Patent ID: 6190363
Filing Date: 2001-02-20
Classification: A61M

Abstract:
A self-aligning plunger rod and non-elastomeric plastic plunger insert assembly for use with an elastomeric plunger in a cartridge or syringe barrel for manual or power-assisted withdrawing of fluid from a site or expelling fluid from the cartridge or syringe barrel comprising:a) a plunger rod having a distal end and a proximal end comprising:longitudinal radially extending vanes;a thumb rest at the proximal end;a disc at the distal end; anda plunger rod tip extending from said disc adapted to engage a plastic plunger insert, said plunger rod tip comprising a neck portion and a ball portion, said ball portion having slots therein extending axially from said neck portion;b) a non-elastomeric plastic plunger insert comprising:a cylindrical shaft having a distal end and a proximal end;at least one cylindrical recess between the distal end and the proximal end of said cylindrical shaft adapted to hold an elastomeric plunger having a cylindrical protuberance to engage said cylindrical recess;a cone-shaped head having an inside surface and an outside surface, extending from the distal end of said cylindrical shaft;a cylindrical flange extending from the proximal end of said cylindrical shaft;a first cylindrical rim constituting an underside of said cylindrical flange;a second cylindrical rim adjacent to said first cylindrical rim and projecting slightly above a horizontal surface of said first cylindrical rim;a cavity defined within said second cylindrical rim and the inside surface of said cone-shaped head;a plurality of tabs extending from the second cylindrical rim into said cavity; andnotches between said tabs to receive said slotted ball portion of said plunger rod tip.