Patent ID: 7927301
Filing Date: 2011-04-19
Classification: A61M

Abstract:
1. A safety syringe comprising: an outer barrel, said outer barrel having a front end and a rear end; a needle unit, said needle unit being disposed within said front end of the outer barrel; an outer barrel plug, said outer barrel plug being disposed within said outer barrel, wherein said outer barrel plug is connected with said needle unit so as to fix said needle unit; an inner barrel, said inner barrel having a front end and a rear end, wherein said inner barrel is inserted in said outer barrel through said rear end of said outer barrel; an inner barrel plug, said inner barrel plug being disposed within said front end of said inner barrel; a needle clamper, said needle clamper being connected with said inner barrel plug, wherein said needle clamper is able to clamp a rear opening of said needle unit; and a vacuum generating device, wherein said vacuum generating device comprises a vacuum plug, said vacuum plug is disposed within said inner barrel, both said vacuum plug and said inner barrel plug are capable of adjusting the volume defined by said vacuum plug, said inner barrel, and said inner barrel plug for generating low air pressure before injection process, the volume is adjusted by the distance between said vacuum plug and said inner barrel plug, and said needle unit can be retracted into said inner barrel by said low air pressure, said low air pressure maintains constant air pressure until said needle unit is retracted into said inner barrel, said vacuum plug is in air-tight contact with said inner barrel whereby when said vacuum plug moves toward said rear end of said inner barrel said low pressure is generated within said inner barrel, said vacuum generating device comprises a connecting rod, said connecting rod is connected to said vacuum plug, said vacuum plug is capable of moving by said connecting rod, said connecting rod comprises a front end and a rear end, said front end of said connecting rod is connected to said vacuum plug, and said connecting rod comprises a breakable portion.