| 摘要 |
An activity frame comprises a pair of supports 5 and three concentric rings, comprising an outer ring 2, a middle ring 3 and an inner ring 4, each mounted on diametrically opposed bearings 6, 7, 8 and offset from preceding bearings by 90º. The rings may be locked together with resilient 44 or flexible 43 means. Demountable attachments such as a cylindrical tub or barrel, a sphere or platform may be fixed to the inner ring to adapt the purpose of the frame. |
