Patent Application
20210386945
The present invention relates to inhaler devices, in particular to devices provided with medicament carriers containing individual pockets or blisters of powdered medicament covered by a lidding sheet such as a lidding foil.
Delivery of drugs in aerosol form to the airways using an inhalation device is a well-known and effective method of treating diseases such as asthma and Chronic Obstructive Pulmonary Disease (COPD). The aerosol can either be in liquid or powder form.
Dry powder devices often use the patient's inhalation air flow to aerosolize and deliver the dry powder drug. One benefit of this is that a user need not coordinate inspiration with another action, for example depressing a canister or pressing a button to release a propellant.
Various different types of dry powder inhaler are known.
A first group of devices holds the powdered drug in a reservoir and meters the dose prior to delivery. These devices often suffer from poor accuracy of dose metering and it can be difficult to protect the bulk powder from moisture.
Also known are pre-metered dry powder devices, in which accurate dose metering is carried out as part of the manufacturing process and each dose is independently protected from moisture.
The individual doses used in pre-metered devices are typically held in either a gelatine capsule or a foil blister. Capsule based inhaler devices can be simple and low-cost, but typically require the patient to load the inhaler with a capsule prior to each use. The environmental protection provided by the capsule is also not particularly effective. This generally necessitates the use of secondary, foil-based packaging, adding to the number and awkwardness of the steps in the use-sequence.
Blister devices tend to provide better environmental protection due to the aluminium foil used in their construction. They can also be more convenient for users, because a blister pack can contain several doses, ideally enough for a month's usage.
Since most current drugs for asthma or COPD are used once or twice a day, this means an inhaler should be able to contain 30 or 60 doses. To enable these doses to be packaged into a conveniently sized device, the blisters may be configured into a disk form or an elongate strip form. The individual blisters need to be opened before inhalation takes place, so that when the patient inhales the powdered drug is entrained in the patient's inspiratory airflow and carried out of the device into the patient's lungs. Before, after, or during each inhalation, the pack must be also indexed by one blister so that the previously emptied blister is replaced by a fresh blister.
Various means of opening blisters and indexing are known from the prior art.
U.S. Pat. No. 4,627,432 describes an inhaler device that uses a blister pack in disk form. The doses are arranged in a circular pattern, with each disk containing 8 blisters. A plunger is used to pierce each blister and enable the drug therein to be inhaled. A separate indexing mechanism rotates the disk to move a fresh blister into place.
Although mechanically simple, a problem with this device is that the number of doses is limited to eight in order to keep the device small in size and simple in operation. Configuring a disk-based device to contain 30 or 60 doses and still be of acceptable size requires modification of the pocket-shape, or a significantly more complicated device with either multiple disks, or dose cavities formed in (for example) concentric rings or a spiral pattern.
This problem can be partially addressed by providing a similar device with blisters in an elongate strip form. The elongate strip can be coiled within an inhaler device to minimise the necessary packaging space. Separate indexing and piercing mechanisms can be provided, or a single actuating lever may be provided to first index the blister-strip and then pierce the blister, preparing it for inhalation.
A drawback that applies to blister-strip devices such as described so far, is that the action of piercing a blister tends to involve a piercing element that occupies and partially obstructs the blister. As a result, pierceable blisters typically need to be 2 or 3 times larger than the required dose volume in order to provide space for the piercer and to allow the drug to move freely and be entrained in the airflow.
An alternative approach is to use a blister-strip with a peelable lid, the inhaler device peeling the lid of each blister in turn prior to each inhalation. The mechanism for such inhalers is typically more complex, since it needs to manage both the used base sheet/foil and the used lid sheet or lidding foil. However, because no piercer is entering the blister, and because the lid is removed completely, the blister need only be big enough to contain the powdered drug. Smaller blisters can therefore be used for a given dose size.
A well-known peelable strip device is shown in U.S. Pat. No. 5,590,645. The device contains a coil of sealed blisters, a coil of used base sheet and a separate coil of used lid sheet. The base and lid sheets are separated at an opening station, where the lid is peeled back from the base as the strip is indexed. Thus, all three coils move simultaneously. The main strip driver is a drum incorporating recesses that engage with the blisters in the base sheet, while the base and lid sheet coils are also driven to ensure that the used strips are coiled after use. The used base sheet/foil is loosely wound, while the used lid sheet is tightly coiled such that the tension needed to ensure separation from the base sheet is maintained.
A variant of this device that incorporates two blister-strips indexed and opened in the same way is shown in U.S. Pat. No. 8,511,304B. The two strips are arranged so that when opened two fresh blisters lie either side of a single airway manifold. Thus, the contents of both blisters can be inhaled simultaneously. The potential advantage of this is that two separate drugs or drug combinations can be stored in separate blisters yet inhaled together.
One significant use error that can occur in peelable strip devices arises from the blisters being opened as the strip is indexed, rather than in a separate action as with most pierceable blister devices. Typically, the user-input in such devices is linked directly to a set of components that simultaneously index and peel the strip to present an open blister-pocket up to the airway for the user to inhale. As a result, blister opening can occur when the actuating mechanism is only partially moved. This is a particular problem in devices where the actuating mechanism is driven by a mouthpiece cover of the device rather than by a separate actuation lever. If the patient part opens the cover, for example to inspect or clean the mouthpiece, then the blister may be partially or completely opened thus exposing the blister contents to environmental moisture. A user may then return the mouthpiece cover to its unopened position without being aware of the potential degradation of the now-exposed formulation. Subsequent complete opening of the cover and inhalation risks inhalation of a compromised dose. Even if a user becomes aware of the premature opening of a blister and rejects the associated dose, the dose will be wasted.
The problem can be mitigated by providing an inhaler with a breath-actuation mechanism so that actuation of a lever or mouthpiece cover indexes a blister strip, but individual blisters are only opened on inhalation be a user. U.S. Pat. No. 7,434,579, for example, discloses a device with a strip comprising a base sheet and lid sheet permanently sealed to each other, and a further tear sheet glued to the lid sheet locally above each blister cavity such that it is able to tear a portion of the lid sheet away from the rest of the blister. When the device is actuated the blister-strip is indexed but no tension is applied to the lid tear sheet until a breath-actuated trigger releases a spring that drives the lid tear sheet coiling mechanism. Although effective, the inclusion of a breath-actuation mechanism adds significant complexity to the inhaler device, and the tear-strip feature is non-standard in blister strip manufacture.
One alternative approach, as discussed in U.S. Pat. No. 8,746,242B, is to provide a delayed actuation mechanism, ie a mechanism where initial movement of a mouthpiece cover does not actuate the indexing and opening mechanism. By delaying the actuation, the likelihood of accidental actuation is reduced. However, it is still possible for an incomplete opening of the cover to partially actuate the device.
There is therefore a need for an improved inhaler device, suitable for use with one or more medicament carriers, that has a simple means of enabling the actuating lever or cover to be moved by the patient without accidentally opening blisters to expose the medicament. Ideally the lever or cover should be reversibly movable through most of its travel, with the point at which blister opening happens being close to the end of the actuation movement and clearly identifiable by the patient.
It is an aim of the present invention to provide such an inhaler device, which mitigates or overcomes some or all of the abovementioned problems while ideally being suitable for use with conventional medicament carriers such as standard blister strips.
According to a first aspect of the invention there is provided an inhaler device as defined in the appended claim 1. Further optional features are recited in the associated dependent claims.
A further aspect of the invention provides an inhaler device as defined in the appended claim 31. Further optional features are recited in the associated dependent claims.
The invention disconnects, or at least partially separates, the indexing and peeling operations during use of an inhaler device. For example, it allows the start of indexing and the start of peeling to occur at different times, and/or it allows one or more particular points in the peeling operation(s) (for example, a point at which the dose or doses are considered to be compromised, such as the point when the dose-pocket(s) begins to open) to be delayed until a more desirable point in the actuation of the device, without the indexing operation(s) necessarily being similarly delayed.
The user's input to the device, for example closing and/or opening the cap or operating a lever/button, can be used to first initiate indexing of the medicament carrier(s), and then to initiate peeling of the lidding sheet/foil(s) from individual blister(s) to present the formulation to the airway.
The invention therefore allows the user to open the device up to a desirable ‘commitment’ point without initiating peeling of the lidding sheet/foil(s), or at least without exposing a blister-pocket of formulation. This means that there is less chance of wasted doses, and less chance of inhalation of degraded formulation.
The commitment point will generally be arranged at or near the end of actuator operation, for example at or adjacent the end of motion during mouthpiece opening. However, it may be provided at any point after the indexing operation has commenced. For example, the operation of peeling open an individual blister of a medicament carrier may coincide or overlap with a portion of the indexing operation.
There are known devices that use a series of geared components to deliver Active Pharmaceutical Ingredient (API) from two distinct blister-strips.
A simple mechanical solution when designing a strip-based device of this type, is to link the user input (usually either a lever/button, or the cap of the device) directly to a set of components that simultaneously index and peel the blister strip. The individual doses or blisters in one or more blister strips are thereby peeled and presented to a single/common airway for the user to inhale.
One common flaw with this system is that part-opening the cap (or part-depressing the lever/button) will partially advance a dose, and partially or fully open the associated blister-pocket. Release or return of the actuator can then cause the blister to be returned to its ‘unpeeled’ position, or left in the position that it has reached, without the user being informed of the potential degradation of the now-exposed formulation.
This problem could be solved by charging a spring and releasing it at the end of cap-open or lever operation, simultaneously effecting indexing and peeling of the strip. However, this requires a very strong spring, not least because the force required to index a strip will be potentially variable if it snags within the device. This increases the required input force, and negatively impacts on user ‘feel’ or feedback during use of the device.
Another known solution is to delay the initiation of the operation (index and peel) until partway through the cap-open/actuation sequence. However, this reduces the range of motion across which the user can input the required energy to the system (the user must input all of the required energy in a single section of cap-opening or lever-operation), which causes similar problems to the incorporation of a strong spring as discussed above.
In the system according to the present invention, a relevant part of the operation of peeling, for example the part or phase of the operation that exposes a dose ready for inhalation, can be delayed relative to the initiation of an indexing operation . In more general terms, at least part of the operation of peeling is delayed relative to the equivalent part of the indexing operation. For example, the initiation of peeling may be delayed relative to the initiation of indexing, and/or the point at which the peeling operation has been progressed by 30% may be delayed relative to the point at which the indexing operation has been progressed by 30%, etc. The point at which a dose is exposed may be delayed until the latest possible moment during cap-open or operation of an alternative actuator.
With conventional systems, indexing and peeling can only be achieved simultaneously. The operations of peeling and indexing are mechanically linked so that their progression is substantially proportional, and delaying one with respect to the other as described above is impossible. By dissociating or separating the two actions, disproportional movement of the indexing and peeling components/systems becomes possible from a single actuator. The benefits of a delayed peel operation can thus be combined with a smoother user experience and improved feedback, because indexing of the device can still take place across the entire operation of an actuator.
Significant development work was required to provide solutions to the problem of delaying at least the part of the ‘peel’ operation that opens or exposes a dose for inhalation, and uncoupling or dissociating this from the indexing of the inhaler device. The solutions can be broadly categorised as one of two main approaches: either regulation—i.e. absence or reduction, to some degree—of tension in the lidding sheet at the peel-front below the level of tension required for peeling, or maintenance of peel-front position relative to the medicament carrier through the use of a moving ‘peel-beak’.
This involves initially indexing the medicament carrier under a position that the airway occupies during inhalation, with the peel-front (i.e. the location at which a lidding sheet or foil is removed from the medicament carrier) substantially moving with the next unopened blister of the medicament carrier. For example, the peeled lidding sheet may be folded back on top of the unopened blister(s) in the medicament carrier during initial indexing. A lidding sheet take-up system is then actuated or allowed to apply tension at the specified point in the operation of the actuator, peeling the lidding sheet under the airway and exposing the open blister to the airway.
Because there is nothing actively maintaining the position of the peel front (the line of peeling separation) in this embodiment, the tension on the lidding sheet should not be applied, or should be released, or ‘backed off’, during the indexing operation to ensure that peeling does not occur until the desired moment.
Moving Peel-Beak
This option involves the use of a specific component (per medicament carrier) that substantially travels with the medicament carrier, keeping the peel-front substantially stationary relative to the medicament carrier during indexing. This moving/movable peel-beak then moves relative to the medicament carrier, at a desirable point, allowing peeling/opening of a desired number of blisters/pockets. For example, the peel-beak may be released, allowing tension in the lidding sheet to pull it back and thus effect peeling.
In some instances, including a moving peel-beak can create an associated problem that may need to be addressed. The space that the peel-beak must sweep through can result in a gap being provided between the newly-peeled blister and the airway. This can be solved in a variety of ways, including, but not limited to:
The peel-beak movement and the movement of the indexing component may be linked by a single component or mechanism, or may be driven simultaneously.
Both the peeling under the inhalation position of the airway option and the moving peel-beak option generally require that the lidding sheet take-up system is capable of allowing the peel-front to substantially move with the medicament carrier.
One way of achieving this is to situate the lidding sheet take-up system in a place where the distances between the take-up system and the start and end position of the peel-front (during peeling) are substantially the same. For example, the take-up system could be situated on (or near) the perpendicular bisecting line of the peel-front's movement. Similarly, this effect could be achieved by situating the lidding sheet take-up system in a place where the distance between the take-up system and the start position of the peel-front (at the commencement of peeling) is greater than the distance between the take-up system and the end position of the peel-front (at the conclusion of peeling). For example, the take-up system could be situated past (ie on the opposite side to the peel-front's start-position) a line that is both perpendicular to a line struck through the peel front's start position and end position, and struck through the peel-front's end position, it will only be required to operate (ie take up lidding sheet/foil) uni-directionally.
An alternative approach is to design the lidding sheet take-up system to be capable of ‘releasing’ some lidding sheet, for example one index-length of lidding sheet (the length of lidding sheet/foil associated with a single index step or dose). This requires the extra take-up of this released length of lidding sheet when the peeling event occurs, for example a length of lidding sheet equal to two index-lengths in total. Conventional take-up systems are unidirectional, and do not envisage the need to release tension and/or run in reverse. Providing this functionality can be achieved in various ways. Some examples are provided below.
Where a moving peel-beak is provided, a spring element may be incorporated in the drive-train of the take-up system. The system will then automatically allow some lidding sheet to be released under sufficient tension from the indexing system. This forced release will generate extra spring potential energy, which will in turn effect the extra take-up required during peeling. The sprung biasing may be provided in various ways, for example:
Spring-induced tension in the lidding sheet may be combined with active movement of the tensioning component, allowing the system to reduce the maximum force experienced by the lidding sheet/spring(s).
In known systems, the inclusion of a spring in the drive train of the take-up system has been purely to compensate for the growing diameter of a take-up drum as used sheet is wound on during use. Springs have not previously been considered as a means of allowing the take-up system to run in reverse during indexing.
This approach involves actively controlling (for example, reducing or releasing) the tension in the lidding sheet a sufficient amount to allow the peel-front to move substantially with the medicament carrier by the required amount to avoid substantial or undesirable peeling. There are several ways in which this can be achieved, including:
Another advantage of separating indexing and peeling is that it allows some of the device's operations, such as indexing one or both wheels in a dual-strip device, to be carried out during cap-close (or another analogous reverse operation of the actuator). The required user input can then be distributed over an even greater range of motion, ie over more than one section of actuator operation, to further reduce the required force and further smooth operation.
The inhaler device according to the first aspect comprises an actuation mechanism having an indexing system for advancing a medicament carrier comprising a base with a plurality of medicament pockets or blisters and a peelable lidding sheet, such as a lidding foil, covering the blisters, an opening system for peeling the lidding sheet from the medicament carrier to open a blister, and a common actuator for the indexing system and the opening system, wherein the common actuator is movable between a first position and a second position via an intermediate position, and wherein progression of the opening system is disproportional to progression of the indexing system during movement of the common actuator.
In use, movement of the common actuator through a single defined range of motion causes movement or progression of the indexing system sufficient to advance a medicament carrier by a single dose and movement or progression of the opening system sufficient to completely remove the lidding sheet from a corresponding length of the medicament carrier, but the movements of the opening system and of the indexing system are not proportional. In other words, the speed ratio or percentage of total movement/progression of the opening system and indexing system are not constant during operation of the inhaler device.
Movement of the common actuator through a first range of motion may cause operation of the indexing system and movement of the common actuator through a second range of motion causes operation the opening system, and the indexing system may be dissociated (eg decoupled or separated) from the opening system so that said first range of motion is not the same as said second range of motion. The dissociation of the opening system and indexing system enables one to move largely independently of the other so that their movement need not be proportional, as in the prior art.
A defined movement of the common actuator may operate both the indexing system and the opening system, and the speed of movement of the opening system relative to the speed of movement of the actuator may vary during said defined movement of the actuator.
Alternatively, a defined movement of the common actuator may cause operation of the indexing system to advance one dose of medicament and cause the opening system to move through a first phase of operation in which said peeling occurs without exposing medicament in a blister and a second phase of operation in which medicament in a blister is exposed by said peeling, to thereby present a dose of medicament ready for inhalation, and said second phase of operation of the peeling system may be delayed until said operation of the indexing system is 30% complete. Some peeling of the lidding sheet may take place early in the operation of a device, but a critical part of the operation, when a sheet is peeled over the edge of a blister pocket and a medicament is actually exposed, is delayed until later in the operation.
The second, or critical, phase of operation of the opening system may be delayed until said operation of the indexing system is 50% complete, or 60%, 70%, 80%, 90%, 95% or 100% complete.
The dose of medicament may be defined as the dose to be delivered by the inhaler device according to a particular dosage regime. This may comprise the contents of a single blister, or a pair of blisters, or more as required.
The defined movement may be movement from the first position to the second position, or movement from the second position to the first position and back to the second position, for example.
Movement of the common actuator from said first position, for example any movement away from the first position, may advance the indexing system, and only movement of the actuator beyond the intermediate position may actuate the opening system.
Reverse movement of the actuator from a position between said first position and said intermediate position back to said first position may result in reversing of said advancement of the indexing system. This helps to avoid partially advancing and/or exposing doses during incorrect or incomplete actuation of the inhaler device. An actuator can be moved up to a point, for example the point of peeling or exposure of a dose, and then returned to its initial position without leaving a dose partially advanced or exposed. The next ‘correct’ or full operation of the inhaler device is, therefore, not compromised by an incorrect or incomplete actuation. This is particularly relevant where indexing begins immediately on movement of the actuator.
Movement of the actuator between the second position and the first position, i.e. in a direction moving from the second position towards the first position, may also result in advancement of the indexing system.
The inhaler device may further comprise a central hub driven by the actuator.
The inhaler device may further comprise a gear linkage or a cam system, for example a cam plate, to transmit drive from the hub to the index system.
The actuation mechanism may further comprise a trigger component, movement of which triggers the opening system. The trigger component may be a linearly moving component such as a push rod or slider for releasing a sprung biased component within the opening system.
Movement of the common actuator past the intermediate position may result in movement of the trigger component.
The actuation mechanism may further comprise a cam for controlling the opening system.
The actuation mechanism may further comprise a lidding sheet take-up component for receiving used lidding sheet peeled from a medicament carrier, and a drivetrain between the common actuator and the lidding sheet take-up component. The drive train may comprise the central hub.
The actuation mechanism may comprise means for regulating tension generated in a lidding sheet during advancing of the indexing system. The system may be active (eg driven) or passive allow minimal tension in a lidding sheet when the device is left or stored with the actuator in the first position.
A torsion spring may be provided between two rotating components provided on a common centre in the drivetrain. For example, a torsion spring may be provided between two stacked gears in a geared drivetrain. The two rotating components may be within a central logic hub, or within a further driving element within the drivetrain, or may form a sprung idler.
The torsion spring is charged due to tension in the used lidding sheet during advancing of the indexing system. This may provide a form of passive tension regulation in a lidding sheet.
The drivetrain may actively move, for example rotate, the lidding sheet take-up component to regulate tension in the lidding sheet, for example reduce tension or create slack in a lidding sheet, before or during advancing of the indexing system.
At least some of the peeled lidding sheet, for example slack generated by active tension regulation, may be turned back over an unopened section of a medicament carrier during advancing of the indexing system.
The inhaler device may further comprise a peel-beak component for regulating separation of a lidding sheet from a medicament carrier. The peel-beak component may, in particular, resist peeling/separation of a lidding sheet at a location on the medicament carrier which is adjacent the peel-beak in use.
The peel-beak component is movable during or before advancement of the indexing system. For example, the peel-beak may move with a component of the indexing system during indexing
The peel-beak component may follow a path substantially coincident with or offset from the path of a medicament carrier.
The peel-beak component may selectively engage with a component of the indexing system, for example with a moving indexer such as an index wheel.
The peel-beak component may comprise a pawl or ratchet that selectively engages with said component of the indexing system.
The indexing system may comprise means for indexing first and second medicament carriers each comprising a base with a plurality of medicament pockets or blisters and a peelable lidding sheet covering the blisters. Means may be provided for advancing more than two medicament carriers.
The opening system may be configured for peeling the lidding sheet from each of the first and second medicament carriers, and movement of the common actuator from said first position may result in operation of the indexing system to advance the first medicament carrier, but only movement of the actuator beyond the intermediate position may result in actuation of the opening system to peel the lidding sheet from a blister of the second medicament carrier.
The indexing system may comprise separate first and second indexers for indexing said first and second medicament carriers.
The indexing system may advance the first and second indexers disproportionally, i.e. such that the progression of the first indexer is disproportional to the progression of the second indexer.
An inhaler device is also provided comprising an actuation mechanism having an indexing system comprising first and second indexers for advancing first and second medicament carriers, and a common actuator for the first and second indexers, wherein the common actuator is movable between a first position and a second position via an intermediate position, and wherein progression of the first indexer is disproportional to progression of the second indexer. The progression may take place during or after movement of the common actuator, for example the progression may be driven by a spring force released after movement of the actuator is complete.
The first indexer and the second indexer may, in particular, not be advanced simultaneously during movement of the common actuator, ie their movement may be mutually exclusive.
Movement of the common actuator through a first range of motion may cause operation of the first indexer and movement of the common actuator through a second range of motion causes operation the second indexer, and the first indexer may be dissociated from the second indexer so that said first range of motion is not the same as said second range of motion.
The indexing system may advance one of the first and second indexers as the common actuator is moved from said second position to said first position.
At least one, and possibly both, of the first and second indexers may comprise an index wheel.
The indexing system may alternatively comprise a single indexer, which may comprise an index wheel.
The or each index wheel may be rotatable to advance a medicament carrier in the form of a blister strip, and may comprise cavities for receiving individual blisters of the blister strip.
The opening system may be configured to simultaneously peel open a blister on each of said first and second medicament carriers.
Said intermediate position of the common actuator may be closer to said second position of the common actuator than to said first position of the common actuator. For example, the intermediate position may be within the final 45%, 35%, 25%, 20% or 15% A of the total movement between said first and second positions, or of a full range of movement of the common actuator.
Said intermediate position of the common actuator may be adjacent said second position of the common actuator, for example within 0-10% of the said movement of the common actuator, and/or within 10° where the actuator moves in an arc.
The actuation mechanism may comprise one or more gears with intermittent drive and/or locking surfaces. This enables intermittent drive and/or locking of the elements of the actuation system (eg lidding sheet take-up components, individual indexers, moving peel-beaks, etc) during use.
The indexing system may comprise locking means for selectively preventing movement of one or more components, for example one or more indexers/index wheels, of the indexing system.
The locking means may comprise one or more gears with locking surfaces, to provide a Geneva lock, and/or one or more pawls.
The actuator may comprise a mouthpiece cover, and the first position may be a fully closed position of the mouthpiece cover, i.e. a position of the mouthpiece cover in which a mouthpiece of the inhaler is fully covered. The second position may be a fully open position of the mouthpiece cover, i.e. a position of the mouthpiece cover in which a mouthpiece of the device is fully uncovered.
Alternatively, the actuator may comprise a separate lever, button or other actuator, and the first and/or second positions may be defined stop positions of the actuator.
The inhaler device may further comprise a movable airway component, either as a unitary movable airway or as part of a split airway comprising a stationary airway component and the movable airway component. The movable airway component provides a peel-beak component for regulating separation of a lidding sheet from a medicament carrier.
The movable airway component may follow a path that is not substantially coincident with or merely offset from the path of a medicament carrier. For example, the movable airway component may follow a substantially linear path. A medicament carrier may, for example, follow a curved or circular path.
This invention can be employed in a device containing one or more medicament carriers, to release formulation for inhalation by the user in a mechanically advantageous fashion, while minimising the risk of accidental exposure of the formulation to the environment through unintended peeling.
Wherever practicable, any of the essential or preferable features defined in relation to any one aspect of the invention may be applied to any further aspect. Accordingly, the invention may comprise various alternative configurations of the features defined above.
Practicable embodiments of the invention are described in further detail below by way of example only with reference to the accompanying drawings, of which:
A mid chassis 4 defines interior chambers and pathways of the device for receiving the and guiding the blister strips, and a rear chassis 6 provides mounting posts for various rotating components 12,14,22,24,30 within the device. An airway manifold 8, comprising a feature to allow interfacing with a mouthpiece, is received in an opening at the top of the mid chassis 4, and a moveable mouthpiece cover 10 (of which, for clarity, only the rear half is shown) is also provided.
First and second index wheels 12,14 each provide recesses 13,15 for receiving blister pockets of two separate blister strips and advancing them into place beneath openings 16 in the airway manifold 8 as the first and second index wheels 12,14 are rotated. The unopened blister strips are coiled and stored together in a storage chamber 18 defined by the mid chassis 4. From here, a first of the two blister strips is fed through a first passageway 20 in the mid chassis 4 and clockwise around the first index wheel 12, before the base foil is engaged with a first spool wheel 22. Similarly, the second blister strip is fed from the storage chamber 18 through a second passageway 26 and anticlockwise round the second index wheel 14, before its base foil is attached to a second spool wheel 24.
In use, the lidding foil from each of the first and second blister strips is separated from the base foil at the first and second index wheels 12,14 respectively. The first and second spool wheels 22,24 rotate with the first and second index wheels 12,14 to coil the used base foils. The two lidding foils pass either side of a tension balancer 28, which is mounted to the mid chassis 4 at a pivot 29, before being engaged with a common take-up drum 30. Rotation of the take-up drum 30 generates tension in the lidding foils when required to peel open the blisters in the first and second blister strips. Since both lidding foils are wound onto the same drum 30, a small imbalance in the tension of the first and second lidding foils can arise. However, a greater tension in the lidding foil running down either side of the tension balancer 28 will serve to bias the tension balancer 28 about the pivot 29 towards the other foil. This effectively shortens the path followed by the higher tension foil and lengthens the path followed by the lower tension foil until the tensions in the two lidding foils are balanced. Thus, maintenance of the tension in the lidding-foil within an acceptable range of tensions could be performed.
The central logic hub 36 is mounted concentrically with three driving gears 40,42,44, which surround and are selectively engaged by the central logic hub 36. A take-up drum drive gear 40 can be seen engaging gearing on the base of the take-up drum 30, and a first index wheel drive gear 42 can be seen engaging gearing on the first index wheel 12 and first spool wheel 22. Although obscured in
The rear chassis 6 also provides a channel 62 for receiving the slider 58, and a generally crescent shaped aperture 64. Inner and outer protrusions 66,68 formed on the mouthpiece cover 10 extend through the aperture 64. The aperture 64 also receives projections on the rear of the index driving ratchet wheel 46 and peel driving ratchet wheel 48 so that these components can be driven by rotational movement of the mouthpiece cover 10. More specifically, opening of the mouthpiece cover (clockwise movement from the position shown in
The slider 58 allows one of the index driving ratchet wheel 46 and peel driving ratchet wheel 48 to be ‘locked’ while rotation of the mouthpiece cover 10 rotates the other. This builds a biasing force in the torsion spring 56, which can then be released by moving the slider 58 to release the previously locked component.
The rear chassis 6 also provides first and second ratchet pawls 72,74 to selectively lock the first and second index wheels 12,14 respectively.
The rear of the index driving ratchet wheel 46 from the central logic hub 36 is shown in
The inner diameter of the ring-shaped boss 102 is large enough to receive the boss 78 of the index driving ratchet wheel 46 when the central logic hub 36 is assembled. When assembled, the projection 86 extending from the end of the boss 78 on the index driving ratchet wheel 46 passes through the slot 94 to extend from the rear surface of the plate 90 of the peel driving ratchet wheel 48 to the same extent as the projection 98 formed directly on the plate 90 of the peel driving ratchet wheel 48.
The assembly is shown, with the rest of the first index wheel drive train 52, in
A front view of the take-up drum drive train 60 is shown in
The plate 90 of the peel driving ratchet wheel 48 bears against a rear surface of the take-up drum drive gear 40, and its generally circular profile can be seen between the gear teeth of the take-up drum drive gear 40. Part of the take-up drum ratchet wheel 50 is also visible in the front view of
A rear view of the take-up drum drive train 60 is shown in
The mouthpiece cover 10 is also shown in cross section, including the inner and outer protrusions 66,68 formed thereon. The inner protrusion 66 is shown abutting the projection 86 of the index driving ratchet wheel 46 that extends through the a generally crescent-shaped slot 94 in the peel driving ratchet wheel 48. The outer protrusion 68 is shown abutting the projection 98 on the peel driving ratchet wheel 48. The slider 58 is also shown, with a tab 154 provided on the obscured front face of the slider 58 illustrated in broken lines. The tab 154 engages with either the recess 88 (not shown) in the index driving ratchet wheel 46 or with a similar recess 156 provided in the peel driving ratchet wheel 48 to selectively lock one or other component against rotation.
As illustrated in
The next stage in operation is shown in
The peel driving ratchet wheel 48 has also been further rotated, past a commitment point where the radial protrusion 153 and angled surfaces provided on the recess 88 of the index driving ratchet wheel 46 and the recess 156 provided in the peel driving ratchet wheel 48 guide/urge the slider 58 radially outwards to move the tab 154 from the recess 88 into the recess 156. The now freed index driving ratchet wheel 46 has been driven by the torsion spring to ‘catch up’ with the peel driving ratchet wheel 48 by rotating in an anticlockwise direction until the projection 86 of the index driving ratchet wheel 46 abuts the inner protrusion 66 of the mouthpiece cover 10. As described in relation to
The indexing operation also applies tension to the first used lidding foil, but this only serves to take up the slack created by the clockwise rotation 160 of the take-up drum 30. As a result, the lidding foil is not peeled from the blister strip, but is instead doubled back over the unopened blister strip in a space provided between the first index wheel 12 and openings 16 in the airway manifold 8. This is shown in greater detail in
In
The sudden rotation 144b of the take-up drum applies tension to both lidding foils simultaneously, to expose the next dose in each blister strip for inhalation. As described in relation to
Once a user has inhaled the exposed dose, the inhaler is back in the configuration shown and described in
The second index wheel 14 has not been rotated at this stage, so the second lidding foil 172 remains slack. As such, any excess tension 176 that may be generated in the first lidding foil 170 by sudden movement of the first index wheel 12 can be accommodated by movement 178 of the tension balancer 28 towards the second lidding foil 172. The tension balancer 28 can thus acts as a further means to release or manage tension so that minimal tension is maintained in both lidding foils 170,172 with the mouthpiece cover 10 closed, even though the first index wheel 12 has already been advanced/indexed in this position.
It will be understood, from the foregoing description, that the operation of the mechanism of the inhaler device 2 comprises several separate actions that arise from a single actuation of the mechanism (movement of the mouthpiece cover 10), and that these actions encompass a number of commitment-points. Potential problems that may arise if some commitment points are passed while others remaining unreached during include, for example:
It is therefore beneficial for such actions to be tied or linked together, so that they are no longer separable and have to occur with sufficient synchronisation to avoid these issues.
This inhaler device 2 described above uses a ‘catch-up’ mechanism. As the mouthpiece cover 10 is opened it drives the index driving ratchet wheel 46, which rotates by the opening-angle before releasing the slider 58. The slider 58 releases the peel driving ratchet wheel 48 to rotate until peeling is complete. During closure of the mouthpiece cover 10, the peel driving ratchet wheel 48 is driven back until it resets the slider 58. This in turn releases the index driving ratchet wheel 46 to rotate back until the first index wheel 12 has indexed.
Ratchets/pawls link the index driving ratchet wheel 46 to both first and second index wheels 12,14, as well as linking both index wheels 12,14 to the rear chassis 6, and the take-up drum 30 to the take-up drum ratchet wheel 50. The inhaler device 2 aims to ensure that all of these ratchet reset points are ‘slaves’ to the commitment points at which the slider 58 is released.
At the commitment point on mouthpiece opening, the slider 58 is forced down, or radially inwards, into the index driving ratchet wheel 46 by the peel driving ratchet wheel 48 by the angled surfaces provided on recesses 88,156. This results in a small final rotation in the index driving ratchet wheel 46 when the slider 58 is released and the peel driving ratchet wheel 48 is allowed to rotate. This final rotation provides a window for the resetting of ratchets, specifically those associated with the movement of the second index wheel 14 and the movement of the index driving ratchet wheel 46 relative to the first index wheel drive gear 42. Since they occur in that final section of movement of the index driving ratchet wheel 46, they will be tied to the movement of the peel driving ratchet wheel 48, and will be impossible to actuate separately.
On the return stroke, as the mouthpiece cover 10 is closed, the commitment point occurs when the peel driving ratchet wheel 48 has been rotated enough to push the slider 58 back out of engagement with the index driving ratchet wheel 46, causing it to rotate and effect the indexing of the first index wheel 12, with its associated ratchet-pawl reset. This indexing is thus tied to the commitment point, and neither can be actuated separately.
Various modifications to the described inhaler device are possible without departing from the scope of the overall inventive concept. For example, rotation of the first and second index wheels 12,14 may be selectively prevented by interacting curved Geneva lock surfaces provided on the first and second index wheels 12,14 and on the peel driving ratchet wheel 48, rather than by the first and second pawls 72,74 as described.
The peeling of the lidding sheet/foil may also be achieved by alternative means. For example, the index wheel may be arranged to move linearly while it turns and indexes the strip, effectively causing it to roll along the strip by one blister-pocket, before locking its rotation and translating its axle back to its original position. This would allow the lidding foil take-up system to peel the lidding foil as the index wheel translates. Alternatively, a movable peel beak may be provided to rotate with one of both of the first and second index wheels 12,14 during indexing, before being released to allow peeling of the lidding foil. These arrangements both essentially provide a moving peel front location, which avoids the need to actively back off the lidding foil tension and provide slack, and subsequently reapply tension to perform the peeling operation. This potentially allows a less complex overall mechanism to be provided.
An example of a moving peel-beak arrangement is shown in
A moving peel-beak component 290 is provided around the index wheel 214. The moving peel-beak component 290 defines the peel front, and comprises a ratchet pawl 292, which is shown in engagement with ratchet teeth 296 provided on or associated with the indexing wheel 214. A pin 294 is provided on the ratchet pawl 292 so that a sprung peel actuator (not shown) can disengage the ratchet pawl 292 from the ratchet teeth 296 when required.
A storage hub 218, for storing the unused blister strip, is also shown. The storage hub 218 comprises front, or inner, and rear, or outer, gears 218A,218B with a torsion spring arranged therebetween. The inner gear 218A is driven by rotation of the input hub gear 236 as shown, and this drive is directly transferred to the index wheel 214 and spool wheel 224 to advance the blister strip. The take-up drum/hub 230 is, instead, engaged with the outer gear 218B. As the moving peel-beak 290 rotates with the index wheel 214, the tension generated in the lidding foil rotates the take-up drum/hub 230 against the take-up direction, driving the outer gear 218B in the opposite direction to the inner gear 218A and charging the torsion spring in the storage hub 218.
When a dose is to be opened, the peel actuator (not shown) engages with the pin 294 to release the ratchet pawl 292 from the ratchet teeth 296. This frees the moving peel-beak component 290 to rotate relative to the index wheel 214. The charged torsion spring then drives the rear/outer gear 218B to take up the lidding foil and peel the dose open as the index wheel 214 is held stationary.
The moving peel-beak component 290 also includes an extra section of airway (not shown) to provide a passageway between a peeled dose/blister on the index wheel 214 and the mouthpiece of the inhaler device.
The mechanism shown in
An exploded view of a complete inhaler 202 incorporating the moving peel-beak component 290, is shown in
Equivalent components making up the right-hand side of the mechanism are also shown in
Briefly, this second embodiment of an inhaler according to the invention comprises a moving mouthpiece cover connected to a central hub comprising a pair of unidirectional ratchet wheels each associated with a separate gear train. This allows the action of closing the mouthpiece cover to advance a first index wheel, while opening the mouthpiece cover advances a second index wheel. The central hub also incorporates a cam track for controlling movement of the spring peel actuator. The peel actuator is released to free a pair of peel-beak components as described above when the mouthpiece cover is opened beyond an intermediate position or commitment point, and is reset on mouthpiece closure. The peel actuator is constrained to a linear motion.
After a dose is inhaled, the right-hand side of the mechanism is the first to advance, so the right-hand side components will hereafter be referred to as the first index wheel 212, first spool wheel 222 etc.
A front view of the assembled mechanism is shown in
During closure of the mouthpiece cover 210, the input gear 236′ directly drives inner gear 218A′ of the storage hub 218′, and this direct drive is transferred to the first index wheel 212 (via the additional gear 228—see
When the mouthpiece cover 210 is opened, the front ratchet ring 240′ is rotated in the direction of arrow 234. This causes the ratchet pawls 250′ to deflect, so that no drive is transmitted to the mechanism during mouthpiece opening.
It will be understood, therefore, that the two unidirectional ratchet rings 240,240′ drive different halves of the mechanism on closing and opening of the mouthpiece. In particular, the first index wheel 212 is driven only during closure of the mouthpiece 210 and the second index wheel 214 is driven only during mouthpiece opening.
The peel actuator 258 is shown in isolation in
When the mouthpiece cover 210 is fully open, the pin 260 reaches the right end (as shown) of the cam track 241, and can then move into a straight part 248 of the cam track 241, which is arranged substantially vertically relative to the inhaler body in the fully open position. This provides a commitment point, occurring shortly after the second index wheel 214 has been advanced by one step/dose, at which the peel actuator 258 is freed to move vertically, under the force of its spring, and release the peel-beaks 290,290′ to uncover a dose for inhalation by a patient.
A further embodiment of the present invention is illustrated in
The mechanism is formed from several geared components are held in place by a mid chassis 304 and a rear plate 306.
Two blister strips 366,368 are also shown side by side so that the individual pockets of medicament in each strip sit side by side in recesses in an indexer 312 in the form of a double-height index wheel located towards the top of the inhaler. A moving peel-beak component 390 is also provided.
Also shown are a spool wheel 322, for advancing and receiving the used base sheets/foils of the blister strips 366,368, and a take-up drum 330 for receiving used lidding sheet/foil. A sprung idler 318, formed from front and rear gears 318A,318B with a torsion spring 356 arranged therebetween, along with first and second idler gears 352,354.
A rear ratchet component 340 provides a connection to the mouthpiece cover 310, and fits within a cavity on the rear of a central input hub gear 336 to provide drive to the input hub gear 336 in only one direction.
The engagement of the rear ratchet component 340 with the input hub gear 336 can be seen, and it will be understood that the ratchet component 340 will drive the hub gear 336 when rotated in the direction or arrow 334 during mouthpiece cover opening, but can rotate relative to hub gear 336 the when rotated in the opposite direction as the mouthpiece cover 310 is closed.
It will also be understood that the clockwise rotation 334 (as viewed from the front of the inhaler) of the input hub gear 336 caused by opening the mouthpiece will be transferred to anticlockwise rotation 364 of the index wheel 312 as shown. A hook or pawl 392 can also be seen on the rear of the peel-beak component 390, and a pin 394 is shown proud of the remainder of the pawl 392.
Because of the counter rotation of the front and rear gears 318A,318B during the indexing operation, the torsion spring 356 is sufficiently charged to drive the take-up hub 330 the equivalent of two steps or doses. This ensures that the take-up hub re-coils the ‘released’ lidding sheet (necessary to allow movement of the peel-beak component 390) and also to peel open a new dose.
The pawl 392 on the peel-beak component 390 automatically engages with the next ratchet tooth 316 of the index wheel during this movement. The rear plate 306 also provides a pawl 372 is a that engages with axial ratchet teeth 320 on the rear of the index wheel 312 to prevent reverse rotation of the index wheel 312 while a dose is peeled and to provide resistance to the ratchet component 340 as the mouthpiece is closed ready for the next use.
An exploded view of the inhaler 402, with the outermost housing/body components omitted, is shown in
For clarity, only the components making up the right-hand drivetrain are labelled in
A first index wheel 412C, with pockets for receiving individual blisters of a blister strip 466, and first index drive gear 412D make up the remainder of the first indexer 412, and are shown at the front of the exploded view. When assembled, the rear index output gear 412B is received within the front index output gear 412A but is free to relate relative thereto. The front index output gear 412A is rigidly connected to the first index wheel 412C, and the first index drive gear 412D is rigidly connected to a pin 413 extending from the first index wheel 412C.
A similar arrangement on the left-hand side of the inhaler 402 makes up a second indexer 414 for engagement with a second blister strip 368. As illustrated in
A first moving peel peak component 490 is arranged around the first index wheel 412C. The peel-beak component 490 includes a ratchet pawl 492 for selective engagement with recesses 416 in a front face of the first index wheel 412C. When assembled, the front face of the peel-beak component 490 is substantially flush with the front face of the front plate 405.
A central input hub gear 436 is provided in front of the front plate 405. The central hub gear 436 is driven by a cam follower 480 which is moved by an arm 440 connected to the mouthpiece cover 410. A curved cam track 461 is provided in the front plate 405 to control movement of the cam follower 480 relative to the arm 440, as will be described later, against the force of a stabilising spring 482 provided between the cam follower 480 and a further part of the arm 440.
A further guide channel 459 in the front plate 405 receives a peel actuator 458, in the form of a push rod, and constrains it to a linear movement. The peel actuator 458 has a drive pin 460 at its lower end and a pair of prongs 462 at its upper end. The prongs 462 are positioned just proud of the front face of the front plate 405 in the assembled inhaler 402 so that each prong 462 can engage a ratchet pawl 492 of a peel-beak component 490 when the peel actuator 458 moves vertically. The peel actuator 458 also has a guide pin 463 for engagement with a generally circular cam track 441 provided on the rear surface of the hub gear 436.
A generally circular cam track 441 is also provided on the rear of central hub gear 436. The cam track 441 forms a closed loop with four quarters each having a straight angled section 442, a constant radius section 444 and a straight radially outwardly extending section 448. Each radially outwardly extending section 448 is located between the offset groups of teeth 416,420 on the front and rear halves of the central hub gear 436.
The first index drive gear 412D and second idler 454 are shown in
The second idler 454 comprises front and rear gear wheels separated by a reduced diameter central section and is shown from the rear in
A front view of the assembled mechanism is shown in
The peel actuator 458 is at the top of the guide channel 459, with the prongs 462 sandwiched between the first and second index drive wheels 412D,414D and the first and second moving peel-beak components 490,490′. The cam follower 480 and spring 482 are assembled with the arm 440, which is moved in a clockwise direction 434 when the mouthpiece cover is opened, moving the cam follower 480 along the curved cam track 461. This movement will be explained in the following Figures, where hidden parts of the mechanism are shown in broken lines.
The mechanism is shown after further rotation in
The spacing of the groups of teeth 416,420 on the central hub gear 436 ensures that the second index drive wheel 414D is only advanced after the first after the index drive wheel 412D has been advanced by one step. The peel actuator 458 has been maintained in a withdrawn position during the rotation by engagement of its guide pin 463 with the constant radius section 444 of the generally circular cam track 441.
As shown in
Further rotation of the arm 440 from the position shown in
As shown in
As previously described, the first index drive gear 412D is driven by rotation of the central hub gear 436 during opening of the mouthpiece cover 410. This causes the indicated rotation of the front index output gear 412A, which drives the front gear 418A of the sprung idler 418 as shown. The front gear 418A of the sprung idler 418 is engaged with the first idler gear 452, which in turn is engaged with the first spool wheel 422 to drive and coil the used base sheet. It will be understood that the second drive train operates similarly for the second indexer 414 and second spool wheel 422′.
A strain is applied to the used lidding sheets as the first and second indexers 412,414 are advanced, due to the moving peel beak components 490,490′, and this causes rotation of the first and second take-up drums 430,430′. As illustrated on the second drivetrain, the second take-up drum 430′ is engaged with the rear index output gear 414B of the second indexer, which acts as an idler transmitting drive to the rear gear 418B′ of the second sprung idler 418′. The counter rotation of the front and rear gears 418A′,418B′ stores energy in the torsion spring 456 during indexing. This energy is released when the peel actuator 458 releases the peel-beak components 490,490′, and is sufficient to rotate the second take-up drum 430′ to peel a dose.
An exploded view of the internal components of an inhaler 501 according to the fifth embodiment is shown in
To the rear side of the mid chassis 504 various geared components are shown which make up first and second geared drivetrains. Only the components making up the first drivetrain, namely a first spool wheel 522, first take-up drum 530 and first and second idlers 552,554 are shown. The geared parts of each of the first and second indexers 512,514 extend past the rear of the mid chassis 504 to engage with the first and second geared drivetrains respectively. Front faces of the first and second indexers 512,514 extend through cut-out sections in the front plate 505, and of the respective moving peel beak components 590,590′ are located in front of the front plate 505 so that they are exposed to a cam plate 536. A hub component 538 connects the cam plate 536 to a movable mouthpiece cover (not shown).
The rear surface of the cam plate 536 also comprises a driving pin 540 which engages with one of six slots 542 provided on the front face of the first indexer 512 to drive rotation of the first indexer 512 during closure 532 of the mouthpiece cover. Also provided are a pair of peel-beak pins 562 to control movement of the moving peel-beak components 590,590′ during use of the inhaler device 501.
The first and second moving peel-beak components 590,590′ are free to rotate relative to the first and second indexers, with no engaging latch or ratchet pawl provided. Their movement is instead regulated by the engagement of the peel-beak pins 562 with the first peel-beak cam track 551 or second peel-beak cam track 561. Meshing gear teeth 596 provided on each of the moving peel-beak components 590,590′ ensures that their movement is coupled, such that engagement of a peel-beak pin 562 with either peel-beak cam track 551,561 will control movement of both peel-beak components 590,590′.
For example, as shown in
The gearing on the rear of the inhaler device is shown in
A second similar drivetrain is provided for the second indexer 514, although a pair of second idlers 554′ are provided between the rear gear 518B′ of the second indexer 514 and the second take-up drum 530′.
Movement of the various components is illustrated in
The initial stage of closing the mouthpiece cover, from
Subsequent opening of the mouthpiece cover, as shown in
It will be understood that the peel-beak components 590,590′ move first after actuation of the inhaler device 501, so that the peel front is always ahead of the next dose to be peeled from the inhaler device. No peeling action is then performed until a set commitment point, when the peel-beak pins 562 are in the actuation positions 592 within the cam tracks 551,561 of the first and second peel-beak components 590,590′.
An exploded view of an inhaler 601 according to the sixth embodiment is shown in
A mouthpiece and airway manifold 608 is provided in front of the mid chassis 604, and comprises a split airway with a first half 690 that can reciprocate vertically during use while a second half 691 remains stationary.
A ring gear/cam plate 636 is provided as a means to control/drive the movement of all components of the inhaler device 601, and can therefore be considered a central logic hub. Inwardly extending gear teeth 616 on a ring gear drive the indexers 612,614, spool wheels 622,624 and take-up drums 630,630′. A cam track 651 is also provided to engage a pin 662 on the first half 690 of the airway to control its vertical movement.
A unidirectional ratchet component 640 provides a connection to the mouthpiece cover (not shown) and fits within a cavity on the rear of a central input hub gear 638 to provide drive to the input hub gear 638 in only one direction. The hub gear 638 engages, in turn, with the rear of the ring gear/cam plate 636, so that movement of the mouthpiece cover is transmitted to the ring gear/cam plate 636.
The vertical movement of the first half of the airway 690 is indicated by arrows 642 and 648. As will be described more fully with reference to later figures, the first and second indexers 612,614 are rotated sequentially in the directions indicated during use. As the first indexer 612 is advanced, the first half 690 of the split airway is moved upwards 642, moving the peel front in the same direction as the blister strip to delay the peeling operation. Subsequent downward movement 648 then serves to peel the lidding sheet from the base sheet to peel a dose of medicament. The linear movement of the first half 690 of the split airway therefore provides a moving peel beak component 690 to regulate the peeling operation as in other embodiments.
The rear view of
A first cross section of the inhaler device, looking from the rear side, is shown in
The operation of the inhaler device will be described with reference to both
As the ring gear/cam plate 636 is rotated in the direction of arrow 634, during opening of a mouthpiece cover, the inwardly extending teeth 616 first engage with the first idler 652 to drive the first indexer 612 and the first spool wheel 622 to rotate. The cam track 651 simultaneously guides the movement of the pin 662 in as shown by arrow 642, which causes a vertical upwards movement of the first half 690 of the split airway during rotation. The first indexer 512 therefore advances a dose, while the upwards movement of the split airway 690 adjusts the peel front location so that a dose is not peeled. This creates tension in the lidding sheet of a first blister strip, which in turn rotates the first take-up drum 630 relative to its drive gear 618, storing energy in the torsion spring provided therebetween as the necessary length of lidding strip is released.
When the first indexer 612 has been advanced by one step/dose, the curved surface 672 of the first idler 652 again engages with a smooth section 617 of the ring gear/cam plate 636 to hold the first indexer stationary as the rotation 634 of the ring gear/cam plate 636 continues. Further inwardly extending teeth 616 then engage first with the second indexer 514 and then with the drive gear 618′ of the second take-up drum 630′ to advance these components and to index and peel a second blister strip as the mouthpiece cover continues to open. During advancement of the second indexer 614 the split airway 690 is maintained in a raised position as the pin 662 moves through a section of the cam track 651 indicated by arrow 644. Gearing between the drive gear 618′ of the second take-up drum 630′ and the drive gear 618 of the first take-up drum 630 further charges the torsion spring of the first take-up drum 630.
When both indexers have been advanced by one step/dose, the curved surfaces 672,673,674 are again engaged with a smooth sections 617 of the ring gear/cam plate 636 so that both indexers 612,614 are held against rotation. The pin 662 is then at an actuation position or commitment point 692 in the cam track. At this point, the cam track 651 and actuation position 692 will be rotated to a position where movement of the pin 662 in the direction of arrow 648 provides the previously indicated downwards movement of the split airway 690. The torsion spring in the first take-up drum 630 pulls the first lidding sheet and split airway portion 690 downwards, peeling a dose from the first blister strip. Doses from both strips are thus exposed for inhalation once the cap is fully opened, but the second strip is only peeled after half of the opening operation has been completed, and the first strip is only peeled after a defined commitment point close to the end of the opening operation.
Subsequent closing of the mouthpiece cover provides no drive to the mechanism, because of the ratchet component 640. The engagement of the pin 662 with the cam track 651, and the Geneva locks previously described, help to ensure that there is no back rotation of any components so that the next actuation can be reliably performed.
A seventh embodiment of an inhaler 701 according to the present invention is illustrated in
As shown in the exploded view of
The mechanism of the inhaler 701 is driven by movement of a mouthpiece cover 710 which is connected to a unidirectional ratchet component 740 located in a recess in the rear side of a hub gear 738. The hub gear 738 drives a first input gear 736 which, in turn, drives a second input gear 736′. The first and second input gears 736,736′ respectively intermittently drive first and second indexers 712,714 and the first and second peel beak components 790,790′. Each of the first and second indexers 712,714 comprises an index gear 712A,714A and an index drum 7126,7146 assembled around a respective peel beak component 790,790′. The inhaler 701 also includes first and second slave beak components 791,791′ which interact with the first and second peel beak components 790,790′ as will be explained later.
The remaining components are largely similar to those described in previous embodiments. First and second spool wheels 722,724 are provided for the used base foils, and first and second take-up drums 730,730′, each connected to a drive gear 718,718′ via a torsion spring 756,756′, are provided for the used lidding sheet/foils of a pair of blister strips.
The first and second peel beak components 790,790′ both have toothed input sections 775,775′ which engage with the toothed sections 773,773′ of the first and second input gears 736,736′ adjacent the end of the bosses 772,772′. Small recesses 776,776′ are also provided in the outer edge of each peel beak component 790,790′ on either side of the toothed input sections 775,775′, and drive pins 762,762′ for engagement with a slot 751 provided at the rear of the airway 708. Arrows show the rotation direction of the components during use, and it should be noted that the first tooth 773A in the toothed section on the first input gear 736 is sculpted to increase efficiency during initial engagement when the first input gear 736 initially starts to drive the first peel beak component 790. Although not labelled, similar sculpting is provided on a first tooth 773A′ on the second input gear for the same reason.
Advancement of the mechanism shown in
Once the first peel beak component 790 has been advanced as described above, continued movement of the mouthpiece cover 710 then engages the toothed section 773′ of the second input gear 736′ with the toothed input section 775′ of the second peel beak component 790′. The second peel beak component 790′ is thus advanced by the further opening movement, while the recess 776 provides a Geneva holding surface for engagement of the with the outer surface of the boss 772 and holds the first peel beak component 790 against further rotation as shown in
As described above in relation to
The first and second index gears 712A,714A are initially advanced by the first and second input gears 736,736′ along with the first and second peel beak components 790,790′ as described in relation to
The mechanism as described provides an oscillating or reciprocating movement of the first and second peel beak components 790,790′ and an intermittent rotation of the first and second indexers 712,714 from a common drive. The movement of the components, and of the moving airway 708, can be reliably synchronised. The first and second indexers 712,714 are advanced a quarter of a turn at a time to correspond to the four provided dose pockets for receiving drug pockets of a pair of blister strips.
A similar functionality could be achieved using a pin Geneva mechanism, with both halves of the overall mechanism having a single pin driving a stack of two Geneva wheels with a release area for one of the layers (the peel beak layer) enabling the back-driving of the beaks. However, using a gear drive as described provides a less variable force-profile, and avoids the need for an unsupported pin which may be weak and vulnerable to snapping.
The mechanism indexes a first side and drives the airway 708 down with the peel front, then indexes the second side moving that peel front to an opening of the mouthpiece 708 before both are released. As the peel beak components 790,790′ rotate back to their original position they are linked via the airway 708, which ensures simultaneous movement and drives the airway 708 into position in line with a revealed drug pocket of each blister strip.
The input drive to the mechanism is illustrated in the rear view
As in other embodiments the first and second spool wheels 722,724 simply receive and wind in the used base sheets/foils of first and second blister strips, while the first and second take-up drums 730,730′ receive the used lidding foils/sheets. The torsion springs 756,756′ provided between the drive gears 718,718′ and the take-up drums 730,730′ act in the same way as in earlier embodiments, to initially allow movement of a lidding foil with an indexer 712,714 and peel beak component 790,790′ while storing spring energy to subsequently drive the peeling operation, and to compensate for the increasing diameter of used lidding foil/sheets as the blister strips are used. The first and second take-up drums 730,730′ are geared to rotate in the opposite direction to their corresponding indexers 712,714, which further charges the torsion springs 756,756′ during indexing. This provides sufficient tension to move the lidding sheet/foils back past their peel-front and open the next dose on the strip when the peel beak components 790,790′ are released.
The inhaler 701 according to the seventh embodiment creates design freedom in terms of layout, timings, sequences, forces, torques, displacements, etc. The moving airway does not move on the same path (or offset from) as the blister-strips during use, because its movement is linear rather than rotational. This means that there is less chance of lidding foil being pinched between the moving airway 708 and the first and/or second index wheels 712,714, because they are only close to each other at the end of their travel during a peeling operation.
Unlike in the inhaler 601 of the sixth embodiment, there is just a single moving airway 708, rather than separate moving and sections, which would necessitate a clearance gap between the two sections. A simpler piston-type seal can therefore be used between the airway 708 and a mouthpiece of the inhaler 701.
An eighth embodiment of the invention will now be described with reference to
The exploded view of
The mechanism of the inhaler 801 is driven via the mouthpiece cover 810, which is directly coupled to a ratchet component 840 within a hub gear 838. The hub gear 838 permanently engages with and drives a first input gear 836, which extends through a front plate 805. The first input gear 836 engages with and drives a second input gear 836′.
The first and second input gears 836,836′ drive first and second peel beak components 890,890′. The peel beak components 890,890′ of the mechanism are formed in two parts, so that the first peel beak component 890 comprises a front part 890A and a rear part 890B assembled from opposite sides of a mid chassis 804. Similarly, the second peel beak component 890′ comprises a front part 890A′ and a rear part 890B′ assembled from opposite sides of a mid chassis 804. A locking arm 866 with a projection 868 is also provided behind the rear plate of the inhaler 801.
Detail views of the first indexer 812 and front and rear parts 890A,890B of the first peel beak 890 are shown in
Advancement of the mechanism during mouthpiece opening is illustrated in the front view of
Once rotation of the first peel beak component 890 is complete, as shown in
The engagement of the first indexer 812 with the drive gear 818 for the first take-up drum 830 and, via the first idler 852, the first spool wheel 822 is also shown in
Another inhaler 901, according ninth embodiment of the invention, is illustrated in
First and second indexers 912,914, spool wheels 922,924 and idler gears 952,954 are located between the rear plate 606 and a mid chassis 904, along with first and second take up drums 930,930′ (with associated input gears 918,918′). As in other embodiments, torsion springs (not shown) are provided to create sprung take up drums 930,930′ providing the benefits previously described. A moving peel beak component 990 is illustrated in front of the mid chassis 904, and comprises a drive pin 962 which extends through a slot in the mid chassis to constrain the peel beak component 990 to linear motion.
A front perspective view of the hub gear 936 is shown in
The movement of the peel beak component 990 and airway 908 during movement of the mouthpiece cover 910 is further illustrated in
Is should be clear that toothed sections 916 of the intermittent drive gear 936C will first advance the first indexer 912 (via the first idler gear 952) and then subsequently advance the second indexer 914. When the first and second indexers 912,914 are not being advanced, they are held stationary by Geneva style locking between smooth sections 917 of the intermittent drive gear 936C and the first idler 952 or second indexer 914. This is similar to the operation described for the sixth embodiment in
The previously described motion of the airway 908 and peel beak component 990 occurs during advancement of the first indexer 912 to prevent peeling of a first blister strip before a second blister strip is in the indexed position. This results in a lid foil/sheet of the second blister strip being overlaid (unspooled from the second take-up drum 930′ prior to its motion and laid back over the base foil/sheet) and then recollected when indexed.
The design of the cam tracks 951,961 ensures that the airway 908 moves synchronously with the first blister strip motion and is held in the forwards position until the second blister strip has been indexed into position, before a simultaneous peeling operation is performed at the commitment point shown in
The embodiments described above generally enables complex timing and sequencing to be provided with a low part-count, and provide inhalers that are tolerant of/resistant to misuse by a user without the need for a breath actuated mechanism. In many cases, the use of ratchets within the mechanism is largely avoided to minimise complex or confounding ratchet-timing issues that might otherwise prevent the device from recovering from deviations from the expected use-sequence and the concurrent indexing of two strips of medicament (where used) is avoided. The use of commitment points built into the mechanisms helps to address over-compliance issues.
It should be understood that, while the various embodiments described above provide their own individual features and benefits, they all achieve the same overall aim, namely disproportional progression of the opening system and indexing system of a single device during movement of the common actuator.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1812671.4 | Aug 2018 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2019/052184 | 8/2/2019 | WO | 00 |
