A chair includes a back member and arm brackets. The back member is tapered toward an end that is adjacent to a seat. The arm brackets are attached under a bottom portion of the seat. Each arm bracket is adjustable to provide a seat clearance area for the seat when one or more of the arm brackets are adjusted up to approximately 90 degrees from an original upright position.

An adjustable chair comprising a seat part, a seat back disposed along one side of the seat part, the seat back being configured for supporting at least a person's back or shoulders, a chair base configured for being placed on a floor, at least one adjustable chair feature including a motor capable of being selectively controlled and driven so as to adjust at least one of: the rotation or tilt of the seat part, a vertical distance between the seat back and the one side of the seat part, an angle position between the seat back and the seat part, and a distance between the chair base and the seat part.

An adjustable chair comprising a seat part, a seat back disposed along one side of the seat part, the seat back being configured for supporting at least a person's back or shoulders, a chair base configured for being placed on a floor, at least one adjustable chair feature including a motor capable of being selectively controlled and driven so as to adjust at least one of: the rotation or tilt of the seat part, a vertical distance between the seat back and the one side of the seat part, an angle position between the seat back and the seat part, and a distance between the chair base and the seat part.

A balance chair, comprising a seat, an in substance vertical height element supporting the seat, and a base supporting the height element and seat, distinctive in that the balance chair comprises a rotation and tilt element, arranged in a position in substance midway between the seat and a lower end of the base.

A balance chair, comprising a seat, an in substance vertical height element supporting the seat, and a base supporting the height element and seat, distinctive in that the balance chair comprises a rotation and tilt element, arranged in a position in substance midway between the seat and a lower end of the base.

A chair support device primarily for office use includes a lower support having rollers or feet for standing on the floor spaced apart from each other in predetermined distances, an upper support, and a receiving tube, as a support member, that has a central axis, connected to a central portion of the upper support, extends therefrom towards the lower support and is coupled to a central portion of the lower support by a ball joint that enables tilting of the receiving tube within an angular range relative to vertical and weight load to be taken predominately by the lower support. The support member is preferably in or close to the weight line of a chair held by the device.

A chair support device primarily for office use includes a lower support having rollers or feet for standing on the floor spaced apart from each other in predetermined distances, an upper support, and a receiving tube, as a support member, that has a central axis, connected to a central portion of the upper support, extends therefrom towards the lower support and is coupled to a central portion of the lower support by a ball joint that enables tilting of the receiving tube within an angular range relative to vertical and weight load to be taken predominately by the lower support. The support member is preferably in or close to the weight line of a chair held by the device.

A resistive motion support mechanism joined to a mounting surface and to a base shaft for providing resistive support to the mounting surface as the mounting surface undergoes one or both of rotational and tilt movement relative to the base, the motion support mechanism including a support bearing connected to the mounting surface and to the base shaft which permits one or both of tilting and rotational motion of the mounting surface relative to the base; a pivot ball functionally attached to a portion of the base shaft; a resilient ring within a housing circumscribing the base shaft such that the resilient member is compressed between the housing and the base shaft by the relative movement between the base shaft and the mounting surface to provide a resistive force on the base shaft to resist the one or both of rotational and tilt movement; and, various means for varying the resistive force.

A twistable chair backrest frame is disclosed herein. It has a hollow section and two opposite elastic supporting ribs at a right side and a left side of the hollow section.

The present invention relates to a single-legged portable working chair using a compression repulsive force of a spring body, wherein: when used, the telescopic single-legged portable working chair is worn on a user's body such that, when the user sits down, the spring body is compressed by the weight of the user's body to store power, and when the user stands up, the spring body pushes up the user's body using the compressed power, so that the power consumption required for the sitting and standing actions of the body can be reduced; when the user repeatedly lifts a weight, the load applied to the user's joints and muscles is alleviated by the magnitude of a repulsive force of the spring body.