Patent ID: 8544957

Claim:
A chair comprising: a supporting structure; a seat moveably mounted on the supporting structure, wherein the seat is moveable with respect to the supporting structure in a vertical direction, wherein the seat includes a seat frame, a sitting element and a connecting member, with the seat frame including a base and a lateral wall extending upwardly from the base, with the sitting element including a top surface, a bottom surface opposite to the top surface and a peripheral edge extending laterally along circumferential edges of the top and bottom surfaces, with the connecting member mounted to the bottom surface of the sitting element, with the sitting element fixed to and disposed on the seat frame by mounting the bottom surface of the sitting element on the seat frame; a backrest including a first frame pivotally connected to the seat and a second frame separate from and pivotally mounted on the first frame to connect to the seat; and a first control device mounted and concealed between the first and second frames in order to prevent a user from inadvertently colliding with the first control device, wherein the first control device is adjusted for various relative pivotal positions of the first and second frames; wherein the lateral wall of the seat frame defines a first lateral wall section and a second lateral wall section, with the first lateral wall section including a first recessed area formed thereof and the second lateral wall section including a second recessed area formed thereof, respectively, with the first recessed area including a first depth extending in a direction transverse to a direction that directs from a proximal end to a distal end of the first lateral wall section, with the second recessed area including a second depth extending in a direction transverse to a direction that directs from a proximal end to a distal end of the second lateral wall section.