Abstract: A plunger rod assembly for use with a syringe barrel comprises a plunger rod and a flexible thermoplastic stopper. A plunger rod includes an elongate shaft portion defining a longitudinal axis and having a tapered tip portion at the distal end thereof. The tapered tip portion includes a front portion at the distal end thereof and a circular tapered plunger rod wall connected to the front portion and having a convexly shaped surface. A flexible cup-shaped thermoplastic stopper includes an annular side wall and a continuous front wall connected to the side wall. An exterior surface of the side wall is larger in diameter than the syringe barrel inside diameter. The stopper interior includes an inside surface of the front wall and a tapered annular inside wall connected to the annular side wall and to the inside surface. The tapered annular inside wall and the inside surface define a cavity which has the tapered tip portion received therein.

Abstract: A variable sealing pressure plunger rod assembly for use with a syringe barrel comprises a plunger rod and a flexible stopper. The plunger rod includes a rigid elongate shaft portion having a circular tapered tip portion at the distal end thereof. The flexible cup-shaped stopper includes an annular side wall and a front wall connected to the side wall. An exterior surface of the side wall is larger in diameter than the syringe barrel inside diameter. The stopper interior includes an inside surface of the front wall and a tapered annular inside wall connected to the side wall and to the inside surface. This tapered annular inside wall and the inside surface define a cavity which has the tapered tip portion received therein. The tapered annular inside wall and the tapered tip portion are inclined at approximately the same angle and adjacent to each other. Cooperating structure for maintaining the positional relationship of the stopper and the plunger rod is also provided.

Abstract: A multiple blood sampling device is disclosed together with its method of manufacture. The device includes a housing having a chamber therein, a first cannula attached to one end of the housing, a second cannula attached to the other end of the housing, and a one-way valve provided within the housing. Part of the housing is molded around a portion of the valve to securely hold it in place. Another portion of the valve extends into the chamber where it provides valving action in response to the relative pressures in to two cannulas. When one cannula penetrates the blood vessel of a patient and the other punctures the stopper of an evacuated tube, blood is able to flow through the device and into the tube. Backflow is prevented by the one-way valve.

Abstract: A multiple blood sampling device includes a housing having a chamber therein, a first cannula attached to one end of the housing, a second cannula attached to the other end of the housing, and a one-way valve provided within the housing. Part of the housing is molded around a portion of the valve to securely hold it in place. Another portion of the valve extends into the chamber where it provides valving action in response to the relative pressures in to two cannulas. When one cannula penetrates the blood vessel of a patient and the other punctures the stopper of an evacuated tube, blood is able to flow through the device and into the tube. Backflow is prevented by the one-way valve.