Patent ID: 7993307

Claim:
A safe medical syringe with an automatic slowly retractable needle, comprising: a hollow barrel; a plunger installed inside the hollow barrel, the plunger comprising a push tube and a rubber plunger on a distal end of the push tube; a hub provided on a distal end of the barrel, the hub a comprising (1) an elastic connecting hub portion that is retractable into the push tube and that houses an end of an injection needle and (2) a hub sheath surrounding the elastic connecting hub portion; a spring set disposed between the elastic connecting hub portion and the hub sheath, and providing a springing force in an axial direction between the hub sheath and the elastic connecting hub portion, the elastic connecting hub portion breaking away from the distal end of the barrel after injection and drawing back into the push tube by the springing force of the spring on the elastic connecting hub portion; and a slow retraction device cooperating with, and corresponding to a longitudinal axis of, the elastic connecting hub portion, the slow retraction device comprising (1) a backup washer and a slow retraction bracket joined together to form the slow retraction device, and (2) at least two elastic bracing claws that press outwardly and slidably interact with an inner wall of the push tube creating a frictional resistance against the inner wall of the push tube to slow the retraction of the slow retraction device.