Interlock servo

An interlock servo was a component of airlocks.

In 2369, the Cardassian forces who abandoned Terok Nor before it became Deep Space 9 stripped the interlock servos from at least one of the airlocks. When Benjamin Sisko and Jake Sisko came aboard the station, Miles O'Brien had to manually override the airlock. 

When several individuals were trapped inside an airlock, Chief O'Brien tried to activate the interlock servos to open the airlock itself.