Filter plug feeding apparatus for a filter cigarette manufacturing machine

A filter plug feeding apparatus comprises a pair of hoppers in which charcoal and plain filter rods are stored, a pair of hopper drums for delivering charcoal and plain filter rods from the hoppers, respectively, the hoppers being able to discharge the filter rods in a manner such that the axial centers of the filter rods are situated individually on feeding lines for their corresponding hopper drums and the delivered filter rods being cut into a pair of filter half rods on the hopper drums, a separation drum for separate a pair of charcoal half rods received from one hopper drum, an assembly drum for receive the pair of charcoal half rods the from the separation drum and a pair of plain half rods from the other hopper drum, and rotary knives detachably attached to the assembly drum and capable of cutting each of the charcoal half rod into a pair of charcoal plugs.