5,988,496
`[11] Patent Number:
`[19]
`Unlted States Patent
`
`Bruna
`[45] Date of Patent:
`Nov. 23, 1999
`
`U5005988496A
`
`[54] DOSE COUNTER FOR INHALERS
`
`[75]
`
`Inventor: Pascal Bruna, ROUGH, France
`
`[73] Assignee: Valois 8A., Le Neubourg, France
`
`[21] Appl. No.:
`
`08/765,104
`
`[22] PCT Filed:
`
`Jun. 9, 1995
`
`[86] PCT No.:
`
`PCT/FR95/00756
`
`§ 371 Date:
`
`Feb- 13, 1997
`
`.
`§ 102(e) Date. Feb. 13, 1997
`[87] PCT Pub. No.: W095/34874
`
`PCT Pub. Date: Dec. 21, 1995
`
`[30]
`
`Foreign Application Priority Data
`
`Jun. 10, 1994
`
`[FR]
`
`France ................................... 94 07114
`
`[51]
`Int. Cl.6 ............................... G06M 1/00; B67D 5/30
`[52] US. Cl. ............................. 235/91 R; 222/18
`
`[58] Field of Search ................................... 235/91 R, 115,
`235/132 R; 222/32, 36, 18
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`165,054
`3,227,127
`3,297,198
`3,454,152
`3,495,567
`3,986,005
`4,041,628
`4,090,354
`4,532,415
`4,565,302
`4,756,423
`4,817,822
`4,890,572
`
`6/1875 Baldwin .
`1/1966 Gayle ...................................... 116/121
`
`1/1967 Wright
`..
`221/5
`7/1969 Immerman et al.
`.
`..... 206/42
`
`2/1970 Hayes et al.
`.........
`116/121
`
`10/1976 Itoh ................ 235/96
`8/1977 Sasson .....
`.. 40/111
`...... 58/117
`5/1978 Schneiter
`.
`
`7/1985 Alway ..........
`235/131 R
`
`1/1986 Pfeiffer et al.
`..... 222/38
`7/1988 Holtsch ........
`206/534
`
`..... 222/38
`4/1989 Rand et al.
`
`1/1990 Huang ..................................... 116/298
`
`4,945,521
`5,261,548
`5,285,427
`5,384,755
`
`5,482,030
`5,718,355
`
`7/1990 Klaus ........................................ 368/21
`..... 215/230
`11/1993 Barker et al.
`
`
`2/1994 Vaucher ................. 368/21
`
`........... 368/35
`1/1995 Feremczy
`
`1/1996 Klein .................................. 128/200.23
`2/1998 Garby et al.
`.............................. 222/36
`
`FOREIGN PATENT DOCUMENTS
`
`0254391
`819885
`1514296
`2103434
`2341166
`48610
`
`.
`
`4/1988 European Pat. Off.
`10/1937
`France .
`2/1968
`France .
`4/1972
`France .
`9/1977
`France .
`9/1889 Germany .
`
`Primary Examiner—Donald Hajec
`Assistant Examiner—Daniel Sherr
`
`Attorney, Agent, or Firm—Sughrue, Mion, Zinn, Macpeak
`& Seas, PLLC
`
`[57]
`
`ABSTRACT
`
`A device for counting doses of substance issued by a
`dispenser for fluids or powders, the device being character-
`ized in that it comprises a first count wheel (10, 110) and a
`second count wheel (20, 120), both count wheels being
`mounted to rotate about a fixed axis of rotation (3, 103), the
`first count wheel (10, 110) comprising a set of teeth (11, 111)
`extending circumferentially about the fixed axis of rotation
`(3, 103) and co-operating with a drive member (30, 130) for
`rotating the first count wheel about the fixed axis of rotation
`on each use of the dispenser, the first count wheel (10, 110)
`further including a drive tongue (14, 114) that is movable
`between a rest position in which it does not co-operate with
`the second count wheel (20, 120), and a drive position in
`which it does co-operate with the second count wheel (20,
`120) to cause it to rotate about the fixed axis of rotation, said
`drive tongue (14, 114) being forced into its drive position by
`cam (8, 108).
`
`22 Claims, 5 Drawing Sheets
`
`131
`
`132
`107
`111
`116
`
`121
`106
`
`151
`
`152
`
`RPC-1007
`
`RPC v Trudell
`
`Page 1 of 13
`
`RPC-1007
`RPC v Trudell
`Page 1 of 13
`
`

`

`US. Patent
`
`N0V.23, 1999
`
`Sheet 1 0f5
`
`5,988,496
`
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`
`RFC-1007 / Page 2 of 13
`
`RPC-1007 / Page 2 of 13
`
`

`

`US. Patent
`
`N0V.23, 1999
`
`Sheet 2 0f5
`
`5,988,496
`
`
`
`52
`
`FIG.5
`
`22
`
`50
`
`20
`
`20
`
`
`
`RFC-1007 / Page 3 of 13
`
`RPC-1007 / Page 3 of 13
`
`

`

`US. Patent
`
`Nov. 23, 1999
`
`Sheet 3 0f 5
`
`5,988,496
`
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`110
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`143
`
`120
`
`165
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`an”.
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`‘‘
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`103
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`140
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`‘717/11/171.‘‘_
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`130
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`114
`
`104
`
`122
`
`\‘\\\\\\\\\\\\\\\L
`
`RFC-1007 / Page 4 of 13
`
`RPC-1007 / Page 4 of 13
`
`
`
`
`
`

`

`US. Patent
`
`N0V.23, 1999
`
`Sheet 4 0f5
`
`5,988,496
`
`131
`
`132
`
`107
`
`111
`
`116
`
`166
`
`121
`
`106
`
`151
`
`152
`
`RFC-1007 / Page 5 of 13
`
`RPC-1007 / Page 5 of 13
`
`

`

`US. Patent
`
`N0V.23, 1999
`
`Sheet 5 0f5
`
`5,988,496
`
`142a
`
`143
`
`141
`
`121
`
`/ 118
`
`120
`
`118
`
`132
`
` 104
`
`FlG.9b
`
`“’3
`
`RFC-1007 / Page 6 of 13
`
`RPC-1007 / Page 6 of 13
`
`

`

`5,988,496
`
`1
`DOSE COUNTER FOR INHALERS
`
`BACKGROUND OF THE INVENTION
`
`The present invention relates to a device for counting
`doses issued by a substance dispenser, and more particularly
`by an inhaler of the kind used, for example, in the field of
`pharmacy.
`In medical applications in particular, it is often necessary
`to spray some particular number of doses of substance
`contained in the dispenser, e.g. on a daily basis. To prevent
`mistakes in handling and/or dosage, it is desirable to provide
`means that serve to display the number of doses that have
`been sprayed, or that remain to be sprayed if the initial
`display gives the maximum number of doses that can be
`displayed (up-counter or down-counter).
`Proposals have already been made, in patent EP-O 269
`496 for a counter that counts actuation of the pushbutton and
`that comprises a count wheel mounted to rotate coaxially
`with the pushbutton and provided with a crown of axially
`extending peripheral teeth. A flexible blade secured to the
`pushbutton drives the wheel causing it to rotate when the
`pushbutton is actuated. That device is simple and cheap, but
`because it has only one wheel it is limited as to number of
`doses that can be counted.
`
`Also, since that device transforms the axial motion of the
`pushbutton into rotary motion of the wheel, it is unsuitable
`for operating independently of the actuating pushbutton.
`An object of the present invention is to provide a device
`for counting doses that is capable of counting an arbitrary
`number of doses (typically several tens to several hundreds
`of doses) and capable of being actuated by a member
`exerting movement in translation.
`SUMMARY OF THE INVENTION
`
`Another object of the present invention is to provide a
`device for counting doses that is capable of counting an
`arbitrary number of doses (typically several tens to several
`hundreds of doses) and that is capable of being actuated by
`a member exerting movement in rotation.
`Another object of the invention is to provide a device for
`counting doses that is intended to count a predetermined
`number of doses and that is adapted to prevent the substance
`dispenser being actuated after said predetermined number of
`doses has been counted.
`
`The present invention thus provides a device for counting
`doses of substance issued by a dispenser for fluids or
`powders, the device being characterized in that it comprises
`a first count wheel and a second count wheel, both count
`wheels being mounted to rotate about a fixed axis of
`rotation, said first count wheel comprising a set of teeth
`extending circumferentially about said fixed axis of rotation
`and co-operating with a drive member for rotating said first
`count wheel about said fixed axis of rotation on each use of
`
`the dispenser, said first count wheel further including a drive
`tongue that is movable between a rest position in which it
`does not co-operate with said second count wheel, and a
`drive position in which it does co-operate with said second
`count wheel to cause it to rotate about said fixed axis of
`
`rotation, said drive tongue being forced into its drive posi-
`tion by cam means.
`More particularly, said second count wheel includes a set
`of teeth disposed circumferentially about said fixed axis of
`rotation and said drive tongue of said first count wheel
`includes a head at one end, said head engaging in said set of
`teeth of said second count wheel when said drive tongue is
`in its drive position.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`Preferably, said first count wheel acts as a units counter
`and includes a peripheral set of teeth containing ten teeth,
`said ten teeth being uniformly distributed around said fixed
`axis, and each time said first count wheel has performed a
`complete revolution about said fixed axis of rotation said
`drive tongue co-operates with said cam means to rotate said
`second count wheel which acts as a tens counter.
`
`Advantageously, there are provided a first locking device
`acting on the first count wheel to prevent it from returning
`in the direction opposite to the direction of rotation imposed
`by said drive element, and a second locking device acting on
`said second count wheel to prevent it from rotating in the
`direction opposite to the direction of rotation imposed by
`said drive tongue of said first count wheel.
`More particularly, said second locking device comprises
`a flexible leg secured to said second count wheel and
`provided at
`its one of its ends with a stud, said stud
`co-operating with a grooved profile that is fixed relative to
`the axis of rotation to prevent said second count wheel from
`rotating in either direction when said drive tongue of said
`first count wheel is in its rest position. Any rotation of the
`second count wheel because of possible friction is thus
`avoided.
`
`Advantageously, said fixed grooved profile which coop-
`erates with said stud of said flexible leg of said second
`locking device includes fixed abutment means locking said
`stud of said flexible leg, thus preventing rotation of said
`second count wheel, the maximum number of doses issued
`by the dispenser thus being determined by the number of
`grooves in the grooved profile situated ahead of said abut-
`ment means.
`
`Thus, a second count wheel having five teeth restricts the
`number of doses issued to forty-nine, whereas with twenty
`teeth the maximum number of doses issued would be one
`
`hundred ninety-nine.
`In a first embodiment of the invention, a rod is mounted
`in fixed manner on said fixed axis of rotation and the first and
`
`second count wheels are substantially annular and are
`mounted to rotate on said fixed rod, said first count wheel
`having a peripheral set of teeth extending circumferentially
`about said fixed axis with the teeth thereof being outwardly
`directed, said set of teeth co-operating with a drive member
`secured to an actuator pushbutton of the dispenser and
`exerting movement
`in translation, said drive element
`co-operating on each actuation of the pushbutton with a
`tooth of said set of teeth to cause said first count wheel to
`rotate about said fixed axis or rotation.
`
`Preferably, there is provided a first locking device includ-
`ing a fixed flexible blade which co-operates with the set of
`teeth of said first count wheel to prevent it from rotating in
`the direction opposite to the direction of rotation imposed by
`said drive member.
`
`In the first embodiment of the invention, said first count
`wheel includes a drive tongue which extends circumferen-
`tially about said fixed axis of rotation and which includes a
`head at one end, the head being radially movable between a
`rest position in which said head extends radially inwards
`beyond the outer annular surface of the first count wheel,
`and a drive position in which the head co-operates with said
`second count wheel, said cam means being fixed relative to
`said axis of rotation and being disposed without friction
`substantially against said outer annular surface of said first
`count wheel level with said drive tongue to force said head
`of said drive tongue into its drive position each time said first
`count wheel has performed one complete revolution about
`said fixed axis of rotation.
`
`RFC-1007 / Page 7 of 13
`
`RPC-1007 / Page 7 of 13
`
`

`

`5,988,496
`
`3
`Also, said second count wheel preferably includes a set of
`teeth extending circumferentially about said fixed axis of
`rotation and facing outwardly, said set of teeth being dis-
`posed radially inside said drive tongue of said first count
`wheel in such a manner that when said head of the tongue
`is in its drive position it engages in a tooth of said set of teeth
`to drive said second count wheel to rotate about said fixed
`axis of rotation. If said set of teeth of the second count wheel
`
`has only a few teeth (e.g. five), then it naturally occupies
`only a fraction of the circumference of said second count
`wheel.
`
`10
`
`the outside of said head of the drive
`Advantageously,
`tongue has a profile complementary to the profile of said
`fixed cam means, and the inside of said head has a profile
`that is complementary to the profile of said teeth of said set
`of teeth of the second count wheel.
`
`In a second embodiment of the invention, said first count
`wheel includes a first set of teeth extending circumferen-
`tially about said fixed axis of rotation and having its teeth
`inwardly directed and uniformly distributed around said
`fixed axis to co-operate with a drive member exerting rotary
`movement, said drive member being actuated by the user by
`means of an actuator knob that is movable in rotation about
`
`the axis of rotation between first and second extreme posi-
`tions.
`
`Preferably, said drive member is annular, and mounted to
`rotate about said fixed axis of rotation, and includes an
`annular flexible arm movable radially between a rest posi-
`tion in which a projecting portion of said arm extends
`radially outwards beyond the annular outer surface of said
`arm, and a drive position in which said projecting portion of
`the arm co-operates with a tooth of said first set of teeth of
`said first count wheel to drive it in rotation, said flexible arm
`being forced into its drive position by the actuator knob.
`Advantageously, said actuator knob is annular and is
`mounted to rotate about said fixed axis of rotation in such a
`manner as to surround said drive member, said actuator knob
`including means for rotating said drive member about said
`fixed axis of rotation, and means for forcing said arm into its
`drive position.
`In particular, said means for forcing said arm into its drive
`position include a swelling disposed on the inner annular
`face of said actuator knob, and said means for rotating the
`drive member include two projections which co-operate
`with said drive member, both projections being disposed at
`the same height on the inner annular face of said actuator
`knob, the first projection being adapted to cause the drive
`member to rotate in one direction to bring the projecting
`portion of its arm face to face with a tooth of said first set
`of teeth, and the second projection being adapted to drive the
`drive member in the other direction to rotate said first count
`
`wheel when the flexible arm is in its drive position.
`More precisely, said first set of teeth of said first count
`wheel has ten teeth, the angular distance between the two
`extreme positions of the actuator knob being about 180°, and
`said projections being disposed so as to be angularly spaced
`apart by about 144°, said actuator knob being initially
`rotated through 180° in one direction towards its second
`extreme position to bring said projecting portion of the arm
`of the drive member face to face with the next tooth in the
`
`first set of teeth and then being returned to its first extreme
`position by being rotated in the opposite direction,
`the
`second projection rotating said drive member, and said arm
`is forced into its drive position to cause said first count wheel
`to rotate about the axis of rotation.
`
`In this second embodiment of the invention, said counter
`device further includes a full stroke device preventing said
`
`15
`
`20
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`25
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`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`actuator knob from being returned to its initial position
`unless it has previously been rotated as far as its stop means,
`so as to ensure that said projecting portion of said arm is
`properly positioned facing a tooth of said first set of teeth.
`Optionally, said full stroke device comprises a fixed plate
`secured to said fixed axis of rotation and supporting a
`substantially annular rail extending circumferentially about
`said axis of rotation through about 180°, and a pawl pro-
`vided with a flexible finger, said pawl being constrained to
`rotate with said actuator knob, said flexible finger being
`constrained in the initial position of the actuator knob to pass
`inside said rail, said rail including a rack co-operating with
`said flexible finger to prevent said actuator knob rotating in
`an opposite direction, said flexible finger exiting said rail at
`an end thereof to enable said actuator knob to return to its
`
`initial position. Advantageously, said end of said rail forms
`stop means defining the second extreme position of said
`actuator knob.
`
`Preferably, said first count wheel includes a second set of
`teeth extending circumferentially about said fixed axis of
`rotation and having its inwardly extending teeth uniformly
`distributed about said fixed axis of rotation to co-operate
`with a first locking device secured to a fixed tubular element
`fixedly mounted on said fixed axis of rotation and including
`at least one flexible element preventing said first count
`wheel from rotating in the direction opposite to the direction
`of rotation imposed by said drive member.
`In the second embodiment of the invention, said drive
`tongue extends circumferentially about said fixed axis of
`rotation, its inner surface approximately forming an annular
`surface, and includes at one end a head that is radially
`movable between a rest position in which the head extends
`radially inwards beyond said inner annular surface and a
`drive position in which said head cooperates with said
`second count wheel, said cam means being secured to said
`fixed tubular element and disposed without significant fric-
`tion against said inner annular surface of said drive tongue
`to force the head of said tongue into its drive position
`whenever said first count wheel has performed a complete
`revolution about said axis of rotation.
`
`Advantageously, said second count wheel includes a set of
`teeth extending circumferentially about said fixed axis of
`rotation and directed inwardly, said set of teeth being
`disposed radially outside said drive tongue of said first drive
`wheel in such a manner that in its drive position said head
`of the tongue engages in one of the teeth of said set of teeth
`to drive said second count wheel in rotation about said fixed
`axis of rotation.
`
`the first and second count wheels include
`Preferably,
`display means on their respective outer peripheral surfaces.
`BRIEF DESCRIPTION OF THE FIGURES
`
`Other characteristics and advantages of the present inven-
`tion appear from the following detailed description of two
`embodiments given by way of non-limiting example and
`with reference to the accompanying drawings.
`In the drawings:
`FIG. 1 is a diagrammatic cross-section view of a counter
`device constituting a first embodiment of the invention;
`FIG. 2 is a cross-section view on a plane perpendicular to
`the section of FIG. 1, showing the FIG. 1 counter device;
`FIG. 3 is a perspective view of the first count wheel of the
`device shown in FIGS. 1 and 2;
`FIGS. 4a and 4b are perspective views in two different
`directions of the second count wheel of the device of FIGS.
`1 and 2;
`
`RFC-1007 / Page 8 of 13
`
`RPC-1007 / Page 8 of 13
`
`

`

`5,988,496
`
`5
`FIG. 5 is a diagrammatic horizontal section through the
`second non-return device in the first embodiment;
`FIG. 6 is a diagrammatic cross-section view through a
`counter device constituting a second embodiment of the
`invention;
`FIG. 7 is an exploded view of the FIG. 6 device;
`FIG. 8 is a cross-section view of the device of FIGS. 6 and
`
`7 on a plane perpendicular to the section of FIG. 6 and
`showing, in particular, the first count wheel; and
`FIGS. 9a and 9b are cross-section views similar to that of
`
`FIG. 8 showing the second count wheel respectively with the
`driving tongue in its rest position and in its driving position.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`FIGS. 1 to 5 show a first embodiment of the counter
`
`device of the invention which is adapted to count actuations
`of the pushbutton of a substance dispenser.
`In this
`embodiment, the device transforms a translation movement
`of the pushbutton into a rotary movement of the count
`wheel(s).
`The counter device comprises a first count wheel 10 and
`a second count wheel 20. According to the invention, these
`two count wheels 10 and 20 are mounted to rotate about a
`
`common fixed rotary axis 3, a rod 4 being mounted in fixed
`manner along said rotary axis 3 to support said count wheels.
`Advantageously, the fixed rod 4 may include securing means
`5 at its end to prevent any translational displacement of said
`count wheels 10, 20 along said rod 4.
`According to the invention, the first count wheel 10 has a
`set of teeth 11 disposed circumferentially about said axis of
`rotation 3. As shown in FIGS. 1 and 3, said count wheel 10
`is preferably substantially annular and said set of teeth 11
`lies on its periphery with the teeth extending outwards. Thus,
`the teeth 11 can co-operate with a drive member 30 disposed
`tangentially to said first wheel 10 and, for example, secured
`to the pushbutton of the dispenser (not shown). This drive
`member 30 advantageously includes an end 31 of shape
`adapted to engage in a tooth of said set of teeth 11.
`Preferably, said set of teeth 11 comprises exactly ten teeth,
`and the first count wheel 10 thus acts as a units counter.
`
`As shown in FIGS. 1 and 3, the teeth of said set 11 are all
`identical and each comprises a sloping bottom wall 12
`extending approximately circumferentially relative to the
`axis of rotation 3 and an abutment wall 13 that is approxi-
`mately perpendicular to said bottom wall 12 and thus
`extends approximately radially relative to said axis 3. In
`operation, the end 31 of the drive member 30 engages along
`said bottom wall 12 in the direction of arrow A of FIG. 1 so
`
`as to come into abutment against the abutment wall 13,
`thereby rotating the first count wheel 10 about the axis of
`rotation 3 by exerting thrust on said abutment wall 13. When
`the pushbutton (not shown) and thus the drive member 30
`return to their rest position, the end 31 of said drive member
`slides along said bottom wall 18 in the direction opposite to
`arrow A and takes up a position facing the next tooth in said
`set 11. Advantageously,
`the end 31 is resilient so as to
`provide little resistance, e.g. due to friction, as the drive
`member 30 returns to its rest position. The drive member 30
`is preferably disposed in such a manner that on each
`actuation it causes the first count wheel 10 to rotate through
`an angle corresponding to exactly one tooth of the set 11.
`In order to prevent the first count wheel 10 from being
`rotated backwards due to possible friction against said end
`31 of the drive member 30 against the bottom wall 12 of one
`
`10
`
`15
`
`20
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`25
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`30
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`35
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`40
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`45
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`50
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`55
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`60
`
`65
`
`6
`of the teeth of the set of teeth 11 while the drive member 30
`
`is returning to its rest position, a first locking device 6 is
`provided that acts on the set of teeth 11.
`The locking device advantageously comprises a flexible
`blade 6 that is fixed relative to said axis of rotation 3, with
`the end 7 thereof engaging in the set of teeth 11. Because
`said blade 6 is flexible, when the wheel 10 is rotated by the
`drive member 30, it slides over the bottom wall 12 of the
`tooth with which it is engaged and clicks into the following
`tooth.
`
`This click action can present several advantages.
`Firstly, because of the flexibility of the blade, it makes a
`small noise which is useful in informing the user that the
`count wheel 10 has been advanced by one unit. Secondly, in
`powder inhalers where the dose of substance drops into the
`metering chamber under gravity, the clicking of the blade 6
`generates a small amount of vibration that can favor refilling
`of said metering chamber.
`Naturally, by pressing against the abutment wall 13 of the
`corresponding tooth and as can be seen clearly in FIG. 1, the
`end 7 of the blade 6 prevents the count wheel 10 from
`returning in the direction opposite to the direction of rotation
`imparted by the drive member 30.
`The first count wheel 10 also includes its own drive
`
`tongue 14 for rotating the second count wheel 20. This
`tongue 14 preferably extends circumferentially about said
`fixed axis of rotation 3 and it is movable radially between a
`rest position and a drive position. Advantageously,
`this
`mobility is provided by said tongue 14 being somewhat
`flexible.
`
`the drive tongue extends over a
`As shown in FIG. 3,
`fraction of the periphery of the first count wheel 10 and it
`includes a head 15 at one of its ends. In the rest position of
`the tongue 14 its head 15 extends radially outwards beyond
`the outer annular surface 18 of said first count wheel 10 and
`
`it does not co-operate with the second count wheel 20. In the
`drive position of the tongue 14, its head 15 co-operates with
`said second wheel 20 to rotate it about said axis of rotation
`3.
`
`According to the invention, the tongue 14 is forced into its
`drive position by cam means 8. The cam means 8 is
`preferably fixed relative to the axis of rotation 3 and may
`advantageously be secured to the rod 4 which supports both
`count wheels 10 and 20. It is disposed substantially without
`friction against said outer annular surface 18 of the first
`count wheel, and specifically level with the drive tongue 14.
`Thus, each time the first count wheel performs one complete
`revolution about the axis of rotation 3, the head 15 of the
`tongue goes past said cam means 8 and is forced into its
`drive position. In the embodiment shown in the FIGS. 1 and
`2, the cam means 8 has a rounded profile facing the tongue
`14 and matching the outer annular surface 18 of the first
`count wheel 10, said profile extending over a length that
`corresponds to about the angular length of one tooth of the
`set of teeth 11. The head 15 of the drive tongue 14 has a
`profile on its outside that is complementary to that of said
`cam means 8, and on its inside it has a profile that is
`complementary to the teeth of the set of teeth 11. It is thus
`ensured that the drive tongue 14 is forced into its drive
`position once only during each complete revolution of the
`first counting tooth wheel 10, and that this occurs only over
`an angular distance corresponding to one of the ten teeth in
`the set 11. The first count wheel 10 thus properly performs
`its function of counting units.
`The second count wheel 20 is shown in detail in FIGS. 4a
`
`and 4b. It is generally substantially annular in shape and, like
`
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`5,988,496
`
`7
`the first wheel 10, it is engaged on the fixed rod 4 about
`which it can rotate, but along which it is not free to slide.
`According to the invention, this second count wheel 20 has
`a set of teeth 21 disposed circumferentially relative to the
`axis of rotation 3. Advantageously, this set of teeth 21 is
`offset radially inwards towards the axis of rotation 3 such
`that when mounted on said fixed rod 4, said set of teeth 21
`of the second count wheel 20 is disposed radially inside said
`drive tongue 14 of the first count wheel. Preferably, both
`wheels rotate relative to each other with a small amount of
`friction. Thus, when the head 15 of the drive tongue 14 is
`forced radially into its driving position, it engages with one
`of the teeth of said set of teeth 21 of the second count wheel
`20 so as to rotate it. Advantageously, the teeth of said second
`set of teeth 21 are substantially similar in shape to the teeth
`of the first wheel 10 so as to co-operate effectively with the
`head 15 of the tongue 14. Preferably,
`the angular offset
`between two successive teeth of said set of teeth 21 of the
`second wheel 20 is identical to the angular offset between
`two successive teeth in the set 11 of the first wheel 10. In this
`way, on each revolution, the driving tongue 14 in its driving
`position serves to advance the second count wheel 20 by
`exactly one tooth. The second wheel 20 thus acts as a tens
`counter while the first wheel 10 acts as a units counter.
`
`the second count wheel 20 from
`In order to prevent
`rotating in the direction opposite to the direction in which it
`is rotated by said drive tongue 14 of the first count wheel 10,
`a second locking device is provided. Advantageously, said
`locking device comprises a locking plate 50 that is fixed
`relative to the axis of rotation 3, said locking plate 50 being
`designed to co-operate with a stud 22 integral with the
`second count wheel 20. Said locking plate 50 preferably
`supports a grooved profile 51 with grooves that extend
`circumferentially about axis of rotation 3. As shown in FIG.
`5,
`the groove profile 51 may face inwards, but it could
`equally well face outwards. In addition, the grooves shown
`in FIG. 5 are similar in shape to the teeth, but they could
`have any other shape suitable for releasably retaining said
`stud 22 of the second count wheel 20. Thus, the grooved
`profile 51 not only prevents the second count wheel 20 from
`rotating in the direction opposite to the direction of rotation
`imposed by the tongue 14, but it also prevents any rotation
`in the direction of rotation imposed by the tongue 14 while
`said tongue is in its rest position. Such friction as may exist
`between the first and second count wheels 10 and 20
`
`therefore does not give rise to rotation of the second count
`wheel 20. Advantageously, said grooved profile 51 has a
`number of grooves identical to the number of teeth in the set
`of teeth 21 of the second count wheel 20. At
`its end
`
`corresponding to the last groove, it may also include abut-
`ment means 52 preventing said stud 22 from rotating, and
`consequently preventing the second wheel 20 from continu-
`ing its rotation. When the second wheel 20 can no longer
`rotate, it locks the first wheel 20 at the moment when the
`tongue 14 is forced into its drive position. If, as is preferable,
`dose counting is driven by actuating the dispenser, then said
`abutment means 52 also locks actuation of the dispenser.
`The maximum number of doses that can be issued by the
`dispenser is thus determined by the number of grooves in
`said grooved profile 51 situated ahead of said abutment
`means 52 (in the direction of rotation corresponding to
`counting). The stud 22 secured to the second count wheel 20
`is preferably fixed at the end of a flexible leg 23 of said
`second wheel which extends circumferentially about the axis
`of rotation 3. Because of the radial flexibility of the leg 23,
`the stud 22 can thus be urged towards the following groove
`of the grooved profile 51 while the second wheel 20 is being
`rotated by the drive tongue 14 of the first wheel 10.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`8
`The first and second count wheels preferably include
`display means such as digits enabling the user
`to be
`informed either of the number of doses that have been issued
`or else of the number of doses that remain to be issued.
`
`Advantageously, this display is situated on the outer periph-
`eral surfaces 16 and 26 of the first and second count wheels
`
`10 and 20 respectively. Thus, the first count wheel 10 has the
`digits 0 to 9 distributed around its periphery with each digit
`corresponding to one tooth in the set 11. In the example
`shown in FIGS. 1 to 5, the second count wheel has five teeth,
`and the maximum number of doses that the dispenser can
`issue is thus forty-nine. It is naturally possible to fix some
`other maximum number of doses by providing a different
`number of teeth for the second count wheel.
`FIGS. 6 to 9 show a second embodiment of the invention.
`This second embodiment relates to a counter device which
`
`is actuated by means of a drive member that exerts rotary
`movement. For example, there exist inhalers comprising a
`compressed air mechanism for expelling doses of substance
`from the metering chamber, said metering chamber being
`filled by rotary filling means. In this case, the filling of the
`metering chamber is not directly tied to actuating the expul-
`sion mechanism.
`
`Since the expulsion mechanism can be actuated only after
`the metering chamber has indeed been filled, it is advanta-
`geous in this kind of dispenser to count the number of times
`the metering chamber has been filled.
`The counter device of this second embodiment of the
`
`invention comprises first and second count wheels 110 and
`120 mounted to rotate freely about a fixed axis of rotation
`103.
`
`Advantaously, a fixed tubular element 104 is mounted
`along said axis of rotation 103 to support both count wheels
`110 and 120 so that they can rotate freely. As described for
`the first embodiment, the first count wheel 110 is rotated
`about the fixed axis of rotation 103 by a drive member 130
`which co-operates with a first set of teeth 111 of said first
`wheel 110. This first set of teeth 111 extends circumferen-
`
`tially around said axis of rotation 103 and comprises exactly
`ten teeth when the first wheel 110 acts as a units counter.
`
`the teeth of this first set 111 are all
`Advantageously,
`identic