Patent ID: 6666252
Filing Date: 2003-12-23
Classification: E06B,F16D

Abstract:
An architectural covering and a winding mechanism for controlling the retraction and deployment of the architectural covering, said winding mechanism having a winding element, about which the covering, or lift cords or tapes attached to the covering are wound and unwound with rotation of the winding element about a first axis of rotation, and a fluid brake for retarding the rotation of the winding element in at least one direction about the first axis; the fluid brake comprising a fluid-tight compartment containing a liquid and an impeller and wherein the compartment and the impeller are adapted for relative rotation about a second axis of rotation; the compartment or the impeller is operatively connected to the winding element; the liquid rotates with rotation of the compartment or the impeller about the second axis; rotation of the liquid relative to the impeller or to the compartment in at least a first direction about the second axis is effective to retard the rotation of the winding element in at least a second direction about the first axis; and the impeller or an inner peripheral wall surface of the compartment include a first surface that extends generally radially with respect to the second axis, wherein said first surface is of fan blade configuration.