Patent ID: 8845592
Filing Date: 2014-09-30
Classification: A61M

Abstract:
1. A medicament delivery device, comprising: a front housing and a rear housing connected to each other; a medicament container disposed within the front housing and having a front opening for a delivery member for delivering medicament therethrough and at least one movable stopper; a compression spring having a predetermined compressed length and a predetermined outer diameter, wherein the compressed length is the length of the spring when the spring is in a pre-tensioned state; a first guide mechanism, comprising a front part having a predetermined first length, a middle part having a predetermined second length, and a rear part having a predetermined third length that corresponds to the predetermined compressed length of the compression spring, wherein the first part extends from a front tip of the first guide mechanism to a front end of the middle part, the middle part extends from a rear end of the front part to a front end of the rear part, the rear part extends from a rear part of the middle part to a rear tip of the guide mechanism, the front tip of the front part is arranged to be in contact with the movable stopper, the middle part comprises an annular ledge and a first lock-release device, and the rear part is fully surrounded by the compression spring when the spring is in the pre-tensioned state such that the spring in the pre-tensioned state extends from the rear tip of the rear part to the rear end of the middle part; and a second guide mechanism, comprising a generally tubular inner wall of the rear housing having a predetermined fourth length, a rear end surface, a predetermined inner diameter, and a second lock-release device, wherein the predetermined fourth length corresponds to the predetermined third length and the predetermined second length together, and the predetermined inner diameter is larger than the predetermined outer diameter of the compression spring, such that the compression spring is fully arranged inside the second guide mechanism between the rear end surface and the annular ledge when the spring is in the pre-tensioned state.