| 摘要 |
PROBLEM TO BE SOLVED: To provide a wheel which can be braked at any position on a step without largely dropping a level difference in an escalator, and to provide an escalator cart which can be converted from a regular cart so as to ride over an escalator by replacing a wheel of a hand truck generally in use with this wheel. SOLUTION: A wheel largely drops the level difference in an escalator only when a previously advanced wheel is dropped by a succeeding wheel. The wheel is dropped to a lower step by itself only when the wheel is moved between steps of a small level difference. A front wheel does not drop the step by the movement of the rear wheel if the distance between the front and rear wheels is set to be 1.5 to 2.5 times the tread length of the step. A rotary shaft of the wheel is longitudinally moved when a vehicle body is tilted, and brought into contact with a brake built in a wheel frame, and the wheel is not driven even on a step corner part. COPYRIGHT: (C)2008,JPO&INPIT
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