Method and apparatus for inspecting inductively heatable aerosol-generating articles for the presence of a susceptor and desired article alignment

Abstract

The present invention relates to a method for testing an inductively heatable aerosol-generating article (1) for the presence of a susceptor (21) using at least one sensor (110) responsive to the susceptor (21) being at least one of conductive, magnetic, or magnetized. The present invention also relates to a method and apparatus for testing an inductively heatable aerosol-generating article (1) for desired article alignment at a particular article location within an article manufacturing facility, where the susceptor is provided for inductively heating an aerosol-forming substrate contained within the article, and the arrangement of the susceptor at or within the article is asymmetric with respect to the article's longitudinal axis. The method and apparatus include the use of at least a first sensor arranged and configured to detect the presence or absence of the susceptor at a first test site at the article location, where the presence of the susceptor at the first test site indicates the presence of the desired article alignment at the article location. The first sensor is responsive to the susceptor being at least one of conductive, magnetic, or magnetized, and is responsive to the presence of the susceptor at the first test site.

Description

[Technical field]

[0001] The present disclosure relates to a method for inspecting inductively heatable aerosol-generating articles for the presence of a susceptor, and further relates to a method and apparatus for inspecting inductively heatable aerosol-generating articles for the presence of a desired article alignment at a particular article location within an article manufacturing facility. [Background technology]

[0002] Inductively heatable aerosol-generating articles for generating inhalable aerosols are generally known from the prior art. Such articles typically comprise an aerosol-forming substrate and an inductively heatable susceptor disposed in thermal proximity or direct contact with the substrate. In use, the article is received in a cavity of an aerosol-generating device, where the susceptor is exposed to an alternating magnetic field. Depending on the magnetic and electrical properties of the susceptor, the magnetic field induces at least one of eddy currents or hysteresis losses in the susceptor, which causes the susceptor to heat up until it reaches a temperature sufficient to form an aerosol from the substrate. Summary of the Invention [Problem to be solved by the invention]

[0003] During the manufacture of such articles, it may happen that a susceptor is lost from the article, for example, as it is transported through the manufacturing equipment. Similarly, it may happen that an article is not provided with a susceptor at all. Furthermore, the article may not be properly aligned during transport through the manufacturing equipment. In particular, the longitudinal alignment of the article may be reversed 180 degrees relative to the desired alignment of the article, i.e., one end of the article that is meant to point in a particular direction may erroneously point in the opposite direction.

[0004] As a result, there is a need for a method and apparatus for testing inductively heatable aerosol-generating articles for the presence of a susceptor. [Means for solving the problem]

[0005] According to one aspect of the invention, there is provided a method of inspecting an inductively heatable aerosol-generating article for the presence of a susceptor, the susceptor being provided for inductively heating an aerosol-forming substrate contained within the article, the method comprising detecting the presence or absence of the susceptor using at least one sensor responsive to the susceptor being at least one of electrically conductive, magnetic, or magnetized.

[0006] According to the present invention, it is recognized that the presence of a susceptor can be reliably detected by examining the inherent electrical and magnetic properties of any susceptor that is conductive, or magnetic, or (when magnetic and exposed to an external magnetic field) magnetized. In particular, examining these properties advantageously allows the article to be inspected for the presence of a susceptor from outside the article, without even making the susceptor visible from the outside. This is due to the very nature of the electrical (conductive) and magnetic (magnetic or magnetized) properties of any susceptor, which affect the article environment even through the material of the article. In this case, the method and the equipment according to the present invention are superior to a mere optical inspection, which is not always possible, since the susceptor may be completely embedded in the article and therefore not visible from the outside. In addition, it is a further advantage that the inherent electrical and magnetic susceptor properties can be examined remotely using a suitable detector that responds to at least one of these properties.

[0007] As an example, the electrical and magnetic properties of the susceptor can cause detuning of the resonant frequency and amplitude of an oscillating LC resonant circuit when the susceptor is in close proximity to the inductor (L) of the LC resonant circuit. Further details of this detection mechanism are described below.

[0008] As another example, the susceptor may be magnetized causing the article to be surrounded by a magnetic field, which may be probed by a suitable sensor outside the article, for example by a reed switch, or a Hall effect sensor, or a magnetoresistance based sensor.

[0009] Alternatively, the susceptor may be magnetized and then passed through or near an induction loop or coil such that relative movement between the induction loop or coil and the magnetized susceptor causes a change in magnetic flux through the induction loop or coil. According to Faraday's law of induction, a change in magnetic flux induces a current through the induction loop or coil, which indicates the presence of a magnetized susceptor.

[0010] As a result, the method according to the invention makes it possible to reliably detect missing susceptors and therefore to sort out defective articles as early as possible before they enter the next step in the manufacturing process or before they are sold.

[0011] With reference to the above embodiments, the at least one sensor may comprise at least one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor (L) and a capacitor (C), a giant magnetoresistance-based sensor, or an anisotropic magnetoresistance-based sensor. Preferably, the at least one sensor is a non-optical sensor. As a result, the method according to the present invention may be presented as a method for non-optically inspecting an inductively heatable aerosol-generating article for the presence of a susceptor.

[0012] A reed switch is an electrical switch that is operated by an applied magnetic field. A reed switch may have a pair of metal contacts, at least one of which is magnetizable and flexible. The contacts may be normally open and may close in the presence of a magnetic field (such as that caused by a magnetized susceptor near the reed switch); that is, the end metal contacts are separated by a small gap when the switch is open. Alternatively, the contacts may be normally closed and may open when a magnetic field is applied. When the magnetic field is removed, the contacts in a reed switch return to their original position. The contacts may be encased in a hermetically sealed envelope.

[0013] In a Hall effect sensor, a thin strip of metal has a current applied along it. In the presence of a magnetic field (induced by a magnetized susceptor near the Hall effect sensor), electrons in the metal strip deflect toward one edge, creating a voltage gradient across the short side of the strip perpendicular to the applied current. The output voltage is directly proportional to the magnetic field strength through the Hall effect sensor. The Hall effect sensor may further comprise a threshold detection circuit. The threshold detection circuit may be configured to generate an output signal only when the magnetic field strength, and hence the output voltage, exceeds a certain threshold. In this configuration, the Hall effect sensor may act as a switch, sometimes referred to as a Hall effect switch.

[0014] As mentioned above, the inductive loop or coil may respond to the movement of a magnetized susceptor relative to the inductive loop or coil as this causes a change in magnetic flux through the inductive loop or coil. This detection mechanism may be particularly suitable for inspecting aerosol-generating articles for the presence of a passing susceptor.

[0015] Advantageously, the LC resonant circuit comprising an inductor (L) and a capacitor (C) is a versatile sensor since it responds to any susceptor type, i.e. conductive, or magnetic, or both conductive and magnetic. For example, if a conductive susceptor is placed in close proximity to the inductor of a vibrating LC resonant circuit, the magnetic field generated by the inductor induces eddy currents in the susceptor material. By Lenz's law, the eddy currents generate an opposing magnetic field that opposes the change in the magnetic field that generated the eddy currents. Hence, the eddy currents react back onto the source of the magnetic field, i.e. the LC resonant circuit, where the net inductive impedance of the LC resonant circuit decreases concomitantly with an increase in the vibration frequency. Vice versa, if the susceptor is magnetic (ferromagnetic or ferrimagnetic), i.e. if the susceptor comprises a material with high magnetic permeability, the presence of the susceptor in close proximity to the inductor of the LC resonant circuit increases the inductance of the LC resonant circuit concomitantly with a decrease in the vibration frequency. The change in the vibration magnitude may be detected by an amplitude modulation detector. The change in frequency may be detected by a frequency discrimination circuit, such as a phase-locked loop detector.

[0016] Depending on the sensor type, particularly its responsivity and its output signal, detecting the presence or absence of a susceptor using at least one sensor may include comparing the signal generated by the sensor with a respective reference signal. The reference signal may be predetermined to specifically indicate the presence of a susceptor. Depending on the sensor type used to detect a susceptor, the reference signal may be a predetermined reference value, a predetermined reference range, a predetermined reference threshold, or a predetermined reference profile, each of which is predetermined to indicate the presence of a susceptor. For example, in the case of a Hall sensor, the reference signal may be a predetermined reference threshold that the output voltage of the Hall effect sensor may have to exceed to indicate the presence of a magnetized susceptor. Vice versa, if the output voltage of the Hall effect sensor is below the predetermined reference threshold, it indicates the absence of a susceptor, i.e. the absence of a susceptor is detected. Similarly, in the case of an LC resonant circuit, the reference signal may be a predetermined frequency range in which the resonant frequency of the LC resonant circuit is shifted when a susceptor is in close proximity to the inductor of the LC resonant circuit. Vice versa, values ​​of the resonant frequency outside the predetermined frequency range indicate the absence of a susceptor.The reference signal is preferably achieved by pre-calibration of the sensor.

[0017] The method may further comprise the step of generating an optical signal when at least one of the presence of a susceptor or the absence of a susceptor is detected. Advantageously, the step of generating an optical signal may allow for an easy introduction of the method into existing manufacturing facilities that already comprise an optical inspection system. For example, an existing optical inspection system may be used previously to inspect aerosol-generating articles for certain manufacturing defects detectable by mere optical inspection. As a result, the existing optical inspection system may continue to be used without requiring a complete reintroduction of a new inspection system. In particular, an existing interface that operably couples the optical inspection system with the controller of the manufacturing equipment may continue to be used. Furthermore, the controller system itself may still be used without any modification. In particular, any functionality already implemented in the controller system that has been used previously to evaluate signals received from the optical inspection system may still be used to evaluate the detection results of the non-optical inspection method according to the invention. This is because the step of generating an optical signal advantageously provides for the conversion of a signal reflecting the detection results of at least one sensor into an optical signal that can be subsequently processed by the existing optical inspection system. In this case, the method may further comprise the step of detecting the optical signal using one or more optical detectors.

[0018] As mentioned above, in the case of a magnetic susceptor, the susceptor has the ability to be magnetized, whereby the susceptor and the article are surrounded by a permanent magnetic field, which may be used to detect the presence of the susceptor without the susceptor being visible from outside the article. As a result, the method may further comprise a step of magnetizing the susceptor before detecting the presence or absence of the susceptor using the at least one sensor. The step of magnetizing the susceptor may comprise using a magnetizer, in particular a permanent magnet or an electromagnet. The magnetizer is preferably disposed at a certain distance from the at least one sensor to avoid undesired interference effects between the magnetizer and the sensor.

[0019] According to another aspect of the invention, a method is provided for testing elongated inductively heatable aerosol-generating articles for the presence of a desired article alignment at a particular article location in an article manufacturing facility. A susceptor is provided for inductively heating an aerosol-forming substrate contained within the article. The arrangement of the susceptor at or within the article is asymmetric with respect to the length axis of the article. The method includes detecting the presence or absence of a susceptor at a first test site at the article location using a first sensor. The first sensor is responsive to a susceptor being at least one of conductive, magnetic, or magnetized. The first sensor is further responsive only to the presence of a susceptor at the first test site, and in particular to the presence of a susceptor at the first test site. The first test site is selected such that the presence of a susceptor at the first test site indicates the presence of a desired article alignment at the article location. The method further includes determining the presence of a desired article alignment at the article location when the presence of a susceptor at the first test site is detected.

[0020] According to the present invention, it is recognized that the overall general concept of the present invention, i.e., the use of at least one of the inherent electrical or magnetic properties of the susceptor to detect the presence or absence of the susceptor, may further be used to inspect an aerosol-generating article for the presence of a desired alignment, in particular a desired alignment with respect to the length axis of the article. The possibility of detecting a particular article alignment is substantially based on the fact that the susceptor arrangement has an asymmetry along the length axis of the article. This asymmetry essentially makes it possible to distinguish between different article alignments, since the position (in particular the distance of the susceptor relative to the first sensor at the first test site) is different for different article alignments. Hence, different article alignments cause different, in particular distinguishable, responses of the first sensor indicative of different article alignments.

[0021] As used herein, a first test site refers to a specific site at the location of an article within a manufacturing facility. First, a portion of the article is detected for the presence of a susceptor. The same is true for a second test site, which is further mentioned below.

[0022] In particular, the first sensor may be configured to respond exclusively to the presence of a susceptor at the first test site, while the susceptor is not responsive when the susceptor is at another site at the location of the article in the manufacturing facility. The term "not responsive" as used herein means that the first sensor is not capable of detecting the presence of a susceptor at sites other than the first test site. That is, the first sensor detects or indicates the absence of a susceptor at the first test site when the alignment of the article is such that a susceptor is present at sites other than the first test site. As a result, the first sensor may be configured to have a spatially limited detection range, in particular a spatially limited detection volume. The detection range or detection volume may depend on the range and strength of the effect caused by the specific electrical and magnetic properties of the susceptor, respectively. For example, the first sensor may have a spatially limited detection range of at least 4 centimeters, in particular at least 2 centimeters, preferably at least 1 centimeter, measured from the first sensor. Likewise, the first sensor may have a spatially limited detection volume of at least 64 cubic centimeters, in particular at least 8 cubic centimeters, preferably at least 1 cubic centimeter.

[0023] Typically the first sensor may comprise at least one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor and a capacitor, a giant magnetoresistance based sensor, or an anisotropic magnetoresistance based sensor. Preferably the first sensor is a non-optical sensor. Further features and advantages of the sensor types have already been mentioned above in relation to the at least one sensor according to the first aspect of the invention and therefore apply equally to the first sensor.

[0024] Further according to the first aspect of the present invention, detecting the presence or absence of a susceptor using a first sensor at the first test site may include comparing a first signal generated by the first sensor to a respective first reference signal, such that the first reference signal may be one of a first reference value, a first reference range, a first reference threshold, or a first reference profile, each of which is predetermined to be indicative of the presence of a susceptor at the first test site.

[0025] Further features and advantages of the first sensor result from the above description of the at least one sensor according to the first aspect of the invention and therefore apply equally to the first sensor.

[0026] The location of a particular article within an article manufacturing facility may be one of a pocket of a conveyor system, a packaging device, or a groove of a conveyor system, or a carrier of a conveyor system. A groove as used herein may be, for example, a vertical groove in a packaging machine, or a groove on the periphery of a transport drum, such as on a combiner.

[0027] As mentioned above, the use of a first sensor to detect the presence of a susceptor at the first test site allows for the active determination of the presence of a desired article alignment when the first test site is selected such that the presence of a susceptor at the first test site indicates the presence of a desired article alignment at the article location. However, it may happen that an article does not have a susceptor at all, for example because the susceptor was lost during transport through the manufacturing facility. Thus, it may happen that an article is properly aligned at the article location but does not have a susceptor. This situation cannot be distinguished from a situation where an article has a susceptor but is not aligned at the article location according to the desired article alignment, but is in an opposite article alignment, for example having a longitudinal extension that is reversed by 180 degrees relative to the desired article alignment. For example, with respect to a groove in a conveyor device, an elongated aerosol-generating article may be received in the groove in two different longitudinal alignments that are reversed by 180 degrees from each other along the length extension of the groove or the article. In one of the two longitudinal alignments, a particular end of the elongate article may point in a first direction along the length extension of the groove, and vice versa, in the other longitudinal alignment, the particular end of the article points in a second direction opposite the first direction.

[0028] Generally, only one of the two longitudinal alignments is the desired alignment, while the opposite longitudinal alignment is undesirable. For example, when packaging a group of elongated articles in a pack, the articles are disposed in pockets before being inserted into the pack. Generally, it is desired that all articles have the same longitudinal alignment in the pack, which requires that the articles are already properly aligned in the pockets.

[0029] To be able to distinguish between a situation where the article does not have a susceptor at all and a situation where the article has a susceptor but is aligned in an opposite alignment with a longitudinal extension that is reversed 180 degrees with respect to the desired article alignment, the method according to the second aspect of the invention may further comprise the step of detecting the presence or absence of a susceptor at a second test site at the article location using a second sensor. The second sensor responds to susceptors that are at least one of conductive, magnetic or magnetized. The second sensor further responds only to the presence of a susceptor at the second test site, in particular the presence of a susceptor at the second test site. The second test site is selected such that the presence of a susceptor at the second test site indicates the presence of an opposite article alignment at the article location with a longitudinal extension that is reversed 180 degrees with respect to the desired article alignment. The method further includes determining the presence of an alignment of oppositely oriented articles at the article location if the presence of a susceptor is detected at the second test site, or otherwise determining the absence of an article at the article location, or the absence of a susceptor at or within the article, if the absence of a susceptor is detected at the first test site and the second test site.

[0030] In this case, it is recognized that not only the presence or absence of a susceptor or article at a particular article location, but also the presence of one of the alignments of two articles may be specifically detected by using two sensors that detect the presence or absence of a susceptor at two different test sites for the article location.

[0031] The first test site, and therefore the first sensor, is preferably located around or at one end of the elongated article, and the second test site, and therefore the second sensor, is preferably located around or at the other end of the elongated article, where the sensors are most responsive to asymmetries in the susceptor arrangement relative to the length axis of the article.

[0032] The steps of detecting the presence or absence of a susceptor at the first location and detecting the presence or absence of a susceptor at the second location may be performed simultaneously, which advantageously speeds up the procedure and ultimate determination of the presence or absence of a susceptor and the presence or absence of a desired article alignment.

[0033] Like the first sensor, the second sensor may also comprise one of the sensor types already discussed above. As a result, the second sensor may comprise at least one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor and a capacitor, a giant magnetoresistance-based sensor, or an anisotropic magnetoresistance-based sensor. Like the first sensor, the second sensor may be a non-optical sensor.

[0034] Preferably, the first sensor and the second sensor are of the same type of sensor, which advantageously facilitates sensor readout and data processing and therefore the engineering effort.

[0035] Like the first sensor, the second sensor may be configured to respond exclusively to the presence of a susceptor at the second test site.

[0036] Furthermore, the second sensor may have a spatially limited detection range, in particular a spatially limited detection volume. For example, the second sensor may have a spatially limited detection range of at least 4 centimeters, in particular at least 2 centimeters, preferably at least 1 centimeter, measured from the first sensor. Similarly, the second sensor may have a spatially limited detection volume of at least 64 cubic centimeters, in particular at least 8 cubic centimeters, preferably at least 1 cubic centimeter.

[0037] Further consistent with the first sensor, the step of detecting the presence or absence of susceptors at the second test site using the second sensor may include comparing a second signal generated by the second sensor to a respective second reference signal. The second reference signal may be one of a second reference value, a second reference range, a second reference threshold, or a second profile, each of which is predetermined to indicate the presence of susceptors at the second test site. Alternatively, or additionally, the step of detecting the presence or absence of susceptors at the first site and the second test site using the first sensor and the second sensor, respectively, may include comparing a first signal generated by the first sensor to a second signal generated by the second sensor.

[0038] Further features and advantages of the second sensor result from the above description of the at least one sensor according to the invention and of the first sensor and therefore apply equally to the second sensor.

[0039] As already mentioned above, it may be desirable to upgrade an existing manufacturing facility with a non-optical inspection system, for example when changing the design of an article such that the susceptor is no longer visible from the outside of the article. In particular, the upgrade of an existing manufacturing facility may advantageously involve an existing optical inspection system already installed in the manufacturing facility. Thus, the method according to the second aspect of the invention may further comprise the step of generating a first optical signal when at least one of the presence of a susceptor at the first test site or the absence of a susceptor at the first test site is detected. Similarly, the method may further comprise the step of generating a second optical signal when at least one of the presence of a susceptor at the second test site or the absence of a susceptor at the second test site is detected. Advantageously, the steps of generating a first optical signal and generating a second optical signal each provide for converting signals reflecting the detection results of the first sensor and the second sensor into respective optical signals. In order to read out and further process these optical signals, the method according to the second aspect of the invention may further comprise the step of detecting the first optical signal, and, if realized, the second signal, using one or more optical detectors. As mentioned above, the optical detector is preferably an optical detector already installed in the manufacturing facility.

[0040] Depending on the specific sensor type, it may be necessary to magnetize the susceptor to make it detectable. As a result, the method according to the second aspect of the invention may further comprise a step of magnetizing the susceptor before the step of detecting the presence or absence of the susceptor at the first test site using the first sensor and, if realized, before the step of detecting the presence or absence of the susceptor at the second test site using the second sensor. The step of magnetizing the susceptor may comprise using a magnetizer, in particular a permanent magnet or an electromagnet. The magnetizer is preferably arranged at a certain distance with respect to the first sensor and the second sensor (if present) to avoid undesired interference effects between the magnetizer and the sensor.

[0041] According to yet another aspect of the invention, there is provided an apparatus for testing elongated inductively heatable aerosol-generating articles for the presence of a desired article alignment at a particular article location in an article manufacturing facility, where a susceptor is provided for inductively heating an aerosol-forming substrate contained within the article, and where the arrangement of the susceptor at or within the article is asymmetrical with respect to a length axis of the article. The apparatus includes a first sensor arranged and configured to detect the presence or absence of the susceptor at a first test site at the article location, where the presence of the susceptor at the first test indicates the presence of the desired article alignment at the article location. The first sensor is responsive to the susceptor being at least one of conductive, magnetic, or magnetized. The first sensor is further responsive to the presence of the susceptor at the first test site, and in particular is responsive only to the presence of the susceptor at the first test site.

[0042] The arrangement allows for actively determining the presence of a desired alignment of articles at the first test site, as described above in relation to the method according to the second aspect of the invention, and for this reason any of the advantages described above in relation to the method apply equally to the arrangement described herein.

[0043] The equipment may further include an electrical circuit operatively connected to the first sensor and configured to determine the presence of a desired article alignment at the article location in response to the first sensor detecting the presence of a susceptor at the first test site. The electrical circuit may, for example, provide a signal indicative of the presence of a desired article alignment at the article location.

[0044] To allow for unambiguous identification of whether an article is present, or at any rate includes a susceptor, and whether the article is aligned according to the desired article alignment, the apparatus may further comprise a second sensor arranged and configured to detect the presence or absence of a susceptor at the second test site at the article location. The presence of a susceptor at the second test site indicates the presence of an opposite article alignment at the article location having a longitudinal extension that is reversed 180 degrees relative to the desired article alignment. The second sensor is responsive to a susceptor being at least one of conductive, magnetic, or magnetized. The second sensor is further responsive to the presence of a susceptor at the second test site, and in particular is responsive only to the presence of a susceptor at the second test site.

[0045] Like the first sensor, the electrical circuit may also be operatively connected to the second sensor and configured to determine the presence of an opposing alignment of articles at the article location in response to the second sensor detecting the presence of a susceptor at the second test site, or to determine the absence of an article at the article location, or the absence of a susceptor at or within the article in response to the first sensor and the second sensor detecting the absence of a susceptor at the first test site and the second test site. Alternatively, the equipment may include a separate electrical circuit operatively connected to the second sensor and configured as described above.

[0046] The installation is preferably configured to carry out the method according to the invention.

[0047] As a result, the first sensor and the second sensor (if present) may correspond to the first and second sensors described above with respect to the method according to the invention, and therefore any features and advantages described above with respect to this method apply equally to the first and second sensors of the installation described herein.

[0048] At least one of the first sensor and the second sensor (if present) may comprise one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor and a capacitor, a giant magnetoresistance based sensor, or an anisotropic magnetoresistance based sensor. Preferably, the first sensor and the second sensor are of the same sensor type.

[0049] At least one of the first sensor and the second sensor (if present) may be a non-optical sensor.

[0050] At least one of the first sensor and the second sensor (if present) may be configured to respond exclusively to the presence of a susceptor at the first site and the second test site, respectively.

[0051] At least one of the first sensor and the second sensor (if present) may have a spatially limited detection range, in particular a spatially limited detection volume.

[0052] At least one of the first sensor and the second sensor (if present) may have a spatially limited detection range of at least 4 centimetres, in particular at least 2 centimetres, preferably at least 1 centimetre, measured from the first sensor.

[0053] At least one of the first sensor and the second sensor (if present) may have a spatially limited detection volume of at least 64 cubic centimeters, in particular at least 8 cubic centimeters, preferably at least 1 cubic centimeter.

[0054] Further consistent with the method according to the second aspect of the invention, the installation may further comprise a magnetizer, in particular a permanent magnet or an electromagnet, arranged and configured to magnetize the susceptor of the article. The magnetizer may be provided, in particular when the first sensor and the second sensor (if present) are configured to respond to a magnetic field as described above. The magnetizer is preferably arranged at a distance relative to the first sensor and the second sensor (if present) to avoid undesirable interference effects between the magnetizer and the sensors.

[0055] The equipment may further comprise a first light indicator, in particular a first light emitting diode, operably connected to the first sensor or electrical circuit. The first light indicator may be configured to provide a first light signal in response to the first sensor detecting the presence of a susceptor at the first test site or in response to an electrical circuit determining the presence of a desired alignment of articles at the article location. Similarly, the equipment may comprise a second light indicator, in particular a second light emitting diode, operably connected to the second sensor or electrical circuit. The second light indicator may be configured to provide a second light signal in response to the second sensor detecting the presence of a susceptor at the second test site or in response to an electrical circuit determining the presence of an oppositely oriented alignment of articles at the article location. As mentioned above, the first light indicator and the second light indicator may advantageously be used to convert signals reflecting the detection results of the first sensor and the second sensor into respective light signals, which may then be read out and further processed by an optical inspection system already installed in the equipment. In this case, the installation may further comprise at least one optical detector, in particular at least one photodiode or at least one camera, arranged and configured to detect at least one of the first optical signal or the second optical signal.

[0056] Generally, the equipment may be configured to test a single aerosol-generating article. Alternatively or additionally, the equipment may be configured to test a plurality, in particular a group of aerosol-generating articles. The equipment may then comprise a plurality of first sensors, second sensors, electrical circuits, first light indicators and second light indicators, in particular one each for each article to be tested. Preferably, at least two of the first sensor, second sensor, electrical circuits, first light indicators and second light indicators may each form a test unit for testing one of the articles. It is also possible for the equipment to comprise a single sensor, or a single first sensor and a single second sensor, in order to globally test a plurality, in particular a group of aerosol-generating articles, for the presence or absence of one or more susceptors. In particular, a single sensor, or a single first sensor and a single second sensor, may be configured to comprehensively detect the number of susceptors present in a plurality, particularly a group of aerosol-generating articles, or vice versa, the number of susceptors absent in a plurality, particularly a group of aerosol-generating articles, or both the number of susceptors present and the number of susceptors absent in a plurality, particularly a group of aerosol-generating articles.

[0057] Further features and advantages of the magnetizer, the first and second light indicators and the at least one optical detector have already been described above in relation to the method according to the invention and apply equally to the installation described herein.

[0058] The term "aerosol-generating article" as used herein refers to an article comprising at least one aerosol-forming substrate which, when heated, releases a volatile compound capable of forming an aerosol. The aerosol-generating article may also refer to a heated aerosol-generating article, i.e. at least one aerosol-forming substrate contained within the article is intended to be heated, rather than combusted, to release a volatile compound capable of forming an aerosol. The aerosol-generating article may also be a consumable product, in particular a consumable product for single use. For example, the article may be a cartridge comprising a liquid aerosol-forming substrate to be heated. Alternatively, the article may be a rod-shaped article, in particular a tobacco article.

[0059] According to the invention, the article further comprises a susceptor positioned in thermal proximity or thermal contact with the aerosol-forming substrate. In use, the susceptor is inductively heatable by an alternating magnetic field until it reaches a temperature sufficient to volatilize components of the aerosol-forming substrate capable of forming an inhalable aerosol. For example, the article may be configured to be received within a cavity of an aerosol generating device. There, an inductive heating arrangement of the device may generate an alternating magnetic field that is used to inductively heat the susceptor.

[0060] The term "susceptor" as used herein refers to an element that has the ability to convert electromagnetic energy into heat when subjected to an alternating magnetic field. This may be the result of at least one of hysteresis loss or eddy currents induced in the susceptor, depending on the electrical and magnetic properties of the susceptor material. Hysteresis loss occurs in ferromagnetic or ferrimagnetic susceptors due to magnetic domains in the material that are switched under the influence of the alternating electromagnetic field. Eddy currents may be induced if the susceptor is conductive. In the case of conductive ferromagnetic or ferrimagnetic susceptors, heat can be generated due to both eddy currents and hysteresis loss. As a result, being at least one of conductive or magnetic is an inherent property of the susceptor. Thus, a susceptor according to the present invention may be at least one of conductive or magnetic. The term "magnetic susceptor" as used herein refers to a susceptor that is either ferromagnetic or ferrimagnetic. This is an inherent property of ferromagnetic or ferrimagnetic materials to be magnetized by an external magnetic field and to remain magnetized after the external magnetic field is removed. As a result, the term "magnetized susceptor" as used herein refers to a ferromagnetic or ferrimagnetic susceptor that is magnetized by an external magnetic field and that remains magnetized after the external magnetic field is removed.

[0061] The term "aerosol-forming substrate" as used herein means a substrate formed from or including an aerosol-forming material capable of releasing a volatile compound upon heating to generate an aerosol. The aerosol-forming substrate is intended to be heated, rather than combusted, to release the aerosol-forming volatile compound. The aerosol-forming substrate may be a solid aerosol-forming substrate or a liquid aerosol-forming substrate or a gel-like aerosol-forming substrate, or any combination thereof. That is, the aerosol-forming substrate may include, for example, both solid and liquid components. The aerosol-forming substrate may include a tobacco-containing material that contains volatile tobacco flavor compounds that are released from the substrate upon heating. Alternatively, or additionally, the aerosol-forming substrate may include a non-tobacco material. The aerosol-forming substrate may further include an aerosol former. Examples of suitable aerosol formers are glycerin and propylene glycol. The aerosol-forming substrate may also include other additives and ingredients, such as nicotine or flavorings. The aerosol-forming substrate may also be a paste-like material, a sachet of porous material containing the aerosol-forming substrate, or loose tobacco mixed with, for example, a gelling or adhesive agent, which may include a common aerosol former such as glycerin, which is compressed or molded into a plug.

[0062] The following provides a non-exhaustive list of non-limiting examples, any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0063] Example Ex1: A method of inspecting an inductively heatable aerosol-generating article for the presence of a susceptor, the susceptor being provided for inductively heating an aerosol-forming substrate contained within the article, the method comprising detecting the presence or absence of the susceptor using at least one sensor responsive to the susceptor being at least one of conductive, magnetic or magnetized. Example Ex2: The method according to example Ex1, wherein the at least one sensor comprises at least one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor and a capacitor, a giant magnetoresistance-based sensor, or an anisotropic magnetoresistance-based sensor. Example Ex3: The method according to any one of the preceding examples, wherein at least one sensor is a non-optical sensor. Example Ex4: A method according to any one of the preceding examples, wherein detecting the presence or absence of a susceptor using at least one sensor comprises comparing a signal generated by the sensor with a respective reference signal. Example Ex5: The method according to example Ex4, wherein the reference signal is one of a reference value, a reference range, a reference threshold, or a reference profile, each of which is predetermined to indicate the presence of a susceptor. Embodiment Ex6: The method according to any one of the preceding embodiments, wherein the method further comprises the step of generating an optical signal when at least one of the presence of a susceptor or the absence of a susceptor is detected. Example Ex7: The method according to example Ex6, wherein the method further comprises detecting the optical signal using one or more optical detectors. Example Ex8: The method according to any one of the preceding examples, wherein the method further comprises magnetizing the susceptor before detecting the presence of the susceptor using the at least one sensor. Example Ex9: A method of inspecting elongated inductively heatable aerosol-generating articles for the presence of a desired article alignment at a particular article location in an article manufacturing facility, wherein a susceptor is provided for inductively heating an aerosol-forming substrate contained within the article, and the arrangement of the susceptor at or within the article is asymmetric relative to a length axis of the article, the method comprising: - detecting the presence or absence of a susceptor using a first sensor at a first test site at the article location, the first sensor being responsive to a susceptor being at least one of conductive, magnetic, or magnetized, and responsive to the presence of a susceptor at the first test site, the first test site being selected such that the presence of a susceptor at the first test site indicates the presence of a desired article alignment at the article location; - determining the presence of a desired article alignment at the article location if the presence of a susceptor at the first test site is detected. Example Ex10: The method according to example Ex9, wherein the first sensor is configured to respond exclusively to the presence of a susceptor at the first test site. Example Ex11: The method according to any one of examples Ex9 or Ex10, wherein the first sensor has a spatially limited detection range, in particular a spatially limited detection volume. Example Ex12: The method according to example Ex11, wherein the first sensor has a spatially limited detection range of at least 4 centimeters, in particular at least 2 centimeters, preferably at least 1 centimeter, measured from the first sensor. Example Ex13: The method according to example Ex11, wherein the first sensor has a spatially limited detection volume of at least 64 cubic centimeters, in particular at least 8 cubic centimeters, preferably at least 1 cubic centimeter. Example Ex14: The method according to any one of examples Ex9 to Ex13, wherein the first sensor comprises at least one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor and a capacitor, a giant magnetoresistance-based sensor, or an anisotropic magnetoresistance-based sensor. Example Ex15: The method according to any one of examples Ex9 to Ex14, wherein the first sensor is a non-optical sensor. Example Ex16: The method according to any one of examples Ex9 to Ex15, wherein the step of detecting the presence or absence of a susceptor using a first sensor at the first test site comprises comparing a first signal generated by the first sensor to a respective first reference signal. Example Ex17: A method according to any one of examples Ex9 to Ex16, wherein the first reference signal is one of a first reference value, a first reference range, a first reference threshold, or a first reference profile, each of which is predetermined to indicate the presence of a susceptor at the first test site. Example Ex18: - detecting the presence or absence of a susceptor using a second sensor at a second test site at the article location, the second sensor being responsive to a susceptor being at least one of conductive, magnetic, or magnetized, and the second test site being selected such that the presence of a susceptor at the second test site indicates the presence of an opposite article alignment at the article location having a longitudinal extension that is reversed 180 degrees relative to the desired article alignment; - determining the presence of an opposing alignment of articles at the article location if the presence of a susceptor is detected at the second test site, or otherwise determining the absence of an article at the article location, or the absence of a susceptor at or within the article, if the absence of a susceptor is detected at the first test site and the second test site. Example Ex19: A method according to example Ex18, wherein at the article location, a first test site, particularly a first test sensor, is located around one end or end portion of the elongated article, and a second test site, particularly a second sensor, is located around the other end or end portion of the elongated article. Example Ex20: The method according to any one of example Ex18 or example Ex19, wherein the steps of detecting the presence or absence of a susceptor at the first location and detecting the presence or absence of a susceptor at the second location are performed simultaneously. Example Ex21: The method according to any one of examples Ex18 to Ex20, wherein the second sensor comprises at least one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor and a capacitor, a giant magnetoresistance-based sensor, or an anisotropic magnetoresistance-based sensor. Example Ex22: The method according to any one of examples Ex18 to Ex21, wherein the second sensor is a non-optical sensor. Example Ex23: The method according to any one of examples Ex18 to Ex22, wherein the first sensor and the second sensor are of the same type. Example Ex24: The method according to any one of examples Ex18-Ex23, wherein the second sensor is configured to respond exclusively to the presence of a susceptor at the second test site. Example Ex25: The method according to any one of examples Ex18 to Ex24, wherein the second sensor has a spatially limited detection range, in particular a spatially limited detection volume. Example Ex26: The method according to example Ex25, wherein the second sensor has a spatially limited detection range of at least 4 centimeters, in particular at least 2 centimeters, preferably at least 1 centimeter, measured from the first sensor. Example Ex27: The method according to example Ex25, wherein the second sensor has a spatially limited detection volume of at least 64 cubic centimeters, in particular at least 8 cubic centimeters, preferably at least 1 cubic centimeter. Example Ex28: The method according to any one of examples Ex18 to Ex27, wherein the step of detecting the presence or absence of a susceptor using the second sensor at the second test site may comprise comparing a second signal generated by the second sensor with a second reference signal, respectively, and / or the step of detecting the presence or absence of a susceptor using the first sensor and the second sensor at the first site and the second test site, respectively, may comprise comparing a first signal generated by the first sensor with a second signal generated by the second sensor. Example Ex29: A method according to example Ex28, wherein the second reference signal is one of a second reference value, a second reference range, a second reference threshold, or a second profile, each of which is predetermined to indicate the presence of a susceptor at the second test site. Example Ex30: The method according to any one of examples Ex9 to Ex29, further comprising generating a first light signal when at least one of a presence of a susceptor at the first test site or an absence of a susceptor at the first test site is detected.

[0064] Example Ex31: The method according to any one of examples Ex18 to Ex29, further comprising the step of generating a second light signal when at least one of a presence of a susceptor at the second test site or an absence of a susceptor at the second test site is detected. Example Ex32: The method according to any one of example Ex30 or example Ex31, further comprising detecting the first optical signal and, if implemented, the second optical signal using one or more optical detectors. Example Ex33: The method according to any one of examples Ex9 to Ex32, further comprising a step of magnetizing the susceptor prior to the step of detecting the presence or absence of the susceptor using a first sensor at the first test site, and, if implemented, prior to the step of detecting the presence or absence of the susceptor using a second sensor at the second test site. Example Ex34: The method according to any one of examples Ex9 to Ex33, wherein the location of the particular article within the article manufacturing facility is one of a pocket of a conveyor system or a packaging system, or a groove of a conveyor system, or a carrier of a conveyor system. Example Ex35: Installation for inspecting elongated inductively heatable aerosol-generating articles for the presence of a desired article alignment at a particular article location in an article manufacturing facility, in particular for carrying out the method according to any one of examples Ex9 to Ex34, wherein a susceptor is provided for inductively heating an aerosol-forming substrate contained within the article, wherein the arrangement of the susceptor at or within the article is asymmetric with respect to a length axis of the article, and wherein the apparatus comprises a first sensor arranged and configured to detect the presence or absence of the susceptor at a first test site at the article location, wherein the presence of the susceptor at the first test indicates the presence of a desired article alignment at the article location, and wherein the first sensor is responsive to the susceptor being at least one of a conductive, a magnetic or a magnetized state, and is responsive to the presence of the susceptor at the first test site. Example Ex36: An apparatus according to example Ex35, further comprising a second sensor arranged and configured to detect the presence or absence of a susceptor at a second test site at the article location, the presence of a susceptor at the second test indicates the presence of an opposite article alignment at the article location having a longitudinal extension that is reversed 180 degrees relative to the desired article alignment, the second sensor being responsive to a susceptor being at least one of conductive, magnetic, or magnetized, and responsive to the presence of a susceptor at the second test site. Example Ex37: An apparatus according to any one of examples Ex35 or Ex36, further comprising an electrical circuit operably connected to the first sensor and configured to determine the presence of a desired article alignment at the article location in response to the first sensor detecting the presence of a susceptor at the first test site. Example Ex38: An apparatus according to example Ex37, wherein the electrical circuit is operably connected to the second sensor and configured to determine the presence of an alignment of oppositely oriented articles at the article location in response to the second sensor detecting the presence of a susceptor at the second test site, or to otherwise determine the absence of an article at the article location, or the absence of a susceptor at or within the article, in response to the first sensor and the second sensor detecting the absence of a susceptor at the first test site and the second test site. Example Ex39: An apparatus according to any one of examples Ex35 to Ex38, wherein the first sensor is configured to respond exclusively to the presence of a susceptor at the first test site. Example Ex40: Installation according to any one of examples Ex34 to Ex39, wherein the first sensor has a spatially limited detection range, in particular a spatially limited detection volume. Example Ex41: Installation according to example Ex40, wherein the first sensor has a spatially limited detection range of at least 4 centimeters, in particular at least 2 centimeters, preferably at least 1 centimeter, measured from the first sensor. Example Ex42: An installation according to example Ex40, wherein the first sensor has a spatially limited detection volume of at least 64 cubic centimeters, in particular at least 8 cubic centimeters, preferably at least 1 cubic centimeter. Example Ex43: The apparatus according to any one of examples Ex35 to Ex42, wherein the first sensor comprises at least one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor and a capacitor, a giant magnetoresistance-based sensor, or an anisotropic magnetoresistance-based sensor. Example Ex44: The installation according to any one of examples Ex35 to Ex43, wherein the first sensor is a non-optical sensor. Example Ex45: An arrangement according to any one of examples Ex36 to Ex44, wherein the second sensor is configured to respond exclusively to the presence of a susceptor at the second test site. Example Ex46: Installation according to any one of examples Ex36 to Ex45, wherein the second sensor has a spatially limited detection range, in particular a spatially limited detection volume. Example Ex47: Installation according to example Ex46, wherein the second sensor has a spatially limited detection range of at least 4 centimeters, in particular at least 2 centimeters, preferably at least 1 centimeter, measured from the first sensor. Example Ex48: An installation according to example Ex46, wherein the second sensor has a spatially limited detection volume of at least 64 cubic centimeters, in particular at least 8 cubic centimeters, preferably at least 1 cubic centimeter. Example Ex49: The apparatus according to any one of examples Ex36 to Ex48, wherein the second sensor comprises at least one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor and a capacitor, a giant magnetoresistance-based sensor, or an anisotropic magnetoresistance-based sensor. Example Ex50: The apparatus according to any one of examples Ex36 to Ex49, wherein the second sensor is a non-optical sensor. Example Ex51: An installation according to any one of examples Ex36 to Ex50, wherein the first sensor and the second sensor are of the same sensor type. Example Ex52: The apparatus according to any one of examples Ex35 to Ex51, further comprising a magnetizer, in particular a permanent magnet or an electromagnet, arranged and configured to magnetize the susceptor of the article. Example Ex53: The equipment according to any one of examples Ex35 to Ex52, further comprising a first light indicator, in particular a first light emitting diode, operably connected to the first sensor or electrical circuitry and configured to provide a first light signal in response to the first sensor detecting the presence of a susceptor at the first test site or in response to the electrical circuitry determining the presence of a desired article alignment at the article location. Example Ex54: The apparatus according to any one of examples Ex36 to Ex53, further comprising a second light indicator, in particular a second light emitting diode, operably connected to a second sensor or electrical circuit and configured to provide a second light signal in response to the second sensor detecting the presence of a susceptor at the second test site or in response to the electrical circuit determining the presence of an alignment of oppositely oriented articles at the article location. Example Ex55: An apparatus according to any one of examples Ex53 or Ex54, further comprising at least one optical detector, in particular at least one photodiode or at least one camera, arranged and configured to detect at least one of the first optical signal or the second optical signal.

[0065] Some embodiments will now be further described with reference to the figures. [Brief description of the drawings]

[0066] [Figure 1] FIG. 1 illustrates a schematic diagram of an exemplary embodiment of an inspection method according to a first aspect of the invention. [Diagram 2] 2 to 4 diagrammatically illustrate a first embodiment of an inspection installation according to a third aspect of the present invention. [Diagram 3] 2 to 4 diagrammatically illustrate a first embodiment of an inspection installation according to a third aspect of the present invention. [Figure 4] 2 to 4 diagrammatically illustrate a first embodiment of an inspection installation according to a third aspect of the present invention. [Diagram 5] 5 to 8 diagrammatically illustrate a second embodiment of an inspection installation according to the third aspect of the present invention. [Figure 6] 5 to 8 diagrammatically illustrate a second embodiment of an inspection installation according to the third aspect of the present invention. [Figure 7] 5 to 8 diagrammatically illustrate a second embodiment of an inspection installation according to the third aspect of the present invention. [Figure 8] 5 to 8 diagrammatically illustrate a second embodiment of an inspection installation according to the third aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0067] 1 illustrates in a schematic manner an exemplary embodiment of the method according to the first aspect of the invention. The method allows to inspect an aerosol-generating article 1 for the presence of a susceptor 21. As will be described further, both such articles 1 are generally known from the prior art. They typically comprise an aerosol-forming substrate 22 and an inductively heatable susceptor 21 arranged in thermal proximity or in direct contact with the substrate 22. In use, the article 1 is received in a cavity of an aerosol-generating device (not shown), where the susceptor 21 is exposed to an alternating magnetic field. Depending on the magnetic and electrical properties of the susceptor 21, the magnetic field induces at least one of eddy currents or hysteresis losses in the susceptor 21, which causes the susceptor 21 to heat up until it reaches a temperature sufficient to form an aerosol from the substrate 22.

[0068] In this embodiment, the elongated article 1 is substantially rod-shaped. As can be seen in FIG. 1, the article 1 comprises five elements, namely a first support element 10, a base element 20, a second support element 30, an aerosol cooling element 40, and a mouthpiece element 50, arranged consecutively one after the other in coaxial alignment along the longitudinal axis 4 of the article 1. The first support element 10 is arranged at the distal end 2 of the elongated article 1, while the mouthpiece element 50 is arranged at the proximal end 3 of the article 1. All five elements 10, 20, 30, 40, 50 are cylindrical elements having substantially the same diameter so as to form a cylindrical rod. The element assembly is surrounded by an outer wrapper 60 made of cigarette paper, which holds together the elements 10, 20, 30, 40, 50. The outer wrapper 60 may be wrapped around the aforementioned elements such that the free ends of the wrapper 60 overlap each other. The wrapper 60 may further comprise an adhesive that adheres the overlapping free ends of the wrapper to one another.

[0069] The base element 20 comprises a heated aerosol-forming substrate 22. For example, the aerosol-forming substrate 22 may comprise a crimped sheet of homogenized tobacco material containing glycerin as an aerosol former. Within the substrate 22, the base element further comprises a susceptor 21 in direct contact with the substrate 22. In this embodiment, the susceptor 21 comprises a metal strip made of ferromagnetic stainless steel that is embedded within the aerosol-forming substrate 22.

[0070] Due to the aerosol-forming substrate 22 surrounding the susceptor 21 and due to the first support element 10 and the second support element 30 covering the axial end faces of the cylindrical substrate element 20, the susceptor 21 is not visible from the outside of the article 1 by simple optical inspection.

[0071] According to the present invention, it is suggested to detect the presence or absence of the susceptor 21 in the article 1 using at least one sensor 110 that responds to the inherent electrical and magnetic properties of the susceptor 21, i.e., at least one of conductive or magnetic, and the property of the susceptor 21 to become magnetized (when magnetic and exposed to an external magnetic field). As mentioned above, the susceptor 21 in this embodiment is made of ferromagnetic stainless steel. As a result, the susceptor 21 is both conductive and magnetic. In addition, the susceptor 21 in this embodiment is exposed to an external magnetic field before inspection. Thus, since the susceptor material is ferromagnetic, the susceptor 21 is also magnetized and is therefore surrounded by a static magnetic field as shown by the dotted magnetic field lines 25 in FIG. 1. In contrast, the aerosol-forming substrate 22 and other elements of the article are neither conductive nor highly magnetically permeable. Due to this, the magnetic field lines 25 easily penetrate other parts of the article 1 and enter the outer periphery of the article 1. As a result, the magnetic field may advantageously be used to detect the presence of the susceptor 21 within the article 1 from outside the article 1, even though the susceptor 21 is not visible.

[0072] In general, several sensor types are available for probing the presence of a magnetic field. In this embodiment, the sensor 110 comprises a reed switch 111 disposed next to the base element 20 of the article 1 so as to be penetrated by the magnetic field lines 25 of the magnetized susceptor 21. The reed switch 111 comprises a pair of magnetizable and flexible metallic contacts 112 encased within a hermetically sealed envelope 113. The contacts 112 are normally open and close when a magnetic field is present.

[0073] 1, the reed switch 111 is operably connected to an electrical circuit 150 and includes a light emitting diode (LED) 160 and a power source 170. As a result, when the magnetized susceptor 21 is brought into close proximity to the reed switch 111, or vice versa, the reed switch 111 is closed, causing a current to flow through the electrical circuit 150, which in turn causes the LED 160 to emit a light signal. In contrast, when a susceptor is absent within the article 1, the reed switch 111 is open and the LED 160 is off, thereby indicating the absence of a susceptor within the article 1.

[0074] This general concept of the present invention for detecting the presence of a susceptor in an aerosol-generating article may also be used to inspect articles for the presence of desired article alignment at specific article locations within an article manufacturing facility.

[0075] In this regard, Figures 2 to 4 show an article carriage or so-called pocket 208 of a conveyor device that may be used in an article manufacturing facility to pre-arrange a group of aerosol-generating articles 1, for example, before they are inserted into a pack. Generally, it is desirable for all articles 1 to have the same longitudinal alignment in the pack. This requires that the articles 1 are already properly aligned in the pocket 208, so that the distal ends 2 of all articles point in the same direction. This situation is shown in Figure 3. Any articles 1 with opposite article alignments are desirably identified before inserting the articles 1 into the pack. Such a situation is illustrated in Figure 4, where one of the articles 1 (the second article from the left) has its distal end 2 pointing in the opposite direction compared to the other articles. That is, the longitudinal extension of this article 1 is reversed by 180 degrees with respect to the other articles 1.

[0076] In accordance with the present invention, the asymmetrical arrangement of susceptor 21 relative to the length extension of article 1 is exploited to inspect article 1 for the presence of desired longitudinal article alignment.

[0077] As shown in Figure 2, a pocket 208 is provided with a test fixture 200 that includes a plurality of first sensors 210 that are configured similarly to the sensors 110 shown in Figure 1. That is, the first sensors 210 are responsive to a permanent magnetic field induced by a magnetized susceptor. In particular, the first sensors 210 may each include a reed switch as described above.

[0078] Each of the first sensors 210 is associated with a particular location 205 of the article 201 received within the pocket 208. Specifically, each of the first sensors 210 is disposed in a respective first test site 201 at the associated article location 205. Each first test site 201 is located about where the base element and susceptor 21 of the respective article 1 should be when the articles 1 are disposed according to a desired article alignment. As a result, in this embodiment, the first sensors 210 are disposed near where the distal end portion of each article 1 should be.

[0079] As a result, when the article 1 with the previously magnetized susceptor 21 is arranged according to the desired article alignment, each first sensor 210 detects the presence of the susceptor 21 due to the presence of a magnetic field proximate to each first sensor 210. In contrast, when the article is in the opposite article alignment (see article 1 second from the left in FIG. 4), there is no response of each first sensor 210 due to the absence of a magnetic field proximate to this first sensor 210.

[0080] However, when using only one sensor at each article location, this situation may not be distinguishable from a situation where article 1 does not have a susceptor at all, or where an article is absent at the respective article location 205. To be able to specifically distinguish between these situations, the testing equipment 200 may further comprise a plurality of second sensors 220, as shown in Figure 5. Each of the second sensors 220 is disposed in the respective second test site 202 at an associated article location 205 near where a proximal end portion of article 1 should be when article 1 is disposed in pocket 208 according to a desired article alignment, or vice versa. Thus, when an article 1 with a previously magnetized susceptor 21 is misaligned in the opposite article alignment as shown in Figure 6 (see article 1 second from the left in Figure 6), the magnetic field of the magnetized susceptor 21 is proximate to the associated second test site 202, which causes the second sensor 220 to respond to the magnetic field. As a result, the second sensor 220 detects the presence of a susceptor at the second test site 220, which in turn indicates the presence of the opposite article alignment.

[0081] Further, as shown in FIG. 7 (see the second article 1 from the left in FIG. 7), if the article does not have a susceptor 21, each of the first sensors 210 and each of the second sensors 220 will detect the absence of a susceptor at the first test site 201 and the second test site 202, respectively. Taken together, this result indicates a total absence of a susceptor in the article 1, regardless of whether the article 1 is disposed corresponding to a desired article alignment or a counter article alignment. Similarly, this result may indicate a lack of an article at each article location 25, as shown in FIG. 8 (see the second article location 25 from the left in FIG. 8).

[0082] Each of the first sensors 210 in the embodiment shown in Figures 2-4, and each of the first sensor 210 and second sensor 220 in the embodiments shown in Figures 5-8, are operably coupled to a respective electrical circuit similar to the electrical circuit 160 shown in Figure 1.

[0083] Referring to the embodiment shown in Figures 2-4, each electrical circuit may include a power source 270 and a light-emitting diode 260 (which is a light indicator) that generates a light signal in response to a first sensor 210 that detects the presence of a susceptor 21 at the first test site 201.

[0084] 5-8 , each electrical circuit may include a power source 270 and a first light emitting diode 261 (which is a first light indicator) that generates a first signal in response to a first sensor 210 detecting the presence of a susceptor 21 at the first test site 201. Additionally, each electrical circuit may include a second light emitting diode 262 (which is a first light indicator) that generates a second signal in response to a respective second sensor 220 detecting the presence of a susceptor 21 at the respective second test site 202.

[0085] The respective electric circuits, in particular the respective power supply 270, the light-emitting diodes 260, 261, 262 and the respective sensors 210, 220 may be integrated in the pocket 208. Even more particularly, the respective power supply 270, the respective light-emitting diode(s) 260, 261, 262 and the respective sensor(s) 210, 220 associated with a particular item location 25 may form an inspection unit of the inspection installation 200. Each inspection unit is preferably independent of the inspection units of the other item locations in the pocket 20. Each inspection unit is preferably powered by a single power supply. This applies in particular to the inspection installation 200 according to figures 5 to 8, which comprises two sensors 210, 220 and two light-emitting diodes 261, 262 for each item location 25. The two sensors 210, 220 and the two light-emitting diodes 261, 262 are preferably powered together by a common power supply 270 associated with the respective item location 25.

[0086] As described above, the light emitting diodes 260, 261, 262 convert the responses of the respective first sensor 210 and second sensor 220 into first and second optical signals indicative of the presence or absence of the susceptor 21 at the first test site 201 and the second test site 202, respectively. Together, each pair of the first and second optical signals indicates the presence or absence of a desired article alignment. That is, when the first light emitting diode 261 is on and the second light emitting diode 262 is off, the respective article 1 is aligned according to a desired article alignment (see, for example, the left article 1 in FIG. 3 or FIG. 6). Vice versa, when the first light emitting diode 261 is off and the second light emitting diode 262 is on, the respective article 1 is aligned according to an opposite article alignment (see the second article 1 from the left in FIG. 6). Finally, when the first light emitting diode 261 and the second light emitting diode 262 are both off, the respective article 1 does not have a susceptor at all (see the second article 1 from the left in FIG. 7 ) or the respective article location 25 is devoid of an article (see the second article location 25 from the left in FIG. 8 ). Advantageously, the generation of the first and second optical signals allows for easy introduction of the inspection equipment and method into existing manufacturing facilities that already include optical inspection systems.

[0087] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are to be understood in all instances as being modified by the term "about." Also, all ranges include the maximum and minimum points disclosed, and include any intermediate ranges thereof, which may or may not be specifically recited herein. Thus, in this context, the number A is to be understood as A±5%.

Claims

1. 1. A method of inspecting elongated inductively heatable aerosol-generating articles for the presence of a desired article alignment at a particular article location in an article manufacturing facility, wherein a susceptor is provided for inductively heating an aerosol-forming substrate contained within said article, and wherein the arrangement of said susceptor at or within said article is asymmetric relative to a length axis of said article, said method comprising: - detecting the presence or absence of a susceptor at a first test site at the article location using a first sensor, said first sensor being responsive to said susceptor being at least one of conductive, magnetic or magnetized and to the presence of said susceptor at said first test site, said first test site being selected such that said presence of said susceptor at said first test site indicates said presence of said desired article alignment at said article location; - determining the presence of said desired article alignment at said article location if said presence of a susceptor at said first test site is detected.

2. - detecting the presence or absence of a susceptor using a second sensor at a second test site at the article location, the second sensor being responsive to the susceptor being at least one of conductive, magnetic or magnetized and the presence of the susceptor at the second test site being selected such that the presence of the susceptor at the second test site indicates the presence of an opposite article alignment at the article location having a longitudinal extension that is reversed 180 degrees relative to a desired article alignment; - determining the presence of the opposing alignment of articles at the article location when the presence of a susceptor is detected at the second test site, or otherwise determining the absence of an article at the article location or the absence of a susceptor at or within the article when the absence of a susceptor is detected at the first test site and the second test site.

3. 3. The method of claim 1, further comprising the step of generating a first optical signal when the presence of the desired alignment is determined.

4. The method of claim 3, further comprising the step of detecting the first optical signal using one or more optical detectors.

5. The method of any one of claims 1 to 4, wherein the location of the particular item within the item manufacturing facility is one of a pocket of a conveyor or packaging device, or a groove of a conveyor device, or a carrier of a conveyor device.

6. 3. The method of claim 2, wherein the steps of detecting the presence or absence of a susceptor at the first test site and detecting the presence or absence of a susceptor at the second test site are performed simultaneously.

7. 3. The method of claim 2, further comprising the step of magnetizing the susceptor prior to detecting the presence of a susceptor at the first test site and, if implemented, prior to detecting the presence of a susceptor at the second test site.

8. 1. An apparatus for inspecting elongated inductively heatable aerosol-generating articles for the presence of a desired article alignment at a particular article location in an article manufacturing facility, wherein a susceptor is provided for inductively heating an aerosol-forming substrate contained within said article, and wherein an arrangement of said susceptor at or within said article is asymmetric with respect to a length axis of said article, comprising: - an apparatus comprising: a first sensor arranged and configured to detect the presence or absence of a susceptor at a first test site at the article location, the presence of the susceptor at the first test site indicating the presence of the desired article alignment at the article location, the first sensor responsive to the susceptor being in at least one of a conductive, magnetic or magnetized state, and responsive to the presence of the susceptor at the first test site.

9. 10. The apparatus of claim 8, further comprising a second sensor arranged and configured to detect the presence or absence of a susceptor at a second test site at the article location, wherein the presence of the susceptor at the second test site indicates the presence of an opposite article alignment at the article location having a longitudinal extension that is reversed 180 degrees relative to a desired article alignment, the second sensor being responsive to the susceptor being in at least one of a conductive, magnetic, or magnetized state and responsive to the presence of the susceptor at the second test site.

10. 10. The equipment of claim 9, further comprising an electrical circuit operably connected to the first sensor and configured to determine the presence of the desired article alignment at the article location in response to the first sensor detecting the presence of a susceptor at the first test site.

11. 11. The arrangement of any one of claims 9 to 10, wherein at least one of the first sensor or the second sensor comprises one of a reed switch, a Hall effect sensor, an inductive coil, an inductive loop, an LC resonant circuit comprising an inductor and a capacitor, a giant magnetoresistance based sensor, or an anisotropic magnetoresistance based sensor.

12. The apparatus of any one of claims 8 to 11, further comprising a magnetizer arranged and configured to magnetize the susceptor of the article.

13. a first light indicator operably connected to the first sensor or the electrical circuit and configured to provide a first light signal in response to the first sensor detecting the presence of a susceptor at the first test site or in response to the electrical circuit determining the presence of the desired article alignment at the article location; and a second light indicator operably connected to the second sensor or the electrical circuit and configured to provide a second light signal in response to the second sensor detecting the presence of a susceptor at the second test site or in response to the electrical circuit determining the presence of the opposing article alignment at the article location.

14. The facility of claim 13 , further comprising at least one optical detector disposed and configured to detect at least one of the first optical signal or the second optical signal.

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