US Patent 10329836 Window covering positional adjustment apparatus

A window covering includes a positional adjustment mechanism connected to a first rail that includes a spring motor unit, a first lift cord pulley connected to the spring motor unit, a first lift cord collection mechanism having a first roller positioned in the first rail, and a first lift cord that extends from the first lift cord pulley through window covering material such that a portion of the first lift cord passes along the first roller. The first roller is configured so that it only rotates a pre-selected number of revolutions when the window covering material is moved from the extended position to the retracted such that the first roller no longer rotates in the second rotational direction as the window covering material is moved from an extended position to a retracted position after having rotated the pre-selected number of revolutions in the second rotational direction.