A Venetian blind comprising:
- a hollow horizontal headrail;
- an upper slat unit including a plurality of parallel upper slats disposed under and parallel to said headrail, each of said upper slats having two end portions that are opposite to each other along a longitudinal direction of a respective one of said upper slats, each of said end portions being formed with a hole therethrough;
- a lower slat unit including a plurality of parallel lower slats disposed under and parallel to said upper slats, each of said lower slats having two end portions that are opposite to each other along a longitudinal direction of a respective one of said lower slats, each of said end portions of said lower slats being formed with a hole therethrough;
- a bottom rail disposed under and parallel to said lower slats, and having two end portions that are opposite to each other with respect to a longitudinal direction of said bottom rail;
- two pull ropes extending respectively through said holes in each of said upper and lower slats and passing through said headrail, each of said pull ropes having a mounting end that is fastened to a respective one of said end portions of said bottom rail, and an actuator end that is opposite to said mounting end and that is suspended from said headrail, said actuator end being actuatable to adjust raising and lowering of said upper and lower slats;
- a first angle-adjusting mechanism including
- a first rotating shaft journalled within said headrail and extending along a longitudinal direction of said headrail,
- a first adjustment rod connected operatively to said first rotating shaft and capable of being actuated to rotate said first rotating shaft, and
- two first positioning cord units mounted respectively on two end portions of said first rotating shaft and connected respectively to said end portions of each of said upper slats, each of said first positioning cord units including
- two first ladder cords that have upper ends secured to said first rotating shaft and that abut respectively against two opposite longitudinal sides of each of said upper slats, and
- a plurality of parallel first slat-supporting cords, each of which is disposed under a respective one of said upper slats, and has two opposite ends that are disposed respectively at said longitudinal sides of each of said upper slats and that are fastened respectively to said first ladder cords;
- and
- a second angle-adjusting mechanism including
- a second rotating shaft journalled within said headrail and extending along the longitudinal direction of said headrail,
- a second adjustment rod connected operatively to said second rotating shaft and capable of being actuated to rotate said second rotating shaft, and
- two second positioning cord units mounted respectively on two end portions of said second rotating shaft and connected respectively to said end portions of each of said lower slats, each of said second positioning cord units including
- two second ladder cords that have upper ends secured to said second rotating shaft, and that abut respectively against two opposite longitudinal sides of each of said lower slats, and
- a plurality of parallel second slat-supporting cords, each of which is disposed under a respective one of said lower slats and has two opposite ends that are disposed respectively at said longitudinal sides of each of said lower slats and that are fastened to said second ladder cords;
- whereby, tilting angle of said upper slats can be adjusted independently from that of said lower slats;
- wherein each of said first ladder cords has a lower end that is located above said lower slats, said first angle-adjusting mechanism further including a counterweight strip which is disposed under a lowermost one of said upper slats and which has two end portions that are fastened to said lower ends of said first ladder cords, said bottom rail being fastened to lower ends of said second ladder cords, thereby serving as a counterweight;
- and
- a clamping unit for clamping together said lower ends of said first ladder cords, said counterweight strip, and said lowermost one of said upper slats.