Patent ID: 12193507

DETAILED DESCRIPTION

We now describe an example of a vapour generating device, including a description of an example induction heating assembly and an example induction heatable cartridge. An example method of monitoring temperature in a vapour generating device is also described.

Referring now toFIG.1andFIG.2, an example vapour generating device is generally illustrated at1in an assembled configuration inFIG.1and an unassembled configuration inFIG.2.

The example vapour generating device1is a hand held device (by which we intend to mean a device that a user is able to hold and support un-aided in a single hand), which has an induction heating assembly10, an induction heatable cartridge20and a mouthpiece30. Vapour is released by the cartridge when it is heated. Accordingly, vapour is generated by using the induction heating assembly to heat the induction heatable cartridge. The vapour is then able to be inhaled by a user at the mouthpiece.

In this example, a user inhales the vapour by drawing air into the device1, through or around the induction heatable cartridge20and out of the mouthpiece30when the cartridge is heated. This is achieved by the cartridge being located in a heating compartment12defined by a portion of the induction heating assembly10, and the compartment being in gaseous connection with an air inlet14formed in the assembly and an air outlet32in the mouthpiece when the device is assembled. This allows air to be drawn through the device by application of negative pressure, which is usually created by a user drawing air from the air outlet.

The cartridge20is a body which includes a vaporisable substance22and an induction heatable susceptor24. In this example the vaporisable substance includes one or more of tobacco, humectant, glycerine and propylene glycol. The susceptor is a plurality of plates that are electrically conducting. In this example, the cartridge also has a layer or membrane26to contain the vaporisable substance and susceptor, with the layer or membrane being air permeable. In other examples the membrane is not present.

As noted above, the induction heating assembly10is used to heat the cartridge20. The assembly includes an induction heating device, in the form of an induction coil16and a power source18. The power source and the induction coil are electrically connected such that electrical power may be selectively transmitted between the two components.

In this example the induction coil16is substantially cylindrical such that the form of the induction heating assembly10is also substantially cylindrical. The heating compartment12is defined radially inward of the induction coil with a base at an axial end of the induction coil and side walls around a radially inner side of the induction coil. The heating compartment is open at an opposing axial end of the induction coil to the base. When the vapour generating device1is assembled, the opening is covered by the mouthpiece30with an opening to the air outlet32being located at the opening of the heating compartment. In the example shown in the figures, the air inlet14has an opening into the heating compartment at the base of the heating compartment.

As mentioned above, in order for vapour to be produced, the cartridge20is heated. This is achieved by an alternating electrical current changed from a direct electrical current supplied by the power source18to the induction coil16. The current flows through the induction coil causing a controlled EM field to be generated in a region near the coil. The EM field generated provides a source for an external susceptor (in this case the susceptor plates of the cartridge) to absorb the EM energy and convert it to heat, thereby achieving induction heating.

In more detail, by power being provided to the induction coil16a current is caused to pass through the induction coil, causing an EM field to be generated. As mentioned above, the current supplied to the induction coil is an alternating (AC) current. This causes heat to be generated within the cartridge because, when the cartridge is located in the heating compartment12, it is intended that the susceptor plates are arranged (substantially) parallel to the radius of the induction coil16as is shown in the figures, or at least have a length component parallel to the radius of the induction coil. Accordingly, when the AC current is supplied to the induction coil while the cartridge is located in the heating compartment, the positioning of the susceptor plates causes eddy currents to be induced in each plate due to coupling of the EM field generated by the induction coil to each susceptor plate. This causes heat to be generated in each plate by induction.

The plates of the cartridge20are in thermal communication with the vaporisable substance22, in this example by direct or indirect contact between each susceptor plate and the vaporisable substance. This means that when the susceptor24is inductively heated by the induction coil16of the induction heating assembly10, heat is transferred from the susceptor24to the vaporisable substance22, to heat the vaporisable substance22and produce a vapour.

The induction coil16is embedded in a wall28. This restricts contact between the induction coil and the environment around the induction coil. In use, heat passes from the heating compartment12into the wall in which the induction coil is embedded, which also provides the side walls to the heating compartment. The induction coil also generates small quantities of heat due to the resistance of the coil.

In order to make use of this heat and to transfer heat away from the induction coil to cool the induction coil, the air inlet14, which, as mentioned above, is connected to the base of the heating compartment, passes from an opening at one end of the induction coil adjacent where the mouthpiece30and the induction heating assembly10meet, past the wall within which the induction coil is embedded to the opposing end of the induction coil, across this end to the opening in the base of the heating compartment. When a user draws air through the air outlet32in the mouthpiece, air is pulled through the air inlet (as indicated by arrow48inFIG.1) into the heating compartment, through the cartridge (should one be present) and through the air outlet (as indicted by arrow50inFIG.1).

When the air in the air inlet14is cooler than the wall28in which the induction coil16is embedded, heat is transferred from the wall (and therefore from the induction coil) to the air. This warms the air and cools the wall and induction coil. The air that passes through the cartridge is therefore warmer than the air outside of the vapour generating device1.

In the example shown inFIGS.1and2, the air inlet14is enclosed by an outer wall34. The outer wall provides a barrier between the air inlet and the exterior of the vapour generating device1. Should the outer wall be warmer than the air in the air inlet, heat is also transferred from the outer wall to the air in the air inlet.

As mentioned above, the air passes into the heating compartment12from the air inlet14as indicated by arrow48. The cartridge20is a close fit with the heating compartment. As such, the air must pass through the cartridge when passing through the heating compartment containing a cartridge. Air flow around the cartridge is therefore restricted and there is no intentional air flow path around the cartridge between the cartridge and the wall28within which the induction coil16is embedded. Since the air passing into the heating compartment has been warmed before it enters the heating compartment and cartridge, it limits the amount of heat lost from the cartridge to the air, which keeps the cartridge warmer.

InFIG.2there is an EM shield36that is embedded in the wall28within which the induction coil16is embedded. The EM shield is located on the radially outer side of the induction coil. When the vapour generating device1is in use, the EM shield will become warm due to the heat produced by the induction coil and in the heating compartment12, and may become warm due to the currents produced in the shield due to the shielding process.

A cross-section along plane A-A ofFIG.2is shown inFIG.3. This shows a circular body, showing that the vapour generating device is generally cylindrical. The heating compartment12is in the centre enclosed by a wall28within which the induction coil16is embedded along with the EM shield36.

As inFIG.2, it can be seen that the EM shield is located around the induction coil on the radially outer side of the coil.

The air vent14is located around the wall28within which the induction coil16and EM shield36are embedded. The air vent is divided into arcs38, each of which provide an air flow path. The air vent is divided by ribs40. The ribs are connected between the wall within which the induction coil and EM shield are embedded and the outer wall34that surrounds the air vent on its radially outer side.

FIG.4shows the same cross-section as shown inFIG.3for an alternative example vapour generating device. The device is accordingly still circular with the heating compartment12located at its centre. The heating compartment is again enclosed by a wall28within which an induction coil16and an EM shield36are embedded in the same configuration as the vapour generating device shown inFIGS.2and3. Instead of arcs forming air flow paths for the air vent, in this example, the air vent14is provided by a plurality of circular bores39, as inFIG.4, distributed evenly in a circle on the radially outer side of the EM shield. Each of the bores provides an air flow path and is separated from the adjacent bores by ribs40that connect the wall within which the coil and EM shield are embedded to the outer wall34, which forms the outer wall of the vapour generating device.

The same cross-section of a further alternative example vapour generating device is shown inFIG.5. The device is again circular with a heating compartment12located at is centre. A wall28surrounds the heating compartment. The induction coil16is embedded within this wall. However, instead of an EM shield also being embedded in this wall as in the example shown inFIG.3, the EM shield36is embedded in the outer wall34. The outer wall is separated from the wall within which the coil is embedded by the air vent14. As with the example shown inFIG.3, the air vent is divided into arcs38, which are separated by ribs40. In this configuration the arcs38may be provided by a metal tube. In this case the metal tube is able to work as susceptor and provide pre-heating of the air entering the heating compartment12. The metal tube may also work as an EM shield.

FIG.6shows a cross-section of another alternative example vapour generating device along the same plane asFIGS.3to5. In this example the device has the same structure as the example ofFIG.5, but instead of being the outer wall, the wall within which the EM shield is embedded is an intermediate wall42. Radially outward from this intermediate wall there is an outer wall34. There is an air vent14between the outer wall and the intermediate wall as well as there being an air vent between the intermediate wall and a wall28within which the induction coil16is embedded and which surrounds a heating compartment12. Each air vent is divided into arcs38by ribs40extending between the respective walls for the respective air vent. Each arc again provides an air flow path.

In the example shown inFIG.6, the air vent14can have one of multiple arrangements. Two such arrangements are shown inFIGS.7and8.

FIG.7shows an arrangement of an example vapour generating device with a cross-section similar to that shown inFIG.6. In the arrangement shown inFIG.7, the vapour generating device has an outer wall34that provides the external wall of the device. Radially inward of the outer wall, there is an intermediate wall42which has a radial separation from the outer wall and a radial separation from a wall28within which an induction coil16is embedded. The wall within which the induction coil is embedded is located radially inward of the intermediate wall, and which provides the side walls of a heating compartment12defined radially inward of this wall.

There is an air vent14that passes from an exterior of the device to the heating compartment. There is a single airflow path running through the air vent, which is indicated at48inFIG.7. The path enters the vapour generating device through the outer wall34at a location in line with an axial end of the heating compartment12. The path then passed between the outer wall and the intermediate wall42to a location in line with an opposing axial end of the heating compartment. At this location there is a passage between the gap provided by the radial separation between the outer and intermediate walls and the gap provided by the radial separation between the intermediate wall and the wall28within which the induction coil16is embedded. The airflow path passes through this passage and returns between the intermediate wall and the wall within which the induction coil is embedded to a location again in line with the initial axial end of the heating compartment, but at a lesser radial separation from the heating compartment than when the path enters the vapour generating device. The path then follows a further passage into the heating compartment at that axial end of the heating compartment.

FIG.8shows an alternative arrangement to that shown inFIG.7of an example vapour generating device with a cross-section similar to that shown inFIG.6. As with the arrangement shown inFIG.7, in the arrangement shown inFIG.8, the vapour generating device has an outer wall34that provides the external wall of the device. Radially inward of the outer wall, there is an intermediate wall42which has a radial separation from the outer wall and a radial separation from a wall28within which an induction coil16is embedded. The wall within which the induction coil is embedded is located radially inward of the intermediate wall, and which provides the side walls of a heating compartment12defined radially inward of this wall.

As withFIG.7, inFIG.8, there is an air vent14that passes from an exterior of the device to the heating compartment. However, instead of the single airflow path48ofFIG.7, the arrangement shown inFIG.8has an airflow path, indicated at50inFIG.8, which has a common beginning and common end, but has two generally parallel sections between the beginning and end. The path enters the vapour generating device through the outer wall34at a location in line with an axial end of the heating compartment12. The path then spits. One section of the path passes between the outer wall and the intermediate wall42in the gap provided by the radial separation of these walls. The other section of the path passes through a passage to the gap provided by the radial separation between the intermediate wall and the wall28within which the induction coil16is embedded. This section of the path then passes through this gap. The two sections re-join at a location in line with an opposing end of the heating compartment12. This is achieved by the section of the path passing between the outer wall and the intermediate wall and then passing through a passage in the intermediate wall at to join the section passing between the intermediate wall and the wall within which the induction coil is embedded to the location equivalent to the opposing axial end of the heating compartment. The path then continues along a common end section into the heating compartment at that axial end of the heating compartment.

As with the example shown inFIG.6, the arrangements shown inFIGS.7and8have ribs (not shown inFIGS.7and8) that connect and support the various walls forming arc sections in the air vent14.

FIGS.9and10each show example air flow paths able to be used in a vapour generation device. Each of these figures shows a cylinder representing the wall28within which the induction coil is embedded.

FIG.9shows an air flow path44, which is provided by the air vent (not shown inFIGS.9and10). The air flow path passes around the wall28in a zig-zag pattern. By this we intend to mean that the path has parallel sections that are aligned with the longitudinal axis of the cylindrical wall and are joined to adjacent sections by curved sections of air flow path at the ends of the parallel sections. In this configuration one or more air flow paths are arranged around the whole wall.

FIG.10shows an air flow path46. This air flow path is again provided by the air vent (not shown). The air flow path passes around the wall28in a spiral passing from one axial end of the wall to the opposing axial end of the wall.