Child safe operating wand for a blind

An operating mechanism for a screen assembly having an elongate endless pull cord hanging from the screen assembly in a loop, said operating mechanism comprising a housing having an opening at an upper end whereby at least a lower end of the pull cord is enclosed within the housing, the housing incorporating a guide for guiding passage of the pull cord through the housing, said guide incorporating a locking device adapted to selectively restrain a first or a second side of the loop defined by the pull cord within the housing as the housing is pulled downwardly with respect to the screen assembly, said guide comprising a first sprocket rotatably mounted within the housing adapted to engage a first portion of the pull cord on the first side of the loop defined thereby and a second sprocket rotatably mounted within the housing adapted to engage a second portion of the pull cord on the second side of the loop defined thereby, the locking device being adjustably configurable between a first state, wherein the locking device prevents rotation of the first sprocket as the housing is displaced downwardly with respect to the pull cord, causing the housing to pull on said first side of the loop defined by the pull cord, and a second state, wherein the locking device prevents rotation of the second sprocket as the housing is displaced downwardly with respect to the pull cord, causing the housing to pull on the second side of the loop defined by the pull cord,

• wherein the guide includes a cord retaining member engaging a lower end of the looped pull cord, said cord retaining member being moveable within the housing between vertically spaced first and second positions, said second position being above said first position, the cord retaining member being biased towards said first position by a biasing device, whereby the housing may be displaced downwardly with respect to the pull cord by virtue of upward movement of the cord retaining member between its first and second positions within the housing against the force of the biasing device,
• wherein the upper part of the housing is adapted to engage the screen assembly such that a twisting torque applied to the lower part of the housing can be transferred to the screen assembly in order to facilitate control of the locking device.