An ergonomically improved chair in which the user's thoracic region is supported by a narrow and generally flat or moderately convex thoracic cushion in the midrest region of the chairback. The design omits or greatly minimizes support for the user's scapulae and other areas of the back outside the thoracic region, excepting lumbar and cervical support features in some embodiments. The design differs from the prior art at least in that the thoracic cushion is narrow and configured not to complement that user's spinal curvature. By appropriate selection and design, a chair incorporating the invention may comprise a fabric covering portions of the chairback without significantly affecting functionality. Other embodiments include a chairback comprising regions having differing levels of firmness and/or differing cushion height at appropriate regions to promote concentrated support of the user's thoracic region.

A chair back height adjustment mechanism comprises a guide having an abutment surface at a lateral side of the guide which extends along an adjustment direction. The chair back height adjustment mechanism comprises an adjusting device supported on the guide so as to be displaceable along the adjustment direction. The adjusting device comprises a carrier, a coupling member which is moveably supported on the carrier, and a bias mechanism. The coupling member has a contact face shaped to abut on the abutment surface of the guide and a slanted face. The bias mechanism is operative to apply a force onto the slanted face to urge the contact face of the coupling member against the abutment surface of the guide.

A lift adjuster is depicted and described for adjusting seating furniture and/or reclining furniture, with a housing and an adjustment bracket. The adjustment bracket is maintained in the housing and can be partially pulled out of the housing. In order to enable comfortable adjustment, it is proposed that at least one clamping element is provided displaceable with respect to the adjustment bracket between a clamping position and at least one adjustment position in that the at least one clamping element is received in a clamping manner in the clamping position in a clamping gap between the adjustment bracket and the housing such that the adjustment bracket is prevented from sliding into the housing.

The element with variable shape (1) is composed of a cushion (10), having inside a fixed frame (20), which involves a lower section (13) of said cushion (10) and two symmetrical movable frames (25A), (25B), hinged above said fixed frame (20) and aimed at involving an upper section (14) of the cushion (10). The movable frames (25A), (25B) can rotate by 180° independently from each other, to direct a respective portion (14A), (14B) of said upper section (14) from an external horizontal configuration (HE) to an inner horizontal configuration (HI), passing through a vertical neutral configuration (N), in which the portion (14A), (14B) is substantially aligned with said lower section (13). The back (100) and sides (110) of a sofa (D) or armchair (P) are defined by respective elements (1), which can be configured in many ways so as to offer the maximum sitting comfort.

A sleeve for installing hinge is provided, a mounting hole is opened in a top plate, wherein the sleeve for installing hinge comprises a main body capable of inserting into the mounting hole and a stopper fixed to an upper end of the main body and withstood with a top surface of the top plate, a slot where a hinge is inserted therein is opened in the sleeve for installing hinge, the slot passes through the stopper and extends down into the main body, a hook is configured at a side wall of the main body, the hook is deformed under pressure so as to allow the main body and the hook to pass through the mounting hole, the hook has a stop surface facing up, after the main body and the hook pass through the mounting hole, the stop surface faces a bottom surface of the top plate.

A height adjusting mechanism for a dentistry stool comprises a support member, a movable height adjusting assembly and a pushbutton actuator. The support member is coupleable to the stool adjacent a seat of the stool. The movable height adjusting assembly is selectively movable up and down relative to the support member. The pushbutton actuator is positionable on a side of the movable height adjusting assembly adjacent a seated user, and is manually actuatable by the seated user to release the movable height adjusting assembly from a locked position at a current height to allow the movable height adjusting assembly to be moved to a new height. The height adjusting mechanism can be implemented to provide a height-adjustable seat back and/or a height-adjustable torso bar.

A seat back support assembly comprises a vehicle engaging member and a seat back receiving member. The vehicle engaging member is configured to be secured to a vehicle body. The vehicle engaging member includes a supporting section. The seat back receiving member includes (i) a base that is adjustably coupled to the supporting section, and (ii) a receiver that is coupled to the base, the receiver being configured to receive the seat back. The base is alternately positioned in a first vertical position and a second vertical position relative to the supporting section. When the base is in the first vertical position, the seat back is at a first height relative to the vehicle seat. Alternatively, when the base is in the second vertical position, the seat back is at a second height relative to the vehicle seat that is different than the first height.

A portable lumbar support and ergonomic chair having a lumbar support. The lumbar support has a seat hingedly coupled to a seat back having a teardrop-shaped lumbar support seat back cushion. A rigid back support portion may be rotated forward about hinges to collapse substantially parallel to the seat frame and backward to open to a variety of angles with respect to the seat frame. The seat back freely pivots around an upper lateral axis, and the rigid back support portion is linearly adjustable to space the seat back toward and away from the hinges to enable raising or lowering the upper lateral axis and thus the seat back with respect to the lower lateral axis. This provides multiple ways of changing which part of the teardrop-shaped lumbar support curve hits your lumbar curve for proper support. Variable lumbar lordotic support is thus provided.

An ergonomically improved chair in which the user's thoracic region is supported by a narrow and generally flat or moderately convex thoracic cushion in the midrest region of the chairback. The design omits or greatly minimizes support for the user's scapulae and other areas of the back outside the thoracic region, excepting lumbar and cervical support features in some embodiments. The design differs from the prior art at least in that the thoracic cushion is narrow and configured not to complement that user's spinal curvature. By appropriate selection and design, a chair incorporating the invention may comprise a fabric covering portions of the chairback without significantly affecting functionality. Other embodiments include a chairback comprising regions having differing levels of firmness and/or differing cushion height at appropriate regions to promote concentrated support of the user's thoracic region.

A chair is described herein. The chair includes a first back support coupled to a base of the chair using one or more first support arms. The chair also includes a second back support coupled to the base of the chair using one or more second support arms. The first and second back supports are independently rotatable about a common axis.