Retractable catheter introducer structure

A method of assembling a catheter introducer structure comprising the steps of:

• a. providing a retractable needle holder having an elongate body in front and a head in back, said head being radially enlarged relative to the body and having an outwardly facing surface, said head further having a flash chamber wherein said flash chamber is attached to and extends rearwardly from the head of the needle holder;
• b. providing a spring mountable around said body under said head;
• c. providing a ring member having an inwardly facing surface mountable on the head with the inwardly facing surface in releasable gripping contact with the outwardly facing surface of the head, the ring member having an outwardly facing surface configured to slidingly grip a tubular wall surface;
• d. providing an elongated housing having a front and a hollow forward portion comprising a spring chamber to receive a spring and the elongated body portion of the needle holder, said housing having a longitudinally extending wall extending rearwardly from said forward portion comprising an interior wall surface forming a tube chamber having an open ended tubular cavity within;
• e. providing a tube having a retraction cavity within and being mountable for movement within said tube chamber, said tube having an open mouth configured to contact the ring member and push it off the head;
• f. releasably mounting the ring member in place upon the head of the needle holder;
• g. introducing the spring followed by the needle holder into containment within the tube chamber with the spring circumscribing the needle holder body below the head;
• h. pushing the combined needle holder and ring into the hollow forward portion of the housing to a forward position of use while compressing the spring wherein the outwardly facing surface of the ring member in slidable gripping contact with the tubular wall surface inside the tube chamber holds the needle holder in place with the needle extended from the housing in a position for use and;
• positioning the tube in the housing with at least part of said flash chamber within said tube.

A catheter introducer structure comprising:

• an elongate catheter needle having a point in front and a back end portion;
• a retractable needle holder surrounding the back end portion of the needle, the needle holder having an elongate body in front and a head in back, said head being radially enlarged relative to the body and having an outwardly facing surface;
• said head further including a flash chamber in fluid communication with the needle, said flash chamber being attached to and extending rearwardly from the head of the needle holder;
• a spring mounted on said elongate body under said head;
• a ring member removably fixed on the head, the ring member having an inwardly facing surface in gripping contact with the outwardly facing surface of the head and an outwardly facing surface configured to slidingly grip a tubular wall surface;
• an elongated housing having a front and a hollow forward portion adapted to receive the elongate body of the needle holder with the needle extended through said front and said needle holder grounded in the front portion of the housing against forward movement relative to the housing;
• said elongated housing having a longitudinally extending wall extending rearwardly from said forward portion and forming a tubular wall surface and an open ended tubular cavity within;
• the outwardly facing surface of the ring member slideably gripping the tubular wall surface within the housing with the needle holder and compressed spring positioned within said front portion of the housing and the needle extended from the front of the housing for use;
• a tube forming a retraction chamber within, the tube being mounted for reciprocation within the tubular cavity of the housing, the tube having an open mouth in front which is configured to push the ring member from the needle holder without driving the needle forward;
• a catheter attachment assembly mounted on the forward portion of the housing with a catheter tube slidingly mounted on the needle;
• and
• whereby the ring member is removed off the head of the needle holder by a forward push on the tube relative to the elongated housing wherein the needle holder is retracted into the tube in response to a spring force and the needle is drawn into the housing to prevent needle sticks after use.

A catheter introducer structure comprising:

• a needle having a point in front, a back end portion and an intermediate portion therebetween;
• a retractable needle holder surrounding the back end portion of the needle, the needle holder having an elongate body comprising a front portion, an intermediate body portion and a head behind the intermediate portion, said head being radially enlarged relative to the intermediate body portion;
• a plunger tube having a hollow body with a landed front opening concentrically and releaseably engaging the head of the needle holder in alignment therewith;
• a housing having a forward portion and a body portion extending rearwardly therefrom with an interior wall surface defining a stepped opening therethrough;
• said housing forward portion concentrically surrounding said needle holder body at one stepped portion of the stepped opening while said body portion concentrically surrounds the combined head of the needle holder and said landed front opening of the plunger tube at another stepped portion, said body portion frictionally holding said landed front opening at the interior wall against a retraction force of a spring compressed under the head of the needle holder, with the needle extended for use;
• and
• wherein said needle holder is released from the landed opening by sliding the plunger tube forward relative to the needle holder within said another stepped portion whereby the landed opening is disengaged from the head of the needle holder which is retracted into the plunger tube while the needle is withdrawn into the housing thereby preventing needle sticks after use.