GB1576004A

GB1576004A - Cigarette end testing

Info

Publication number: GB1576004A
Application number: GB4566576A
Authority: GB
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1976-11-03
Filing date: 1976-11-03
Publication date: 1980-10-01

Description

(54) IMPROVEMENTS IN CIGARETTE END TESTING (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 testing the ends of cigarettes in order to detect soft ends. In the case of a filter-tipped cigarette it is in fact useful to be able to test both ends: the tobacco end is tested in order - to detect cigarettes having ends which are inadequately filled with tobacco, while a- test on the filter end is useful to detect - cigarettes with missing filters.

Cigarettes with soft tobacco ends or missing filters should preferably be automati cally ejected.

Earlier proposals in connection with cigarette end testing are described in our British patent- specification No. 1,335,662.

According to the present invention,- a.

testing device for testing the ends of cigarettes, particularly. to detect any tobacco ends which are inadequately filled with tobacco, comprises means for directing light through the wrapper of the cigarette near the end, and a light detector for receiving light from the end face of the cigarette so that the light detector is illuminated to a degree which depends upon the quantity of tobacco in the end.

Preferably a number of light sources are used which are equi-spaced around the end of the cigarette.

One- embodiment of the invention will.

now be described. by way of example with .

reference to.. the accompanying drawings, in which: Figure 1 is a fragmentary sectional view, on the. 1-ine- I-I n Figure 2,. of a testing de-vice embo.dying ..fhe. main. form of this invention; Figure 2 is a sectioned fragmentary side- view - of ,the,testing device - of Figure 1, showing the testing of one end of a cigarette; Figure 3 is a view similar to Figure 2, but showing the testing of the other end of the cigarette.

As shown particularly in Figure 1, the testing device includes a fluted drum 30 which is arranged to carry successive cigarettes 31 sideways through a test station.

At the test station, the tobacco ends of the cigarettes pass between two pairs of light sources 32 (Figures 1 and 2) which direct four beams of light 32a substantially radially towards the end portion of the cigarette being tested. Each beam of light 32a may, for example, diverge by an angle of about 20 from a point source.

Also at the testing station there is a photo-cell or other light detector 33 carried at one end of a housing 34 which. is mounted in a position such that the end face of the cigarette rubs lightly against the end face of the housing 34. A bundle 35 of light-transmitting fibres is secured within the housing and has an end face which is flush with the right-hand end of the housing so as to lie against the end of each cigarette during testing. A lens 36 in the housing causes the parallel beam of light which is transmitted by the bundle 35 to converge on to the light detector 33.

It will be noted that the light sources 32 are carried by arcuate members 37 and 38 respectively, which are in turn carried by the housing 34. The arrangement is such that the cigarettes pass between the inner and outer pairs of light sources . with as little clearance as is practical, so that the light sources 32 can be as close as possible to the circumference of each cigarette during testing.

When each cigarette reaches the test station; a light beam off short duration is.

emitted by each of the light sources 32, and at the same time the test signal is. ole tained - from the- light detector 33. This test signal will be of - a magnitude depends. dent upon the quantity of tobacco in the end portion of the corresponding cigarette.

If the end portion of the cigarette is inadequately filled then the degree of illumination which is detected by the detector 33 will be greater than in the case of a properly formed cigarette. Cigarettes which are found in this way to have an inadequately filled tobacco end portion may be ejected downstream of the test station in any conventional way, for example by being blown axially or radially off the drum 30. A memory system may be used as described with reference to Figure 3 of our co-pending application No. 49267/75 (Serial No. 1,576,003).

Each of the light sources 32 receives its power from a power unit 39. The light sources may, for example, be infra-red light-emitting diodes. Such diodes can be powered with a high current for a very short duration, for example about 10 micro-seconds, thus providing a high-intensity light beam for a duration which is so short that the movement of the cigarettes relative to the light beams is insignificant. The cigarettes may, for example, move past the light detector at the rate of 4,000 to 5,000 per minute.

Figure 2 shows the testing of the tobacco end portions of the cigarettes. It may also be desirable to test the filter ends to detect any cigarettes with missing filters.

A cigarette with a missing filter may have a hollow tube of tipping paper which is intended to secure a filter portion to the end of the tobacco portion, though it occasionally happens that the filter portion is missing.

As shown in Figure 3, a tubular housing 40 is mounted in a position such that it is coaxial with the cigarette under test and has its open left-hand end close to the end of the cigarette. For detecting missing filters a simpler arrangement may be used than in Figure 2. This arrangement includes a single light source 41 which directs a beam of light axially towards the end of the filter portion 31a of the cigarette from one side of a dividing wall 42 in the housing 40. Light reflected back by the cigarette is detected by a light detector 43.The intensity of light reflected back to the detector 43 depends upon whether or not there is a filter portion; filter portions normally have a white end surface which reflects light relatively well, whereas in the absence of a filter portion the light beam from the source 41 impinges only on the end of the tobacco filling in the cigarette, so that less light is reflected back to the detector 43.

As shown in Figure 3, the housing 40 also includes a bundle of light-transmitting fibres 44. This bundle may, however, be omitted, in which case the dividing wall 42 would be extended further towards the cigarette end.

The light source 41 is pulsed simultaneously with the light sources 32 by the power unit 39, for examples as described with reference to the testing device shown in Figures 1 to 3 of our co-pending application No. 49267/75 (Serial No. 1,576,003).

It is important to note that the radial beams of light emitted by the light sources 32 lie in a plane which is inwardly spaced slightly, but not too far, from the end face of the cigarette. For example, the plane of the light beams may lie 2 to 3 mm from the end face of the cigarette. If the cigarette is adequately filled with tobacco, then, as a result of scatter and absorbsion of the light by the tobacco, relatively little light reaches the light detector 33. However, if the end of the cigarette is inadequately filled with tobacco, then more light will reach the light detector, which will produce an output signal indicating that the cigarette is faulty and is to be ejected.

It is possible, in principle, to use a single light source 32 instead of four as shown.

However, it is better to use a number of light sources to producing beams of light from various directions (preferably evenly spaced around the cigarette) to help to ensure that a cigarette end which has a significant quantity of tobacco missing on one side can be detected.

It is important to note that the bore in the housing 34 through which light is transmitted to the detector 33 is substantially the same diameter as the cigarette, so that light from substantially the whole end face of the cigarette is received by the detector In order to prevent any light from any of the light sources 32 passing directly to the detector (e.g. by reflection off the cigarette wrapper) the bore in the housing 34 should not be larger than the cigarette diameter.

The lens 36 may be omitted if a largerdiameter light detector 33 is used.

In place of the bundle of fibres 35, there may be a rod of glass or other translucent material which is preferably machined flush with the end of the housing 34 contacting the cigarettes.

WHAT WE CLAIM IS:- 1. A testing device for testing the tobacco ends of cigarettes to detect cigarettes of which the tobacco ends are inadequately filled with tobacco, comprising means for directing light through the wrapper of the cigarette near the end and a light detector for receiving light from the end face of the cigarette so that the light detect tor is illuminated to a degree which depends upon the quantity of tobacco in the end.

2. A testing device according to claim

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. end portion of the corresponding cigarette. If the end portion of the cigarette is inadequately filled then the degree of illumination which is detected by the detector 33 will be greater than in the case of a properly formed cigarette. Cigarettes which are found in this way to have an inadequately filled tobacco end portion may be ejected downstream of the test station in any conventional way, for example by being blown axially or radially off the drum 30. A memory system may be used as described with reference to Figure 3 of our co-pending application No. 49267/75 (Serial No. 1,576,003). Each of the light sources 32 receives its power from a power unit 39. The light sources may, for example, be infra-red light-emitting diodes. Such diodes can be powered with a high current for a very short duration, for example about 10 micro-seconds, thus providing a high-intensity light beam for a duration which is so short that the movement of the cigarettes relative to the light beams is insignificant. The cigarettes may, for example, move past the light detector at the rate of 4,000 to 5,000 per minute. Figure 2 shows the testing of the tobacco end portions of the cigarettes. It may also be desirable to test the filter ends to detect any cigarettes with missing filters. A cigarette with a missing filter may have a hollow tube of tipping paper which is intended to secure a filter portion to the end of the tobacco portion, though it occasionally happens that the filter portion is missing. As shown in Figure 3, a tubular housing 40 is mounted in a position such that it is coaxial with the cigarette under test and has its open left-hand end close to the end of the cigarette. For detecting missing filters a simpler arrangement may be used than in Figure 2. This arrangement includes a single light source 41 which directs a beam of light axially towards the end of the filter portion 31a of the cigarette from one side of a dividing wall 42 in the housing 40. Light reflected back by the cigarette is detected by a light detector 43.The intensity of light reflected back to the detector 43 depends upon whether or not there is a filter portion; filter portions normally have a white end surface which reflects light relatively well, whereas in the absence of a filter portion the light beam from the source 41 impinges only on the end of the tobacco filling in the cigarette, so that less light is reflected back to the detector 43. As shown in Figure 3, the housing 40 also includes a bundle of light-transmitting fibres 44. This bundle may, however, be omitted, in which case the dividing wall 42 would be extended further towards the cigarette end. The light source 41 is pulsed simultaneously with the light sources 32 by the power unit 39, for examples as described with reference to the testing device shown in Figures 1 to 3 of our co-pending application No. 49267/75 (Serial No. 1,576,003). It is important to note that the radial beams of light emitted by the light sources 32 lie in a plane which is inwardly spaced slightly, but not too far, from the end face of the cigarette. For example, the plane of the light beams may lie 2 to 3 mm from the end face of the cigarette. If the cigarette is adequately filled with tobacco, then, as a result of scatter and absorbsion of the light by the tobacco, relatively little light reaches the light detector 33. However, if the end of the cigarette is inadequately filled with tobacco, then more light will reach the light detector, which will produce an output signal indicating that the cigarette is faulty and is to be ejected. It is possible, in principle, to use a single light source 32 instead of four as shown. However, it is better to use a number of light sources to producing beams of light from various directions (preferably evenly spaced around the cigarette) to help to ensure that a cigarette end which has a significant quantity of tobacco missing on one side can be detected. It is important to note that the bore in the housing 34 through which light is transmitted to the detector 33 is substantially the same diameter as the cigarette, so that light from substantially the whole end face of the cigarette is received by the detector In order to prevent any light from any of the light sources 32 passing directly to the detector (e.g. by reflection off the cigarette wrapper) the bore in the housing 34 should not be larger than the cigarette diameter. The lens 36 may be omitted if a largerdiameter light detector 33 is used. In place of the bundle of fibres 35, there may be a rod of glass or other translucent material which is preferably machined flush with the end of the housing 34 contacting the cigarettes. WHAT WE CLAIM IS:-

1. A testing device for testing the tobacco ends of cigarettes to detect cigarettes of which the tobacco ends are inadequately filled with tobacco, comprising means for directing light through the wrapper of the cigarette near the end and a light detector for receiving light from the end face of the cigarette so that the light detect tor is illuminated to a degree which depends upon the quantity of tobacco in the end.

2. A testing device according to claim

1, comprising a light source arranged to direct a beam of light onto the side of each cigarette near the end, the light detector being substantially axially in alignment with the end of the cigarette.

3. A testing device according to claim 2 in which there are at least two light sources which are arranged to direct beams of light simultaneously onto the side of the cigarette wrapper, near the tobacco end of the cigarette, from opposite sides of the cigarette.

4. A testing device according to claim 2 or claim 3 in which the light is transmitted to the light detector from the end of each cigarette in turn by a bundle of lighttransmitting fibres.

5. A testing device according to claim 4 in which the bundle of light-transmitting fibres has a diameter substantially equal to that of the cigarettes.

6. A testing device according to any preceding claim in which the light source or sources receive short-duration pulses of current timed to coincide with the arrival of successive cigarettes at the test station.

7. A testing device according to claim 1 and substantially as described with reference to the accompanying drawings.