Footrest mechanism, chair support structure and chair having same

Abstract

The present disclosure provides a footrest mechanism, a chair support structure and a chair. The footrest mechanism comprises a first support component, a first folding arm, a first rotating member and a first leg connecting rod, which can define a first four-bar mechanism. The first leg connecting rod is connected to the chair component, and is pivotally connected to the first rotating member. The first folding arm is pivotally connected to the first rotating member and the first support component, respectively. The first support component is pivotally connected to the first leg connecting rod. The first leg connecting rod is capable of moving towards or away from the chair component, and rotating relative to the first rotating member. The first leg connecting rod has a first state and a second state.

We claim: 
     
         1 . A footrest mechanism, comprising a first support component, a first folding arm, a first rotating member and a first leg connecting rod; wherein the first leg connecting rod is connected to the chair component, and is pivotally connected to the first rotating member; the first folding arm is pivotally connected to the first rotating member and the first support component, respectively; and the first support component is pivotally connected to the first leg connecting rod; a first leg four-bar mechanism is defined by the first support component, the first folding arm, the first rotating member and the first leg connecting rod four-bar;
 the first leg connecting rod is capable of moving towards or away from the chair component, and rotating relative to the first rotating member, so as to drive the first leg four-bar mechanism to contract or expand; 
 the first leg four-bar mechanism has a first state and a second state; 
 when the first leg four-bar mechanism is in the first state, the first folding arm is close to the first rotating member, the first leg connecting rod is configured for driving the first support component to move close to the first rotating member, and the first leg four-bar mechanism is folded; and 
 when the first leg four-bar mechanism is in the second state, the first folding arm is away from the first rotating member, and the first leg connecting rod is configured for driving the first support component to move away from the first rotating member, and the first leg four-bar mechanism is expanded. 
 
     
     
         2 . The footrest mechanism of  claim 1 , wherein the first leg four-bar mechanism is in a concave quadrilateral shape when the first leg four-bar mechanism is in the second state. 
     
     
         3 . The footrest mechanism of  claim 1 , wherein the first leg four-bar mechanism comprises a first limiting element; and when the first leg four-bar mechanism is in the first state, the first limiting element is configured for limiting at least one of the first rotating member, the first folding arm, the first support component and the first leg connecting rod, and limiting a folding range of the first leg four-bar mechanism. 
     
     
         4 . The footrest mechanism of  claim 3 , wherein the first limiting element is fixed to the first rotating member; and when the first leg four-bar mechanism is in the first state, the first limiting element is configured for limiting the first leg connecting rod. 
     
     
         5 . The footrest mechanism of  claim 1 , wherein the first leg four-bar mechanism comprises a second limiting element; when the first leg four-bar mechanism is in the second state, the second limiting element is configured for limiting at least one of the first rotating member, the first folding arm, the first support component and the first leg connecting rod, and limiting an expanding range of the first leg four-bar mechanism. 
     
     
         6 . The footrest mechanism of  claim 5 , wherein the second limiting element is fixed to the first rotating member; and when the first leg four-bar mechanism is in the second state, the second limiting element is configured for limiting the first support component. 
     
     
         7 . A chair support structure, comprising a movable chair mechanism and a footrest mechanism of  claim 1 , wherein the movable chair mechanism comprises a chair component, and the footrest mechanism is connected to the chair component. 
     
     
         8 . The chair support structure of  claim 7 , wherein the movable chair mechanism further comprises an intermediate transmission component and an installation component, wherein the intermediate transmission component comprises a first transmission connecting rod, a second transmission connecting rod and a third transmission connecting rod;
 the first transmission connecting rod and the third transmission connecting rod are pivotally connected to the chair component, respectively; and two ends of the second transmission connecting rod are pivotally connected to the first transmission connecting rod and the third transmission connecting rod, respectively;   the installation component comprises a fixing rod, a first swing arm and a second swing arm; wherein the fixing rod is fixed to a base, two ends of the first swing arm are pivotally connected to the first transmission connecting rod and the fixing rod, respectively; two ends of the second swing arm are pivotally connected to the third transmission connecting rod and the fixing rod, respectively; and   the installation component is capable of expanding or contracting to drive the intermediate transmission component to move, and the intermediate transmission component is capable of driving the chair component to move along a first direction.   
     
     
         9 . The chair support structure of  claim 7 , wherein the chair support structure comprises two sets of the footrest mechanism and two sets of the movable chair mechanism, and the two sets of the footrest mechanism and the two sets of the movable chair mechanism are capable of moving synchronously and correlatively, respectively. 
     
     
         10 . A chair, comprising the base and the chair support structure of  claim 7 , wherein the movable chair mechanism is connected to the base. 
     
     
         11 . The chair of  claim 10 , wherein the chair further comprises a driving component, the driving component is pivotally connected to the footrest mechanism and the chair component, respectively; and
 the driving component is capable of driving the footrest mechanism to move towards or away from the chair component, and driving the chair component to move along the first direction.