CA1249503A - Chair - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

CHAIR
A stacking chair having a unitary tubular frame supporting seat and back panels. The frame is formed in one piece from circular section tubing and defines a pair of closed loops at opposite sides of the chair forming the legs and two cross members behind the back panel.
The back panel is rolled over the tubular frame at the top and sides and defines hand grip openings at the top corners and in the centre region of the back just below the lower cross member. The seat is made of a peripheral frame covered by a sheet steel member which is rolled over the frame except at the sides where the sheet member overhangs the chair frame and is secured thereto.

Description

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 .

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 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 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.

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.

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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 ..

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 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 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.

Claims (12)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A chair comprising a seat panel, a back panel and a unitary tubular frame supporting said panels, the frame being shaped to define a pair of closed loops at opposite sides of the chair, 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, said limbs forming the rear legs of the respective loops having portions which extend upwardly above said top limbs and to which said back panel is secured, the frame further including a first cross member joining said upwardly extending limb portions and a second cross member coupling said top limbs, said frame cross members comprising the only portions of the frame connecting the loops, said seat panel being supported on and secured to said top limbs of the respective loops and serving as a structural member maintaining the required spacing of said loops.

2. A chair as claimed in claim 1, wherein said second cross member is disposed behind said back panel and couples said top limbs by way of intermediate frame portions exten-ding upwardly from the respective top limbs inwardly of and secured to said upwardly extending portions of the rear leg limbs.

3. A chair as claimed in claim 2, wherein said back panel defines an opening, for use in lifting the chair, said opening being disposed immediately below said second cross member and the panel being shaped so that said opening presents a smooth edge to the hand of a person lifting the chair.

4. A chair as claimed in claim 2, wherein said back panel overlies both of said first and second cross members, wherein at least said first cross member and said frame portions to which the back panel is secured are of circular shape in cross section, and where said back panel comprises a sheet form member marginal por-tions of which are rolled over said cylindrical frame portions whereby said marginal portions of the panel present a smooth external surface.

5. A chair as claimed in claim 4, wherein said back panel includes a central marginal portion which is rolled over said first cross member, and cut-outs at respectively opposite ends of said central portion through which portions of the chair frame are exposed, providing hand grips.

6. A chair as claimed in claim 1, wherein said loops of the frame are disposed in respective planes which are angled outwardly towards the bottom of the chair to an extent sufficient to permit the chair to be stacked with other similar chairs.

7. A chair as claimed in claim 6, further compri-sing respective arms each of a generally C-shaped confi-guration comprising a bottom limb, a top limb and a base, the bottom limbs of the respective arms being removably secured to lower surfaces of said top limbs of the frame with the bases of the arms at the rear of the chair and the top limbs projecting forwardly, the arms being arranged to permit stacking of the chair with other similar chairs, primarily from the front.

8. A chair as claimed in claim 7, wherein each said arm is formed from a generally tubular member the shape of which is distorted along at least the lower limb of the member to a profile designed to permit the arm to seat snugly on said top limb of the frame.

9. A chair as claimed in claim 8, wherein said top limb of each arm includes a flattened outer portion which is folded back on itself to define respective upper and lower superposed flattened parts, and wherein the arm is provided with an arm rest comprising a cover on said upper part trapped between said upper and lower parts.

10. A chair as claimed in claim 1, wherein said seat comprises a peripheral frame of circular cross-section and a panel of sheet material secured to said frame with marginal portions of the sheet rolled over the frame to present a smooth external profile and portions of said sheet overhanging the frame at opposite sides of the seat and secured to the chair frame.

11. A chair as claimed in claim 1, having at least one arm coupled to said frame and a tablet pivotally coupled to said arm for movement between a generally horizontal position in which the tablet defines a work surface, and a raised inoperative position.

12. A chair as claimed in claim 1 in combination with wire frame basket releasably coupled to said chair and disposed below the seat.