Measured dose dispensing device

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.

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.

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.