Office swivel chair with adjustable backrest - has accurate guide for backrest support hoop, transferring strain over wider area

摘要

The support structure for the seat of an office chair has a U-shaped head piece (3). Its arm (6, 7) each have at least one bead aligned towards the longitudinal axis X of the seat support and set between a hoop (10) which connects the two arms and the connections (4) for the arms on the seat support (5) in the longitudinal direction of a guide for the backrest support hoop (2). This guide is formed by the arms and the hoop. The beads together with the arms and their connecting hoop form the guide for the support hoop. An actuating handle (13) between the beads and the connections between the arms and the seat support biases the beads towards the longitudinal axis of the seat support and/or release it from this position again.