| 摘要 |
A child's seat includes a base structure (20) having a central helical screw (14). A seat (26) is mounted on a shaft (28) for upward movement without rotation. Thereafter, the seat can only fall while rotating due to engagement of teeth (37), (39) respectively on a nut (38) and on the shaft (28). Latching means (50) is included to enable the seat to be retained in any one of a series of raised positions. |
