Abstract: The present invention discloses a mechanism for tilting a retractable needle, in which a needle adapter housed within a barrel comprises a connecting tube with a receiving groove on inner wall. The connecting tube forms a rectangle hole on the wall, and a cantilever with at least one tongue is formed between the rectangle hole and the rear portion of the connecting tube. The plunger fitted in the barrel comprises an extruding ring at a front end thereof. When the plunger is pushed forwardly into the connecting tube of the needle-adapter, an exterior ring of the plunger connected to with a piston will force the tongue to bend the cantilever toward the center of the open area, and engage the extruding ring into the receiving groove. When the plunger is pulled backward, the needle-adapter and the needle will be retracted into the barrel. Meanwhile, the needle will tilt as the tongue is forced against exterior ring by the cantilever, and the needle point is therefore close to the inner wall of the barrel.

Abstract: A safety syringe includes a barrel, a connector securely seated in the barrel, and a movable plunger mounted in the barrel and movable to withdraw together with the connector. Thus, when the plunger is pushed into the tube-shaped body of the connector, the connector will be hooked to the distal end of the plunger. Then the connector together with the needle will be pulled into the inside of the barrel when the plunger is withdrawn.

Abstract: The present invention provides a retractable safety syringe, which comprises a barrel, a sleeve, a connector, a plunger and a standard needle. The barrel is a hollow tube for fitting the sleeve at the front end. The connector is fitted in the sleeve and connected to the standard needle. The plunger is fitted in the rear lumen of the barrel for delivering fluid and retracting the connector with the standard needle into the barrel. The sleeve has twin-twisted threads on its inner surface and is integrated with a ring seal on its rear end by thermal melting. The connector is formed integrally by a cone-shaped cylinder and a tub-body, wherein the tub-body can be engaged with the plunger so as to retract the standard needle with the connector into the barrel by pulling the plunger. In the present invention, the barrel, the sleeve and the connector are separated. In use, the cone-shaped cylinder is tightly held with the standard needle by screwing the standard needle clockwise.