Anti=drop safety mechanism for up=and=over door e.g. of garage

摘要

The safety mechanism, designed for an up-and-over door (2) which slides vertically and has a counterweight (11) connected to it by a cable (12) passing over a pulley (14), consists of a catch (16) which is pivoted to the door and engages with stops (24) on the door frame in the event of cable failure. The catch is counterweighted by a lever (20) which is connected to the cable by a sliding coupling (22) to hold the catch in the unlocked position during normal operation. If the cable brakes or gives way the lever tilts the catch into its deployed position where it can engage with one of the stops and prevent the door from dropping. In variants of the design the catch lever can have a counterweight or be made in the form of a springloaded hook.