Tilt and swivel chair and mechanism therefor

A chair comprising:

• a seat;
• a base having legs that extend to the floor;
• an elongate structure connected to the seat at a first end, and to the base, and extending through the base to terminate at a second end, the base defining a longitudinal axis and comprising:
• a pillar assembly connected to the seat at the first end;
• an outer cover housing a portion of the pillar assembly;
• a tilt ring engaging in part a lower portion of the outer cover;
• a base portion connected to the tilt ring and the base;
• the base portion comprising a bearing assembly and a keyhole delimiter defining a keyhole;
• the pillar assembly and the outer cover being tiltable in any direction against the tilt ring to tilt the seat away from an axial orientation with respect to the longitudinal axis of the base when tilting force is applied from the seat, the tilt ring returning the pillar assembly and outer cover to the axial orientation when such tilting force is relieved;
• the pillar assembly, the outer cover, and the tilt ring being capable of swivelling at the bearing assembly to rotate the seat about the longitudinal axis;
• and
• a bottom end of the pillar assembly engaging the keyhole so as to limit the degrees of tilt permitted by the pillar assembly and the outer cover.

A chair comprising:

• a seat;
• a base having legs that extend to the floor;
• an elongate structure connected to the seat at a first end, and to the base, and extending through the base to terminate at a second end, the structure defining a longitudinal axis and comprising:
• a spring pillar assembly connected to the seat at the first end;
• an outer cover housing a portion of the pillar assembly;
• a tilt ring engaging in part a lower portion of the outer cover;
• a base portion connected to the tilt ring and the base;
• the base portion comprising a bearing assembly;
• the spring pillar assembly being movable between starting and ending positions along a second longitudinal axis defined by the spring pillar assembly and the outer cover of the structure to move the seat;
• the spring pillar assembly and the outer cover being tiltable in any direction against the tilt ring to tilt the seat away from an axial orientation with respect to the longitudinal axis when tilting force is applied from the seat, the tilt ring returning the spring pillar assembly and outer cover to the axial orientation when such tilting force is relieved;
• and
• the spring pillar assembly, the outer cover, and the tilt ring being capable of swivelling at the bearing assembly to rotate the seat about the longitudinal axis.