The invention relates to a hub construction for a rotatable chair, which automatically returns to the initial position when the chair is relieved. In a prior art hub the return force was counteracted mainly by the friction in the hub bearing, which, regardless thereof that the hub was loaded, was not always sufficient for the hub to maintain its rotational position, for example, when the sitting person lifted his feet off the floor. For obtaining higher friction when the hub is loaded, it has been provided with a brake. The brake can preferably be a pair of spring discs which are compressed when the hub is loaded, whereby the brake disc makes contact with the brake surface.

A chair comprises: a leg 1 erected on a floor surface; a seat 3 arranged above the leg 1; and a support mechanism 8 interposed between the leg 1 and the seat 3, wherein the support mechanism 8 is arranged below the seat 3 and is configured to movably support the seat 3 along a predetermined trajectory by having an omnidirectional connection unit 72 configured to operably connect in all directions including the front-rear direction and the left-right direction, comprises: a seat inclining function configured to downwardly incline a tip side in a movement direction of the seat 3, and further comprises: a return-force generation mechanism configured to generate, by elevating a center of gravity of the seat 3, a return force in a direction of returning the seat 3 to the reference position.

A chair comprises: a leg 1 erected on a floor surface; a seat 3 arranged above the leg 1; and a support mechanism 8 interposed between the leg 1 and the seat 3, wherein the support mechanism 8 is arranged below the seat 3 and is configured to movably support the seat 3 along a predetermined trajectory by having an omnidirectional connection unit 72 configured to operably connect in all directions including the front-rear direction and the left-right direction, comprises: a seat inclining function configured to downwardly incline a tip side in a movement direction of the seat 3, and further comprises: a return-force generation mechanism configured to generate, by elevating a center of gravity of the seat 3, a return force in a direction of returning the seat 3 to the reference position.

A resettable pressure bar module includes a pressure bar, a rotation element, and a resetting element. The pressure bar includes an outer tube, an upper sealing element, and a lower sealing element. The upper sealing element and the lower sealing element are disposed in the outer tube and respectively disposed on the opposite two sides of the outer tube. The rotation element is fixed to the outer tube and the lower sealing element through a fixing element. One side of the resetting element includes a first guiding slope and a second guiding slope. The pressure bar passes through the resetting element. The rotation element is configured to rotate to a normal position along the first guiding slope or the second guiding slope.

A sitting device that encourages the active engagement of the user to remain upright. A seat (14) supported by a central column (12) passes through a pivot joint (16) supported by a base (10). The pivot joint (16) is located substantially at the median of the central column (12) between the seat (14) and the bottom of the base (10). The central column (12) pivots angularly providing the user mobility in his or her hips and lumbar, thoracic, and cervical spine. The central column (12) and seat (14) are brought back to vertical when the sitting device is not in use by means of a counterweight (18) affixed to the bottom of the central column (12). The length of the central column (12) may be adjustable to allow the user to select the desired height of the seat (14). The pivot joint (16) may be a spherical plain bearing, spherical ball bearing, gimbal bearing, spherical thrust bearing, or other device that allows the central column (12) to pivot angularly. The base (10) supporting the pivot joint (16) and central column (12) may contain as few as one leg and as many legs as needed to support the user. The movement of the pivot joint (16) may be inhibited by affixing a collar lock (40). The frictional resistance of the pivot joint (16) may be adjusted with a set screw (50).

A chair has a base and a support articulated thereon. The support is coupled to a seat and supports the seat. The seat is connected to the support rotatably or pivotably around a rotation axis between a sitting position and a raised position, and the support has at least one receiving region for aligned abutment of a juxtaposed chair of identical design. Provision is made in this context that in the raised position, the seat is pivoted out of the receiving region of the support and exposes the receiving region. The result is to create a chair that, for storage, can be juxtaposed in space-saving fashion with chairs of identical design.

A resistive motion support mechanism joined to a mounting surface and to a base 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 comprising: a support bearing connected to the mounting surface and to the base which permits one or both of tilting and rotational motion of the mounting surface relative to the base; a resistance cartridge fixedly connected to the mounting surface such that the resistance cartridge undergoes movement relative to the base and applies a resistive force on the base as the mounting surface undergoes the one or both of rotational and tilt movement. The mounting surface and the resistance cartridge are connected by at least one sensor for measuring one of forces applied by the mounting surface on the resistance cartridge, movement of the mounting surface with respect to the cartridge and/or acceleration of the mounting surface with respect to the cartridge.

A sitting device that encourages the active engagement of the user to remain upright. A seat (14) supported by a central column (12) passes through a pivot joint (16) supported by a base (10). The central column (12) pivots angularly providing the user mobility in his or her hips and lumbar, thoracic, and cervical spine. The central column (12) and seat (14) are brought back to vertical when the sitting device is not in use by means of a counterweight (18) affixed to the bottom of the central column (12). The length of the central column (12) may be adjustable to allow the user to select the desired height of the seat (14). The pivot joint (16) may be a spherical plain bearing, spherical ball bearing, gimbal bearing, spherical thrust bearing, or other device that allows the central column (12) to pivot angularly. The base (10) supporting the pivot joint (16) and central column (12) may contain as few as one leg and as many legs as needed to support the user. The movement of the pivot joint (16) may be inhibited by affixing a collar lock (40). The frictional resistance of the pivot joint (16) may be adjusted with a set screw (50).

A resettable pressure bar module includes a pressure bar, a rotation element, and a resetting element. The pressure bar includes an outer tube, an upper sealing element, and a lower sealing element. The upper sealing element and the lower sealing element are disposed in the outer tube and respectively disposed on the opposite two sides of the outer tube. The rotation element is fixed to the outer tube and the lower sealing element through a fixing element. One side of the resetting element includes a first guiding slope and a second guiding slope. The pressure bar passes through the resetting element. The rotation element is configured to rotate to a normal position along the first guiding slope or the second guiding slope.

A student desk promoting brain-based movement. The student desk provides a frame carrying a table and a seat and a combination of one or more features designed to allow productive movement that stimulates and enhances cognitive learning. Various aspects of the student desk include semispherical seating surface, a rotatable seat with twist resistance, a cushioned seating surface, a height adjustable table, a sensory strip on the bottom of the table, and resistance bands secured to the frame. These enhancements provide a number of different outlets for students to release nervous energy in a non-disruptive manner while remaining focused on educational activities. These enhancements allow knowledge instruction to be combined with brain-based movement, which generates increased brain activity during learning scenarios, empowers students to self-regulate emotions without disrupting class, and creates opportunities for students to enhance academic performance by developing more adaptive cognitive relationships with the academic material. The student desk is particularly well-suited for use by special needs learners and other students requiring or benefiting from physical stimulation or tactile stimulation.