Patent ID: 7819846

Claim:
A syringe piston without a shaft, used in fat transplantation, disposed in a syringe-shaped cylindrical vessel, comprising: a piston body without the shaft; a packing coupled with an outer surface of the piston body to form a seal between the piston body and the syringe-shaped cylindrical vessel; a free oil discharging hole communicated with the front side and the rear side of the piston body; an opening and closing device for opening and closing the free oil discharging hole; a filtering device disposed in a passage through which free oil is discharged to filter fat and pass the free oil, wherein the opening and closing device for opening and closing the free oil discharging hole comprises a first check valve disposed at one side of the free oil discharging hole and a second check valve disposed at the opposite side of the free oil discharging hole and operated by an external force, wherein each of the first and second check valves comprise: a rim which is fixed to the piston body; an opening and closing plate which has a size sufficient to open and close the free oil discharging hole, wherein the opening and closing plate is without any holes; and a connector which connects the rim to the opening and closing plate, wherein the rim is deformed by the external force so that the free oil discharging hole is easily opened and closed.