ACTIVE SAFETY PEN NEEDLE ASSEMBLY

摘要

The subject invention provides a safety pen needle assembly which includes: a hub; a needle carrier; a needle fixed to the needle carrier; a shield; and, a first engageable locking arrangement for fixing the shield to the needle carrier. Upon a predetermined extent of distal movement of the shield relative to the hub, the first locking arrangement is engaged such that the shield becomes fixed to the needle carrier. Upon further distal movement of the shield relative to the hub beyond the predetermined extent of distal movement, the shield and the needle carrier move in concert together relative to the hub causing a proximal end of the needle to move distally relative to the hub to a retracted state. Advantageously, the subject invention provides a reliable, low-cost safety pen needle assembly which does not require a spring or other biasing element.