Method and apparatus for ventilated cigarette manufacture

Claim 3

A method according to claim 1 in which said testing device is a porosity measuring device and in which the porosity of the web is measured after the formation of the first perforations but before the formation of the additional perforations.

Claim 4

A method according to claim 2 in which the accurately controllable perforator is also controlled in response to the speed of the tipping paper.

Claim 5

A method according to claim 1, wherein said testing device is a cigarette dilution testing device.

Claim 6

Apparatus for making ventilated cigarettes, including first perforator means which is not readily susceptible to accurate control of the degree of perforation effected thereby for forming perforations at least in the tipping paper by which cigarettes are joined to filter portions so as to produce an approximate level of dilution slightly below a desired level; a second accurately controllable perforator means for forming additional perforations in the tipping paper prior to assembly of the filter cigarettes; and control means arranged to control said second perforator means in response to a measuring signal from a testing device which indicates the affect of the first-mentioned perforations on the ventilation provided by said tipping paper.

Claim 7

Apparatus for making ventilated cigarettes, including first perforator means which is not readily susceptible to accurate control of the degree of perforation effected thereby for forming perforations at least in the tipping paper by which cigarettes are joined to filter portions so as to produce an approximate level of dilution slightly below a desired level; a second accurately controllable perforator means for forming additional perforations in the tipping paper prior to assembly of the filter cigarettes; and control means arranged to control said second perforator means in response to a measuring signal from a testing device which indicates the affect of the first-mentioned perforations on the ventilation provided by said tipping paper.

Claim 8

Apparatus according to claim 5 in which the first perforator means is a mechanical perforator.

Claim 9

Apparatus according to claim 6 in which the first perforator means comprises pins.

Claim 10

Apparatus according to any one of claims 5 to 7 in which the second perforator means is a laser perforator.

Claim 11

Apparatus according to claim 8 in which the laser perforator is arranged to emit pulses of laser radiation.

Claim 12

Apparatus according to claim 9 in which the frequency of the pulses is controlled in response to the measuring signal from a porosity measuring device which measures the porosity of said tipping paper.

Claim 13

An apparatus according to claim 9, in which the frequency of the pulses is controlled in response to the measuring signal from a cigarette dilution testing device.

Claim 14

Apparatus for producing ventilated cigarettes, comprising means for transporting a web of cigarette tipping paper to a cigarette assembly machine; first perforator means which is not readily susceptible to accurate control of the degree of perforation effected thereby for forming perforations at least in a first region of the web to produce an approximate level of ventilation slightly below a desired level; a second controllable perforator means for perforating a second region of the web to complete the ventilation effect; means for measuring the porosity of the web after it has been perforated at least by the first perforator means; for measuring the dilution of cigarettes assembled by the assembly machine which include sections of the perforated web; and control means for controlling the second perforator means in response to the measured porosity and in response to the measured dilution.

Claim 15

Apparatus for producing ventilated cigarettes, comprising means for transporting a web of cigarette tipping paper to a cigarette assembly machine; first perforator means which is not readily susceptible to accurate control of the degree of perforation effected thereby for forming perforations at least in a first region of the web to produce an approximate level of ventilation slightly below a desired level; a second controllable perforator means for perforating a second region of the web to complete the ventilation effect; means for measuring the porosity of the web after it has been perforated at least by the first perforator means; for measuring the dilution of cigarettes assembled by the assembly machine which include sections of the perforated web; and control means for controlling the second perforator means in response to the measured porosity and in response to the measured dilution.

Claim 16

Apparatus according to claim 9 in which the control means is arranged to adjust the second perforator means rapidly in response to changes in the web porosity and is arranged to adjust the second means in response to changes in cigarette dilution in a progressive manner.

Claim 19

A method according to claim 14, wherein said first perforator is caused to perforate the tipping paper of each cigarette before the cigarette is assembled.

Claim 20

A method according to claim 15, wherein said testing step comprises testing the porosity of the tipping paper after it has been perforated by said first perforator.

Claim 21

A method according to claim 14, wherein said first perforator is caused to perforate each cigarette after it has been assembled.