Wand construction for vertical venetian blinds

Claim 1

In a vertical type Venetian blind, including a header element forming a track supporting a plurality of depending vane elements for lateral translational movement within said track, and rotational movement about the principal axes of said vane elements, said vane elements being interconnected by a single ball chain at each of two spaced points on each vein element, improved means for communicating manually imparted movement by a user to said ball chain for rotating said vane elements, said means comprising: a vertically depending shaft supported by said header element, a pair of generally cylindrical pulley members rotatably positioned upon said shaft, each pulley member having a surface defining recesses corresponding to the shape of said ball chain, whereby when said surfaces are placed in juxtaposed relation, a single shaped curvilinear channel accommodating said chain is formed; resilient means carried by said shaft for urging said surfaces to said juxtaposed relation; a generally U-shaped clip having means thereon engaging said one of said pulley members, and a manually engageable elongated wand having means at an upper end thereof; pivotally engaging said clip means to form a flexible joint for the transmission of rotational motion therethrough; said one of said pulley members being axially shiftable along said shaft against said resilient means to permit slippage of said one of said pulley members relative to an entrained segment of said chain upon the occurrence of excessive transmitted torque to prevent damage to said blind.