US3929376A

US3929376A - Metal chair

Info

Publication number: US3929376A
Application number: US502496A
Authority: US
Inventors: Richard Kates
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-09-03
Filing date: 1974-09-03
Publication date: 1975-12-30
Anticipated expiration: 1992-12-30

Abstract

An improved lightweight metal chair having a number of structural enhancements is disclosed. The flexural rigidity of the frame of the chair seat is enhanced by counters which develop tensile forces to resist flexure incident to the loading of the chair. The legs of the chair are connected to the frame of the seat by gussets which supportingly embrace and grip one or more members of the frame of the seat. The structural interface between the frames of the seat and back of the chair include telescopic connections in which the male member depends from the frame of the seat while the female member is associated with the frame of the back. Rigid arms interconnect the frames of the seat and back. The chair is easily disassembled for compact storage.

Description

United States Patent 1 Kates 1 Dec. 30, 1975 [54] METAL CHAIR 22 Filed: Sept. 3, 1914 21 Appl.No.:502,496

[52] US. Cl 297/445; 248/188 [51] Int. Cl. A47C 1/12 [58] Field of Search 297/445, 440, 443, 450,

4/1967 Riflten 182/184 X 9/1968 Sewer 52/695 X Primary Examiner-flames T. McCall Attorney, Agent, orFirm-Burns, Doane, Swecker & Mathis [57] ABSTRACT An improved lightweight metal chair having a number of structural enhancements is disclosed. The flexural rigidity of the frame of the chair seat is enhanced by counters which develop tensile forces to resist flexure incident to the loading of the chair. The legs of the chair are connected to the frame of the seat by gussets which supportingly embrace and grip one or more members of the frame of the seat. The structural interface between the frames of the seat and back of the chair include telescopic connections in which the male member depends from the frame of the seat while the female member is associated with the frame of the back. Rigid arms interconnect the frames of the seat and back. The chair is easily disassembled for compact storage.

18 Claims, 7 Drawing Figures US Patent Dec. 30, 1975 Sheet 1 of3 3,929,376

U.S. Patent Dec. 30, 1975 Sheet20f3 3,929,376

US Patent Dec. 30, 1975 Sheet 3 of? 3,929,376

METAL CHAIR BACKGROUND OF THE INVENTION This invention relates generally to a metal chair which may be used in and around the home. More particularly, the invention relates to a metal chair which is sturdy, compact, lightweight, and which can be readily assembled and disassembled, but which nonetheless can be efficiently and inexpensively manufactured.

In recent years, the public has devoted increased attention and time to the out-of-doors (e.g., patio) living. The increased exposure of the general population to the out-of-doors has developed a considerable demand for outdoor furniture of various types including chairs for both single and plural occupants. In order to avoid problems caused by mildew, decay, and exposure to the elements, this furniture is usually fabricated entirely or principally of metal. Metal construction and the character of the use of the furniture often present a number of problems.

Outdoor furniture may be subject to heavy use and as a consequence, may often be vulnerable to failure. A chair seat frame, for instance, must be sufficiently flexurally rigid to sustain the weight of the occupants. This problem is considerably exacerbated in the case of a chair for plural occupants since the portion of the frame which undergoes the principal loading by the seated occupants is considerably longer in a chair for plural occupants than in the case of a chair for a single occupant. For this reason, this portion of the frame of the seat is subject to bending moments of greater magnitude. The magnitude of the bending moments, if sufficiently large, can cause undue deflection and/or yielding of what is optimally a rather slender structural member. Undue deflection and/or yielding of the frame of the seat can be avoided by either increasing the size of the structural member or by adding a leg intermediate the ends thereof to provide support. Both approaches clearly increase the cost, weight, bulk, ad complexity of such an article of furniture.

Another approach to problems connected with the flexural capabilities of the frame of the seat has been to employ a compression member to support the seat of the chair from below. These compression members are themselves vulnerable to buckling. To render such a member structurally adequate, it may be necessary to increase the size thereof. This remedy is undesirable for the reasons suggested earlier.

A further approach to the problem of the flexural rigidity of the frame of the seat of a chair which has been proposed employs an arcuate member to suspend the frame of the seat from the back of the chair to thereby transfer load exerted on the seat into the legs of the chair. An arcuate member, of course, is quite subject to flexure and associated stress concentrations and for this reason is inefficient as a structural member. To be effective, such a member must of necessity be unduly heavy. An arcuate member also may be costly to manufacture.

In summary, it would be desirable, if the chair seat frame undergoing the principal loading could be stiffened against flexure without adding significantly to the materials or labor required to fabricate the frame.

Not only should the chair seat frame be sufficiently flexurally rigid to sustain the usual loads, but the structural interface between the seat of the chair and the back thereof must be capable of resisting forces ex' erted as an occupant leans back or reclines against the back of the chair. This problem may be aggravated by the fact that the back of a chair is often inclined relative to the frame of the seat in a manner which results in a relatively complex connection. Clearly, the strengthening of such a connection is potentially costly in terms of materials and labor and may have an adverse effect on the desirable chair weight, bulk, and complexity.

Scveral devices of the prior art employ telescopic connections to form the structural interface between frames forming the seat and back of the chair. These telescopic connections generally employ female members rigidly connected to the frame of the seat and solid cylindrical male members rigidly connected to and extending from the frame of the back of the chair. Arrangements of this type are commonly heavily rein forced and cumbersome since the connection must be capable of resisting the tendency of the male member to buckle and the tendency of the female member to tear or collapse. Such a configuration is thus not only vulnerable to failure but is also inefficient in terms of labor and materials. Indeed, the solid cylindrical char acter of the male member is frequently extended to the frame of the back as a whole and may for this reason also increase the weight of the chair.

Ah additional structural requirement resides in the need for the legs of the chair to form a stable base securely connected with the frame of the chair. It has been proposed in this connection to enlarge the base of the chair. This can be done in various ways. For example, it has been proposed to enlarge the frame of the seat from which the legs depend. This approach, how ever, adds to the amount of materials required to fabricate the frame of the seat and may simply add useless capacity to the chair. The base may also be enlarged by splaying the legs of the chair. Splaying may render the connection of the legs to the chair vulnerable to failure and may therefore require that the connection be strengthened.

In some instances, chairs appearing in the prior art may employ flanges connected to each leg and the frame of the chair to enhance the strength of the connection therebetween. In most cases, the flanges of these arrangements are simply bolted in place and are not otherwise secured to the frame of the chair. For this reason, connections of this type may not afford sufficient structural contact to ensure solid connections between a chair and the associated legs. In those cases in which it is desirable to enlarge the base of the chair by splaying the legs, the flanges may be highly vulnerable to flexural failure and thus may be quite unsuitable. These arrangements may also be troublesome to manufacture since the leg may not be amenable to quick and accurate orientation.

It can be appreciated from the preceding discussion that outdoor furniture of the prior art which is formed of components which are sturdy may as a result be bulky and heavy in weight. The bulk and weight of this furniture often detracts from its more widespread use since most modern homes and apartments and the recreational areas associated therewith tend to be rather small. As a consequence, furniture used in and around such dwellings must not only be sturdy, but should be compact and light as well.

It is also desirable for outdoor metal furniture to be readily assembled and disassembled. Outdoor furniture is commonly shipped in disassembled form for assembly by the ultimate purchaser. Storage of these articles is also enhanced if the articles are easily disassembled into compact individual components. Since many people lack the requisite mechanical skill to assemble any but the most simple structure, it is particularly desirable that an article of outdoor furniture should be fabricated such that it can be readily assembled and disassembled by a person who is mechanically unskilled.

The problems suggested in the preceding, while not exhaustive, are among many which may tend to reduce the effectiveness and desirability of various structural features of metal furniture, particularly metal chairs. Other noteworthy problems may also exist; however, those presented in the discussion above should be suffi cient to demonstrate that metal chairs appearing in the prior art have not been entirely satisfactory, particularly with regard to structural adequacy, compactness, weight, ease of assembly and disassembly, and cost.

OBJECTS AND SUMMARY OF THE PREFERRED FORMS OF THE INVENTION In light of the foregoing, it is therefore a general object of the invention to provide a novel chair intended to obviate or minimize problems of the type noted in the preceding.

It is a particular object of the invention to provide a chair, having a frame forming the seat thereof which is sufficiently flexurally rigid, without significantly adding to the materials or labor required to fabricate the chair and without increasing the weight or cost or reducing the compactness thereof.

It is another object of the invention to provide a chair having a secure connection between each leg and the frame of the chair capable of sustaining bending moments and shear forces due to the loading of the chair.

It is still another object of the invention to provide a novel chair wherein each leg can be splayed and the connection between the leg and the frame are configured so that the splay of the leg can be quickly and accurately oriented during construction relative to the frame of the chair.

It is yet still another object of the invention to provide a novel chair wherein the structural interface between the frames forming the seat and back of the chair is simple and structurally capable of sustaining loads imposed as an occupant rests or reclines against the back of the chair.

It is a further object of the invention to provide a chair which is sturdy, and yet sufficiently light in weight that it can be readily carried from place to place and sufficiently compact that it can be used in and around a modern home.

It is still a further object of the invention to provide a chair which can be disassembled to the degree that the components can be packaged or stored in a relatively small, flat area and yet readily assembled and subsequently disassembled by a person who is mechanically unskilled.

It is yet still a further object of the invention to provide a chair which can be manufactured in a manner that makes efficient use of the materials and labor required for construction.

A novel metal chair according to one aspect of the invention includes a frame forming the seat thereof. The frame of the seat has front, side, and back portions and legs depending therefrom. A counter vertically spaced below the front portion of the frame develops tensile forces and thereby assists in resisting flexure of the front portion of the frame incident to the loading of the chair by one or more occupants.

According to another aspect of the invention, another frame forms the back of the chair and includes generally upright members connected to the back of the seat frame. The upright members are interconnected at the upper ends by an elongated top member. A plurality of suspending counters interconnect the upright members, the elongated top members, and the back portion of the frame forming the seat of the chair. These suspending counters suspend the back portion of the frame of the seat and transfer loads exerted thereon into those of the legs connected to the back portion of the frame forming the seat.

According to a further aspect of the invention, the frame forming the seat of the chair is constructed of members each forming a generally right angle in crosssection. A plurality of legs are employed to support this frame. Gussets configured to supportingly embrace and grip one or more members forming the frame of the seat connect the legs to the chair.

According to still another aspect of the invention, a slot is formed in the gussets connecting the legs to the intersection of members forming the back and side portions of the frame forming the seat of the chair. A solid cylindrical pin ridigly connected to the frame forming the seat of the chair extends upwardly through this slot and receives thereover in telescoping relation the lower ends of upright members forming the frame of the back of the chair.

THE DRAWINGS Other objects and advantages of the present invention will become apparent with reference to the detailed description to follow of a preferred embodiment thereof wherein like reference numerals have been applied to like elements and in which:

FIG. 1 illustrates a perspective view of an embodiment of the invention intended to support a single occupant;

FIG. 2 illustrates a perspective view of an alternative embodiment of the invention intended to support plural occupants;

FIG. 3 illustrates a fragmentary view in side elevation of the invention showing a portion of the structural interface between the frames forming the back and seat of the chair as well as the connection of a leg and an arm to the chair;

FIG. 4 illustrates a fragmentary, sectional view taken along lines 4-4 of FIG. 3;

FIG. 5 illustrates a fragmentary, sectional view taken along lines 55 of FIG. 3;

FIG. 6 illustrates a sectional view taken along the lines 6-6 of FIG. 5; and

FIG. 7 illustrates a perspective view of a rear corner of the frame forming the seat of the chair, a rear leg in disassembled relation therewith, and a portion of the connection between the frames forming the seat and back of the chair.

DETAILED DESCRIPTION Referring now to FIGS. 1 and 2 of the drawings, two different embodiments of the invention can be seen. The most apparent distinction between these embodiments at this point is that the chair illustrated in FIG. 1 is intended to accommodate a single occupant while that illustrated in FIG. 2 is intended to accommodate plural occupants. Both embodiments have a number of structural features in common and these features will be pointed out in the next few paragraphs with the objective of familiarizing the reader with the general structure of the invention and certain basic terms. At the outset it should be mentioned that normally the chairs of both embodiments include cushions which cover most of the framing. These cushions have been deleted in the drawings so that the various structural characteristics of the invention can be clearly illustrated.

Both embodiments employ a first frame 6 which forms the seat of the chair. The frame of the seat includes front, side, and back portions 8, l0, and 12, respectively, which are preferably formed of intersecting leg members each forming a generally right angle in cross-section, one leg member being vertically oriented while the other leg member is horizontally oriented and directed inwardly toward the interior of the frame. It should be evident from the illustrations that the span between points of vertical support of the members forming the front and back portions 8 and 12, respectively, may vary considerably in length.

In both embodiments, a plurality of legs 14 depend from the frame of the seat 6. These legs may be diagonally splayed relative to the frame of the seat, that is, the legs are spread diagonally outward from each corner of the frame of the seat to which they are connected. The actual connection between each leg 14 and the frame of the seat 6 is formed by a gusset 16 (described in more detail hereinbelow) which is rigidly connected to an associated leg and removably connected to the frame of the seat.

The chairs accommodating both single and plural occupants employ a second frame 18 which forms a back against which an occupant or occupants may recline while seated on the frame of the seat 6. The frame of the back 18 includes upright members 22 which are connected at their lower ends to the frame of the seat and also includes an elongated top member 20 which interconnects the upright members adjacent the upper ends thereof. In each embodiment certain of the upright members constitute terminal upright members 22 and each of these members comprise a lateral end of the frame of the back 18. Each of the terminal upright members 22 preferably forms a generally right angle in cross-section as may the elongated top member 20. In the case of the plural occupant embodiment illustrated in FIG. 2, the frame of the back 18 also includes intermediate upright members 24 which are disposed between the terminal upright members 22. These intermediate upright members interconnect the back portion 12 of the frame of the seat 6 and the elongated top member 20.

At least a pair of rigid arms 26 are provided in both of the embodiments illustrated in FIGS. 1 and 2. Each of these arms extends from connection with a side portion of the frame of the seat 6 to connection with a terminal upright member 22 of the frame of the back 18. The connection between a terminal upright member 22 and an arm 26 occurs at a point intermediate the ends of the terminal upright member.

The front, side, and

back portions

8, 10, and 12, respectively, of the frame of the seat 6 are resiliently interconnected by a web of strips 28 through coil springs 30. The web formed by the strips and springs 28 and 30, respectively, serves to transfer loads imposed on either of the chairs into the frame of the seat 6. Each 6 chair will, of course, be most commonly loaded by one or more seated occupants.

The particular distribution of this loading is somewhat uncertain but should be essentially symmetrical above either of two intersecting axes of symmetry of the frame of the seat 6 which coincide with the plane thereof. The distribution of loading due to seated occupants is probably best approximated by a triangular distribution, the apex of which occurs at the center of the area in which the occupant is seated. In other words, the greatest loads applied by a seated occupant probably are exerted in the center of the area in which the occupant is seated and the magnitude of the forces imposed probably decreases in an essentially linear manner away from this central area. Although, as indicated earlier, this type of loading is symmetrical, it gives rise to fairly complex shear and bending moment distributions through the frame of the seat of a chair. An examination of the shear diagram which results from a triangular distribution of forces suggests that an essentially uniform distribution of loads along the frame of the seat for the embodiments of both FIGS. 1 and 2 results.

If it is assumed, for instance, that each occupant of a chair weighs 2? and that the chair illustrated in FIG. I can accommodate one such occupant while the chair illustrated in FIG. 2 can accommodate three such occupants, then each front and back portion of the frame of the seat having a length L will receive a total load of P in the case of the embodiment of FIG. 1 and 3P in the case of the embodiment of FIG. 2. Across the entire length of the front and back portions of the seat frame, the total load is 2!, i.e., the weight ofa single occupant. Similarly, across the entire length of these members of the chair illustrated in FIG. 2 the total load applied is 6?, i.e., the total weight of three occupants each weighing 2P. In both embodiments, approximately onehalf the distributed load is probably exerted on the front portion of the frame of the seat while the remaining load is exerted on the back portion of the frame of the seat.

As a result of the loads applied as described in the preceding paragraph, bending moments are developed in the front and back portions of the frame of the seat in both embodiments. In both embodiments, the maximum bending moment occurs at the midpoint of the span of the front and back portions of the frame of the seat between the legs 14. It will be understood that the bending moment increases rather rapidly in the first one-third of the span and then changes relatively little over the middle one-third of the span. It can therefore be appreciated that the bending moment developed in the front or back portion of the frame of the seat is at or relatively near a maximum throughout the middle one-third of the span.

The members forming the frame of the seat and subject to the bending moments just described, including the front and rear portions thereof, are preferably as slender as possible to minimize the weight and cost of the chair.

The front portion of the frame of the seat is suitably provided with a construction which enhances the flexural rigidity of the frame. Preferably the frame is provided with a system of flexural counters and associated spacers. A variety of different arrangements of the counters and associated spacers could be used but two preferred approaches are illustrated, one in FIG. 1 and the other in FIG. 2.

Both of the embodiments of the invention illustrated in FIGS. I and 2 include a suitable countering means such as a tensile rod 32 operably associated with but vertically spaced below the front portion 8 of the frame of the seat 6. This rod is referred to as a tensile rod because, by virtue of the geometrical properties of the structural section formed by the front portion 8 of the frame of the seat and the tensile rod 32, the rod will only undergo tensile stresses as the frame of the seat 6 undergoes flexure. The tensile stresses developed in the tensile rod result in tensile forces which assist in resisting flexure of the front portion 8 of the frame of the seat 6. By considering the relation of the bending mo ment discussed above to the front portion of the frame of the seat, it can be appreciated that the tensile rod 32 extends along the front portion of the frame of the seat directly below the point at which the maximum moment is developed. In the embodiment illustrated in FIG. 2, the tensile rod extends along slightly more than the middle one-third of the span of the front portion 8 of the frame of the seat 6.

The tensile rods 32 of both embodiments are rigidly connected to the front portion of the frame of the seat by suitable first spacing means such as primary spacing loops 34. The tensile rod 32 and the primary spacing loops 34 are preferably welded rigidly together at each point of mutual contact shown. The primary spacing loops 34 serve in whole or in part to maintain the tensile rod a fixed vertical distance below the front portion 8 of the frame of the seat 6. The magnitude of the vertical distance should be sufficient to preclude the development of stresses in the tensile rod greater than the yield stress of the particular material composing the rod. Preferably, the primary spacing loops 34 are integral with the tensile rod so that the tensile rod and the primary spacing loops can be formed during manufacture from a single length of material.

In the case of the embodiment illustrated in FIG. 2, secondary spacing means or loops 36 which are not integral with the tensile rod are employed to further ensure the proper positioning of the tensile rod relative to the front portion of the frame of the seat. In other words, in the embodiment illustrated in FIG. 2, primary spacing loops 34 which are integral with the tensile rod 32 are employed to maintain the tensile rod in position but additional, secondary spacing loops 36 may also be employed between the primary spacing loops to interconnect and maintain the relative positions of the tensile rod and the front portion of the frame of the seat.

The result of the two different arrangements of the tensile rod and spacing loops described in the preceding paragraphs is that in the embodiment illustrated in FIG. 1, the primary spacing loops 34 interconnect the tensile rod 32 and the front portion 8 of the frame of the seat 6 to form a rigid, essentially triangular lattice. The lattice is symmetrical about a generally vertical axis of symmetry passing through the midpoint of the front portion of the frame of the seat. This triangular configuration can be perhaps best appreciated by ex amining the dashed lines appearing in FIG. I. The dashed lines represent the directions along which forces developed in the spacing loops act in maintaining the position of the tensile rod 32 during flexure. In contrast, in the embodiment illustrated in FIG. 2, the primary and

secondary spacing loops

34 and 36 interconnect the tensile rod 32 and the front portion 8 ofthe frame of the seat 6 to form a rigid, essentially rectilinear lattice. The lattice shown in FIG. 2 is also symmetri- 8 cal about a generally vertical axis of symmetry passing through the midpoint of the front portion of the frame of the seat. The rectilinear character of this lattice can be appreciated upon examination of the dashed lines appearing in FIG. 2 which are used in the same manner as the dashed lines of FIG. 1.

In protecting the back portion 12 of the frame of the seat 6 from undue flexure, a somewhat different approach is taken.

As noted above, the frame of the back 18 includes upright members connected to the back portion 12 of the frame of the seat 6 and interconnected at the upper ends thereof by an elongated, top member 20. In the case of the embodiment illustrated in FIG. 2, intermediate upright members 24 are provided between the terminal upright members 22. As will be better appreciated in the course of subsequent discussion, these intermediate upright members 24 function as counters to at least partially suspend the back portion 12 of the frame of the seat 6.

As illustrated in FIGS. 1 and 2, each embodiment of the invention employs a plurality of suitable suspending, countering means in the form of hangers 42 to interconnect the upright members, the elongated top member, and the back portion of the frame of the seat. This is not to say that each hanger connects all three, but rather, as is illustrated in either FIGURE, each hanger interconnects at least two of the three structures mentioned, and there is a sufficient plurality of hangers to interconnect all three structures. The hangers 42 are preferably thin, elongated strips each essentially rectangular in cross-section and insufficiently rigid to sustain compressive loads of any significance directed along the longitudinal axis thereof. The hangers 42 serve to suspend the back portion 12 of the frame of the seat 6 from the upright members and the elongated top member. The hangers thus transfer at least a portion of the loads exerted on the back portion of the frame of the seat into those of the legs connected to that portion of the frame of the seat. The suspension of the back portion of the frame of the seat serves to reduce the bending moments that develop therein by providing support for the back portion of the frame of the seat from above.

In order to optimize the effectiveness of the suspension of the back portion of the frame of the seat, the hangers 42 are arranged to form a triangular lattice with the upright members, elongated top members, and the back portion of the frame of the seat. The triangular lattice formed thereby is symmetrical about an axis passing through the midpoint of the frame of the back of the chair. This symmetrical, triangular form requires a minimal number of hangers and also provides some reinforcement against skewing of the frame from the rectangular configurations illustrated.

In the case of the embodiment illustrated in FIG. 2, it should be noted that the intermediate upright members 24 are two in number and are mutually interconnected by a portion of the triangular lattice described in the preceding paragraph to form a median panel 44. The median panel 44 and thus the middle portion of the frame of the seat is suspended as a unit by several hangers. These hangers extend diagonally from each of the terminal upright members 22 and the elongated top member 20 to one of the intermediate upright members 24 and the back portion of the frame of the seat 6. Such an arrangement is useful in suspending the middle portion of the back portion 12 of the frame of the seat 6 9 undergoing bending moments of the greatest magnitude.

As should be readily apparentfrom FIGS. 1 and 2 a plurality of legs is connected to the frame of the seat 6 and each leg extends downwardly from a comer thereof to support the frame of the seat. As indicated earlier, each leg I4 is connected to the frame of the seat through a suitable gusseting means such as the gusset 16. As perhaps best illustrated in FIG. 5, each gusset is connected to the frame of the seat in such a manner that it supportingly braces and grips, about at least upper and lower portions, one or more members forming the frame of the seat. The gusset in this way rigidly connects a leg to the frame of theseat.

As perhaps best illustrated in FlGS.=4 and 7, each gusset [6 preferably forms a right angle 'and extends around a comer formed by the intersection of the members forming front or back portions 8 or 12 and members forming side portions of the frame of the seat. As can be seen from FIG. 4 each gusset is thus symmetrically arranged around a corner and therefore supportingly embraces and grips equal segments of the intersecting members.

Each gusset supportingly embraces and grips members forming the frame of the seat through top and bottom flanges interconnected by a planar portion. As best illustrated in FIGS. 5 and 7, each gusset includes at least one top flange 46 which covers a segment 48 of the horizontal leg of one or more members forming the frame of the seat. Each gusset also includes at least one bottom flange 50 having a horizontal segment 52 extending inwardly beneath a segment 54 of the lowermost edge of the vertical leg of the right angle formed .by members forming the frame of the seat. These two flanges, that is, the top flange 46 and the bottom flange 50 are interconnected by a planar portion 56 which covers a segment 58 of a vertical leg of the right angle fonned by members forming the frame of the seat.

Suitable fasteners 60 extend through the planar portion 56 and through the vertical leg of the member forming the frame of the seat to connect the gusset to the frame of the seat as illustrated in N68. 5 and 7. Once these fasteners are tightened as illustrated in FIG. 5, the top and bottom flanges and the planar portion therebetween supportingly embrace and grip one or more members forming the frame of the seat. In this way, a solid connection is formed between the leg and the chair and the stability of the members forming the frame of the seat is considerably enhanced. As will be more clearly appreciated from subsequent discussion, this feature is also important in two further aspects, viz., in reducing the unsupported span of the members forming the frame of the seat and in ensuring a solid structuralinterface between the frames of the seat and the back 6 and [8, respectively.

With respect to reducing the unsupported span of the members forming the frame of the seat, it can be appreciated from an examination of FIG. 5 that each gusset 16 preferably includes two mutually orthogonal limbs 62 each of which carry top and

bottom flanges

46 and 50 and an interconnecting planar portion 56. The limbs 62 extend toward the midpoints of the members intersecting to form the frame of the seat and thus serve to reduce the unsupported span of these members. FIGS. 3 and 4 clearly illustrate this feature.

The fasteners 60 mentioned earlier each penetrate a limb 62 of a gusset and one of the members intersecting to form the frame of the seat to secure the gusset to the frame of the seat. The resulting reduction of the unsupported span of the members forming the frame of the seat is important because the bending moments developed therein are a function of the unsupported span. Any reduction in the unsupported span of a member serves to reduce the bending moment developed therein so long as the loading of the member remains unchanged.

Preferably the legs 14 employed to support the frame of the chair are generally rectangular in cross-section although any other cross-sectional configuration can be used. Optimally, each leg supporting a comer of the frame of the seat has at least one orthogonal corner 64 which is matingly receivable in the interior 66 of the generally right angle formed by each gusset. The most preferable configuration is illustrated in FIG. 7 'in which the orthogonal surfaces of the leg forming the orthogonal comer 64 seat against the surfaces of the gusset which intersect to form the right angle thereof. During manufacturing of the gusset, the orthogonal corner 64 of each leg can be inserted into the interior angle of the gusset and in this way the leg can be quickly and accurately oriented for securement in place.

The securement of the leg to the gusse't is further enhanced by vertical .portions of the bottom flanges 50. As illustrated in FIG. 7 each bottom flange 50 extends arcuately downwardly from the horizontal segment 52 thereof to form a vertical segment 68. The vertical segments of the twp bottom flanges 50 at least partially enclose and grip the leg to which the gusset is connected. Thus, with the leg seated inside the gusset and at least partially enclosed by the vertical segments 68 of the bottom flanges 5.0, the leg can be permanently and accurately connected :to' the gusset by welding or otherwise.

Optimally these legs are splayed to broaden the base and thereby enhance the stability of the chair. Most desirably the base of the chair is broadened in both directions, i.e., both forwardly or reawardly and laterally. This arrangement is most effectively accomplished by bending each leg about diagonal axes to thus diagonally splay the leg selative to its associated gusset and the frame of the seat. A diagonal axis is an axis passing through the comers of the rectangular leg across a corner of the frame of the seat. Representative diagonal axes about which a leg may be bent are represented by the dashed lines S-S shown in FIGS. 4 and 7.

To provide symmetry and optimal stability, each leg is bent about axes passing through the same two corners at points near the lower portion of the gusset and again near the lower end of the leg. The bending near the lower end of the leg provides vertical contact between the floor or other surface and the leg of the chair.

The embodiments illustrated in FIGS. 1 and 2 each include a pair of rigid arms 26 which each extend generally upwardly from connection with a side portion 10 of the frame of the seat to connection with a terminal upright member 22 at a point intermediate the ends thereof. The interconnection of each arm between the two frames serves to reinforce the terminal upright members 22 in such a way as to assist in the resistance of flexural loads.

Preferably, though not necessarily, the rigid arms 26 are formed of a tubular material. The tubular quality of the arm affords a significant advantage in effecting the connection between each arm and the

frames

6 and 18.

frame. This flattening permits the efiective use of a fastener such as the threaded fastener 40 illustrated or a rivet which passes through the relatively thin planar portions to connect the arm 26 to one of the two frames.

As previously indicated, the frames forming the seat and back of the chair are preferably rectangular and interconnected. Resistance to loads applied to the frame of the back [8 is provided by the terminal upright members 22, the intermediate upright members 24 serving principally as counters to suspend the back portion 12 of the frame of the seat. Intermediate upright members can be connected to the back portion of the frame of the seat in any desired manner, for instance by simple threaded fasteners. The connection between the terminal upright members and the frame of the seat, however, must be sufficiently durable to sustain the portion of the loading exerted on the frame of the back and not restrained by the rigid arms 26.

The problem of providing an adequate structural interface between the frames of the seat and the

back

6 and 18, respectively, is exacerbated by the fact that the frame of the back is commonly inclined relative to the frame of the seat and little space is available for any reinforcement.

The metal chairs of the present invention include a unique telescoping joint which is structurally interrelated with the gusseted connection of the rear legs of the chair to the frame of the seat and which provides significant structural support therefor. As illustrated in FIG. 7 a slot 70, preferably U-shaped, is formed in the top flange 46 of each gusset supporting the intersection of members fonning the back and side portions of the frame of the seat. The slot 70 extends diagonally into the right angle fonned by the gusset. A solid cylindrical pin 72 is ri'gily connected to the interior 74 of each intersection of the vertical legs of the membersforming the side and back portions of the frame of the seat as illustrated in FIGS. 4, 5, and 7. The cylindrical pin 72 extends upwardly through the slot 70 of each gusset connected to a rear corner of the frame of the seat.

Bach terminal upright member 22 has a lower portion 76 which can be telescoped over one of the cylindrical pins 72 to connect the frames of the back and the seat. As illustrated in FIG. 6 the lower portion 76 of each terminal upright member 22 is preferably reconfigured during manufacture into a generally tubular portion capable of sliding snugly over one of the cylindrical pins 72.

This particular arrangement with a solid cylindrical pin extending from the frame of the seat avoids the enlargement of the joint which would be required if the female portion of the joint extended upwardly from the frame of the seat and the male portion depended from the frame of the back. This arrangement also stabilizes the gussets, rear legs and seat frame at the point of their intersection.

SUMMARY OF MAJOR ADVANTAGES It will be appreciated that in providing a metal chair according to the present invention certain significant advantages are obtained.

of particular importance is the advantage that the frame of the seat of the chair is made sufficiently flexurally rigid that loads applied thereto can be sustained 12 without adding significant amounts of materials or employing much additional labor.

It is another advantage that the chair legs can be splayed in two directions to form a stable base and yet are securely connected to the frame of the chair in a manner such that bending moments and shear forces introduced into the connection can be readily sustained. Also, each leg is connected to. the chair in such a way that the leg can be quickly and accurately oriented relative to the frame of the chair during fabrication thereof.

Still another significant advantage of the invention resides in the fact that the structural interface between the frames forming the seat and back of the chair is quite simple and yet structurally capable of sustaining loads normally imposed on the frame of the back.

The metal chair of the present invention is quite sturdy, light in weight, and compact. The chair can be disassembled and the components packaged or stored in a relatively small, flat area and readily assembled by a person who is mechanically unskilled.

in describing the invention, reference has bee made to a preferred embodiment. However, those skilled in the art and familiar with the disclosure of the invention may recognize additions, deletions, substitutions, or other modifications which would fall within the purview of the invention as defined in the claims.

What is claimed is:

l. A metal chair comprising:

a seat frame forming a seat portion of the chair, said seat frame including a front portion,

a back portion, and

side portions interconnecting said front and back portions, a plurality of support legs depending from said frame,

and countering means connected directly to one of said frame portions for resisting flexture of said frame in response to the application of a load thereupon, said countering means including a tensile rod whose ends terminate short of said support legs, and

plural spacer portions for connecting said tensile rod directly to said one frame portion exclusive of connection to said support legs to space said tensile rod below said one frame portion in the region of maximum bending thereof, so that downward flexure of said front frame portion develops tensile forces in said tensile rod which resist such downward flexure.

2. A chair according to claim I wherein said one seat frame portion comprises said front frame portion; said tensile rod extending parallel to said seat front frame portion.

3. A chair according to claim 2 wherein said spacer portions are formed by integral curved extensions of said tensile rod.

4. A chair according to claim 3 wherein each of said integral curved extensions comprises:

a first section that curves upwardly from an end of said tensile rod into welded connection with said front frame portion;

a second section which extends downwardly toward said tensile rod, and

a third section which curves upwardly into welded connection with said front frame portion.

13 5. A chair according to claim 4 wherein said third sections of said spacer portions are welded to one another.

6. A chair according to claim 1 wherein said front,

back, and side frame portions are formed from angle members having leg sections forming a generally right angle in cross section, one leg section beingdirected horizontally inward toward the interior of said seat frame and the other leg section being directed vertically downward; said angle members being arranged to form a rectangle having four comers; a plurality of gusseting means disposed at each comer for connecting each support leg to a pair of intersecting ones of said frame portions; said gusseting means comprising:

a pair of generally vertical gusset plate portions extending transversely to one another and intersecting to form a vertical interior angle,

a pair of horizontal top flanges mounted at upper ends of said vertical plate portions and extending across segments of said horizontal leg sections of 2 said pair of intersecting frame portions, a pair of bottom flanges connected to said vertical plate portions; said bottom flanges including: generally horizontal support portions disposed below said horizontal flanges in supporting engagement with the vertical leg sections'of said pair of frame portions, and

generally vertical support portions extending downwardly from said horizontal support portion and being spaced from one another to receive a support leg therebetween and to support said support leg with said support leg being rigidly coupled to said gusset means and nestingly seated within said vertical interior angle defined by said vertical plate portions.

7. A metal chair comprising:

a rectangular first frame having front, side, and back frame portions formed from angle members each having leg sections forming a generally right angle in cross section, one leg section being directed vertically downward;

said angle members being arranged to form a rectangle having four comers;

a plurality of support legs extending downwardly from and supporting said first frame at the corners thereof; and

plurality of gusseting means disposed at each corner for connecting each support leg to a pair of intersecting ones of said frame portions, said gusseting means comprising: a pair of generally vertical gusset plate portions extending transversely to one another and intersecting to form a vertical interior angle, a pair of horizontal top flanges mounted at upper ends of said vertical plate portions and extending across segments of said horizontal leg sections of said pair of intersecting frame portions; a pair of bottom flanges connected to said vertical plate portions, said bottom flanges including: generally horizontal support portions disposed below said horizontal flanges in supporting engagement with the vertical leg sections of said pair of frame portions, and

generally vertical support portions extending downwardly from said horizontal support portions and being spaced from one another to receive a support leg therebetween and to support said support leg with said support leg 1-14 beingv rigidly coupled to said gusset means and nestinglyseated within said vertical interior angle defined by said vertical plate portions.

8. A metal chair according to claim 7 wherein said gusset means is secured to said pair of intersecting frame portions by a. pair of threaded fasteners extending through said vertical plate portions and said vertical leg sections of said frame portions; said support leg being rectangular in cross section and including a corner being conformably configured to said vertical interior angle in which it is nestingly seated.

9. A metal chair according to claim 7 wherein said bottom flanges each comprise generally arcuate shaped members, with the upper ends of said arcuate members curving generally horizontally to define said horizontal support portions, and with the lower ends of said arcuate members curving generally vertically to define said vertical support portions.

10. A chair as defined in claim 1 wherein:

said first spacing means interconnect said tensile rod and ,said front portion of said seat frame to form a rigid, essentially triangular lattice therebetween,

said lattice being symmetrical about a generally vertical axis passing through the midpoint of said front portion of said seat frame.

11. A chair as defined in claim I wherein:

said first spacing'means interconnect said tensile rod and said front portion of said seat frame to form a rigid, essentially rectilinear lattice therebetween,

12. A chair as defined in claim I further comprising:

a second frame forming a back of said chair against which an occupant may recline while seated on said seat frame, said second frame including generally upright members connected to said back portion of said seat frame and interconnected at the upper ends thereof by an elongated, top member; and

a plurality of suspending means interconnecting said upright members, said elongated top members, and said back portion of said seat frame for suspending said back portion of said seat frame and transferring at least a portion of the loads exerted on said back portion of said seat frame, incident to said loading of said chair, into those of said legs connected to said back portion of said seat frame, said suspending means comprising:

a first hanger bar interconnected between one of said upright members and said back portion of said seat frame;

a second hanger bar interconnected between another of said upright members and said back portion of said seat frame;

a third hanger bar interconnected between said one upright member and said top member, and

a fourth hanger bar interconnected between said other upright member and said top member.

13. A chair as defined in claim 12 wherein:

said plurality of suspending bars interconnect said upright members, said elongated top member, and said back portion of said seat frame to form a triangular lattice symmetrical about a generally vertical axis passing through the midpoint of said second frame.

l4. A chair as defined in claim 13 wherein said upright members include:

terminal upright members each comprising a lateral end of said second frame and operable to flexurally resist loads imposed on said second frame; and

intermediate upright members each located between said terminal uprights and operable to at least partially suspend said back portion of said first frame when subject to said loading.

15. A chair as defined in claim [3 further comprising:

at least a pair of rigid arms each extending generally upwardly from a side portion of said first frame to a point intermediate the ends of a terminal upright member of said second frame.

16. A chair as defined in claim 4 further comprising:

a slot in said top flange of each of said gusseting means supporting the intersection of back and side frame portions of said seat frame, said slot extending diagonally into the angle formed thereby;

a solid, cylindrical pin rigidly connected to the interior of the intersection of said vertical leg sections of each pair of said intersecting side and back portions of said seat frame and extending upwardly through said slot of each of said gusseting means; and

a rectangular, second frame forming a back of said chair against which an occupant may recline while seated on said seat frame, said second frame in- 16 cluding a generally upright members each having a lower portion telescopable over one of said cylindrical pins to connect said seat and second frames. 17. A chair as defined in claim 7 wherein:

each support leg supporting said first frame is bent about diagonal axes to diagonally splay said support leg relative to said gusseting means and said first frame.

18. A chair as defined in claim 7 further comprising:

a slot in said top flange of each of said gusseting means supporting the intersection of back and side frame portions of said first frame, said, slot extending diagonally into said right angle formed thereby;

a solid, cylindrical pin rigidly connected to the interior of the intersection of said vertical leg sections of each pair of said intersecting side and back frame portions of said first frame and extending upwardly through said slot of each of said gusseting means; and

a rectangular, second frame forming a back of said chair against which an occupant may recline while seated on said first frame, said second frame including generally upright members each having a lower portion telescopable over one of said cylindrical pins to connect said first and second frames.

t i t 1

Claims

1. A metal chair comrising: a seat frame forming a seat portion of the chair, said seat frame including a front portion, a back portion, and side portions interconnecting said front and back portions, a plurality of support legs depending from said frame, and countering means connected directly to one of said frame portions for resisting flexture of said frame in response to the application of a load thereupon, said countering means including a tensile rod whose ends terminate short of said support legs, and plural spacer portions for connecting said tensile rod directly to said one frame portion exclusive of connection to said support legs to space said tensile rod below said one frame portion in the region of maximum bending thereof, so that downward flexure of said front frame portion develops tensile forces in said tensile rod which resist such downward flexure.

2. A chair according to claim 1 wherein said one seat frame portion comprises said front frame portion; said tensile rod extending parallel to said seat front frame portion.

4. A chair according to claim 3 wherein each of said integral curved extensions comprises: a first section that curves upwardly from an end of said tensile rod into welded connection with said front frame portion; a second section which extends downwardly toward said tensile rod, and a third section which curves upwardly into welded connection with said front frame portion.

5. A chair according to claim 4 wherein said third sections of said spacer portions are welded to one another.

6. A chair according to claim 1 wherein said front, back, and side frame portions are formed from angle members having leg sections forming a generally right angle in cross section, one leg section being directed horizontally inward toward the interior of said seat frame and the other leg section being directed vertically downward; said angle members being arranged to form a rectangle having four corners; a plurality of gusseting means disposed at each corner for connecting each support leg to a pair of intersecting ones of said frame portions; said gusseting means comprising: a pair of generally vertical gusset plate portions extending transversely to one another and intersecting to form a vertical interior angle, a pair of horizontal top flanges mounted at upper ends of said vertical plate portions and extending across segments of said horizontal leg sections of said pair of intersecting frame portions, a pair of bottom flanges connected to said vertical plate portions; said bottom flanges including: generally horizontal support portions disposed below said horizontal flanges in supporting engagement with the vertical leg sectIons of said pair of frame portions, and generally vertical support portions extending downwardly from said horizontal support portion and being spaced from one another to receive a support leg therebetween and to support said support leg with said support leg being rigidly coupled to said gusset means and nestingly seated within said vertical interior angle defined by said vertical plate portions.

7. A metal chair comprising: a rectangular first frame having front, side, and back frame portions formed from angle members each having leg sections forming a generally right angle in cross section, one leg section being directed vertically downward; said angle members being arranged to form a rectangle having four corners; a plurality of support legs extending downwardly from and supporting said first frame at the corners thereof; and a plurality of gusseting means disposed at each corner for connecting each support leg to a pair of intersecting ones of said frame portions, said gusseting means comprising: a pair of generally vertical gusset plate portions extending transversely to one another and intersecting to form a vertical interior angle, a pair of horizontal top flanges mounted at upper ends of said vertical plate portions and extending across segments of said horizontal leg sections of said pair of intersecting frame portions; a pair of bottom flanges connected to said vertical plate portions, said bottom flanges including: generally horizontal support portions disposed below said horizontal flanges in supporting engagement with the vertical leg sections of said pair of frame portions, and generally vertical support portions extending downwardly from said horizontal support portions and being spaced from one another to receive a support leg therebetween and to support said support leg with said support leg being rigidly coupled to said gusset means and nestingly seated within said vertical interior angle defined by said vertical plate portions.

8. A metal chair according to claim 7 wherein said gusset means is secured to said pair of intersecting frame portions by a pair of threaded fasteners extending through said vertical plate portions and said vertical leg sections of said frame portions; said support leg being rectangular in cross section and including a corner being conformably configured to said vertical interior angle in which it is nestingly seated.

10. A chair as defined in claim 1 wherein: said first spacing means interconnect said tensile rod and said front portion of said seat frame to form a rigid, essentially triangular lattice therebetween, said lattice being symmetrical about a generally vertical axis passing through the midpoint of said front portion of said seat frame.

11. A chair as defined in claim 1 wherein: said first spacing means interconnect said tensile rod and said front portion of said seat frame to form a rigid, essentially rectilinear lattice therebetween, said lattice being symmetrical about a generally vertical axis passing through the midpoint of said front portion of said seat frame.

12. A chair as defined in claim 1 further comprising: a second frame forming a back of said chair against which an occupant may recline while seated on said seat frame, said second frame including generally upright members connected to said back portion of said seat frame and interconnected at the upper ends thereof by an elongated, top member; and a plurality of suspending means interconnecting said upright members, said elongated top members, and said back portion of said seat frame for suspending said back portion oF said seat frame and transferring at least a portion of the loads exerted on said back portion of said seat frame, incident to said loading of said chair, into those of said legs connected to said back portion of said seat frame, said suspending means comprising: a first hanger bar interconnected between one of said upright members and said back portion of said seat frame; a second hanger bar interconnected between another of said upright members and said back portion of said seat frame; a third hanger bar interconnected between said one upright member and said top member, and a fourth hanger bar interconnected between said other upright member and said top member.

13. A chair as defined in claim 12 wherein: said plurality of suspending bars interconnect said upright members, said elongated top member, and said back portion of said seat frame to form a triangular lattice symmetrical about a generally vertical axis passing through the midpoint of said second frame.

14. A chair as defined in claim 13 wherein said upright members include: terminal upright members each comprising a lateral end of said second frame and operable to flexurally resist loads imposed on said second frame; and intermediate upright members each located between said terminal uprights and operable to at least partially suspend said back portion of said first frame when subject to said loading.

15. A chair as defined in claim 13 further comprising: at least a pair of rigid arms each extending generally upwardly from a side portion of said first frame to a point intermediate the ends of a terminal upright member of said second frame.

16. A chair as defined in claim 4 further comprising: a slot in said top flange of each of said gusseting means supporting the intersection of back and side frame portions of said seat frame, said slot extending diagonally into the angle formed thereby; a solid, cylindrical pin rigidly connected to the interior of the intersection of said vertical leg sections of each pair of said intersecting side and back portions of said seat frame and extending upwardly through said slot of each of said gusseting means; and a rectangular, second frame forming a back of said chair against which an occupant may recline while seated on said seat frame, said second frame including a generally upright members each having a lower portion telescopable over one of said cylindrical pins to connect said seat and second frames.

17. A chair as defined in claim 7 wherein: each support leg supporting said first frame is bent about diagonal axes to diagonally splay said support leg relative to said gusseting means and said first frame.

18. A chair as defined in claim 7 further comprising: a slot in said top flange of each of said gusseting means supporting the intersection of back and side frame portions of said first frame, said, slot extending diagonally into said right angle formed thereby; a solid, cylindrical pin rigidly connected to the interior of the intersection of said vertical leg sections of each pair of said intersecting side and back frame portions of said first frame and extending upwardly through said slot of each of said gusseting means; and a rectangular, second frame forming a back of said chair against which an occupant may recline while seated on said first frame, said second frame including generally upright members each having a lower portion telescopable over one of said cylindrical pins to connect said first and second frames.