INHALATION COUNTER

Abstract

An inhalation counter (350, 450, 550) for an inhalation system (100) is provided. The inhalation system comprises a fluid flow passage (322) and the inhalation counter comprises an escapement wheel (352, 452), a biasing means (354, 454) for incrementing the escapement wheel, a conversion mechanism which, in use, is configured to perform a first action in response to a temporary increase in fluid flow rate through the fluid flow passage, and an anchor (356, 456). The anchor is coupled to the conversion mechanism and configured to interact with the escapement wheel so as to allow the biasing means to increment the escapement wheel in response to the first action of the conversion mechanism. A holder (300) and an inhalation system comprising the inhalation counter are also provided.

Claims

1. An inhalation counter for an inhalation system, the inhalation system comprising a fluid flow passage and the inhalation counter comprising: an escapement wheel; a biasing means for incrementing the escapement wheel; a conversion mechanism which, in use, is configured to perform a first action in response to a temporary increase in fluid flow rate through the fluid flow passage; and an anchor, wherein the anchor is coupled to the conversion mechanism and configured to interact with the escapement wheel so as to allow the biasing means to increment the escapement wheel in response to the first action of the conversion mechanism.

2. An inhalation counter according to claim 1, wherein the temporary increase in fluid flow rate comprises a first portion in which the fluid flow rate increases, and a subsequent second portion in which the fluid flow rate decreases, and wherein the conversion mechanism is configured to initiate the first action in response to the first portion of the temporary increase in fluid flow rate and complete the first action in response to the second portion of the temporary increase in fluid flow rate.

3. An inhalation counter according to claim 1, wherein the conversion mechanism comprises an actuator and the first action comprises movement of the actuator.

4. An inhalation counter according to claim 3, wherein the first action comprises a departing movement of the actuator from a first position to a second position, and a returning movement of the actuator from the second position to the first position, and the conversion mechanism is configured to resist the departing movement of the actuator.

5. An inhalation counter according to claim 1, wherein the conversion mechanism comprises a rotatable component and the first action comprises rotation of the rotatable component.

6. An inhalation counter according to claim 1, wherein the conversion mechanism comprises a flexible component and the first action comprises flexing of the flexible component.

7. An inhalation counter according to claim 1, wherein the inhalation counter comprises an indication means for indicating to a user information relating to an inhalation count of the inhalation counter.

8. An inhalation counter according to claim 7, wherein the inhalation counter comprises a modifying mechanism coupled to the indication means for resetting or otherwise modifying the information relating to the inhalation count.

9. An inhalation counter according to claim 8, wherein the modifying mechanism is configured to allow the user to set the information relating to the inhalation count.

10. An inhalation counter according to claim 1, comprising an energising mechanism for energising the biasing means.

11. An inhalation counter according to claim 7, comprising a combined modifying and energising mechanism for modifying the information relating to the inhalation count and energising the biasing means.

12. An inhalation counter according to claim 11, wherein the combined modifying and energising mechanism comprises a freewheel clutch.

13. A holder for use with an inhaler article, the holder comprising an inhalation counter according to claim 1.

14. A holder according to claim 13, wherein the inhalation counter is an inhalation counter according to claim 8, wherein one or more of the modifying mechanism, the energising mechanism and the combined modifying energising and modifying mechanism is operated by one or both of engaging the inhaler article with the holder and disengaging the inhaler article from the holder.

15. An inhalation system comprising an inhaler article and a holder according to claim 13.

Description

[0139] FIG. 1 is a cross-sectional view of an inhalation system comprising a holder and an inhaler article;

[0140] FIG. 2 is a cross-sectional view of an inhalation counter of the inhalation system of FIG. 1;

[0141] FIG. 3 is a cross-sectional view of a first alternative inhalation counter for an inhalation system; and

[0142] FIG. 4 is a cross-sectional view of a second alternative inhalation counter for an inhalation system.

[0143] FIG. 1 is a cross-sectional view of an inhalation system 100. The inhalation system 100 is a mechanical inhalation system consisting of non-electrical components. The inhalation system 100 comprises an inhaler article 200 and a holder 300 receiving the inhaler article 200.

[0144] The inhaler article 200 includes a body extending along an inhaler longitudinal axis from a mouth end 204 to a distal end 206. The mouth end 204 is for insertion into a mouth of a user. The distal end 206 opposes the mouth end 204. The inhaler article 200 comprises a capsule cavity disposed within the body and bounded downstream by a filter element and bounded upstream by an open tubular element defining a central passage. As used herein, the terms upstream and downstream refer to relative positions of components relative to a direction of fluid flow through the system during normal use. The inhaler article 200 comprises a capsule disposed within the capsule cavity. The central passage of the open tubular element forms an air inlet aperture extending from the distal end 206 of the body to the capsule cavity. The central passage has a smaller diameter than the capsule. As such, the capsule cannot fall through the central passage. The capsule comprises a dry powder. The dry powder comprises nicotine particles and flavour particles.

[0145] The holder 300 comprises a housing 302 defining a housing cavity. The holder 300 comprises a movable sleeve 306. The housing cavity is for receiving and retaining the sleeve 306. The sleeve 306 defines a sleeve cavity 308. The sleeve cavity 308 is for receiving and retaining the inhaler article 200. In FIG. 1, the inhaler article 200 is shown received in the sleeve cavity 308, and the sleeve 306 is shown received in the housing cavity.

[0146] The holder 300 comprises a piercing element 310 fixed to a distal end of the housing 302 and extending along a longitudinal axis of the holder 300 towards the housing cavity. The piercing element 310 is configured to activate or pierce the capsule disposed within the inhaler article 200. The holder 300 comprises a spring 312 configured to bias the sleeve 306 away from the piercing element 310. The holder comprises a sleeve resting component 311. In a resting position of the holder 300, as shown in FIG. 1, the sleeve 306 rests on the sleeve resting component 311 and the sleeve resting component 311 rests on the spring 312. The sleeve resting component 311 comprises a central opening. In use, the piercing element 310 is able to extend through the central opening of the sleeve resting component 311 when the sleeve 306 and sleeve resting component 311 are moved towards the piercing element 310 against the action of the spring 312.

[0147] The sleeve 306 comprises a first open end 314 and a second opposing end 316. The second opposing end 316 of the sleeve 306 comprises a central opening. This central opening is configured to allow an air flow to enter the sleeve cavity 308. This central opening is configured to allow the piercing element 310 to enter the sleeve cavity 308 when the sleeve 306 is moved along the longitudinal axis of the holder 300 towards the piercing element 310.

[0148] The holder 300 comprises a fluid flow inlet 318 and a fluid flow passage 322 extending from the fluid flow inlet 318 to the second end 316 of the sleeve 306. The holder 300 comprises an inhalation counter 350 coupled to the fluid flow passage 322.

[0149] In use, a user inserts the inhaler article 200 into the sleeve cavity 308 of the holder 300. The inhalation system 100 appears as shown in FIG. 1 at this stage. The user then presses the inhaler article 200 in the direction of the distal end 206 of the inhaler article 200. This compresses the spring 312 and moves the inhaler article 200, the sleeve 306, and the sleeve resting component 311 in a distal direction relative to the housing 302. As this happens, the piercing element 310 extends through the central opening of the sleeve resting component 311, then through the central opening of the sleeve 306, then into the sleeve cavity 308, then into the capsule cavity, before contacting and piercing the capsule. The user may then release the inhaler article 200. This will allow the spring 312 to expand and move the inhaler article 200, the sleeve 306, and the sleeve resting component 311 in a proximal direction relative to the housing 302, back to the resting position shown in FIG. 1. However, at this stage, the capsule has been pierced.

[0150] A user may then inhale on the mouth end 204 of the inhaler article 200. This causes air to flow in through the fluid flow inlet 318 of the holder 300 and through the fluid flow passage 322. This air flows through the central opening of the sleeve 306, then through the central opening of the inhaler article 200 and into the capsule cavity. Dry powder from the capsule is entrained by this air flow to form an aerosol. This aerosol flows through the filter element and is delivered to the user. The air flow path is indicated with several arrows in FIG. 1. The user may repeatedly inhale on the inhaler article 200. Each inhalation results in a temporary increase in fluid flow rate through the fluid flow passage 322. Each inhalation is counted by the inhalation counter 350 and an indication means of the holder 300 indicates to the user information relating to the inhalation count of the inhalation counter 350 through a viewing window of the holder 300. The interaction between the fluid flow and the inhalation counter 350 is explained in more detail below with reference to FIG. 2. After the capsule is fully consumed, for example after twelve inhalations, the indication means indicates this to the user. The user may then withdraw the inhaler article 200 from the holder 300. This action resets the inhalation counter 350 and energises a biasing means of the inhalation counter. This is described in more detail below.

[0151] FIG. 2 shows the inhalation counter 350 of the holder 300.

[0152] The inhalation counter 350 is coupled to the fluid flow passage 322 via a venturi tube 323. The inhalation counter 350 comprises an escapement wheel 352, a biasing means 354 in the form of a spiral spring for incrementing the escapement wheel 352, and a conversion mechanism. The conversion mechanism is configured to perform a first action in response to a temporary increase in fluid flow rate through the fluid flow passage 322. The inhalation counter 350 also comprises an anchor 356. The anchor 356 is coupled to the conversion mechanism and configured to interact with the escapement wheel 352 so as to allow the biasing means 354 to increment the escapement wheel 352 in response to the first action of the conversion mechanism. Specifically, the anchor 356 comprises a first anchoring prong 357 and a second anchoring prong 359, and the first anchoring prong 357 and the second anchoring prong 359 interact with teeth of the escapement wheel 352 to allow the biasing means 354 to increment the escapement wheel 352 in response to the first action of the conversion mechanism.

[0153] The conversion mechanism comprises an actuator 358 in the form of a piston. The conversion comprises a resistance component 360 in the form of a helical spring. The resistance component 360 is coupled to the actuator 358.

[0154] In use, an inhalation on the inhaler article 200 results in a temporary increase in fluid flow rate through the fluid flow passage 322, as explained above. The temporary increase in fluid flow rate may comprise a first portion in which the fluid flow rate increases, and a subsequent second portion in which the fluid flow rate decreases.

[0155] As the user inhales on the inhaler article 200, a fluid flow, specifically an air flow, is drawn in through the fluid flow inlet 318 of the holder 300. This fluid flow accelerates as it passes through the venturi tube 323 and results in a reduction in pressure in the venturi tube 323. This reduction in pressure acts to initiate the first action of the conversion mechanism.

[0156] The first action comprises movement of the actuator 358. Specifically, the first action comprises a departing movement of the actuator 358 from a first position to a second position, and a returning movement of the actuator 358 from the second position to the first position. The resistance component 360 is configured to resist the departing movement of the actuator 358.

[0157] In the inhalation counter 350 of FIG. 2, the departing movement of the actuator 358 comprises downward movement of the actuator 358. Thus, as a user begins to inhale on the inhaler article, the actuator 358 moves downwards, compressing the resistance component 360. This moves the anchor 356. Specifically, due to the coupling between the actuator 358 and the anchor 356, downward motion of the anchor 356 results in the anchor 356 pivoting clockwise about a pivot point 362 of the anchor 356. This disengages the first anchoring prong 357 of the anchor 356 from a first tooth of the escapement wheel 352. This allows the escapement wheel 352 to rotate a small amount under the action of the biasing means 354 before the second anchoring prong 359 of the anchor 356 engages a second tooth of the escapement wheel 352 to prevent further rotation. Thus, the first portion of the temporary increase in fluid flow results in less than a single increment of the escapement wheel 352. Whilst the fluid flow rate through the fluid flow passage 322 is sufficiently high, the pressure in the venturi tube 323 will be sufficiently low so as to retain the actuator 358 in its second position, thereby preventing further rotation of the escapement wheel 352 under the action of the biasing means 354.

[0158] Eventually, the fluid flow rate through the fluid flow passage 322 will begin to decrease. This is the second portion of the temporary increase in fluid flow rate. During, or very shortly after, this second portion of the temporary increase in fluid flow rate, the flow rate through the venturi tube 323 will decrease and the pressure in the venturi tube 323 will increase towards atmospheric pressure. As the pressure increases, the resistance component 360 expands and the actuator 358 moves upwards. That is, in a returning movement of the actuator 358, the actuator 358 returns from its second position back to its first position. As this happens, the anchor 356 rotates anti-clockwise about its pivot point 362. This disengages the second anchoring prong 359 from the second tooth of the escapement wheel 352. The escapement wheel 352 is then allowed to rotate a small amount under the action of the biasing means 354 before the first anchoring prong 357 engages with a third tooth of the escapement wheel 352. In this embodiment, the third tooth of the escapement wheel 352 is located adjacent to, and immediately behind, the first tooth of the escapement wheel 352. Thus, following the first action of the conversion mechanism, the escapement wheel 352 has undergone a single increment under the action of the biasing means 354.

[0159] The inhalation counter 350 further comprises an indication means 364 for indicating to a user information relating to an inhalation count of the inhalation counter 350. The indication means 364 comprises a pointer 366 and a substantially circular scale 368. The scale 368 is numbered from 0 to 29 along its outer surface. The pointer 366 remains fixed relative to the housing 302 of the holder 300 and points towards one of the numbers on the scale 368. Through the viewing window on the holder 300, a user can see the number towards which the pointer 366 is pointing at any given time. The scale 368 of the indication means 364 is coupled to the escapement wheel 352 so as to rotate relative to the pointer 366 when the escapement wheel 352 rotates. Thus, an incremental rotation of the escapement wheel 352 leads to a corresponding incremental rotation of the scale 368 relative to the pointer 366. In this sense, the scale 368 may be termed a rotary scale. In response to an inhalation, the first action of the actuator 358 causes the escapement wheel 352 and the scale 368 to be incremented, thus causing the pointer 366 to point at the subsequent number on the scale 368. In the embodiment shown in FIG. 1, each inhalation results in the number pointed at by the pointer 366 increasing by one. Thus, if the number is set to zero before the first inhalation, the inhalation counter 350 counts the number of inhalations on the inhaler article 200 and indicates this inhalation count to the user. However, as will be clear to one skilled in the art, the indication means 364 could indicate information to the user relating to the inhalation count in a number of ways. For example, the inhalation counter 350 could count down rather than count up. Equally, the gearing ratio between the scale 368 and the escapement wheel 352 could be adjusted such that the scale 368 rotates by a significantly smaller angle than the escapement wheel 352, and the scale 368 could simply include a coloured surface which, in response to inhalations, slowly fills the viewing window. Filling the viewing window could indicate that the inhaler article 200 has likely been fully consumed.

[0160] The inhalation counter 350 also comprises a combined modifying and energising mechanism (not shown). The combined modifying and energising mechanism is a manual winding mechanism on the holder 300 coupled to the scale 368. The user is able to manually rotate the winding mechanism to reduce, for example reset to zero, the inhalation count shown by the indication means 364. Due to the gearing mechanism shown in FIG. 2, as the user rotates the winding mechanism to reduce the inhalation count, the biasing means 354 is re-energised. This is because, the biasing means 354, in the form of a spiral spring, is coupled to a biasing means gear 355 which rotates as the winding mechanism is rotated, and this rotation causes energising (in other words, tightening or re-winding) of the biasing means 354.

[0161] The escapement wheel 352 does not rotate as the winding mechanism is rotated in this direction. This is because the escapement wheel 352 is coupled to an escapement wheel gear 372 by a freewheel clutch 370. Thus, when this gear rotates in an anti-clockwise direction, the scale 368 and the escapement wheel 352 rotate in a clockwise direction. But when this gear rotates in a clockwise direction, the scale 368 rotates in an anti-clockwise direction and the escapement wheel 352 does not rotate.

[0162] As would be clear to one skilled in the art, one could include a suitable mechanism such that the combined modifying and energising mechanism is operated by inserting the inhaler article 200 into the sleeve cavity, or removing the inhaler article 200 from the sleeve cavity.

[0163] FIG. 3 is a cross-sectional view of a first alternative inhalation counter 450 for an inhalation system. For example, the inhalation counter 450 could replace the inhalation counter 350 used in the inhalation system of FIG. 1.

[0164] The inhalation counter 450 would be coupled to the fluid flow passage 322 via a venturi tube (not shown). The inhalation counter 450 comprises an escapement wheel 452, a biasing means 454 in the form of a helical spring for incrementing the escapement wheel 452, and a conversion mechanism. The conversion mechanism is configured to perform a first action in response to a temporary increase in fluid flow rate through the fluid flow passage 322. The inhalation counter 450 also comprises an anchor 456. The anchor 456 is coupled to the conversion mechanism and configured to interact with the escapement wheel 452 so as to allow the biasing means 454 to increment the escapement wheel 452 in response to the first action of the conversion mechanism. Specifically, the anchor 456 comprises a first anchoring prong 457 and a second anchoring prong 459, and the first anchoring prong 457 and the second anchoring prong 459 interact with teeth of the escapement wheel 452 to allow the biasing means 454 to increment the escapement wheel 452 in response to the first action of the conversion mechanism.

[0165] The conversion mechanism comprises an actuator 458 in the form of a flexible membrane. In use, an inhalation on the inhaler article 200 results in a temporary increase in fluid flow rate through the fluid flow passage 322, as explained above. The temporary increase in fluid flow rate may comprise a first portion in which the fluid flow rate increases, and a subsequent second portion in which the fluid flow rate decreases, also as explained above.

[0166] As the user inhales on the inhaler article 200, a fluid flow, specifically an air flow, is drawn in through the fluid flow inlet 318 of the holder 300. This fluid flow accelerates as it passes through the venturi tube and results in a reduction in pressure in the venturi tube. This reduction in pressure acts to initiate the first action of the conversion mechanism.

[0167] The first action comprises movement of the actuator 458. Specifically, the first action comprises a departing movement of the actuator 458 from a first position to a second position, and a returning movement of the actuator 458 from the second position to the first position. The resilience of the flexible membrane naturally resists the departing movement of the actuator 458.

[0168] In the inhalation counter 450 of FIG. 3, the departing movement of the actuator 458 comprises downward movement of the actuator 458 to reach the position shown in FIG. 3. Thus, as a user begins to inhale on the inhaler article, the actuator 458 moves downwards. That is, in response to the reduction in pressure in the venturi tube, the flexible membrane flexes such that a central portion of the membrane moves downwards. This moves the anchor 456 in the same way the anchor 356 of FIG. 2 is moved by downwards movement of the piston.

[0169] Eventually, the fluid flow rate through the fluid flow passage 322 will begin to decrease. This is the second portion of the temporary increase in fluid flow rate. During, or very shortly after, this second portion of the temporary increase in fluid flow rate, the flow rate through the venturi tube will decrease and the pressure in the venturi tube will increase towards atmospheric pressure. As the pressure increases, the natural resilience of flexible membrane, or actuator 458, acts to move the actuator 458 upwards. That is, in a returning movement of the actuator 458, the actuator 458 returns from its second position back to its first position. As this happens, the anchor 456 rotates anti-clockwise about its pivot point 462 as described similarly in relation to upwards movement of the actuator 358 of FIG. 2. Thus, following the first action of the conversion mechanism, the escapement wheel 452 has undergone a single increment under the action of the biasing means 454.

[0170] The inhalation counter 450 further comprises an indication means 464 for indicating to a user information relating to an inhalation count of the inhalation counter 450. The indication means 464 comprises a pointer 466 and a substantially straight, linear scale 468. The scale 468 is numbered from 0 to 25. In this embodiment, the scale 468 remains fixed relative to the housing 302 of the holder 300. The pointer 466 points towards one of the numbers on the scale 468. For this embodiment, a substantially rectangular viewing window may be located on the holder 300 over the scale 468 and pointer 466 so that a user can see the number towards which the pointer 466 is pointing at any given time. The pointer 466 of the indication means 464 is coupled to the escapement wheel 452 so as to translate linearly upwards relative to the scale 468 when the escapement wheel 452 rotates. In this embodiment, a rack and pinion mechanism is used. Specifically, the pointer 466 is fixed to a linear gear 455, or rack, the escapement wheel 454 is coupled to an escapement wheel gear 472, or pinion, via a freewheel clutch 470, and the escapement wheel gear 472 is coupled to the linear gear 455, or rack. Thus, an incremental rotation of the escapement wheel 452 in response to an inhalation leads to a corresponding incremental rotation of the escapement wheel gear 472, and a corresponding incremental translation of the pointer 466 relative to the scale 468. In the embodiment shown in FIG. 3, this incremental translation of the pointer 466 causes the pointer 466 to point at a subsequent number on the scale 468. Thus, in the embodiment shown in FIG. 3, each inhalation results in the number pointed at by the pointer 466 increasing by one. So, if the number is set to zero before a first inhalation on the inhaler article 200, the inhalation counter 450 counts the number of inhalations on the inhaler article 200 and indicates this inhalation count to the user. However, as will be clear to one skilled in the art, the indication means 464 could indicate to the user other information relating to the inhalation count. For example, the inhalation counter 450 could count down rather than count up. The indication means 464 could also indicate to the user other information relating to the inhalation count in other ways. For example, the pointer 466 could include a coloured surface extending downwards which is approximately the length of the viewing window. Then, in response to inhalations, this coloured surface would upwards so as to slowly fill the viewing window. Filling the viewing window could indicate that the inhaler article 200 has likely been fully consumed.

[0171] The inhalation counter 450 also comprises a combined modifying and energising mechanism (not shown). The combined modifying and energising mechanism is operated by inserting the inhaler article 200 into the sleeve cavity. The mechanism is not shown in the Figures, but several options for this mechanism would be apparent to one skilled in the art. A single example is explained below.

[0172] The sleeve 306 may include a longitudinal slit extending from a top of the sleeve 306 downwards along a sidewall of the sleeve 306. A sleeve gear of a sequence of gears may be coupled to an escapement wheel gear 472 to which the escapement wheel 452 is coupled by a freewheel clutch 470. For example, when using a rack and pinion arrangement as shown in the embodiment of FIG. 3, the sleeve gear may be coupled, via the sequence of gears, to the rack to which the escapement wheel gear 472 is coupled. This sleeve gear may also extend partially through the slot and into the sleeve cavity. When a user inserts the inhaler article 200 into the sleeve cavity 308, the inhaler article 200 may engage with the sleeve gear and cause the sleeve gear to rotate as the inhaler article 200 is inserted deeper into the sleeve cavity 308. The sequence of gears couple this sleeve gear to the escapement wheel gear 472 so that, as the sleeve gear rotates, the escapement wheel gear 472 also rotates. Specifically, as the sleeve gear rotates, the escapement wheel gear 472 rotates in an anti-clockwise direction, thereby moving the pointer 466 downwards and compressing the helical spring, or biasing means 454. However, since the escapement wheel gear 472 is coupled to the escapement wheel 452 by the freewheel clutch 470, anti-clockwise rotation of the escapement wheel gear 472 does not rotate the escapement wheel 452. In this manner, engaging the inhaler article 200 with the holder 300, specifically inserting the inhaler article 200 into the sleeve cavity, operates the combined modifying and energising mechanism to reset the pointer 466 to zero and energise the biasing means 454. The sleeve gear may similarly be coupled to the sequence of gears by a freewheel clutch. This would ensure that any rotation of the sleeve gear in an opposite direction as the inhaler article 200 is removed from the sleeve cavity 308 does not act to cause rotation of the escapement wheel gear 472.

[0173] FIG. 4 is a cross-sectional view of a second alternative inhalation counter 550 for an inhalation system. For example, the inhalation counter 550 could replace the inhalation counter 350 used in the inhalation system of FIG. 1.

[0174] The inhalation counter 550 is identical to the inhalation counter 350 shown in FIG. 2 except that the actuator 358 in the form of a piston has been replaced by an actuator 558 in the form of a rotatable flap, the resistance component 360 in the form of a helical spring has been replaced by a resistance component 560 in the form of a torsional spring, and the actuator 558 is now coupled to the anchor 356 via a connecting rod 559. In the embodiment shown in FIG. 4, the first action of the conversion mechanism comprises rotation of the actuator 558 in a first direction, followed by rotation of the actuator in a second direction opposite to the first direction. This is explained in more detail below. Otherwise, the inhalation counter 550 of FIG. 4 functions in the same way as the inhalation counter of FIG. 2.

[0175] The inhalation counter 550 of FIG. 4 comprises an actuator 558 in the form of a rotatable flap. At least a portion of the flap is located in the fluid flow passage 322. The flap is urged towards a forward position, shown as a dotted line in FIG. 4, by the resistance component 560. The inhalation counter 550 comprises a connecting rod 559. A first end of the connecting rod 559 is pivotably connected to the anchor 356, and a second end of the connecting rod 559 pivotably connected to the flap.

[0176] In use, a user inhaling on the inhaler article 200 results in an air flow through the air flow passage 322 impinging upon the flap. During a first portion of the air flow, the air flow exerts a force on the flap acting to rotate the flap towards a back position, shown as a solid line in FIG. 4. This rotation from the forward position to the back position may be termed the departing movement of the actuator 558 and corresponds to downwards movement of the piston in FIG. 2. This motion causes the connecting rod 559 to move, thereby rotating the anchor 356 about its pivot point 362. Thus, rotation of the flap from the forward position to the back position causes rotation of the anchor 356 in the same way as downwards movement of the piston of the inhalation counter 350 of FIG. 2.

[0177] Towards the end of the inhalation, the air flow rate through the air flow passage 322 reduces. Thus, under the action of the resistance component 560 in the form of a torsional spring, the flap rotates from the back position to the forward position. This may be termed the returning movement of the actuator 558 and corresponds to upwards movement of the piston in FIG. 2. This motion causes the connecting rod 559 to move, thereby rotating the anchor 356 about its pivot point 362. Thus, rotation of the flap from the back position to the forward position causes rotation of the anchor 356 in the same way as upwards movement of the piston of the inhalation counter 350 of FIG. 2. This completes the first action of the conversion mechanism. All other details of the inhalation counter 550 of FIG. 4 are identical to the inhalation counter 350 of FIG. 2.

[0178] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term about. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A ?10% of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.