Abstract: A drop-catch mechanism for preventing the door leaf of an overhead door from rapidly closing upon breakage of the balancing spring thereof. The drop-catch mechanism having an input member for coupling with the balancing spring of the overhead door, a ratchet wheel for coupling with a winding axle carrying the door leaf of the overhead door, a pawl, and a positive mechanical drive for moving the pawl from a free position that allows rotation of the ratchet wheel to a catching position that blocks rotation of the ratchet wheel, the positive mechanical drive being configured such that, in use, breakage of the balancing spring coupled to the input member causes the pawl to move from the free position to the catching position.

Abstract: A drop-catch mechanism for preventing a door leaf of an overhead door from falling down upon breakage of a balancing spring thereof, the mechanism comprising an input member for coupling with a balancing spring of the overhead door, a ratchet wheel for coupling with a winding axle carrying the door leaf of the overhead door, a pawl, and means for moving the pawl from a free position that allows rotation of the ratchet wheel to a catching position that blocks rotation of the ratchet wheel, the means for moving the pawl being configured such that, in use, breakage of a balancing spring coupled to the input member causes the pawl to move from the free position to the catching position, characterized in that the means for moving the pawl from the free position into the catching position comprise a positive mechanical drive extending from the input member to the pawl.