US Patent 7325279 Cord-releasing safety device for window blind

A cord-releasing safety device includes a casing having a receiving space extending from top to bottom open-end portions thereof, a damping seat inserted into the receiving space and slidable upward and downward relative to the casing, a limiting unit associated with the top open-end portion and the damping seat to limit upward and downward movement of the damping seat relative to the casing, an urging element disposed in the receiving space for urging the damping seat to move upward, and a coupling member connected detachably to a lower connecting portion of the damping seat and adapted to be connected with a pull cord of the window blind.