| 摘要 |
A rolling device (1) includes an axle (2) rotatable about an axis (C), a plurality of first rolling members (3), and a plurality of second rolling members (5). The first rolling members (3) are connected fixedly to the axle (2). Each of the first rolling members (3) includes a first body (30) having a first rolling surface (31) that is contactable with the ground surface and that is spaced apart from the axis (C) by a first radius (L1). Any two adjacent ones of the first rolling members (3) define an accommodating space (4) therebetween. Each of the second rolling members (5) is disposed movably within the accommodating space (4) between two adjacent ones of the first rolling members (3). Each of the second rolling members (5) includes a second body (50) having a second rolling surface (51) that is contactable with the ground surface and that is spaced apart from the axis (C) by a second radius (L2). Each of the second rolling members (5) is movable relative to the first rolling members (3) between a retracted position whereat the second radius (L2) is not more than the first radius (L1), and an extended position whereat the second radius (L2) is more than the first radius (L1). |
