Patent Publication Number: US-6702371-B2

Title: Foldable chair with detachable seat arrangement

Description:
BACKGROUND OF THE PRESENT INVENTION 
     1. Field of Invention 
     The present invention relates to a chair, and more particularly to a foldable chair with detachable seat arrangement which is capable of supporting the weight of the users. 
     2. Description of Related Arts 
     Foldable chairs are widely used all over the world. People often use foldable chair in outdoors environment such as in beaches or in campsites in that they are portable and usually foldable. 
     Referring to FIG. 1 of the drawings, usually a conventional foldable chair comprises a chair frame A 1  and a seat fabric B 1 . The chair frame A 1  comprises a plurality of construction bars C 1  pivotally connected together to form a back supporting frame A 11  and a seat supporting frame A 12  for supporting the seat fabric B 1 . The seat supporting frame comprises a front pair, a back pair, and two pairs of construction bars C 1 , wherein each pair of construction bars are pivotally connected together to form a pivotal ‘X’ structure. 
     The seat fabric B 1  has a seat portion B 11  and a back supporting potion B 12 , wherein the seat fabric B 1  is slidably and suspendedly attached onto the chair frame A 1  so as to provide a seat to the users. 
     However, such a conventional foldable chair possesses some significant drawbacks. First of all, since the fabric seat B 1  is suspendedly supported by the chair frame, and the fabric by itself is soft and can be folded or squeezed into irregular shape, the seat fabric may not be substantially supported by the chair frame A 1  due to small supporting surface area. From simple physical analysis, one can easily expect that when a person sits onto the seat portion of the seat fabric B 1 , the seat fabric B 1  will easily be stretched toward the central part of the seat portion and the person sitting thereon will tend to plunge into the central part of the seat portion. This usually makes the person sitting thereon difficult to move and feel uncomfortable or insecure. 
     In terms of the ways in which the seat fabric is supported, as shown in FIG. 1, only point support is provided to the seat fabric B 1 . The seat portion of the seat fabric is supported by a pair of supporting joints A 13  positioned near the front side corners of the seat fabric. When the person sits onto the seat fabric B 1 , the weight of the user tries to pull the edges of the seat fabric B 1  toward the central portion thereof, and therefore stress will be induced and substantially concentrated at the joints that suspendedly support the seat fabric B 1 . As a result, after a considerable period of time, the joints may be distorted or more seriously, broken, and this can bring disastrous consequence to the user. 
     Moreover, the seat fabric B 1  is permanently attached onto the chair frame A 1 . Because the foldable chair is usually used in outdoors environment, after a period of time, the seat fabric B 1  will be dirty and need cleaning. However, sometimes the user is hard or even unable to detach the seat fabric for cleaning purpose. 
     Last but not least, for the chair to be compactly foldable, one shouldn&#39;t attach any bulky accessory, such as a seating cushion onto the chair. Therefore, conventionally, the seating portion of the chair is usually made of fabric and in simple structure, thus making the chair uncomfortable. From another point&#39;s of view, the seat fabric B 1  of the foldable chair plays an important role for the compactness thereof. Thus, in other words, the simpler the seat fabric is, the more compact the chair can fold. A detachable seat may be needed to solve this problem. 
     SUMMARY OF THE PRESENT INVENTION 
     A main object of the present invention is to provide a foldable chair with detachable seat arrangement, wherein the user&#39;s body can be substantially supported so that the foldable chair is more comfortable to the user as compare with conventional foldable chairs. 
     Another object of the present invention is to provide a foldable chair with detachable seat arrangement wherein line support is provided for supporting the seat fabric, so as to minimize the stretching and distortion of the seat fabric when the user is sat onto the foldable chair. 
     Another object of the present invention is to provide a foldable chair with detachable seat arrangement wherein the seat fabric can be detached from and attached onto the chair frame without involving any complicated mechanical procedure. 
     Another object of the present invention is to provide a foldable chair with detachable seat arrangement wherein the chair frame and the seat supporting frame are capable of individually folding into compact size so as to facilitate easy and convenient carrying and storage. 
     Another object of the present invention is to provide a foldable chair with detachable seat arrangement which does not require to significantly alter the original structure and shape of a conventional foldable chair, so as to minimize the manufacturing and administrative cost of the present invention. 
     Accordingly, in order to accomplish the above objects, the present invention provides a foldable chair comprising: 
     a chair frame which comprises: 
     a front supporting frame which comprises a plurality of front frame legs pivotally coupled with each other to form a pivotal ‘X’ structure; 
     a pair of side supporting frames, wherein each side supporting frame comprises a first and a second side frame leg pivotally coupled with each other to form a pivotal ‘X’ structure; and 
     a back supporting frame which comprises a plurality of back frame legs pivotally coupled with each other to form a pivotal ‘X’ structure, and a plurality of rear supporting legs, wherein each of the rear supporting legs has an upper attaching portion; 
     a pair of front frame joints pivotally connecting two upper end portions of the front frame legs and two upper end portions of the first side frame legs respectively; and 
     a pair of back frame joints pivotally connecting two upper end portions of the back frame legs and two upper ends portions of the second side frame legs respectively, wherein the pair of rear supporting legs are upwardly extended through the pair of back frame joints respectively; 
     a seat frame which comprises: 
     a fabric supporting frame which comprises at least a seat supporting bar to define a seat portion, a back portion and a central opening of the fabric supporting frame, 
     a seat fabric which has a side edge portion substantially supported by the fabric supporting frame; and 
     a detachable seat arrangement which comprises: 
     a plurality of fabric frame holders provided at the upper attaching portions of the rear supporting frames respectively for detachably mounting the fabric supporting frame on the back supporting frame; and 
     a pair of securing members provided on the seat frame for detachably mounting the fabric supporting frame onto the front supporting frame, so as to secure the seat frame on the chair frame in a detachable manner. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a conventional foldable chair. 
     FIG. 2 is a perspective view of a foldable chair with detachable seat arrangement according to a first preferred embodiment of the present invention. 
     FIG. 3 is an exploded perspective view of the foldable chair with detachable seat arrangment according to the first preferred embodiment of the present invention, illustrating that the seat frame is detached from the chair frame. 
     FIG. 4 is a perspective view of the fabric frame holder of the foldable chair according to the above first preferred embodiment of the present invention. 
     FIG. 5 is a front view of the foldable chair according to the above first preferred embodiment of the present invention, illustrating that the seat frame is mounted onto the chair frame by means of the securing members. 
     FIG  6  is a first alternative mode of the detachable seat arrangement of the foldable chair according to the above first preferred embodiment of the present invention. 
     FIG. 7 is a second alternative mode of the detachable seat arrangement of the foldable chair according to the above first preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 2 to  3  of the drawings, a foldable chair  10  with detachable seat arrangement  40  according to a first preferred embodiment of the present invention is illustrated. According to the first preferred embodiment of the present invention, the foldable chair  10  comprises a chair frame  20 , a seat frame  30  inclinedly supported by the chair frame  20 , and a detachable seat arrangement  40 . 
     The chair frame  20  comprises a front supporting frame  21 , a pair of side supporting frames  22 , and a back supporting frame  23 . The front supporting frame  21  comprises a plurality of front frame legs  211  pivotally coupled with each other to form a pivotal ‘X’ structure. Each of the side supporting frames  22  comprises a first and a second side frame leg  221 ,  222  pivotally coupled with each other to form a pivotal ‘X’ structure. The back supporting frame  23  comprises a pair of back frame legs  231  pivotally coupled with each other to form a pivotal ‘X’ structure, and a pair of rear supporting legs  232  each having an upper attaching portion  2321 . 
     The chair frame  20  further comprises a pair of front frame joints  24  and a pair of back frame joints  25 , wherein the front frame joints  24  are pivotally connected with two upper end portions of the two front frame legs  211  and two upper end portions of the first side frame legs  221  respectively, and the back frame joints  25  are pivotally connected with the two upper end portions of the back frame legs  231  and the upper end portions of the second side frame legs  222  respectively. 
     The chair frame  20  further comprises four base joints  261 ,  262 ,  263 ,  264 . The first and the second base joint  261 ,  262  are pivotally connected with the lower end portions of the front frame legs  211  and the lower end portions of the first side frame legs  221  respectively, whereas the third and the fourth base joints  263 ,  264  are pivotally connected with the lower end portions of the back frame legs  231  and the lower end portions of the second side frame legs  222  respectively. Moreover, the lower end portions of the rear supporting legs  232  are connected to the third and the fourth base joints  263 ,  264  respectively. 
     The pair of rear supporting legs  232  is upwardly extended from the third and the fourth base joints  263 ,  264  and slidably pass through the pair of back frame joints  25  respectively so as to provide support to the seat frame  30  and the detachable seat arrangement  40 . 
     The seat frame  30  comprises a fabric supporting frame  31  and a seat fabric  32  supported thereon. According to the first preferred embodiment of the present invention, the fabric supporting frame  31  comprises a pair of semi-circular seat supporting bars  311  pivotally and foldably connected together in an end-to-end manner so as to form a complete fabric supporting frame  31  having a fabric supporting portion  312  and a frame connecting portion  313 . Thus, the fabric supporting frame  31  is circular in shape having a central opening  314  for supporting a main portion of the seat fabric  32  therein. 
     The seat fabric  32  is supported by the fabric supporting frame in such a manner that an edge portion of the seat fabric  32  is mounted along the fabric supporting portion  312  of the fabric supporting frame  31 . Thus, the seat fabric  32  is substantially supported by the fabric supporting frame  31 . Moreover, the above structural arrangement provides line support to the seat fabric  32  so that any downward loading exerted thereon, such as the weights of the users, is capable of being evenly distributed along the seat supporting bars  311 . 
     The edge portion of the seat fabric  32  has two tubular and elongated holding sleeves  323  formed thereon, wherein each of the holding sleeve  323  has an elongated receiving cavity  3231  for one of the seat supporting bars  311  passing through and being received therein. 
     Accordingly, the fabric supporting portion  312  of the fabric supporting frame  31  is the portion of the seat supporting bar  311  that is received inside the holding sleeves  323 . Similarly, the frame connecting portion  313  is the portion of the seat supporting bar  311  that is not received inside the holding sleeves  323 . 
     With the edge portion substantially supported by the fabric supporting frame  31 , a main portion of the seat fabric  32  is suspendedly supported inside the central opening  314 . The main potion of the seat fabric  32  is divided into a seat portion  321  for mainly supporting the user&#39;s hip and thigh, and a back supporting potion  322  for mainly supporting the user&#39;s trunk. 
     Referring to FIG. 4 of the drawings, the detachable seat arrangement  40  is comprises a pair of fabric frame holders  41  securely mounted on the upper attaching portions  2321  of the rear supporting legs  232  respectively, and a pair of securing members  42  provided at the seat portion  321  of the seat fabric  32  for detachably mounting the fabric supporting frame  31  onto the front supporting frame  21 . 
     Each of the fabric frame holders  41  has an top inclined surface and two side walls upwardly extended therefrom to define an engaging slot  411  for engaging with the frame connecting portions  313  of the fabric supporting frame  31 . The orientation of the engaging slots  411  are substantially aligned with the frame connecting portions  313  of the fabric supporting frame  31  respectively, so that they are capable of fittedly engaging with the engaging slots  411  formed on the fabric frame holders  41  respectively. 
     Referring to FIG. 5 of the drawings, the front frame legs  211  are upwardly protruded through the two front frame joints  24  to form two respective protruding portions of the front frame legs  211 . According to the first preferred embodiment, the securing members  42  are essentially two fabric-made securing wings securely attached on the bottom surface of the seat fabric  32 , wherein each of the fabric-made securing wings has a through securing ring  421  formed thereon. The protruding portions of the front frame legs  211  are arranged to pass through the through securing rings  421  respectively so as to detachably hold the seat portion  321  of the seat fabric  32  in position. In other words, the fabric supporting frame  31  are securely held in position by the pair of the fabric frame holders  41  and the pair of the securing members  42 , wherein the fabric frame holders  41  keep the back supporting portion  322  of the seat fabric  32  in position and the securing members  42  keep the seat portion  321  of the seat fabric  32  in position. 
     It is worth to mention that the height of the frame supporting holders  41  should be greater than the height of the pair of the protruding portions of the front frame legs  211  so that the seat frame  30  is inclinedly supported by the chair frame  20 . 
     Referring to FIG. 3 of the drawings, the seat frame  30  further comprises a plurality of reinforcing holders  33  provided on the edge portion of the seat fabric  32  for further enhancing the mounting strength between the seat fabric  32  and the fabric supporting frame  31 . Each of the reinforcing holders  33  has two ends affixed onto the top and bottom surface of the seat fabric  32  respectively so as to define a holding cavity  331  for holding one of the seat supporting bars  311  and the edge portion of the seat fabric  32 . 
     Referring to the FIG. 5 of the drawings, the seat frame  30  further comprises a strengthening member  34  provided at the bottom surface of the seat fabric  32  and connecting the two securing members  42 . The strengthening member  34  is fabric-made and affixed to bottom surface of the seat fabric  32  so as to provide additional support to the seat portion  321  of the seat fabric  32 , so that the user&#39;s hip and thigh will feel more comfortable and secure when he/she sits on the foldable chair of the present invention. 
     To attach the seat frame  30  onto the chair frame  20 , a user has first to unfold the chair frame  20 , and unfold the pair of seat supporting bars  311  into a complete circular fabric supporting frame  31 . Then, the user has to mount the seat frame  30  into the chair frame  20  by engaging the frame connecting portion  313  of the fabric supporting frame  31  with the engaging slots  411  of the fabric frame holders  41 , and affixing the pair of securing members  42  to the protruding portions of the front frame legs  211  through the through securing rings  421  respectively. Conversely, to detach the seat frame  30  from the chair frame  20 , the user has to detach the pair of securing members  42  from the front frame legs  211 , and then to disengage the fabric supporting frame  31  from the fabric frame holders  41 . Finally, the user should fold up the foldable chair frame  20  as well as the fabric supporting frame  31 . 
     Note that by detaching the seat frame  30  from the foldable chair frame  20 , the users of the present invention can be able to carry the foldable chair  10  conveniently in that the seat frame  30  as well as the chair frame  20  are capable of being folded into a compact size. 
     Also, it is important to remark that the fabric supporting frame  31  can be constructed to any reasonable shape such as a rectangular shape or a square shape, instead of the circular shape as mentioned above, as long as the fabric supporting frame  31  is capable of providing line support to the seat fabric mounted thereon. 
     Referring to FIG. 6 of the drawings, an alternative mode of the detachable seat arrangement  40 ′ according to the first preferred embodiment of the present invention is illustrated. According to the first alternative mode, instead of penetrating the front frame joints  24  by the front frame legs  211  respectively, the first side frame legs  221 ′ are upwardly extended from the pair of front frame joints  24 ′ to define the two protruding portions of the two first side frame legs  221 ′ respectively. The securing members  42 ′ affixed on the seat fabric  32 ′ are then arranged for mounting onto the protruding portions of the first side frame legs respectively, as shown in FIG.  8 . 
     Referring to FIG. 7 of the drawings, a second alternative mode of the detachable seat arrangement  40 ″ according to the first preferred embodiment of the present invention is illustrated. The second alternative mode is similar to that of the first preferred embodiment except the detachable seat arrangement  40 . According to the second alternative mode, each of the securing members  42 ″ comprises a seat securing holder  44 ″ having one end mounted onto the protruding portions of the front frame legs  211 ″ and another end mounted on the fabric supporting frame  31 ″. Each of the seat securing holders  44 ″ has an holding slot  441 ″ formed thereon for detachably engaging with the seat supporting bars  311 ″ of the fabric supporting frame  31 ″. The orientation of the holding slot  441 ″ is made to well-aligned with the seat supporting bars  311 ″ for fittedly engaging the securing holders  44 ″ onto the seat frame  30 ″. Accordingly, the fabric supporting frame  31 ″ is capable of engaging and disengaging with the fabric frame holders  41 ″ and the seat supporting holders  44 ″, so as to detachably mount the seat frame  30 ″ on to the chair frame  20 ″. 
     It is worth to mention that in addition to the seat fabric  30  for seating purpose, one can freely put a foldable cushion on top of the seat fabric in order to enhance the comfort of the foldable chair  10  of the present invention.