Patent ID: 7341091

Claim:
A control device for Venetian blinds to control the hiding condition of a window covering of a Venetian blind, said control device comprising: a positioning unit fixed on an upper rail of said Venetian blind; a rope control unit consisting of a wind wheel, a rope, an engage wheel and a clutch, said wind wheel rotatably connected to said position unit, said rope having one end fixed tightly with said wind wheel and the other end hanging down for a user to hold for handling, said wind wheel rotated by said rope, said engage wheel fitting with said wind wheel and fixed tightly with said window covering, said clutch connected with said wind wheel and said engage wheel, said wind wheel and said engage wheel rotating in the same direction in case said wind wheel rotates said clutch in a first direction, said wind wheel and said engage wheel rotating in different direction in case said wind wheel rotates said clutch in a second direction; and a movement control unit connected pivotally to said positioning unit, having a lever member beside said engage wheel and moved by said rope to engage with or disengage from said engage wheel for controlling an upwardly and downwardly movement of said window covering, wherein said engage wheel includes a ratchet and a connecter, said ratchet having many inclined teeth in the same direction and a fitting hole formed in the center; said connecter has a connect stage, an actuating stage and fitting stage, said connect stage connected to said wind wheel by fitting, said actuating stage fitting around by said clutch, said fitting stage fitting in said fitting hole to let said ratchet rotating with said connecter, wherein said engage wheel has a one-way coil spring, which has one end fixed with said connecter and the other end fixed on said ratchet, so said connecter may rotate in the same direction as said ratchet does, and also in the reverse direction from said ratchet.