US 2871921 A
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Description (OCR text may contain errors)
Feb. 3, 1959 I ARNOLD v 7 2,871,921
COLLAPSIBLE FOLDING CHAIR Filed May 22, 1956 2 Sheet-Sheet 1 FREDRIC ARNOLD INVENTOR.
9 F. ARNOLD COLLAPSIBLE FOLDING CHAIR Filed May 22, 1956 2' Sheets-Sheet 2 FIG. 9.
FREDRIC ARNOLD INVENTOR.
United States Patent COLLAPSIBLE FOLDING CHAIR Fredric Arnold, Roslyn Heights, N. Y.
Application May 22, 1956, Serial No. 586,612
4 Claims. (Cl. 155-140) This invention relates to collapsible folding chairs and more particularly to chairs of this type which are formed in large degree of lightweight metal tubular elements and which when collapsed and folded occupy a minimum amount of space.
Lightweight folding chairs formed of tubular metal elements, such as aluminum, are currently being manufactured and marketed. Although such chairs have many desirable characteristics, considerable difficulty has been encountered in the design and manufacture of chairs of the folding type which when erected forms a stable and rigid body support. Furthermore, although the amount of space required in the packaging and shipment of such chairs is considerably reduced by reason of their folding characteristics, nevertheless the item still forms a relatively bulky package and occupies considerably more space than is desirable. The bulk presented by the chair even when in folded condition has added materially to the cost of shipment and creates storage problems for the chair when not in use.
It is therefore among the objects of this invention to provide. a chair which when erected forms a rigid and stable body support while maintaining desirable characteristics of seating comfort for the user.
Another object of this invention is to provide a chair which is capable of being both collapsed and folded so as to occupy a minimum amount of space in shipment and storage.
It is also an object of this invention toprovide a chair of the character indicated wherein the repeated collapse and erection of the chair, as Well as the constant folding and unfolding thereof, will not efiect the rigidity and stability of the chair as a body supporting device.
Another object of this invention is to provide a chair which is capable of being shipped in collapsed and folded condition and which may be readily assembled and unfolded without the use of any tools or extraneous fastening elements in a minimum amount of time and with a minimum amount of effort. 7 1
It is also an objectof this invention to provide a chair of the character indicated having flexible seat and back supporting members which are kept in taut and body supporting condition by means provided in the chair structure;
Another object of this invention is to provide a chair of the character indicated wherein seat and back supporting elements are formed of a flexible material and wherein means are provided for attaching said flexible material to the chair frame in an efficient and economical manner and to achieve an even distribution ofstrain along the attachment region.
Other and further objects, benefits and adavntages of this invention will become apparent from the description thereof contained in the annexed drawings, specification and claims or will otherwise become obvious. It will be understood that the invention herein disclosed may be employed for other purposes for which the parts, struc-' ture and arrangements are adapted.
2,871,921 Patented Feb. 3, 1959 ice In the accompanying drawings:
Figure 1 is a perspective view of a chair in accordance with the present invention;
Figure 2 is a side elevational view of said chair on a. reduced scale;
Figure 3 is a side elevational view of the chair as shown in Figure 2 wherein the chair is shown in partly folded condition; a
Figure 4 is a perspective view of said chair on a dilferent scale in partially collapsed condition;
Figure 5 is a perspective view of said chair in folded condition;
Figure 6 is a cross-section of Figure 5 taken along line 66 thereof showing the side brace link element arrangement on an enlarged scale;
Figure 7 is a fragmentary cross-section showing the telescopic action of the end of a chair leg with respect to a portion of its associated transverse brace;
Figures 8 and 9 are fragmentary cross-sections of the seat support bar illustrating the manner in which the end edges of the flexible seat material are secured in position; and
Figure 10 is a perspective view of a chair similar to Figure 1 in an exploded form illustrating the relative positions of the chair elements with respect to the side frames.
In its broad aspect the device comprising the present invention contemplates a chair structure wherein a pair of chair side frame assemblies are provided and interconnected by means of flexible seat and back supporting elements or bands. The side frames are arranged so as to be foldable to occupy aminimum'amount of space. Transverse brace means are provided for maintaining said side frames in parallel spaced relationship so that the seat and back bands are stretched therebetween and retained in taut condition, as for use. Said transverse bracing means are additionally disengageably connected with said side frame assemblies to thereby permit them to be detached from the side frames and to be thus collapsed and moved toward each other upon such removal of Said bracing elements to thereby further reduce the amount of space occupied by the chair elements when thus folded and collapsed.
The general construction of a chair in accordance with the instant invention is illustrated in Figures 1 and 10. As may be seen from said figures, the chair comprising 7 the instant invention includes a pair of side frame assemblies designated generally by the numerals20 and 21 which are permanently interconnected by means of a flexible fabric seat 22 and a similar fabric back rest 23. The chair structure is completed by a plurality of transverse brace members which maintain the chair in assembled form but are disengageably associated therewith. Thus,
as may be seen from the exploded view of Figure 10, the chair side frame assemblies aremaintain'ed in spaced apart relationship when the chair is assembled for use by means of front and rear transverse brace members 24 and 25 respectively which also act as base supports for the chair, a transverse back brace 26 and an intermediate transverse brace 27. The bracing members 24, 25, 26 and 27 act to maintain the side supports comprised of the side frame assemblies 20 and 21 in spaced apart relationship and to thereby stretch the seat and back rest of the chair therebetween and maintain it in taut condition to form a comfortable rigid and stable body supporting structure, as will more particularly be described hereafter.
As may be seen from Figures 1 and 10, as well as Figures 2 and 3, the side support frame assemblies 20 and 21 are similar for each side of the chair. Said support frames each include a front leg28 and rear leg 29. These legs are advantageously formed of a tubular material, such as aluminum tubing, to provide a structure of adequate rigidity and strength while maintaining the benefits of a lightweight structure. Each of the side frame assemblies is additionally provided with an arm rest 36 positioned along the upper ends of each set of front and rearlegs. Said arm rest 39 is advantageously formed of a right angled length of aluminum strip and extends, when the chair is assembled for use, parallel with the floor or ground support. The portion of said arm rest 30, which is thus disposed in a horizontal plane, provides a suitable arm rest for the person occupying the chair while the portion of the arm rest member disposed in a vertical plane permits the suitable pivotable connection of the other elements of the side assembly thereto. Each of the side frame assemblies is additionally provided with a substantially vertically disposed back rest supporting member 31 and a horizontal seat supporting bar 32. As may be more clearly seen from Figures 2 and 3, the upper extremities of the front and rear legs 28 and 29 are pivotally connected to the vertically disposed portion of arm rest 39, as shown at 33 and 34. An additional pivotal connection is provided between the rear extremity of the arm rest andthe back supporting member 31 inter mediate its ends as shown at 56. These pivotal connections may be accomplished by inserting rivets or bolts through registering perforations formed through the material of the arm, legs and back support. Each side frame assembly additionally includes a pivotal connection between an intermediate portion of front leg 28 and the horizontal seat supporting bar 32 as shown at 35.
A pivotal connection is provided between the lower extremity of back support member 31 and the rear extremity of seat supporting bar 32, as shown at 36 by means of a floating bracing link 37. Said bracing link 37 additionally provides a pivot point for rear leg 29 intermediate its ends as shown at 38. As may be more clearly seen from the foregoing figures and Figure 6, the bracing link 37 comprises a substantially L-shaped member formed with arms 41 and 42 respectively. Link 37 may be advantageously formed of a suitably bent metal rod or wire and is provided with terminal portions 39 and 40 extending at right angles with respect to the plane of said L-shaped portion. Terminal portion 39 of link 37 is passed through registering perforations formed in the lower extremity of back support member 31 and the rear extremity of seat supporting bar 32 and constitutes a common pivot pin therefor while terminal portion 40 of link 37 is passed through perforations formed in the walls of the tubular member comprising the rear leg 29 as shown at 38 and forms a pivot pin therefor. The end of terminal portion 39, which passes through the seat supporting bar 32, is provided with a threaded portion and locked in position by means of nut 43. The end of terminal portion 40 is similarly locked in position by means of a locking ring or washer 44.
It will be apparent from the foregoing that a parallel form of linkage is formed between the arm rest and seat supporting bar parallel therewith on the one hand and the back support member 31 and the front leg 28 on the other by reason of this pivotal interconnection. Rear leg 29 is pivotally connected at its upper extremity to the arm rest and is provided with a floating intermediate linkage to the chair back support 31 by means of the aforesaid link 37. As a result of this floating linkage between the rear leg and the remainder of the chair side support frame assembly, said side frame may be folded together in the manner illustrated in Figure 3. Said figure illustrates an intermediate stage in the process of folding the side frame assembly. For the purposes of clarity of illustration it will be understood however, that the side frame is capable of being and is actually further folded together to a position wherein all of the members comprising the side frame are substantially parallel and contiguous with each other and occupy a minimum amount of space. Thiscondition is apparent in Figurej wherein an assembled chair is shown in folded condition. The
4 folded condition of each of the side frames would of course be similar even with the transverse braces removed as when the chair is collapsed.
In addition to performing the function of providing a floating linkage between the lower and rear extremities of the back support member 31 and seat support bar 32 respectively, the link 37 also performs the function of acting as a brace for the chair when erected and in use. in this connection it should be noted that when the chair is erected for use, the L-shaped portion of the link bears against said leg and urges it toward the seat brace bar 32. Thus, the longer arm 41 of the side brace rests in parallel contact with a portion of rear leg 29 and serves as a brace therefor to materially reduce or completely prevent lateral sway in the chair when assembled for use. Additionally, the L-shaped portion of the link bearing against the leg body exerts sufiicient friction to act as a lock for the chair to prevent it from being accidentally folded and further acts as a lock to maintain the chair in folded condition as illustrated in Figure 5 so as to prevent it from being accidentally opened. The pressure exerted by the link provides a suificient frictional engagement between the parts to prevent this type of accidental movement while at the same time it does not act to increase the amount of effort required to open or fold the chair to an unreasonable extent.
The chair seat 2 2 and back rest 23 interconnect the side frame assemblies at their respective location. Said seat and back may be formed of any suitable flexible fabric or plastic material, as is well known in the art. It is common practice to employ a fabric woven of synthetic resin filaments. Heretofore considerable difficulty has been encountered in mounting such sheets of flexible material securely. It has been difiicult to achieve an even distribution of strain along the secured end edges of the fabric and as a result of this the fabric has often become torn or otherwise disengaged from its point of securement. In order to obviate this difficulty the instant chair employs a clamping bar arrangement for securing the end edges of the seat and back fabric or material to the seat supporting bar and back support respectively. Thus, as may be seen more particularly from Figures 8 and 9, theinstant invention employs a clamping bar 45 which is coextensive with the width of the fabric to be attached to the seat supporting bar. Clamping bar 45 is formed of a thin strip of metal from the body of which tongues 46 have been struck as by stamping. The seat supporting bar is provided with perforations therethrough at points in registration with the tongues 45 extending from said clamping bar 45. In order to secure the end edge of the fabric to the seat supporting bar, the end portion thereof is folded upon itself and around clamping bar 45 and the tongues 46 are forced through the material. The clamping bar is then brought into position against the seat supporting bar 32 and tongues 46 are passed through the perforations 47 formed in said seat supporting bar and the ends of said tongues are bent over to firmly secure said clamping bar to the seat supporting bar. By means of this arrangement the end edge of the fabric comprising the seat is anchored along its entire width and the stress to which the seat is subjected when in use is evenly distributed along the entire length of the seat supporting bar. In the same manner a clamping bar is employed in connection with each back support to firmly secure the flexible chair back material to said back supports 31. In this. case however, perforations are provided in the body of the wall of the tube in registration with the projecting tongues of the clamping bar and the backing material is again folded upon itself and around the clamping bar. The tongues of the clamping bar are then passed through the perforations in the tube wall. In order to bend the tongue ends over against the interior of the tube wall, it is merely necessary to force a cylindrical mandrel into the interior of the tube thereby automatically bending over the tongue ends against the interior wall of the tubing forming the back supports for the chair. In each case the clamping bar serves to anchor the end edge of the back rest material along the entire width thereof and serves to achieve an even distribution of stress therealong.
From the foregoing description it will be apparent that a structure is achieved at this point wherein two foldable side frame assemblies are interconnected by means of sheets of flexible fabric which comprise the seat and back rest for the chair respectively. Since there are no transverse rigid members interconnecting the side frames at this point, said side frames may be brought into close proximity as is illustrated in Figure 4. In fact they may be brought into actual contact with one another. It will be further apparent that when so brought into contact and folded as indicated in Figure 3, the side frames and seat occupy a very small volume of space.
The chair structure is completed by means of transverse front and rear base brace members 24 and 25. These base brace members are formed of tubing similar to that from which the chair legs are formed but are of a smaller diameter. Front and rear base brace members 24 and 25 respectively are of substantially U-shape and comprise horizontal base portions 49 from which there extend the vertically disposed arms 50. As heretofore indicated the base members 24 and 25 are formed of tubing which is of smaller diameter than the diameter of the tubing which comprises legs 28 and 29 of the chair so that the arms 50 are adapted to be telescopically received within the ends of said legs as may be seen more clearly in Figure 7. The tubing forming the legs and base members is so dimensioned as to permit the snug fit between these parts but nevertheless to permit the insertion and removal of the base members from the chair legs. In a similar manner a substantially U-shaped transverse back brace member 26 is provided for the back of the chair and is similarly U-shaped having a horizontal transverse portion 52 from which arms 53 depend. Said arms are adapted to be similarly telescopically received within the open ends of the tubular members comprising the back supports 31 for the chair. An intermediate transverse brace 27 is provided and comprises a tubular member having flattened ends 48 formed with substantially right angled bends which are adapted to be received in slots 51 formed in the wall of the tubing comprising the front legs 28.
The manner of assembling the chair may be more clearly seen in Figures 4 and 10. As may be seen from said figures, in the first step of assembling or erecting the chair the side frame assemblies are unfolded to assume the position indicated in Figure 4. The side frames are then moved to the spaced apart parallel relationship indicated in Figure 10, in which position the transverse back a brace member 26 isplaced into position by inserting the dependent arms 43 thereof into the upper extremities of the back rest supporting members 31. The flattened and bent ends 48 of intermediate transverse brace 27 are then inserted into slots 51 formed in the wall of the tubing comprising the front legs 28. Thereupon the upwardly extending arms 50 of the transverse base brace members 24 and 25 are telescopically inserted into the lower extremities of the front and rear legs 28 and 29 respectively. in this connection it should be noted that the fabric forming the seat and back rest is advantageously somewhat shorter than the distance between the arms of the brace members so that in inserting the brace members into position the fabric of the seat and back rest is made taut and is slightly stretched so that the tension of the seat and back rest'fabric serves to increase the friction between the ends of the brace members and the walls of the leg and back rest supporting members thereby assuring that these members will be maintained firmly in relative position and that the entire chair structure is rigid. In this connection it should also be noted that when a person is seated in a chair the additional tension applied to the seat and back rest is communicated to the legs and v fabric parallel with the warp threads.
back rest supporting members so that additional pressure is applied against the ends of the various transverse braces, thus additionally assuring rigidity for the chair structure. The dis-assembly of the chair is readily ac complished by reversing the process and withdrawing the ends of the brace members from their position in the leg and back rest supporting members. The side supporting frames may then be readily folded and brought into contact with each other in order to completely collapse the chair. A convenient form of accomplishing this is to wind the fabric of the seat and back rest around one of the folded side frames thereby forminga neat and compact bundle which occupies a minimum amount of space since the legs, back rest supports, the arm rests and the seat supporting bars are in substantial parallelism and contact with each other. The tranverse braces may then be positioned so that their base portions are parallel with the members of the folded side frames, as is the horizontal transverse portion of the transverse back brace. The intermediate brace is, of course, similarly positioned. The entire bundle thus comprises a group of longitudinally extending elements in close proximity with each other and occupies a volume determined largely by the combined area of their cross-sections and length. Thus, a chair of this type and of a size adapted to be occupied by an average adult person may be conveniently packed into a rectangular container 5 /2 x 5 /2 X 28". The compact manner in which the instant chair may be folded and collapsed to occupy a small volume of space, as indicated, results in a very substantial savings in storage space and shipping cost.
.The chair structure itself is. considerably improved by the employment of the brace arrangement hereto:
fore disclosed. The intermediate brace 27 contributes appreciably to the rigidity of the chair structure and resists twisting forces to. which the interconnected side frames are subjected during use. In this connection it should be noted that the ends of said braces are flattened so as to provide a considerable transverse bearing surface formed by the parallel walls of the flat tube ends. The flat ends 48 fit snugly into the elongated slots .51 which have complementary parallel disposed spaced side walls thereby causing said ends to bear against the walls of the slot and to resist the torque or twisting action to which the interconnected side frames are subjected.
The method of connecting the fabric seat 22 and the back rest 23 is additionally significant in that the need for sewing along the marginal edges of these elements is entirely eliminated. In this connection it should be noted that where, as heretofore, sewing has been employed to secure the end edges of the fabric, the sewing thread forms one of the weakest links in the connection.
This results from the fact that the entire seat or back rest assembly is held 'by the sewing thread. There are limitations in the employment of heavy gauge threads and even these have not proven to be satisfactory since they tend to break under the constant abrasive action against the threads of the fabric to which they are subjected in use, particularly as the weight of the user is shifted. The sewing threads therefore constitute one of the first points at which the fabric breaks loose. The instant construction permits the entire elimination of this weak point of connection and additionally results in substantial economies in manufacture. It should additionally be noted that the tongues 46 of the clamping bars 45 are disposed so that their faces extend trans versely across the clamping bar and they thus enter the These are the threads which extend between and interconnect the side frames, extending transversely across the chair. By disposing the tongues parallel with these warp threads, they are not injured or broken as the tongues penetrate the fabric since the tongues pass therebetween. Although some of the woof threads extending parallel with the clamping bar and fabric supporting elements may be im 7 jured, this does not materially reduce the strength of the fabric. It is the warp threads which are subjected to the considerable tension and abrasion in use and consequently the breakage of even one or a small number of these threads would form an initial point of weakness at which a tear could begin. By disposing the tongues in the manner indicated, these threads are in no-wise injured during the attachment process or by the attachment means.
I have here shown and described a preferred embodiment of my invention. It will be apparent, however, that this invention is not limited to this embodiment and that many changes, additions and modifications can be made in connection therewith without departing from the spirit and scope of the invention as herein disclosed and hereinafter claimed.
1. A chair comprising a pair of side frames, each of said side frames including a front and rear leg member, arm rest and back support members and a seat supporting bar, said members and bar comprising each frame being pivotally interconnected for folding movement, a detachable transverse brace member interconnecting the front leg members of said frames and a detachable transverse brace member interconnecting the rear legs of said frames, said brace members each including a horizontal portion and being detachably interconnected with the terminal portions of said leg members, a transverse back brace provided with a horizontal transverse portion detachably interconnected with said back support, a transverse brace interconnecting the intermediate portions of said front legs, a flexible seat and a flexible back rest secured to said seat supporting bars and extending between said seat supporting members and said back supports.
2. A chair comprising a pair of side frames, each of said side frames including a front and rear leg member, arm rest and back support members and a seat supporting bar, said members and bar of each frame being pivotally interconnected for folding movement, a pair of U-shaped transverse base brace members interconnecting the front and rear legs of said frames respectively, said base members including horizontal ground engaging portions and being provided with arms extending therefrom detachably interconnected with the terminal portions of said leg members, a transverse U-shaped back brace provided with a horizontal transverse portion and arms depending therefrom detachably interconnected with the back supports of said frames, a transverse brace interconnecting the intermediate portions of said front legs, a flexible seat and a flexible back rest secured to the seat supporting members and said back supporting members of said frames respectively and extending therebetween.
3. A chair comprising a pair of side frames, each of said side frames including a front and rear leg member, an arm rest and a seat supporting bar and a back support member, said arm rest and back support being disposed in horizontal spaced apart relationship when said chair is erected for use, said front and rear leg members and said back support being substantially vertically disposed, a pivotal connection between the upper extremity of said front leg member and the forward end of said arm rest and a pivotal connection between the forward extremity of said seat supporting bar and at an intermediate portion of said front leg, a pivotal connection between the upper extremity of said rear leg and said arm rest at an intermediate portion of said arm rest, an additional pivotal connection between said back rest supporting member at an intermediate portion thereof with the rearward extremity of said arm rest and a common pivotal connection between the lower extremity of said back rest supporting member, the rearward extremity of said seat supporting bar and an intermediate portion of said rear leg member, said common pivotal connection being comprised of a substantially L-shaped link, said link being provided with terminal portions at the extremities thereof extending normally with respect to the plane thereof, one of said terminal portions forming a pivot pin for the lower extremity of said back rest support and said seat supporting bar, the other of said terminal portions comprising a pivot pin for the intermediate portion of said rear leg member.
4. The device according to claim 3 wherein one of the arms of said L-shaped linking member is disposed parallel with and bears against the intermediate portion of said rear leg to form a brace therefor.
References 'Cited in the file of this patent UNITED STATES PATENTS 589,947 Jensen Sept. 14, 1897 1,691,604 Harman Nov. 13, 1928 1,813,030 Brown July 7, 1931 1,856,759 Grondin May 3, 1932 1,905,830 Ericson Apr. 25, 1933 1,942,112 McQuilkin Jan. 2, 1934 2,608,240 Booth Aug. 26, 1952 2,629,432 Hanslick Feb. 24, 1953 2,649,894 Simmons Aug. 25, 1953 2,695,654 Boyd Nov. 30, 1954 2,709,481 Budai May 31, 1955