| 摘要 |
A platform ladder comprising two elongate ladder sections having feet at one end and an upper end, the upper end of each section being hinged to an upper rail, a platform pivotally secured to one ladder section below the upper end and adapted to interconnect with the other ladder section, and stays interconnecting each side of the ladder sections whereby when the ladder is in an operative position with the ladder sections assuming an erect A shaped profile with the platform extending between the ladder sections to define a standing platform, the ladder sections, upper rail and stays, define a four bar linkage.
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