WINDOW COVER SYSTEM WITH SPRING DRIVE ARRANGEMENT

摘要

A spring drive system useful for window covers is disclosed, which comprises one or more coil spring drives or flat spring drives and the combination whose elements are selected from one or more of a group which includes (1) a band or cord transmission which provides varying ratio power transfer as the cover is opened and closed; (2) gear means comprising various gear sets which provide frictional holding force and fixed power transfer ratios; (3) a gear transmission which provides fixed ratio power transfer as the cover is opened or closed; (4) crank mechanisms; (5) brake mechanisms; and (6) recoiler mechanisms. The combination permits the spring drive force to be tailored to the weight and/or compression characteristics of an associated window cover such as a horizontal slat or pleated or box blind as the cover is opened and closed.

主权项

1. A window cover system comprising:
a housing; an extendible window cover coupled with the housing; at least one lift cord attached to the cover for 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 for receiving the lift cord, wherein the lift cord is wrapped around the pulley for assisting in raising and lowering of the cover when moved to a selected one of the positions; and a transmission disposed within the housing that is laterally spaced apart from the spring drive system and the wind-up spool, wherein the spring drive system, the wind-up spool, and the transmission cooperate to maintain the cover in the selected position.