Height-adjustable chair back

A chair comprising:

• a seat assembly mounted on a base:
• a vertically elongate upright which is connected to a rear section of said seat assembly, said upright including a plurality of vertically spaced openings;
• a back assembly;
• and
• a height-adjustment assembly which is connected to said back assembly and includes a housing, a spring plate and an actuator;
• said housing defining a downward opening slot which receives an upper end of said upright therein, said housing having a side wall defining one side of said slot;
• said spring plate including a plate-like mounting section facing towards said side wall which has at least one mounting part formed integral therewith, said mounting part projecting rearwardly into engagement with said side wall of said housing to mount said spring plate thereon, said spring plate including an elongate resilient leg formed integral with said mounting section, said resilient leg including a catch formed integrally therewith which projects through said side wall into said slot, said catch being biased into engagement with a selected one of said apertures in said upright to prevent downward movement of said back assembly, said projection being movable out of engagement with said apertures in response to upward movement of said back assembly so as to be slidable upwardly along said upright;
• and
• said actuator having a movable end section engaged with said spring leg such that said spring leg resists movement of said actuator, said actuator being movable to deflect said spring leg outwardly and move said catch out of engagement with said apertures to permit downward movement of said back assembly.

A height-adjustment assembly for slidably supporting a back assembly to a seat assembly of a chair comprising:

• a housing which defines a downward opening slot therein, a front wall defining a front side of said slot, and bearing parts disposed on said front wall;
• a spring plate which includes a plate-like mounting section having at least one mounting part formed integral therewith, said mounting part projecting rearwardly into engagement with said front wall of said housing to mount said spring plate on said housing, said spring plate including an elongate resilient leg formed integral with said mounting part which includes a catch thereon, said catch projecting through said front wall into said slot;
• and
• an actuator lever having pivot means for pivotally engaging said actuator lever to said bearing parts so as to be pivotable about a pivot axis, said actuator lever including an end section connected to said spring leg such that said spring leg resists pivoting of said actuator lever, said actuator lever deflecting said spring leg during pivoting thereof to move said projection out of said slot.