Patent ID: 7341310

Claim:
An office chair having an automated height-adjustment assembly comprising: a base structure including a plurality of support legs radially extending from a central hub, said support legs each having a distal end with a caster thereon; a pan mounted on the base structure; a chair member superimposed onto said pan; a scissor lift attached to said pan and said chair wherein said scissor lift includes two opposing scissor frames, each scissor frame formed of a first arm and a second arm, each of said arms having an upper end, a lower end and an intermediate portion, said first and second arms pivotally joined at the intermediate portions; said lower end of the first arm pivotally attached to said pan, the lower end of each scissor frame second arm including an outwardly extending guide member, said guide member slidably received within an oblique, upwardly sloped channel formed on one of two opposing sidewalls of the pan to assure that said chair member remains horizontal during expansion and contraction of said scissor lift; a shaft interconnecting the lower ends of the second arms, said shaft having an internally threaded, transverse sleeve thereon; a drive screw received within said sleeve; a motor operably connected to said drive screw whereby operation of said motor results in rotation of said drive screw and axial translation of the sleeve to expand and contract the scissor lift to raise and lower the chair member.