Was this meant to be a technical question ?
You can find a maltese cross in the cargo door locking mechanism of airbusses, where it seperates latching and locking function of the handle.
A maltese cros is a gear wich converts continious rotation of the input shaft to a stepwise rotation of the output shaft. It´s best known use is for motion picture projectors, where the film has to be moved in steps.
German report (with pictures)
Here you see a picture of a malteser cross used in a
Valve train