Chair arm assembly

A chair assembly, comprising;

• a back support arrangement that includes a substantially rigid back frame member and a flexibly resilient forwardly-facing surface configured to support a user;
• a four-bar linkage assembly, comprising:
• a first linkage member having a first end and a second end;
• a second linkage member having a first end and a second end;
• a third linkage member having a first end pivotably coupled to the first end of the first linkage member for rotation about a first pivot point, and a second end pivotably coupled to the first end of the second linkage member for rotation about a second pivot point;
• and
• a fourth linkage member having a first end pivotably coupled to the second end of the first linkage member for rotation about a third pivot point, and a second end pivotably coupled to the second end of the second linkage member for rotation about a fourth pivot point;
• wherein the four-bar linkage assembly includes a lower end and an upper end that is adjustable between a raised position and a lowered position;
• and
• an arm rest assembly adapted to support the arm of a seated user thereon and supported on the upper end of the four-bar linkage assembly;
• wherein the lower end of the four-bar linkage assembly is pivotably supported from an arm support structure for pivotable movement about a fifth pivot point, such that the upper end of the four-bar linkage assembly is moveable between a first position and second position located laterally outward from the first position, and wherein the fifth pivot point is located forwardly of the back frame member.