ASPIRATING PLUNGER FOR POWER INJECTOR CARTRIDGES

摘要

A self-aspirating hypodermic cartidge (1) which contains an injectable fluid therein comprising a generally cylindrical barrel (3) having a wall, and plunger reciprocable in said barrel to aspirate the cartridge (1) and to expel said injectable fluid therefrom said plunger comprising: a female ring component, with a vertically oriented cylindrical hole having a cylindrical flat bottom portion, a cylindrical flat portion spaced from said cylindrical flat bottom portion, and a side portion (46) connecting said cylindrical bottom and top portions and integral therewith, said side portion having a degree of incline with respect to a horizontal plane of from about 1o to about 89o; a mushroom-shaped male component having cylindrical plunger shaft (52) slideably positioned into said female ring component, and a cone-shaped head at one end of the shaft and integral therewith having a degree of incline with respect to a horizontal plane of from about 1o to about 89o; and an elastomeric diaphragm-shell (44) having a cylindrical bottom portion and a generally cone-shaped side portion integral therewith covering said male and female components, said cylindrical bottom portion being adapted to form a slideable seal between the female ring component and the wall of the cylindrical barrel, and said cone-shaped side portion being adapted to serve as a diaphragm whereby upon alternate exertion of pressure upon said plunger shaft and release thereof the deformation of the diaphragm reduces head space in the cylindrical barrel thereby expelling head space gas and upon release of pressure the diaphragm returns to its original shape resulting in aspiration.