Patent ID: 9574396
Date: 2017-02-21
CPC Classifications: E06B,Y10T

Claim:
1. A window cover system comprising: a housing having a longitudinal axis; an extendible window cover coupled with the housing; at least one cord to facilitate raising and lowering the window cover to any selected position between an extended position and a retracted position; a spring drive system comprising a pair of spaced apart spring drive spools and at least one flat spring having a storage end coupled to one of the spring drive spools and an output end coupled to the other spring drive spool; a wind-up spool coaxially aligned with one of the spring drive spools about a first axis for receiving the cord, wherein the cord is wrapped around the wind-up spool for assisting in raising and lowering of the cover when moved to a selected one of the positions; and a transmission for tailoring a force applied to the extendible window cover, wherein: