Patent ID: 7896850
Filing Date: 2011-03-01
Classification: A61M

Abstract:
1. A device for delivering predetermined doses of liquid medicament, the device having a medicament delivery state and a medicament non-delivery state and comprising: a cartridge housing including a cartridge configured to contain the liquid medicament and a piston sealingly and slidably arranged in the cartridge; a proximal part having a thread in its exterior surface, and a distal part including a dose setting member having a thread in its interior surface and configured to be screw-threaded on the proximal part to set a dose volume; an energy accumulating member configured to accumulate energy when the device is in the medicament non-delivery state; an elongated threaded plunger rod configured to be screwed into the cartridge housing, wherein a proximal end of the plunger rod is configured to be in contact with the piston, such that, when energy accumulated by the energy accumulating member is transferred to the plunger rod when the device is in the medicament delivery state, the plunger rod and the piston move toward a proximal end of the cartridge by a predetermined distance and expel a dose of the liquid medicament from the cartridge; and a further energy accumulating member configured to accumulate further energy when the dose setting member moves linearly along the exterior surface of the proximal part of the device which is provided with a remaining dose indicator and wherein the device becomes shorter; wherein the further energy accumulating member is configured to transfer further energy to the plunger rod so that the plunger rod is provided with a torque that helps to drive the plunger rod and the piston the predetermined distance toward the proximal end of the cartridge when the device is in the medicament delivery state.