Ribbon cartridge structure for printing head of large color printer

A ribbon cartridge structure for a printing head of a large printer comprising:

• a ribbon cartridge provided with an “L” shaped sheet member of which the two ends are respectively extended to connect with two cylinders being each provided centrally with a rotation axle, and being provided on the peripheries thereof each with an opening for extending of a color ribbon therethrough, said an “L” shaped sheet member is provided on both sides thereof with at least one engaging portion;
• an inner clamping piece being a curved rectangular sheet, said inner clamping piece is provided on one side thereof with at least one protruding portion and is provided on the other side thereof with at least one hooking portion to connect with the corresponding ones of said engaging portions on both sides of said “L” shaped sheet member;
• an external clamping piece being a curved rectangular sheet, it is disposed in an external and inner positional correlation with said inner clamping piece, said external clamping piece is provided on one side thereof with at least one protruding portion and is provided on the other side thereof with at least one hooking portion to connect with the corresponding ones of said engaging portions on both sides of said “L” shaped sheet member;
• said color ribbon extends through the space between said external and said inner clamping pieces.