Folding chair for safety use

Abstract

A folding chair for safety use includes a seat plate and two support frames. Each of the two support frames comprises a front leg and a rear leg, and the rear leg comprises a rear leg tube and a moving tube movably disposed in the rear leg tube. The moving tube is pivotally connected to the front leg. The rear leg is configured to be extended to cause the folding chair to be in a folded state, and the rear leg is configured to be contracted to cause the folding chair to be in an unfolded state. At least one of the two support frames comprises a locking member. When in a locked position, the locking member is configured to prevent the moving tube from moving in the rear leg, and the locking member is configured to be released to enable the moving tube to freely move.

What is claimed is: 
     
         1 . A folding chair for safety use, comprising:
 a seat plate, and   two support frames symmetrically disposed on a left side and a right side of the seat plate, wherein:
 each of the two support frames comprises a front leg and a rear leg, 
 the rear leg comprises a rear leg tube and a moving tube movably disposed in the rear leg tube, 
 the rear leg tube and the front leg are respectively pivotally connected to the seat plate, 
 the moving tube is pivotally connected to the front leg, 
 the rear leg is configured to be extended to cause the folding chair to be in a folded state, 
 the rear leg is configured to be contracted to cause the folding chair to be in an unfolded state, 
 at least one of the two support frames comprises a locking member, 
 the locking member is movably disposed on the rear leg tube so that the locking member is detachably connected to the moving tube in a locked position, or the locking member is movably disposed on the front leg or a joint between the front leg and the moving tube so that the locking member is detachably connected to the rear leg tube in the locked position, and 
 when in the locked position:
 the locking member is configured to prevent the moving tube from moving in the rear leg, and 
 the locking member is configured to be released to enable the moving tube to freely move. 
 
   
     
     
         2 . The folding chair according to  claim 1 , further comprising:
 a rotating arm, wherein:
 a first end of the rotating arm is pivotally connected to the moving tube, the front leg, or the joint between the front leg and the moving tube, 
 a second end of the rotating arm is a free end which defines the locking member, 
 the locking member is a buckle sub-piece, 
 a wall of the rear leg tube comprises a buckle piece configured to be buckled to the buckle sub-piece, and 
 when the rear leg is contracted:
 the buckle sub-piece is locked to the buckle piece in the locked position, and the folding chair is locked in the unfolded state. 
 
   
     
     
         3 . The folding chair according to  claim 2 , wherein:
 a third end of the rotating arm away from the buckle sub-piece extends to define a handle,   the folding chair comprises an elastic member,   the elastic member is a torsion spring,   a spring body of the torsion spring is sleeved on the first end of the rotating arm,   a first torsion arm of the torsion spring is fixedly disposed on the moving tube, the front leg, or the joint between the front leg and the moving tube,   a second torsion arm of the torsion spring abuts the buckle sub-piece, and   when the folding chair is in the folded state, the torsion spring is in a free state.   
     
     
         4 . The folding chair according to  claim 3 , wherein:
 the front leg is pivotally connected to the moving tube through a hinge, and   the rotating arm is pivotally connected to the joint between the front leg and the moving tube.   
     
     
         5 . The folding chair according to  claim 1 , wherein:
 the locking member is a locking pin,   the rear leg tube comprises a first locking hole,   the moving tube comprises a second locking hole,   the locking pin is movably disposed in an axial direction of the first locking hole, and   when the rear leg is contracted:
 the first locking hole and the second locking hole correspond to each other, 
 the locking pin is locked to the first locking hole and the second locking hole at the same time in the locked position, and 
 the folding chair is locked in the unfolded state. 
   
     
     
         6 . The folding chair according to  claim 5 , wherein:
 a bottom end of the moving tube comprises a guiding slope inclining gradually away from a central axis of the moving tube from bottom to top.   
     
     
         7 . The folding chair according to  claim 5 , further comprising:
 a rotating arm, and   an elastic member, wherein:
 a first end of the rotating arm is pivotally connected to the rear leg tube, 
 a second end of the rotating arm is a free end pivotally connected to the locking pin, 
 two opposite ends of the elastic member respectively abuts the rotating arm and the rear leg tube, and 
 when the locking pin is in the locked position, the elastic member is in a free state. 
   
     
     
         8 . The folding chair according to  claim 7 , wherein:
 a third end of the rotating arm away from the locking pin extends to define a handle,   the elastic member abuts the handle and the rear leg tube, and   the elastic member is a compression spring.   
     
     
         9 . The folding chair according to  claim 8 , wherein:
 the rotating arm is pivotally connected to the rear leg tube,   an outer wall of the rear leg tube is disposed with a handle position-limiting groove configured to correspond to the handle,   the locking member is a buckle sub-piece, and   when the handle is buckled to the handle position-limiting groove, the buckle sub-piece is at a farthest position from the rear leg tube or the moving tube.   
     
     
         10 . The folding chair according to  claim 1 , wherein:
 the rear leg tube further comprises a fixed rivet fixedly inserted into a wall of the rear leg tube,   a length of the fixed rivet entering the rear leg tube is greater than a distance between an inner wall of the rear leg tube and an outer wall of the moving tube, and   when the folding chair is in the unfolded state, a bottom end of the moving tube abuts the fixed rivet.   
     
     
         11 . The folding chair according to  claim 6 , further comprising:
 a rotating arm, and   an elastic member, wherein:
 a first end of the rotating arm is pivotally connected to the rear leg tube, 
 a second end of the rotating arm is a free end pivotally connected to the locking pin, 
 two opposite ends of the elastic member respectively abuts the rotating arm and the rear leg tube, and 
 when the locking pin is in the locked position, the elastic member is in a free state. 
   
     
     
         12 . The folding chair according to  claim 11 , wherein:
 a third end of the rotating arm away from the locking pin extends to define a handle,   the elastic member abuts the handle and the rear leg tube, and   the elastic member is a compression spring.   
     
     
         13 . The folding chair according to  claim 12 , wherein:
 the rotating arm is pivotally connected to the rear leg tube,   an outer wall of the rear leg tube is disposed with a handle position-limiting groove configured to correspond to the handle,   the locking member is a buckle sub-piece, and   when the handle is buckled to the handle position-limiting groove, the buckle sub-piece is at a farthest position from the rear leg tube or the moving tube.