Abstract:
A chair assembly includes a first support stand, a second support stand, a support frame, four support tubes, four connecting members, two first mounting members, two elastic members, and two second mounting members. Thus, the chair assembly can be folded and expanded easily and conveniently. In addition, the chair assembly can be supported rigidly and stably.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a chair assembly, and more particularly to a chair assembly that can be folded and expanded easily and conveniently. 
     2. Description of the Related Art 
     A conventional fixed chair forms a rigid and stable support to the user, so that the user can be seated on the chair comfortably. However, the conventional fixed chair has a fixed volume and cannot be folded, thereby causing inconvenience to the user where carrying storing the chair. In addition, the conventional fixed chair has a fixed size and cannot be folded, thereby occupying larger space when not in use. A conventional foldable chair can be expanded when in use and can be folded when not in use so as to save the space, thereby facilitating the user carrying and storing the conventional foldable chair. However, the conventional foldable chair tends to be folded unintentionally, thereby causing danger to the user. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a chair assembly that can be folded and expanded easily and conveniently. 
     Another objective of the present invention it to provide a chair assembly that can be supported rigidly and stably. 
     In accordance with the present invention, there is provided a chair assembly, comprising a first support stand, a second support stand, a support frame, four support tubes, four connecting members, two first mounting members, two elastic members, and two second mounting members, wherein: 
     the first support stand has two opposite sides each having a distal end formed with a through hole; 
     the second support stand has two opposite sides pivotally connected with the two opposite sides of the first support stand; 
     the support frame is mounted on the first support stand and the second support stand and has a periphery formed with four insertion holes; 
     each of the four support tubes is secured in a respective one of the four insertion holes of the support frame and has an inner wall formed with a screw bore; 
     each of the four connecting members is secured on a respective one of the four support tubes and has a first end formed with a threaded rod screwed into the screw bore of a respective one of the four support tubes and a second end formed with a pivot portion formed with a pivot hole; 
     each of the two first mounting members is movably mounted on the distal end of a respective one of the two opposite sides of the first support stand and is pivotally connected with a respective one of the four connecting members; 
     each of the two first mounting members has a wall formed with a positioning hole aligning with the through hole of the first support stand; 
     each of the two elastic members is mounted in the distal end of a respective one of the two opposite sides of the first support stand and has an end formed with a positioning snap extended through the through hole of the first support stand and protruded outward from the positioning hole of a respective one of the two first mounting members, so that each of the two first mounting members is secured on the distal end of a respective one of the two opposite sides of the first support stand by the positioning snap of the elastic member; and 
     each of the two second mounting members is secured on the distal end of a respective one of the two opposite sides of the second support stand and is pivotally connected with a respective one of the four connecting members. 
     Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of a chair assembly in accordance with the preferred embodiment of the present invention; 
     FIG. 1A is a partially enlarged view of the chair assembly as shown in FIG. 1; 
     FIG. 2 is a perspective view of the chair assembly in accordance with the preferred embodiment of the present invention; 
     FIG. 2A is a partially enlarged view of the chair assembly as shown in FIG. 2; 
     FIG. 2B is a partially enlarged view of the chair assembly as shown in FIG. 2; 
     FIG. 3 is a plan view of the chair assembly in accordance with the preferred embodiment of the present invention; 
     FIG. 3A is a partially enlarged cross-sectional view of the chair assembly as shown in FIG. 3; 
     FIG. 3B is a partially enlarged cross-sectional view of the chair assembly as shown in FIG. 3; 
     FIG. 4 is a schematic operational view of the chair assembly as shown in FIG. 3; 
     FIG. 4A is a schematic operational view of the chair assembly as shown in FIG. 4; and 
     FIG. 4B is a schematic operational view of the chair assembly as shown in FIG.  4 A. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and initially to FIGS. 1-3, a chair assembly  8  in accordance with the preferred embodiment of the present invention comprises a first support stand  1 , a second support stand  2 , a support frame  3 , four support tubes  4 , four connecting members  6 , two first mounting members  5 , and two second mounting members  7 . 
     The first support stand  1  is substantially U-shaped and has two opposite sides each having a distal end formed with a through hole  11  (see FIG.  1 A). 
     The second support stand  2  is substantially U-shaped and has two opposite sides pivotally connected with the two opposite sides of the first support stand  1  by two pivot pins  15 . 
     The support frame  3  is mounted on the first support stand  1  and the second support stand  2  and has a periphery formed with four insertion holes  31  (see FIG.  3 A). 
     Each of the four support tubes  4  (see FIG. 3A) is secured in a respective one of the four insertion holes  31  of the support frame  3  and has an inner wall formed with a screw bore  41 . 
     Each of the four connecting members  6  is secured on a respective one of the four support tubes  4  and has a first end formed with a threaded rod  61  screwed into the screw bore  41  of a respective one of the four support tubes  4  and a second end formed with a circular pivot portion  62  formed with a pivot hole  63 . 
     Each of the two first mounting members  5  is movably mounted on the distal end of a respective one of the two opposite sides of the first support stand  1  and is pivotally connected with a respective one of the four connecting members  6 . 
     As shown in FIGS. 1A and 2A, each of the two first mounting members  5  has a periphery formed with two spaced circular pivot ears  53  each formed with a pivot hole  531 , and the chair assembly  8  further comprises two pivot pins  54  each extended through the pivot hole  531  of each of the two pivot ears  53  of a respective one of the two first mounting members  5  and the pivot hole  63  of the pivot portion  62  of a respective one of the four connecting members  6 , so that the pivot portion  62  of the connecting member  6  is pivotally mounted between the two pivot ears  53  of the respective first mounting member  5 . 
     Each of the two first mounting members  5  has a wall  51  formed with a positioning hole  52  aligning with the through hole  11  of the first support stand  1 , and the chair assembly  8  further comprises two elastic members  13  each mounted in the distal end of a respective one of the two opposite sides of the first support stand  1  and each having an end formed with a positioning snap  14  extended through the through hole  11  of the first support stand  1  and protruded outward from the positioning hole  52  of a respective one of the two first mounting members  5  as shown in FIGS. 2A and 3A, so that each of the two first mounting members  5  is secured on the distal end of a respective one of the two opposite sides of the first support stand  1  by the positioning snap  14  of the elastic member  13 . The chair assembly further comprises two end caps  12  each removably mounted on the distal end of a respective one of the two opposite sides of the first support stand  1  to enclose the respective elastic member  13 . 
     Each of the two second mounting members  7  is secured on the distal end of a respective one of the two opposite sides of the second support stand  2  and is pivotally connected with a respective one of the four connecting members  6 . 
     As shown in FIGS. 2B and 3B, each of the two second mounting members  7  has a first end formed with two spaced circular pivot ears  71  each formed with a pivot hole  72 , and the chair assembly  8  further comprises two pivot pins  73  each extended through the pivot hole  72  of each of the two pivot ears  71  of a respective one of the two second mounting members  7  and the pivot hole  63  of the pivot portion  62  of a respective one of the four connecting members  6 , so that the pivot portion  62  of the connecting member  6  is pivotally mounted between the two pivot ears  71  of the respective second mounting member  7 . 
     In addition, each of the two second mounting members  7  has a second end formed with an insert  74  (see FIG. 3B) inserted into the distal end of a respective one of the two opposite sides of the second support stand  2 , and the chair assembly  8  further comprises two fixing pins  75  (see FIG. 3B) each extended through the distal end of a respective one of the two opposite sides of the second support stand  2  and the insert  74  of a respective one of the two second mounting members  7 , so that each of the two second mounting members  7  is secured on the distal end of a respective one of the two opposite sides of the second support stand  2 . 
     In operation, referring to FIGS. 1-4, the positioning snap  14  of each of the two elastic members  13  is protruded outward from the positioning hole  52  of a respective one of the two first mounting members  5  as shown in FIGS. 2A and 3A, so that each of the two first mounting members  5  is secured on the first support stand  1 , and the chair assembly  8  is disposed at an expanded state as shown in FIG.  3 . 
     When the user wishes to fold the chair assembly  8 , the positioning snap  14  of each of the two elastic members  13  is pressed inward as shown in FIG. 4 to detach from the positioning hole  52  of a respective one of the two first mounting members  5 , so that each of the two first mounting members  5  is detached from the first support stand  1 . Then, the support frame  3  is pressed downward, so that the first support stand  1  is pressed to move relative to the two first mounting members  5  as shown in FIG. 4A, and the second support stand  2  is pivoted with the first support stand  1 , thereby folding the chair assembly  8  as shown in FIG.  4 B. 
     Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.