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Systems for maintaining window covers

DC
  • US 9,359,814 B2
  • Filed: 06/01/2015
  • Issued: 06/07/2016
  • Est. Priority Date: 11/04/1997
  • Status: Expired due to Term
First Claim
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1. A window cover system, comprising:

  • a housing;

    an extendable window cover that is coupled to the housing;

    at least one lift cord to facilitate movement of the window cover between the extended position and the retracted position;

    a first cord spool;

    a spring drive system disposed within the housing, wherein the spring drive system comprises at least one spring having a storage end that is operably coupled to a storage spool and an output end that is operably coupled to an output spool, and wherein the spring drive system applies a spring force to the at least one lift cord; and

    a transmission for tailoring the spring force to a varying weight of the window cover as the window cover is moved between the extended position and the retracted position;

    wherein;

    the lift cord extends to the window cover; and

    the spring drive system has an output that controls tension on the first cord spool and no external hand-operated control cord as an input used to raise and lower the window cover.

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