Provided is an unprecedented chair in which movement of a seat by using a rolling surface can be smoothly performed.

The chair includes an upper base unit 31 and a lower base unit 32 facing each other, and a seat 1 that is provided in the upper base unit 31 and swings when the upper base unit 31 rolls with respect to the lower base unit 32, and the upper base unit 31, which is at least one of the upper base unit 31 and the lower base unit 32, includes a rolling surface 312a being curved. In the chair, a region having a different curvature exists in a part of the rolling surface 312a, and an elastic member 33 is interposed between the region having the different curvature and a corresponding region of an opposing surface.

Provided is an unprecedented chair in which movement of a seat by using a rolling surface can be smoothly performed.

The chair includes an upper base unit 31 and a lower base unit 32 facing each other, and a seat 1 that is provided in the upper base unit 31 and swings when the upper base unit 31 rolls with respect to the lower base unit 32, and the upper base unit 31, which is at least one of the upper base unit 31 and the lower base unit 32, includes a rolling surface 312a being curved. In the chair, a region having a different curvature exists in a part of the rolling surface 312a, and an elastic member 33 is interposed between the region having the different curvature and a corresponding region of an opposing surface.

Provided is an unprecedented chair in which a space between swinging surfaces facing each other can be appropriately hidden. The chair includes swinging surfaces (rolling surfaces) 312a and 322a facing each other, and has a configuration in which the swinging surfaces 312a and 322a swings with respect to each other in directions of 360 degrees including front-rear and left-right directions. In such a chair, an elastic member 33 is arranged to be positioned between the swinging surfaces 312a and 322a at least in the vicinity of outer peripheral edges 312z and 322z, and a stretchable sheet material 60 is provided between the outer peripheral edges 312z and 322z to conceal a gap between the swinging surfaces 312a and 322a facing each other, the gap including the elastic member 33.

Provided is an unprecedented chair in which a space between swinging surfaces facing each other can be appropriately hidden. The chair includes swinging surfaces (rolling surfaces) 312a and 322a facing each other, and has a configuration in which the swinging surfaces 312a and 322a swings with respect to each other in directions of 360 degrees including front-rear and left-right directions. In such a chair, an elastic member 33 is arranged to be positioned between the swinging surfaces 312a and 322a at least in the vicinity of outer peripheral edges 312z and 322z, and a stretchable sheet material 60 is provided between the outer peripheral edges 312z and 322z to conceal a gap between the swinging surfaces 312a and 322a facing each other, the gap including the elastic member 33.

The chair has a simple structure in which a seat can follow a free movement of a seated person in front-rear, left-right, and diagonal directions, a burden from an operation by which the seated person balances his or her load can also be reduced, and a movement by which the seated person changes his or her posture stably and continuously can be suitably supported. The chair includes a movement mechanism 3 that causes an upper base unit 31 to swing in a direction of 360 degrees with respect to a lower base unit 32, and a seat 1 attached to the upper base unit 31. The chair further includes a damper mechanism DM that may operate by following a movement in a direction of 360 degrees, as a mechanism separate from the movement mechanism 3, at a position connecting the upper base unit 31 and the lower base unit 32.

The chair has a simple structure in which a seat can follow a free movement of a seated person in front-rear, left-right, and diagonal directions, a burden from an operation by which the seated person balances his or her load can also be reduced, and a movement by which the seated person changes his or her posture stably and continuously can be suitably supported. The chair includes a movement mechanism 3 that causes an upper base unit 31 to swing in a direction of 360 degrees with respect to a lower base unit 32, and a seat 1 attached to the upper base unit 31. The chair further includes a damper mechanism DM that may operate by following a movement in a direction of 360 degrees, as a mechanism separate from the movement mechanism 3, at a position connecting the upper base unit 31 and the lower base unit 32.

Disclosed herein is a cylindrical rocker mechanism including a top assembly having a first cavity, a middle assembly including at least one middle lug aligned with the first cavity to facilitate insertion of a first pin therethrough thereby coupling the top assembly with the middle assembly, a second cavity aligned perpendicularly to the at least one middle lug, a bottom assembly having a horizontal plate, and at least one bottom lug aligned with the second cavity to facilitate insertion of a second pin therethrough thereby coupling the top assembly with the middle assembly, wherein the top, and middle assemblies move and roll in perpendicular directions thereby facilitating a friction dependent, substantially slip-less, omnidirectional, rolling and a tilting motion of the top assembly in response to a force applied by a subject to top assembly.

Disclosed herein is a cylindrical rocker mechanism including a top assembly having a first cavity, a middle assembly including at least one middle lug aligned with the first cavity to facilitate insertion of a first pin therethrough thereby coupling the top assembly with the middle assembly, a second cavity aligned perpendicularly to the at least one middle lug, a bottom assembly having a horizontal plate, and at least one bottom lug aligned with the second cavity to facilitate insertion of a second pin therethrough thereby coupling the top assembly with the middle assembly, wherein the top, and middle assemblies move and roll in perpendicular directions thereby facilitating a friction dependent, substantially slip-less, omnidirectional, rolling and a tilting motion of the top assembly in response to a force applied by a subject to top assembly.

A seat device that can reliably prevent a rotation operation of a seat by a seated person, in a long state where the back of the seat is along a wall. A rotation lock mechanism (60) that can restrain the rotation of a seat (1), a rotation operation unit (200) that performs a release operation of restraint by the rotation lock mechanism (60), and a rotation operation prevention mechanism (210) that disables the release operation in the rotation operation unit (200), when the seat (1) is in the long state are included. The rotation operation prevention mechanism (210) includes an engaging unit (211) provided in the leg stand (11), and an engaged unit (207) that is provided in the rotation operation unit (200) in the movable stand (20), and disables the release operation in the rotation operation unit (200) by being engaged with the engaging unit (211) when the seat (1) is in the long state.

A rotating work surface system for a chair including a seat base having a top engaging surface, a seat support having top side and a bottom side and a rotating surface positioned in between the seat base and the seat support. The rotating surface includes a top side and a bottom side wherein the rotating surface is adapted to pivotally engage about an axis and a fixed position of the seat base and the seat support.