Conveniently carried frequent use auto-injector with improved cap structure

摘要

A stressed spring assembly for providing an operative stroke in cooperating relation with a medicament cartridge assembly of an auto- injector so as to inject a liquid medicament of the medicament cartridge assembly through a hypodermic needle of the medicament cartridge assembly into an injection site of the user. The stressed spring assembly includes a cap structure serving the plural purposes of (1) facilitating the securement of the cap structure and remainder of the auto-injection with the user's pocket, (2) alleviating the likelihood of an unwanted release of the releasable mechanism of the stressed spring assembly with a resultant unwanted movement of the hypodermic needle and an unwanted movement of the liquid medicament outwardly of the hypodermic needle by requiring two different manual movements for its removal, and (3) protecting against an unwanted contact with the hypodermic needle while in extended operative position after withdrawal from the injection site. The cap structure is formed of first and second members disposed in a fixed assembled position with respect to one another into which the first and second members are snap-fitted by a relative movement toward one another in an axial direction. Both members are of a configuration enabling them to be molded by corresponding die surfaces contained on two die members movable together and apart.