Self-blunting needle assembly for use with a catheter, and catheter assembly using the same

A self-blunting needle assembly for use with a catheter having a hub within which is formed a hub chamber, and a catheter tube extending from the hub and terminating in a tube tip, the tube having a tube bore extending therethrough, the needle assembly comprising:

• (a) a needle member in which is mounted a blunting member,
• (i) the needle member comprising a needle shaft having a needle bore extending therethrough, the needle shaft terminating at one end in a puncture tip and having an opposite, proximal end on which is carried a connector means,
• (ii) the blunting member comprising an elongate probe having a retainer means carried thereon, the probe being slidably mounted within the needle bore with the retainer means carried exteriorly of the needle bore and in engagement with the connector means,
• (iii) the needle member being axially movable relative to the blunting member, from a retracted condition of the blunting member, in which the probe is short of the puncture tip, to an extended condition of the blunting member, in which the probe protrudes outwardly of, and thereby blunts, the puncture tip of the needle member;
• the retainer means being dimensioned and configured to be force-fit within the hub chamber of a catheter to hold the needle assembly in place within such catheter and so positioned that (1) the needle shaft would be disposed within the tube bore of such catheter with the puncture tip thereof extending outwardly of the tube tip of such catheter, and (2) the needle member would be accessible from exteriorly of such catheter at the hub thereof;
• the retainer means and the connector means being dimensioned and configured to provide a lost motion connection between the needle member and the blunting member, whereby an initial stage of withdrawal of the needle member from such catheter moves the needle member relative to the blunting member to change the blunting member from its retracted condition to its extended condition, thereby blunting the needle, and continued withdrawal of the needle member beyond the initial stage overcomes the force-fit between the retainer means and the hub chamber of such catheter and extracts the needle assembly from such catheter, wherein the connector means comprises a ferrule slide and the retaining means comprises a clamping member which imposes a pressure grip on the ferrule slide, whereby the lost motion is attained by overcoming the pressure grip to slide the ferrule slide through the clamping member.

A catheter assembly comprising:

• (a) a catheter having a hub within which is formed a hub chamber, and a catheter tube extending from the hub and terminating in a tube tip, the tube having a tube bore extending therethrough;
• (b) a needle assembly carried by the catheter and comprising a needle member in which is mounted a blunting member,
• (i) the needle member comprising a needle shaft having a needle bore extending therethrough, the needle shaft terminating at one end in a puncture tip and having an opposite, proximal end on which is carried a connector means,
• (ii) the blunting member comprising an elongate probe having a retainer means carried thereon, the probe being slidably mounted within the needle bore with the retainer means carried exteriorly of the needle bore and in engagement with the connector means,
• (iii) the needle member being axially movable relative to the blunting member, from a retracted condition of the blunting member, in which the probe is short of the puncture tip of the needle member, to an extended condition of the blunting member, in which the probe protrudes outwardly of, and thereby blunts, the puncture tip;
• the retainer means being force-fit within the hub chamber to hold the needle assembly in place within the catheter and so positioned that (1) the needle shaft is disposed within the tube bore with the puncture tip thereof extending outwardly of the tube tip, and (2) the needle member is accessible from exteriorly of the catheter at the hub;
• the retainer means and the connector means being dimensioned and configured to provide a lost motion connection between the needle member and the blunting member, whereby an initial stage of withdrawal of the needle member from the catheter moves the needle member relative to the blunting member to change the blunting member from its retracted condition to its extended condition, thereby blunting the puncture tip, and continued withdrawal of the needle member beyond the initial stage overcomes the force-fit between the retainer means and the hub chamber and extracts the needle assembly from the catheter.

A self-blunting needle assembly for use with a catheter having a hub within which is formed a hub chamber, and a catheter tube extending from the hub and terminating in a tube tip, the tube having a tube bore extending therethrough, the needle assembly comprising:

• (a) a needle member in which is mounted a blunting member,
• (i) the needle member comprising a needle shaft having a needle bore extending therethrough, the needle shaft terminating at one end in a puncture tip and having an opposite, proximal end on which is carried a connector means,
• (ii) the blunting member comprising an elongate probe having a retainer means carried thereon, the probe being slidably mounted within the needle bore with the retainer means carried exteriorly of the needle bore and in engagement with the connector means,
• (iii) the needle member being axially movable relative to the blunting member, from a retracted condition of the blunting member, in which the probe is short of the puncture tip, to an extended condition of the blunting member, in which the probe protrudes outwardly of, and thereby blunts, the puncture tip of the needle member;
• the retainer means being dimensioned and configured to be force-fit within the hub chamber of a catheter to hold the needle assembly in place within such catheter and so positioned that (1) the needle shaft would be disposed within the tube bore of such catheter with the puncture tip thereof extending outwardly of the tube tip of such catheter, and (2) the needle member would be accessible from exteriorly of such catheter at the hub thereof;
• the retainer means and the connector means being dimensioned and configured to provide a lost motion connection between the needle member and the blunting member, whereby an initial stage of withdrawal of the needle member from such catheter moves the needle member relative to the blunting member to change the blunting member from its retracted condition to its extended condition, thereby blunting the needle, and continued withdrawal of the needle member beyond the initial stage overcomes the force-fit between the retainer means and the hub chamber of such catheter and extracts the needle assembly from such catheter.