Hypodermic needle assembly with retractable needle cover

Abstract

A disposable hypodermic needle assembly is disclosed which includes a permanently attached but retractable covering means for the forward portions of the needle. The assembly comprises a hub portion adapted for attachment to the outlet end of a syringe, the hub portion including a central passageway for enabling liquid flow to or from the syringe. A hollow needle is connected to the hub with its inlet end communicating with the central passageway of the hub. An annular slide member surrounds and is longitudinally slideable with respect to the needle, the member being positionable to normally cover the forward portion of the needle. A plurality of elastically resilient arms extend between the hub portion and slide member. The said arms, which may e.g. comprise plastic strips, act to normally maintain the slide member in its position covering the forward portion of the needle. The arms are bowable away from the longitudinal axis of the needle upon the slide member being urged toward the hub portion by contact of the slide member with the skin of a patient during injection of the needle. The outward bowing of the elastically resilient arms generate a restoring force urging the slide member back over the forward needle portion upon withdrawal of the assembly from contact with the skin. The assembly may also include a slideable locking ring member, which in one position embraces and constrains the arms, to thereby lock the slide member against rearward movement.

Dependencies are inferred from the claim text.