| 摘要 |
A scissors-type lift assembly including a base and a platform, the lift assembly having extended and contracted states, with the platform at a relatively greater distance from the base in the extended state than in the contracted state. The lift assembly includes a pair of scissor arms each having opposed first and second ends, and pivotably connected to each other about a central axis located between their respective first and second ends, the first end of each scissor arm coupled to the base, the second end of each the scissor arm coupled to the platform. The lift assembly also has a drive screw mechanism including a shaft, a drive motor rotatably coupled to the shaft, a block threadedly engaged with the shaft and having longitudinal movement relative to the shaft, and a collar relative to which the shaft is rotatable and longitudinally fixed relative to the shaft. The lift assembly includes first and second pairs of crossed links, each link having opposed first and second ends between which extends an edge that faces away from the central axis and defines a recess in the link. The collar and block are each spaced from the central axis and indirectly coupled to both of the pair of scissor arms through a pair of links.
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