Patent Publication Number: US-6669280-B1

Title: Folding chair

Description:
REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of application, Ser. No. 09/625,704 filed on Jul. 25, 2000, now U.S. Pat. No. 6,394,541 which is a continuation of application, Ser. No. 09/236,945 filed on Jan. 25, 1999, now U.S. Pat. No. 6,106,056. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates the field of furniture, and more particularly to folding and portable chairs and the like. 
     BACKGROUND OF THE INVENTION 
     Chairs constructed of hinged or similar construction enabling them to be folded and easily carried from one place to another, and enabling them to be conveniently stored, have long been known. Examples of portable and/or folding chairs are shown in the following U.S. Patents: 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 U.S. Pat. No. 
                 Inventor 
               
               
                   
                   
               
             
            
               
                   
                 4,836,601 
                 Richard E. Cone 
               
               
                   
                 4,824,167 
                 King 
               
               
                   
                 4,671,566 
                 Knapp et al. 
               
               
                   
                 4,595,232 
                 Glenn et al. 
               
               
                   
                 4,533,174 
                 Fleishman 
               
               
                   
                 4,390,204 
                 Fleishman 
               
               
                   
                 3,453,022 
                 Lecuyer 
               
               
                   
                 2,074,998 
                 Kaufman 
               
               
                   
                 2,052,955 
                 Vanderminden 
               
               
                   
                 1,969,313 
                 Meeker 
               
               
                   
                 1,949,282 
                 Murray 
               
               
                   
                 1,443,734 
                 Craig 
               
               
                   
                   780,009 
                 Mettler 
               
               
                   
                   780,007 
                 Mettler 
               
               
                   
                   780,006 
                 Mettler 
               
               
                   
                   487,553 
                 Cole 
               
               
                   
                   233,732 
                 Cotton 
               
               
                   
                   220,949 
                 Wakefield 
               
               
                   
                   173,054 
                 Philips 
               
               
                   
                   
               
            
           
         
       
     
     However, each of the chairs of the prior art suffers from one or more inherent disadvantage. For example, one of the most common portable, folding chairs is the type made of aluminum tubing sections that are pivotally interconnected to define a sturdy seat, back and arm/armrest combination that is easily foldable from a substantially flat storage condition to an erected sitting condition. The arm rests of such chairs are typically a structural necessity and are desired by most people for comfort. However, some find the arm rest structures constraining. For example, persons of large girth may find it particularly difficult or uncomfortable to sit in, and to get in and out of, such chairs where the chair arms define a relatively narrow passage. The chair arms of such portable, folding chairs may also present an undesirable obstruction for persons engaged in a particular activity while sitting, such as guitar playing, fishing, etc. 
     Such chairs also typically comprise a frame with a textile or synthetic material that, once torn or damaged, cannot easily be replaced or, if it were replaced, would not be cost effective to do so. 
     What is needed is an improved folding, portable and lightweight chair that permits unrestricted use by large and small persons alike and which offers as little obstruction as possible from activity while seated in the chair. 
     SUMMARY OF THE INVENTION 
     Generally speaking there is provided a portable chair that may be folded between a substantially flat storage and transport condition and an unfolded, erected condition which includes a seat and a back, but which does not include arms. The chair could be constructed to form a seat to accommodate one normal sized adult or could be constructed to form a bench to accommodate two or more normal sized adults. 
     In one embodiment, a chair includes a first leg frame having first side rails with upper ends and a front cross rail connected to the upper ends; a second leg frame having second side rails; a back frame having a plurality of back side rails with upper ends and mutually parallel axes, and a top cross rail connected to the upper ends of the back side rails; a frame link assembly having a plurality of frame link members with mutually parallel axes; a flexible support member extending between the top cross rail and the front cross rail; and, a central back link. One of the second side rails is pivotally connected along a first axis to one of the back side rails and is pivotally connected along a second axis to one of the first side rails, and one of the frame link members is pivotally connected along a third pivot axis to one of the back side rails and is pivotally connected along a fourth pivot axis to one of the first side rails, and said central back link is pivotally connected along the first pivot axis to one of the second side rails and is pivotally connected along the third pivot axis to one of the frame link members. 
     It is an object of the present invention to provide an improved folding, portable chair. 
     It is another object of the present invention to provide an improved folding, portable chair that has no arm members that maintains a high degree of strength and stability. 
     Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiment. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the folding chair  10  in accordance with one embodiment of the present invention, and shown in the erected, rest position. 
     FIG. 2 is a side cross sectional view of the folding chair  10  of FIG. 1, taken along the lines  2 — 2  and viewed in the direction of the arrows. 
     FIG. 3 is a side cross sectional view of a portion of the folding chair  10  of FIG. 1, taken along the lines  3 — 3  and viewed in the direction of the arrows. 
     FIG. 4 is a perspective view of the folding chair  10  of FIG.  1  and shown in the mid-fold condition. 
     FIG. 5 is a side cross sectional view of the chair  10  of FIG. 2 shown stressed to the erected, stressed condition as a result of a person sitting therein. 
     FIG. 6 is a side elevational view of the folding chair  10  of FIG.  1  and shown in the collapsed condition. 
     FIG. 7 is a side elevational view of an alternative embodiment of the present invention. 
     FIG. 8 is a side elevational view of an alternative embodiment of the present invention. 
     FIG. 9 is a side elevational view of an alternative embodiment of the present invention. 
     FIG. 10 is a side elevational view of an alternative embodiment of the present invention. 
     FIG. 11 is a perspective view of a folding chair  110  in accordance with another embodiment of the present invention, and shown in the erected, rest position. 
     FIG. 12 is a side elevational view of an alternative embodiment of the present invention and shown in the erected, rest position. 
     FIG. 13 is a side elevational view of the chair of FIG.  12  and shown in the collapsed condition. 
     FIG. 14 is a perspective view of a folding chair  182  in accordance with an alternative embodiment of the present invention, and shown in the erected, rest position. 
     FIG. 15 is a perspective view of a folding chair  185  in accordance with an alternative embodiment of the present invention, and shown in the erected, rest position. 
     FIG. 16 is a side elevational view of the folding chair  185  of FIG.  15  and shown partially folded from the erected, rest condition of FIG.  15 . 
     FIG. 17 is a side elevational view of the folding chair of FIG. 16, and shown folded further from the erected, rest condition toward the collapsed condition than from the chair of FIG.  16 . 
     FIG. 18 is a side elevational view of the folding chair of FIG. 17 shown folded to the collapsed condition. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the purposes of promoting an understanding of the principles of 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, and any alterations or modifications in the illustrated device, and any further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention relates. 
     Referring now to FIGS. 1-3, there is shown a folding chair  10  in accordance with one embodiment of the present invention. Chair  10  generally includes back frame  12 , first leg frame  13 , second leg frame  14 , left frame link  15 , right frame link  16 , and flexible support  17 . Frames  12 ,  13 , and  14  and links  15  and  16  are each made of a material which provides an optimal balance among strength, weight, and cost. It is believed that aluminum tubing achieves this optimal balance, but other materials and shapes are also contemplated. 
     Back frame  12  has a generally U-shaped configuration consisting of left and right hollow tubing side rails  20  and  21 , respectively, and a top cross rail  22 . In one embodiment top cross rail  22  is solid, has a round cross section, and defines a pair of recesses  25  at each end (one shown in FIG. 3) that are shaped and sized to receive the complimentary-shaped upper rail portions  26  of the corresponding side rails  20  and  21 . A screw  24  extends through aligned holes in top cross rail  22  and the corresponding side rails  20  and  21  to firmly lock cross rail  22  to each side rail  20  and  21 . In the alternative, cross rail  22  may be of hollow tubing or may be of other suitable shape and size as is well known in the art. Cross rail  22  may also be secured to the front or back sides of side rails  20  and  21  by appropriate fasteners. Alternatively, side rails  20  and  21  may be of a particular shape to receive and be secured to a complementary-shaped cross rail  22 . 
     A cross bar  28  spans left and right side rails  20  and  21  and is fastened to the back side of and slightly more than half way down along rails  20  and  21  and is secured thereto by appropriate fasteners such as a bolt, lockwasher, and nut combination  29 . Protective end caps  27  are provided at the opposing outer ends of cross bar  28 . End caps  30  and  31  are provided at the ends of lower rail portions  32  and  33  of side rails  20  and  21 , respectively. End caps  30  and  31  are made of any appropriate material which provides some cushioning to the contact between rails  20  and  21  and first leg frame  13 . It is preferred that end caps  30  and  31  be comprised of an appropriate rubber or plastic. 
     Second leg frame  14  is tubular with a U-shaped configuration having left and right side rails  36  and  37 , respectively, and bottom cross rail  38  extending therebetween. Protective end caps are provided at the ends of upper portions  40  and  41  of side rails  36  and  37 . 
     First leg frame  13  has a generally rectangular box-shaped configuration and comprises a U-shaped tubular frame  44  and a front cross rail  45 . U-shaped tubular frame  44  is similar to second leg frame  14  and has left and right side rails  46  and  47 , respectively, and bottom cross rail  48  extending therebetween. Front cross rail  45  is substantially identical to top cross rail  22  and is rigidly connected to the upper ends of side rails  46  and  47  by screws  49  in a manner that is substantially identical to the way top cross rail  22  is secured to left and right side rails  20  and  21 . As with top cross rail  22 , front cross rail  45  may be of alternative shape and configuration so long as it creates, along with left and right side rails  46  and  47 , a strong and stable frame for tautly supporting flexible support  17 . 
     Left and right frame links  15  and  16  are also tubular and are provided with lower protective end caps  52  and  53  and upper end caps  54  and  55 , respectively. Upper end caps  54  and  55  are like end caps  30  and  32 , preferably made of an appropriate rubber or plastic to provide some cushioning to the contact between frame links  15  and  16  and second leg frame  14 . 
     As shown in FIGS. 1 and 2, side rails  36  and  37  of second leg frame  14  are coaxially rotatably connected at their approximate mid points by pivot pins  57  to the inside of and at the approximate mid points of side rails  46  and  47  of first leg frame  13 . Left and right side rails  36  and  37  are further pivotally connected by coaxial pivot pins  58  at their upper rail portions  40  and  41  to the inside of and a short distance above the lower ends of left and right side rails  20  and  21  of back frame  12 . 
     Further, as shown in FIGS. 1 and 2, left frame link  15  is pivotally connected at its lower end by pivot pin  61  to the inside of left side rail  46  approximately mid way between pivot pin  57  and bottom cross rail  48 . Left frame link  15  is pivotally connected at its upper end by a pivot pin  62  to the inside of and at the lower end of left side rail  20 . Likewise, right frame link  16  is pivotally connected at its lower end by pivot pin  59  to the inside of right side rail  47  approximately mid way between pivot pin  57  and bottom cross rail  48 , and is pivotally connected at its upper end by a pivot pin  60  to the inside of and at the lower end of right side rail  21 . 
     Pivot pins  57 - 62  may be comprised of any suitable device which holds one element together for rotation relative to another element. For example, pivot pins  57 - 62  may comprise screw and nut combinations or rivets. Pivot pins  57  are coaxial; pivot pins  58  are coaxial; pivot pins  59  and  61  are coaxial and pivot pins  60  and  62  are coaxial. 
     Flexible support  17  is comprised of any appropriate flexible material that will be strong enough to support a person sitting thereon. For example, the material may be a textile or a synthetic material. The material forming support  17  is essentially a band, each end of which is looped around and stitched back upon itself at  65  and  66  to form back loop  67  and seat loop  68 . 
     In assembly, screws  24  are removed and top cross rail  22  is separated from side rails  20  and  21 . Top cross rail  22  is slid through back loop  67 , and top cross rail  22  is then reconnected to side rails  20  and  21  and secured thereto with screws  24 . Support  17  is passed below cross bar  28 , and is similarly connected to first leg frame  13  by passing detached front cross rail  45  through seat loop  68  and then resecuring front cross rail  45  back to first leg frame  13  with screws  49 . Flexible support  17  is applied to back frame  12  and leg frame  13  typically with chair  10  in the mid-fold condition shown in FIG. 4 so that there will be ample play in flexible support  17 . 
     Top cross rail  22  and front cross rail  45  are also provided with end caps  70 . End caps  27 ,  39 ,  52 ,  53 , and  70  may be made of any material which appropriately closes off and protects the ends of the corresponding tubular or solid member. Alternative embodiments are contemplated where the tubular members would be closed off and protected from damage and protect the user from injury by means other than application of an end cap. For example, the ends could be formed in a rounded, closed-off condition, free of sharp edges. End caps  30 ,  31 ,  54 , and  55  should be comprised of a material which at a minimum reduces the possibility of damage due to repeated contact between frame links  15  and  16  and leg frame  14  and between back frame  12  and first leg frame  13 , when those components come in contact with each other as described herein. It is preferable that end caps  30 ,  31 ,  54 , and  55  have some degree of resilience to further cushion the impact between the corresponding components. Such end caps may be comprised of a plastic or rubber material. All of the aforedescribed end caps are connected to their respective components by any appropriate means such as by screws or pressure fitting or adhesive. End caps  27 ,  39 ,  52 ,  53 , and  70  do not need to have the same cushioning characteristics that are desired for end caps  30 ,  31 ,  54 , and  55 . 
     In use, chair  10  has an erected, rest condition as shown in FIGS. 1 and 2 whereby the angle  73  formed between first leg frame  13  and second leg frame  14  is just less than its maximum erected angle, and end caps  30  and  31  are not in contact with their corresponding leg frame  13  and end caps  54  and  55  are not in contact with their corresponding leg frame  14 . In one embodiment, angle  73  in the erected, rest position is approximately 98 degrees. When a person of sufficient weight sits in chair  10  (FIG.  5 ), chair  10  folds to its erected, stressed condition whereby frame members  13  and  14  spread apart a few degrees further, angle  73  thereby increases to approximately 104 degrees, and end caps  30  and  31  and  54  and  55  come into contact with their corresponding and respective leg frames  13  and  14 , as shown. (As used herein, “folds” or “folding” refers to the synergistic pivoting of the frames and links of chair  10  among the fully folded condition (FIG.  6 ), the erected, rest condition (FIG. 1) and the erected, stressed condition (FIG.  5 )). Chair  10  is limited from pivoting beyond the erected, stressed condition shown in FIG. 5 by the engagement of frame links  15  and  16  against the underside of second leg frame  14  and the engagement of the lower ends of side rails  20  and  21  against side rails  46  and  47 , respectively. The particular dimensions of the frames and links of chair  10  are chosen in connection with the length of flexible support  17  from loop  67  to loop  68 , and in connection with the location of cross bar  28  secured to back frame  12 , so that flexible support  17  will be very taut from top cross rail  22 , passing below cross bar  28 , and to front cross rail  45  when chair  10  is in the erected, stressed condition. Thus, when the person rises from seat  10 , the tension of flexible support  17  pulls seat  10  back from the erected, stressed condition (FIG. 5) to the erected, rest condition (FIG.  1 ). Seat  10  may then be folded from the erected, rest condition (FIG. 1) by pulling front cross rail  45  towards top cross rail  22 , whereby the components of chair  10  pivot relative to each other through the mid-fold condition (FIG. 4) and ultimately to the collapsed condition as shown in FIG.  6 . In the collapsed condition (FIG.  6 ), the components (frames  12 - 14  and links  15  and  16 ) have assumed a stacked configuration that is only slightly taller than the tallest component (e.g. back frame  12  or second leg frame  14 ) and is very narrow, as well. This makes chair  10  convenient to store and transport. 
     The present invention contemplates that the angle  73  formed between first and second leg frames  13  and  14  about pivot pins  57  preferably in the erected, rest condition (FIG. 1) be about 98 degrees and in the collapsed condition (FIG. 6) be about 10 degrees. However, these angles  73  may vary with the particular dimensions of the various components of chair  10  and with the particular pivotal connection locations of the various components of chair  10 . 
     Alternate embodiments are contemplated wherein second leg frame  14  and frame links  15  and  16  are pivotally secured to the outside of, instead of to the inside of, back frame  12  and first leg frame  13 . 
     FIGS. 7-10 show alternative embodiments contemplated by the present invention. Referring to FIGS. 2 and 7, first leg frame  13  is essentially shortened with its lower portion removed up to pivot pin  61  to form a generally U-shaped member  76 , and left and right frame links  15  and  16  are extended down to the ground and into a U-shaped member  78 . FIG. 8 shows diagrammatically the embodiment of FIG. 2 but with flexible support  17  shown in a sling configuration without the use of horizontal crossbar  28 . 
     FIGS. 9 and 10 show alternative embodiments where only one pair of stop members is used to define the opening limits of chair  10 . That is, referring to FIG. 9, only back frame  12  is extended far enough below pivot pins  60  and  62  to engage with first leg frame  13  to define the opening limit of chair  10  at the erected, stressed condition. The upper portion of left and right frame links  15  and  16  are shortened and do not engage with second leg frame  14 . Likewise in FIG. 10, only left and right frame links  15  and  16  engage with second leg frame  14  to define the opening limit of chair  10  and the lower portions of back frame  12  are shortened and do not engage with first leg frame  13 . 
     Back frame  12  has been described as a three piece unit. Alternative embodiments are contemplated wherein back frame  12  is a single-piece, U-shaped frame, similar to second leg frame  14 , or is yet another configuration or construction that is pivotally connected, as described herein, to leg frame  14  and frame links  15  and  16 . In such case, flexible support  17  may be made the same, which would make removal/repair thereof difficult; or flexible support  17  may be made in an alternative configuration, facilitating its removal from back frame  12  without disassembling any of the frame elements of chair  10 . For example, but in no way limiting, support  17  may be connected with either or both top and front cross rails  22  and  45 , respectively, by appropriate connectors such as snaps, wires, chains, ropes, or any other device that sufficiently securely connects support  17  to cross rails  22  and  45  and permits its ready detachment, as desired. Likewise, the present invention contemplates leg frames  13  and  14  being of alternative constructions comprising one, two, three or more components. 
     It is further contemplated that frame links  15  and  16  could comprise a single frame link having a U-shaped, box-shaped, or other appropriate configuration, but still pivotally connecting the left and right side rails of the second leg frame with the corresponding left and right side rails of the lower back frame, as described herein. 
     The present invention further contemplates a construction of chair  10  where chair  10  is folded directly to a fully erected condition wherein end caps  30  and  31  and  54  and  55  are engaged with their corresponding and respective leg frame  13  and  14 , as shown in FIG.  5 . That is, the fully erected condition is achieved without the need for a person to sit in chair  10 , but simply by folding chair  10  thereto. 
     Referring to FIG. 11, there is shown a folding chair  110  in accordance with an alternative embodiment of the present invention. Chair  110  is similar to the chair  10  of FIG. 1 except that chair  110  is larger and intended to accommodate two or more people. Where chair  10  includes back frame  12 , first leg frame  13 , second leg frame  14 , left frame link  15 , right frame link  16 , and flexible support  17 , chair  110  includes back frame  112 , first leg frame  113 , second leg frame  114 , frame links  115 , and flexible support  117 . Back frame  112  includes a pair of left side rails  120  and  121 , a pair of right side rails  122  and  123  and a pair of top cross rails  124  and  125 . Rails  120 - 125  are all arranged in a common plane and in abutting side-by-side pairs, as shown. The outer rails  120  and  122  extend up through holes (at  128 ) in top cross rails  124  and  125 , while the tops of the inner rails  121  and  123  butt up against the underside of lower top cross rail  125 . Back frame  112  further includes a central back link comprising three spacer links  129  that lie in the same plane with rails  120 - 125 . The pair of side rails  120  and  121  (and likewise the pair of rails  122  and  123  and/or the pair of rails  124  and  125  and/or the three links  129 ) could comprise a single member made in a shape and of a material to exhibit sufficient strength to tolerate the loads subjected to chair  110 . Alternatively, side rails  120 - 123  and top rails  124  and  125  are contemplated to comprise one or more pieces, assembled and appropriately connected together, to make the back frame  112  substantially as shown, ready to receive flexible support  117  and strong enough to tolerate the loads subjected to chair  110 . 
     Second leg frame  114  comprises two, U-shaped leg frames  132  and  133 , each substantially identical to the single leg frame  14  of chair  10 . It is contemplated that second leg frame  114  could comprise a one-piece leg frame instead of the two frames  132  and  133 . For example, the upper ends  130  and  131  of the inner rails of leg frames  132  and  133  may be rigidly, and perhaps integrally joined, either above spacer links  129  or as a part of their connection to spacer links  129 . 
     First leg frame  113  is similar to first leg frame  13 , except that it comprises two U-shaped tubular leg frames  134  and  135 . The top ends of the four side rails  138 - 139  and  140 - 141  of frames  134  and  135 , respectively, are rigidly, but removably connected to a front cross rail  136 . As with chair  10 , top cross rails  124  and  135  and front cross rail  136  are detachable from their respective side rails to facilitate the [application] assembly, repair and maintenance of flexible support  17 . First leg frame  113  further includes left and right outer stop members  144  and  145  and leg spacer member  146 . Outer stop members  144  and  145  are rigidly connected to the outsides of outer rails  138  and  141 , respectively, and are positioned to provide, along with outer rails  138  and  141 , stop surfaces for the bottom ends of side rails  120 - 123 . Leg spacer member  146  is fixedly connected between and against the center side rails  139  and  140 , as shown in FIG.  11 . 
     As with chair  10  of FIG. 1 where there are two frame links  15  and  16  connected to the opposing side rails of the first and second leg frames  13  and  14 , chair  110  includes frame links  115  that are connected in a substantially similar manner to the side rails of the first and second leg frames  113  and  114 . In the embodiment of FIG. 11, there are two such frame links  142  and  143  that differ from the frame links  15  and  16  of chair  10  by the addition of a cross member at their bottom ends. Thus, frame link  142  is U-shaped having opposing left and right frame link members  148  and  149  (for pivotal connection with side rails  138  and  139 ), and link  143  is U-shaped having opposing left and right frame link members having  150  and  151  (for pivotal connection with side rails  140  and  141 ). Frame link members  148  and  149  are joined at their bottom ends by a frame link cross member  152 , and frame link members  150  and  151  are joined at their bottom ends by a frame link cross member and  153 . Alternatively, and for additional stability, the two frame links  142  and  143  are contemplated to be connected to each other by a common bottom cross member, configured to rigidly join all four of the frame link members  148 - 151  together without interfering with the folding and unfolding action and limits of chair  110 . 
     The back frame  112 , first leg frame  113 , second leg frame  114  and frame links  115  are operatively interconnected by various pivot pins ( 155 - 166 , for example) in a manner substantially the same as the back frame  12 , first leg frame  13 , second leg frame  14  and frame links  15  of chair  10 . Pins connecting like pivot points are coaxially aligned. For example, in coaxial alignment along a first pivot axis  171  are pin  155  (pivotally connecting right side rails  122  and  123  with the top end  168  of the right rail of leg frame  133 ), pin  156  (pivotally connecting the top end  130  of right leg frame  133  with the top end  131  of left leg frame  132  and with the top ends of spacer links  129  therebetween), and pin  157  (pivotally connecting left side rails  120  and  121  with the top end  169  of the left rail of leg frame  132 ). And in coaxial alignment along a third pivot axis  173  are pin  158  (connecting the lower ends of rails  122  and  123  with frame link  151 ), pin  159  (connecting frame link  150  with frame link  149  and with the lower ends of spacer links  129 ), and pin  160  (connecting frame link  148  with left side rails  120  and  121 ). 
     In alignment along a second pivot axis  172  are pin  161  (connecting outer stop member  145  to side rail  141  and pivotally to the right rail of leg frame  133 ), pin  162  (connecting the left rail of leg frame  133  with rails  140  and  139  and leg spacer member  146 , and with the right side rail of leg frame  132 ), and pin  163  (connecting the left rail of leg frame  132  with rail  138  and outer stop member  144 ). 
     In alignment along a fourth pivot axis  174  are pin  164  (connecting outer stop member  145  to side rail  141  and pivotally to right frame link  151 ), pin  165  (connecting left frame link  150  with rails  140  and  139  and leg spacer member  146 , and with right frame link  149 ), and pin  166  (connecting left frame link  148  with rail  138  and outer stop member  144 ). 
     The upper ends of center side rails  139  and  140  are received within complementary shaped holes (not shown) in cross rail  136  and secured thereat by appropriate means such as screws, adhesive or pressure fit. Flexible support  117  is provided with openings (not shown) at the juncture of rails  139  and  140  with cross rail  136 , and chair is there assembled by first positioning support  117  appropriately so that the openings in support  117  are aligned with the holes in cross rail  136 , and then by inserting the ends of rails  139  and  140  through the holes in flexible support  117  and into the holes in cross rail  136 . 
     In operation and use, chair  110  works substantially the same as chair  10  and has substantially the same profile as chair  10  in FIG.  6 . One notable exception is that the frame links  148 - 151  and cross members  152  and  153  extend upwardly a short distance more than the frame links  15  and  16 . 
     Referring to FIGS. 12 and 13, there is shown a folding chair  180  in accordance with an alternative embodiment of the present invention. Chair  180  is similar to the chair  10  of FIG. 1 and, in addition, adds multiple articulating links  181  to provide a higher sitting height, as in a director&#39;s chair. Chair  180  has the very flat folded configuration shown in FIG.  13 . 
     Leg frames  113  and  114  and frame links  115  all include U-shaped frames; however, other embodiments contemplate alternative configurations. For example, instead of cross member  153  extending between the opposing frame link members  150  and  151 , cross member  153  could be located midway up to form an H-shaped frame link, or it could comprise two cross members to form an X-shaped member between frame link members  150  and  151 . 
     In an alternative embodiment shown in FIG. 14, chair  182  is substantially the same as chair  110  of FIG. 11, except that instead of the U-shaped frame links  142  and  143 , frame links are provided that are similar to the frame links  15  and  16  of the chair of FIG.  1  and comprise a total of four, short frame links  148   a,    149   a,    150   a  and  151   a  with no interconnecting frame link cross members  152  and  153 . The short frame links  148   a - 151   a  are operatively pivotally connected by the same pivot pins  158 - 160  and  164 - 166  to back frame  112  and first and second leg frames  113  and  114 . Additional structural stability is provided by a lower cross bar  154  that extends across the backside of and is secured to back frame  112  and spacer links  129 , as shown. Further stability may be afforded by using larger dimensional members, or members having different shapes and compositions, or by adding additional members. For example, one embodiment includes using two cross bars  183  and  184 , one above the other, on the back side of back frame  112  and under which extends flexible support  117 . 
     Referring to FIG. 15, there is shown a folding chair  185  in accordance with another embodiment of the present invention. Chair  185  is similar to the chair  10  of FIG.  1  and in addition, includes outer support links  186  and  187  and third and fourth leg frames  188  and  189 , respectively. Left and right frame links  15  and  16  are pivotally connected to back frame  12  and first leg frame  13 . Fourth leg frame  189  is U-shaped and pivotally connected to the lower end of first leg frame  13  at the pivot pins  59  and  61  that connect frame links  15  and  16  to first leg frame  13 . Third leg frame  188  is pivotally connected to second leg frame  14  by pivot pins  190  and  191 . Third leg frame  188  is pivotally connected to fourth leg frame  189  at pivot pins  192  and  193 , respectively. Outer support links  186  and  187  are pivotally connected at their upper ends with back frame  12  and second leg frame  14  at the pivot pins (only one shown at  194 ). 
     Like first and second leg frames  13  and  14 , third and fourth leg frames  188  and  189  each have left and right side rails that have axes. Assembled as shown in FIG. 15, the axes of the following pairs are substantially coplanar: left frame link  15  and outer support link  186 ; right frame link  16  and outer support  187 ; the corresponding left and right side rails of back frame  12 , of first leg frame  13  and of third leg frame  188 ; and, the corresponding left and right side rails of second leg frame  14  and of fourth leg frame  189 . The adaptation of folding chair  10  to folding  185  is further modified by removing the bottom cross rail  48  from first leg frame  13 . The bottom cross rail  38  of second leg frame  14  is kept to provide a foot rest for the user. 
     FIGS. 16-18 show folding chair  185  in successive stages as it is folded from its erected, rest condition of FIG. 15 to its collapsed condition shown in FIG.  18 . 
     The outer support links  186  and  187  are parallel to the side rails  36  and  37  of second leg frame  14  and are joined to respective side rails  36  and  37  at two places: at the their upper ends (only one shown at  194 ) and at their lower ends at  190  and  191 . As a consequence, outer support links  186  and  187  are substantially immovable relative to second leg frame  14 , and outer support link  186  is considered to be an operational part of left side rail  36 , and outer support link  187  is considered to be an operational part of right side rail  37 . In the chair  10  of FIG. 1, the left and right frame links  15  and  16  are connected to the insides of the side rails of back frame  12  and first leg frame  13 , while in the chair  185  of FIG. 15, the frame links  15  and  16  are connected to the outsides of such side rails. This is so that fourth frame leg  189  can be connected to the insides of the side rails of both first and third leg frames  13  and  188 . The axes of left and right frame links  15  and  16  are coplanar with the axes of the corresponding outer support links  186  and  187 , respectively, and are therefore still considered to be coplanar with the side rails of second leg frame  14 . 
     Viewed another way, an alternative, but substantially identical embodiment contemplates the bottom cross rail  38  extending across the bottoms of outer support links  186  and  187  instead of across the bottoms of left and right side rails  36  and  37 . Side rails  36  and  37  would then simply extend between their pivotal connections at upper pivot pins (one shown at  194 ) and lower pivot pins  190  and  191 , just as support links  186  and  187  do in the chair of FIG.  15 . The combination of links  186  and  187  and rails  36  and  37  act as a unit and have axes (in links  186  and  187 ) that are co-planar with the axes of links  15  and  16 . 
     As used herein, leg frames, such as leg frames  132  and  133  of FIG. 14, are described as being U-shaped. It is contemplated that such “U-shaped” description includes other shapes, for example an H-shape, it being important that there be the described side rails to pivotally connect with other side rails and links so that the chair may fold as described and shown. The various cross members extending between the side rails are primarily for structural stability, and other configurations, such as an H-shape or X-shape or other structurally sound shapes, are contemplated within the meaning of “U-shape.” While the invention has been described in detail in the foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described, and that all changes and modifications that come within the spirit of the invention are desired to be protected.