Measured dose dispensing device

• US 4,865,591 A
• Filed: 06/10/1988
• Issued: 09/12/1989
• Est. Priority Date: 06/12/1987
• Status: Expired due to Fees

• Current Assignee: Hypoguard UK Ltd (ARKRAY, Inc)
• Original Assignee: Hypoguard UK Ltd (ARKRAY, Inc)
• Inventors: Sams, Bernard
• Primary Examiner(s): Schwadron, Martin P.
• Assistant Examiner(s): Flanigan, Allen J.
• Application Number:
  US07/205,198
• Time in Patent Office: 459 Days
• Field of Search: 604/186, 604/208, 604/209, 604/210, 604/211, 222/43, 222/309, 222/325, 222/326, 222/327, 222/391, 222/287
• US Class Current: 604/186
• CPC Class Codes: A61M 5/31541 Means preventing setting of a dose beyond the amount remaining in the cartridge
• CPC Class Codes: A61M 5/31543 piston rod reset means, i.e. means for causing or facilitating retraction of piston rod to its starting position during cartridge change
• CPC Class Codes: A61M 5/31553 without axial movement of dose setting member
• CPC Class Codes: A61M 5/31556 Accuracy improving means
• CPC Class Codes: A61M 5/3157 Means providing feedback signals when administration is completed A61M5/20 takes precedence
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• CPC Class Codes: A61M 5/502 for blocking the piston
• CPC Class Codes: G01F 11/023 with provision for varying the stroke of the piston

Abstract

The present invention relates to a device for dispensing a fluid from a container by means of the axial movement of a piston within the container under the influence of a plunger moved by the device, which device is adapted to receive the container on its forward end and to move the plunger axially forward towards or within the container so as to dispense a selected amount of fluid from the container upon each actuation of the device, characterized in that the device comprises:

i. a disengageable drive mechanism adapted to be reciprocated axially of the device and adapted to positively engage the plunger whereby the plunger can be moved axially forward by the drive mechanism and to be disengaged from the plunger to permit relative axial movement between the drive mechanism and the plunger;

ii. a disengagement means for selectively engaging or disengaging the drive means from the plunger;

iii. an actuating means, which may be integral with or separate from the disengagement means, for actuating the disengagement means, which actuation means requires a positive operation from a user of the device to engage and/or disengage the drive mechanism from the plunger; and

iv. means for selecting the extent of travel of the drive mechanism so as to control the extent of axial movement of the plunger upon actuation of the device.

The invention also provides a device of the invention in association with a container of the fluid to be dispensed.

Claims

1. A device for dispensing a controlled amount of fluid from a container, which device comprises an assembly adapted to be mounted upon a container in which a plunger is adapted to be moved axially along the container in increments so as to drive a piston within the container and thus to dispense fluid from the container characterised in that the assembly comprises a drive mechanism adapted to be reciprocated axially of the device and to be positively engaged with the plunger for the forward stroke of the drive mechanism so as to prevent relative movement between the plunger and the drive mechanism and to move the plunger forward in the container, which drive mechanism requires a positive action to disengage it from the plunger so as to permit relative movement of the plunger and drive mechanism for at least rearward movement of the drive mechanism;

in that the forward travel of the drive mechanism is limited by a fixed stop mechanism; and

in that the extent of the forward stroke of the drive mechanism is selected by withdrawing the drive mechanism a selected distance from the said fixed stop.

2. A device as claimed in claim 1 which comprises:

a. a hollow body member having one end adapted to receive and retain the fluid container

b. a plunger carried by said body member and adapted to be moved axially in a series of increments and to bear against the piston within the container so as to move the said piston to dispense doses of fluid from the container at each incremental movement of the plunger

c. a push member carried by said body member for axial movement with respect to said body member and having means for achieving positive engagement with the said plunger in the forward direction of travel of the push member

d. means requiring positive operation for releasing said positive engagement and thus permitting relative axial movement between the push member and the plunger in at least the rearward direction of travel of the said push member

e. a stop means against which the push member or a part associated therewith butts at the extreme of the plunger'"'"'s forward travel on each of its incremental movements

f. means for withdrawing the push member or its said associated part axially from the stop means to a selected distance whereby the extent of each incremental forward movement of the plunger can be selected

g. means for inhibiting rearward movement of the plunger whilst the container is located upon the body member

3. A device as claimed in claim 2 wherein there is provided a second stop means carried by said plunger which is engaged by the drive mechanism as it is retracted whereby the second stop member prevents the drive mechanism from being withdrawn to its full extent if the residual potential travel of the plunger is less than the desired dose.

4. A device as claimed in claim 1 wherein means are provided whereby the inhibition of the rearward movement of the plunger is removed or released when the container is removed from the body member.

5. A device as claimed in claim 4 wherein rearward movement of the plunger is prevented by a ratchet mechanism which is engaged by rotating part of the body member which also locks the container in position.

6. A device as claimed in claim 1 wherein the positive drive between the plunger and the drive mechanism is achieved by means of a radially acting mechanism which engages the shank of the axially reciprocable plunger member.

7. A device as claimed in claim 6 wherein the plunger has a series of ratchet teeth along its outer surface which are engaged directly or indirectly by a radially expansible toothed clamp member carried terminally by a sleeve push member journalled for axial movement within the device.

8. A device as claimed in claim 7 wherein the sleeve member is moveable axially by rotation thereof using a screw thread mechanism.

9. A device as claimed in claim 6 wherein the radially acting mechanism is actuated by rotation of a cam or similar mechanism to drive the radially acting mechanism radially inwardly into engagement with the plunger.

10. A device for administering insulin from a cylindrical cartridge having a piston journalled therein for axial movement along the cartridge to dispense the insulin contents of the cartridge through a needle outlet into the body of a user, which device comprises:

a. a cylindrical hollow body member having one end adapted to receive and retain the cartridge

b. a plunger journalled within the said body member and adapted to be moved axially in a series of increments and to bear against the piston within the container so as to move the said piston to dispense discrete and selectable doses of insulin from the cartridge at each incremental movement of the plunger

c. a generally cylindrical push sleeve journalled within the said body member for axial movement with respect to said body member

d. a pair of opposed clamp members mounted for radial movement within the said body member and which can be moved radially inwardly to positively engage the said plunger in the forward direction of travel of the push sleeve whereby the plunger is driven forward by the said sleeve, but which can be moved radially outwardly to disengage from the said plunger for the rearward movement of the said sleeve to permit relative axial movement between the push sleeve and the plunger in at least the rearward direction of travel of the said push sleeve

d. cam means operable from the exterior of the said body member and requiring positive operation for moving the said clamp members radially inward or outward

e. an inwardly directed shoulder within the body member which acts as a stop means against which the push member or the clamp members but at the extreme of the plunger'"'"'s forward travel on each of its incremental movements

f. an external rotatable member co-axial with the said body member for rotating the said sleeve member and causing it to move axially under the influence of a screw thread mechanism co-operating between the said body and the said sleeve whereby the sleeve can be moved rearwardly to a selected extent from the said stop shoulder when the clamp members are disengaged from the said plunger and thereby select tee extent of forward travel of the plunger when the clamp members are re-engaged with the plunger for forward movement thereof.

11. A hand portable device for dispensing a fluid from a container by means of the axial movement of a piston within the container under the influence of a plunger moved by the device, which device is adapted to receive the container at its forward end and to move the plunger axially forward toward the container so as to dispense a selected amount of fluid from the container upon each actuation of the device, characterised in that the device comprises a drive mechanism adapted to be reciprocated axially of the device and to be positively engaged with the plunger for the forward stroke of the drive mechanism so as to prevent relative movement between the plunger and the drive mechanism and to move the plunger forward, which drive mechanism requires a positive action to disengage it from the plunger so as to permit relative movement between the plunger and drive mechanism for at least rearward movement of the drive mechanism;

in that the forward travel of the drive mechanism is limited by a fixed stop mechanism; and

in that the extent of the forward stroke of the drive mechanism is individually selectable for each actuation of the device by withdrawing the drive mechanism or a part operatively associated, therewith a selected distance from a fixed stop defined by said fixed stop mechanism.

14. A device as claimed in claim 11 wherein the plunger carries an axial series of transverse teeth and the drive mechanism carries corresponding teeth adapted to engage the teeth on the plunger when in the drive engaged position.

15. A device as claimed in claim 11 wherein the drive mechanism is actuated by a radially acting cam means which acts to move the mechanism radially inward to engage the plunger and to retain it in engagement with said plunger during forward movement of the plunger.

16. A device as claimed in claim 11 wherein the device is provided with means for positively acting on said plunger so as to prevent rearwards movement of said plunger at all times when a container is mounted on the device.

17. A device as claimed in claim 11 wherein said datum point is provided by a stop means against which a component selected from the drive mechanism and a part operatively associated therewith buts at the extreme of the forward travel of plunger on each of its incremental movements.

18. A device as claimed in claim 11 wherein there is provided a second stop means carried by said plunger which is engaged by a component selected from the drive mechanism and a part operatively asociated therewith as it is retracted, whereby the second stop member prevents the drive mechanism from being withdrawn to its full extent if the residual potential travel of the plunger is less than the desired dose.

19. A device as claimed in claim 11 having a container containing a medicament is mounted at its forward end.

12. A hand portable device for dispensing a fluid from a container by means of the axial movement of a piston within the container under the influence of a plunger moved by the device, which device is adapted to receive the container at its forward end and to move the plunger to dispense a selected amount of fluid from the container upon each actuation of the device, characterised in that the device by axially moving said drive mechanism a selected amount relative to said plunger while said drive mechanism is disengaged therefrom comprises:

i. a disengageable drive mechanism adapted to be reciprocated axially of the device and adapted to positively engage the plunger whereby the plunger can be moved axially forward by the drive mechanism and to be disengaged from the plunger to permit relative axial movement between the drive mechanism and the plunger;

ii. a disengagement means for selectively engaging or disengaging the drive means from the plunger;

iii. an actuating means, which may be the integral with or separate from the disengagement means, for actuating the disengagement means, which actuation means requires a positive operation from a user of the device to engage and/or disengage the drive mechanism from the plunger; and

iv. means for individually selecting the extent of travel of the drive mechanism for each actuation of the device so as to control the extent of axial movement, of the plunger upon actuation of the device.

13. A hand portable device for dispensing a fluid from a container by means of the axial movement of a piston within the container under the influence of a plunger moved by the device, which device is adapted to receive the container on its forward end and to move the plunger axially forward towards or within the container so as to dispense a selected amount of fluid from the container upon each actuation of the device, characterised in that the device comprises:

a. an elongated generally cylindrical hollow body member having its forward end adapted to receive and retain the fluid container;

b. a plunger extending axially within said body member and adapted to be moved axially in a series of individually selected increments and to bear against the piston within the container when mounted on the said body member so as to move the said piston to dispense doses of fluid from the container at each incremental movement of the plunger;

c. a radially acting jaw member adapted to be moved into engagement with the said plunger to provide a positive drive connection between said jaw and said plunger, and to be disengaged from said plunger so as to permit relative axial movement between said plunger and said jaw;

d. means requiring positive operation by a user of the device for engaging or disengaging said jaw from said plunger.

e. an axially acting push sleeve journalled upon said plunger for moving said jaw forward when engaged to said plunger;

f. axially acting dosage selection means comprising a screw thread moved sleeve journalled for axial movement upon said push sleeve and carrying demountable means for engaging said jaw when said latter is disengaged from said plunger and for moving it rearwardly from a datum point so as to select the possible extent of forward travel of said plunger and to release said jaw when said jaw is re-engaged with said plunger for axial movement by said push sleeve; and

g. means for rotating said screw sleeve so as to select the extent of rearward movement of said screw sleeve from said datum point.