Folding seat assembly for mounting to risers

Abstract

A seat includes a seat base including a seat base linkage, a backrest including a seat back linkage, a connector rod, and a frame. The seat base linkage is pivotally secured to the seat back linkage at a first pivot point. The seat base linkage is pivotally secured to the connector rod at a second pivot point. The connector rod is pivotally secured to the frame at a third pivot point. The seat back linkage is pivotally secured to the frame at a fourth pivot point. When the seat is adjusted between an opened position and a closed position, the first pivot point describes the arc of a circle.

1 . A seat, the seat comprising:
 a seat base including a seat base linkage;   a backrest including a seat back linkage;   a connector rod;   a frame;   wherein the seat base linkage is pivotally secured to the seat back linkage at a first pivot point;   wherein the seat base linkage is pivotally secured to the connector rod at a second pivot point;   wherein the connector rod is pivotally secured to the frame at a third pivot point;   wherein the seat back linkage is pivotally secured to the frame at a fourth pivot point; and   wherein, when the seat is adjusted between an opened position and a closed position, the first pivot point describes the arc of a circle.   
     
     
         2 . The seat of  claim 1 , further comprising a biasing member that biases the seat from the opened position toward the closed position. 
     
     
         3 . The seat of  claim 2 , wherein a biasing force applied by the biasing member automatically adjusts the seat from the opened position toward the closed position when the seat is unoccupied. 
     
     
         4 . The seat of  claim 2 , wherein the biasing member comprises a torsion spring. 
     
     
         5 . The seat of  claim 2 , wherein the biasing member is accommodated by the seat base linkage. 
     
     
         6 . The seat of  claim 1 , wherein the frame includes a first feature on a first side of the frame and a second feature on a second side of the frame opposite the first side of the frame, and wherein the first feature and the second feature provide an interlocking profile when the seat is stacked together with another seat. 
     
     
         7 . The seat of  claim 6 , wherein the first feature comprises a protrusion and the second feature comprises a notch, and wherein, when the seat is stacked together with the other seat, the protrusion of the seat engages with the notch of the other seat, precluding lateral movement of the seat and the other seat relative to one another. 
     
     
         8 . The seat of  claim 1 , wherein, with the seat in the closed position, the seat base linkage, the seat back linkage, and the connector rod are disposed between a first side of the frame and a second side of the frame opposite the first side of the frame. 
     
     
         9 . The seat of  claim 1 , wherein the seat back linkage comprises a locking mechanism, and wherein, when the seat is in the opened position, the locking mechanism engages the connector rod to preclude movement of the seat from the opened position. 
     
     
         10 . The seat of  claim 1 , wherein the frame comprises a first arm and a second arm that is spaced from the first arm, and wherein the seat base, the backrest, and the connector rod are disposed between the first arm and the second arm of the frame. 
     
     
         11 . The seat of  claim 10 , wherein, with the seat in the closed position, the seat base, the backrest, the connector rod, the first arm of the frame, and the second arm of the frame are axially parallel with one another. 
     
     
         12 . The seat of  claim 11 , wherein, with the seat in the opened position, (i) the seat base and the connector rod are axially parallel with one another and (ii) the seat base and the connector rod extend at a first angle relative to the first arm of the frame and the second arm of the frame. 
     
     
         13 . The seat of  claim 12 , wherein, with the seat in the opened position, the backrest extends at a second angle relative to the first arm of the frame and the second arm of the frame, and wherein the second angle is different from the first angle. 
     
     
         14 . The seat of  claim 12 , wherein the first angle comprises an acute angle. 
     
     
         15 . A seat, the seat comprising:
 a seat base including a seat base linkage;   a backrest including a seat back linkage;   a connector rod;   a frame comprising a first arm and a second arm that is spaced from the first arm;   wherein the seat base, the backrest, and the connector rod are disposed between the first arm and the second arm of the frame;   wherein a first pivot pin pivotally attaches the seat base linkage and the seat back linkage at a first pivot point;   wherein a second pivot pin pivotally attaches the seat base linkage and the connector rod at a second pivot point;   wherein a third pivot pin pivotally attaches the connector rod and the frame at a third pivot point;   wherein a fourth pivot pin pivotally attaches the seat back linkage and the frame at a fourth pivot point;   wherein, when the seat is moved from a closed position toward an opened position, (i) the seat base pivots relative to the seat back at the first pivot point in a first pivotal direction, (ii) the seat base pivots relative to the connector rod at the second pivot point in the first pivotal direction, (iii) the connector rod pivots relative to the frame at the third pivot point in a second pivotal direction that is opposite the first pivotal direction and (iv) the seat back pivots relative to the frame at the fourth pivot point in the second pivotal direction; and   wherein, with the seat in the opened position, the seat base extends at a first angle relative to the first arm of the frame and the second arm of the frame.   
     
     
         16 . The seat of  claim 15 , further comprising a biasing member that biases the seat from the opened position toward the closed position. 
     
     
         17 . The seat of  claim 16 , wherein the biasing member is accommodated by the seat base linkage. 
     
     
         18 . The seat of  claim 15 , wherein the frame includes a protrusion on a first side of the frame and a notch on a second side of the frame opposite the first side of the frame, and wherein the protrusion and the notch provide an interlocking profile when the seat is stacked together with another seat. 
     
     
         19 . The seat of  claim 15 , wherein the seat back linkage comprises a locking mechanism, and wherein, when the seat is in the opened position, the locking mechanism engages the connector rod to preclude movement of the seat from the opened position. 
     
     
         20 . The seat of  claim 15 , wherein, with the seat in the closed position, the seat base, the backrest, the connector rod, the first arm of the frame, and the second arm of the frame are axially parallel with one another. 
     
     
         21 . The seat of  claim 15 , wherein, with the seat in the opened position, (i) the seat base and the connector rod are axially parallel with one another and (ii) the seat base and the connector rod extend at the first angle relative to the first arm of the frame and the second arm of the frame. 
     
     
         22 . The seat of  claim 15 , wherein, with the seat in the opened position, the backrest extends at a second angle relative to the first arm of the frame and the second arm of the frame, and wherein the second angle is different from the first angle.