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WO1996039214A1 - A dosage unit for dosing measured amounts of a fluid - Google Patents

A dosage unit for dosing measured amounts of a fluid Download PDF

Info

Publication number
WO1996039214A1
WO1996039214A1 PCT/DK1995/000220 DK9500220W WO9639214A1 WO 1996039214 A1 WO1996039214 A1 WO 1996039214A1 DK 9500220 W DK9500220 W DK 9500220W WO 9639214 A1 WO9639214 A1 WO 9639214A1
Authority
WO
WIPO (PCT)
Prior art keywords
casing
piston rod
dosage unit
body part
liquid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/DK1995/000220
Other languages
French (fr)
Inventor
Niels Erik Holm
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ne Holm AS
Original Assignee
Ne Holm AS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to DK136593A priority Critical patent/DK170604B1/en
Application filed by Ne Holm AS filed Critical Ne Holm AS
Priority to PCT/DK1995/000220 priority patent/WO1996039214A1/en
Priority to AU26693/95A priority patent/AU2669395A/en
Publication of WO1996039214A1 publication Critical patent/WO1996039214A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/315—Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
    • A61M5/31565—Administration mechanisms, i.e. constructional features, modes of administering a dose
    • A61M5/31576—Constructional features or modes of drive mechanisms for piston rods
    • A61M5/31578—Constructional features or modes of drive mechanisms for piston rods based on axial translation, i.e. components directly operatively associated and axially moved with plunger rod
    • A61M5/3158—Constructional features or modes of drive mechanisms for piston rods based on axial translation, i.e. components directly operatively associated and axially moved with plunger rod performed by axially moving actuator operated by user, e.g. an injection button
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/315—Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
    • A61M5/31533—Dosing mechanisms, i.e. setting a dose
    • A61M5/31545—Setting modes for dosing
    • A61M5/31548—Mechanically operated dose setting member
    • A61M5/3155—Mechanically operated dose setting member by rotational movement of dose setting member, e.g. during setting or filling of a syringe
    • A61M5/31551—Mechanically operated dose setting member by rotational movement of dose setting member, e.g. during setting or filling of a syringe including axial movement of dose setting member
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/50—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests having means for preventing re-use, or for indicating if defective, used, tampered with or unsterile
    • A61M5/5013—Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/24—Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/178—Syringes
    • A61M5/31—Details
    • A61M5/315—Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
    • A61M5/31565—Administration mechanisms, i.e. constructional features, modes of administering a dose
    • A61M5/3159—Dose expelling manners
    • A61M5/31593—Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
    • A61M5/50—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests having means for preventing re-use, or for indicating if defective, used, tampered with or unsterile
    • A61M5/5013—Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe
    • A61M5/502—Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe for blocking the piston

Definitions

  • the invention relates to a dosage unit for dosing measured amounts of a liquid, where the dosage unit comprises a cylindrical casing of plastics for receiving the liquid in question, which is preferably placed in a separate container, said casing at the distal end comprising means for fastening a liquid outlet needle, and where said dosage unit comprises a piston rod for exerting a force on a piston so as to expel said liquid, whereby guide means are provided between the casing and the piston rod, said guide means being shaped integral with the casing and allowing a displacement of the piston rod in a direction towards the distal end of the casing and further preventing a displacement in the opposite direction, and where the piston rod comprises a body part with axially extending, substantially parallel side surfaces.
  • Such dosage units are known for instance from EP B1 327.910.
  • WO A1 92/12747 discloses a similar dosage unit.
  • This unit allows an infinitely variable setting and injection of measured amounts of insulin by means of a separate annular metal ring surrounding a piston rod with smooth walls, said ring having webs projecting radially inwards functioning as barbs relative to the piston rod.
  • This unit is both complicated to assemble and difficult to dispose of after use in case particular care is to be taken because the ring with the barbs is made of metal and the remain- ing parts of the unit are made of plastics.
  • the dosage unit according to the invention is characterised in that the casing comprises a passage member adapted to receive said body part and defined by a substantially planar side surface, which is adapted to abut one of the parallel side surfaces of said body part, as well as by at least two resilient projections, which are arranged in sequence when seen in the advancing direction of the piston rod and which in the relaxed state extend substantially perpendicular to the plane side surface of the passage mem ⁇ ber from an opposing side, the free end of each projection being spaced a distance therefrom which is shorter than the thickness of said body part, and whereby the free end of each projection is rounded in a curved man ⁇ ner.
  • the resulting dosage unit is relatively easy to manufacture and remove after use, and the piston rod can be displaced in an infinitely variable manner.
  • the piston rod allows a reliable expelling of measured amounts of any quantity without involving steps in the amounts. The latter is due to the fact that the forward movement of the piston rod towards the distal end is performed in an easy and infinitely variable manner by one side of the body part sliding in a reliably supported manner along the plane side surface of the passage member while the opposite side pushes the projections aside.
  • the piston rod is in a reliable and safe manner prevented from being retracted by the projections operating as wedges in any posi ⁇ tion, because when it is attempted to retract the piston rod said wedges instantaneously squeeze the said body part thereof in a firm and immov ⁇ able manner towards the plane side surface of the passage member.
  • the co-operating members in question can be manufactured without involving high requirements to the accuracy of the dimension tolerances, especially because the projections are rounded in a curved manner at their free ends. The latter implies that attempts at retracting the piston rod have the effect that the projections exert a force on the side of the piston rod with a progressively increasing radius due to the rolling movement against the curved surface. As a result, the projections lock the piston rod too by a progressively increasing force.
  • the dosage unit can be easily disposed of because it is made exclusively of plastics.
  • the presence of at least two projections contributes to support the piston rod in a sub ⁇ stantially rectilinear, axially extending moving path.
  • the projections may according to the invention be shaped integral with the casing, a hinge-forming thickness-reduction being pro ⁇ vided at the transition between each projection and the casing with the result that the necessary resilience is obtained in a very simple manner at the same time as the projections per se are ensured a suitable rigidity so as to be able to exert the desired wedge effect.
  • the dosage unit is according to the invention also characterised in that the projections are substantially plane parts with ridges along their free ends, whereby the surface area of the projections co-operating with the piston rod is relatively large.
  • one or more of the co-operating surfaces are preferably provided with a rough surface.
  • Fig. 1 is a longitudinal, cross-sectional view through a dosage unit
  • Fig. 2 an axial sectional view on a larger scale through the end of the casing of the dosage unit adjacent the piston, where said end is separated from the remaining portion of the unit without the piston rod,
  • Fig. 3 corresponds to Fig. 2, but where a portion of a piston rod is shown in engagement with the casing on the location in question, and
  • Fig. 4 is a sectional view of the casing with the piston rod, taken along the line l-l of Fig. 3, whereby parts are removed for the sake of clarity.
  • the dosage unit shown in Fig. 1 corresponds more or less to the unit known from EP-PS No. 0 327 910. It comprises a casing 1 for receiving a cartridge 2 of glass and containing a liquid 3, such as insulin.
  • the glass cartridge 2 comprises a piston 4 for pressing the liquid 3 out through a needle 5 inserted in the opposite end, said needle being secured to the casing 1 in a conventionally known manner by screwing on of a cup- shaped cap 6.
  • the glass cartridge 2 is retained in the casing by means of a retaining cap 7 which can be secured to the casing by a snapping effect.
  • the retaining cap 7 is adapted to be pierced by a projecting end of the needle 5, said end being capable of extending into the interior of the glass cartridge 2. This piercing and insertion of the needle 5 is preferably carried out during the screwing on of the needle-carrying cap 6 onto the retaining cap 7 of the casing 1 .
  • the dosage unit comprises a piston rod 8 for driving the piston 4 into the glass cartridge 2.
  • This piston rod 8 is of a cross section illustrated in Fig. 4 and comprises two oppositely arranged, longitudinal grooves 9, 10 with the result that the piston rod 8 comprises a centrally arranged longitudinal body part 1 1 which is defined by two parallel side surfaces 12, 13.
  • one side surface 13 is adapted to co-operate with a plane surface 14 provided on the casing 1
  • the other side surface 12 is adapted to to co-oper ⁇ ate with wedge-forming projections 15 and 16 provided on the casing.
  • This passage 17 is of a cross section corresponding to the piston rod 8 because it comprises a funnel-shaped part 18 opposite the body part at the inlet side of the cas- ing.
  • the plane side 14 and the oppositely arranged projections 15 and 16 are provided a short distance inside the opening of the passage 17 on their respective side of the part 19 of the passage 17, which is adapted to to receive the body part 1 1 of the piston 8.
  • the plane surface 14 is provided by means of an inwardly projecting web 20, which is supported by trans ⁇ verse walls 21 and 22 shaped integral with the outer wall 23 of the casing 1.
  • the projections 15 and 16 are shaped integral with the diametrically opposite side of the outer wall 23 of the casing 1 , said projections extend ⁇ ing substantially perpendicular towards the plane surface 14.
  • the projections 15 and 16 are of a substantially rectangular cross section with a raised inner edge 24 and 25, respectively.
  • the side of the projec ⁇ tions facing the plane surface 14 is curved, the free curved end surfaces of said projections forming parts of a cylindrical surface which extends parallel to the plane surface 14.
  • the projections 15 and 16 are dimen ⁇ sioned such that the distance between their free ends and the oppositely arranged plane surface 14 is shorter than the thickness of the body part 1 1 of the piston 8.
  • the piston rod 8 can be easily displaced in a forward direc ⁇ tion towards the needle-carrying distal end of the casing, i.e. downwardly relative to Fig. 3, while attempts at moving the piston in the opposite direction are prevented by the projections locking the piston rod in a wedge-like manner firmly against the plane surface 14. This locking can be carried out in any position of the piston 8 relative to the casing.
  • an opening 26 is provided in the wall of the casing. This opening is placed opposite the projections 15 and 16 and the portions forming the plane surface 14 in order to facilitate the casting of the casing made of a suitable, preferably transparent plastic material.
  • the projections 15 and 16 are resilient in such a manner that the piston rod 8 can be easily moved forwards relative to the casing 1. This resilience is suitably obtained by allowing the projections 15 and 16 to be connected to the outer wall of the casing 1 through thickness-reduc- tions 27 and 28 immediately adjacent the outer wall 23 of the casing 1.
  • the piston rod 8 comprises portions of a thread 30 shaped along its external periphery and on which a nut means 31 is screwed.
  • the nut means 31 comprises radially protruding projections 32 and 33 which extend axially along the outer side of the nut means 31 and which are received in mating grooves 38 and 39, respectively, in a surrounding, sleeve-shaped adjustment means 40.
  • the adjustment means 40 comprises an inner circumferential groove at the end adjacent the casing 1 , said groove receiving a circumferential projection on the casing in such manner that it is possible to turn the adjustment means 40 simultaneously with said adjustment means being retained so as not to be axially displaced relative to the casing.
  • the nut means 31 is shaped integral with a tubular indicator 41 extending coaxially with the piston rod 8 in a direction away from the casing 1 between the piston rod 8 and the adjustment means 1 8.
  • the indicator 41 At its free end projecting beyond the adjustment means 40, the indicator 41 comprises an end button 42 shaped with substantially the same external diameter as the adjustment means 18.
  • the dosage unit comprises furthermore a removable cap 43 for protection of the needle 5 when the dosage unit is not used.
  • the dosage unit operates in the following manner.
  • the adjustment means 40 is turned relative to the casing 1 and the cap 43 fixed thereon.
  • the nut means 31 follows the turning while the possibility of said nut means 31 abutting the end of the casing 1 prevent a turning of the adjustment means in the incorrect direction.
  • the rotation of the nut means 31 relative to the piston rod 8 implies that it is forced in a direction away from the glass cartridge 2 due to the thread 30, whereby the indicator 41 is moved axially away from the free end of the adjustment means 40.
  • a measuring scale appears on the outer side of the indicator 41 .
  • This scale can be divided up so as to allow a reading of the dosing quan ⁇ tity in question for every full turn of the adjustment means relative to the cap 43 while a scale not shown on the end of the adjustment means adjacent the cap 43 indicates the dosing quantity by portions of a full turn of the adjustment means 40 relative to the cap 43.
  • the displacement of the indicator 41 and the nut means 31 connected thereto causes a displacement of the piston rod 8 a corresponding distance, whereby the piston 4 of the glass cartridge 2 is pressed towards the outlet end of the liquid 3. In this manner an amount of liquid is pressed out of the glass cartridge, said amount corresponding to the measured amount on the measuring scales.
  • the dosage unit is of the same length as before the setting.
  • the piston rod 8 is retained against retraction by means of the projections 15 and 16 and the opposing plane surface 14 in the casing 1.
  • the piston rod 8 is moved slightly forward by a pushing aside of the projections 15 and 16.
  • the piston rod can be stopped in any position with the result that any desired dosage of the liquid 3 can be expelled without involving a stepwise variation thereof.
  • the body part of the piston rod 8 is of a thickness of 1.8 mm while the distance between the ends of the projections 15, 16 and the plane surface 14 in the relaxed state is 1.65 mm.
  • the curved end surfaces of the projections 15, 16 are suitably of a radius of curvature of 3 mm.
  • the piston rod may for instance be of another cross-section than the one shown, such as shaped with a body part in form of a projecting rib.
  • one or more of the engaging surfaces may be shaped with a rough surface, which, however, must not be of such a shape that only a stepwise movement of the piston rod is possible.
  • the number of projections and the shape thereof may vary.

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  • Health & Medical Sciences (AREA)
  • Vascular Medicine (AREA)
  • Engineering & Computer Science (AREA)
  • Anesthesiology (AREA)
  • Biomedical Technology (AREA)
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  • Veterinary Medicine (AREA)
  • Infusion, Injection, And Reservoir Apparatuses (AREA)
  • Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)

Abstract

A dosage unit for dosing measured amounts of a liquid (3) comprises a cylindrical casing (1) for receiving a container (2) with the liquid (3) in question. At the distal end the casing (1) comprises a liquid outlet needle (5). The dosage unit comprises furthermore a piston rod (8) for exerting a force on a piston (4) so as to expel the liquid. The piston rod (8) comprises a body part (11) with axially extending, substantially parallel side surfaces (12, 13), while the casing comprises a passage member (19) adapted to receive said body part (11) and defined by a substantially planar side surface (14), which is adapted to abut one (13) of the parallel side surfaces (12, 13) of said body part. The passage member (19) is also defined by a plurality of resilient projections (15, 16), which in the relaxed state extend substantially perpendicular to the plane side surface (14) of the passage member (19) from an opposing side, the free end of each projection being spaced a distance therefrom which is shorter than the thickness of said body part (11). As a result, the piston rod (8) can only be displaced in a forward direction towards the distal end of the casing.

Description

Title: A dosage unit for dosing measured amounts of a fluid-
Technical Field
The invention relates to a dosage unit for dosing measured amounts of a liquid, where the dosage unit comprises a cylindrical casing of plastics for receiving the liquid in question, which is preferably placed in a separate container, said casing at the distal end comprising means for fastening a liquid outlet needle, and where said dosage unit comprises a piston rod for exerting a force on a piston so as to expel said liquid, whereby guide means are provided between the casing and the piston rod, said guide means being shaped integral with the casing and allowing a displacement of the piston rod in a direction towards the distal end of the casing and further preventing a displacement in the opposite direction, and where the piston rod comprises a body part with axially extending, substantially parallel side surfaces.
Background Art
Various types of dosage units of the above type are known, where the piston rod is associated with adjustment means allowing the user in advance to set the dosage unit to deliver a specific amount of liquid by way of a succeeding activation of the piston rod. The piston rod is dis¬ placed during the activation in a forward direction towards the distal end of the casing, a displacement in the opposite direction being prevented by a ratchet device being provided between the casing and the piston. It turned out that such a ratchet device is difficult to manufacture because the engaging parts must be manufactured with very small dimension toler¬ ances. In addition, the use of a ratchet device involves a lower limit for the accuracy by which the measured amounts of liquid can be set and de¬ livered. When the existing dosage units for dosing measured amounts of insulin are used, the ratchet device has the effect that the measured amounts differ by steps of two units.
Such dosage units are known for instance from EP B1 327.910.
WO A1 92/12747 discloses a similar dosage unit.This unit allows an infinitely variable setting and injection of measured amounts of insulin by means of a separate annular metal ring surrounding a piston rod with smooth walls, said ring having webs projecting radially inwards functioning as barbs relative to the piston rod. This unit is both complicated to assemble and difficult to dispose of after use in case particular care is to be taken because the ring with the barbs is made of metal and the remain- ing parts of the unit are made of plastics.
Brief Description of the Invention.
The dosage unit according to the invention is characterised in that the casing comprises a passage member adapted to receive said body part and defined by a substantially planar side surface, which is adapted to abut one of the parallel side surfaces of said body part, as well as by at least two resilient projections, which are arranged in sequence when seen in the advancing direction of the piston rod and which in the relaxed state extend substantially perpendicular to the plane side surface of the passage mem¬ ber from an opposing side, the free end of each projection being spaced a distance therefrom which is shorter than the thickness of said body part, and whereby the free end of each projection is rounded in a curved man¬ ner.
The resulting dosage unit is relatively easy to manufacture and remove after use, and the piston rod can be displaced in an infinitely variable manner. In addition, the piston rod allows a reliable expelling of measured amounts of any quantity without involving steps in the amounts. The latter is due to the fact that the forward movement of the piston rod towards the distal end is performed in an easy and infinitely variable manner by one side of the body part sliding in a reliably supported manner along the plane side surface of the passage member while the opposite side pushes the projections aside. The piston rod is in a reliable and safe manner prevented from being retracted by the projections operating as wedges in any posi¬ tion, because when it is attempted to retract the piston rod said wedges instantaneously squeeze the said body part thereof in a firm and immov¬ able manner towards the plane side surface of the passage member. The co-operating members in question can be manufactured without involving high requirements to the accuracy of the dimension tolerances, especially because the projections are rounded in a curved manner at their free ends. The latter implies that attempts at retracting the piston rod have the effect that the projections exert a force on the side of the piston rod with a progressively increasing radius due to the rolling movement against the curved surface. As a result, the projections lock the piston rod too by a progressively increasing force. As the piston rod is always slidingly engag¬ ing the plane surface and the projections, respectively, the movement of the piston rod is completely noiseless. After use, the dosage unit can be easily disposed of because it is made exclusively of plastics. The presence of at least two projections contributes to support the piston rod in a sub¬ stantially rectilinear, axially extending moving path.
In addition, the projections may according to the invention be shaped integral with the casing, a hinge-forming thickness-reduction being pro¬ vided at the transition between each projection and the casing with the result that the necessary resilience is obtained in a very simple manner at the same time as the projections per se are ensured a suitable rigidity so as to be able to exert the desired wedge effect.
The dosage unit is according to the invention also characterised in that the projections are substantially plane parts with ridges along their free ends, whereby the surface area of the projections co-operating with the piston rod is relatively large.
Finally according to the invention one or more of the co-operating surfaces are preferably provided with a rough surface.
Brief Description of the Drawings.
The invention is explained in greater detail below with reference to the accompanying drawing, in which
Fig. 1 is a longitudinal, cross-sectional view through a dosage unit,
Fig. 2 an axial sectional view on a larger scale through the end of the casing of the dosage unit adjacent the piston, where said end is separated from the remaining portion of the unit without the piston rod,
Fig. 3 corresponds to Fig. 2, but where a portion of a piston rod is shown in engagement with the casing on the location in question, and
Fig. 4 is a sectional view of the casing with the piston rod, taken along the line l-l of Fig. 3, whereby parts are removed for the sake of clarity.
Best Mode for Carrying Out the Invention
The dosage unit shown in Fig. 1 corresponds more or less to the unit known from EP-PS No. 0 327 910. It comprises a casing 1 for receiving a cartridge 2 of glass and containing a liquid 3, such as insulin. The glass cartridge 2 comprises a piston 4 for pressing the liquid 3 out through a needle 5 inserted in the opposite end, said needle being secured to the casing 1 in a conventionally known manner by screwing on of a cup- shaped cap 6. The glass cartridge 2 is retained in the casing by means of a retaining cap 7 which can be secured to the casing by a snapping effect. The retaining cap 7 is adapted to be pierced by a projecting end of the needle 5, said end being capable of extending into the interior of the glass cartridge 2. This piercing and insertion of the needle 5 is preferably carried out during the screwing on of the needle-carrying cap 6 onto the retaining cap 7 of the casing 1 .
At the end opposite the needle 5 the dosage unit comprises a piston rod 8 for driving the piston 4 into the glass cartridge 2. This piston rod 8 is of a cross section illustrated in Fig. 4 and comprises two oppositely arranged, longitudinal grooves 9, 10 with the result that the piston rod 8 comprises a centrally arranged longitudinal body part 1 1 which is defined by two parallel side surfaces 12, 13. As clearly illustrated in Figs. 2 and 3, one side surface 13 is adapted to co-operate with a plane surface 14 provided on the casing 1 , while the other side surface 12 is adapted to to co-oper¬ ate with wedge-forming projections 15 and 16 provided on the casing. The plane surface 14 and the projections 15 and 16 of the casing oppose one another on their respective side of a passage 17 shaped at the end of the casing 1 which is farthest away from the needle. This passage 17 is of a cross section corresponding to the piston rod 8 because it comprises a funnel-shaped part 18 opposite the body part at the inlet side of the cas- ing.
The plane side 14 and the oppositely arranged projections 15 and 16 are provided a short distance inside the opening of the passage 17 on their respective side of the part 19 of the passage 17, which is adapted to to receive the body part 1 1 of the piston 8. The plane surface 14 is provided by means of an inwardly projecting web 20, which is supported by trans¬ verse walls 21 and 22 shaped integral with the outer wall 23 of the casing 1. The projections 15 and 16 are shaped integral with the diametrically opposite side of the outer wall 23 of the casing 1 , said projections extend¬ ing substantially perpendicular towards the plane surface 14. The projections 15 and 16 are of a substantially rectangular cross section with a raised inner edge 24 and 25, respectively. The side of the projec¬ tions facing the plane surface 14 is curved, the free curved end surfaces of said projections forming parts of a cylindrical surface which extends parallel to the plane surface 14. The projections 15 and 16 are dimen¬ sioned such that the distance between their free ends and the oppositely arranged plane surface 14 is shorter than the thickness of the body part 1 1 of the piston 8. When the piston 8 is correctly positioned in the casing 1 , it has therefore pushed the projections 15 and 16 slightly inwards towards the interior of the casing, cf. Fig. 3.
In this manner the piston rod 8 can be easily displaced in a forward direc¬ tion towards the needle-carrying distal end of the casing, i.e. downwardly relative to Fig. 3, while attempts at moving the piston in the opposite direction are prevented by the projections locking the piston rod in a wedge-like manner firmly against the plane surface 14. This locking can be carried out in any position of the piston 8 relative to the casing.
As illustrated in Figs. 2 and 3, an opening 26 is provided in the wall of the casing. This opening is placed opposite the projections 15 and 16 and the portions forming the plane surface 14 in order to facilitate the casting of the casing made of a suitable, preferably transparent plastic material.
As illustrated, the projections 15 and 16 are resilient in such a manner that the piston rod 8 can be easily moved forwards relative to the casing 1. This resilience is suitably obtained by allowing the projections 15 and 16 to be connected to the outer wall of the casing 1 through thickness-reduc- tions 27 and 28 immediately adjacent the outer wall 23 of the casing 1.
As illustrated in Figs. 1 and 4, the piston rod 8 comprises portions of a thread 30 shaped along its external periphery and on which a nut means 31 is screwed. On the outer side, the nut means 31 comprises radially protruding projections 32 and 33 which extend axially along the outer side of the nut means 31 and which are received in mating grooves 38 and 39, respectively, in a surrounding, sleeve-shaped adjustment means 40. The adjustment means 40 comprises an inner circumferential groove at the end adjacent the casing 1 , said groove receiving a circumferential projection on the casing in such manner that it is possible to turn the adjustment means 40 simultaneously with said adjustment means being retained so as not to be axially displaced relative to the casing. The nut means 31 is shaped integral with a tubular indicator 41 extending coaxially with the piston rod 8 in a direction away from the casing 1 between the piston rod 8 and the adjustment means 1 8. At its free end projecting beyond the adjustment means 40, the indicator 41 comprises an end button 42 shaped with substantially the same external diameter as the adjustment means 18.
The dosage unit comprises furthermore a removable cap 43 for protection of the needle 5 when the dosage unit is not used.
The dosage unit operates in the following manner. The adjustment means 40 is turned relative to the casing 1 and the cap 43 fixed thereon. As a result, the nut means 31 follows the turning while the possibility of said nut means 31 abutting the end of the casing 1 prevent a turning of the adjustment means in the incorrect direction. The rotation of the nut means 31 relative to the piston rod 8 implies that it is forced in a direction away from the glass cartridge 2 due to the thread 30, whereby the indicator 41 is moved axially away from the free end of the adjustment means 40. As a result a measuring scale appears on the outer side of the indicator 41 . This scale can be divided up so as to allow a reading of the dosing quan¬ tity in question for every full turn of the adjustment means relative to the cap 43 while a scale not shown on the end of the adjustment means adjacent the cap 43 indicates the dosing quantity by portions of a full turn of the adjustment means 40 relative to the cap 43. When the desired dosing quantity has been set, the turning of the adjust¬ ment means 40 is stopped. Then the cap 43 is removed and the dosage unit is placed on the desired location by the needle 5 being inserted. Subsequently, the indicator 41 is forced back into the adjustment means 40 by pressing on the end button 42 until said movement is stopped by the abutment of the nut means 31 against the end of the casing 1 . The displacement of the indicator 41 and the nut means 31 connected thereto causes a displacement of the piston rod 8 a corresponding distance, whereby the piston 4 of the glass cartridge 2 is pressed towards the outlet end of the liquid 3. In this manner an amount of liquid is pressed out of the glass cartridge, said amount corresponding to the measured amount on the measuring scales. When the injection of liquid has been completed, the dosage unit is of the same length as before the setting.
During the setting, the piston rod 8 is retained against retraction by means of the projections 15 and 16 and the opposing plane surface 14 in the casing 1. During the pressing of the end button 42 and consequently during the pressing out of the liquid 3 from the needle 5, the piston rod 8 is moved slightly forward by a pushing aside of the projections 15 and 16. As the projections 15 and 16 and the plane surface 14 as well as the body part 1 1 of the piston rod engage one another along surfaces, the piston rod can be stopped in any position with the result that any desired dosage of the liquid 3 can be expelled without involving a stepwise variation thereof.
According to an advantageous embodiment of the invention, the body part of the piston rod 8 is of a thickness of 1.8 mm while the distance between the ends of the projections 15, 16 and the plane surface 14 in the relaxed state is 1.65 mm. The curved end surfaces of the projections 15, 16 are suitably of a radius of curvature of 3 mm.
The invention has been described with reference to a preferred embodi- ment of the invention. Many modifications can be carried out without thereby deviating from the scope of the invention. The piston rod may for instance be of another cross-section than the one shown, such as shaped with a body part in form of a projecting rib. In addition, one or more of the engaging surfaces may be shaped with a rough surface, which, however, must not be of such a shape that only a stepwise movement of the piston rod is possible. Furthermore, the number of projections and the shape thereof may vary.

Claims

Claims.
1. A dosage unit for dosing measured amounts of a liquid, where the dosage unit comprises a cylindrical casing (1) of plastics for receiving the liquid (3) in question, which is preferably placed in a separate container (2), said casing (1) at the distal end comprising means for fastening a liquid outlet needle (5), and where said dosage unit comprises a piston rod (8) for exerting a force on a piston (4) so as to expel said liquid (3), where¬ by guide means are provided between the casing (1) and the piston rod (8), said guide means being shaped integral with the casing (1) and allow- ing a displacement of the piston rod (8) in a direction towards the distal end of the casing (1 ) and further preventing a displacement in the opposite direction, and where the piston rod (8) comprises a body part (11) with axially extending, substantially parallel side surfaces (12, 13), charac¬ ter! s e d in that the casing comprises a passage member (19) adapted to receive said body part (11) and defined by a substantially planar side surface (14), which is adapted to abut one of the parallel side surfaces (12, 13) of said body part (11), as well as by at least two resilient pro¬ jections (15, 16), which are arranged in sequence when seen in the advan¬ cing direction of the piston rod (8) and which in the relaxed state extend substantially perpendicular to the plane side surface (14) of the passage member (19) from an opposing side, the free end of each projection (15, 16) being spaced a distance therefrom which is shorter than the thickness of said body part (11), and whereby the free end of each projection (15, 16) is rounded in a curved manner.
2. A dosage unit as claimed in claim 1, characterised in that a hinge-forming thickness-reduction (27, 28) is provided at the transition between each projection and the casing.
3. A dosage unit as claimed in claim 1 or 2, c hara cte r ised in that the projections (15, 16) are substantially plane parts with ridges (24, 25) along their free ends.
4. A dosage unit as claimed in one or more of the claims 1 to 3, char¬ acte ri sed in that one or more of the co-operating surfaces (12, 15; 12, 16; 13, 14) are shaped with a rough surface.
PCT/DK1995/000220 1993-12-07 1995-06-06 A dosage unit for dosing measured amounts of a fluid Ceased WO1996039214A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
DK136593A DK170604B1 (en) 1993-12-07 1993-12-07 Metering unit for metering measured-off quantities of a liquid
PCT/DK1995/000220 WO1996039214A1 (en) 1993-12-07 1995-06-06 A dosage unit for dosing measured amounts of a fluid
AU26693/95A AU2669395A (en) 1995-06-06 1995-06-06 A dosage unit for dosing measured amounts of a fluid

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DK136593A DK170604B1 (en) 1993-12-07 1993-12-07 Metering unit for metering measured-off quantities of a liquid
PCT/DK1995/000220 WO1996039214A1 (en) 1993-12-07 1995-06-06 A dosage unit for dosing measured amounts of a fluid

Publications (1)

Publication Number Publication Date
WO1996039214A1 true WO1996039214A1 (en) 1996-12-12

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US6716198B2 (en) 2000-05-18 2004-04-06 Novo Nordisk A/S Injection device
WO2007017281A1 (en) * 2005-08-11 2007-02-15 Arzneimittel Gmbh Apotheker Vetter & Co. Ravensburg Syringe
EP2201972A1 (en) * 2008-12-23 2010-06-30 Sanofi-Aventis Deutschland GmbH Fixed dose injection device with resettable drive mechanism
WO2010139641A1 (en) * 2009-06-01 2010-12-09 Sanofi-Aventis Deutschland Gmbh Spindle and bearing combination and drug delivery device
US8257319B2 (en) 2009-06-01 2012-09-04 Sanofi-Aventis Deutschland Gmbh Drug delivery device inner housing having helical spline
US8585656B2 (en) 2009-06-01 2013-11-19 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for priming a drug delivery device
US8672896B2 (en) 2009-06-01 2014-03-18 Sanofi-Aventis Deutschland Gmbh Inner housing for a drug delivery device
US8728043B2 (en) 2009-06-01 2014-05-20 Sanofi-Aventis Deutschland Gmbh Drive mechanism for a drug delivery device
US8790315B2 (en) 2009-06-01 2014-07-29 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for a drug delivery device
US8974423B2 (en) 2009-06-01 2015-03-10 Sanofi-Aventis Deutschland Gmbh Resettable drug delivery device
CN104436375A (en) * 2014-12-30 2015-03-25 江苏华阳电器有限公司 Injection pen
US9005171B2 (en) 2009-06-01 2015-04-14 Sanofi-Aventis Deutschland Gmbh Resettable drug delivery device
US9125994B2 (en) 2009-06-01 2015-09-08 Sanofi—Aventis Deutschland GmbH Drug delivery device with dose dial sleeve rotational stop
US9238106B2 (en) 2009-06-01 2016-01-19 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for priming a drug delivery device
US9345840B2 (en) 2009-06-01 2016-05-24 Sanofi-Aventis Deutschland Gmbh Drug delivery dose setting mechanism with variable maximum dose
US9352097B2 (en) 2009-06-01 2016-05-31 Sanofi-Aventis Deutschland Gmbh Spindle for a drug delivery device
US9457150B2 (en) 2009-06-01 2016-10-04 Sanofi-Aventis Deutschland Gmbh Biasing mechanism for a drug delivery device
US9463283B2 (en) 2009-06-01 2016-10-11 Sanofi-Aventis Deutschland Gmbh Dosing mechanism for a drug deliver device
US9950116B2 (en) 2009-06-01 2018-04-24 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for priming a drug delivery device

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US6716198B2 (en) 2000-05-18 2004-04-06 Novo Nordisk A/S Injection device
WO2007017281A1 (en) * 2005-08-11 2007-02-15 Arzneimittel Gmbh Apotheker Vetter & Co. Ravensburg Syringe
US8137324B2 (en) 2005-08-11 2012-03-20 Arzneimittel Gmbh Apotheker Vetter & Co. Ravensburg Syringe with internal safety device
US8945069B2 (en) 2008-12-23 2015-02-03 Sanofi-Aventis Deutschland Gmbh Injection device
EP2201972A1 (en) * 2008-12-23 2010-06-30 Sanofi-Aventis Deutschland GmbH Fixed dose injection device with resettable drive mechanism
WO2010072662A1 (en) * 2008-12-23 2010-07-01 Sanofi-Aventis Deutschland Gmbh Fixed dose injection device with resettable drive mechanism
US9089656B2 (en) 2009-06-01 2015-07-28 Sanofi-Aventis Deutschland Gmbh Spindle and bearing combination and drug delivery device
US9125993B2 (en) 2009-06-01 2015-09-08 Sanofi-Aventis Deutschland Gmbh Inner housing for a drug delivery device
US8317757B2 (en) 2009-06-01 2012-11-27 Sanofi-Aventis Deutschland Gmbh Drug delivery device inner housing having helical spline
US8585656B2 (en) 2009-06-01 2013-11-19 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for priming a drug delivery device
US8672896B2 (en) 2009-06-01 2014-03-18 Sanofi-Aventis Deutschland Gmbh Inner housing for a drug delivery device
US8728043B2 (en) 2009-06-01 2014-05-20 Sanofi-Aventis Deutschland Gmbh Drive mechanism for a drug delivery device
US8790315B2 (en) 2009-06-01 2014-07-29 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for a drug delivery device
CN102458527B (en) * 2009-06-01 2014-12-10 赛诺菲-安万特德国有限公司 Mandrel and support assembly and drug delivery device
CN102458527A (en) * 2009-06-01 2012-05-16 赛诺菲-安万特德国有限公司 Spindle and support combination and drug delivery device
US8974423B2 (en) 2009-06-01 2015-03-10 Sanofi-Aventis Deutschland Gmbh Resettable drug delivery device
US11654243B2 (en) 2009-06-01 2023-05-23 Sanofi-Aventis Deutschland Gmbh Inner housing for a drug delivery device
US9005171B2 (en) 2009-06-01 2015-04-14 Sanofi-Aventis Deutschland Gmbh Resettable drug delivery device
WO2010139641A1 (en) * 2009-06-01 2010-12-09 Sanofi-Aventis Deutschland Gmbh Spindle and bearing combination and drug delivery device
US9108007B2 (en) 2009-06-01 2015-08-18 Sanofi-Aventis Deutschland Gmbh Spindle and bearing combination and drug delivery device
US9125994B2 (en) 2009-06-01 2015-09-08 Sanofi—Aventis Deutschland GmbH Drug delivery device with dose dial sleeve rotational stop
US8257319B2 (en) 2009-06-01 2012-09-04 Sanofi-Aventis Deutschland Gmbh Drug delivery device inner housing having helical spline
US9199040B2 (en) 2009-06-01 2015-12-01 Sanofi-Aventis Deutschland Gmbh Drug delivery device last dose lock-out mechanism
US9238106B2 (en) 2009-06-01 2016-01-19 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for priming a drug delivery device
US9345840B2 (en) 2009-06-01 2016-05-24 Sanofi-Aventis Deutschland Gmbh Drug delivery dose setting mechanism with variable maximum dose
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US9408978B2 (en) 2009-06-01 2016-08-09 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for priming a drug delivery device
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US9463283B2 (en) 2009-06-01 2016-10-11 Sanofi-Aventis Deutschland Gmbh Dosing mechanism for a drug deliver device
US9623187B2 (en) 2009-06-01 2017-04-18 Sanofi-Aventis Deutschland Gmbh Resettable drug delivery device
US9950116B2 (en) 2009-06-01 2018-04-24 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for priming a drug delivery device
US10034982B2 (en) 2009-06-01 2018-07-31 Sanofi-Aventis Deutschland Gmbh Spindle for a drug delivery device
US10195354B2 (en) 2009-06-01 2019-02-05 Sanofi-Aventis Deutschland Gmbh Resettable drug delivery device
US10279116B2 (en) 2009-06-01 2019-05-07 Sanofi-Aventis Deutschland Gmbh Dose setting mechanism for priming a drug delivery device
US10391254B2 (en) 2009-06-01 2019-08-27 Sanofi-Aventis Deutschland Gmbh Inner housing for a drug delivery device
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Also Published As

Publication number Publication date
DK170604B1 (en) 1995-11-13
DK136593A (en) 1995-06-08
DK136593D0 (en) 1993-12-07

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