Patent ID: 6129131
Filing Date: 2000-10-10
Classification: E06B

Abstract:
An apparatus for moving a covering across an architectural opening, said apparatus comprising in combination,a lift system operatively associated with said covering to move said covering in at least one direction across said opening, anda pull system operatively associated with said lift system to cause said lift system to move said covering across said opening, said pull system including a substantially cylindrical rotatable drive member and means for rotating said drive member, a cavity having a substantially cylindrical fixed surrounding wall, and a substantially cylindrical driven member of slightly smaller diameter than said drive member rotatably mounted between said drive member and surrounding wall in axial alignment therewith, and a coil spring having a relaxed internal diameter and external diameter, said coil spring being coaxial with said drive member, said driven member and said surrounding wall, said drive member having a diameter slightly greater than the relaxed internal diameter of said coil spring, said surrounding wall having a diameter slightly smaller than said relaxed outer diameter of said coil spring such that said coil spring is frictionally engaged with said drive member and surrounding wall in its relaxed state but slightly spaced from said driven member, whereby upon rotative movement of said drive member in a first direction the coil spring will become reduced in diameter and frictionally grip said driven member before losing its frictional engagement with said surrounding wall thereby causing said driven member to rotate in unison with said drive member and upon rotative movement of said drive member in an opposite direction the coil spring will enlarge in diameter and lose its frictional engagement with said drive member so that the drive member is free to rotate in said opposite direction without effecting rotation of the driven member, said driven member being operatively connected to said lift system so as to move said covering across said opening upon driven rotation of said driven member by said drive member.