Spent cartridges router means in a configuration of a four bars or four bar linkage mechanism for routing spent cartridges ejected from a chain fed automatic weapon towards means for gathering cartridges that is installable as an ad-on and independent (stand alone) mechanism on a weapon station of the type that comprises a base assembly that is rotatable for traverse motion, a cradle assembly that is located on the base assembly and linked with it in axial (pivotally) manner and chain fed automatic weapon that is affixable on the cradle assembly in a manner that it will be rotatable for elevation and lowering around the cradle's axis.