Patent Publication Number: US-2004051009-A1

Title: Extensible leg frame

Description:
BACKGROUND OF THE INVENTION  
       [0001] The present invention relates to an extensible leg frame. More particularly, the present invention relates to an extensible leg frame for a table or a foldable chair.  
       [0002] Referring to FIGS. 1 and 2, a conventional extensible leg frame  1  has four leg rods  11 , four pivot joints  12 , four movable collars  13 , and eight connection rods  14 . Each pivot joint  12  is disposed on a top end of the corresponding leg rod  11 . Each movable collar  13  surrounds the corresponding leg rod  11 . Each connection rod  14  is connected to the corresponding pivot joint  12  and the corresponding movable collar  13 . However, a center of gravity of the conventional extensible leg frame  1  will be moved upward while the conventional extensible leg frame  1  is extended. Therefore, the conventional extensible leg frame  1  will stand unstably. When the conventional extensible leg frame  1  is bumped by a user, the conventional extensible leg frame  1  will be collapsed.  
       SUMMARY OF THE INVENTION  
       [0003] An object of the present invention is to provide an extensible leg frame which stands stably while the extensible leg frame is extended. A center of gravity of the extensible leg frame is lowered. When the extensible leg frame is bumped by a user, the extensible leg frame will not be collapsed easily.  
       [0004] Accordingly, an extensible leg frame comprises four support rods, four tubes, four hollow joints, four bottom seats, and eight connection rods. Each hollow joint is disposed on a top end of the corresponding support rod. Each tube is disposed on the corresponding bottom seat. Each support rod is inserted through the corresponding tube. Each connection rod is connected to the corresponding hollow joint and the corresponding bottom seat. Each support rod has a round aperture. Each hollow joint has a plurality of circular apertures. A rivet fastens the corresponding hollow joint and the corresponding support rod together. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0005]FIG. 1 is a perspective view of a conventional extensible leg frame of the prior art;  
     [0006]FIG. 2 is a schematic view illustrating a folding of a conventional extensible leg frame of the prior art;  
     [0007]FIG. 3 is a perspective view of an extensible leg frame of a first preferred embodiment in accordance with the present invention;  
     [0008]FIG. 4 is a partially perspective exploded view of an extensible leg frame of a first preferred embodiment in accordance with the present invention;  
     [0009]FIG. 5 is a sectional schematic view illustrating an operation of an extensible leg frame of a first preferred embodiment in accordance with the present invention;  
     [0010]FIG. 6 is a perspective schematic view illustrating an operation of an extensible leg frame of a first preferred embodiment in accordance with the present invention;  
     [0011]FIG. 7 is a schematic view illustrating a folding of an extensible leg frame of a first preferred embodiment in accordance with the present invention;  
     [0012]FIG. 8 is a partially sectional assembly view of an extensible leg frame of a second preferred embodiment in accordance with the present invention;  
     [0013]FIG. 9 is a partially sectional assembly view of an extensible leg frame of a third preferred embodiment in accordance with the present invention; and  
     [0014]FIG. 10 is a schematic view illustrating a chair seat disposed on an extensible leg frame of a first preferred embodiment in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0015] Referring to FIGS.  3  to  7 , a first extensible leg frame  2  comprises four support rods  21 , four tubes  230 , four hollow joints  22 , four bottom seats  23 , and eight connection rods  3 .  
     [0016] Each hollow joint  22  is disposed on a top end of the corresponding support rod  21 .  
     [0017] Each tube  230  is disposed on the corresponding bottom seat  23 .  
     [0018] Each support rod  21  is inserted through the corresponding tube  230 .  
     [0019] Each connection rod  3  is connected to the corresponding hollow joint  22  and the corresponding bottom seat  23 .  
     [0020] Each support rod  21  has a round aperture  211 .  
     [0021] Each hollow joint  22  has a plurality of circular apertures  221 .  
     [0022] A rivet  24  fastens the corresponding hollow joint  22  and the corresponding support rod  21  together.  
     [0023] Each tube  230  has a through hole  231 .  
     [0024] Referring to FIG. 8, a second extensible leg frame  2 ′ comprises at least a support rod  21 ′, at least a tube  230 ′, at least a hollow joint  22 ′, and at least a bottom seat  23 ′.  
     [0025] The hollow joint  22 ′ is disposed on a top end of the support rod  21 ′.  
     [0026] The tube  230 ′ is disposed on the bottom seat  23 ′.  
     [0027] The tube  230 ′ is inserted in the support rod  21 ′.  
     [0028] A rivet  24 ′ fastens the corresponding hollow joint  22 ′ and the corresponding support rod  21 ′ together.  
     [0029] Referring to FIG. 9, a third extensible leg frame  2 ″ comprises at least a support rod  21 ″, at least a tube  230 ″, at least a hollow joint  22 ″, and at least a bottom seat  23 ″.  
     [0030] The hollow joint  22 ″ is disposed on a top end of the support rod  21 ″.  
     [0031] The tube  230 ″ is disposed on the bottom seat  23 ″.  
     [0032] The support rod  21 ″ is inserted through the tube  230 ″.  
     [0033] A rivet  24 ″ fastens the corresponding hollow joint  22 ″ and the corresponding support rod  21 ″ together.  
     [0034] Referring to FIG. 10, a foldable chair seat  4  is disposed on the first extensible leg frame  2 .  
     [0035] The invention is not limited to the above embodiment but various modification thereof may be made. Further, various changes in form and detail may be made without departing from the scope of the invention.