Disposable syringe

A disposable syringe comprising

• a syringe cylinder having an inside peripheral surface, an open first end and a second end, an end wall at said second end, the end wall being provided with a hollow needle holder and being closed with the exception of the region adjacent to said needle holder,
• a syringe piston comprising a piston skirt that protrudes out of said open first end of said cylinder and is provided with a handle outside said cylinder, and a piston head disposed within said cylinder and facing said second end thereof, the piston head having an end face facing said second cylinder end and carrying a peripheral annular flange that is provided with an annular seal in sliding contact with said inside peripheral surface of said cylinder,
• said end wall of said cylinder having an inside surface which, except adjacent to said needle holder, conforms to said end face of said piston head,
• said flange having a frustoconical inside surface facing said first end of said cylinder and said piston skirt and a frustoconical outside surface facing said inside peripheral surface of said cylinder and said second end of said cylinder,
• said flange flaring toward said first end of said cylinder,
• said inside surface of said flange and said annular seal defining a peripheral annular space which is generally triangular in radial section,
• said end wall of said cylinder comprising a peripheral annular portion which is generally triangular in radial section and conforms to said annular space,
• said needle holder being eccentrically disposed with respect to said end wall and extending through said annular portion and opening into said annular space,
• the radical distance from said frustoconical inside surface to said piston skirt continuously increasing toward said second end of said cylinder, and
• said annular seal being cylindrical and being joined to, and coaxial with, said flange and freely protruding therefrom toward said end wall of said cylinder.