SYRINGE

摘要

A syringe (10) comprises: a barrel (14); movable piston means (16); on a front side of the barrel (14) there is provided a movable member (22) accommodating a needle (12); behind the movable member (22) there is a chamber (42) sealing means (20) and restraining means (28). When the piston (16) moves onwards the lower end (52) of the piston (16) engages an upper surface (60) of the restraining means (28) thus deforming an annular structure (36). Remainders of the restraining means are cut off the moving member (22) which is then retracted into the chamber (42) of the piston (16) by excitement of a spring (18) so that the movable member (22) is in this region retained. As a result the syringe can not be reused.