Method and apparatus for monitoring the locations of perforations in webs of wrapping material for filter cigarettes or the like

摘要

Rows of perforations which are produced in a plant for the making of webs of tipping paper for use in filter tipping machines are monitored by pneumatic or photoelectronic devices to ascertain the distance between such rows and the nearest marginal portions of the web while the web is transported toward the paster in a filter tipping machine. If the distance between the perforations and the marginal portion deviates from the desired distance, if the perforations are absent and/or if the combined cross-sectional area of perforations per unit length of the web is unsatisfactory, the monitoring system generates signals which are used to warn the attendants so that the attendants can replace the defective web with a satisfactory web and/or to effect segregation of filter cigarettes embodying defective portions of the web.