Office chair

摘要

An office chair has separate seat (2) and pedestal (3) sections. They are joined by a first metal piece of a connecting element (1) electrically in contact with the seat section and a second part in contact with the earthed pedestal. There is a resistor (4) between the two parts. The second part is a metal tube and the first part is a tube sliding inside it but electrically insulated from it apart from the above-mentioned resistor. The first tube has a spring around a piston rod with a bearing at the bottom. This bearing is an axial one whose upper and lower discs are electrically in contact with the seat section through the piston rod.