A virtual device for the limited pivoting of an object about a base virtual pivot point by means of a pivoting device, where a limiting device is provided for the pivoting angle. The virtual device is a mechanically stable and yet space-saving limiting device that is rotatable about an outer axis on the base and about an outer axis (23′) rotatable on the object, or on the slide, where the limiting device limits the distance and/or the angular position of the two axes relative to one another, with the proviso that the axes always occupy the same plane.

A seat has a supporting frame being rigid, two seat cushions disposed above the supporting frame, and two supporting members. The supporting frame has a main body and four side bodies fixedly mounted on two front ends and two rear ends of the main body. The supporting members are mounted on bottom surfaces of the seat cushions and are connected to the supporting frame. Each one of the supporting members has multiple supporting elements respectively located at a front half section and a rear half section of a corresponding one of the seat cushions. Each one of the supporting elements has a guiding rod mounted on the supporting frame and a main spring disposed around the guiding rod. The seat provides good support by the supporting frame and the supporting members and provides a cushioning performance by the main spring.

There is provided an ergonomic chair which is produced from flat components. The components may be made of paper. The components are designed using parametric equations which take the targeted user's proportions into account. The components are then folded, joined, and coated with strengthening material. The chair has a seat, a base, and three legs connecting the seat to the base. The base contains a counterweight mass for keeping the chair in a default upright position. The base contains an accelerometer which can transmit data to a computing device to track a user's posture and other health-related data.

In one aspect, an active exercise chair comprising seat support, wherein the seat support is rigidly affixed to a top section of a shaft of the gas spring; a seat, wherein the seat is connected to the seat support; a seatback support, wherein the seatback support is pivotably connected to the seat support about a discrete pivot point; a seatback carriage, wherein the seatback carriage is slidably connected to the seatback support, wherein the seatback carriage is connected to a seatback, and wherein the seatback traverses a translational path defined by the geometry of the seatback carriage and the seatback support.

A chair according to the present invention has a reference position P located midway in a front-back direction in a movable range of a seat 2. The chair includes a return force generation mechanism 4 configured to generate a return force in a direction to return the seat 2 moved from the reference position P at least in the front-back direction to the reference position P. The return force generation mechanism 4 includes an elastic member 40 configured to increase the return force in the direction to return the seat to the reference position P as the amount of movement of the seat from the reference position P increases.

A seat for hip shaking is set on a surface of a chair while in use. The seat for hip shaking includes a seat member and a base member arranged under the seat member. A top surface of the seat member is disposed with a saddle-shaped seat surface for users to sit thereon while a spherical surface is projecting downward from a bottom surface of the seat member. The base member has at least one support part on a top surface thereof. The spherical surface of the seat member is moveably supported by the support part of the base member and is rotated at an arbitrary angle. When a user sits on the saddle-shaped seat surface, he/she shakes the hip or maintains the balance to get the benefits of exercise like horse riding.

Office, work and leisure chair and retrofit kit for causing subliminal movements of the person sitting thereon. The chair has a cruciform base (1), freely articulated rollers (4), a gas-spring support (2) and an interface panel (5) resting thereon as a support panel. Mounted on the support panel is a base panel (28) bearing a seat cover (19) with a seat surface and back rest (22). The seat cover is provided and allowed to wobble, resting via a cover panel (27) on a plurality of spring elements (7), which are displaceable radially, or obliquely in relation to the radial direction, or helically from the centre of the base panel to the periphery of the base panel. The spring elements are mechanically, hydraulically, pneumatically or electrically displaceable, so that the wobble distance of the seat cover and the attenuation of the wobble movement are variable.

An office chair system has an office chair with adjustment elements for changing positions of elements of the office chair, a sensor element, a calculation unit coupled to the latter and to the adjustment elements, as well as an operating element coupled thereto. The adjustment elements are configured to detect contacts and actuations of components of the adjustment elements and to generate an adjustment signal based thereon. The sensor element is configured to determine the positions of the elements and a posture of a user and to generate a position signal based thereon. The calculation unit is configured to generate a first feedback signal based on the position signal, which contains information about a proposed change of the positions. One of the components is assigned to the proposed change. The calculation unit is configured to verify a contact or actuation of the assigned component and to generate a second feedback signal based thereon. The operating element is configured to output the first and second feedback signals.

A chair may include a base defining a vertical axis of the chair, a seat configured to support a user thereon, and a seat support assembly disposed between the base and the seat in the direction of the vertical axis. The seat support assembly may include a height adjustment assembly configured to allow the seat to translate along the vertical axis, and a wobble assembly configured to allow the seat to tilt relative to the vertical axis in a side-to-side direction. The wobble assembly may include a wobble lock having a locked configuration, in which the wobble lock inhibits tilting of the seat relative to the vertical axis in the side-to-side direction, and an unlocked configuration, in which the wobble lock allows tilting of the seat relative to the vertical axis in the side-to-side direction.

An embodiment includes a user-stabilized stool having a bottom portion for contacting a ground surface that is configured to be inherently unstable when in an active position, thereby requiring a user to stabilize the stool when in the active position. The stool further includes a seat portion connected to the bottom portion and a stabilizing member operable, when the bottom portion is in the active position, to prevent the user-stabilized stool from tilting beyond a predetermined angle.