Pneumatic support column for a chair

摘要

A vertically adjustable column for supporting a seat of a chair. The column includes an outer guide tube mounted to a support stand, an intermediate telescoping tube slidably positioned with the guide tube and an inner telescoping tube slidably positioned within the intermediate tube. An upper portion of the inner telescoping tube is connected to the seat. A gas spring includes a cylinder mounted within the inner tube, a piston rod extending outwardly from the cylinder and a control pin assembly mounted to an upper portion of the cylinder. The piston rod is connected to the guide tube and is extensible between a collapsed position in which the cylinder and inner tube are substantially within the intermediate tube and the intermediate tube is substantially within the guide tube, and a raised position in which a portion of the cylinder and inner tube extend outwardly from the intermediate tube and a portion of the intermediate tube extends outwardly from the outer guide tube.