Chair back mechanism and control assembly

A chair assembly, comprising:

• a seat support structure;
• a back support structure movable between an upright position and a reclined position;
• a back tensioning assembly that biases the back assembly from the reclined position towards the upright position, wherein the back tension assembly is adjustable between a low tension position, wherein the back tensioning assembly applies a first biasing force to the back assembly, and a high tension position, wherein the back tensioning assembly applies a second biasing force to the back assembly, and wherein the second biasing force is substantially greater than the first biasing force;
• an actuator assembly operably coupled to the back tensioning assembly and adapted to adjust the back tensioning assembly between the low and high tension positions;
• a control input assembly operably coupled to the seat support structure, wherein at least a portion of the control input assembly may be actuated by a seated user by rotating the portion of the control input assembly;
• and
• a control link assembly operably coupling the control input assembly with the actuator assembly to adjust the back tensioning assembly between the low and high tension positions upon rotation of the portion of the control assembly by a seated user, wherein a number of rotations of the portion of the control input assembly is not limited by the control link.