US Patent 7234203 Locking hinge for folding ladder

A hinge for a folding ladder including a hinge latch movable between a locked position and an unlocked position disposed within a hinge latch cavity. The hinge latch includes a first locking portion protruding therefrom, an elongated slot formed configured to slidingly receive a hinge shaft, a first opening configured to receive a first biasing member, and a second opening configured to receive a locking member. Rotational movement of one hinge casing relative to another hinge casing is prevented by engagement of the first locking portion and locking member with a respective one of the first opening and second opening.