Disposable chair

Lightweight chair from a single unitary die-cut and scored generally rectangular blank of sheet material which is collapsible for easy storing and carrying, and which pops open for easy set-up. The lower 10-20% of the blank has a plurality of flaps gulable to the inner face of adjoining sidewall panels to form a reinforced base perimeter. Half of the blank forms the chair base sidewalls, and the remaining upper half forms a pair of adjoining seat/back panels which are delineated from the sidewalls by a set of generally W-shaped score lines. An assembly tab at one end is fastened to the opposite side of the other end of the blank to form in cross-section an enclosed polygon, preferably a modified hexagon of unequal sides. A first of the pair of seat/back panel assemblies is folded down with one or more tabs or flaps frictionally engaging one or more of the sidewall panels. Then the second of the pair of seat/back panel assemblies is folded over the first, and an interlocking tab engages a slot in the first to complete the assembly. In use the seat is oriented with one of the polygon (hexagon) corners forward to provide leg room on either side. A generally triangular or trapezoidal backrest panel is joined to a generally rectangular middle seat panel, and the seat portion in joined in turn to a generally triangular legrest panel.

FIELD OF THE INVENTION 
This invention relates to an article of furniture, and more particularly to 
a lightweight chair made from sheet material which is collapsible for easy 
storing and carrying, yet which is simple to manufacture and set up and 
sufficiently inexpensive to be disposable, preferably in a manner in which 
its materials can be recycled, and which is assembled from a single 
die-cut and scored blank. 
BACKGROUND OF THE INVENTION 
There have been many attempts in the prior art to fabricate lightweight 
chairs and other furniture items from corrugated cardboard. While such 
cardboard materials have a relatively brief useful lifespan because they 
are not inherently highly durable, the low cost of the materials and 
methods of manufacture have resulted in relatively inexpensive chairs, 
thus justifying the relatively short useful lifespan. 
Exemplary of the art in this field are the following patents: Steuer U.S. 
Pat. No. 3,149,880; Snyder U.S. Pat. No. 3,178,227; Downes U.S. Pat. No. 
3,220,362; Giebel U.S. Pat. No. 3,463,546; Caigan U.S. Pat. No. 3,604,751; 
and Klein U.S. Pat. No. 4,085,970. To our knowledge, none of these has met 
with general acceptance or marketing success which we believe may be due 
to the relative complexity of these chairs in terms of the blank layout 
and material wastage, the difficulty of "set-up" or assembly of the chairs 
by the consumer at the time of use, the difficulty in disassembly for 
storage (they are not easy to knock down for storage), and relatively poor 
seating comfort. While complex or multi-part blanks are difficult to set 
up and knock down for storage or shipping, they also very significantly 
increase the cost, thus making them unattractive to the consumer in view 
of their very short lifespan. 
To our knowledge, there is no single-use, lightweight, portable chair which 
is fabricated from a single, standard-size sheet of relatively rigid 
material to form a chair that is inexpensive, simple to manufacture, can 
be easily set up and knocked down, is easy to carry, and is ergonomically 
comfortable. 
Accordingly, there is a need in the art to provide such type of chair which 
is economic even from a single-use point of view for outdoor festivals, 
special events, or any other situation in which large crowds gather for a 
relatively short period of time where there is no immediate seating 
readily available. Such use extends to campgrounds, parks, garden parties, 
barbecues, picnics, beach usage, and the like, where it is desirable to 
provide inexpensive seating for limited use and which may be conveniently 
disposed-of when desired, or knocked down to flat form for transport and 
storage. Another important use is for children's furniture as children, 
during growth years, need various sizes of furniture before being able to 
be comfortable in adult-sized furniture. In addition, this type of 
furniture would be useful in children's playrooms or parties as it will 
save wear and soiling of other household furniture. 
THE INVENTION 
Objects 
It is among the objects of this invention to provide a chair fabricated 
from a single, standard-sized sheet of a lightweight, high-strength, 
relatively rigid material in sheet form such as cardboard, fiberboard or 
plastic. 
It is another object of this invention to provide an improved disposable 
chair which is formed from a one-piece die-cut and prescored blank in 
which all the chair elements are integrally connected. 
It is another object of this invention to provide a preassembled chair unit 
which can be folded flat either for shipping or storage, and which pops 
open for easy set-up of the chair for use. 
It is another object of this invention to provide a preassembled chair unit 
which can be set up in a few, very simple and quickly performed manual 
steps without the use of any tools. 
It is another object of this invention to provide a blank and resulting 
preassembled chair unit of a lightweight, high-strength, relatively rigid 
sheet material which can be produced in various sizes ranging from 
children's size to adult size. 
It is still another object of this invention to provide a preassembled 
disposable chair which has a handhold specially disposed therein for ease 
of carrying. 
It is another object of this invention to provide a preassembled, pop-open 
chair unit which is ergonomically designed to provide optimum comfort and 
lumbar (lower back) support for continuous seating over an extended period 
of time yet is able to safely accommodate a variety of human sizes and 
weights. 
It is another object of this invention to provide a blank for a disposable 
chair, and the preassembled chair unit made from said blank, which can be 
coated with a variety of coatings such as waterproofing or graphics to 
render the chair resistant to moisture damage and allowing for extensive 
areas on the chair for advertising or promotional purposes. 
It is another object of this invention to provide a blank for a disposable 
chair which is simple to manufacture, preassemble and use, yet which is 
sufficiently cheap that the chair may be sold for one-time usage for 
promotional purposes. 
It is still another object of the invention to provide a means for 
retaining a trash bag in association with a disposable chair so that users 
may conveniently dispose of trash in the chair while at use at concerts, 
picnics and the like, and which can then be easily disposed of either 
separately or along with the chair at the end of the event. 
Still further and other objects of this invention will be evident from the 
description and drawings. 
SUMMARY 
A one-piece blank is die cut from a standard width (for an adult chair) of 
corrugated cardboard. The blank is generally rectangular with panels 
defined therein by joined score lines. The lower 10-20% of the blank is 
separated by parallel cut-out slots into a plurality of optional flaps or 
base panels which are later folded 180.degree. to be glued to the inner 
face of adjacent sidewall panels to form a reinforced base perimeter. 
Approximately half of the vertical balance of the blank forms the 
sidewalls, and the upper half forms a pair of interconnected seat/back 
panels. The seat/back panels are delineated from the sidewalls by a 
generally W-shaped set of score lines. Generally trapezoidal sidewall 
panels are defined between the W score lines and the optional reinforcing 
base panels. 
The blank has a tab at one transverse end which is fastened to the opposite 
side of the other end of the blank to form in cross-section an enclosed 
polygon, preferably a modified hexagon of unequal sides. A first of the 
pair of seat/back panel assemblies is folded down with one or more tabs or 
flaps frictionally engaging one or more of the sidewall panels. Then the 
second of the pair of seat/back panel assemblies is folded over the first, 
and an interlocking tab engages a slot in the first to complete the 
assembly. 
In use the seat is oriented with one of the polygon (hexagon) corners 
forward to provide leg room on either side. A generally triangular or 
trapezoidal backrest panel is joined to a generally rectangular middle 
seat panel, and the seat portion is joined in turn to a generally 
triangular leg panel. The seat/back assembly is ergonomically designed for 
optimum comfort and lumbar (lower back) support for continuous seating 
over an extended period of time by having the panels oriented so the leg 
support is tilted upward from the horizontal, the adjoining middle seat 
panel is tilted downwardly from the horizontal, and the back panel is 
inclined backwardly from the vertical, (preferably less than 35.degree.). 
The combination of the seat/back panels forms in cross-section a 
multi-planar C-shape concave up and tilted with its imaginary central axis 
at an acute angle forward from the vertical. 
Once the end tab is glued to the other end to form the enclosed polygon, 
the assembly can be folded flat for storage or shipping. A pair of aligned 
apertures functioning as handholds are placed medially of the upper and 
lower edges of the blank, preferably in the middle seat panel toward one 
end thereof. By placing the handhold toward the middle of the blank, the 
chair blank can be carried without one end (or side) dragging on the 
ground. Further, the blank will be carried more securely in windy 
conditions as approximately half of the blank will be secured between an 
arm and the carrier's body, and the lower half can be pressed against the 
user's leg. 
The backrest panel is preferably a truncated triangle (trapezoid) so that a 
generally triangular aperture is formed between it and the rear sidewalls. 
This provides a space through which a stake can be driven to keep the 
chair from being blown away by the wind when unoccupied. The stake may be 
a bare stake, a light pole of some sort, an umbrella pole for sun, shade 
or rain protection, or the like. Likewise, a refuse bag can be suspended 
in the hole to provide a handy place for disposal of paper, plastic, cans 
or glass refuse of the type common at picnics, concerts, beaches, and the 
like. 
The chair is lightweight, easy to carry, stores flat and pops open for easy 
assembly. The solid sidewalls forming the base of the chair provide 
extensive area for graphics of a promotional or design nature. The sheet 
material can be any lightweight, high-strength, relatively rigid material 
such as corrugated cardboard, fiberboard, plastic, light wood (with cloth, 
plastic or paper webbing to join the panels), and the like. We prefer 
350-450 lb test dual arch corrugated cardboard, which may be plasticized 
(curtain coated) to make it moisture resistant for longer life. The piece 
blanks can be cheaply and rapidly produced on continuous rotary die-cut 
presses, for example, a 5' Maramatsu press taking standard 3'.times.5' 
sheets. The wastage for the blank shown in FIG. 1 is under about 10%, and 
the blank may be oriented with its longitudinal axis either parallel or 
transverse to the long axis of the cardboard sheet, depending on the chair 
size desired. The blank shown may be scaled in size for children to adult 
sizes, and lighter weight cardboard may be used for children's sizes, if 
desired. Neither set-up nor take-down of the chairs requires tools. The 
chair is so cheap to make that it can be disposed-of after a single use. 
Because of its nature, the chair sheet material is ideally suited to be 
made from recycled material, and again recycled after use. Likewise, the 
used chair, as garbage, could be used for fuel. 
Because of the overlapping seat/back assemblage of panels and the hexagonal 
ergonomic design, the chair structure does not break in extensive normal 
use. For example, when weight is placed in the center of the seat (on the 
middle seat panels), the sidewalls are drawn together, rigidifying the 
structure. On overuse, the chair will gradually collapse, which is a 
safety feature. In large crowds, such as at rock concerts, some 
participants become unruly. Because of the cardboard nature of the 
materials, the chair cannot be used as a deadly weapon.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The following detailed description of the preferred embodiments is by way 
of illustration and not by way of limitation of the general principles of 
this invention. 
Referring now to the drawings, FIG. 1 shows a one-piece blank 1 of the 
chair of this invention die cut from a sheet of dual arch corrugated 400 
lb test cardboard. The side shown facing the viewer in FIG. 1 becomes the 
exterior of the chair when assembled. As noted, the blank is generally 
rectangular as defined between top margin 2, 2', bottom margin 3, rear 
margin 4 (on the left side of FIG. 1), and assembly flap margin 5 (on the 
right side of FIG. 1). As noted, these margins have various cut-outs 
(removed portions) to define the perimeters of various panels as described 
in more detail below. As seen best in FIG. 1, the assembly flap M is 
secured to the reverse side of panel D in the area outlined by the dashed 
line adjacent to the rear margin 4. The assembly flap M may be fastened by 
glue, staples or other means to the panel D. When so assembled, the chair 
is then in its knocked-down or pre-setup condition, and the handle 
apertures S and S' in panels N and Q are aligned for carrying. This is 
best seen in FIGS. 2A and 2B. This is the shape of the chair for shipping, 
carrying or storage. 
The only other panels or flaps which are glued or otherwise secured in the 
assembly are optional base panels A, B, C and their corresponding base 
panels A', B' and C'. These are folded 180.degree. and glued or otherwise 
secured to the inside face of adjoining vertical wall panels D, E, F, D', 
E', F', respectively, to form a reinforced base for the chair. All of 
these reinforcing panels A, B, C, A', B', C' panels G, H, and I are 
optional and may be omitted although we prefer to have them to produce a 
stronger, more reinforced product. 
It will also be noted that there is only one locking tab in the preferred 
embodiment. This is tab Z' formed along the upper margin 2' extending from 
the edge of backrest panel R. This is inserted into slot Z in the inner 
backrest panel K as best seen by comparing FIGS. 8, 9 and 10. 
Returning to FIG. 1, the right side of the chair comprises the assemblage 
of panels which are identified by A-F and K, N and O (which in the drawing 
lie on the left). The panels forming the left side of the chair are 
identified in FIG. 1 for the most part with primes A'-F' (except for 
individual letter designations for the seat/back assembly overlay panels 
P, Q and R), and these lie on the right of FIG. 1. The right side and left 
side of the chair assembly are joined by a front rib or webbing AA of 
generally rectangular configuration which joins the adjacent front right 
panel F to the front left panel F' along their common boundary. The width 
of the front rib or web AA needs only be wide enough to provide a bend in 
the cardboard to compensate for the multi-layer thickness in the folded 
condition as best seen in FIG. 2C, and so that the scoring between the 
front right and front left panels F and F', respectively, is not so sharp 
that a tear develops along that juncture under usage or handling 
conditions. Likewise, there is a rear rib or web BB joining the assembly 
flap M to the left rear sidewall panel D' which serves the same function. 
The front and rear rib panels or webs AA and BB are also seen in FIGS. 3, 
4, 5, 9 and 10. 
Inset upwardly from the bottom margin 3 are a pair of double score lines 6, 
6' which are generally parallel to the bottom margin 3. As seen, there are 
a series of relieved portions or cut-outs (30, 31, 32, 33, 34), which 
serve to define the side margins of the bottom reinforcing panels A, B, C, 
A', B' and C'. These bottom panels are folded 180.degree. upwardly to be 
secured to the inner face of the corresponding panels to which they are 
attached, panels D, E, F, D', E' and F'. As seen in FIG. 1, this involves 
folding "downwardly" (through the plane of the figure paper) so that the 
hidden face of the panels A-C' are secured to the hidden face of the 
panels D-F'. This is shown by the arrows CC on the right and left side of 
FIG. 1. FIGS. 2A, 2B, 2C, 4, 5 and 8 show these base reinforcing panels 
glued in position along the lower margins of the sidewall panels D-F and 
D'-F' in dashed lines because they are hidden from the exterior view. 
FIGS. 6 and 7, being section views, show the panels A-C, A'-C' and M glued 
in position from an interior view. As noted above, these base panels A-C 
and A'-C' are optional but are preferred when using untreated corrugated 
cardboard to make a stronger product. Where it is desired to have a taller 
chair, the vertical height of these base panels A-C and A'-C' can be 
reduced. Indeed, the sidewalls D-F and D'-F' can be extended the entire 
width of the panels A-C and A'-C' if desired where the material strength 
permits for the particular lifespan projected for the chair. 
The balance of the blank shown in FIG. 1 lying between the double score 
line 6, 6' and the top margin 2, 2' is roughly divided in half with the 
lower portion defining the two sets of right sidewall panels D-F and left 
sidewall panels D'-F'. There is a continuous but jointed set of score 
(fold) lines roughly in the shape of a W, which form left to right are 
score lines V, W, X, X', W' and V'. These divide the upper seat/back panel 
assemblies from the lower sidewall panel assemblies. Note that the 
sidewall panels are generally trapezoidal. The vertical rear right 
sidewall panel D is defined between margin 4 and score lines V, 7 and 6'. 
Center right sidewall panel E is defined between score lines 7, W, 8 and 
6'. Front right sidewall panel F is defined between score lines 8, X, 
front rib AA, and 6'. The rear left vertical sidewall panel D' is defined 
between score lines 10, V', rear rib panel BB, and double score line 6'. 
Center left vertical sidewall panel E' is defined between score lines 9, 
W', 10 and 6'. Front level vertical sidewall panel F' is defined between 
the front rib AA and score lines X', 9 and 6'. 
Note that in the upper portion of the rear right side vertical sidewall 
panel D and the corresponding panel D' are defined triangular panels J and 
L, respectively, between score lines U, 11 and V (for panel J) and U', 11' 
and V' (for panel L). These panels J and L are called backrest support 
panels, J being for the right side and L being for the left side, and have 
the function of providing lost motion in movement and flexing of the 
seat/back panel assemblies as described in more detail below. Also, as 
noted above, flaps G and I are reinforcing flaps or panels to reinforce 
the backrest support panels J and L, respectively. They are defined 
between the double score lines 11 and 11' and the margin edges of the 
panel, respectively. 
Double score lines are used when the panel is to be folded over 180.degree. 
back onto the adjacent panel and secured thereto. Where the panel or flap 
is folded less than 180.degree., a single score line is used. 
The optional panels G and I are preferably glued to the inside face of 
panels J and L, respectively. The notched margin Y' of panel I interlocks 
with the notched margin Y in panel K as described in more detail below. 
Likewise, a triangular flap H is defined from panel K by double score line 
12 and the marginal edges. Panels G and H are separated from each other by 
relieved slot or cut 13. Panel H is infolded and secured to the inside of 
panel K as an optional reinforcing panel. A preferred securing method is 
use of glue. Panels J, K and L may be extended into panels G, H and I, 
respectively, to raise the height of the back support by moving the score 
lines 11, 12 and 11' toward the apex of the panels G, H and I. 
The upper portion of the blank 1 comprises a pair of three seat/back panel 
assemblies, the underneath seat/back (lower) assembly comprising panels K, 
N and O being joined to the right side vertical sidewall panels DEF along 
score lines V, W and X. Likewise, the seat/back overlay (upper) panel 
assembly comprising panels P, Q and R are joined to the left vertical 
sidewall panel assembly D', E' and F' along the score lines X', W' and V'. 
The lower legrest panel O and upper legrest panel P are generally 
triangular, and are joined along fold lines 14, 14' with seat panels N and 
Q, respectively. Seat panels N and Q are generally rectangular and have 
disposed adjacent score lines W and W' "stadium"-shaped apertures S and 
S' which function as handholds. The apertures S and S' are so disposed 
that they are in alignment when the assembly flap M is glued to the inside 
of panel D as shown in FIGS. 2A and 2B. The apertures S and S' may be 
disposed in the legrest panels O and P as seen in FIG. 1. 
Adjacent the other marginal edge of panel N along fold line 15 is a 
triangular panel T which serves as a frictional interlock against the 
upper portion of the inside of panel E' when the chair is in its set-up 
position. This is best seen in FIGS. 4, 6 and 8. No glue is used on this 
panel unless the chair is desired to be set up permanently, that is, so it 
cannot be knocked-down and folded flat. If a permanent installation is 
desired, then glue may be applied to the face of flap T showing in FIG. 1. 
When assembled, the score line 15 abuts the score line W' on the inside 
face of panel E'. 
The lower (underneath) backrest panel K is trapezoidal and is defined 
between score lines 16, V, 12 and 2. Likewise, the corresponding upper 
(overlay) backrest panel R is defined between score lines 16', V', margin 
12' and margin 2'. As described above, locking tab of flap Z' is defined 
as an extension of panel R along margin 2'. 
The upper portions of FIGS. 2A and 2B show how panels G, H and I are folded 
over and glued to the inside faces of panels J, K and L, respectively. 
These folded over and glued panels are also identified in FIGS. 3-7, 8 and 
10. Note particularly in FIG. 10 how the notched margin Y in panel K 
interlocks with the notched margin Y' of panel I. This provides excellent 
locking support for the back. The marginal edge of panels O and P are 
identified with the numerals 17 and 17', respectively (FIGS. 1 and 10). 
By following through on FIGS. 3-7, the various score and panel numbers and 
letters, the working relationship of the various panels to each other can 
be seen. Note particularly in FIGS. 3, 5, 6, 7 and 10 that the score lines 
11, 11' and 12 form a triangular opening into which a garbage bag 19 
and/or a stake or umbrella 20 can be inserted. The stake 20 can be the 
support pole of an umbrella (be it for rain or sun shade), a light pole or 
the like. Alternatively, panel H is not secured to panel K and an oval 
hole 27 (FIG. 1) provided therein to receive the stake 20 so that the 
chair is secured against movement. 
Looking now in particular at FIGS. 2A, 2B, 2C, 8, 9 and 10, the following 
steps are employed to set up the chair. First, the unit shown in FIGS. 
2A-2C is popped open by pulling apart the two sides of the unit at the 
handle openings S and S' to form a three-dimensional base, the sidewalls 
in horizontal section view forming a modified hexagon with one acute angle 
facing forward, that being the angle formed between the vertical front 
right and left sidewall panels F and F'. As best seen in FIGS. 8 and 9, 
the front apex is the front rib panel or web AA joining the sidewall 
panels F and F'. The lower seat portion formed by the three panels K, N 
and O are then folded down along the score lines V, W and X as indicated 
in FIG. 8. The flap T is folded down along score line 15 so that its outer 
surface contacts the inner surface of panel E'. In the process of folding 
down, the panel J will flex outwardly along the score line U away from the 
rear right side vertical sidewall panel to permit lost motion in the 
folding. One or more of the upper seat/back assembly panels P, Q and R may 
also flex during this step. The notches Y along the marginal edge 2 of 
panel K will then engage the notches Y' in panel I which has been secured 
to the inner face of panel L. Then the upper seat/back panel assembly, 
panels R, Q and P, are folded down over the lower seat/back panel assembly 
(panels K, N and O), and the tab Z' is secured into the slot Z. In this 
step, the panel L will likewise flex along score line U' to permit lost 
motion in the folding. FIG. 9 shows the completed folding of the upper 
seat panel assembly, panels R, Q and P. 
As best seen in FIG. 10, the tab Z' is then firmly locked in the slot Z in 
the lower seat/back assembly panel K. The panels J and L have returned to 
a position coplanar with the rear right and left vertical sidewall panels 
D and D', respectively. Note the notch 24 in tab Z' faces downwardly; when 
the user sits in the chair, his or her weight forces the panels Q and R 
downwardly engaging the end 25 of slot Z in the notch, positively locking 
panel R against panel K. 
In use, when the user sits on the chair putting weight on the seat panel Q, 
the flex panels J and L actually flex inward, and the notches Y and Y' are 
more firmly interlocked. 
To knock the chair down for storage or transport, the tab Z' is slipped 
upwardly and out of the slot Z, the upper seat/back panel assembly is 
raised, the lower seat back assembly is then lifted to a vertical 
position, and the two sides brought together so the assembly is again in a 
flat configuration as shown in FIGS. 2A through 2C. 
If a permanent installation is desired, the face of tab T (as seen in FIG. 
1) may be glued or otherwise fastened to the inside of panel E'. Likewise, 
the tab Z' can be glued to the inner face of panel J. Double-sided tape or 
Velcro fastening strips may be employed. 
It is also possible to provide an interlock of tab T (or a modification of 
tab T) in the sidewalls of panel E' by providing a slot in panel E'. 
Likewise, tab T could be interlocked into panel Q by providing a slot 
therein, if desired. However, we have found that this is not necessary for 
occasional or short-term use of the disposable chair of this invention. We 
have found that in operation, the weight placed on the chair back panel R 
tends to urge the lower panel N to the left (as seen in FIG. 10; to the 
right in FIG. 9), thus urging the face of tab T against the inside of the 
vertical sidewall E'. This provides a sufficient frictional interlock. 
Likewise, panels E and E' can be vertically shortened by the extension of 
slots 30, 31, 33 and 34 (defining the side margins of panels B and B') so 
that upon folding upward, a folded-over edge of the bottom of panels B and 
B' (the folded-over edge being identified in FIG. 1 as formed by fold line 
21, 21') provides an additional vertical support for the side edges of 
panel N along score lines W and 15. In this embodiment, the flap T may be 
omitted. In this embodiment, as best seen in FIG. 10, panel E would only 
extend downwardly as fas as line 22 unless there was an extension of 
panels B and B' lower than the edge of the blank 3 as shown in FIG. 1. 
FIG. 11 shows an enlarged view of an alternate embodiment of locking tab Z' 
which is inset along margin 21 of panel R. The corresponding slot Z would 
be moved inwardly in panel K away from the score line V. In this 
embodiment panels R and K may be widened rather than tab Z' being inset, 
and wastage is reduced. If the seat/back panels are widened, then all 
panels D-F and D'-F' must be widened proportionately. 
Various other modifications and additions to the chair of this invention 
may be made. While it is seen that the angles from the vertical of the 
various panels which form the seat/back assembly (panels K, N, O, R, Q and 
P) are ergonomically designed to provide a most comfortable seating 
arrangement with excellent lumbar support, it can be appreciated that the 
angles may be varied somewhat depending on the intended use. For example, 
the backrest panels R and K may be inclined further back for a beach-type 
chair to provide more sun exposure. Likewise, the width of panels E, E', N 
and Q can be changed or eliminated entirely as desired. When the panels E 
and E' are either eliminated or reduced to a small webbing analogous to 
the webbing AA or BB, then the seat panels N and Q are likewise reduced, 
and the leg panels O and P are enlarged. In these cases, the tab T may be 
eliminated, and the larger tab 22 as shown best in FIG. 1 may be employed. 
In addition, it should be understood that the flap 26 may be employed in 
the configuration of the chair as shown in FIGS. 1-10. This would provide 
additional support for the leg panel P. From the ergonomic viewpoint, for 
greatest seating comfort we prefer keeping substantially seat panels N and 
Q, having the backrest panels K and R oriented at no more than 35.degree. 
back from the vertical, and the legrest panels O and P at no less than 
5.degree. up from the horizontal. As shown in phantom in FIGS. 9 and 10, a 
locking tab Z' may be formed adjacent the margin of upper seat panel Q 
and/or legrest panel P which interlocks in corresponding slot Z in lower 
seat panel N and/or legrest panel O. 
It should be understood that various modifications within the scope of this 
invention can be made by one or ordinary skill in the art without 
departing from the spirit thereof. For example, just as panels B and B' 
can be extended so that upon folding 180.degree. to be secured to the 
inside of panels E and E', respectively, so panels A, A' and/or C, C' can 
be extended to meet fold lines U, U' or X, X', respectively, to provide 
added support to the legrest and/or backrest panels. We therefore wish our 
invention to be defined by the scope of the appended claims as broadly as 
the prior art will permit, and in view of this specification if need be.