DEVICE FOR DELIVERING A MEDICAMENT
A device for delivery of medicament, which device comprises an elongated housing; a container ( 4 ) mounted within said housing and adapted to contain liquid medicament; a stopper slidably arranged within said container; and actuating means comprising a resilient member ( 60 ), a driving means ( 50 ) having one end connected to the stopper and a second end being operably connected to the resilient member, retaining means ( 40 ) for releasably retaining said driving means in a first position where said resilient member has an accumulated energy, and activating means operably connected to said retaining means for releasing said driving means to a second position, upon actively operation by an user, such that said accumulated energy is transferred to the driving means for driving the stopper a predetermined distance within the container whereby the medicament within said container i delivered characterized in that the resilient member is a variable force spring adapted for generating a predetermined sequence of at least two different force profiles during the medicament delivery.
1 . A device for delivery of medicament, comprising:
an elongated housing;
a container mounted within the housing and having a slidable stopper contained within and configured to contain a liquid medicament;
a plunger rod having a distal end and a proximal end in contact with the stopper:
at least two variable force springs where one of the springs has a first end that is connected to a carrier axially fixed to the housing and a second end that is variably wound on the distal end of the plunger rod; and
a retainer pivotally arranged to the carrier and comprising a protrusion positioned in a groove on the plunger rod for releasably retaining the plunger rod in a first position where the variable force springs have accumulated energy, where the retainer is configured to release the plunger rod to a second position, upon active operation by a user, such that the accumulated energy is transferred to the plunger rod for driving the plunger rod and the stopper a predetermined axial distance within the container whereby the medicament within said container is delivered.
2 . The device of claim 1 where the variable force springs are arranged in a laminate configuration.
3 . The device of claim 1 where at least one of the variable force springs is adapted for generating a predetermined sequence of at least two different force profiles during the medicament delivery.
4 . The device of claim 1 where each of the variable force springs is adapted for generating a predetermined sequence of at least two different force profiles during the medicament delivery.
5 . The device of claim 3 where the variable force spring with the at least two different force profiles has a profile where force increases as the spring relaxes.
6 . The device of claim 4 where all variable force springs have a profile where force increases as the springs relax.
7 . The device of claim 1 where each of the variable force springs have a thickness t and are arranged relative to each other to have an effective thickness equal to the sum of each t.
8 . The device of claim 1 where the variable force springs are arranged in a side-by-side configuration.