Patent ID: 6921386

Claim:
An intravenous catheter device for use with a disposable syringe which includes a barrel having an inner surrounding barrel wall surface which confines a passage that extends in a longitudinal direction and that has open forward and rearward ends opposite to each other in the longitudinal direction, and an outer surrounding barrel wall surface which has a front surrounding region that is proximate to the open forward end, a needle cannula retractably received in the open forward end, and a plunger which is received in the passage to be movable in the longitudinal direction, which extends outwardly of the open rearward end so as to be manually operable, which has a cavity extending in the longitudinal direction and containing fluid at a reduced pressure, and which is coupled with the needle cannula within the passage such that the needle cannula will be retracted into the cavity once the needle cannula is subjected to a suction force that arises as a result of a pressure difference between the ambient air and the reduced pressure, said intravenous catheter device comprising: a catheter hub including a surrounding tip wall which surrounds an axis, and which confines a through hole extending along the axis, a sleeve wall which is opposite to said surrounding tip wall along the axis, and which has an inner sleeve wall surface that surrounds the axis, and that confines an insert hole larger than said through hole, said inner sleeve wall surface being adapted to be secured relative to the front surrounding region of the outer surrounding barrel wall surface of the barrel so as to bring the passage into alignment with said through hole, and an intermediate tubular wall which is interposed between said surrounding tip wall and said sleeve wall, which confines a duct that communicates said insert hole with said through hole, and that is adapted for the needle cannula to pass through when said inner sleeve wall surface is secured relative to the front surrounding region of the outer surrounding barrel wall surface of the barrel, and which has a communicating port extending therethrough to communicate said duct with ambient air; and a tubular catheter including a proximate segment which is disposed in said through hole and which extends along the axis to communicate with said duct, and a distal segment which extends from said proximate segment along the axis to project outwardly of said surrounding tip wall, and which is adapted to be sleeved on the needle cannula and to permit the needle cannula to extend outwardly thereof, when the needle cannula is brought to pass through said duct.