WO2001037709A2

WO2001037709A2 - Folding chair

Info

Publication number: WO2001037709A2
Application number: PCT/US2000/041286
Authority: WO
Inventors: L. E. Atkins; Richard D. Smith; David J. Laws; Dave Spendlove
Original assignee: Mity-Lite, Inc.
Priority date: 1999-10-22
Filing date: 2000-10-19
Publication date: 2001-05-31
Also published as: WO2001037709A3; AU4301201A

Abstract

A folding chair (10), and/or a stackable/storable folding chair system (60) having: a frame (14) with a curved spline profile, and a seat (150) and legs (40, 42) which collapse into a volume defined by the frame, for increased stacking density and more stable stacking; a folding mechanism (100) which provides strength characteristics and folds upon itself to save space, and a safe stopper member (124, 128) for providing a limited opened position, and to resist pinching of user's extremities; a kick-out tab (144) for facilitating opening of the folding mechanism, and thus the chair; a flexible back support (156), and a lumbar support member (160) for comfort; a projecting alignment member (200) associated with the seat for stacking stability; and indexing feet (210, 214) with projections for stacking stability.

Description

FOLDING CHAIR

BACKGROUND OF THE INVENTION

1. The Field of the Invention. The present invention relates generally to a folding chair, and/or a stackable/storable folding chair system. More particularly, the present invention relates to a folding chair having (1) a frame with a curved spline profile, and a seat and legs which collapse into a volume defined by the frame, for increased stacking density and more stable stacking; (2) a folding mechanism which provides strength characteristics and folds upon itself to save space, and a safe stopper member for providing a limited opened position, and to resist pinching of a user's extremities; (3) a kick-out tab for facilitating opening of the folding mechanism, and thus the chair; (4) a flexible back support, and a lumbar support member for comfort; (5) a projecting alignment member associated with the seat for stacking stability; and (6) indexing feet with projections for stacking stability.

2. The Background Art.

Folding chairs are often used in situations in which it is desirable or necessary to provide varying numbers and/or varying layouts of chairs, such as during conventions, seminars, conferences, etc. In addition, folding chairs are often used in multipurpose areas in which chairs are used for some functions, but a large open space is required for other functions. For example, some organizations have buildings with a multipurpose room which may be used for banquets, seminars, conventions, etc., with chairs set up, or for a dance, sporting event, etc., with the folding chairs removed.

It is desirable that the folding chairs be capable of being folded and stacked for storage so that the chairs take up less room when they are not required. It will be appreciated that some situations or events will require thousands of folding chairs, all of which may need to be folded and stored at any given period. Thus, the chairs must be folded and stored such that they have a high storage density. It will be appreciated that any extra thickness of a chair when folded becomes significant when numerous folding chairs are involved. For example, with a thousand stacked folding chairs, a folding chair which saves one extra inch in the folded position results in over 80 feet of saved storage space.

One disadvantage with many prior art folding chairs is the bulk or thickness of the chair in the folded position. Many typical folding chairs still remain several inches thick in the folded position, and thus are less dense when stored. For example, many typical folding chairs have seats which fold adjacent to or abutting the legs, and/or have front and back legs which fold against one another, such that the thickness of the chairs in the folded position comprises the thickness of both the front and rear legs, and/or the thickness of the legs and the seat. Another disadvantage of many conventional folding chairs is that they fold awkwardly, with bulky folded configurations and/or various protruding members.

In addition, it is desirable that the folding chairs be easily storable or stackable, and be stable when stored/stacked. Many typical prior art folding chairs are stored merely by leaning one chair against a wall and subsequent chairs in a series against the first chair. It will be appreciated that a plurality of folding chairs stacked against a wall have a potential domino effect, with all of the chairs subject to being knocked over. Other prior art folding chairs have complicated and expensive hanging rack systems. For example, a wheeled cart might have a plurality of hanging members from which a plurality of folding chairs are suspended. One disadvantage of these types of systems is that chairs on the end of the hangers tend to fall off the rack, and the wheeled racks are difficult to move and maneuver.

Some types of prior art folding chairs have back rest portions which protrude from the chair and into an adjacent folding chair. For example, a folding chair may have a back portion which curves outwardly to protrude from the frame of the chair, and into the frame of and adjacent folding chair. Although this relationship allows the chairs to be stored with greater density, the chairs tend to be unstable in a stored position. The broad rounded backs of the chairs act as ramps which fail to resist movement of an adjacent chair. In addition, the chairs are still relatively thick and bulky.

It also is desirable that the chairs be easy to set up and take down, or fold and unfold. It will be appreciated that there is considerable time involved in setting up and taking down thousands of chairs. One disadvantage of many prior art folding chairs is that they are difficult to both unfold and fold. For example, most folding chairs require the person to use both hands to fold and unfold the chair. For example, one hand usually has to grasp the back of the chair while the other hand has to grab and pivot the seat in or out.

It also is desirable that the chairs be comfortable. Typical prior art folding chairs have rigid metal seats and seat backs which can be hard and uncomfortable. One disadvantage of many prior art folding chairs is that the chairs either fold well and are uncomfortable, or are comfortable without folding well. Thus, there tends to be a trade off between comfort and foldability. Some chairs provide a cushion.

But these chairs still utilize the rigid metal seat bottoms and seat backs, and the cushions tend to make the chairs even thicker when folded.

In addition, it is desirable that the chair provide proper support, or be ergonomically designed. One disadvantage of many prior art chairs is that the angle between the back rest and the seat is dictated by the folding mechanism of the chair. Thus, in an effort to create a folding chair, the relative angles of the back rest and seat are often compromised to obtain a chair that folds.

Another disadvantage of many typical prior art folding chairs is that they have a relatively small back support which may not adequately support a user's back. The small back support is often a function of the folding configuration of the chair. Again, the back support is often compromised in order to obtain a chair that folds. For example, the seat may be configured to fold upwardly or towards the back support, so that a relatively large space must exist between the back support and the seat so that the seat may fold into that space. That space is usually located where a user requires back support.

It also is desirable that the folding chair be durable. It will be appreciated that the chair will be stored and used, folded and unfolded, innumerable times. Similarly, it is desirable that the folding chair be strong. The chair must be able to support persons of various weight, and also potentially abusive conditions. It also is desirable that the folding chair be safe. It will be appreciated that as the various parts of the chair fold, there is a potential for fingers and the like to become pinched within the folding mechanisms. Therefore, it would be advantageous to develop a folding chair capable of folding for high density storage. It also would be advantageous to develop such a folding chair which is more stable and safe in the folded and stored position. It also would be advantageous to develop a folding chair which may easily be folded and unfolded. It also would be advantageous to develop a folding chair which is comfortable and safe. It also would be advantageous to develop a folding chair which is durable, strong, and cost effective.

OBJECTS AND SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a folding chair which folds relatively thin to maximize storage density.

It is another object of the present invention to provide such a folding chair which stores safely and is stable when stored, and/or stacked.

It is another object of the present invention to provide a folding chair which is easily folded and unfolded.

It is yet another object of the present invention to provide a folding chair which is safe and comfortable.

It is yet another object of the present invention to provide a folding chair which is durable, strong, and cost effective. STORABLE FOLDING CHAIR

The above objects and others not specifically recited are realized in a specific illustrative embodiment of a folding chair having a rigid support frame with a curved spline profile, and a seat and rear legs which fold into a closed position and substantially collapse within a volume defined by the support frame, such that the chair maximizes stacking density, and such that folded chairs have the curved spline profile to nest within one another and resist relative movement. The support frame has first and second rigid side support members, each with an upper back support portion and extending forwardly to form front leg portions. The back support portion and the front leg portions are integrally and rigidly connected to advantageously form a curved spline profile.

A seat is pivotally coupled to the support frame, or to and between the first and second support members. A majority of the seat advantageously collapses to a folded position within a volume defined between the first and second rigid side support members.

Rear legs are pivotally coupled to the support frame, or to the respective first and second support members. A majority of the rear legs advantageously collapse to a folded position within the volume defined by the support frame between the first and second rigid support members.

In the folded position, the chair is relatively thin, and is substantially contained within the support frame and the curved spline profile. Thus, a plurality of chairs advantageously are able to be stacked together with a very high density. In addition, the chairs have a substantially curved spline profile in the folded position. The first and second support members, the seat and the rear legs have a curved spline profile of substantially uniform thickness in the closed folded position. The curved spline profile forms a protrusion and a recess such that a protrusion of a first folding chair may nest with a recess of a second folding chair. Thus, a plurality of chairs advantageously are able to nest together for greater stability.

In accordance with one aspect of the present invention, the support frame and first and second support members preferably are shaped to form a composite curve with an s-shape. In accordance with another aspect of the present invention, the front leg portions and rear legs are curved. The rear legs advantageously have a radius of curvature smaller than a radius of curvature of the front leg portions. The smaller radius of curvature of the rear legs allows the rear legs to pivot substantially between the front leg portions in the closed folded position. In addition, a bottom portion of the rear legs advantageously extends beyond the volume defined by the rigid support frame when the chair is in a folded position. Thus, the bottom portion of the rear legs advantageously nests with the front leg portions of a second adjacent folding chair to resist lateral relative movement and increase stability of the stacked chairs. In accordance with another aspect of the present invention, front and rear cross support members couple together the respective front leg portions and the rear legs. At least the front cross support member has left and right channels for substantially receiving a section of a rigid support frame of a second folding chair to increase stability, and to allow the rear legs to further collapse within the volume of the frame. FOLDING MECHANISM The above objects and others not specifically recited are realized in a specific illustrative embodiment of a folding chair having a support frame with a back support portion and first and second side supports extending to form front leg members. A seat is pivotally coupled to the support frame, and configured to pivot downwardly with respect to the support frame to fold between the front leg members in a closed position.

First and second rear legs each including an upper member pivotally coupled to a lower member. The lower members are pivotally coupled to the support frame. The upper members are pivotally coupled to the seat and define linkage members. Thus, the rear legs include three pivot points and fold onto themselves to a shorter length in a closed position.

The support frame, the seat, and the first and second rear legs define respective first and second folding systems forming four-bar linkage systems. Each folding system has four pivot points and four linkages. The first linkages are defined by the first and second side supports of the support frame. The second linkages are defined by the lower members of the first and second rear legs. The third linkages are defined by the upper members of the first and second rear legs. Finally, the fourth linkages are defined by first and second sides of the seat. The four pivot points of the first and second folding systems advantageously fold substantially in-line. In addition, the folding systems fold onto themselves substantially within a volume defined by the support frame when the folding chair is in the closed folded position.

The folding systems advantageously include at least one stopper coupled to the four-bar linkage system, and shaped and positioned to engage at least one of the linkages when the folding chair is in the opened unfolded position to provide a limited opened position. In accordance with one aspect of the present invention, the stopper is formed on at least one of the upper members, and is shaped and positioned to engage at least one of the lower members of the first and second rear legs in the opened unfolded position. Preferably, the at least one stopper is formed on an extension from at least one of the upper members, and engages at least one of the lower members at a location substantially in line with the side supports such that the flanged stopper is shielded by the side support. FOLDING MECHANISM WITH KICK-OUT TAB

The above objects and others not specifically recited are realized in a specific illustrative embodiment of a folding chair having a four-bar linkage folding system with four pivot points and four linkages, and having a kick-out tab for urging the four-bar linkage system, and thus the chair, to unfold. The folding chair includes a support frame with a back support portion and first and second side supports extending to form first and second front legs. The support frame, or side supports, defines a first linkage of the four-bar linkage system.

First and second rear legs are pivotally coupled to the support frame at respective first and second pivot points. At least one of the rear legs extends upwards from the pivot point on the support frame to form an upper extension.

The upper extension defines a second linkage of the four-bar linkage system.

A linking member is pivotally coupled to and between the upper extension of the rear leg and the seat. The linking member defines a third linkage of the four-bar linkage system. A seat is pivotally coupled to the support frame. The seat has a seating surface and a seat frame. The seat, or a portion thereof, defines a fourth linkage of the four-bar linkage system.

The rear legs and seat pivot with respect to the support frame between an open unfolded position, and a closed folded position. Preferably, the seat and/or legs substantially collapse into a volume defined by the support frame. Similarly, the four-bar linkage system also pivots between open and closed positions. Preferably, the linkages of the four-bar linkage system fold together, into the volume defined by the support frame, and so that the pivot points of the four-bar linkage system are substantially in-line. The seat advantageously has at least one engagement surface which is engaged by the upper extension of the rear leg when the chair is in the closed folded position. Preferably, at least one kick-out tab is attached to the seat and has a surface forming the engagement surface. The engagement surface, or the kick-out tab, is shaped and positioned such that the upper extension of the at least one rear leg contacts the engagement surface, or the at least one kick-out tab, urging the seat in an outward direction during the initial stages of unfolding. Thus, the at least one rear leg forms a lever with the upper extension contacting the engagement surface of the seat and an opposite end contacting a floor to urge the seat from the closed folded position towards the open unfolded position. FLEXIBLE BACK SUPPORT AND LUMBAR SUPPORT

The above objects and others not specifically recited are realized in a specific illustrative embodiment of a folding chair having a flexible back support with a lumbar support member, and with a perimeter flange protruding from a front surface of the back support and extending across a front portion of a support frame. The support frame has a back support portion, front leg portions, and rear legs. A seat is pivotally coupled to the support frame. The flexible back support is coupled to the support frame. The back support is flexible and displaces in response to the user's weight.

In accordance with one aspect of the present invention, the back support has a lumbar support member extending down from the back support to reach a lumbar region of a user's back. The lumbar support member extends from the back support into a space between the back support and seat. The seat preferably pivots in a downward direction away from the back support, and the lumbar support member, such that the seat folds without interfering with the lumbar support member. In addition, the lumbar support member preferably has a horizontal concave curvature integrally formed with a vertical convex curvature to support a user's lumbar region, and to provide several comfortable seating positions. Thus, the lumbar support is unique to folding chairs.

In accordance with another aspect of the present invention, the flexible back support has a perimeter flange protruding from a front surface of the back support, and extending across a front portion of the support frame. The perimeter flange displaces across the front portion of the support frame in proportion to a load applied to the back support, thus allowing the back support to flex and conform to a user. The perimeter flange extends across a gap created between the flexible back support and the support frame. Thus, when a load is applied to the back support and the back support flexes, causing the gap to open, the perimeter flange conceals the gap as the flexible back support goes from a loaded position to an unloaded position. Therefore, the perimeter flange advantageously prevents pinching of articles of clothing or skin of a user.

INDEXING SEAT

The above objects and others not specifically recited are realized in a specific illustrative embodiment of a folding chair having a folding, stabilizing seat. The chair includes a support structure having a back support portion and leg supports. The stabilizing seat is pivotally coupled to the support structure.

The seat has a seating surface, and at least one upper projecting alignment member. The alignment member is configured to substantially engage a second chair to stabilize and prevent relative lateral movement between the two chairs when in a folded and stacked relationship. In accordance with one aspect of the present invention, the upper projecting alignment member protrudes from a rear corner of the seat. In addition, two upper projecting alignment members may each protrude from a rear corner of the seat.

In accordance with another aspect of the present invention, the upper projecting alignment member is integrally formed with the seating surface. The integral, upper projecting alignment member protrudes substantially perpendicular to the seat surface. The integral alignment member may include a seating curvature forming a continuous extension of the seating surface.

In accordance with another aspect of the present invention, a majority of the stabilizing seat collapses into a volume defined by the support structure with the upper projecting alignment member protruding therefrom to engage another chair. The upper projecting alignment member nests with the support structure of the second adjacent and stacked chair. INDEXING FEET The above objects and others not specifically recited are realized in a specific illustrative embodiment of a folding chair having at least one indexing foot to engage at least one leg support of an adjacent folding chair to resist relative movement between the chairs when in a folded and stacked position. The chair includes a support structure having a back support portion and leg supports including front and rear legs. A seat is pivotally coupled to the support structure, and pivots between an open unfolded position, and a closed folded position. The at least one indexing foot is coupled to at least one of the front or rear legs. The indexing foot is shaped and positioned to engage at least one leg support of an adjacent folding chair to resist relative movement between the chairs when in a folded and stacked position.

The indexing foot may included a first protrusion being sized and configured to engage a leg of an adjacent stacked chair to resist relative lateral movement. In addition, the indexing foot may include a second, opposite protrusion being sized and configured to abut a foot of an adjacent stacked chair to resist relative longitudinal movement.

The indexing foot may include a recess being sized and configured to receive a leg of an adjacent stacked chair to resist relative lateral movement. In addition, the indexing foot may include an opposite protrusion being sized and configured to abut a foot of an adjacent stacked chair to resist relative longitudinal movement.

Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by the practice of the invention without undue experimentation. The objects and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the invention will become apparent from a consideration of the subsequent detailed description presented in connection with the accompanying drawings in which: FIG. 1 is a perspective view of a folding chair in accordance with the present invention in a first open unfolded position;

FIG. 2 is a side view of the folding chair of FIG. 1; FIGs. 2b-2f are side views of other folding chairs in accordance with the present invention in the first open unfolded position;

FIG. 3 is a side view of the folding chair of FIG.1 in a second closed or folded position; FIG. 4 is a side view of a storable/stackable folding chair system in accordance with the present invention showing two folding chairs in the folded position which are disposed adjacent one another in a nesting or indexing relationship;

FIG. 5 is a perspective view of the folding chair of FIG. 1 shown in the closed, folded position;

FIG. 6 is a perspective view of the folding chair of FIG. 1 shown in an intermediate position;

FIG. 7 is a perspective view of the folding chair of FIG. 1 shown in an intermediate position; FIG. 8 is a rear view of the folding chair of FIG. 1 ;

FIG. 9 is a detailed side view of a folding system of the folding chair in accordance with the present invention;

FIG. 10 is a partial cross sectional view of a back support of the folding chair in accordance with the present invention; FIG. 11 is a partial cross sectional view of the storable/stackable folding chair system of the present invention showing two folding chairs in the folded position which are disposed adjacent one another in a nesting or indexing relationship;

FIG. 12 is a detailed side view of the storable/stackable folding chair system of the present invention showing bottom ends of two folding chairs in the folded position which are disposed adjacent one another in a nesting or indexing relationship; and

FIG. 13 is a perspective view of a front indexing foot of the folding chair in accordance with the present invention; and FIG. 14 is a perspective view of a rear indexing foot of the folding chair in accordance with the present invention. DETAD0ED DESCRD7TION

For the purposes of promoting an understanding of the principles in accordance with the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would normally occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention claimed.

STACKABLE/STORABLE THIN FOLDING CHAIR

As illustrated in FIG. 1, a folding chair, indicated at 10, in accordance with the present invention, is shown in a first, open, unfolded orientation or position. As indicated above, typical prior art chairs fold into a thick, awkward or bulky shape or configuration, or have significant protruding members, such that typical prior art folding chairs are less dense when stored, and require more space for storage. The folding chair 10 of the present invention utilizes a new approach in which the chair 10 is designed or configured to fold or collapse into a minimum thickness, such that the chairs 10 of the present invention have a very high storage density, while still providing strength, comfort, and durability. Thus, when folded, the chair 10 of the present invention advantageously is thin or presents a minimal profile, as shown in FIG. 3. In addition, the thin profile of the chair 10 advantageously is shaped or configured to facilitate nesting or indexing with adjacent chairs, as shown in FIG. 4. The shape of the thin profile of the chair of the present invention 10 may take various configurations. For example, the profile may be broadly convex, or broadly concave, as shown in FIGs. 2b and 2c, respectively. The broad single convex or concave curve is more cost effective to manufacture because it is easy to produce, and requires less expensive tooling. The convex curvature may provide greater structural integrity, while the concave profile may provide more comfortable sitting angles. Alternatively, the profile may be a composite curve with opposite curvatures forming an s-shape profile, as shown in FIGs. 2d and 2e. Such an s-shape profile may be less cost effective because it is more difficult to manufacture, and requires more expensive tooling. The s-shape profile, however, combines the structural rigidity of a convex curve and the more comfortable sitting angles of the concave curvature. In addition, the profile may have relatively straight ends, and a composite curve with an s-shape formed between the two straight ends, as shown in FIG. 3.

It will be appreciated that the curved profiles as shown and described above are merely a few examples of the numerous curved configurations which may be available. In addition, there are innumerable straight spline profiles which may be available, as shown in FIG. 2f. The curved or straight profiles provide the advantage of nesting or mating with adjacent profiles when the chairs are in a folded position for storage. All of the embodiments advantageously comprise elements which fold or collapse within a volume defined by the thin profile itself, thus resulting in a very dense stacking arrangement. Referring to FIGs. 1 and 2, the folding chair 10 has a rigid support frame

14 including left and right, or first and second, rigid side supports 18 and 20, as shown in FIG. 1. As indicated above, it is desirable that the chair 10 be durable and strong. Thus, the rigid nature of the support frame 14 increases the durabihty and strength of the chair 10. Preferably, the support frame 14 is formed from a tubular material to optimize strength and weight. In addition, the tubular material preferably has an elongated cross-sectional shape which is oriented generally vertically to increase the weight capacity of the chair 10. Furthermore, the tubular material preferably has rounded corners, or most preferably has an oval cross-sectional shape, giving soft edges to the frame 14 which are more comfortable as shown in FIGs. 10 and

11.

The support frame 14, and side supports 18 and 20, have an upper back support portion 24 forming the back of the chair 10, and a lower front leg portion 28 formed integrally and continuously with the upper back support portion 24. The back support portion 24 extends forwardly from the back of the chair 10 to the lower front leg portions 28. Thus, the first and second side supports 18 and 20, or the upper and lower portions 24 and 28 thereof, are unitary, integral and rigid structures to increase strength and durabihty. The front leg portion 28 preferably includes left and right, or first and second, front legs 32 and 34. In addition, the support frame 14, or side supports 18 and 20, may be a single integral member with a broad curved back member 36 formed at the tops of the side supports 18 and 20, as shown.

As indicated above, the rigid support frame 14 preferably is shaped to form a curved spline profile. As used herein, the term "curved spline" is used broadly to describe an elongated member with at least a curved portion, and which may include multiple curves and/or straight portions as well. For example, the curved spline may be a single continuous curve such as the broadly convex or concave curves shown in FIGs. 2b and 2c. As another example, the curved spline may be a compound curve including two oppositely curved portions joined end to end to form an s-shape, as shown in FIGs. 2d and 2e. As a further example, the curved spline may include two oppositely curved portions 31 and 33 joined end to end to form an s-shape, as shown in FIG. 3. The curved spline may further include straight end portion 35 and straight or curved end portion 37 coupled there between by a compound curve, as shown in FIG. 3. The profile is an elongated continuous profile having a substantially uniform thickness which is relatively thin when all elements are collapsed within the profile. The thin uniform profile contributes to a higher storage density of the chairs.

The chair 10 also includes a rear leg portion 38, which preferably includes left and right, or first and second, rear legs 40 and 42, as shown in FIG. 1. The rear leg portion 38, or rear legs 40 and 42, are pivotally coupled to the support frame 14 at leg pivot points 46. The leg pivot points 46 are preferably fixed pivot points, such that the rear legs 40 and 42 pivot with respect to the support frame

14 or front legs 32 and 34.

In addition, the chair 10 includes a seat or seat portion 50 pivotally coupled to the support frame 14, and between the side supports 18 and 20 at seat pivot points 54. Again, the seat pivot points 54 are preferably fixed pivot points such that the seat 50 pivots with respect to the support frame 14, rather than sliding. The seat 50 and rear legs 40 and 42 also are pivotally connected as discussed in greater detail below. The seat 50 may comprise a seating surface 51 secured to a seat frame 52. The seat frame 52 may extend generally around the perimeter of the seat 50, or along the sides, front and back of the seat 50. This provides an advantage where the seat may flex in response to a load, as discussed below. The seating surface 51 is disposed on the seat frame 52, and spans the distance between the perimeter of the frame 52. Preferably, the seating surface 51 is formed of a flexible material, and flexes, bends, or deflects downwardly and into the seat frame 52 in response to, and proportional to, a user's weight. The flexibility of the seating surface 51 is enabled because of the perimeter location of the seat frame 52, and allows the seating surface 51 to cup or curve, and thus conform to the user for a custom fit.

In addition, the seating surface 51 preferably is coupled to the seat frame 52 only at the front and back, and not at the sides, to further allow the seat surface 51 to deflect.

The seat 50 and rear legs 40 and 42 pivot with respect to the support frame 14 between (1) the first, open, unfolded position, as shown in FIGs. 1 and

2, and (2) the second, closed, folded position, as shown in FIG. 3. The leg pivot points 46 preferably are located on a straight section of the support frame 14, or first and second side supports 18 and 20, or at a mid-section of the composite curve. Thus, holes for the pivot point 46 may be formed in the side supports 18 and 20 prior to bending the support frame 14 during the manufacturing process.

If the holes are located on curved portions of the support frame 14, then forming the holes prior to bending may cause the holes to be mis-shaped as the curve portion of the support frame is formed.

The location of leg pivot points 46 facilitates a chair having a curved spline. By locating the pivot point 46 at the mid-section of a composite curve, or at the intersection of two linear members, the relative shear and load stresses (combined stresses), as well as the strain, in the frame 14 are at a minimum. The stress is high at the leg pivot points 46 because the rear legs 40 and 42 act as lever arms to concentrate the force. Referring to FIG. 3, the seat 50 and rear legs 40 and 42 advantageously pivot such that a majority of the seat 50 and a majority of the rear legs 40 and 42 collapse within a volume defined by the support frame 14. Thus, in the folded position, the chair 10 substantially maintains the curved spline profile of the support frame 14. The chair 10 (or the support frame 14, seat 50 and rear legs 40 and 42) also advantageously has a curved spline profile in the closed position, with the profile having a substantially uniform thickness which is relatively thin. The volume defined by the support frame 14 is the space between the side supports 18 and 20. Thus, the seat 50 and rear legs 40 and 42 pivot such that a majority of the seat 50 and rear legs 40 and 42 fold directly between the side supports 18 and 20.

The seat 50 and rear legs 40 and 42 collapsing within the volume of the frame 14 provides a distinct advantage over prior art folding chairs, in which the seat and legs fold inwardly and onto the frame such that the frame, legs and seat form a relatively thick stack. In addition, the curved spline profile of the chair 10 in the folded position provides a distinct advantage over the prior art chairs, in which the profiles are straight and/or bulky. The chairs 10 of the present invention are capable of not only folding into a relatively thin profile in order to save storage space, but also forming a continuously and similarly shaped profile in which the profiles of adjacent chairs may be matched or nested to increase stability of the chairs in a stacked and stored relationship.

As illustrated in FIG. 4, a storable folding chair system, indicated generally at 60, may include a plurality of the above described chairs, including, for example, a first chair 10 and a second chair 62. The curved spline profile of the first folded chair 10 nests or indexes with the curved spline profile of the second folded chair 62 to resist relative motion of the two chairs 10 and 62 when disposed adjacent one another in an adjacent storage relationship. Referring again to FIG. 3, the curvature of the profile creates a protrusion or protruding portion 66 of the profile and an opposite matching indentation or recess 68 in the profile as the profile deviates from a straight line into a curvature. Thus, referring to FIG. 4, the protrusion 66 of the profile of the first chair 10 nests or indexes within the indentation or recess 68 of the profile of the second chair 62. Unlike many prior art folding chairs, which include a backrest portion which protrudes from the straight thick profile of the chair into the straight thick profile of an adjacent chair, the entire profile of the chair 10 of the present invention simultaneously forms the protrusions 66 and indentations 68 such that it is the entire profile of the chairs 10 and 62 which match to nest.

Referring again to FIGs. 1 and 2, the front legs 32 and 34 are preferably curved, and may be convex, as shown. The rear legs 40 and 42 are advantageously similarly curved so that the rear legs 40 and 42 may substantially collapse within the volume defined by the front legs 32 and 34. Both the front and rear legs 28 and 38 have a radius of curvature, with the radius of curvature 27 of the rear legs 40 and 42 being smaller than the radius of curvature 29 of the front legs 32 and 34. The smaller radius of curvature 27 of the rear legs 40 and 42 allows a greater portion of the rear legs 40 and 42 to collapse within the volume defined by the front legs 32 and 34.

Referring to FIG. 3, the smaller radius of curvature of the rear legs 40 and 42 also allows a portion of the bottom ends 72 of the rear legs 40 and 42 to protrude or extend outside the volume defined by the front legs 32 and 34. Although it is desirable to have a majority of the seat 50 and rear legs 40 and 42 collapse within the profile of the frame 14, the bottom ends 72 of the rear legs 40 and 42 extend outside of the volume of the front legs 32 and 34 to increase the stability of multiple stacked chairs. Referring to FIG. 4, it can be seen that the bottom ends 72 of the rear legs 42 of the first chair 10 protrude slightly from the profile, specifically of the front legs 34, of the first chair 10, and into the profile of the second chair 62. Therefore, the curved spline profile of the chairs 10 and 62 resists relative movement between the two chairs 10 and 62 in a longitudinal direction (or top to bottom direction), and the bottom end 72 of the first chair 10 protruding into the profile of the second chair 62 resists lateral relative motion (side-to-side) between the two chairs 10 and 62.

Referring again to FIG. 1, the chair 10 may further include front and rear cross support members 76 and 78. The front cross support member 76 is coupled to and between the front legs 32 and 34 near the bottoms thereof. Similarly, the rear cross support member 78 is coupled to and between the rear legs 40 and 42. It will be appreciated that the front cross support member 76 is located between the front legs 32 and 34 and within the volume defined by the front legs 32 and 34, and thus may interfere with the rear legs 40 and 42 as they collapse into the volume defined by the front legs 32 and 34. Therefore, the forward cross support member 76 is preferably located closer to a forward surface 82 of the support frame 14 or front legs 32 and 34 than a rearward surface 84. Positioning the front cross support member 76 closer to the forward surface 82 allows more room for the rear legs 40 and 42 to collapse into the volume defined by the front legs 32 and 34.

In addition, the front cross support member 76 may have left and right, or first and second, rear facing channels or indentations 88 and 90, formed at opposite ends thereof where the front cross support member 76 is attached to the front legs 32 and 34. Thus, as the rear legs 40 and 42 collapse within a volume defined by the front legs 32 and 34, the rear legs 40 and 42 are received within the first and second rear facing channels or indentations 88 and 90, respectively, so that the rear legs 40 and 42 are allowed to collapse further within the volume without being hindered by the front cross support member 76. Furthermore, the front cross support member 76 may include left and right, or first and second, forward facing channels or indentations 92 and 94. The forward facing channels 92 and 94 receive the rear legs of an adjacent second chair such that the two chairs may index or nest, with the rear legs of the second chair extending into the forward facing channels 92 and 94 and between the front legs 32 and 34 of the first chair.

FOLDING MECHANISM

Left and right, or first and second folding systems, represented by the second or right folding system 100, are formed by and pivotally couple the frame 14, seat 50 and respective first and second rear legs 40 and 42 together. The folding system 100 allows the various components of the chair 10 to fold as thinly as possible in the folded position, and provides strength to the seat in the open position.

The rear legs 40 and 42 are pivotally coupled to both the frame 14 and the seat 50. Referring again to FIGs. 1 and 2, the rear legs 40 and 42 include upper and lower members or portions 104 and 106 which are pivotally coupled together at pivot point 108. The upper and lower portions 104 and 106 of the rear legs 40 and 42 preferably are coupled in a side by side relationship. The pivotal coupling 108 between the upper and lower members 104 and 106 of the rear legs 40 and 42 allows the upper and lower portions 104 and 106 to pivot with respect to one another, and to fold onto themselves to a shorter length in the closed, folded position. The lower member 106 of the rear legs 40 and 42 is pivotally coupled to the support frame 14 at the leg pivot points 46. The upper members 104 of the rear legs 40 and 42 are pivotally coupled to the seat 50 at pivot point 110. Thus, the rear legs 40 and 42 include three pivot points 46, 108 and 110.

The folding systems 100 form four bar linkage systems with four pivot points and four linkages. A first linkage is formed by the support frame 14 or side support members 18 and 20. A second link is formed by the lower members 106 of the rear legs 40 and 42. A third linkage is formed by the upper members 104 of the rear legs 40 and 42. The upper member 104 forms a linkage member between the seat and lower member 106 of the legs 40 and 42. Finally, a fourth linkage is formed by the seat 50 or seat frame 52. Thus, the four bar linkage system includes four links 20, 52, 104 and 106, and four pivot points 46, 54, 108 and 110.

Referring to FIGs. 1 and 5, the side support members 18 and 20, or first linkage, preferably form the outside perimeter or outermost sides of the chair 10. The lower members 106 of the rear legs 40 and 42, or the second linkage, are disposed inside the side supports 18 and 20. The upper members 104 of the rear legs 40 and 42, or third linkage, are disposed inside the lower members 106. The seat 50 or seat frame 52, or fourth linkage, is disposed inside the upper members 104, and inside the side support members 18 and 20.

Therefore, as illustrated in FIG. 5, the four-bar linkage system may fold upon itself, and collapse into a volume of the support frame 14. In addition, the folding systems 100 fold substantially in line, as indicated by line 114 in FIG. 3.

Thus, all the linkages of the four bar linkage system, or the side support members 18 and 20, rear legs 40 and 42, and seat 50, fold substantially onto themselves, and substantially in line. Therefore, the configuration of the linkage systems 100 as four bar linkage systems allows the chair to fold into the thin profile in the folded position. In addition, pivotally coupling all linkages, including the rear legs, provides greater stabihty. When the chair 10 is in an open, unfolded position, as illustrated in FIGs. 1 and 2, the folding systems, or four bar linkage systems, are also in an open orientation. In the open orientation, the four bar linkage system forms an inverted triangular shape. When the chair is in the closed, folded, position as illustrated in FIGs. 3 and 5, the folding system 100 or four bar linkage system is also in a closed orientation. The inverted triangular configuration of the four bar linkage system provides greater stabihty. It is desirable to maximize the size of the inverted triangle to maximize the stabihty. For example, it is desirable to place the pivot point 110 of the rear legs 40 and 42 or upper members 104 and the seat 50 as forwardly as possible to increase stabihty and facilitate the tendency for the chair to open to a stable, locked position.

The stabihty of the chair 10 in the open position is a function of the pivot axis 110 because any weight put on the chair or seat 50 behind the forward most pivot point 110 pushes the chair into an open, locked and stable position. Although it is desirable to place the pivot point 110 as forwardly as possible in the seat 50, doing so decreases the angle between the rear legs 40 and 42 and the floor, thus decreasing the size of the inverted triangle, or causing the lower portion 72 of the rear legs 40 and 42 to extend further outward, thus causing a tripping hazard. Thus, it is important to balance several factors, including maintaining as large an angle in the rear legs 40 and 42 as possible for strength, without having the rear legs protrude too far, and maintaining a forward pivot point 110 as forwardly as possible for stabihty. The chair 10 also has a footprint defined by the width of the chair, and the location on the floor of the front and rear legs 32 and 34 and 40 and 42. It is of course desirable to have as large a footprint as possible for stabihty; however, it is also important to prevent the legs from sticking out too far and becoming a tripping hazard.

In the closed, folded orientation, as illustrated in FIG. 5, the folding systems 100, or four bar linkage systems, fold substantially onto themselves and substantially in line, and all of the pivot points 46, 54, 108 and 110 are substantially in line or lay substantially in a straight line. Because the pivot points

46, 54, 108 and 110 are in line in the folded position, the chair 10 is stable in the folded position and resists inadvertent unfolding, or will not unfold without assistance.

Referring to FIGs. 5-7, the chair 10 of the present invention is shown transitioning from the closed, folded position to a partially open position, or from a partially open position to the closed, folded position. The figures also illustrate the folding system 100, or four bar linkage systems, folding upon themselves and becoming substantially in-line. To open the chair, or transition the chair from the closed, folded position to the open, unfolded position, force is apphed to the front legs 32 and 34, through the front cross support member 76, as indicated by arrow 118. Alternatively, the force could be apphed to the back of seat 50. The apphed force 118 causes the seat 50 to pivot away from the support frame 14 which causes the rear legs 40 and 42 also to pivot outwardly away from the frame 14. Thus, the apphed force 118 causes the folding system 100, or four bar linkage systems to move from their stable folded positions to a more open position. Once the folding systems 100, or four bar linkage systems, have been moved out of the stable, folded position, any additional force, such as a user sitting on the seat, or setting the chair 10 on the ground, tends to cause the folding system 100, or four bar linkage systems, to be forced into the fully open position. Therefore, the chairs 10 tend to be safer because any additional force tends to open the chair rather than fold the chair.

To open the chair, a person may set the chair on the ground with the bottom of the rear legs 72 contacting the ground while holding the top of the chair and applying the force 118 onto the front legs 32 and 34, such as by pushing on the front cross support member 76 with the person's foot. Alternatively, the chair may be opened by swinging the chair in a forward direction and impacting the bottom portion 72 of the rear legs on the ground, such that the momentum of the swinging chair causes the seat 50 and front legs 32 and 34 to continue in a forward motion, thus opening the chair. Therefore, the chairs 10 may be opened with one hand. In addition, the folding system 100 advantageously includes a stop or stopping member to limit movement of the folding system in the open position to prevent further movement. For example, the stop or stopping member may be attached to one of the links of the four bar linkage systems, and positioned to abut another one of the links in the open position to limit movement of the four bar linkage system at that point.

Referring to FIGs. 7 and 8, the upper portion or member 104 of the rear legs 40 and 42 has an extension 124 which extends beyond the pivot point 108 between the upper and lower members 104 and 106 of the rear legs 40 and 42, such that the extension 124 extends along or towards the lower member 106 of the rear legs 40 and 42. The extension 124 extends linearly from the upper member 104 such that the extension 124 extends alongside the lower member 106 in the open position. The stopper is preferably a flange 128 formed on the extension 124 of the upper portion 104 of the rear legs 40 and 42. Thus, as the four bar linkage systems unfold into the open, unfolded position, the upper and lower members 104 and 106 of the rear legs 40 and 42 ahgn, and the flange 128 of the extension 124 abuts the lower portions 106 of the rear legs 40 and 42, limiting further movement.

The extension 124 of the upper member 104 of the rear legs 40 and 42 advantageously is sized to extend alongside the support frame 14 or alongside the side supports 18 and 20 in either or both of the open and closed positions. Therefore, the frame 14 or side supports 18 and 20 act as a shield to shield the stopper or flange 128, substantially impeding unintentional insertion of a hand or finger or the like between the flange 128 and the lower member 106 of the rear legs 40 and 42, to prevent a person from being inadvertently pinched by the flange 128.

It is of course understood that a stopper may be formed on any of the links and shaped or configured to abut any of the other links.

To fold the chair, or transition the chair from the open, unfolded position to the closed, folded position, a user may place his or her foot on the rear cross support member 78 and pull upwardly on the support frame 14, causing the chair to move into the closed, folded position. Alternatively, the user may lift the chair and swing it rearwardly, and impact the lower portion 72 of the rear legs 40 and

42 on the ground, such that the momentum of the swinging chair 50 causes the seat 50 and front legs 32 and 34 to continue to move rearwardly into the folded position. Therefore, the chairs 10 may also be closed using one hand.

Referring to FIGs. 5-7, the seat frame 52 has a notched corner 132, or a notch formed in the back corners of the seat, for receiving the flange 128 therein when the chair is in the closed, folded position. Because the folding systems, or four bar linkage systems, substantially fold onto themselves, the upper portions 104 of the rear legs 40 and 42 fold adjacent the seat frame 52 in the closed position. The notched corner 132 allows room for the flange 128 and allows the upper members 104 of the rear legs 40 and 42 to fold adjacent and in-line with the seat frame 52.

KICK-OUT TAB

As indicated above, when the chair 10 is in the folded orientation, and thus when the folding systems 100 are in the closed position, the pivot points 46, 54, 108 and 100 are substantially in-line. Because the pivot points are substantially in- line, the links or folding systems 100 are in equilibrium, or in a stable position.

Thus, the links or folding systems 100 generally have a tendency to pivot in either direction. Although the configuration of the various members such as the seat 50 and the legs typically prevents the folding system 100 or links from pivoting in the wrong direction, or further into the chair, it may be difficult to unfold the seat because the pivot points are in-line.

Referring to FIG. 7, the lower members 106 of the rear legs 40 and 42 have an upper extension 140 extending upwardly past the pivot point 108 towards the seat 50. Preferably, a kick-out tab 144 is attached to the seat frame 52, and has an engagement or operating surface 148. The kick-out tab, and thus the engagement surface 148, is sized and located on the support frame 52 to engage the upper extension 140 of the lower member 106 of the rear legs 40 and 42 in the closed orientation, or during the transition from the closed to the open orientations.

Referring to FIG. 9, the upper extension 140 of the lower member 106 abuts the operating surface 148 of the kick-out tab 144 in the closed orientation.

As the chair is opened, the rear legs 40 and 42 pivot outwardly away from the chair, causing the upper extension 140 of the rear legs 40 and 42 to pivot forwardly towards the seat 52. The upper extension 140 bears against the engagement surface 148, and tracks along the engagement surface, to force the seat 50 outwardly. Thus, the rear legs 40 and 42 act as a lever arm, forcing the upper extension 140 against the kick-out tab 144, and urging the seat 50 in the proper direction. Therefore, the upper extension 140 and kick-out tab 144 help urge the folding system 100 in the correct direction to open the chair. The kick- out tab 144 may be a flange-like member coupled to the frame 52 for durabihty. Alternatively, an underside of the seat 50 may form the operating surface against which the upper extension 140 abuts. The upper extension 140 of the rear legs 40 and 42 tracks along the engaging surface or ghde surface 148 of the kick-out tab 144. The kick-out tab 144 and upper extension 140 of the rear legs 40 and 42 is one example of an urging means for urging the seat 50 from the folded orientation, and for facilitating unfolding of the folding system 100. The kick-out tab 144 and upper extension 140 of the rear legs 40 and 42 allow the four bar linkage system to open, and thus allow the chair to unfold without the folding system 100 or four bar linkage system locking up, or pivoting in the wrong direction. BACK SUPPORT Referring again to FIG. 1 , the chair 10 has a back support 156 coupled to the upper back support portion 24 of the support frame 14, and/or coupled to and between the side supports 18 and 20. The back support 156 is supported between the side supports 18 and 20, or the rigid frame 14. The back support 156 advantageously is flexible and bends or flexes inwardly or rearwardly as force is apphed, such as when a person leans back against the back support 156. Thus, the back support 156 displaces or bends rearwardly in response to an amount of weight or force apphed thereon, to provide an automatic response or adjustment, and to be more comfortable. Thus, the back support is self adjusting. The flexible back is a significant improvement over prior art folding chairs which have rigid metal backs, or inflexible backs.

In addition, the back support 156 advantageously includes a lower lumbar region 160 which extends downwardly from the back support 156 to a lumbar region of a user's back. The lower lumbar region 160 of the back support 156 is a significant advantage over prior art seats. As indicated above, many typical prior art seats have a relatively small space between the seat and the back because the seat folds upward into the space below the back support. Thus, the back support of many prior art chairs tends to be a thin, high portion which only supports the upper region of a user's back, not the lumbar region. Because the seat 50 of the present invention folds downwardly, the lumbar support member 160 is able to extend downwardly without interfering with the folding motion of the seat 50. The lumbar support member or protrusion 160 is secured to the support frame 14 only through the back support 156, without being directly attached to the support frame 14, or side supports 18 and 20. Preferably, the lumbar support member 160 is integrally formed with the back support 156 and is similarly flexible so that the lower lumbar member may flex or move with respect to the back support 156 and with respect to the support frame 14. Therefore, not only does the entire back support 156 displace rearwardly in response to the user's weight, but the lower lumbar support member 160 itself displaces rearwardly with respect to the back support 156 to further provide a cushioning response to the user's lumbar region.

The back support 156 preferably is shaped to have a horizontally concave curvature 157 integrally formed with a vertically concave curvature 159. The lumbar support member 160 advantageously has a horizontally concave curvature 161 integrally formed with a vertical convex curvature 162 to provide support for the user's lumbar region. The lumbar support member 160 also may have a reduced cross sectional area for providing greater flexibility with respect to the back support 156. The concave and convex contour, along with the flexibility, allows for comfortable seating in both an upright, and a relaxed position of the user.

Referring to FIG. 10, the support frame 14 has an inner surface 170 which faces into the volume defined by the frame 14, and a forward facing surface 172. The back support 156 extends between the inner surface 170 on the support frame, and across the forward facing surface 172 of the support frame 14, as described in greater detail below. The back support 156 has a rear flange 176 or protrusion extending from the back of the back support 156 rearwardly into the volume defined by the support frame 14. The rearward flange 176 is formed generally near the perimeter of the back support 156, and around at least a portion thereof, such that the rearward flange 176 also extends along a portion of the support frame 14 on either side, or along the side supports 18 and 20. Thus, the rearward flange 176 extends along the inner surface 170 of the support frame 14 on both sides. The back support 156 is attached to the support frame 14 by fasteners 180, such as rivets, which couple the rearward flange 178 to the inside or inner surface 170 of the support frame 14. Attaching the back support to the inner surface 170 of the support frame 14 allows the back support 156 to displace under a force, such as the user's weight.

The back support 156 advantageously also includes a perimeter flange 184 formed about at least a perimeter of the back support 156, and protruding or extending across a portion of the forward facing surface 172 of the support frame 14. The perimeter flange 184 advantageously extends over the gap or space formed between the back support 156, or rearward flange 176, and the support frame 14. As the back support 156 deflects rearwardly, the gap between the back support 156 and support frame 14 increases. The perimeter flange 184 advantageously displaces across the forward facing surface 172 of the support frame 14 as the back support 156 flexes rearwardly, allowing the back support

156 to flex while continuing to cover and conceal the gap. Thus, as the back support 156 returns to an unflexed position, the perimeter flange 184 prevents the back support 156 and support frame 14 from pinching any articles of clothing or skin which might otherwise have entered the gap. Referring again to FIG. 1 , the chair 10 may also have a handle 188 for a user to grasp the chair. As indicated above, the support frame 14, and thus the side supports 18 and 20, may be formed by a single integral member as shown. Thus, the handle 188 may be formed by the support frame itself at the top of the chair. Otherwise, additional support structures extending from the side supports 18 and 20 form the handle. In addition, an indentation 190 may be formed at the top of the back support member 156 such that a cavity or gap is formed between the top of the back support member 156 and the top of the support frame 14 for a user's fingers to extend through as the user grasps the handle 188.

As indicated above, the seat surface 51 may also be flexible and suspended between a perimeter seat frame 52. Thus, the seat surface 51 also deflects in response to a user's weight, and to cup or curve, and thus conform to the user for a custom fit. Therefore, the flexible seat 50 and back support 156 combine to provide a chair 10 which is both comfortable and foldable. INDEXING SEAT

As described above and illustrated in FIG. 4, the stackable/storable folding chair system 60 of the present invention includes a plurality of folding chairs 10 and 62 of similar geometry with profiles that nest to prevent relative movement in at least one direction. Referring to FIGs. 1 and 8, the folding chair 10 has an upward projecting alignment member 200 associated with the seat 50 or seat surface 51. The alignment members 200 preferably are formed in the rear corners of the seat surface 51 , and extend or protrude generally perpendicular to the seat surface 51. Referring to FIG. 8, the seat surface 51 and seat structure 52 may be broadly concave for a comfortable contour. The alignment members 200 may be formed flush with the upward surface of the seat surface 51, and continue the concave curvature of the seat surface 51 to project upwardly at the sides of the seat 50 and at the back. Thus, the curvature of the alignment members also adds to the contour and comfort of the seat 50.

Referring now to FIG. 11, the alignment member 200 is shaped, sized and located to substantially engage an adjacent stacked chair 62 to stabilize the chairs 10 and 62 relative to one another, and to resist relative lateral movement between the two chairs 10 and 62. Thus, although the seat 50 substantially collapses within the volume defined by the frame 14, the alignment members 200 protrude or project upwardly from the volume defined by the first chair 10 to extend into the volume defined by the support frame 14 of the second chair 62, and for engaging the support frame of the second chair. Thus, the alignment members 200 provide the dual purpose of adding to the comfortable contour of the seat surface 51, and stabilizing adjacent stacked chairs. In addition, while the profile of the chairs 10 and 62 resist longitudinal, or up and down, relative motion between the chairs, and the projecting lower end 72 of the rear legs 40 and 42 resist lateral, or left and right, relative motion, the ahgnment members 200 of the seat 50 further resist lateral, or side to side, relative movement of the chairs 10 and 62 near a mid-section of the chairs. Thus, the lower protruding end 72 of the rear legs 40 and 42 and the ahgnment members 200 of the seat 50 combine to create multiple points of stabihty along the adjacent stacked chairs. Alone, the protruding lower portion 72 of the rear legs 40 and 42 resist lateral relative motion at the bottom of the adjacent stacked chairs, while the tops may tend to displace laterally, resulting in a pivotal or rotational movement between the chairs. Similarly, the ahgnment members 200 of the seat 50 prevent lateral relative movement at a mid-section of the chairs alone, although the upper and lower ends may tend to move, resulting in a pivotal or rotational movement. Thus, the protruding lower end 72 of the rear legs 40 and 42 and the ahgnment members 200 of the seat 50 together resist both lateral and rotational movement.

INDEXING FEET

Referring again to FIG. 1, a chair 10 advantageously has indexing feet that attach to the bottom ends of the front legs 32 and 34 and rear legs 40 and 42. The indexing feet may include front indexing feet 210 and rear indexing feet 214. The indexing feet 210 and 214 have broad bottom surfaces 218 and 220 respectively for engaging a support surface, such as the ground. The feet 210 and 214 are preferably formed of rubber or a rubber-like material, so that the feet 210 and 214 frictionally engage the support surface and prevent relative displacement. In addition, the bottom surfaces 218 and 220 of the feet 210 and 214 may be contoured with protrusions and/or indentations to further effectuate frictional contact with the support surface.

Referring to FIG. 12, the indexing feet 210 and 214 further are configured to facilitate the stabihty of adjacent stacked chairs and resist relative movement. Thus, the indexing feet 210 and 214 are configured to engage adjacent chairs and/or the feet of adjacent chairs.

Referring to FIG. 13, the front indexing feet 210 have a toe 222 and a heel 234, and an insert 212 for inserting into the front legs 28 and 32. The front indexing feet also have a receiving portion 224 at the heel 234. The receiving portion 224 includes a concave recess 226 which receives the front leg of an adjacent stacked chair. The receiving portion 224 also includes a protrusion 228 at the heel 236 which extends alongside the front leg of an adjacent stacked chair to prevent lateral movement. The front indexing feet 210 also include an opposite protrusion 232 at the toe 222 which extends therefrom proximal to the bottom surface 218 of an adjacent front indexing foot 210 to resist longitudinal movement.

Referring to FIG. 14, the rear indexing feet 214 similarly have a toe 230 and a heel 236, and an insert 216 for inserting into the rear legs 40 and 42. The rear indexing feet also include a receiving portion 238 at the heel 236. The receiving portion 238 includes a concave recess 240 which receives the rear legs of an adjacent stacked chair. In addition, the receiving portion 238 includes a protrusion 242 which extends alongside the rear leg of an adjacent stacked chairs to resist lateral relative movement. In addition, the rear indexing feet 214 include an opposite protrusion 246 at the toe 230 which extends proximal to the bottom surface 220 of an adjacent rear indexing foot 214 to resist longitudinal movement.

Thus, referring to FIGs. 12-14, both the front and rear indexing feet 210 and 214 have opposite ends or sides, one side which resists lateral movement, and the other side resisting longitudinal movement. One end of the front and back indexing feet 210 and 214 has a projection which extends alongside the opposing legs of an adjacent stacked chair, while the other end has a projection which extends proximal the bottom end of the opposing legs or feet of an adjacent stacked chair. The longitudinal movement resisting projection 232 of the front feet 210 extends forwardly, while the longitudinal movement resisting projection

246 of the rear feet 214 extends rearwardly. Likewise, the lateral motion resisting protrusion 226 of the front feet 210 extends rearwardly, while the lateral motion resisting protrusion 242 of the rear feet 214 extends forwardly.

While the profiles of the adjacent stacked chairs are shaped to resist longitudinal movement, and the bottom portion 72 of the rear legs 40 and 42 engage adjacent stacked chairs to resist lateral movement, the indexing feet 210 and 214 further facilitate the stability of the chairs and resist relative movement. It is to be understood that the above-described arrangements are only iUustrative of the apphcation of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention and the appended claims are intended to cover such modifications and arrangements.

Thus, while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use may be made without departing from the principles and concepts set forth herein.

Claims

CLAIMSWhat is claimed is:

1. A folding chair comprising: a rigid support frame having an upper back support portion and extending forwardly to form integral lower front leg portions, the rigid support frame shaped to form a curved spline profile; rear legs pivotally coupled to the rigid support frame; and a seat pivotally coupled to the rigid support frame, the seat and the rear legs pivoting with respect to the rigid support frame between an open unfolded position, and a closed folded position, a majority of the seat and a majority of the rear legs collapsing within a volume defined by the rigid support frame.

2. The folding chair of claim 1, wherein the rigid support frame is shaped to form a composite curve.

3. The folding chair of claim 2, wherein the composite curve is s-shaped.

4. The folding chair of claim 1, further comprising: first and second folding systems pivotally coupling respective first and second rear legs, the rigid frame, and the seat together, such that the folding chair may fold from an opened to a closed position.

5. The folding chair of claim 1, wherein the rigid support frame further comprises first and second side supports each having upper and lower portions integrally connected at opposite ends of a curved portion.

6. The folding chair of claim 5, wherein the upper portion includes a linear portion integraUy connected with a concave portion, and the lower portion includes a linear portion integraUy connected with a convex portion, wherein the concave portion converges with the convex portion at a point substantiaUy within a mid-section of each of the first and second side supports forming a composite curve.

7. The folding chair of claim 6, wherein the seat is pivotaUy coupled at a pivot point, and wherein the pivot point is located at the mid-section of the composite curve.

8. The folding chair of claim 1, wherein the upper back support portion is substantiaUy concave, and the lower front leg portions are substantiaUy convex.

9. The folding chair of claim 1, wherein the front leg portions and rear legs are curved; wherein the rear legs have a radius of curvature smaUer than a radius of curvature of the front leg portions; and wherein the rear legs pivot substantiaUy between the front leg portions in the closed folded position such that the upper back support portion, the front leg portions, and the rear legs define a curved spline profile.

10. The folding chair of claim 1, wherein a bottom portion of the rear legs extends beyond the volume defined by the rigid support frame when the chair is in a folded position, such that the bottom portion of the rear legs nest with front leg portions of a second adjacent folding chair.

11. The folding chair of claim 1 , further comprising: front and rear cross support members to respectively couple together the front leg portions and the rear legs; and wherein the front and rear cross support members have left and right channels for substantiaUy receiving a section of a rigid support frame of a second folding chair.

12. The folding chair of claim 1 , wherein the seat is pivotaUy coupled to the support frame at a rearward location of the seat such that substantiaUy aU of the seat folds in a downward direction when moved toward the folded position.

13. The folding chair of claim 1, wherein the curved spline profile forms a protrusion and a recess such that a protrusion of a first folding chair may nest with a recess of a second folding chair.

14. The folding chair of claim 1, wherein the support frame, the seat and the rear legs have a curved spline profile of substantiaUy uniform thickness in the closed folded position.

15. A folding chair comprising : an upper back support portion and associated seat member; a lower front leg portion integraUy connected to the upper back support portion to form a curved spline profile, the upper back support portion and the lower front leg portion forming a rigid support frame; and rear leg portions pivotaUy coupled to the support frame, a majority of the rear leg portions coUapsing within a volume defined by the support frame.

16. A folding chair comprising: a support frame including first and second rigid side supports having back support portions and extending forwardly to form front leg portions, the support frame shaped to form a curved spline profile; rear leg portions pivotaUy coupled to the support frame; a back support coupled to the back support portions of the support frame; and a seat pivotaUy coupled to the first and second rigid side supports of the support frame; the support frame, the seat, and the rear leg portions being pivotaUy coupled together and pivoting relative to one another between: an opened position; and a closed position wherein a majority of the rear leg portions and a majority of the seat fold substantiaUy within a volume defined between the first and second rigid side supports to form a curved spline profile.

17. A folding chair comprising: a first rigid support member having an upper back support portion and a first front leg, the back support portion and the first front leg being integraUy and rigidly connected to form a curved spline profile; a second rigid support member having an upper back support portion and a second front leg, the back support portion and the second front leg being integraUy and rigidly connected to from a curved spline profile; a seat pivotaUy coupled to and between the first and second support members, a majority of the seat coUapsing to a folded position within a volume defined between the first and second rigid side support members; a back support coupled to and between the back support portions of the first and second support members; and first and second rear legs, pivotaUy coupled to the first and second support members, respectively, a majority of the first and second rear legs coUapsing to a folded position within the volume defined between the first and second rigid support members.

18. A storable folding chair system comprising: a first folding chair having a curved spline profile in a folded position; and a second folding chair having a curved spline profile in a folded position wherein the curved spline profiles of the folding chairs substantiaUy nest to resist relative motion in a stacked relationship.

19. The system of claim 18, wherein the first and second curved spline profiles have a composite curve.

20. The system of claim 18, wherein the curved spline profiles are s-shaped.

21. The system of claim 18, wherein the first and second folding chairs have matched indexing profiles which prevent the first and second folding chairs from sliding relative to one another in at least one direction.

22. The system of claim 18, wherein the curved spline profiles of the first and second chairs form protrusions and recessions such that a protrusion in the first chair is received within a recess of the second chair, and a protrusion of the second chair is received in a recess of the first chair.

23. The system of claim 18, wherein the folding chairs have a curved spline profile of substantiaUy uniform thickness in the folded position.

24. A folding chair comprising: a support frame having a back support portion and first and second side supports extending to form front leg members; a seat, pivotaUy coupled to the support frame, and configured to pivot downwardly with respect to the support frame and folding between the front leg members in a closed position; and first and second rear legs each including an upper member pivotaUy coupled to a lower member, the lower members being pivotaUy coupled to the support frame, and the upper members being pivotaUy coupled to the seat, such that the first and second rear legs include three pivot points and the rear legs fold onto themselves to a shorter length in a closed position.

25. The folding chair of claim 24, wherein the support frame, the seat, and the first and second rear legs define respective first and second folding systems forming four-bar linkage systems each having four pivot points and four linkages for folding the chair between an opened unfolded position and a closed folded position.

26. The folding chair of claim 25, wherein the four pivot points of the first and second folding systems fold substantiaUy in-line, and wherein the first and second folding systems fold onto themselves substantiaUy within a volume defined by the support frame when the folding chair is in the closed folded position.

27. The folding chair of claim 25, wherein first linkages of the four-bar linkage systems are defined by the first and second side supports of the support frame; the second linkages of the four-bar linkage system are defined by the lower members of the first and second rear legs; the third linkages of the four-bar linkage system are defined by the upper members of the first and second rear legs; and the fourth linkages of the four-bar linkage system are defined by first and second sides of the seat.

28. The folding chair of claim 25, wherein the four-bar linkage system includes at least one flanged stopper coupled to the four-bar linkage system and shaped and positioned to engage at least one of the lower members of the first and second rear legs when the folding chair is in the opened unfolded position to provide a limited opened position.

29. The folding chair of claim 24, wherein at least one of the upper members includes a flanged stopper shaped and positioned to engage at least one of the lower members of the first and second rear legs in the opened unfolded position.

30. The folding chair of claim 29, wherein the at least one flanged stopper is formed on an extension from at least one of the upper members and engages at least one of the lower members at a location substantiaUy in line with the side supports such that the flanged stopper is shielded by the side support.

31. The folding chair of claim 29, wherein the seat further comprises a seat frame and a seating surface, the seat frame also having at least one notched corner for receiving the at least one flanged stopper when the folding chair is in the closed folded position.

32. The folding chair of claim 24, wherein the rear legs fold substantiaUy within the support frame when the folding chair is in the closed folded position.

33. The folding chair of claim 24, wherein the upper member folds substantiaUy towards a rear portion of the seat.

34. The folding chair of claim 24, wherein the first and second folding systems are comprised of four-bar linkage systems forming inverted triangular support structures when the folding chair is in the opened position.

35. A folding chair comprising: a support frame having a back support portion and first and second side supports extending to form first and second front legs; first and second rear legs pivotaUy coupled to the support frame; a seat pivotaUy coupled to the support frame; first and second folding systems linking the support frame, the fold- down seat, and the rear legs together, the first and second folding systems including a four-bar linkage system with four pivot points and four linkages; and at least one stopping member coupled to the four-bar linkage system shaped and positioned to engage at least one of the linkages of the folding system in an opened unfolded position to provide a limited opened position.

36. The folding chair of claim 35, wherein the four pivot points of the first and second folding systems fold substantiaUy in-line, and wherein the first and second folding systems fold onto themselves substantiaUy within a volume defined by the support frame when the folding chair is in the closed folded position.

37. The folding chair of claim 35, wherein the rear legs each include an upper member pivotaUy coupled to a lower member, the lower members being pivotaUy coupled to the support frame, and the upper members being pivotaUy coupled to the seat.

38. The folding chair of claim 37, wherein the at least one stopper member is formed on an extension from at least one of the upper members and engages at least one of the lower members at a location substantiaUy in line with the side supports such that the flanged stopper is shielded by the side support.

39. The folding chair of claim 37, wherein first linkages of the four-bar linkage systems are defined by the first and second side supports of the support frame; the second linkages of the four-bar linkage system are defined by the lower members of the first and second rear legs; the third linkages of the four-bar linkage system are defined by the upper members of the first and second rear legs; and the fourth linkages of the four-bar linkage system are defined by first and second sides of the seat.

40. The folding chair of claim 37, wherein the stopping member is formed on at least one of the upper members and positioned to engage at least one of the lower members of the first and second rear legs in the opened unfolded position.

41. The folding chair of claim 35, wherein the seat further comprises a seat frame and a seating surface, the seat frame also having at least one notched comer for receiving the at least one stopping member when the folding chair is in the closed folded position.

42. The folding chair of claim 35, wherein the rear legs fold substantiaUy within the support frame when the folding chair is in the closed folded position.

43. The folding chair of claim 35, wherein the four-bar linkage systems form inverted triangular support structures when the folding chair is in the opened position.

44. A folding chair comprising: a support frame having a back support portion and first and second side supports extending to form first and second front legs; a seat pivotaUy coupled to the support frame; first and second rear legs pivotaUy coupled to the support frame; left and right linking members pivotaUy coupled to the seat and first and second rear legs respectively wherein the seat, the support frame, the first and second rear legs, and the left and right linking members define linkages of respective left and right four-bar linkages having four pivot points which pivot as the folding chair moves between a folded and an unfolded position; and at least one stopper attached to and protruding from one of the links shaped to engage another one of the links in the unfolded position to prevent further pivoting of the four-bar linkage and thus the folding chair.

45. A folding chair comprising: a support frame forming front leg portions; rear leg portions, pivotaUy coupled to the support frame at pivot points, with at least one of the rear leg portions extending upwards from the pivot point on the support frame to form an upper extension; and a seat, pivotaUy coupled to the support frame, and having an engagement surface, the seat and rear leg portions pivoting with respect to the support frame between an open unfolded position, and a closed folded position; and the upper extension of the at least one rear leg portion extending to engage the engagement surface of the seat in the closed folded position, the at least one rear leg portion forming a lever with the upper extension contacting the engagement surface of the seat and an opposite end for contacting a floor to urge the seat from the closed folded position towards the open unfolded position.

46. The folding chair of claim 45, further comprising: a kick-out tab attached to the seat and having a surface which forms the engagement surface.

47. The folding chair of claim 45, wherein the engagement surface is an elongated ghde surface, and wherein the upper extension of the at least one rear leg tracks along the ghde surface as the seat pivots from the closed folded position to the open unfolded position.

48. The folding chair of claim 45, further comprising: a folding system for folding the folding chair between the opened unfolded position, and the closed folded position, the folding system including a four-bar linkage system having four pivot points and four linkages.

49. The folding chair of claim 48, wherein the four pivot points of the first and second folding systems fold substantiaUy in-line.

50. The folding chair of claim 49, wherein the upper extension of the at least one rear leg portion bears against the engagement surface of the seat to facilitate unfolding of the folding system from a folded position where the pivot points are substantiaUy in-hne, such that the folding systems are urged to unfold in a proper direction.

51. The folding chair of claim 48, wherein a first linkage of the four-bar linkage system is a side support of the support frame; a second linkage of the four- bar linkage system is the upper extension of the rear leg; a third linkage of the four-bar linkage system is a link member pivotaUy coupled between the seat and the upper extension of the rear leg; and a fourth linkage of the four-bar linkage system is a side of the seat.

52. The folding chair of claim 51 , wherein the second, third and fourth linkages coUapse within a volume defined by the support frame.

53. A folding chair comprising: a support frame having a back support portion and first and second side supports extending to form first and second front legs; first and second rear legs, pivotaUy coupled to the support frame at first and second pivot points, respectively, with at least one of the rear legs extending upwards from the pivot points on the support frame to form an upper extension; a seat, pivotaUy coupled to the support frame, and having a seating surface and a seat frame; the seat and rear legs pivoting with respect to the support frame between an open unfolded position, and a closed folded position; at least one kick-out tab attached to the seat frame, the kick-out tab shaped and positioned such that the upper extension of the at least one rear leg contacts the at least one kick-out tab to urge the seat in an outward direction from the frame.

54. A folding chair comprising: a support frame having a back support portion and first and second side supports extending to form first and second front legs; first and second rear legs, pivotaUy coupled to the support frame at first and second pivot points, respectively, with at least one of the rear legs extending upwards from the pivot points on the support frame to form an upper extension; a seat, pivotaUy coupled to the support frame, the seat having a seating surface and a seat frame; a four-bar linkage folding system having four pivot point and four linkages including the support frame defining a first linkage, the upper extension of the rear leg defining a second hnkage, a linking member pivotaUy coupled to and between the upper extension and the seat defining a third linkage, and a side of the seat defining a fourth linkage; and at least one kick-out tab attached to the seat, the kick-out tab shaped and positioned such that the upper extension of the at least one rear leg contacts the at least one kick-out tab urging the seat in an outward direction.

55. A folding chair comprising: a support frame having a back support portion, front leg portions, and rear legs; a seat pivotaUy coupled to the support frame; a back support, coupled to the support frame, having a lumbar support member extending down from the back support to reach a lumbar region of a user's back.

56. The folding chair of claim 55, wherein the back support is flexible and displaces in response to the user's weight.

57. The folding chair of claim 55, wherein the flexible back support has a perimeter flange protruding from a front surface of the back support and extending across a front portion of the support frame, and wherein the perimeter flange displaces across the front portion of the support frame in proportion to a load apphed to the back support.

58. The folding chair of claim 57, wherein the perimeter flange extends across a gap created between the flexible back support and the support frame, such that when a load is apphed to the back support and the back support flexes, causing the gap to open, the perimeter flange conceals the gap as the flexible back support goes from a loaded position to an unloaded position, thereby preventing pinching of articles of clothing or skin of a user.

59. The folding chair of claim 55, wherein the lumbar support member has a horizontal concave curvature integraUy formed with a vertical convex curvature.

60. The folding chair of claim 55, further comprising: first and second folding systems for folding the folding chair from an opened unfolded position to a closed folded position.

61. The folding chair of claim 55, wherein the back support has a removed upper portion exposing a portion of the support frame to define a handle, such that the support frame may be grasped and used as a handle for lifting the folding chair.

62. The folding chair of claim 55, wherein the lumbar support member extends from the back support into a space between the back support and seat, and wherein the seat pivots in a downward direction away from the back support and lumbar support member, such that the seat folds without interfering with the lumbar support member.

63. The folding chair of claim 55, wherein the lower lumbar region of the back support is lateraUy unattached to the support frame, but integraUy connected to the back support.

64. The folding chair of claim 55, wherein the lumbar support member has a reduced cross-sectional area for greater flex.

65. A folding chair comprising: a support frame having a back support portion and first and second side supports extending to form front leg portions; a seat pivotaUy coupled to the support frame; rear legs pivotaUy coupled to the support frame; and a flexible back support, coupled between the first and second side supports and having a protrusion extending downwardly from the flexible back support and defining a lumbar support member, the lumbar support member being secured to the support frame through the flexible back support without directly attaching lateraUy to the support frame, the lumbar support member being integraUy formed with the flexible back support aUowing the lumbar support member to flex with respect to the flexible back support and move with respect to the support frame.

66. A folding chair comprising: a rigid support frame having a rigid back support perimeter and first and second side supports; a seat, pivotaUy coupled to the support frame; a flexible back support, coupled to the support frame, having a perimeter flange disposed across the rigid back support perimeter and free to move with respect to the rigid support frame in response to a load apphed to the flexible back support.

67. The folding chair of claim 66, wherein the perimeter flange extends across a gap created between the flexible back support and the support frame, such that when a load is apphed to the back support and the back support flexes, causing the gap to open, the perimeter flange conceals the gap as the flexible back support goes from a loaded position to an unloaded position, thereby preventing pinching of articles of clothing or skin of a user.

68. A folding chair comprising: a support structure having a back support portion and leg supports; and a stabilizing seat, pivotaUy coupled to the support structure, and having a seating surface and at least one upper projecting ahgnment member configured to substantiaUy engage a second chair to stabilize and prevent relative lateral movement between the two chairs when in a folded and stacked relationship.

69. The folding chair of claim 68, wherein the at least one upper projecting ahgnment member protrudes from a rear comer of the seat.

70. The folding chair of claim 68, wherein the stabilizing seat includes two upper projecting ahgnment members each protruding from a rear comer of the seat.

71. The folding chair of claim 68, wherein the at least one upper projecting ahgnment member is integraUy formed with the seating surface, and protrudes substantiaUy perpendicular to the seat surface, said ahgnment member including a seating curvature forming a continuous extension of the seating surface.

72. The folding chair of claim 68, wherein a majority of the stabilizing seat collapses into a volume defined by the support structure with the at least one upper projecting ahgnment member protruding therefrom.

73. The folding chair of claim 68, wherein the at least one upper projecting ahgnment member nests with a support structure of a second adjacent and stacked chair.

74. A folding, stabilizing seat comprising: a seating surface configured for pivotaUy coupling to a first folding chair; and at least one upper projecting ahgnment member integraUy formed with the seating surface, the at least one upper projecting ahgnment member configured to substantiaUy engage a second adjacent folded and stacked chair of common geometry to stabilize and prevent lateral movement between the first and second chairs.

75. A folding chair system comprising: a first folding chair having a support frame, a back support, and a stabilizing seat, the stabilizing seat having a seating surface and at least one upper projecting ahgnment member; and a second folding chair having a support frame, a back support, and a stabilizing seat such that the at least one upper projecting ahgnment member of the first folding chair substantiaUy engages the support frame of the second folding chair when the first and second folding chairs are folded and stacked to prevent lateral movement between the first and second folding chairs.

76. The folding chair system of claim 75, wherein the upper projecting ahgnment members protrude from rear comers of the seats.

77. The folding chair system of claim 75, wherein the stabilizing seats includes two upper projecting ahgnment members each protruding from rear comers of the seats.

78. The folding chair system of claim 75, wherein the upper projecting ahgnment members are integraUy formed with the seating surfaces, and protrude substantiaUy perpendicular to the seating surfaces, said ahgnment members including seating curvatures forming a continuous extension of the seating surfaces.

79. The folding chair system of claim 75, wherein a majority of the stabilizing seats coUapses into a volume defined by the respective support stmctures with the upper projecting ahgnment members protruding therefrom.

80. The folding chair system of claim 75, wherein the upper projecting ahgnment member of the first chair nests with the support stmcture of the second chair.

81. A folding chair comprising: a support structure having a back support portion and leg supports including front and rear legs; a seat, pivotaUy coupled to the support stmcture, and pivoting between an open unfolded position, and a closed folded position; and at least one indexing foot, coupled to at least one of the front or rear legs, shaped and positioned to engage at least one leg support of an adjacent folding chair to resist relative movement between the chairs when in a folded and stacked position.

82. The folding chair of claim 81, wherein the at least one indexing foot includes a protrusion extending from the foot and being sized and configured to engage a leg of an adjacent stacked chair to resist relative lateral movement.

83. The folding chair of claim 81 , wherein the at least one indexing foot includes a protmsion extending from the foot and being sized and configured to abut a foot of an adjacent stacked chair to resist relative longitudinal movement.

84. The folding chair of claim 81, wherein the at least one foot has opposite first and second protmsions, the first protmsion extending from the foot and being sized and configured to engage a leg of an adjacent stacked chair to resist relative lateral movement, the second protmsion extending from the foot and being sized and configured to abut a foot of an adjacent stacked chair to resist relative longitudinal movement.

85. The folding chair of claim 81, wherein the at least one indexing foot includes a recess being sized and configured to receive a leg of an adjacent stacked chair to resist relative lateral movement.

86. The folding chair of claim 81 , wherein the at least one foot has a recess and an opposite protmsion, the recess being sized and configured to receive a leg of an adjacent stacked chair to resist relative lateral movement, the protmsion extending from the foot and being sized and configured to abut a foot of an adjacent stacked chair to resist relative longitudinal movement.

87. The folding chair of claim 81, wherein the at least one foot has a toe and a heel.

88. The folding chair of claim 87, wherein the toe includes a protrusion extending therefrom being sized and configured to engage a leg of an adjacent stacked chair to resist relative lateral movement.

89. The folding chair of claim 87, wherein the heel includes a protrusion extending therefrom being sized and configured to abut a foot of an adjacent stacked chair to resist relative longitudinal movement.

90. The folding chair of claim 87, wherein the heel includes a recess being sized and configured to receive a leg of an adjacent stacked chair to resist relative lateral movement.

91. A folding chair comprising: a support stmcture having a back support portion and leg supports including front and rear legs; a seat, pivotaUy coupled to the support stmcture, and pivoting between an open unfolded position, and a closed folded position; and indexing feet coupled to the front and rear legs, the indexing feet each having a protmsion shaped and positioned to abut a leg or foot of another adjacent folding chair to resist relative movement between the chairs when in a folded and stacked relationship.

92. The folding chair of claim 91, wherein the indexing feet further comprise a receiving recess located opposite the protmsion, the receiving recess being shaped and positioned to receive the support stmcture of an adjacent chair to resist relative lateral movement between the chairs when in a folded and stacked relationship.

93. The folding chair of claim 91 , wherein the protrusion extending from the feet is sized and configured to abut the feet of an adjacent stacked chair to resist relative longitudinal movement.

94. The folding chair of claim 91 , wherein the protmsion is a first protrusion extending from the indexing feet and being sized and configured to engage a leg of an adjacent stacked chair to resist relative lateral movement; and further comprising a second opposite protmsion extending from the indexing feet and being sized and configured to abut the feet of an adjacent stacked chair to resist relative longitudinal movement.

95. A folding chair comprising: a support frame having a back support portion and first and second side supports extending to form first and second front legs; a seat pivotaUy coupled to the support frame; a back support attached to the support frame; first and second rear legs pivotaUy coupled to the support frame; and front and rear indexing feet coupled to the front and rear legs, respectively, the indexing feet each having a receiving recess shaped and positioned to respectively receive and index with legs of an adjacent folding chair and to resist relative lateral movement between the chairs when in a folded and indexed position, and further having an opposite protrusion shaped and positioned to respectively abut indexing feet of an adjacent folding chair to resist relative longitudinal movement between the chairs when in a folded and indexed position.