A safety needle system has a sheath that is capable of reciprocally sliding over the exterior of a syringe to alternately cover and uncover the needle portion of the syringe. The sheath is locked over the needle by means of a locking slot and coiled spring. A dog on the needle hub engages the locking slot and is held in position in the locking slot by the coiled spring. The sheath is reciprocally slidable on the exterior of the needle of the syringe by twisting the sheath to disengage the dog from the slot and moves the dog into a guide slot so that the sheath can be moved manually to expose the needle.

A self destructive safety syringe assembly having a needle cannula fixed to a slideable piston. The slideable piston and slideable piston flange are held within the first barrel of the syringe assembly by a compressed spring, a guide tube and a shatter ring. The hollow elongated plunger of the syringe assembly is a hollow elongated tube with a thumb flat at one end, a sliding gasket, a plunger shatter plate and a hook rim at the other end. When medicament is injected into a body the elongated hollow plunger is further thrust into the shatter ring, the shatter ring shatters, or breaks or fails further allowing the slideable piston and slideable piston flange to thrust into the plunger shatter plate thus causing the plunger shatter plate to shatter, or fail or break. This action further causes the slideable piston and needle cannual to be thrust into the elongated hollow plunger by the spring and wherein the spring will further prevent the slideable piston and needle cannula from re-entering the guide tube and further rendering the syringe unuseable and completely destroyed internally. The needle cannula is further completely contained within the elongated hollow plunger wherein it cannot touch, prick or injure another or further inject a disease into others.

So as to prevent accidental needle contacts when a syringe device is not being used, I have devised a syringe device in which I have made a movable shield member, integral with a syringe member of said device, to be movably interconnected with the syringe member for movement between a first position for shielding a needle member of said device and a second position for exposing the needle member, I have provided means for manually moving the shield member from the first to the second position, and I have disposed between the shield member and the syringe member, spring means for normally biasing the shield member in the shielding position when the syringe device is not being used.

A safety device for use with a conventional hypodermic syringe including a needle shield for connection to the hypodermic syringe having a tubular housing slidably connected to a retractable needle sheath. The needle sheath is selectively lockable in a retracted position within the tubular housing so that a needle held by the hypodermic extension can be exposed for use. A handle can be used for retracting the needle sheath within the tubular housing to a locked position. A release tab is located on the exterior of the tubular housing for unlocking the needle from the retracted position, and allowing said needle sheath to automatically lock in the closed position.

An attachment for standardized hypodermic syringes which is characterized by a protector tube that slides over the syringe and is secured by a catch spring comprised of a split ring that constricts onto the hub that carries the syringe needle and has resilient legs that engage in the longitudinal slot in the protector tube, a detent at an outer end of the slot for retracted postioning of the protector tube exposing the needle, and a lock shoulder (shoulders) at an inner end of the slot for permanent extended positioning of the protector tube covering the needle.