Chair leg bridge connector and butterfly chair

Abstract

A chair leg bridge connector is shown. The bridge connector is made of stamp-molded steel plate. Two sets of curve sections face the same direction. The two bent surfaces of each set are parallel, and through hole is provided for rivet or axis to pass through. The through hole axial lines of the two sets of curve sections have a corner angle to allow bridge positioning of the two facade supporting frames. Butterfly chairs that use this type of bridge connector with reinforcement warp plate at the tube hinging spot can be directly formed using lighter tubes to make the structure more mobile.

I claim: 
     
         1 . A chair leg bridge connector, wherein the bridge connector is made of stamp-molded steel plate;
 two sets of curve sections face the same direction; and   the two bent surfaces of each set are parallel, and through hole is provided for rivet or axis to pass through.   
     
     
         2 . The chair of  claim 1 , wherein the hole axial lines corner angle of the two sets of curve sections are between 70 and 120 degrees. 
     
     
         3 . The chair of  claim 1 , wherein the bridge connector has a plastic cover on at least the floor-touching surface, and as the following two structures: 1) The plastic cover is independently formed and embedded on the bridge connector; and 2) The bridge connector is embedded and formed in the plastic cover. 
     
     
         4 . A butterfly chair that including a backrest fabric, side supporting frames with corresponding or symmetric facades on left and right sides, front supporting frame of the front facade and rear supporting frame of the rear facade, and chair leg bridge connector described by the aforementioned patent  claims 1  to  3 ;
 the aforementioned side supporting frames of the left and right facades and the front supporting frame and the rear supporting frame connect to form an overall structure that can be folded and opened; 
 the aforementioned backrest fabric is hung on the upper edge of the front and rear facades;
 its attributes are: Side supporting frames, front supporting frame and rear supporting frame are made of processed hollow tubes; 
 the floor-touching ends of the adjacent facade tubes cross-hinge on the holes of the corresponding curve sections of the aforementioned bridge connector; 
 at least in the front supporting frame, a reinforcement wrap plate is riveted or welded on the tube surface with a hinging point in the center; and 
 the reinforcement wrap plate covers the hinging section of the tube to share the weight bearing of the hinging axis or rivet. 
 
 
     
     
         5 . The chair of  claim 4 , wherein:
 the front supporting frame and rear supporting frame are both formed by two tubes that cross-hinge at the middle;
 the side supporting frames of the left and right facades include backrest bar, support bar, and seat bar; 
 the lower end of the aforementioned backrest bar cross-hinges to the bridge connector of the front floor-touching facade, and the upper part is cross-hinged to the upper end of the rear facade tube through the hinging part; 
 the lower end of the aforementioned supporting bar hinge to the bridge connector of the rear floor-touching facade, and the upper end is cross-hinged to the center of the backrest bar; 
 the seat bar hinges to the upper end of the front facade tube through the hinging part, and the rear end is hinged to the center of the backrest bar; and 
 At least two corners of the front end of the backrest fabric are fixed to the front end section of the two seat bars, and the rear end is fixed to the upper end section of the backrest bar. 
   
     
     
         6 . The chair of  claim 5 , wherein the side supporting frame, the seat bar and the supporting bar hinge to the backrest bar at the top and bottom, and hinge to the same side of the backrest bar;
 there is also a weight-bearing plate between the two hinge points; and   a reinforcement warp plate is riveted or welded the side surface of the aforementioned backrest bar that is farther away from the seat bar.   
     
     
         7 . The chair of  claim 6 , wherein the plastic pads are fixed to the front end section of the aforementioned seat bar and the upper end section of the backrest bar. 
     
     
         8 . The chair of  claim 4 , wherein:
 the hinge has a weight-bearing pad at the tube end section of the bridge connector;   the weight-bearing pad has a plastic round structure;   a rivet hole is formed at the center of the axis;   the radial side has a plug-in hole that aligns with the rivet hole;   the aforementioned tube is inserted into the aforementioned plug-in hole; and   the rivet for riveting the connector passes through the weight-bearing pad and tube to form a hinging structure for the three parts.   
     
     
         9 . The chair of  claim 4 , wherein the reinforcement wrap plate has a semi-circle curve;
 and the inner diameter and the outer diameter of the tube are similar and can adhere to the surface of the tube; and   the length of the reinforcement wrap plate is between 15 cm and 25 cm.   
     
     
         10 . The chair of  claim 5 , wherein:
 The two tubes cross-hinge at the center of the aforementioned front supporting frame and rear supporting frame;
 there is also a double-hinge chain between the two tubes above the rivet point; and 
 the double-hinge chain limits the opening angle of the front supporting frame and the rear supporting frame.