| 摘要 |
The assembly has a set of bases (B1-B3), where each base is equipped at an end of a fixed wheel coupling unit (1). Multiple carriages (C1-C3) are provided with front and rear axles (2, 3) that are pivoted and bonded to each other with respect to pivot axles, where one of the bases is combined with each carriage between the pivot axles by cooperating the fixed coupling unit and a complementary coupling unit (4) by a carriage (C). The bases are provided with an additional base (B4), where the additional base is coupled to rear of one of the carriages. |
