Note: Descriptions are shown in the official language in which they were submitted.
5~
BAC~GROUND OY TH~ INVENTION
FIELD OF THE INVENTION
This invention relates to chairs of the type
comprising a tubular frame supporting seat and back
panels; in some cases, these panels are combined to form
a single seat/back.
Chairs of the general type referred to above
can be designed for a variety of uses, for example as
patio furniture or office furniture. However, a primary
market for this type of chair is in the institutional
field; that is, in schools, recreation centres and the
like. Chairs for sale to this market will typically be
designed so that they can be ganged together in rows to
provide multiple seating at appropriate times, and also
stored in stacks when not in use.
It has been recognized that a stacking chair
should preferably be designed with no bracing cross
members or "stretchers" between the legs at opposite
sides of the chair. This is because the presence of such
cross members can make the chairs difficult to stack and
also precludes use of the space below the seat for stor-
age. Preferably, a stacking chair should be designed so
that stacking can be accomplished primarily by lifting
the chair only a short distance and then moving the chair
rearwardly onto the stack; in other words, the stacking
motion should primarily involve horizontal movement of
~'
- 2
the chair and should avoid the need to lift the chair
through a substantial vertical height such as may be
required when the chair design dictates that the chair
being stacked must be lifted high enough to completely
clear the seat of the chair below before stacking can be
accomplished. However, it is difficult to design a chair
without cross members while at the same time achieving
the structural rigidity and robustness required in the
institutional seating seating field.
An object of the present invention is to
provide a chair which can be built to meet these design
criteria.
SUMMARY OF THE INVENTION
The chair provided by the invention has a seat
panel, a back panel, and a unitary frame supporting the
panels. The frame is shaped to define a pair of closed
loops at opposite sides of the chairr each including a
pair of generally upright limbs forming front and rear
legs, and top and bottom limbs extending between upper
and lower ends of the respective upright limbs. The
limbs forming the rear legs of the respective loops have
portions which extend upwardly above the top limbs and to
which the back panel is secured. The frame further
includes a first cross member joining the upwardly exten-
ding portions of the rear leg limbs and a second crossmember coupling the top limbs. The seat panel is suppor-
ted on and secured to the top limbs of the respective
.
-- 3 --
loops and serves as a structural member maintaining the
required spacing of the loops.
It has been found that a chair having these
features can be designed with significant structural
rigidity and robustness without the need for cross
bracing between the loops which form the legs of the
chair. The fact that the seat acts as a structural
member contributes significantly to the overall rigidity
of the chair.
The two cross members also aid in achieving
these objectives. Preferably, both of the cross members
are disposed in the back area of the chair and are over-
laid by the back panel.
The chair provided by the invention may be ~but
is not necessarily) designed as a stacking chair. As
will be explained in more detail, the design can be such
that stacking is achieved primarily by front-to-back
movement of the chair.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly
understood, reference will now be made to the accompany-
ing drawings which illustrate a preferred embodiment of
the invention by way of example, and in which:
Fig. 1 is an exploded perspective view of a
chair in accordance with this embodiment of the inven-
tion;
Fig. 2 is a view similar to Fig. 1 showing the
4 _
chair assembled ~nd fitted with an optional table~ arm;
Fig. 3 is an underneath perspective view from
the rear~ corresponding to Fig. 2;
Figs. 4, 5, 6 and 7 are sectional views on
lines 4-4, 5-5, 6-6 and, 7-7 of Fig. 3;
Fig. 8 is a sectional view on line 8-8 of Fig.
2;
Fig. 9 is a perspective view somewhat similar
to Fig. 2 but showing two chairs stacked together;
Fig. 10 is a sectional view on line 10-10 of
Fig. 2; and,
Fig. 11 is an underneath perspective view
corresponding to Fig~ 10.
DESCRIPTION OF T~E PREFERRED EMBODIMENTS
Referring first to Fig. 1, the chair is shown
to comprise a seat panel 20, a back panel 22 and a
unitary tubular frame 24. In the iIlustrated embodiment,
the chair also includes arms 26 and 28 but these are
optional and one or both arms may be omitted particularly
where the chairs are intended to be ganged together to
form multiple seating. In that event, it might be
appropriate to provide arms, say, only at opposite ends
o~ a row of seating or/and to provide only one arm be-
tween each pair of chairs. In any event, the a~ms are
secured to the frame by screws as will be described and
may be omitted or included as required.
Frame 24 is made from a single length of
circular section steel tubing bent to the conf iguration
shown with the ends of the length of tubing butt welded
together as at 30. The rame defines a pair of closed
loops 32, 34 at opposite sides of the chair, each inclu-
ding a pair of generally upright limbs forming front andrear legs and top and bottom limbs ex~ending between
upper and lower ends of the respective upright limbs. In
the illustrated embodiment, the limbs of loop forming the
front and rear legs are denoted 36 and 38 respectively
and the top and bottom limbs are denoted 40 and 42
respectively. The corresponding limbs of loop 34 are
denoted 44, 46, 48 and 50.
The limbs 38 and 46 forming the rear legs of
the respective loops have upper portions 38a and 46a
respectively which extend upwardly above the top limbs 40
and 48 and to which the back panel 22 is secured as will
be described. The frame also includes a first cross
member 52 joining the upwaraly extending limb portions
38a and 46a; in this particular embodiment, cross member
52 is formed by inwardly deflected extensions of those
limb portions and forms a top rail at the back of the
chair. The frame also includes a second cross member 5~
which couples the top limbs 40, 48 of the respective
loops 32, 34. In this embodiment, cross member 54 is
positioned somewhat above those limbs so as to be dis-
posed behind the back panel 22 in the assembled chair.
Cross member 54 is coupled to the top limbs 40, 48 by way
~t,~ 3
-- 6 --
of intermediate frame portions 56, 58 respectively which
extend upwardly from those limbs inwardly of the leg
extensions 38a, 46a. It will be seen that each of the
intermediate portions 56, 58 is shaped, as seen from the
side, to incline upwardly from the respective loop top
limb and to then run parallel with a part of the relevant
rear leg extension before curving inwardly to form the
cross member 54.
In Fig. 1, these parallel portions of the frame
are generally denoted 60 and 62 and the frame portions
are joined together at this location through aligned
holes indicated respectively at 64 and 66. This is
accomplished by bolts which are also used to secure the
back panel in position as will be described later. By
securing the frame portions together at these locations,
the respective loops 32 and 34 of the frame are "closed",
effectively prevently relative movement between the limbs
of the loop and rendering the loop substantially rigid.
Seat panel 20 is supported on and secured to
the top limbs ~0, 48 of the respective loops and serves
as a structural member maintaining the required spacing
of the loops. Details of the construction of seat panel
20 and the manner in which it is secured to frame 24 will
be described later.
In Fig. 2, both seat panel 20 and back panel 22
are shown secured in position on the frame. Back panel
20 is made of sheet steel and has side and top marginal
~L~ 3
-- 7
portions which are rolled to fit snugly around the por-
tions of frame 24 at the sides and top of the back. By
way of illustration, reference numeral 68 has been used
in Fig. 8 to denote the sheet steel from which panel 22
is made and a side marginal portion of the sheet is shown
at 68a rolled around part of the rear leg extension 46a.
That view also shows a bolt 70 which extends through
panel 68, through diametrally aligned holes in extension
46a and into an opening in the intermediate frame portion
1058 at location 66 in Fig. 1. Bolt 70 is then screwed
into a captive nut 72 inside that portion of the frame.
In this way, a single bolt not only holds part of the
back panel 68 in position but also secures together the
two parallel frame portions at location ~2.
15The head of bolt 70 is visible at 70a in Fig.
2. A rivet 74 is used to secure the back panel to the
frame at a location above bolt 70 so that the panel is
secured to the frame at two points. Similar fastenings
are provided at the oppsite side of the back panel, which
is not visible at Fig. 2. The upper marginal edye of the
back panel is merely rolled over the cross member 52 as
best seen in Fig. 3 but is not secured to that cross
member. Panel 22 is shaped to define "cut-outs" 76, 78
at opposite ends of that rolled over top marginal
portion. These cut-outs are shaped to provide hand grips
at which the frame can be grasped for lifting and other-
wise manipulating the chair.
~ 8 --
In addition, back panel 22 is provided with a
rectangular opening 80 generally centrally of its width
and somewhat above its lower edge, which opening also
provides a hand grip. The location of opening 80 is
selected in conjunction with the location of cross
member 54 so that the opening is disposed immediately
below the cross member. In addition, and as best shown
in Fig. 6, portions of the sheet of steel 68 from which
~he back panel is made are curved inwardly as indicated
at 80a, so that the opening presents a smooth edge to the
hand of a person attempting to lift the chair. Fig. 6
clearly shows the location of cross member 54 immediately
above the opening; this allows the chair can be lifted by
directly grasping that cross member so that the lifting
force is directly imposed on the frame of the chair.
As best shown in Figs. 3 and 4, seat panel 20
comprises a peripheral frame 82 and a sheet steel member
84 which is tack-welded to the frame. Frame 82 is also
made of circular section tubular steel although of
slightly smaller diameter than the main frame 24 of the
chair. The ~ube is formed into a closed loop dimensioned
to fit exactly between the top loop members 40, 48 of the
chair frame. As best seen in Fig. 1, the sheet steel
member 84 includes portions 84a at both sides which
overhang frame 82 and which are shaped to form downwardly
directed angles dimensioned to snugly embrace the top
limbs 40, 48 of the chair frame. Except at the locations
':
~2~ 3
of the these overhanging portions, the marginal areas of
sheet 84 are rolled over frame 82 to present a smooth
peripheral edge on the seat. In the assembled chair, the
angled portions 84a embrace the respective top limbs 40,
48 of frame loops 32, 34 and are bolted to those limbs as
illustrated in Fig. 4O That view shows one of four bolts
used to secure the seat panel in position (two at each
side) and it will be seen that the arrangement is gener-
ally similar to that shown in Fig. 8. Thus, a bolt 86
extends through the outer limb of angle 84a, through
holes in limb 48 of the chair frame and into a hole in
the seat frame 82. A captive .llt 88 in seat frame 82
receives bolt 86. In this way, the seat panel is secure-
ly bolted to the frame 24 at four locations and forms an
integral structural part of the chair.
Fig. 4 also illustrates the manner in which the
arms 26, 28 are secured to frame 24. Referring to arm 28
by way of example, it will be seen that the arm is made
from a tubular steel member which is formed into a
C-shape having top and bottom limbs 90 and 92 respective-
ly and a base 94 (Fig. 1). Along the bottom limb g2 and
part of the base 94, the tube is indented to the cross-
sectional shape shown in Fig. 4 in which the indended
face 92a of limb 92 snugly fits the external profile of
the main frame limb 48a. Two screws, one of which is
shown at 98 in F ig . 4 then extend upwardly through limb
92 and into limb 48 to secure the arm to the main frame.
- 10 -
A plastic collar 100 is provided behind the head of screw
98.
~ s noted previously, a chair in accordance with
the invention can be designed to stack with other similar
chairs and the chair shown in the drawings is in fact
designed in this way. Thus, the main frame loops 32 and
34 are disposed in respective planes which are angled
outwardly slightly towards the bottom of the chair and
the arms 26, 28 are oppositely angled outwardly. These
features, coupled with the generally C-configuration of
the arms 26, 28 provides the required stacking facility.
The arm configuration allows stacking to take place
primarily from the front without the need to lift the
chair being added to or removed from the stack to an
excessive height. Fig. 3 best illustrates the manner in
which the arms are angled outwardly to achieve this
effect and Fig. 9 shows two chairs stacked together. For
added strength in the arms, a third attachmen~ point is
provided as shown in Fig~ 3 at the base of the C-
configuration of the arm. Thus, respective screws extendthrough the bases of the arms and into the intermediate
portions 56, 58 respectively of ~he main frame 24. Fig.
7 shows one of those screws, denoted 102, for the right
hand arm of the chair 26 and shows a plastic collar 104
behind the head of the screw. That collar of course acts
as a buffer when the chair is stacked in the same manner
as collar 100 of Fig. 4.
.
~. ,'....
.,~. ,., ~ ,.
Each of the arms is provided with an arm rest
in the form of a plastic cover, the arm rests are denoted
respectively 106 and 108 in Fig. 1. Fig. 5 shows a
sectional view through arm rest 108. Considering that
S view in conjunction with Fig. 1 it will be seen that the
portion of the arm at which the arm rest is disposed has
been formed by a flattened length of the tubing from
which the arm is formed, folded back on itself along a
length appoximating the length of the cover 108. The
cover itself is a plastic extrusion which embraces the
upper, flattened portion of the tubing and which is
trapped between that portion and the underlying folded
back portion, denoted 110 in Fig. 5. A machine screw 112
extends ~hrough a plain hole in the portion 110 and is
received in a tapped opening in the upper portion of the
tubing so that the two tubing portions can be drawn
together to trap the cover in place by means of screw
112.
As noted previously, either or both of the arms
26, 28 can be readily removed from the chair according to
requirements. One arm might be removed, for example,
when ganging the chairs as discussed above.
Snap-on plastic stops or "buffers" are provided
on the bottom limbs 42, 50 of the frame as indicated at
114 in Fig. 1. In practice, the chair will be completed
by an appropriate surface treatment on the metal frame
and panels, for example paint or an appropriate plastic
..
12 -
coating or other coveriny. Decoratlve effects may be
provided on the seat panels by perforating or otherwise
suitably treating the sheet material from which the
panels are made.
Figs. 2, 10 and 11 also illustrate the fact
that a tablet can be provided on either of the arms 26 or
28 where a writing or other work surface is required in
conjunction with the chair. In Fig. 2, reference numeral
116 denotes such a tablet on arm 26 and arrow 118 indi-
cates that the tablet is pivotally coupled to the arm.
Figs. 10 and 11 show details of the manner in which
tablet 116 is coupled to arm 26. The tablet itself is a
planar wooden member and is provided at its underside
with a hinge assembly 120. This assembly includes a
first angle member 122 which is screwed to the underside
of ~able 116 and a second angle member 124 which is
hinged to member 122 and is adapted to be coupled to the
underside of arm 26.
As best seen in Fig. 10, the two angle members
122, 124 have respective horizontal limbs 122a and 124a
which are spaced by an amount corresponding to the over-
all thickness of arm 26. Member 124 is secured by way of
its limb 124a to the underside of arm 26 by a pair of
machine screws 126 received in tapped holes on the under-
side of the arm. When tablet 116 is in its horizontal
position, the limb 122a of angle member 122 lies flat on
the top surface of the arm as best seen in Fig. 10, and
- 13 -
the tablet is maintained in a horizontal disposition.
The hinge connection between the two angle members 122,
124 allows tablet 1~6 to be raised into a generally
vertical position shown in ghost outline in Fiys. 2 and
10. As drawn, the hinge assembly 120 is not designed to
specifically hold the tablet vertical but normally the
hinge connection between the two angle members will be
sufficiently stiff that the tablet will remain in a
position to which it is moved about the hinge. However,
in an alternative arrangement suitable stops could of
course be provided.
Fig. 2 also showns in ghost outline at 128 a
wire basket which can be used for storage purposes below
the seat of the chair. The basket has not been shown in
detail; for present purposes, it is sufficient to note
that the basket will include vertical limbs 130, one at
each side and two at the rear, having lateral projections
130a at their ends designed to fit into corresponding
openings in the seat frame 82, The basket will be
designed so that those limbs can be spring biassed
inwardly to realease the projections from frame 82.
It will of course be understood that the
preceding description relates to a particular preferred
embodiment and that many modifications are possible
within the broad scope of the invention. Some of those
modifications have been indicated previously. Others
which should be noted are the fact that the main chair
3~3
- 14 -
frame 24 need not be manufactured in one piece f~om asingle length of tubing. The frame should be unitary but
could be assembled from individual frame members welded
together. The frame need not be made from circular
section tubing. The cross members 52 and 54 are prefer-
ably disposed behind the back panel 22 of the chair but
this is not essential. For example, in another embodi-
ment, cross member 54 could be disposed at the same level
as the top limbs 40, 48 of the frame loops 32, 34. Those
loops should be "closed" but this can be achieved other
than in the manner illustrated~ For example, the members
40, 48, or extensions thereof, could be welded to the
rear legs 3~, 46, or their extensions.
The seat and back panels 20, 22 could be
combined in one panelO Also, the panels themselves need
not be of the specific form shown. Open mesh panels
could be used in an alternative embodiment.
Of course, references to the use of specific
fasteners are not to be considered as limiting; generally
screw and/or rivet fastenings may be used interchange-
ably.
