Folding Furniture Construction

Abstract

An all metal folding furniture construction having front and rear sets of pivotally connected cross legs including a jointed locking bracket connecting the cross members extending between each pair of aligned front and rear legs. The jointed bracket includes a pair of U-shaped links pivoted to each other at one end and to the cross members at their other ends. Abutment surfaces are provided to lock the rotational position of the bracket when the joined ends of the links pass below the line joining the pivots at the cross members. The chair includes a side rail and an overlying runner pivoted thereto between which the fabric seat passes. The hinges connecting the rails and runners are spaced further apart than the depth of the seat and a pair of co-operating retaining flanges hold the welt and core of the seat in place regardless of the pivotal position of the side rail and runner. The side rail also defines an anvil spaced inwardly from the retaining flange to support the seat and in co-operation with the clamping flange on the runner, serves to selectively clamp the seat in position. The stool includes a side rail having a curved support surface to support the seat adjacent the welt and core and a key hole slot which passes along the length thereof to selectively retain the welt and core of the seat therein.

Description

BACKGROUND OF THE INVENTION

Heretofore, folding furniture such as chairs and stools have used a jointed bracket connected to the front set of cross legs to hold the legs in an expanded operative position. Because these jointed brackets have had little lateral strength, they have frequently collapsed causing the furniture to be rendered useless. Moreover, since the bracket was located nearer the pivot point of the cross legs than the forces exerted on the legs when in use, the brackets were subjected to high stress levels causing a high wear rate and a low useful life. The fact that the bracket was located on only the front set of legs caused the stability of the furniture to be affected.

Also, most prior art furniture either had the fabric seat permanently attached to the frame structure or the frame structure had to be partly disassembled in order to remove the seat. In both instances, the replacement of the fabric seat was both tedious and time consuming. This furniture generally had the fabric seat connected to the frame structure through a relative narrow area in the vicinity of the welts at opposite sides thereof. Such a connection caused localized high stress levels which resulted in early fabric failure.

SUMMARY OF THE INVENTION

These and other problems and disadvantages associated with the prior art are overcome by the invention disclosed herein by providing a jointed locking bracket for maintaining the furniture in a set up operative condition which has sufficient lateral strength to prevent collapse during use and which is located to produce a stable structure. Moreover, the fabric seat can be removed easily without partly disassembling the furniture and the seat is supported along an area spaced from the welts therein to increase the seat life. The furniture frames are of an all metal construction to further provide a more stable structure.

The construction described herein is shown in two embodiments, a chair and a stool. Both embodiments have front and rear sets of pivotally connected cross legs with cross members extending between each pair of aligned front and rear legs, the cross members being connected by a jointed locking bracket to hold the frame in an operative set-up position. The bracket includes a first U-shaped link and a second U-shaped link which have a common center pivot with the other ends of the links pivoted on the cross members. The links have abutment surfaces which engage each other when the axis of the common central pivot passes below a line joining the pivots between the links and the cross members to hold the frame in an operative set-up position.

Each pair of aligned front and rear legs of the chair are connected by a side rail at their upper ends which includes a clamping and support anvil along its inside edge, an upstanding retaining flange along its outside edge and an upturned hinge ear at each end thereof adjacent the retaining flange on the outside thereof. An arm rest assembly is pivotally connected to each side rail which includes a runner. The runner overlies the side rail in its operative position and includes a depending clamping flange which overlies and clamps the fabric seat between it and the anvil, a retaining flange along the outside thereof which overlies the retaining flange of the side rail, and a depending hinge ear at each end thereof adjacent the retaining flange on the outside thereof. The juxtaposed hinge ears are pivoted in such a way that the retaining flanges are never spread as far apart as the diameter of the cores in the end welts of the fabric seat but the fabric seat will be supported and clamped between the anvil and clamping flange.

Each pair of aligned front and rear legs of the stool are also connected by a side rail at the upper ends thereof. The side rails define an upper curved support surface and are recessed along their outer edges with a keyhole slot to retain the cored welt of the fabric seat therein. Thus, the seat can be easily removed and is supported over a wide area to reduce the stress in the seat.

These and other features and advantages of the invention disclosed herein will be more fully understood upon consideration of the following specification and accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views and wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the invention embodied in a chair;

FIG. 2 is a perspective view of a second embodiment of the invention embodied in a stool;

FIG. 3 is a cross-sectional view taken along line 3--3 in FIG. 1 showing the jointed locking bracket;

FIG. 4 is an enlarged partial longitudinal cross-sectional view of the locking bracket;

FIG. 5 is a partial cross-sectional view taken along line 5--5 in FIG. 1;

FIG. 6 is a cross-sectional view similar to FIG. 5 showing the arm rest assembly being folded;

FIG. 7 is a partial side elevational view showing the hinge connection of the chair of FIG. 1;

FIG. 8 is a partial elevational view of the chair of FIG. 1 showing the back post with the fabric back removed;

FIG. 9 is a cross-sectional view taken along line 9--9 in FIG. 8;

FIG. 10 is a cross-sectional view taken along line 10--10 in FIG. 2;

FIG. 11 is a partial elevational view of the stool side rail showing the fabric seat removed and,

FIG. 12 is a cross-sectional view similar to FIG. 6 showing the arm rest assembly in an open condition.

These figures and the following detailed description disclose specific embodiments of the invention, however, it is to be understood the the inventive concept is not limited thereto since it may be embodied in other forms.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Referring to the figures, it will be seen that the invention is embodied in a chair 10 and a stool 11. Both the chair 10 and stool 11 include a frame F with a front set of pivotally connected cross legs 12 and a rear set of connected cross legs 14. The legs 12 and 14 are pivoted along a common axis A as seen in FIGS. 1 and 2. A cross member 15 connects each aligned pair of front and rear legs adjacent the lower ends thereof. The cross members 15 are connected through a jointed locking bracket 16 as best seen in FIGS. 3 and 4.

The jointed locking bracket 16 includes a first U-shaped link 18 including a central web portion 19 and a pair of flanges 20 along the sides of web portion 19, and a second U-shaped link 21 including a central web portion 22 and a pair of flanges 24 along the sides of web portion 22. The width of the second link 21 is such that it will just fit between the flanges 20 of link 18. The flanges 20 and 24 define aligned apertures 25 through one of their ends through which a pivot pin 26 is received. The web portions 19 and 22 are recessed at the juxtaposed ends of the links 18 and 21 along with those portions of the flanges 20 and 24 adjacent the web portions so that the web portions 19 and 22 can be aligned. The recessed ends of webs 19 and 22 provide abutment surfaces 28 which engage each other to lock the bracket 16 as will be explained below.

The opposite ends of flanges 20 and 24 are apertured at 29 which are aligned with like apertures 29 in pivot brackets 30 attached to the center of the cross members 15. An anchor pin 31 is received through each pivot bracket 30 and that end of the link 18 or 21 positioned therein to pivotally connect the bracket 16 between cross members 15. Thus, links 18 and 21 are pivoted to each other along a first axis B and to its corresponding cross member 15 through axis C or axis D. The abutment surfaces 28 are arranged so that they engage each other when the axis B moves a prescribed distance d below an imaginary line L passing through axes C and D as seen in FIG. 3 to prevent further downward pivotal movement of bracket 16 to lock the chair or stool in an operative set-up position. When the joined ends of links 18 and 21 are forced upwardly to move axis B above line L, the surfaces 28 will be pivoting away from each other to allow the chair or stool to be folded. In order for this arrangement to operate, axes B, C and D must be parallel to each other and to the common axis A.

Referring specifically to FIGS. 1 and 5-7, it will be seen that a side rail 31 connects the upper ends of each pair of aligned front and rear legs 12 and 14. Side rail 31 is a plate having a pair of reinforcing ribs 32 formed therein along the length thereof to incorporate sufficient strength in the rail 31 to support fabric seat 33 without collapsing. An anvil 34 is provided along the inside edge of each side rail 31 and an upstanding retaining flange 35 is provided along the outside edge of rail 31 to retain 31 to retain seat 33 as will be explained. An upstanding hinge ear 36 is provided at the forward and rear ends of the side rail 31 to pivotally connect the arm assembly 40 to side rail 31. Since the length of side rail 31 is greater than the depth of seat 33, the seat will pass between the front and rear ears 36.

An arm assembly 40 is pivotally connected to each side rail 31 and includes a runner 41 which overlies the side rail 31. Each runner 41 is a plate having reinforcing ribs 42 along the length thereof similarly to the rail 31 with depending hinge ears 44 at each end thereof which lie in juxtaposition with the hinge ears 36 of rail 31. Aligned apertures 45 are defined by ears 36 and 44 arranged along a common axis E and a pivot pin 46 is received through the apertures 45 in the front ears 36 and 44 with a like pivot pin 48' received through the apertures 45 at the rear ears 36 and 44.

The runner 41 includes a retaining flange 48 which overlies the retaining flange 35 when the runner 41 is in its operative set up position as seen in FIG. 5. A clamping flange 49 is provided along the inside edge of the runner 41 and overlies the anvil 34 to selectively clamp the seat 33 between the flange 49 and anvil 34 as will be explained.

The fabric seat 33 is generally conventional in construction with a hem 38 along the front and back edges with a looped welt 37 on opposite ends thereof. A core 39 is carried in each welt as best seen in FIG. 7 and has a reduced diameter portion at each end thereof that fits within the hem 38 at the welt 37 to support the welt 37 at a constant diameter along its length and retain core 39 in the welt.

The spacing between the common axis E and the flanges 35 and 48 is such that welt 37 with core 39 therein will not pass between the flanges regardless of the relative pivotal position of the side rail 31 and runner 41 as best seen in FIG. 12. Thus, the seat 33 is installed by removing the cores 38, inserting the welts between the flanges 35 and 48 so that the welts 37 lie outside of the flanges and re-inserting the cores in the welts. When the bracket 16 is locked, then the seat 33 will extend between the side rails 31 and the cored welts 37 will be retained by flanges 35 and 48. The seat rests on and is supported by the anvils 34 spaced inwardly of the welts 37 and flanges 49 of runners 41 may be used to clamp the seat 33 to further reduce the stresses at the welt as will be explained. The flanges 35 and 48 are appropriately recessed at each end thereof as indicated at R to permit the passage of the hems 38 therebetween as seen in FIG. 7.

Each arm assembly 40 further includes a front upstanding post 50 attached to and extending upwardly from runner 41 and a rear post 51 also attached to the runner 41. An arm rest 52 extends between posts 50 and 51 with post 51 extending above the arm rest 52 to mount the fabric back rest 54 thereon as best seen in FIGS. 1, 8 and 9.

Referring specifically to FIGS. 8 and 9, the post 51 is provided with a plastic positioning member 55 which mounts the back rest 54. The member 55 is slidably received over the upper end of post 51 and has an upper retaining ridge 56 around its upper end with a lower retaining ridge 58 around its lower end.

The fabric back rest 54 is constructed similarly to the seat 33 with looped welts 59 at its opposite ends receivable over the members 55. The height of the back rest 54 is such that it will just fit between the retaining ridges 56 and 58 and the dimensions of the frame F are such that when the arm assemblies 40 are in their operative positions and the back rest 54 has been positioned over members 55, the back rest 54 will be taut when the locking bracket 16 is locked to hold the chair in its set up operative position.

The movement of the arm assemblies 40 toward each other is prevented by the flanges 49 of runner 41 engaging the anvils 34 of side rails 31. This also causes the hems 38 of seat 33 to be clamped by the flanges 49 and anvils 34. When a person leans back against the back rest 54, this serves to tighten the clamping action of the flanges 49 and anvils 34.

Referring now to FIGS. 2, 10 and 11, it will be seen that the stool 11 includes a pair of side rails 100, one of which connects the upper ends of each pair of aligned front and rear legs 12 and 14. Each side rail 100 defines a support surface 101 along the top thereof which extends to a key-hole slot 102 that extends along the length of rail 100.

The seat 33 is also used for the stool 11 but has a smaller size core 39' received therein which extends between the hems 38 so as to be received in the key-hole slot 102. The slot 102 has an enlarged circular portion 104 within which the cored welt is received and is connected to support surface 100 through a narrow opening 105 so that a lip 106 is formed on each side of the opening to retain the cored welt while the seat proper passes through the opening 105 which faces the outside edge of the rail 100. The surface 100 has a transitional primary support portion 108 adjacent the lip 106 which supports the seat 33 in its unloaded condition. The surface 100 also has a secondary support portion 109 adjacent the inside edge of the portion 108 which additionally supports the seat in its loaded condition. Portion 109 conforms to the catenary curve assumed by the seat when normally loaded so as to prevent high stress areas within the seat fabric.

Since the seat 33 can be easily slipped out of the slots 102 once the locking bracket 16 is released, the seat can be easily replaced. Moreover, the seat life is increased because the stress level within the fabric of seat 33 is kept to a minimum.

While specific embodiments of the invention have been disclosed herein, it is to be understood that full use may be made of modifications, substitutions and equivalents without departing from the scope of the inventive concept.

Claims

I claim:

1. A folding chair construction including two pairs of pivotally connected legs, a side rail connecting the upper ends of each pair of said legs, an arm assembly for each side rail including a runner and a rear post, a back rest detachably connecting said rear posts to maintain said chair in a set up condition, each of said side rails including an upstanding first retaining flange along the outboard edge thereof and an upstanding first hinge ear at the forward and rear ends thereof, each of said runners including a depending second retaining flange along the outboard edge thereof and a depending second hinge ear at the forward and rear ends thereof, said first and second hinge ears defining aligned apertures therethrough, a pivot pin received through each set of said aligned apertures in said hinge ears pivotally connecting said side rails to said runners, a flexible seat slidably received between said first and second retaining flanges and including a looped welt at opposite ends thereof, and a core member slidably received in each of said welts, said welts with said core member therein having a total diameter greater than the maximum opening defined between said first and second retaining flanges to prevent passage of said welts with said core members therein between said first and second retaining flanges regardless of the relative pivotal position of said flanges.

2. The folding chair construction of claim 1 wherein said first and second hinge ears are located forwardly and rearwardly of said first and second retaining flanges and define an opening therebetween greater than the length of said core members for said core member and said seat to pass therebetween to be retained by said first and second retaining flanges.

3. The folding chair construction of claim 2 wherein said side rails each further includes an upstanding anvil along the inboard edge thereof and wherein said runners each further include a depending clamping flange along the inboard edge thereof adapted to overlie said anvil when said side rail and said runner are pivoted toward each other to clamp said seat therebetween.

4. A folding chair construction including two pairs of pivotally connected legs, a side rail connecting the upper ends of each pair of said legs, an arm assembly for each side rail including a runner and a rear post, holding means connecting said rear posts to maintain said chair in a set up condition, each of said side rails including an upstanding first retaining flange along the outboard edge thereof and an upstanding first hinge ear at the forward and rear ends thereof, each of said runners including a depending second retaining flange along the outboard edge thereof and a depending second hinge ear at the forward and rear ends thereof, said first and second hinge ears defining aligned apertures in said hinge ears pivotally connecting said side rails to said runners, a flexible seat slidably received between said first and second retaining flanges and including a looped welt at opposite ends thereof, and a core member slidably received in each of said welts, said welts with said core member therein having a total diameter greater than the maximum opening defined between said first and second retaining flanges to prevent passage of said welts with said core members therein between said first and second retaining flanges regardless of the relative pivotal position of said flanges.

5. The folding chair construction of claim 4 wherein said first and second hinge ears are located forwardly and rearwardly of said first and second retaining flanges and define an opening therebetween greater than the length of said core members for said core member and said seat to pass therebetween to be retained by said first and second retaining flanges.

6. The folding chair construction of claim 5 wherein said side rails each further includes an upstanding anvil along the inboard edge thereof and wherein said runners each further include a depending clamping flange along the inboard edge thereof adapted to overlie said anvil when said side rail and said runner are pivoted toward each other to clamp said seat therebetween.