The invention relates to a method of and to an apparatus for perforating
the tubular wrappers of plain or filter cigarettes and other rod-shaped
articles of the tobacco processing industry. The articles are advanced
sideways at the periphery of a rotary drum-shaped carrier which
cooperates with a device serving to roll them about their longitudinal
axes while the wrappers are being perforated by one or more pulsating
beams issuing from one or more lasers and passing through a stationary
cylinder lens on their way to the facets of a rotating cylindrical mirror
which directs the beam(s) across the axis of the carrier and pivots the
beam(s) about such axis on its or their way radially outwardly of the
carrier toward a first set of stationary deflecting mirrors. These
mirrors deflect the beam(s) in at least substantial parallelism with the
axis of the carrier at locations radially outwardly of the latter's
periphery toward a second set of deflecting mirrors which, in turn,
direct the beam(s) substantially radially toward the axis of the carrier
and against spherical lenses which focus the beam(s) upon the wrappers of
the articles.