`Klitgaard et al.
`
`USOO6582404B1
`(10) Patent No.:
`US 6,582,404 B1
`(45) Date of Patent:
`*Jun. 24, 2003
`
`(54) DOSE SETTING LIMITER
`
`(75) Inventors: Peter Christian Klitgaard, Smørum
`(DK); Steffen Hansen, Hillerød (DK);
`Bo Radmer, Hillerød (DK); Claus
`Schmidt Moller, Fredensborg (DK)
`(73) Assignee: NNA/S, Bagsvaerd (DK)
`(*) Notice:
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 137 days.
`This patent is Subject to a terminal dis
`claimer.
`
`(21) Appl. No.: 09/655,922
`(22) Filed:
`Sep. 6, 2000
`Related U.S. Application Data
`(60) Provisional application No. 60/155,612, filed on Sep. 23,
`1999.
`Foreign Application Priority Data
`(30)
`Sep. 16, 1999
`(DK)........................................ 1999 O1309
`(51) Int. Cl." ......................... A61M 5700; A61M 5/178;
`A61M 5/135
`(52) U.S. Cl. ....................... 604/181; 604/186; 604/207;
`604/208; 604/211; 604/224
`(58) Field of Search ................................. 604/181, 186,
`604/207, 208, 211, 224
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`5,947,934. A * 9/1999 Hansen et al. .............. 604/207
`FOREIGN PATENT DOCUMENTS
`
`12/1998 ............ A61MAS/24
`DK PCT WO 98/56436
`EP
`O 879 610 A2 11/1998
`WO
`WO 89/07463
`8/1989
`
`
`
`WO
`WO
`WO
`
`10/1991
`WO 91/14467
`4/1993
`WO 93/07922
`3/1998
`WO 98/10813
`OTHER PUBLICATIONS
`
`Hansen et al., Injection Device, a Preassembled Doses
`Setting and Injection Mechanism for an Injection Device,
`and a Method of Assembling an Injection Device, May 1,
`2001.*
`
`* cited by examiner
`
`Primary Examiner William C. Doerrler
`Assistant Examiner Filip Zec
`(74) Attorney, Agent, or Firm Marc A. Began, Esq.;
`Richard W. Book, Esq.; Reza Green, Esq.
`(57)
`ABSTRACT
`A limiting mechanism which prevents the Setting of a dose,
`which exceeds the amount of liquid left in a cartridge of an
`injection device, is disclosed. The injection device is the
`type where a dose is Set by rotating a dose Setting member
`relative to a driver and away from a fixed Stop in the
`injection device. The dose Setting member interfaces the
`driver Such that the dose Setting member can be rotated in
`one direction without rotating the driver. The dose is injected
`by rotating back the dose Setting member which during the
`backward rotation carries the driver with it. Rotating the
`driver causes the piston rod to move forward inside the
`cartridge and expel Some of the liquid contained in the
`cartridge. The driver is provided with a track having a length
`which is related to the total amount of liquid in the cartridge
`and which track is engaged by a track follower coupled to
`the dose setting member to follow rotation of this dose
`Setting member. Each time a dose is Set and injected, the
`track follower moves further into the track. When the track
`follower reaches the end of the track the dose Setting
`member can not be rotated further, and a dose larger than the
`remaining liquid in the cartridge cannot be Set.
`
`4 Claims, 2 Drawing Sheets
`
`PFIZER, INC. v. SANOFI-AVENTIS DEUTSCHLAND GMBH
`
`Ex. 1017, p. 1 of 6
`
`
`
`U.S. Patent
`
`Jun. 24, 2003
`
`Sheet 1 of 2
`
`US 6,582,404 B1
`
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`PFIZER, INC. v. SANOFI-AVENTIS DEUTSCHLAND GMBH
`
`Ex. 1017, p. 2 of 6
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`U.S. Patent
`
`Jun. 24, 2003
`
`Sheet 2 of 2
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`US 6,582,404 B1
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`PFIZER, INC. v. SANOFI-AVENTIS DEUTSCHLAND GMBH
`
`Ex. 1017, p. 3 of 6
`
`
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`1
`DOSE SETTING LIMITER
`
`US 6,582.404 B1
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`This application claims priority under 35 U.S.C. 119 of
`U.S. provisional application No. 60/155,612 filed on Sep.
`23, 1999 and Danish application no. PA 1999 01309 filed on
`Sep. 16, 1999, the contents of which are fully incorporated
`herein by reference.
`FIELD OF THE INVENTION
`The present invention relates to injection devices wherein
`the contents of a cartridge are injected as a number of
`individually Set doses.
`Such devices have a dose Setting mechanism by which the
`doses are Set for Subsequent injecting when an injection
`button is operated. This can be obtained by moving a carrier
`along a piston rod a distance proportional to the wanted dose
`and Subsequently moving the carrier back to its original
`position So that the carrier carries the piston rod with it
`instead of being moved along Said piston rod.
`
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`15
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`SCOPE OF THE RELATED ART
`From EP 327 910 is known a syringe by which a dose is
`Set by Screwing a nut member up along a threaded piston rod
`away from a stop in a housing. The Set dose is injected by
`pressing the end of the nut member that forms an injection
`button whereby the nut member is moved back to abutment
`with the Stop again. During the latter movement of the nut
`member the piston rod is carried along by the nut that does
`not move relative to this piston rod during the injection.
`When a dose is Set it is convenient if a limiting device is
`provided which makes it impossible to Set a dose that
`exceeds the amount of medicament which is left in the
`cartridge. In EP 327 910 this is obtained by the fact that the
`thread of the piston rod has Such a length that the cartridge
`is just emptied when the nut is Screwed to the end of the
`thread and then pressed home to its abutment with the Stop.
`By Setting a dose the nut can only be Screwed to the end of
`the thread and thereby the size of the last dose is limited to
`comprise the remaining amount in the cartridge.
`The distance the injection button has to be moved corre
`sponds to the distance the piston in the cartridge has to be
`moved to inject the Set dose. Especially by larger cartridges
`with a large croSS Section diameter this distance can be very
`Short. To obtain a larger movement of the injection button a
`Sort of gearing may be used So that the distance the injection
`button has to be moved is proportional with the injected dose
`but is a number of times the movement of the piston in the
`cartridge.
`EP 608 343 describes an example of such a geared dose
`Setting and injection mechanism. In this device the carrier
`does not cooperate directly with the threaded piston rod but
`with a driver element which can move the piston rod when
`a Set dose is injected. In this device the driver element
`comprises a nut member which is fixed against axial dis
`placement in the injection device. The thread of the nut
`member engages an outer thread of the piston rod which is
`Secured against rotation in the injection device. By the
`Setting of a dose the carrier is rotated away from a stop to
`which it is returned when the injection button is operated.
`During its return the carrier rotates the driver element that
`moves the piston rod further into the cartridge to press the
`piston of this cartridge So that a set amount of the medica
`ment in the cartridge is pressed out through an injection
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`needle at the distal end of the cartridge. AS the nut member
`is not moved relative to the piston rod during the Setting of
`a dose, a limiting construction as described above cannot be
`provided limiting the dose So it does not exceed the amount
`of liquid left in the injection device.
`
`OBJECT AND SUMMARY OF THE INVENTION
`An object of the invention is to provide a limiting mecha
`nism which prevents Setting of a dose that exceeds the
`amount of liquid left in a cartridge of an injection device of
`the geared type wherein a dose is set by rotating a dose
`Setting member relative to a driver and away from a fixed
`Stop in the injection device, and the dose is injected by
`rotating back the dose Setting member which during this
`rotation carries the driver element with it to rotate this driver
`element which moves the piston rod forward.
`Such a mechanism is according to the invention charac
`terized in that the driver element is provided with a track
`having a length which is related to the total amount of
`medicament in the cartridge and which track is engaged by
`a track follower coupled to the dose Setting member to
`follow rotation of Said dose Setting member. During the
`setting of a dose the track follower will be advanced in the
`track of the driver to a position depending on the Set dose as
`during dose Setting the dose Setting member and the driver
`are rotated relative to each other. AS during the injection the
`driver follows the rotation of the dose setting member, the
`pin of the dose Setting member will keep its position in the
`track of the driver when the set dose is injected. The length
`of the track is So adapted that the pin reaches the end of the
`track and makes an increase of the Set dose impossible when
`a dose is Set which corresponds to the amount of liquid
`remaining in the cartridge.
`According to the invention the driver may be disk shaped
`and have a spiral shaped track which is engaged by a cam on
`a member which is flexibly coupled to the dose setting
`member so that the pin can be moved radially when it
`follows the track of the driver.
`In another embodiment of the invention the driver may be
`cylindrical and have a helical track which is engaged by a
`cam on the dose Setting member which is a cylinder con
`centric with the driver.
`The track may be provided as a thread in the driver and
`the track follower may be a nut shaped member coupled to
`the dose Setting member and provided with a thread engag
`ing the thread of the driver. When a dose is set the dose
`Setting member is Screwed with its thread along the thread
`of the driver. The limitation of the set dose is obtained by
`giving the threads an appropriate length.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`In the following the invention will be explained in further
`details with references to the drawing, wherein
`FIG. 1 shows an exploded view of a syringe with a dose
`limiter according to the invention;
`FIG.2 shows an enlarged view of the dose Setting element
`and the driver element of the syringe in FIG. 1; and
`FIG.3 shows the dose setting member, the driver, and the
`track follower of another embodiment of an injection
`Syringe.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`The Syringe in FIG. 1 comprises a housing 1 accommo
`dating a cartridge 2 from which the content can be pressed
`
`PFIZER, INC. v. SANOFI-AVENTIS DEUTSCHLAND GMBH
`
`Ex. 1017, p. 4 of 6
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`3
`out by a piston rod 3 which is by injection via gear wheels
`4 and 5 advanced a distance corresponding to a dose Set by
`dose Setting. A dose Setting member 6 is provided with a
`toothed wheel 7 surrounding a central bore through which a
`pinion 8 on a driver 9 projects as it is shown in FIG. 2. The
`dose Setting element 6 is operated through an operation
`element 10 which has a finger grip 11, a carrier 12 which
`engages the dose Setting member 6, and a arrow 13 pointing
`on a scale 14 provided on a lid 15 which forms a part of the
`housing 1. FIG. 1 further shows a cap 25 which can be put
`on to protect a not shown needle which may be mounted on
`the Syringe, and an injection button 16 which is sliding
`mounted in the housing 1 and which has a recess 17 which
`is on one of its side Surfaces provided with a cogging 18.
`In the assembled syringe the toothed wheel 7 on the dose
`Setting member 6 engages the cogging 18 of the button
`element 16 whereas the pinion 8 on the driver 9 engages the
`part with the large diameter of the gear wheel 5 the part of
`which with the Small diameter engages the other gear wheel
`4 which further engages a cogging 19 on the piston rod 3.
`The driver member 9 is provided with pawl 26 which with
`not shown teeth in the housing forms an unidirectional
`coupling allowing the driver 9 to rotate only in the direction
`by which the piston rod 3 is advanced into the cartridge 2.
`A ratchet is provided by Sawtooth shaped protrusions on the
`dose Setting element 6 engaging a saw tooth cogging 27 at
`the perimeter of the driver 9, this ratchet being so oriented
`that only rotation of the dose setting member 6 in the
`direction in which the driver 9 can move is transmitted from
`the dose setting member 6 to the driver 9. By rotation of the
`dose Setting member 6 in the opposite direction the teeth of
`the ratchet parts will ride over each other.
`To Set a dose the finger grip 11 of the operation element
`10 is gripped and the element 10 is rotated clockwise until
`the arrow points at the wanted dose on the Scale 14. AS
`mentioned this rotation will make the ratchet parts of the
`dose Setting element and the driver ride over each other. If
`the dose Setting member 6 is rotated in the clockwise
`direction to reduce the Set dose, the ratchet will cause
`transmission of the rotation from the dose Setting member 6
`to the driver 9, but the when a torque in this direction is
`transmitted from the operating element through the carrier
`12 to the dose Setting member 6, this dose Setting member
`is deformed So that the protrusion on the dose Setting
`member 6 is drawn out of its engagement with the toothing
`27 of the driver 9 and an anticlockwise rotation of the dose
`Setting member 6 is allowed without the rotation being
`transmitted to the driver 9.
`Due to the engagement between the toothed wheel 7 on
`the dose Setting member 6 and the cogging 18 of the
`injection button 16 this button will be lifted from the end of
`the housing 1 when a dose is set and will be lowered when
`a dose is reduced.
`When the injection button 16 is pressed to inject a set dose
`the engagement between the toothed wheel 7 on the dose
`Setting member 6 and the cogging 18 of the injection button
`16 will cause the dose Setting member 6 to rotate in an
`anticlockwise direction. AS the torque is not transmitted to
`the dose setting member 6 by the operating element 10, the
`ratchet coupling between the dose Setting member 6 and the
`driver 9 will be active and the driver 9 will be rotated with
`the dose Setting member 6 in the anticlockwise direction and
`will drive the piston rod 3 into the cartridge.
`As it is seen in FIG. 2 the disk shaped driver 9 has in its
`Side facing the dose Setting member 6 a Spiral shaped track
`20 which is engaged by a cam 21 provided at the end of an
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`US 6,582.404 B1
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`4
`arm 22 which is by a flexible beam 23 fastened to the dose
`Setting member 6 So that the arm 22 can Swing to let the cam
`21 move in the radial direction of the driver 9. When the
`dose Setting member 6 during the Setting of a dose is rotated
`relative to the driver 9 the cam is moved along the track 20
`whereas the cam during the injection due to the concomitant
`rotation of the dose setting member 6 and the driver 9
`remains in its position in the track 20 obtained during the
`dose Setting. This way the position of the cam in the track
`reflects the total amount of medicine administered. When the
`cam 21 abuts the end wall 24 of the track 20 the set dose
`cannot be increased and by adapting the length of the track
`to the total amount of medicine in the cartridge it is ensured
`that a dose larger than the amount of medicine remaining in
`the cartridge cannot be set.
`FIG. 3 shows a dose setting member 30 surrounding a
`driver 31 of another embodiment of a dose setting limiter.
`The dose setting member 30 is cylindrical and is on its outer
`wall provided with a helical track 29 which is designed to
`co-operate with a helical inner ridge in a not shown housing
`so that the dose setting member 30 is screwed outward in
`Said housing when rotated to Set a dose and inward in Said
`housing when rotated to reduce a too large Set dose. During
`the dose Setting rotation the dose Setting member 30 is
`rotated freely relative to the driver 31 which it surrounds.
`Between the dose setting member 30 and the driver 31 a nut
`member 32 is coupled which can when it is rotated relative
`to the driver 31 be screwed up along this driver which is at
`its outer surface provided with a helical track 33. At its outer
`wall the nut member 32 is in the axial direction provided
`with a recess 34 which is engaged by a ridge 35 in the axial
`direction on the inner side of the dose setting element 30.
`During the Setting of a dose the nut member 32 is due to
`the engagement between the ridge 35 and the receSS 34
`rotated with the dose setting member 30 relative to the driver
`31 so that the position of the nut member 32 on this driver
`is dependent on the dose set. When the dose is injected by
`pressing a not shown injection button which is placed in an
`end part 36 of the dose setting member 30 this button presses
`a flange 37 at an end of the driver 31 into engagement with
`coupling teeth 38 at the bottom of the end part 36 of the dose
`setting member 30. On its lower not visible side the flange
`37 is provided with coupling teeth corresponding to the
`coupling teeth 38 of the dose setting member 30 and when
`the dose Setting member 30 is due to the engagement
`between the track 29 in the dose setting member 30 and the
`ridge in the housing forced to rotate relative to the housing
`when it is pressed into the housing the rotation will be
`transmitted to the driver 31 which due to the engaging
`coupling teeth is forced to rotated with the dose Setting
`member and during this rotation the nut member 32 will
`maintain its position on the driver 31. This way the position
`of the nut member 32 on the driver 31 will always indicate
`the total sum of set and injected doses. When the length of
`the helical track 33 in the driver 31 is adapted to the amount
`of medicine in a cartridge the nut member 32 will reach the
`end of the track 33 and Stop for Setting a dose larger than the
`amount remaining in the cartridge.
`What is claimed is:
`1. A limiting mechanism that prevents Setting of a dose
`that exceeds the amount of liquid left in a cartridge of an
`injection device wherein a dose is set by rotating a dose
`Setting member relative to a driver and away from a fixed
`Stop in the injection device, and the dose is injected by
`rotating back the dose Setting member which during this
`rotation carries the driver with it to rotate this driver which
`moves the piston rod forward, wherein the driver is provided
`
`PFIZER, INC. v. SANOFI-AVENTIS DEUTSCHLAND GMBH
`
`Ex. 1017, p. 5 of 6
`
`
`
`US 6,582.404 B1
`
`S
`with a track having a length which is related to the total
`amount of medicament in the cartridge and which track is
`engaged by a track follower coupled to the dose Setting
`member to follow rotation of this dose setting member and
`wherein the driver is disk shaped and the track has a Spiral
`shape which is engaged by the track follower which is
`flexibly coupled to the dose Setting member So that the track
`follower can be moved radially when it follows the track of
`the driver element.
`2. A limiting mechanism that prevents Setting of a dose
`that exceeds the amount of liquid left in a cartridge of an
`injection device wherein a dose is set by rotating a dose
`Setting member relative to a driver and away from a fixed
`Stop in the injection device, and the dose is injected by
`rotating back the dose Setting member which during this
`rotation carries the driver with it to rotate this driver which
`moves the piston rod forward, wherein the driver is provided
`with a track having a length which is related to the total
`
`6
`amount of medicament in the cartridge and which track is
`engaged by a track follower coupled to the dose Setting
`member to follow rotation of this dose setting member and
`wherein the driver is cylindrical and the track has a helical
`shape which is engaged by the track follower which is
`coupled to the dose Setting member So that the track follower
`can be moved rotationally when it follows the track of the
`driver element.
`3. The limiting mechanism of claim 2, wherein the dose
`Setting element is a cylinder concentric with the driver.
`4. The limiting mechanism of claim 3, wherein the track
`comprises a thread in the driver and that the track follower
`comprises a nut shaped member coupled to the dose Setting
`member and provided with a thread engaging the thread of
`the driver.
`
`1O
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`15
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`PFIZER, INC. v. SANOFI-AVENTIS DEUTSCHLAND GMBH
`
`Ex. 1017, p. 6 of 6
`
`