SPRING-TILT MECHANISM FOR A CHAIR OR SEAT

摘要

The spring-tilt mechanism comprises a support frame (4), a seat portion (1) tiltable on the support frame (4) about a substantially horizontal axis (2) between a first and a second position, e.g. defined by stops (13, 13'). One end (15') of a torsion spring (15) is fixed against rotation in the support frame (4). A gear box (16) is operatively engaged with the other end (15'') of the torsion spring (15) and has an extendible member (24) engageable with a tracking surface (31) of the seat portion (1). An operating member (29) on the gear box (17) is easily accessible to a user sitting on the seat portion (1) to pre-load the torsion spring (15) for cushioning the user on the seat portion (1) between the said first and second positions (stops 13, 13').