Patent ID: 8167374

Claim:
In a swivel chair comprising a seat, and a supporting structure for supporting said seat on a surface, said supporting structure including a swivel-mounting assembly by which said seat may be rotated relative said supporting structure, said swivel-mounting assembly having a lower support plate, and an upper swivel-plate, and bearing means for rotatably mounting said upper swivel-plate to the said lower support plate, said lower support plate and said upper swivel-plate defining an annular gap therebetween cooperating with the interior of said swivel-mounting assembly, wherein the improvement comprises: an annular gasket having a first portion positioned in-between the lower support plate and the upper swivel-plate, the first portion having means for receiving the bearing means, the annular gasket further having a second portion depending from the first portion, the second portion being defined to include upper and lower sections extending from the first portion and having an inside facing section being in at least partial surface-to-surface contact with the lower support plate and the upper swivel-plate, whereby said annular gasket prevents foreign particles from entering into the interior of said swivel-mounting assembly without impeding the rotational movement of said upper swivel-plate.