Castor wheel for swivel chairs - has leaf spring brake which is automatically released by user weight

摘要

The castor wheel rotates a housing which is able to pivot on a vertical swivel pin (9) located in a bush (10) suitably fixed to the leg of a chair. A leaf spring (13) is fitted inside the caster wheel housing. One end (14) of the leaf spring is fixed between the housing side walls at their connecting strip (3) and the second end (15) supports its self against the lower side of the connecting strip close to the pivot pin bush. The leaf spring presses on the caster wheel with a pressure of 0.4 KG which together with the other four castors produce a rolling resistance of 2 kg when the chair is not in use. The leaf spring is released from contact with the caster wheel by a two armed lever (20) pivoted on a shaft (19) fixed between the two housing side walls.