A lower chair for supporting an upper chair on which a user sits. The lower chair including a base, a swivel mechanism supported by the base and defining a vertical swivel axis, and a four-bar linkage mounted to the swivel mechanism for rotation about the swivel axis. The four-bar linkage includes a coupler link that moves about a coupler curve. The lower chair also includes a column having a lower end affixed to the coupler link for movement of the lower end along the coupler curve. The column defines a column axis and is adapted to support the upper chair.

A chair for reducing a load on the buttocks and the waist, and, to a chair (100) includes a seat (110) and a backrest (130) and further comprising a spacer (120) protruding upward from the rear end of the seat (110), wherein the bottom of the backrest (130) is provided on the top of the spacer (120) so as to be tiltable rearward, and the point at which the angle of the backrest (130) is adjusted with respect to the spacer (120) corresponds to a point (P) at which the lumbar of a user body sitting on the seat (110) is curved inward.

An ergonomic chair (300) comprising a seat (310), a lower leg support (320), a chest support (330), and a hip support (360); the seat (310) for supporting the posterior thigh (11) and/or buttocks (12) of a seated user (10), the seat (310) being configured to urge the hip of a seated user (10) in a forward direction; the lower leg support (320) for supporting the anterior side of the lower legs (14) of the seated user (10); the chest support (330) for supporting the chest (15) of the seated user (10) in a forward leaning position of the seated user (10); the hip support (360) is configured to support the anterior hip of a seated user (10) as the seat (310) urges the seated user's (10) hip forwardly towards the hip support (360).

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.

An apparatus that supports a user in a variety of positions to comfortably perform tasks, such as applying one or more tattoos to skin of a subject is herein disclosed. The apparatus can be reconfigured to optimally position and support the arms and/or chest of the user. The apparatus includes a vertically movable armrest assembly. Armrests can support the user's forearms while supporting the user's chest such that the user can comfortably perform tasks in front of a chest support of the stool. The armrest assembly can be translated vertically to accommodate the user's body to achieve desired positioning.

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 inclues 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.

A back adjustment system for a chair having a frame that includes a top end and bottom end. The back adjustment system may further include a chair back having a first end and a second end. The first end of the chair back may be mounted solely to the top end of the frame of the chair and also includes an adjusting means, which may be mounted at the bottom end of the frame. The adjusting means may allow for engagement between the bottom end of the frame and the second end of the chair back. The adjusting means may be adapted to telescopically engage between the bottom end of the frame and the second end of the chair back thereby solely moving the second end of the chair back from a retracted position to an extended position.

The invention relates to a chair, having a chair base (1), a seat part (5, 6, 7, 8) connected thereto, a backrest (9, 16, 17) connected thereto, the seat part (5, 6, 7, 8) pivotable about at least one horizontal or inclined horizontal axis and the backrest (9, 16, 17) are spatially adjustable. The seat part (5, 6, 7, 8) has at least three seat elements (5, 6, 7) that can be adjusted in relation to one another and whose operating positions can be adjusted individually.

The invention relates generally to a lightweight, collapsible, and portable wheeled seat, e.g., a wheeled office chair or stool, for travel, storage, and mobility. The seat includes a seat base member and a seat surface member collapsible between an open, extended position, which is configured to provide a seating surface, and a collapsed, closed position. The seat surface member includes a central seating surface member fixed to the seat base member that has an outer perimeter, and a pair of oppositely disposed and generally u-shaped seating surface members pivotally secured to the seat base member. Each of the generally u-shaped seating surface members include a pair of leg portions that extend from a base portion thereof, or an inward directed perimeter and a portion of each inward directed perimeter has a shape that substantially complementarily corresponds to a shape of a portion of the outer perimeter of the central seating surface member.

An ergonomic chair (300) comprising a seat (310), a lower leg support (320), a chest support (330), and a hip support (360); the seat (310) for supporting the posterior thigh (11) and/or buttocks (12) of a seated user (10), the seat (310) being configured to urge the hip of a seated user (10) in a forward direction; the lower leg support (320) for supporting the anterior side of the lower legs (14) of the seated user (10); the chest support (330) for supporting the chest (15) of the seated user (10) in a forward leaning position of the seated user (10); the hip support (360) is configured to support the anterior hip of a seated user (10) as the seat (310) urges the seated user's (10) hip forwardly towards the hip support (360).