Patent ID: 8460245
Filing Date: 2013-06-11
Classification: A61M,F16F

Abstract:
1. A device for delivery of medicament, comprising: an elongated housing; a container having a needle mounted within said housing and adapted to contain a liquid medicament; a stopper slidably arranged within said container; actuating means comprising a resilient member, and a plunger rod having a proximal end in contact with the stopper and a distal end being operably connected to the resilient member, a carrier fixedly arranged to an inner surface of the housing and configured not to move relative to the housing; retaining means pivotally arranged to the carrier and comprising a protrusion arranged to be in direct contact with the plunger rod and be positioned in a groove of the plunger rod for releasably retaining the plunger rod in a first position where said resilient member has an accumulated energy, and activating means operably connected to said retaining means for releasing the plunger rod to a second position, upon active operation by an user, such that said accumulated energy is transferred to the plunger rod for driving the plunger rod and the stopper a predetermined axial distance within the container relative to the carrier that is fixed to the housing whereby the medicament within said container is delivered; wherein the activating means comprises a tubular member mounted to the housing and at least one resilient means operably connected to the tubular member; the tubular member comprises an end portion adapted to be retractable with respect to the housing against a force of the resilient means when the end portion is pushed against a delivery site such that the needle is penetrated into the delivery site; the tubular member is adapted to be urged by a biasing force in an extended position in the direction of the end portion by the at least one resilient means when the end portion is removed from the delivery site; the resilient member is not a helical compression spring but is a variable force spring having a first end that is directly connected to the carrier and a second end, which is variably wound, cradled on the second end of the plunger rod; the variable force spring is adapted for generating a predetermined sequence of at least two different force profiles during the medicament delivery; and a last force profile in the sequence is a profile where force increases as the spring relaxes.