Roller shaft for office chair, has ring groove surrounded by S-shaped twisted lock ring whose curved upper and lower ends are supported at upper and lower groove walls and outer edge is elastically supported at lock wall

摘要

The shaft has an upper end with a ring groove (300) that exhibits upper and lower groove walls (301, 302). The ring groove is surrounded by an S-shaped twisted lock ring (4). Curved upper and lower end of the lock ring are supported at the upper and lower groove walls and outer edge of the lock ring is elastically supported at a wall of a lock. The lock is provided for inserting a roller axle at a leg of a chair.