INHALATION DEVICE WITH AT LEAST ONE LIQUID JET DEVICE, CARTRIDGE FOR AN INHALATION DEVICE AND METHOD OF CONVEYING LIQUID DROPS IN AN INHALATION DEVICE

Abstract

An inhalation device (10), in particular an electronic cigarette, has at least one liquid jet device (24), such as a micro heater or resistor, to produce liquid drops on demand, wherein a hollow needle (40) is mounted on the liquid jet device (24). A cartridge (16) has at least one first septum (54) sealing Around the needle (40) of the inhalation device (10). Further, the invention relates to a method of conveying liquid drops in an inhalation device (10) as a liquid jet, such as by means of at least one liquid jet device (24), in particular a micro heater or resistor, in combination with a hollow needle (40) mounted on the liquid jet device (24).

Description

TECHNICAL FIELD

The invention relates to an inhalation device, in particular an electronic cigarette, with at least one liquid jet device, a cartridge for an inhalation device and a method of conveying liquid drops in an inhalation device.

In recent years, inhalation devices such as e-cigarettes have become popular as a replacement for conventional smoking articles. In this context, a certain amount of liquid has to be stored in the inhalation device, preferably in a replaceable cartridge and has to be delivered appropriately to a heater so as to form an aerosol.

PRIOR ART

US 2020 0308107 A1 is related to such a smoking article comprising a reservoir containing an aerosol precursor composition being in fluid communication with a microheater.

A similar vaporizer is derivable from U.S. Ser. No. 10/314,342 B2.

GB 2542921 B discloses a vaporizer having a micro pump. A cartridge containing liquid can be inserted into the vaporizer and has a rubber septum which is punctured by a needle.

Finally, a similar vaporizer is known from U.S. Ser. No. 10/285,449 B2.

SUMMARY OF THE INVENTION

In view of the above, there remains a need for an improved inhalation device, in particular an electronic cigarette, which can provide an appropriate production of aerosol.

This is achieved by means of the inhalation device, in particular the electronic cigarette, in accordance with claim 1, which has at least one liquid jet device and a hollow needle mounted thereto.

In general, the inhalation device of the present disclosure may be an electronic cigarette.

Thus, the inhalation device essentially uses drop-on demand technology similar to inkjet printers. In other words, liquid drops to be delivered so as to form an aerosol are produced on demand. In this context, an appropriate interface between a liquid container, typically in the form of a replaceable cartridge insertable into the inhalation device, needs to be provided. This is, according to the invention, achieved by means of a hollow needle mounted on the liquid jet device. The hollow needle is, as described in more detail below, adapted to puncture a septum closing the cartridge in an original state and will then reliably deliver liquid to the liquid jet device of the inhalation device.

In this context, a volume between the cartridge and the drop outlet, i.e. the location, where the drop is delivered to the liquid jet device, can advantageously be minimized, so that contamination can be significantly reduced. In particular, sometimes different fluids or liquids are used in an inhalation device in succession, and it is then desirable to quickly change from one liquid to the other. This is advantageously supported by the structure in accordance with the invention, in which the described volume between the cartridge and the drop outlet is minimized.

Moreover, by means of the hollow needle adapted to puncture a septum and extending into the liquid contained in the cartridge, undesirable introduction of air into the fluidic path can be avoided. Moreover, when no cartridge is present, for example, due to the fact that it is being replaced, leaking of fluid from the device can be minimized by means of the hollow needle, which will retain liquid due to capillary forces. At the same time, air cannot enter the fluidic path, even when the cartridge is just to be inserted into the device.

Preferred embodiments are described in the further claims.

As regards the liquid jet device, providing same as an MEMS (Micro-Electro-Mechanical System) has proven efficient, as such a technology is well established for drop on demand technology.

In order to cover the (sharp) point of the hollow needle so as to avoid injuries of the user, for example, when inserting a new cartridge, a spring-loaded plate can advantageously be provided so as to surround the needle in a manner to extend beyond the needle point, when the spring element is at least partly relaxed. Thus, the needle point is protected from being touched, when no cartridge is present, and is pushed back so as to expose the needle point and allow it to puncture a septum of the cartridge.

The described function of the spring-loaded plates which involves a certain movement of the same, can be made particularly reliable, when the inhalation device and/or the plate has means for positioning the spring element biasing the plate.

This is further supported by the optional feature that the needle is adapted to guide the spring-loaded plate.

As already indicated above, the invention is also related to a cartridge for an inhalation device with at least one liquid jet device and a hollow needle, the cartridge having at least two septa, at least one of them having a hole adapted to tightly seal around the needle of the inhalation device. In this manner, leakage of fluid is prevented also in a state, in which the other septum typically closing the cartridge prior to its use, has been punctured by the hollow needle. Further, in order to provide a ready to use inhalation device, the cartridge can advantageously be combined with the inhalation device.

The combination of the at least two septa provides a leak free cartridge in its detached state, i.e. when the cartridge is not combined with the inhalation device. When the needle punctures the at least two septa, a liquid tight seal is obtained with minimal force, allowing fluid to pass through the needle without exiting the septa seal. This is particularly important in the cartridge as a detached cartridge is likely to be carried in any orientation with significant shock type deceleration during handling. In conventional liquid jet type systems, the cartridge has a one-time seal that is removed prior to use. In the cartridge according to the present invention a user may insert and then remove the cartridge multiple times if they desire to change the flavor, for example. The combination of the at least two septa provides a reusable seal.

In particular, the one septum may be provided with the hole adapted to tightly seal around the needle of the inhalation device and the other septum may be provided with a slit that is adapted to tightly seal the other septum to thereby completely close the cartridge, when the needle is not present, i.e. when the cartridge is not combined with the inhalation device. With this configuration, the one septum creates a tight seal around the needle, when the needle is inserted. When the needle is not present, the hole provided in the one septum remains open. Further, the other septum is tightly sealed, when the needle is not present. When the needle is inserted, the slit provided in the other septum does not tightly seal around the needle. Accordingly, with this dual-septa configuration, the cartridge is tightly sealed both in a state when the needle is present and in a state when the needle is not present, i.e. inserted. Accordingly, leakage of fluid is prevented in both states.

The septum may be made of a bio-compatible material. The septum is not the primary fluid path but it is possible for the septum to contact the fluid and then have the fluid delivered to the liquid jet device. Preferably, the septum is made of PTFE/Rubber (butyl) type material. However, natural rubber, silicone, or polyvinylchloride are other viable options.

The cartridge can in particular have the container and at least one a cap, to which a capillary tube can be attached. Thus, after filling the container it can be closed, and the capillary tube together with an optional absorbing element, such as a wick can be brought in place in a single step. The cap is preferably connected to the container by means of a thread, and at least one seal can be provided between the cap and the container in order to avoid fluid leakage between the two.

The at least one seal is provided between the container and the (threaded) cap. A threaded cap is unusual in that it can provide a reusable seal for keeping fluid in the cartridge and keeping contamination out of the container. The seal, which may be made of a rubber material, can deform to provide an improved connection between the threaded cap and the container.

The capillary tube, which can also be called an internal tube typically extends from a delivery outlet, and the capillary tube and/or the absorbing element extend substantially to the bottom of the container opposite the delivery outlet.

In this manner, two opposing forces are taken into account and balanced in order to provide the appropriate flow of liquid, i.e. enough liquid to allow appropriate aerosol generation in any orientation of the device, and not too much liquid, in order to avoid “drooling” of liquid. This is essentially achieved by generating capillary forces in combination with gravity to create sufficient forces to pull or draw liquid from the reservoir to the liquid jet device, in particular a microheater or a resistor. At the same time, in any orientation of the device, enough negative pressure is created, which “sucks” the liquid into the container functioning as a reservoir in order to avoid too much liquid being expelled from the device. Moreover, the invention serves to provide fluid damping to the liquid delivery system, so that essentially all liquid in the reservoir can be delivered, before air enters the liquid path, which would cause a deprime.

In detail, the capillary tube, which can also be called a pickup tube or dip tube extends from the delivery outlet of the container and essentially draws liquid towards the delivery outlet, when the device is oriented with the delivery outlet essentially at the top. The absorbing element is combined with the capillary tube and provides enough back pressure to avoid too much liquid to be delivered to the liquid device, even when the device is oriented with the delivery outlet downwards. In addition, the absorbing element, which can for example be a piece of foam or a wick, absorbs a certain amount of liquid and retains this to provide a kind of damper, so that even in case of a rapid movement or “sloshing” of the container, air does not enter the liquid delivery system. As a damper the wick provides a steady state continuous fluid to the liquid jet device. Its capillary structures allow for consistent fill rates and pressure for the fluid supply. Further, the liquid retained in the capillary tube and the absorbing element allows the device to function for some time, even when the delivery outlet is oriented downwards and the level of liquid is too low to allow the capillary tube or the absorbing element to contact the liquid. That is, the absorbing element, such as the wick, acting as a temporary supply of fluid, absorbs a few puffs worth of fluid. If an inhalation device (and its corresponding cartridge/liquid supply) is moved in certain orientations during use, the liquid supply may not be in continuous contact with the liquid jet. The wick allows for fluid to be absorbed in certain orientations and then dispenses fluid in any orientation. The movement of the fluid within the device/container can keep the wick supplied with fluid, in turn supplying the liquid jet during use in non-standard orientations. Finally, the described system can be produced in a cost-efficient manner and, as described, provides a reliable delivery of liquid to a liquid jet device in any orientation of the inhalation device.

The absorbing element can for example be inserted at the end of the capillary tube opposite the delivery outlet. The capillary tube can work in conjunction with the absorbing element, preferably the wick. By putting the wick at the end of the capillary tube, the wick can absorb and deliver fluid to the capillary tube. The capillary tube is volumetrically more efficient than the wick. Using both the wick and the capillary tube, a larger volume of fluid can be stored for non-standard orientation use of the device when compared with a similarly sized wick-only system. As regards materials for the absorbing element, the wick can be formed of cigarette filter material. The liquid jet device as described herein essentially corresponds to an inkjet device commonly used in printers.

As already indicated, as soon as about 30% or more of the liquid in the container has been used, there can be a situation, depending on the length of the combination of the capillary tube and the absorbing element, in which neither one of these contacts the liquid, when the device is held in an orientation with the delivery outlet downwards. Also in such a situation, it is desirable that the device continues to work for a certain period of time, and it is, therefore, preferred that a volume of the capillary tube corresponds to two or three puffs (two or three puffs correspond to 10 μL or 15 μL, respectively). In other words, even in the described orientation, the user can vape for two or three puffs, before the capillary tube is empty, and the orientation of the device has to be changed, in order to fill the capillary tube with liquid.

As regards the inner diameter of the capillary tube in order to ensure the reliable delivery of liquid, an inner diameter of 1 to 3 mm has proven efficient. Beyond 3 mm and in particular towards 4 mm, capillary action cannot be ensured any longer, in particular when using liquids with a low surface tension. On the other hand, with an inner diameter below 1 mm, the inner volume of the capillary tube becomes very small, the flow rate decreases and the delivery of liquid is stopped too quickly.

As regards dimensions of the capillary tube and the absorbing element, any combinations are possible. For example, the capillary tube can be between 5 and 30 mm, and the same applies to the length of the absorbing element. In other words, a very short capillary tube, for example having a length of only 5 mm, can be combined with a very long absorbing element, such as a wick, having a length of for example 3 cm. Such a combination has turned out to work as well as an absorbing element being only 3 mm long and inserted into a capillary tube being for example 3 cm long. Nevertheless, in view of a beneficial combination of total volume and delivered liquid, it is preferably that the capillary tube is longer than the absorbing element. In particular, a combination of an about 3 cm long capillary tube, having an inner diameter of up to 3 mm, with an absorbing element of only about 3 mm length inserted, is currently preferred. A comparably small absorbing element also has the advantage of keeping the retention force on the liquid low and keeping the flow rate high.

As already indicated, a particularly simple structure can be achieved, when the absorbing element is attached to and preferably inserted into a bottom side end of the capillary tube, in other words, the end opposite of the delivery outlet.

Good results have also been achieved with a connecting tube having an inner diameter at least as large as an outer diameter of the capillary tube and the absorbing element, the connecting tube being placed radially outwards the capillary tube and the absorbing element and connecting these.

As also indicated above, it provides benefit to the user, when the combination of the capillary tube and the absorbing element is adapted to deliver liquid to the delivery outlet, also when the delivery outlet is oriented vertically above the bottom of the container.

At the same time, it is preferred that liquid is retained, when the delivery outlet is oriented vertically below the bottom of the content, i.e. the device is held with the delivery outlet oriented downwards.

As regards the material of the capillary tube, Teflon, Polypropylene and Polyethylene have proven efficient and can also be combined for production of the capillary tube.

The desired capillary forces when using the mentioned materials can particularly be achieved, when the liquid is for example a polypropylene glycol/vegetable glycerine mixture or an oil-based perfume, which are common liquids for inhalation devices or aerosol generating devices.

In order to further increase the amount of liquid and the user benefit, at least two containers as described above can be combined so as to form a cartridge insertable into the inhalation device.

Generally, with regard to any details of the cartridge, the disclosure of the applicant's application entitled “Container for an inhalation device with at least one liquid jet device, . . . ” filed on the same day is incorporated herein by means of the reference.

Correspondingly, the invention also provides a method of conveying liquid in an inhalation device as a liquid jet and by means of a hollow needle. This is preferably effected from at least one replaceable container or cartridge.

As already indicated above, the cartridge can have two septa, one of which can be opened, in particular punctured, preferably via a slit provided therein, when inserting the cartridge into the inhalation device, and the other one can be combined with a hollow needle extending into the cartridge so as to form fluid tight seal.

Generally, any features described herein with reference to the inhalation device or cartridge can be applied to the method and vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter, the invention is further described with reference to the drawings, in which:

FIG. 1 shows a perspective view of the inhalation device;

FIG. 2 shows a cut view of essential parts of the inhalation device of FIG. 1;

FIG. 3 shows a cut view of a part of the inhalation device of FIG. 1 with a part of one container;

FIG. 4 shows a cut view of the details of FIG. 3, without any container;

FIG. 5 shows a cut view of a part of a container;

FIG. 6 shows two liquid jet devices in greater detail.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

As can be taken from FIG. 1, the inhalation device 10 as described herein, is essentially elongate with a mouthpiece 12 at one end and charging contacts 14 at the other end. Any aerosol delivered to the mouthpiece 12 is produced from liquid contained in a cartridge 16, which is essentially accommodated in that half of the inhalation device 10, which is closer to the mouthpiece 12. In the case shown, the cartridge 16 is accommodated in a compartment which can be closed by a lid 18, and a longitudinal axis of the device 10 corresponds to a longitudinal axis of the cartridge 16 and containers forming same as described in more detail below.

As can better be seen in FIG. 2, aerosol 20 is produced by in the present case two liquid jet devices 24, which are provided on a PCA or daughter board 26 with a filter 28 between the liquid delivery system described in more detail below and each liquid jet device 24. As can be seen in the lower part of FIG. 2, the cartridge in this case contains two containers 30, which are substantially structured identically, so that only one of them will be described in more detail below. In an upper part of the container 30 it essentially has a cap 32, which can be screwed onto the reservoir part 34 by means of a thread 36. In the present case, the cap 32 has at least one septum 38, which can be punctured by a hollow needle 40 which is part of the inhalation device 10 in accordance with FIG. 2. For this purpose, the at least one septum 38 may be provided with a slit. Anything below needle 40 in FIG. 2 belongs to the cartridge 16, which is replaceable. In the embodiment shown, a capillary tube 42 is attached to the cap 32 and is adapted to deliver liquid towards the delivery outlet at the top of the cartridge 16 in accordance with the orientation of FIG. 2. The delivery direction of the liquid is indicated by arrows.

In the embodiment shown, a connecting tube 44 is attached outside the capillary tube 42 and an absorbing element 46 is attached inside the connecting tube 44. In the case shown, there is a certain gap between the capillary tube 42 and the absorbing element 46, but this gap does not necessarily have to be present and can also be greater than shown. As can also be taken from FIG. 2, the absorbing element 46, such as a wick, extends substantially to the bottom of the container 30, so that in the orientation of FIG. 2, essentially all of the liquid contained can be drawn towards the delivery outlet. In the embodiment shown, both caps 32 are essentially circle cylindrical, and this also applies to the reservoir parts 34, which are connected with each other. The inner volume of the reservoir part 34 is also essentially circle cylindrical, in the embodiment shown with a cone shaped lower part. Further, in the embodiment shown, a suitable air path 48 is provided between the capillary tube 42 and the inner surface of the reservoir part 34 in the area of the thread 36 so as to allow air to enter the reservoir part and to avoid the build-up of excessive negative pressure. Further, in the embodiments shown, an O-ring 50 is provided between the reservoir part 34 and the cap 32 as a gasket.

FIG. 3 essentially shows the situation of FIG. 2 with a single container, in particular, only the cap 32 and the O-ring 50 thereof are shown in the upper part of FIG. 3. Although usually two containers 30 are combined to form a cartridge 16 as shown in FIG. 2, the lower container is not shown in FIG. 3 in order to show a spring-loaded plate 52 in more detail. As shown in FIG. 3, when a container is inserted, and the hollow needle 14 has punctured a septum 38, preferably via a slit provided therein, which originally seals the container, in order to allow the removal of liquid therefrom, the spring-loaded plate 52 has been pushed, against the action of a spring 56.

However, as shown in FIG. 4, in a state, where no container is inserted, the spring 56 acts to push the plate 52 far enough towards the right side in FIG. 4, that the point of the hollow needle 40 is covered, in order to avoid injuries. This position of the plate 52 is defined by a step 58 in the cavity for accommodating the container. Moreover, in the case shown, an inner cylindrical cavity 60 of the plate 52, which is in the case shown also formed in a hub 62 extending a significantly longer distance along the hollow needle 40 than the relatively thin plate 52, serves to cooperate with the hollow needle 40 in order to provide some guiding of the plate 52 along the movement direction (from left to right and vice versa in FIGS. 3 and 4). Moreover, the outer dimension of the plate 52 is chosen so as to be movably accommodated and to some extent guided in the cavity surrounding the movable plate 52.

The position of the spring-loaded plate 52 farthest to the left as shown in FIG. 3 is defined by the hub 62 abutting the base 64, from which the hollow needle 40 extends. As can particularly be taken from FIG. 4, the outside diameter of hub 62, which can also be considered a kind of rod, is appropriately sized to align and guide the spiral spring 56 at the right part according to FIGS. 3 and 4. Towards the delivery outlet, the same function is achieved by a circular collar 66 guiding the spring 56 from the outside thereof.

FIG. 5 again shows the cap 32 and O-ring 50 of a container similar to the details of FIG. 3, as well as the capillary tube 42 thereof. Moreover, two septa, septum 38 sealing the container in the original, non-used state, and a septum 54 sealing around the hollow needle 40 when inserted, are shown in more detail. In particular, both of these are essentially circular, the septum 38 to be punctured by the hollow needle 40 is located closer towards the capillary tube 42 and placed on a step 68, and on top of the upper septum 54 there is a retaining ring 70 partly accommodated in a groove 72, in order to secure the septa. In accordance with the orientation of FIG. 5 below the septa 38, 54, there is another stop 74 for defining the position of the capillary tube 42, along the axial extension thereof. The septum 38 may be provided with a slit, having the features as described above.

FIG. 6 represents in a cross-sectional diagram a portion of an example of an inhalation or aerosol-generation device.

The combination of two liquid devices 24 comprises here two microfluidic structures or MEMS dies 150. Each MEMS die 150 has an upper surface or vaporization surface 151.

The liquid devices 24 are in fluid communication with two liquid channels 140 each of which is arranged to deliver the liquid aerosolizable material from the reservoir part 34. Each liquid channel 140 is connected to an MEMS die 150 through an inlet port 152. Liquid aerosolizable material is drawn from each liquid channel 140 to a MEMS die 150 by capillary force.

Two aerosol flow paths 153 are arranged to fluidly communicate with the mouthpiece of the aerosol-generating device. Each aerosol flow path 153 allows thus the generated aerosol to flow from a MEMS die 150 to the mouthpiece. In other words, the airflow paths 153 connect air inlets (not shown) within the aerosol-generating device to the mouthpiece for the passage of air through the aerosol-generating device.

A downstream end of each aerosol flow path 153 forms a nozzle 154. The nozzles 154 and the vaporization surfaces 151 are usually on parallel planes. In other words, each nozzle 154 faces a vaporization surface 151.

Each nozzle 154 can be offset from the vaporization surface 151 or alternatively, the nozzle 154 and the vaporization surface 151 may align in direction one above the other.

When a user draws on the mouthpiece, air is brought into the airflow paths 153 through the air inlets connected to the airflow paths 153 so as to create a pressure change that draws the generated aerosol flow to the mouthpiece as it passes over the vaporization surface 151.

In a setup where each nozzle 154 is offset from a corresponding vaporization surface 151, incoming air through the air inlets can flow sideways along the vaporization surface 151 and is then pulled up by the nozzle 154. Alternatively, incoming air through the air inlets can flow directly into the airflow path 153 over the vaporization surface 151. The nozzle 154 is jetting either perpendicular to, or in parallel with the airflow of the mouthpiece.

Claims

1. An inhalation device (10), in particular an electronic cigarette, with at least one liquid jet device (24), such as a micro heater or resistor, to produce liquid drops on demand, the inhalation device (10) being suitable for being combined with a cartridge (16), wherein a hollow needle (40) is mounted on the liquid jet device (24), the hollow needle (40) being adapted to puncture a septum closing the cartridge (16), when the cartridge (16) is combined with the inhalation device (10).

2. The inhalation device (10) of claim 1, wherein the liquid jet device (24) is in the form of an MEMS.

3. The inhalation device (10) of claim 1 or 2, further comprising a spring-loaded plate (52) surrounding the needle in a manner to extend beyond a needle point, when the spring element is at least partly relaxed.

4. The inhalation device (10) of one of the preceding claims, wherein the inhalation device (10) and/or the spring-loaded plate (52) has means (66, 62) for positioning the spring element.

5. The inhalation device (10) of one of claim 3 or 4, wherein the needle is adapted to guide the spring-loaded plate (52).

6. A cartridge (16) for an inhalation device (10) with at least one liquid jet device (24) and a hollow needle (40), preferably combined with the liquid jet device (24) of one of the proceeding claims, with at least two septa (38, 54), at least one (54) of them having a hole adapted to tightly seal around the needle (40) of the inhalation device (10).

7. The cartridge (16) of claim 6 further comprising a first septum (38) sealing the cartridge (16) in an original state.

8. The cartridge (16) of claim 6 or 7 wherein the cartridge (16) has a container (30) and at least one cap (32), preferably connected to the container (30) by a thread (36).

9. The cartridge (16) of claim 8 further comprising at least one seal (50) between the cap (32) and the container (30).

10. The cartridge (16) of one of claims 6-9, further comprising at least one wick (46).

11. The cartridge (16) of one of claims 6-10, further comprising at least one internal tube (44).

12. A method of conveying liquid drops in an inhalation device (10), the inhalation device (10) being suitable for being combined with a cartridge (16), as a liquid jet, such as by means of at least one liquid jet device, in particular a micro heater or resistor, in combination with a hollow needle (40) mounted on the liquid jet device (24), the hollow needle (40) being adapted to puncture a septum closing the cartridge (16), when the cartridge is combined with the inhalation device (10).

13. The method of claim 12, wherein the liquid is delivered to the liquid jet device (24) from at least one replaceable cartridge (16).

14. The method of claim 13, wherein when combining the inhalation device (10) and the cartridge (16), a first septum (38) of the cartridge (16) is opened, and a second septum (54) of the cartridge (16) is combined with a hollow needle (40) of the inhalation device (10) in a fluid tight manner.