Patent ID: 8821439

Claim:
A needle assembly comprising: a needle having a needle shaft and a distal tip, the needle shaft having a change in profile; and a needle guard comprising an elongate arm that extends distally from a base, the base having an aperture formed therein, the needle guard slideably mounted on the needle shaft with the needle shaft passing through the aperture formed in the base, the aperture sized so that a portion of the base circumscribing the aperture engages with the change in profile of the needle shaft to limit a proximal movement of the needle with respect to the needle guard, the elongate arm having a proximal section adjacent the base and a distal section, the needle guard further comprising an elongate member having a through passage extending between an open proximal end and an open distal end of the elongate member, the elongate member extending distally from a position at or near the base and slideable alongside the needle shaft as the needle is moved between a ready position and a retracted position, in the ready position the distal tip of the needle resides distal to the open distal end of the elongate member with a segment of the distal section of the elongate arm being urged against a side of the needle shaft, in the retracted position the distal tip of the needle resides within the elongate member and the elongate member completely circumscribes the distal tip with no portion of the elongate member or any structure attached to the elongate member extending beyond a distal-most portion of the elongate arm, the elongate member having a length such that substantially coincident with the change in profile of the needle engaging the portion of the base circumscribing the aperture in the base the entirety of the distal tip of the needle is positioned to reside within the through passage of the elongate member with the segment of the distal section of the elongate arm disengaged with the needle shaft and the distal section of the elongate arm moved radially inward to at least partially lie over the distal end of the elongate member.