
the tensioning and
support frame portions can be shaped into various design chair backs; the
defined shapes of
the support frame and tensioning frame portions can be made from a variety of
material such
as metal tubing so long as the two frame portions can fit together; the
removable elastomeric
support sleeve may be shaped to accommodate both the tensioning frame portion
and the
support frame portion via an opening that is conveniently positioned at the
widest point on
the chair back shape and can accommodate a removable lumbar support; the
tensioning of the
removable elastomeric support sleeve for the chair back occurs automatically
as soon as the
tensioning frame portion and the support frame portion are locked together;
and the structure
of the support frame portion allows for support for the chair back to occur
all the way to the
mid-point of the chair back rather than from the chair base member thereby
allowing the
structure of the support frame portion to be partially made from a thinner
tubing and therefore
result in a thinner profile.
CA 02470488 2004-06-07
-6-
Brief Description of the Drawings
A detailed description of the preferred embodiment is provided herein below by
way
of example only and with reference to the following drawings, in which:
Figure 1 in a partial exploded view, illustrates a chair back for a chair in
accordance
with the preferred embodiment of the present invention;
Figure lA in a side view, illustrates the removable elastomeric support sleeve
of the
chair back of Figure 1.
Figure 2 in a back perspective view, illustrates the chair back showing the
insertion of
the lumbar support of Figure 1.
Figure 3 in a perspective view, illustrates the chair back of Figure 1.
Figure 4 in a side elevation view, illustrates the chair back of Figure 1.
Figure 5 in a front elevation view, illustrates the chair back of Figure 1.
Figure 6 in a back elevation view, illustrates the chair back of Figure 1.
In the drawings, preferred embodiments of the invention are illustrated by way
of
example. It is to be expressly understood that the description and drawings
are only for the
purpose of illustration and as an aid to understanding, and are not intended
as a definition of
the limits of the invention.
Detailed Description of the Preferred Embodiment
Referring to Figures l, and 3 there is illustrated in perspective views, a
chair back 10
for a chair 12 in accordance with a preferred embodiment of the present
invention. The chair
back 10 for a chair 12 includes a support frame portion I4 having a defined
shape 16 and is
adapted to attach to a chair base member 18. The chair back 10 for the chair
12 may also
include a tensioning frame portion 20 having a defined shape 22 and a
removable elastomeric
support sleeve 24 having an opening 26 adapted to receive the defined shape 16
of the
support frame portion 16 and the defined shape 22 of the tensioning frame
portion 20.
Referring to Figures l and 6 the support frame portion 14 may be further
defined to
include a Y-shaped portion 28 that attaches the support frame portion 14 to
the chair base
CA 02470488 2004-06-07
-7-
member 18, and a support member 30 that is mounted to the Y-shaped portion 28.
The
support member 30 engages the removable elatomeric support sleeve 24 when the
chair back
is assembled. The positioning of the Y-shaped portion 28 allows the chair back
10 to have
support beyond the chair base member 18 and up to at least the mid-point of
the chair back
5 10. This advantageous positioning provides extra structure to the chair back
10 and therefore
allows for the support member 30 to be a thinner structure which in turn
enhances the profile
of the chair 12. In general the Y-shaped portion 28 may be made from hollow
metal tubing
that is shaped to provide two openings 32 at first and second ends 34 and 36
respectively of
the Y-portion 28. In general the support member 30 may be made from metal
tubing that is
10 generally smaller in diameter than the tubing used for the Y-shaped portion
28 so as to
provide a thinner profile to chair back 10 (Figure 4). The support member 30
to attached to
the Y-shaped portion 28 via well know methods in the art such as welding.
Referring to Figure 1, the tensioning frame portion 20 may be further defined
as
having a first end 38 and a second end 40 which are adapted to fit into the
two opening 32 at
the first and second ends 34 and 36 of the Y-shape portion 28. More
specifically the first end
38 and second end 40 may further include rubber bushings 42 to provide a
friction fit of the
tensioning frame portion 20 into the support frame portion 14. The support
frame portion 14
and the tensioning frame portion 20 may made from a variety of appropriate
materials, like
metal or composites and the like as long as the ends 38 and 40 of the
tensioning frame portion
fit into the two opening 32 of the support frame portion 14.
Referring to Figures 1A and 5 the removable elastomeric support sleeve 24 may
have
front side 42, a back side 44, a top region 46 and a bottom region 48 and may
be shaped in a
variety of shapes to accoW modate the defined shapes 16 and 22 of the support
frame portion
14 and the tensioning frame portion 20. More specifically the opening 26 must
be positioned
at the point on the removable elastomeric support sleeve 24 that is the widest
on the shape of
the removable elastomeric support sleeve 24. The positioning of the opening 26
at the widest
point ensures that the elastomeric support sleeve 24 will fit over either the
defined shape 16
of the support frame portion 14 or the defined shape 22 of the tensioning
frame portion 20.
This configuration allows the defined shapes 16 or 22 to be individually any
shape, such as
the defined shape 16 for the support frame portion 14 being smaller or larger
than the defined
shape 22 of the tensioning frame portion 20, the same shape (mirror image of
one another), or
completely different from one another. Therefore the chair back 10 has
limitless possibilities
of designs or shapes. Finally the removable elastomeric support sleeve 24 may
be an
CA 02470488 2004-06-07
elastomeric mesh that provides support. Furthermore a removable lumbar support
or pillow
50 (Figure 2) may be inserted though the opening 26 and positioned
accordingly.
The method of assembling the chair back 10 is provided. First the bottom
region 48
of the removable elastomeric support sleeve 24 may be slid first over the
support frame
portion 14 so as to conform the removable elastomeric support sleeve 24 to the
defined shape
16 of the support frame portion 14. More specifically the support member 30
may be slid
through the opening 26 on the back side 44 of the elastomeric support sleeve
24. The
tensioning frame portion 20 may then be slid into the top region 46 of the
removable
elastomeric support sleeve 24 thereby conforming the elastomeric support
sleeve 24 to the
defined shape 22 of the tensioning frame 20. The first and second ends 38 and
40, of the
tensioning frame 20 may then be inserted into the openings 32 of the support
frame portion
14. The force or pressure of connecting the tensioning frame portion 20 to the
support frame
portion 14 locks the defined shape 16 of the support frame portion 14 and the
defined shape
22 of the tensioning frame portion 20 to one another. Furthermore the
removable elastomeric
support sleeve 24 is automatically tensioned both vertically and horizontally
across both the
tensioning frame portion 20 and the support frame portion 14, thereby forming
the chair back
10.
The assembled chair back 10 does not require any fasteners or mechanical
attachments to keep the removable elastomeric support sleeve 24 in place.
Therefore there is
no need for upholstery type trim or covering to hide traditional fasteners
that are usually
required to hold the fabric or upholstery in place. Furthermore the pressure
or force to Iock
the tensioning frame portion 20 and the support frame portion 14 together
keeps the chair
back 10 from disassembling and keeps the removable elastomeric support sleeve
24 in place.
Finally the chair back 10 configuration allows for easy instalment and
assembly in the field.
Other variations and modifications of the invention are possible. All such
modifications or variations are believed to be within the sphere and scope of
the invention as
defined by the claims appended hereto.
