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Elevating system

  • US 5,361,565 A
  • Filed: 01/19/1993
  • Issued: 11/08/1994
  • Est. Priority Date: 01/19/1993
  • Status: Expired due to Fees
First Claim
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1. An elevating system for raising and lowering items, comprising:

  • first support means for supporting an item to be raised and lowered;

    at least two winch means, coupled to said support means at spaced locations, for raising and lowering said support means, each of said winch means includinga cable,a winch housing,rotatably mounted drum means, coupled to said winch housing, for dispensing and retracting said cable therefrom, andsynchronous motor means for rotating said drum means; and

    control means, electrically coupled to each of said motor means, for operating each of said winch means, said control means includingsingle inverter means, electrically coupling each of said motor means in parallel, for starting and stopping said motor means by varying input frequency to slowly ramp the output of said motor means during starting and stopping of said motor means.

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