Patent ID: 6644373
Filing Date: 2003-11-11
Classification: E06B

Abstract:
A window covering system, comprising:a window covering material located between a head rail and a bottom rail, the bottom rail being connected to the head rail by a pair of lifting cords; and a pair of first biasing devices located within one of the head rail and the bottom rail, the first biasing devices having fixed ends operatively secured to the head rail or bottom rail and free ends that are free to move in a direction along an axis of the head rail or bottom rail, wherein the pair lifting cords are operatively connected to the free ends of the first biasing devices so that movement of the bottom rail in a vertical direction causes a corresponding movement in the free ends along the direction of the axis of the head rail or bottom rail, and wherein the free end of each first biasing device includes a roller, and at least one of the cords is operatively connected to each roller.