Safety device for cord-operated control system

A cord-operated control system (1, 101, 201, 301, 401, 501, 601, 701) for a covering for an architectural opening, such as a venetian blind, which includes:

• a housing (3, 103, 03, 303, 403, 503, 603, 703);
• a first drive wheel (7, 107, 207, 307, 407, 507, 607, 707) that is operatively connected to a driven bind member (5A), adapted to rotate in opposite directions to open and close the covering;
• the first drive wheel being adapted to rotate in opposite directions and being connected to the driven blind member, so that the driven blind member rotates with the first drive wheel;
• a second drive wheel (9,109,209, 309, 409, 509, 609,709) that is adapted to rotate in opposite directions within the housing, is rotatably connected to the housing (3,103,203, 303, 403, 503,603,703) and is operatively connected to the first drive wheel (7,107,207, 307, 407, 507, 607,707), so that the first drive wheel rotates with the second drive wheel;
• and
• an operating cord (11,111,211, 311, 411, 511,611,711) that is an endless loop and is looped over the second drive wheel (9,109,209, 309, 409, 509,609,709) and has first and second, cord portions (31,131,231, 331, 431, 531,631,731 and 33,133,233, 333, 433, 533,633,733) depending from opposite sides of the second drive wheel, whereby an axial pulling force on only the first cord portion causes the second drive wheel to rotate in a first direction and an axial pulling force on only the second cord portion causes the second drive wheel to rotate in an opposite second direction;
• and
• release means (24A, 25A, 124A, 125A, 224A, 225A, 324A, 325A, 424A, 425A, 571, 573, 587, 589, 687, 689, 691, 693,800) for disconnecting, preferably non-destructively disconnecting, the second drive wheel (9,109,209,309,409, 509, 609,709) from the first drive wheel (7,107,207, 307, 407,507, 607,707) only when there is an axial pulling force on both the first and second cord portions (31,131,231, 331, 431, 531, 631,731 and 33,133, 233, 333, 433, 533, 633, 733) simultaneously.