| 摘要 |
<p>In cigarette conveying apparatus cigarettes are conveyed along a path so that they are intercepted in sequence by beams directed at different portions of the path to produce a complete circumferential row of perforations on each cigarette after it has traversed the path. An incident laser beam (14) is time-shared to produce pulses for making perforations by mutually inclined rotatable discs (20, 28). A temperature sensor (150) is provided to detect build-up of contaminants on a lens or mirror (146) for a laser beam (32B). A stream of air containing small quantities of water is supplied by tubes (380,388) terminating in the region in which the cigarettes are perforated so as to assist removal of contaminants resulting from laser perforation.</p> |
