Abstract: A back construction for a seating unit includes a back frame, and a compliant back having a forwardly-protruding lumbar support section that is characteristically flexible and bendable, such that the compliant back can be flexed to a plurality of different convex shapes. Top and bottom connections pivotally connect the compliant back to the back frame. An adjustable force-generating mechanism is operably attached to at least one of the compliant back and the back frame. The force-generating mechanism is constructed to provide an adjustable biasing force that adjustably biases the lumbar support section forwardly for optimal lumbar support for a seated user's back, but the force-generating mechanism characteristically provides the biasing force without forcing a shape change in the compliant back. A vertically adjustable lumbar support is slidably attached to the back shell.

Abstract: A seating unit includes a flexible back including a concavely-shaped lumbar region, and a tensioned cover stretched over the concavely-shaped lumbar region. A lumbar device is fit between the front surface and the covering, with a tension of the covering biasing the lumbar device against the lumbar region and resulting in a frictional force retaining the lumbar device in a selected vertical position. In one form, the lumbar device is sufficiently stiff to maintain its vertical cross sectional shape and to change a shape of the lumbar region as the lumbar device is adjusted vertically, but is sufficiently flexible to conform to a horizontal shape of the lumbar region as a seated user moves and twists while seated in the seating unit.

Abstract: A seating unit is provided having a base assembly, a back frame pivoted to the base assembly for movement between upright and reclined positions, and a seat slidably supported on the base assembly and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. A flexible back is connected to the back frame at top and bottom locations and is provided with lumbar adjustment for improved lumbar force/support and shape. A seat is provided with seat depth adjustment and with active and passive thigh flex support. The seat includes a front section adjustably and/or flexibly supported on a rear section for optimal comfort while supporting a seated adult user's thighs, With the rear section being configured to carry a majority of the weight of a typical seated adult user. A novel energy mechanism is provided that includes a moment arm shift adjuster for adjusting the spring tension on the back frame.

Abstract: A back for a seating unit, such as a chair, includes a back frame and a compliant back that is flexibly bendable to define different curvilinear shapes for sympathetically and ergonomically supporting a seated user's back. The back includes a bracket with forwardly-extending flanges pivotally connecting the compliant back to the back frame at a bottom connection generally aligned with a seated user's hip joint. The back also includes a top connection pivotally connecting the back to the back frame above the first connection. An adjustable torsional force-generating mechanism is connected to the first connection that biases a lumbar portion of the compliant back forward with respect to the chair. The top and bottom connections, in combination with the adjustable force generating mechanism, constrain the compliant back to move over a range that provides excellent ergonomic lumbar support to a seated user.

Abstract: A seating unit is provided having a base assembly with a particularly shaped housing and rigid upright side arms, a back frame pivoted to the base assembly for movement between upright and reclined positions, and a seat slidably supported on the base assembly and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. A flexible back is connected to the back frame at top and bottom locations and is provided with lumbar adjustment for improved lumbar force/support and shape. A seat is provided with seat depth adjustment and with active and passive thigh flex support. A novel energy mechanism is provided that includes a moment arm shift adjuster for adjusting the spring tension on the back frame. The moment arm shift adjuster is readily adjustable and includes an overtorque device to prevent damage to components of the energy mechanism.

Abstract: A back for a seating unit, such as a chair, includes a back frame and a compliant back that is flexibly bendable to define different curvilinear shapes for sympathetically and ergonomically supporting a seated user's back. The back includes a belt bracket with forwardly-extending flanges pivotally connecting the back to the back frame at a first connection generally aligned with a seated user's hip joint. The back includes a second connection pivotally connecting the back to the back frame at a second location spaced vertically above the first connection. An adjustable force generating mechanism is connected to the first connection that biases a lumbar portion of the back forward with respect to the chair. The first and second connections, in combination with the adjustable force generating mechanism, constrain the compliant back to move over a range that provides excellent ergonomic lumbar support to a seated user.

Abstract: A seating unit is provided having a base assembly, a back frame pivoted to the base assembly for movement between upright and reclined positions, and a seat slidably supported on the base assembly and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. A flexible back is connected to the back frame at top and bottom locations and is provided with lumbar adjustment for improved lumbar force/support and shape. A seat is provided with seat depth adjustment and with active and passive thigh flex support. A novel energy mechanism is provided that includes a moment arm shift adjuster for adjusting the spring tension on the back frame. The moment arm shift adjuster is readily adjustable and includes an overtorque device to prevent damage to components of the energy mechanism.

Abstract: A back construction for a seating unit includes a back frame, and a compliant back having a forwardly-protruding lumbar support section that is characteristically flexible and bendable, such that the compliant back can be flexed to a plurality of different convex shapes. Top and bottom connections pivotally connect the compliant back to the back frame. An adjustable force-generating mechanism is operably attached to at least one of the compliant back and the back frame. The force-generating mechanism is constructed to provide an adjustable biasing force that adjustably biases the lumbar support section forwardly for optimal lumbar support for a seated user's back, but the force-generating mechanism characteristically provides the biasing force without forcing a shape change in the compliant back. A vertically adjustable lumbar support is slidably attached to the back shell.

Abstract: A back for a seating unit, such as a chair, includes a back frame and a compliant back that is flexibly bendable to define different curvilinear shapes for sympathetically and ergonomically supporting a seated user's back. The back includes a bracket with forwardly-extending flanges pivotally connecting the compliant back to the back frame at a bottom connection generally aligned with a seated user's hip joint. The back also includes a top connection pivotally connecting the back to the back frame above the first connection. An adjustable torsional force-generating mechanism is connected to the first connection that biases a lumbar portion of the compliant back forward with respect to the chair. The top and bottom connections, in combination with the adjustable force generating mechanism, constrain the compliant back to move over a range that provides excellent ergonomic lumbar support to a seated user.

Abstract: A seating unit is provided having a base assembly, a back frame pivoted to the base assembly for movement between upright and reclined positions, and a seat slidably supported on the base assembly and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. The pivots for connecting the back frame to the base assembly and for connecting the seat to the back frame permit quick fastenerless assembly by flexing the back frame during assembly. The pivots include rubber elements that permit flexing of a bearing element to prevent binding during rotation when the bearing element is not fully aligned with a pivot axis. A method of assembly including flexing the configured end sections of the back frame, positioning the configured ends adjacent opposite sides of the seat, and releasing the configured end sections so that they engage the seat, is also disclosed.

Abstract: An armrest construction for chairs includes an armrest support having a lower end constructed for attachment to a chair, an upper end, and a mounting block attached to the upper end. A pivot block is pivoted to the mounting block at a main pivot, the pivot block having an upwardly-extending follower. First and second gears are each pivoted to the pivot block, the gears having intermeshing teeth at an inner end such that rotation of the first gear causes the second gear to simultaneously rotate in an opposite direction, the first and second gears further having outer ends. A support plate having pivot/slide members engages the outer ends of the first and second gears, and further has a guide operably engaging the follower to guide lateral movement of the support plate along a predetermined path.

Abstract: A chair includes a base having a vertically extendable gas spring with an upwardly disposed release button movable horizontally/laterally between a vertically oriented locked position where the gas spring is lock and non-extendable, and a laterally shifted actuated position where the gas spring is released and extendable. A seat is mounted on the gas spring and includes an actuator constructed to selectively move the release button between the locked position and the actuated position with a sideways movement. The actuator includes a link slidably mounted to a control housing under the seat for horizontal movement, and a lever that is pivoted to a side of the control housing for operating the link. The link includes an aperture with angled side surfaces configured to facilitate downward assembly of the link onto the release button, but so that the side surfaces will actuate the release button when the link is moved laterally by the lever.

Abstract: A chair includes a back frame and a flexible back support operably supported on the back frame. The flexible back support includes a flexible lumbar region and a flanged bracket pivotally connected to the back frame at a back support pivot. A force adjusting device is attached to the back frame at the back support pivot for adjusting a torsional spring-generated biasing force on the flanged bracket relative to the back frame. The force adjusting device includes a housing, a base attached to the housing, a spring operably mounted in the housing, and a gear arrangement operably connected to a cup-shaped handle to biasingly adjust a position of the spring with mechanical advantage to adjust a tension of the spring. A clutch is operably attached between the gear arrangement and the handle.

Abstract: An armrest construction for chairs includes an armrest support having a lower end constructed for attachment to a chair, an upper end, and a mounting block attached to the upper end. A pivot block is pivoted to the mounting block at a main pivot, the pivot block having an upwardly-extending follower. First and second gears are each pivoted to the pivot block, the gears having intermeshing teeth at an inner end such that rotation of the first gear causes the second gear to simultaneously rotate in an opposite direction, the first and second gears further having outer ends. A support plate having pivot/slide members engages the outer ends of the first and second gears, and further has a guide operably engaging the follower to guide lateral movement of the support plate along a predetermined path.

Abstract: An armrest construction for chairs includes an armrest support having a lower end constructed for attachment to a chair, an upper end, and a mounting block attached to the upper end. A pivot block is pivoted to the mounting block at a main pivot, the pivot block having an upwardly-extending follower. First and second gears are each pivoted to the pivot block, the gears having intermeshing teeth at an inner end such that rotation of the first gear causes the second gear to simultaneously rotate in an opposite direction, the first and second gears further having outer ends. A support plate having pivot/slide members engages the outer ends of the first and second gears, and further has a guide operably engaging the follower to guide lateral movement of the support plate along a predetermined path.

Abstract: A chair control is provided for use with a chair having a base assembly including a base frame, a back frame pivoted to the base frame for movement between upright and reclined positions, and a seat slidably supported on the base frame and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. The chair control includes a novel energy mechanism comprising a control housing, a transverse spring positioned transversely in the housing, and a lever pivotally engaging a side of the housing to form a fulcrum with one end of the lever engaging the spring and another end of the lever engaging a synchronized seat and back arrangement. A moment arm shift adjuster is provided for adjusting the spring tension on the back frame. The moment arm shift adjuster is readily adjustable and includes an overtorque device to prevent damage to components of the energy mechanism.

Abstract: A chair is provided having a base assembly including a base frame, a back frame pivoted to the base frame for movement between upright and reclined positions, and a seat slidably supported on the base frame and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. A flexible back is connected to the back frame at top and bottom locations and is provided with lumbar adjustment for improved lumbar force/support and shape. A seat is provided with seat depth adjustment and with active and passive thigh flex support. A novel energy mechanism is provided that includes a transverse spring, a lever, and a moment arm shift adjuster for adjusting the spring tension on the back frame. The moment arm shift adjuster is readily adjustable and includes an overtorque device to prevent damage to components of the energy mechanism.

Abstract: A back construction for a chair includes a back shell having a plurality of horizontal bands defining a flexible lumbar section, with the back shell including non-parallel guides defined along its edges. A vertically adjustable lumbar support includes a panel body located at the flexible lumbar section, a bent wire member that engages the panel body and that is stretchable laterally, and opposing handles attached to ends of the bent wire member that engage the non-parallel guides. The opposing handles slidingly follow the guides and are movable between a first position where the bent wire member is flexed to a first width dimension, and a second position where the bent wire member is flexed to a second width dimension different than the first width dimension. Slots in the panel body retain the bent wire member to the panel body, but permit the bent wire member to be stretched horizontally during vertical adjustment of the lumbar support.

Abstract: A chair is provided having a base assembly with a particularly shaped housing and rigid upright side arms, a back frame pivoted to the base assembly for movement between upright and reclined positions, and a seat slidably supported on the base assembly and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. A flexible back is connected to the back frame at top and bottom locations and is provided with lumbar adjustment for improved lumbar force/support and shape. A seat is provided with seat depth adjustment and with active and passive thigh flex support. A novel energy mechanism is provided that includes a moment arm shift adjuster for adjusting the spring tension on the back frame. The moment arm shift adjuster is readily adjustable and includes an overtorque device to prevent damage to components of the energy mechanism.

Abstract: A chair is provided having a base assembly, a back assembly pivoted to the base assembly for movement between upright and reclined positions, and a seat slidably supported on the base assembly and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. A flexible back is connected to the back frame at top and bottom locations and is provided with lumbar adjustment for improved lumbar force/support and shape. A seat is provided with seat depth adjustment and with active and passive thigh flex support. A novel energy mechanism is provided that includes a moment arm shift adjuster for adjusting the spring tension on the back frame. The moment arm shift adjuster is readily adjustable and includes an overtorque device to prevent damage to components of the energy mechanism.