Slat angle adjusting device for venetian blind

A slat angle adjusting device for Venetian blind comprising:

• a body;
• a roller rotatably attached to the body for a cord being wound around the roller and having two notches defined in opposite sides of the roller to respectively hold in place two knots formed on the cord;
• a transmission device received in the body and operationally connected to the roller;
• a positioning bar integrally formed on a top of the body and having two forked ends adapted to engage with upper bent portions of a headrail of the Venetian blind, each forked end having an upper tongue adapted to abut a top of the corresponding one of the bent portions of the headrail and a lower tongue adapted to abut a bottom of the corresponding one of the bent portions of the headrail;
• a recess defined in each respective side of the roller and communicating with the corresponding one of the notches in the roller to engage with the cord so as to hold the cord in place;
• and
• a protrusion formed on an inner side of each respective recess to keep the cord from releasing from the recess,
• wherein the lower tongue of each one of the forked ends has a length shorter than a half of a length of the upper tongue of the forked end.