Chair construction

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• a flexible polymeric sheet attached at upper and lower connections to the back upright;
• and
• a vertically adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region, wherein the lower connection is resilient and includes a tensioner.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• a flexible polymeric sheet attached at upper and lower connections to the back upright;
• and
• a vertically adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region, wherein the vertically adjustable lumbar mechanism is also horizontally adjustable.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• a flexible polymeric sheet attached at upper and lower connections to the back upright;
• and
• a vertically adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region, wherein the sheet includes perforations, and wherein the perforations include slots;
• wherein the sheet includes slots that are oriented and arranged to provide non-uniform flexibility across the sheet.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• a flexible polymeric sheet made from a solid sheet of non-textile material attached at upper and lower connections to the back upright;
• and
• a vertically adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region wherein the sheet Is one of translucent or transparent.

A seating unit comprising:

• a base;
• a back upright pivotally supported on the base for movement between an upright position and a reclined position;
• a flexible sheet made from a solid sheet of non-textile material operably supported on the back upright and adapted to ergonomically support a seated user;
• and
• a vertically adjustable lumbar mechanism operably movably attached to the back upright and configured to bend the flexible sheet and change a shape of the flexible sheet forwardly to ergonomically adjustably support a lumbar region of the seated user.

A seating unit comprising:

• base;
• a back upright pivotally supported on the base for movement between an upright position and a reclined position;
• a flexible sheet operably supported on the back upright and adapted to ergonomically support a seated user;
• and
• a vertically adjustable lumbar mechanism operably movably attached to the back upright and configured to bend the flexible sheet and change a shape of the flexible sheet forwardly to ergonomically adjustably support a lumbar region of the seated user;
• and
• an upper connection pivotally connecting the flexible sheet to the back upright.

A seating unit comprising:

• a base;
• a back upright pivotally supported on the base for movement between an upright position and a reclined position;
• a flexible sheet operably supported on the back upright and adapted to ergonomically support a seated user;
• and
• a vertically adjustable lumbar mechanism operably movably attached to the back upright and configured to bend the flexible sheet and change a shape of the flexible sheet forwardly to ergonomically adjustably support a lumbar region of the seated user, wherein the vertically adjustable lumbar mechanism is also horizontally adjustable.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• a flexible polymeric sheet made from a solid sheet of non-textile material attached at upper and lower connections to the back upright, the lower connection being near a bottom of the sheet;
• the sheet including perforations, at least some of which are slots, allowing airflow, the sheet including a support surface adapted to ergonomically engage and support a seated user;
• and
• a vertically adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• a flexible polymeric sheet attached at upper and lower connections to the back upright, the lower connection being near a bottom of the sheet:
• the sheet including perforations, at least some of which are slots, allowing airflow, the sheet including a support surface adapted to ergonomically engage and support a seated user;
• and
• a vertically adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region, wherein the slots are oriented to cause a region of flexibility in the sheet.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• a flexible polymeric sheet attached at upper and lower connections to the back upright, the lower connection being near a bottom of the sheet;
• the sheet including perforations, at least some of which are slots, allowing airflow, the sheet including a support surface adapted to ergonomically engage and support a seated user;
• and
• a vertically adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region, wherein at least a portion of the sheet is translucent.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• a flexible polymeric sheet attached at upper and lower connections to the back upright, the lower connection being near a bottom of the sheet;
• the sheet including perforations, at least some of which are slots, allowing airflow, the sheet including a support surface adapted to ergonomically engage and support a seated user;
• and
• a vertically adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region, wherein the adjustable lumbar mechanism is also horizontally adjustable.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• the seat being operably supported to move synchronously during recline of the back upright;
• a flexible polymeric sheet made from a solid sheet of non-textile material attached at upper and lower connections to the back upright, the lower connection being near a bottom of the sheet;
• the sheet including perforations allowing airflow and including a support surface adapted to ergonomically engage and support a seated user;
• and
• an adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions;
• the seat being operably supported to move synchronously during recline of the back upright;
• a flexible polymeric sheet attached at upper and lower connections to the back upright, the lower connection being near a bottom of the sheet;
• the sheet including perforations allowing airflow and including a support surface adapted to ergonomically engage and support a seated user;
• and
• an adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region, wherein the sheet is translucent.

A chair comprising:

• a base,
• a chair control mounted on the base;
• a seat supported on the chair control;
• a back upright pivotally attached to the chair control for movement between upright and reclined positions, the back upright including a vertically-elongated centrally-located spine component extending along a symmetrical vertical centerline of the chair control;
• a flexible polymeric sheet attached at upper and lower connections to the back upright;
• and
• a vertically adjustable lumbar mechanism attached to the back upright and configured to bend the flexible sheet forwardly between the upper and lower connections to support a seated user's lumbar region.