Syringe plunger tip

摘要

A sealing cap is provided for attachment to the end of a syringe plunger. The sealing cap has an annular sidewall with an annular first sealing wing projecting distally therefrom, an annular second sealing wing positioned proximal of the first sealing wing and projecting proximally, and an annular sealing ridge encircling and radially projecting out from between the first sealing wing and the second sealing wing. The sealing cap further includes an interior cavity having an annular side surface aligned with the annular sidewall. A side groove is recessed within the side surface so as to be aligned slightly proximal of the annular sealing ridge. The distal end of a syringe plunger has a head mounted thereon that is substantially complementary to the configuration of the internal cavity of the sealing cap. More specifically, a tapered ridge is formed on the periphery of the head to complementarily be received within the side groove. As a positive pressure is created against the sealing cap, the first sealing wing flexes against the interior surface of the barrel and the annular sealing ridge urges against the interior surface of the barrel, thereby increasing the effective seal. As a negative pressure is formed within the barrel, the second sealing wing flexes against the interior surface of the barrel to increase the effective seal.