GB1576003A

GB1576003A - Cigarette and testing

Info

Publication number: GB1576003A
Application number: GB4926775A
Authority: GB
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1975-12-01
Filing date: 1975-12-01
Publication date: 1980-10-01
Also published as: SE7613414L

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 automatically 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 ends which are inadequately filled with tobacco or which lack a filter plug, comprises means for applying a predetermined pressure to the cigarette wrapper near the end of the cigarette which is being tested, so as to deform the end to a degree which depends upon the compressability of the end, a light source arranged to direct a beam of light onto the wrapper at or near the position where the pressure is applied, and light detecting means which is so positioned relative to the light source and the cigarette under test, that the beam of light is reflected from the cigarette directly towards the detecting means only in the case of a cigarette end which is not significantly deformed by the applied pressure.

Preferably the pressure is applied bv means of a nozzle arranged to direct.a jet of air onto the wrapper of each cigarette to be tested, near the end which is being tested, the beam of light being directed onto the side of the cigarette at or near the position where the air jet hits the cigarette, so that the beam of light is reflected from the surface of the cigarette at an angle which depends upon the amount of inward deformation of the wrapper by the air jet. The light detector is preferably mounted in a position such that it receives a significant proportion of the light reflected from the wrapper of each cigarette with an adequately firm end, and received less light or no light from the wrapper of a less firm cigarette.There is preferably a first optical system by which the light beam from the source is focused on a small area of the surface of the cigarette, the light detector being associated with an optical system focused on the same area.

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 side view showing a filtertipped cigarette in the testing position of a testing device; Figure 2 is an enlarged fragmentary section on the line II-II in Figure 1; and Figure 3 is an electronic circuit diagram for the testing device shown in Figures 1 and 2.

Figure 1 shows a filter-tipped cigarette 10 comprising a tobacco portion 10A and a filter 10B. The filter is joined to the tobacco portion by a piece of "tipping" paper which is wrapped around the filter and overlaps the adjacent end of the tobacco portion. During the assembly of filters with tobacco portions, in the event of the filter itself being missing, the tipping paper forms a hollow tube.extending from one end of the tobacco portion; such cigarettes are unacceptable and are required to be ejected.

Figure 1 shows two testing devices 11 and 13 adjacent to opposite ends of the cigarette 10. The device 11 detects missing filters, and the device. 13. detects cigarettes with soft tobacco ends. Between the devices 11 and 13 there is a device 12 which is used to detect the presence of a cigarette, and stops the system from registering a fault when there is no cigarette present, for example while the cigarette making machine is being started.

Figure 2 is a section through the testing device 11. The device 13 is similar, while the device 12 is similar except that it does not include an air nozzle.

As shown in Figure 2, the device 11 comprises a body 14 formed with a passage 15 which has a convergent downstream end portion lSA serving as a nozzle through which a jet of air is directed radially towards the cigarette 10. An adjustable restrictor 16 (shown diagrammatically) in the passageway 15 enables the strength of the air jet to be adjusted to suit different circumstances; for example, different cigarettes may ideally require air jets of different strength, and the missing filter detector 13 might require an air jet of different strength from the tobacco end tester.

On one side of the passage 15 there is a passage 17 at one end of which a light source in the form of a light-emitting diode 18 is mounted. The diode 18 may, for example, be that identified as the Motorola (RTM) MLED 610, which has a diameter of 15 mm and is 2 mm long. The beam of light. passing through the passage 17 is focused on the cigarette by means of an optical system comprising a lens 19 so as to produce a light spot on the cigarette approximately 1 mm x 1-5 mm in size.

The. axis of the beam and lens is inclined to the air jet by an angle 0 which may be 45" as shown.

On the other side of the air passage 15 there is a passage 20 which is inclined to the passage 15 by the same angle 0. At the lower end of the passage 20 there is an optical system comprising a lens 21 which is associated with a light detector in the form of a photo-transistor 22 having the same dimensions as the diode 18. The transistor 22 may be that identified as the Motorola (RTM) MRD 603. The lens 21 is focused on the spot on the surface of the cigarette (when undistorted) which is illuminated by the beam of -light from the diode 18.

The axes of the passages 15, 17 and 20 (and. accordingly also the axes of the lenses 19 and 21) all lie in a common plane normal to the axis of the cigarette 10 at the test station.

Figure 2 also shows that successive cigarettes 10 are carried sideways past the testing devices on a fluted drum 23. The diode 18 is supplied with high-current pulses which are timed to coincide with the arrival of each cigarette in turn at the testing station, i.e. directly below the air nozzle. In other words, the diode 18 emits a beam of light only for a brief interval of time while each cigarette is directly aligned with the air jet. The same applies to the light-emitting diodes of the devices 12 and 13.

The air supplied to the nozzle lSA may, for example, be at about 2 pounds per square inch. The air jet is preferably adjusted by means of the restrictor 16 so as to be not strong enough to deform significantly the wrapper of a sufficiently firm cigarette, but to deform inwards a soft tobacco end (or a tipping paper tube without a filter) to an extent sufficient to reduce significantly the amount of light which then reaches the transistor 22. Figure 2 shows, by way of example, how the wrapper or tipping paper of an unsatisfactory cigarette may be inwardly deformed by the air jet.

Light.reflected off the surface of a sound cigarette tends to scatter, but we have found that sufficient light does reach the photo transistor 22 in the case of a satisfactory cigarette. When the surface of the cigarette is inwardly deformed to a significant extent, substantially no reflected light reaches the photo transistor, the light being mostly deflected right out of the plane containing the axes of the two optical systems on account of the inward inclination of the surface of the cigarette from which the light is reflected; as shown by the dotted line JOC in Figure 1.

In this system a fault is signalled by the absence of a photo-electric output. A strobing system may be used, on the basis of a machine-derived strobe pulse, to power the diodes 18 at suitable intervals. In view of the rather low efficiency of optical reflection from a cigarette, it is important to pulse the diodes with a high current, for a short duration, when each cigarette in turn is at the test station.

A circuit diagram of the system is shown in Figure 3. A machine-derived timing pulse from a device 1 triggers a monostrable device 2, generating a pulse of 200 micro-second duration for every cigarette.

From this, a current generator 3 delivers a pulse 1 amp to each diode when the cigarette is in the position shown in Figure 1.

The output of each of the detector devices 11, 12 and 13 is fed bv an amplifier.

All, A12 and A13. Amplifiers All a^ A13 are inverting amplifiers, while .ampli- fier A12 is a non-inverting amplifier.

Gates Gl and G2 receive strobe pulses (i.e.

timed input pulses) from the monostahle device 2 via a 150 micro-second delay device 4 and a 10 micro-second monostable device 5. Gate G1 produces an output for the duration of the strobe pulse if there is an output from the device 12 but not from device 11, that is to say in the case of a missing filter. Similarly gate G2 gives an output pulse for a cigarette with a soft end. From these gate outputs, fault pulses of five milli-second duration are produced by 5 milli-second monostable devices 6 and 7 respectively. These fault pulses may be transmitted to a data logging system.

Either category of fault (i.e. a missing filter or a soft tobacco end) provides the data input of a shaft register memory 8 which is clocked by the trailing edge of the output of the monostable device 2. By means of this memory, faulty cigarettes may be removed, downstream of the test station, by a blast of air (in a known manner) released by a solenoid controlled valve 9B powered at the appropriate moment by a driver 9A which receives enabling pulses from the monostable device 2 as shown.

The rejection device and the testing devices are so positioned with respect to the cigarette path that the same timing pulse can be used by each.

Tests on one example of equipment according to this invention using a 2 pounds per square inch source of compressed air produced the following results. The air jet deflected a typical soft cigarette end by approximately 1 mm to 15 mm at the end of the cigarette wrapper. The same strength of air jet produced a larger deflection at the filter end in the case of a missing filter.

The body 14 of each of the testing devices 11 and 13 may be formed with bleed passages extending from the air passage 15 to near the lenses 19 and 21 to blow air over the outer surfaces of the lenses to keep the lenses clean.

WHAT WE CLAIM IS: - 1. A testing device for testing the ends of cigarettes, particularly to detect ends which are inadequately filled with tobacco or which lack a filter plug, comprising means for applying a predetermined pressure to the cigarette wrapper near the end of the cigarette which is being tested, so as to deform the end to a degree which depends upon the compressibility of the end, a light source arranged to direct a beam of light onto the wrapper at or near the position where the pressure is applied, and light detecting means which is so positioned relative to the light source and the cigarette under test, that the beam of light is reflected from the cigarette directly towards the detecting means only in the case of a cigarette end which is not significantly deformed by the applied pressure.

2. A testing device according to claim 1 in which the means for applying pressure comprises a nozzle arranged to direct a jet of air onto the wrapper of each cigarette to be tested.

3. A testing device according to claim 2 including a first optical system by which the light beam from the source is focused on a small area of the surface of the cigarette, and in which the light detector is associated with an optical system focused on the same area.

4. A testing device according to claim 3 in which the axes of both optical systems lie in a plane normal to the axis of the cigarette under test.

5. A testing device according to claim 4 in which the air jet is directed radially onto the cigarette along a path which bisects the angle between the axes of the two optical systems.

6. A testing device according to any one of claims 3 to 5 in which the light source is a light-emitting diode which is powered by short pulses of current timed to coincide with the arrival of successive cigarettes at the testing station.

7. A testing device 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 duration of the strobe pulse if there is an output from the device 12 but not from device 11, that is to say in the case of a missing filter. Similarly gate G2 gives an output pulse for a cigarette with a soft end. From these gate outputs, fault pulses of five milli-second duration are produced by 5 milli-second monostable devices 6 and 7 respectively. These fault pulses may be transmitted to a data logging system. Either category of fault (i.e. a missing filter or a soft tobacco end) provides the data input of a shaft register memory 8 which is clocked by the trailing edge of the output of the monostable device 2. By means of this memory, faulty cigarettes may be removed, downstream of the test station, by a blast of air (in a known manner) released by a solenoid controlled valve 9B powered at the appropriate moment by a driver 9A which receives enabling pulses from the monostable device 2 as shown. The rejection device and the testing devices are so positioned with respect to the cigarette path that the same timing pulse can be used by each. Tests on one example of equipment according to this invention using a 2 pounds per square inch source of compressed air produced the following results. The air jet deflected a typical soft cigarette end by approximately 1 mm to 15 mm at the end of the cigarette wrapper. The same strength of air jet produced a larger deflection at the filter end in the case of a missing filter. The body 14 of each of the testing devices 11 and 13 may be formed with bleed passages extending from the air passage 15 to near the lenses 19 and 21 to blow air over the outer surfaces of the lenses to keep the lenses clean. WHAT WE CLAIM IS: -

1. A testing device for testing the ends of cigarettes, particularly to detect ends which are inadequately filled with tobacco or which lack a filter plug, comprising means for applying a predetermined pressure to the cigarette wrapper near the end of the cigarette which is being tested, so as to deform the end to a degree which depends upon the compressibility of the end, a light source arranged to direct a beam of light onto the wrapper at or near the position where the pressure is applied, and light detecting means which is so positioned relative to the light source and the cigarette under test, that the beam of light is reflected from the cigarette directly towards the detecting means only in the case of a cigarette end which is not significantly deformed by the applied pressure.