Meaning of aldava by Felipe Lorenzo del Río

aldava is incorrectly written, and should be written as "latch" being its meaning:
Articulated piece of metal, often in the form of hand closed, located on the exterior doors of the old houses at the height of the face to call its occupants with repeated blows. In ready ( northwestern province of Zamora ) opening doors with old locks system. These locks have a fixed on wood metal exterior handle to pull the door towards the inside or out and up a kind of mobile metal tongue that being struck down with your thumb up roll-up door that inside holds the largest gate door and opens it. Latch is called properly moving parts lock and in particular to the sort of external language which is pressed with the thumb. All these elements were made at the forge.