Self-blunting needle assembly and device including the same

A self-blunting needle assembly device suitable for attachment to a fluid flow means comprises:

• (a) a needle member terminating in a puncture tip and having a needle bore extending therethrough and defining a fluid flow path extending through the needle to the puncture tip;
• (b) a blunting member comprising an elongate probe having associated therewith transfer means comprising a piston form which the probe axially extends, the blunting member being mounted with its piston disposed in the fluid flow path, whereby liquid flowing through the flow path acts on the piston to move the blunting member axially along the needle bore from a retracted position in which the probe is short of the puncture tip to an extended position in which the probe protrudes outwardly of, and thereby blunts, the puncture tip, the probe being dimensioned and configured to be accommodated within the needle bore while leaving the bore open to fluid flow therethrough;
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• (c) locking means dimensioned and configured to engage the blunting member and retain it in its extended position.

A self-blunting needle assembly device suitable for attachment to a fluid flow means comprises:

• (a) a needle member terminating in a puncture tip and having a needle bore extending therethrough and defining a fluid flow path extending through the needle to the puncture tip, the needle member having a mouth dimensioned and configured to attach the needle assembly in fluid flow communication to a fluid transfer means;
• (b) a blunting member comprising an elongate probe having associated therewith transfer means comprising a position from which the probe axially extends, the blunting member being mounted with its piston disposed in the fluid flow path, whereby liquid flowing through the flow path acts on the piston to move the blunting member axially along the needle bore form a retracted position in which the probe is short of the puncture tip to an extended position in which the probe protrudes outwardly of, and thereby blunts, the puncture tip, the probe being dimensioned and configured to be accommodated within the needle bore while leaving the bore open to fluid flow therethrough;
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• (c) locking means comprising a cylindrical thimble within which the piston is mounted for axial movement, said locking means being disposed within the needle mouth and being dimensioned and configured to engage the blunting member and retain it in its extended position.

A self-blunting needle assembly device suitable for attachment to a fluid flow means comprises:

• (a) a needle member terminating in a puncture tip and having a needle bore extending therethrough and defining a fluid flow path extending through the needle to the puncture tip;
• (b) a blunting member comprising an elongate probe having associated therewith transfer means comprising a piston from which the probe axially extends, the blunting member being mounted with its piston disposed in the fluid flow path, whereby liquid flowing through the flow path acts on the piston to move the blunting member axially along the needle bore from a retracted position in which the probe is short of the puncture tip to an extended position in which the probe protrudes outwardly of, and thereby blunts, the puncture tip, the probe being dimensioned and configured to be accommodated within the needle bore while leaving the bore open to fluid flow therethrough;
• (c) locking means dimensioned and configured to engage the blunting member and retain it in its extended position;
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• (d) a pressure chamber within which the piston is mounted, the pressure chamber being in flow communication with (i) at least one chamber inlet passage to admit fluid from the needle member into the pressure chamber and (ii) with at least open chamber outlet passage to permit fluid to escape from the pressure chamber, the inlet and outlet passages having respective flow diameters dimensioned and configured to increase fluid pressure within the pressure chamber so as to drive the blunting member from its retracted position to its extended position.

A self-blunting needle assembly device suitable for attachment to a fluid flow means comprises:

• (a) a needle member terminating in a puncture tip and having a needle bore extending therethrough and defining a fluid flow path extending through the needle to the puncture tip;
• (b) a blunting member comprising an elongate probe having associated therewith transfer means comprising a piston having piston flow passages extending therethrough, the blunting member including a probe bore extending therethrough to define at least a segment of the fluid flow path through the needle member, the blunting member being mounted within the needle member for movement of the probe by the piston axially along the needle bore from a retracted position in which the probe is short of the puncture tip to an extended position in which the probe protrudes outwardly of, and thereby blunts, the puncture tip, the probe being dimensioned and configured to be accommodated within the needle bore while leaving the bore open to fluid flow therethorugh;
• (c) locking means dimensioned and configured to engage the blunting member and retain it in its extended position;
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• said needle having a needle mouth having a floor, the piston being mounted within the needle mouth for seating on the floor thereof when the blunting member is in its extended position, and the piston having a stop member projecting axially from the probe side thereof to space the piston flow passages from the floor when the blunting member is in its extended position.

In a hypodermic syringe device comprising (i) a hollow needle member having a shank which terminates in a puncture tip and through which a needle bore extends, (ii) a barrel member providing a liquid reservoir and connected in fluid flow communication with the needle member, and (iii) pressurizing means to impel fluid comprising a liquid along a fluid flow path including the barrel member and the needle bore, the improvement comprising:

• (a) a blunting member comprised of an elongate probe having a transfer means associated therewith, the probe being dimensioned and configured to be accommodated within the needle bore while leaving the bore open to liquid flow therethrough, the blunting member being mounted in the device for movement of the probe by the transfer means axially along the needle bore from a retracted position in which the probe is short of the puncture tip to an extended position in which the probe protrudes outwardly of, and thereby blunts, the puncture tip;
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• (b) locking means dimensioned and configured to engage the blunting member and retain it in its extended position;
• the transfer means comprising an extension member mounted within the needle member to transfer mechanical force applied to the extension member to the blunting member for movement thereof to its extended position, the extension member being separate from and independent of the blunting member and slidably mounted in alignment with the blunting member for movement into engagement therewith to move the blunting member from its retracted to its extended position.

A self-blunting needle assembly device comprises:

• (a) a needle member terminating in a puncture tip and having a needle bore extending therethorugh and defining a fluid flow path extending through the needle to the puncture tip;
• (b) a blunting member comprising an elongate probe having transfer means associated therewith, the blunting member being mounted within the needle member for movement of the probe by the transfer means axially along the needle bore from a retracted position in which the probe is short of the puncture tip to an extended position in which the probe protrudes tip to an extended position in which the probe protrudes outwardly of, and thereby blunts, the puncture tip, the probe being dimensioned and configured to be accommodated within the needle bore while leaving the bore open to fluid flow therethrough;
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• (c) locking means carried within the needle member and dimensioned and configured to engage the blunting member and retain it in its extended position.