Chair arm assembly

A chair assembly, comprising:

• an arm support structure;
• an arm rest assembly adapted to support the arm of a seated user thereon;
• an arm support assembly having a lower end supported by the arm support structure, and an upper end supporting the arm rest assembly thereon, wherein the arm support assembly is adjustable between a vertically raised position and a vertically lowered position;
• and
• a locking assembly, comprising:
• a first locking link having at least one of a first surface and a plurality of teeth;
• a second locking link having the other of the first surface and the plurality of the teeth, and movable between a locked position, wherein the first surface engages at least one of the plurality of teeth to prevent adjustment of the arm support assembly between the raised and lowered positions, and an unlocked position, wherein the first surface is spaced from the plurality of teeth, thereby allowing the arm support assembly to be adjusted between the raised and lowered positions;
• an actuator link operably coupled with the first locking link and adapted to move between a first position, wherein the first locking link is moved by the actuator link to the locked position, and a second position, wherein the first locking link is moved by the actuator link to the unlocked position;
• and
• an actuator member operably coupled with the actuator link, wherein at least a portion of the actuator member may be actuated by a seated user, thereby allowing the user to move the actuator link between the first and second positions;
• and
• wherein the second locking link is biased towards the locked position by a leaf spring.

A chair assembly, comprising:

• an arm support structure;
• an arm rest assembly adapted to support the arm of a seated user thereon;
• an arm support assembly having a lower end supported by the arm support structure, and an upper end supporting the arm rest assembly thereon, wherein the arm support assembly is adjustable between a vertically raised position and a vertically lowered position;
• and
• a locking assembly, comprising:
• a first locking link having at least one of a first surface and a plurality of teeth;
• a second locking link having the other of the first surface and the plurality of the teeth, and movable between a locked position, wherein the first surface engages at least one of the plurality of teeth to prevent adjustment of the arm support assembly between the raised and lowered positions, and an unlocked position, wherein the first surface is spaced from the plurality of teeth, thereby allowing the arm support assembly to be adjusted between the raised and lowered positions;
• an actuator link operably coupled with the first locking link and adapted to move between a first position, wherein the first locking link is moved by the actuator link to the locked position, and a second position, wherein the first locking link is moved by thee actuator link to the unlocked position;
• and
• an actuator member operably coupled with the actuator link, wherein at least a portion of the actuator member may be actuated by a seated user, thereby allowing the user to move the actuator link between the first and second positions;
• and
• wherein the actuator link includes a leaf spring.

A chair assembly, comprising:

• an arm support structure;
• an arm rest assembly adapted to support the arm of a seated user thereon;
• an arm support assembly having a lower end supported by the arm support structure, and an upper end supporting the arm rest assembly thereon, wherein the arm support assembly is adjustable between a vertically raised position and a vertically lowered position;
• and
• a locking assembly, comprising:
• a first locking link having at least one of a first surface and a plurality of teeth;
• a second locking link having the other of the first surface and the plurality of the teeth, and movable between a locked position, wherein the first surface engages at least one of the purality of teeth to prevent adjustment of the arm support assembly between the raised and lowered positions, and an unlocked position, wherein the first surface is spaced from the plurality of teeth, thereby allowing the arm support assembly to be adjusted between the raised and lowered positions;
• an actuator link operably coupled with the first locking link and adapted to move between a first position, wherein the first locking link is moved by the actuator link to the locked position, and a second position, wherein the first locking link is moved by the actuator link to the unlocked position;
• and
• an actuator member operably coupled with the actuator link, wherein at least a portion of the actuator member may be actuated by a seated user, thereby allowing the user to move the actuator link between the first and second positions;
• and
• wherein the actuator link includes an arcuately-shaped abutment surface, and
• wherein the actuator member abuts the abutment surface of the actuator link.

An arm rest assembly for an office chair, the armrest assembly comprising:

• an outer member having a cushion mounted thereto;
• an inner member configured to be secured to an office chair structure, the inner member having teeth disposed thereon;
• upper and lower members extending between and pivotably coupling the inner and outer members to form a four-bar linkage;
• a vertical adjustment lock assembly to lock the height of the cushion relative to the inner member;
• the vertical adjustment lock assembly comprising:
• a movable release member;
• an actuator member that shifts between a locked position and an unlocked position upon movement of the release member, the actuator member defining a base end;
• a pivotable locking member with teeth that selectively engage the teeth on the inner member of the four-bar linkage;
• and
• a spring biasing the actuator member towards the locked position and also biasing the teeth of the pivotable locking member out of engagement with the teeth on the inner member of the four-bar linkage;
• wherein the base end of the actuator member moves into a first recess of the locking member to permit movement of the locking member teeth out of engagement with the teeth of the inner member of the four-bar linkage;
• and
• a second lock including a locking second recess in the locking member that receives the end of the actuator member and prevents movement of the locking member when a downward force is applied to the cushion.

A chair assembly, comprising:

• a base structure defining an upper portion and a lower portion located below the upper portion;
• a seat support structure including an upwardly-facing seat support surface configured to support a seated user thereon;
• an upwardly-extending back structure having a forwardly-facing back support surface configured to support a user's back in a generally upright position;
• a control link having a first end pivotably coupled to the rearward portion of the seat support structure, and a second end pivotably coupled to the rearward portion of the back support structure;
• an arm rest assembly including an arm support structure coupled to the seat support structure, the arm rest assembly having an upwardly-facing arm support surface that is movable upwardly and downwardly, and a four-bar linkage assembly movably coupled to the arm support structure and the arm rest assembly, wherein the four-bar linkage assembly comprises:
• 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 first, second, third, and fourth pivot points define first, second, third, and fourth corners of the four-bar linkage, respectively, and wherein the first and fourth corners define a diagonal distance therebetween that becomes smaller as the arm support surface moves downwardly;
• and
• a rigid link operably coupling the first and fourth corners to thereby place the rigid link in compression to prevent the diagonal distance from becoming smaller to thereby lock the arm support surface at a user-selected height.