Abstract: A single-use hypodermic syringe has barrel (10) and needle holder (20) with a needle receiving passage. The needle holder is detachably mounted in the barrel and defines annular space (30) with the barrel communicating with the needle receiving passage. Piston (32) is mounted in annular space (30) and piston rod (38) is connected to the piston with an amount of lost motion. Needle holder (20) is connectable to the piston rod by means of elastically mounted projection (26) engageable with projection (50) of the piston rod. The amount of the lost motion is greater than the total of the axial lengths of projections (26, 50) of piston rod (38) and needle holder (20).

Abstract: A single-use syringe has piston (18) mounted in barrel (10) and detachably connected to piston rod (30) though its internal projection (26) engaged by outer projection (36) of elastic leg (34) of the piston rod. Sliding member (48) is mounted in the piston and has cam portion (50). The inside diameter (d) of the sliding member is smaller than the diameter (D) of inside radial face (44) of the internal projection of the piston. The axial length (1) of cam portion (50) of the sliding member is smaller than the axial length (L) of the outer projection of elastic leg (34).