Patent ID: 8034025

Claim:
A disposable safety syringe comprising: a syringe barrel ( 10 ) having both ends open and comprising a plurality of projections ( 14 ) equally spaced on an inner surface proximate one end ( 12 ), a plurality of axial raised limit members ( 13 ) at one end ( 12 ), and an annular lip ( 15 ) distal the limit members ( 13 ); a plunger ( 50 ) comprising a push rod ( 57 ) projecting out of one end, first locking means ( 55 , 56 ) at a portion of the push rod ( 57 ) joining one end of the plunger ( 50 ), a cylindrical sealing member ( 54 ) at one end of the plunger ( 50 ), a stop ring ( 53 ) abutted the sealing member ( 54 ), a cross shaped cutting groove ( 52 ) adjacent the stop ring ( 53 ), and a thumb pad ( 51 ) distal the sealing member ( 54 ); a hollow first adapter ( 20 ) comprising a hollow, cylindrical body ( 28 ) having a locking member ( 23 ), a hollow cylinder ( 26 ) extending through the body ( 28 ) and being concentric therewith, the cylinder ( 26 ) having a flared rear end ( 27 ), a shoulder ( 29 ) formed between the cylinder ( 26 ) and the body ( 28 ), a plurality of risers ( 22 ) on an outer surface of the body ( 28 ), a plurality of recesses ( 21 ) each defined by the riser ( 22 ) and the body ( 28 ), and a first O-ring ( 25 ) abutted the shoulder ( 29 ); a tubular second adapter ( 30 ) comprising a plurality of latches ( 32 ) each having a raised curved member ( 33 ) at one end, an annular flange ( 31 ) at the other end, and an inward extending rim ( 35 ) at the other end; a tubular third adapter ( 40 ) having a stepped-diameter outer surface and comprising an enlargement ( 47 ) having annular inner wall ( 43 ) at one end, a stepped-diameter section ( 46 ) adjacent the inner wall ( 43 ), second locking means ( 41 , 42 ) at the other end, and a second O-ring ( 45 ) put on the outer surface of the third adapter ( 40 ); wherein in an assembled state, the first adapter ( 20 ) is inserted through the syringe barrel ( 10 ) until the first adapter ( 20 ) is disposed at one end ( 12 ) with the recesses ( 21 ) aligned with the limit members ( 13 ), the first adapter ( 20 ) is pushed to lockingly dispose the limit members ( 13 ) in the recesses ( 21 ), the second adapter ( 30 ) is inserted through the syringe barrel ( 10 ) to put on the cylinder ( 26 ) with the latches ( 32 ) being lockingly urged against the projections ( 14 ), the third adapter ( 40 ) is inserted through the syringe barrel ( 10 ) into a cylindrical space between the cylinder ( 26 ) and the second adapter ( 30 ) until the first O-ring ( 25 ) is clamped by the inner wall ( 43 ) so as to form an airtight engagement of the first, second, and third adapters ( 20 , 30 , 40 ) at one end ( 12 ) with the first, second, and third adapters ( 20 , 30 , 40 ) being secured together.