Operating system for an architectural covering

An operating system for an architectural covering, comprising:

• a pulley wheel having a circumference and a cavity formed in the circumference;
• a drive cord formed in a loop around the circumference of the pulley wheel and operative to rotate the pulley wheel, the drive cord having a length that is a non-whole number multiple of the circumference of the pulley wheel;
• and
• a stopper attached to the drive cord and receivable in the cavity, wherein
• when the stopper coincides with the cavity, the cavity accommodates the stopper without inhibiting rotation of the pulley wheel, and
• when the stopper does not coincide with the cavity, the cavity does not accommodate the stopper and the stopper inhibits rotation of the pulley wheel.

An operating system for an architectural covering, comprising:

• a pulley wheel having a plurality of circumferentially-spaced pockets, at least one pocket of the plurality of circumferentially-spaced pockets enlarged relative to a remainder of the plurality of circumferentially-spaced pockets;
• a looped ball chain operatively engaged with the pulley wheel and including a plurality of balls that is a non-whole number multiple of the plurality of circumferentially-spaced pockets;
• and
• a stopper attached to the ball chain, wherein
• the at least one pocket is adapted to receive the stopper to permit rotation of the pulley wheel, and
• the remainder of the plurality of circumferentially-spaced pockets are adapted to not receive the stopper to inhibit rotation of the pulley wheel.