Patent attributes
A cordless blind includes a headrail, a bottom rail suspended from the headrail by a first cord and a second cord, a wall covering disposed between the headrail and the bottom rail, and a drive actuator. The drive actuator includes a spring motor, a spool coupled to the spring motor, a first tensioning mechanism, and a second tensioning mechanism. The first and second tensioning mechanisms are configured to impact a resistant force on movement of the first and second cords. The drive actuator may include a spool, a spring motor, a biasing element configured to provide a force biased against movement of the bottom rail, and a bias relief mechanism that is configured to provide for selective application and relief of the biasing force by the biasing element. The drive actuator may include a constant biasing element, a generally rigid strap, a mandrel, a biasing member, and a traction wheel including a plurality of cogs extending from the circumference of the traction wheel such that movement of the strap rotates the traction wheel.
