Method and apparatus for monitoring and controlling the production of composite filter mouthpieces for cigarettes or the like

DETAILED DESCRIPTION What is claimed is: 1.
A method of producing and controlling the production of composite mouthpieces for use in the manufacture of filter cigarettes or the like, comprising the steps of assembling a continuous filter rod consisting of several types of alternating dissimilar filler rod sections which absorb radiation to a different degree; conveying the filler rod lengthwise along a predetermined path; draping the filler rod into a web of wrapping material to form a filter rod wherein the web constitutes a tube surrounding the filler rod; directing a beam of radiation against one of said rods in a first portion of said path whereby different types of sections absorb radiation to a different degree; monitoring the characteristics of said beam subsequent to impingement upon said one rod and generating first signals in response to changes of such characteristics; generating second signals in response to movement of successive unit lengths of sections of at least one type along said path, each unit length being a small fraction of the overall length of a section of satisfactory length; and counting the number of second signals which are generated subsequent to the generation of a first signal.
2.
A method as defined in claim 1, wherein said last mentioned step comprises counting the number of second signals during intervals between the generation of successive first signals.
3.
A method as defined in claim 2, further comprising the step of generating a third signal when the number of second signals during said intervals is less than a predetermined number.
4.
A method as defined in claim 2, further comprising the step of generating an additional signal when the number of second signals during said intervals exceeds a preselected number.
5.
A method as defined in claim 2, further comprising the step of generating a further signal when the total number of second signals during said intervals is outside of a predetermined range.
6.
A method as defined in claim 5, further comprising the steps of subdividing said filter rod into filter mouthpieces, conveying said mouthpieces along a second path, and expelling from said second path each mouthpiece containing a section whose exposure to radiation resulted in the generation of a further signal