Safety retracting needle for use with syringe

Abstract

A hollow needle projects from the 'forward' end of a hollow handle. A syringe communicates with the interior of the needle by way of the hollow handle. After use for passing liquid between the syringe and a patient's body, the needle is released from the handle and its sharp end retracted into the handle, beyond reach. The handle has an aperture big enough for the needle but not for fingertips. The needle rides in a carrier block that slides inside the handle. Initially the block is secured in the handle against the forward end, with the sharp end of the needle protruding out through the aperture. A manually releasable latch holds the block in this position. The latch includes mutually interfering stop elements on the exterior of the block and interior of the handle. After liquid is injected into or withdrawn from the patient's body, the person using the device withdraws the needle from the patient and manually triggers the carrier-block latch by squeezing or rotating one stop element out of engagement with the other. Then a coiled spring drives the block rearward to retract the needle into the handle. At the rear of the handle a stop halts the block and needle to safely confine them within the handle. A standard-size fitting on the rear of the handle permits liquid flow between the patient and a standard syringe with a standard front fitting.