| 摘要 |
Apparatus for raising and lowering objects. In accordance with some embodiments, a winch motor is adapted to rotate a winch member in opposing first and second directions to wrap/unwrap a portion of a cable on/from the winch member to raise and lower a lifting platform assembly, respectively. A tension detection switch assembly includes an on/off switch connected to the winch motor and a biasing member which exerts a bias force upon the winch member to nominally deflect the winch member to a first position which sets the switch to deactivate the winch motor in an absence of tension in the cable from the lifting platform assembly. A presence of tension in the cable from the lifting platform assembly deflects the winch member to a second position which sets the switch to facilitate activation of the winch motor.
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