GB1564314A

GB1564314A - Cigarettes

Info

Publication number: GB1564314A
Application number: GB1016579A
Authority: GB
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1977-03-10
Filing date: 1977-03-10
Publication date: 1980-04-10

Description

(54) IMPROVEMENTS RELATING TO CIGARETTES (71) We, MOLINS LIMITED, a British Company, of 2, Evelyn Street, Deptford, London, SE8 5DH., do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention is concerned with what may be termed "ventilated cigarettes", that is to say cigarettes (especially filter-tipped cigarettes) provided with a deliberate leakage path through the wrapper near the mouth end of the cigarette. Air from the atmosphere flows in through the leakage path while the smoker is drawing on the cigarette. This air flow dilutes the smoke which is drawn in by the smoker.

In this context the term "tobacco" is intended to include all smokable materials which may be used in cigarettes, for example artificial tobacco or mixtures of natural and artificial tobacco.

More specifically, this invention is concerned with the testing of ventilated cigarettes which include a circumferentially extending row of perforations in the wrapper of the cigarette near the mouth end of the cigarette.

According to this invention, apparatus for testing such ventilated cigarettes comprises means defining a perfortating testing space around the perforations of each cigarette in turn during a first test period, means for producing a difference in pressure between the annual test space and the interior of the cigarette during the first test period, means operative during a second test period for producing a difference in pressure between the interior of the cigarette and a second space around the cigarette which is separate from the perforation testing space, detector means for detecting the air flow through the wrapper of the cigarette during the first and second test periods, and means for producing a fault signal if the air flow during the first test period is below a first limit and if the air flow during the second test period is above a second limit.

An example of a cigarette testing apparatus according to this invention will now be described with reference to the accompanying drawings. In these draw ings:- Figure 1 is a partly sectioned side elevation of one form of ventilated cigarette; Figure 2 is a schematic view showing apparatus for making the cigarettes shown in Figure 1; Figure 3 shows a basically conventional form of cigarette testing apparatus for testing the cigarette shown in Figure 1; and, Figure 4 shows a cigarette testing apparatus according to this invention.

The cigarette shown in Figure 1 comprises a filter rod portion 10 and a tobaccofilled rod 12 joined together by a uniting band 14 of paper. The filter rod section includes filter material 10A and a wrapper 10B which is formed with a circumferentially extending row of perforations lOC.

The tobacco-filled section includes a wrapper 12A.

It should be noted that the perforations 1 0C are intermediate the ends of the filter rod section 10 and that the uniting band is wide enough to surround the abutting ends of the rods but does not cover the perforations lOC.

As an alternative, the wrapper lOB of the filter rod section 10 could be uniformly porous so as to provide the ventilation path for air from the atmosphere to flow into the filter.

Figure 2 shows schematically how the cigarette of Figure 1 may be made. A stream 16 of filter material, for example in the form of a cellulose acetate tow, is fed through a funnel 18 and onto a continuous wrapper web 20. The web 20 and the filter material then pass into a rod-forming de vice 22 in which the web is wrapped and secured around the filter material to form a continuous filter rod 24. This rod 24 is cut at regular intervals by cutting mechanism 26 to produce a succession of filter rods 28. These rods are then deflected sideways and are delivered to a filter-attachment machine 30.

Each of the filter rods 28 comprises, for example, four or six individual filter rod portions. In the filter attachment machine 30, the rods are cut into four or six sections, as the case may be, and each of these portions is joined to a tobacco filled rod.

A stream of filter-tipped cigarettes 32 such as the cigarette shown in Figure 1 is delivered by the filter-attachment machine 30.

The filter attachment machine may, for example, be as described in our British patent application No. 21365/75 Serial No.

1531424 (and corresponding German Offenlegungschrift No. 2622449) to which reference is directed in its entirety.

The wrapper web 20 is drawn from a reel 34 and passes around a guide pulley 36 on its way to the rod-forming device 22.

Adjacent to the pulley 36 there is a wheel 38 formed with a number of circumferentially-spaced axially-extending rows of pins.

These pins perforate or semi-perforate the web 20 at regular intervals. The cutting mechanism 26 is timed relative to the wheel 38 so as to cut the continuous rod at appropriate positions in relation to the rows of perforations.

As an alternative to the perforating arrangement, there may be a sparking device for perforating the web 20 either continuously or at regular intervals.

Figure 3 is a section through a test drum by which the cigarettes can be tested to ensure that there is no excessive leak in the wrapper (aside from the deliberate leakage perforations) such as can result from an imperfect longitudinal seam in the wrapper of the tobacco rod, a hole in the tobacco wrapper or imperfect adhesion of the uniting band to the tobacco or filter rod.

The cigarette testing apparatus shown in Figure 3 operates basically in accordance with the invention described in our British patent specification No. 1,195,682. The cigarettes 40 are carried during testing by a drum 42. Extending around part of the drum there is a fixed housing 44 which defines, with the drum, a suction chamber 46 extending around each cigarette during testing; the clamber 46 communicates with a source of suction 45 through an inlet 44A.

Each cigarette at its filter end rests in a semi-cylindrical flute in the drum formed by two portions 42A and 42B separated by an annular groove 42C. A seal around the cigarette is completed by a movable end cap 48 which has similar flute sections 48A and 48B separated by an annular groove 48C which lines up with the groove 42C in the drum to form an annular space around the cigarette. This space is vented to atmosphere through a passage 48D, thus completely isolating the suction space 46 from a space 50 adjacent to the end of the cigarette.

During the testing of each cigarette a suction pressure is created in the space 50 and indicates the degree of leakage of air through the wrapper of the cigarette in the region contained within the suction space 46. A passage 52 in the drum leads to an end face of the drum against which a fixed pad 52 is in sealing engagement. A passage 54A in the pad communicates with an arcuate slot 54B in the face of the pad which communicates with each passage 52 in turn during testing. Passage 54 and is connected to a pressure detector (not shown), for example a diaphragm transducer, from which an electrical signal can be obtained which is indicative of the leakage through the cigarette.

The flute sections 42A and 48A respectively in the drum and cap surround a circumferentially extending row of ventilation perforations 40A in the cigarette.

These flute sections are a close fit around the cigarette, so that substantially no air fllows through the perforations 40A during testing.

At the other end of the cigarette a movable cap 56 similarly defines a seal around the cigarette with an annular space 58 which is vented to atmosphere through a passage 56A.

The caps 48 and 56 seal off the ends of the suction space 46 around the cigarette.

The caps may be pivotally mounted, as described in British patent specification No. 1,195,682 or may be linearly movable as described in our British patent application No. 4464/74 Serial No. 1472068 (and German Offenlegungschrift 2,503,857) to which reference is directed in its entirety.

There is preferably a leakage path to atmosphere from the end space 50. This may be provided by a passage extending to atmosphere from the passage 52, or may be provided by forming the flute portions 42B and 48B slightly larger in diameter than the cigarette so as to provide limited communication between the end space 50 and the atmospheric space 48C.

Figure 4 shows a testing apparatus according to this invention. The apparatus shown comprises a modification of part of the testing apparatus shown in Figure 3; similar or equivalent parts have the same reference numerals as in Figure 3.

In the apparatus shown in Figure 4, instead of the perforations 40A in the filter wrapper being closed during testing by close-fitting flute sections of the drum and cap, the drum and cap together form a perforation testing space 60 surrounding the perforations 40A; the perforations are in this case closer to the mouth end (the right-hand end) of the cigarette. On opposite sides of the annular space 60 the drum 42 and cap 48 are formed with cooperating grooves forming two annular spaces 62 and 64 which are vented to atmosphere by openings 62A and 64A respectively.

During a first test period, a source of suction 66 (which may be common with the source 45) is connected to the perforation test space 60 via a passage 68 and a second fixed pad 70. This pad 70 has a short arcuate slot 70A which connects the passage 68 to the suction source 66 only for part of the time during which the arcuate slot 54B (which is longer) connects the end space 50 for each cigarette to a pressure detector 72.Thus for part of the total testing cycle for each cigarette the suction pressure detected by the detector 72 is dependent upon air flow through substantially the whole wrapper of the cigarette, including the perforations 40A, this being the "first test period"; during the second test period the passage 68 is closed by the pad 69 so as to be isolated both from the atmosphere and from the suction source, and during this second period the detector 72 will sense a suction pressure which is indicative of the leakage flow through the part of the wrapper of the cigarette which lies within the suction space 46.

The detector 72 may transmit an electrical output signal to an electronic comparator circuit 74 (of a known kind) which produces a fault signal if the suction pressure received by the detector 72 during the first test period is too low (indicating inadequate ventilation of the cigarette) or if the suction pressure received during the second test period is too great. The first and second test periods for each cigarette may occur in either order.

Reference is directed to patent application No. 10596/76 (Serial No. 1564313).

WHAT WE CLAIM IS: 1. Apparatus for testing ventilated cigarettes which include a circumferentially extending row of perforations in the wrapper of the cigarette near the mouth end of the cigarette, comprising means defining a perforation testing space around the perforations of each cigarette in turn during a first test period, means for producing a difference in pressure between the annular test space and the interior of the cigarette during the first test period, means operative during a second test period for producing a difference in pressure between the interior of the cigarette and a second space around the cigarette which is separate from the perforation testing space, detector means for detecting the air flow through the wrapper of the cigarette during the first and second test periods, and means for producing a fault signal if the air flow during the first test period is below a first limit and if the air flow during the second test period is above a second limit.

2. Apparatus according to claim 1 in which the annular test space is formed around the perforations of each cigarette during both test periods but is isolated during the second test period so that the air flow during the second test period is indicative of leakage through a part of the cigarette which does not include the row of perforations.

3. Apparatus according to claim 2 in which the second space around the cigarette is defined by a housing and is arranged to communicate with a source of suction pressure during the second test period, the perforating testing space being arranged to communicate with a source of suction pressure during the first test period.

4. Apparatus according to claim 3 in which the detector means comprises a pressure detector which communicates with a space at the mouth end of each cigarette in turn during both test periods.

5. Apparatus according to claim 1 and substantially as described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the testing apparatus shown in Figure 3; similar or equivalent parts have the same reference numerals as in Figure 3. In the apparatus shown in Figure 4, instead of the perforations 40A in the filter wrapper being closed during testing by close-fitting flute sections of the drum and cap, the drum and cap together form a perforation testing space 60 surrounding the perforations 40A; the perforations are in this case closer to the mouth end (the right-hand end) of the cigarette. On opposite sides of the annular space 60 the drum 42 and cap 48 are formed with cooperating grooves forming two annular spaces 62 and 64 which are vented to atmosphere by openings 62A and 64A respectively. During a first test period, a source of suction 66 (which may be common with the source 45) is connected to the perforation test space 60 via a passage 68 and a second fixed pad 70. This pad 70 has a short arcuate slot 70A which connects the passage 68 to the suction source 66 only for part of the time during which the arcuate slot 54B (which is longer) connects the end space 50 for each cigarette to a pressure detector 72.Thus for part of the total testing cycle for each cigarette the suction pressure detected by the detector 72 is dependent upon air flow through substantially the whole wrapper of the cigarette, including the perforations 40A, this being the "first test period"; during the second test period the passage 68 is closed by the pad 69 so as to be isolated both from the atmosphere and from the suction source, and during this second period the detector 72 will sense a suction pressure which is indicative of the leakage flow through the part of the wrapper of the cigarette which lies within the suction space 46. The detector 72 may transmit an electrical output signal to an electronic comparator circuit 74 (of a known kind) which produces a fault signal if the suction pressure received by the detector 72 during the first test period is too low (indicating inadequate ventilation of the cigarette) or if the suction pressure received during the second test period is too great. The first and second test periods for each cigarette may occur in either order. Reference is directed to patent application No. 10596/76 (Serial No. 1564313). WHAT WE CLAIM IS:

1. Apparatus for testing ventilated cigarettes which include a circumferentially extending row of perforations in the wrapper of the cigarette near the mouth end of the cigarette, comprising means defining a perforation testing space around the perforations of each cigarette in turn during a first test period, means for producing a difference in pressure between the annular test space and the interior of the cigarette during the first test period, means operative during a second test period for producing a difference in pressure between the interior of the cigarette and a second space around the cigarette which is separate from the perforation testing space, detector means for detecting the air flow through the wrapper of the cigarette during the first and second test periods, and means for producing a fault signal if the air flow during the first test period is below a first limit and if the air flow during the second test period is above a second limit.