Top bow for a collapsible roof

The flap (20) has a control mechanism (21) for moving the flap between a closed position and an opened position, where the mechanism has a four hinge lever (26) arranged in a longitudinal side of the flap. The lever has a front control rod (24) and a rear control rod (25) supported at the flap at a side and at a sliding element (29) at another side, where the sliding element is accommodated by a guide rail (23). The lever has a control device (30) for fixing the flap in the closed position and the opened position using a locking system (31) and another locking system, respectively.