| 摘要 |
<p>An injection needle retractable injector, comprising a barrel having a plunger inserted into a hollow formed therein, a needle base (3) fitted to the tip part of the barrel, a hub (2) fitted to a hollow in the needle base so as to be separated only to a rear end side, and an injection needle (4) having a rear end part fixed to the tip part of the hub, wherein the plunger is moved to the tip part of the barrel to engage the rear end part (11a) of the hub with the tip part (13) of the plunger so that the injection needle can be pulled into the barrel through the plunger, the hub is held in the needle base by a fitting structure formed between the tip part outer peripheral surface of the hub and the tip part hollow surface of the needle base, and the tip of the hub in the fitted state of the hub being positioned at the outermost side of the needle base is positioned near or forward of the tip of the needle base in axial direction, whereby a production can be facilitated, the effect of an external force acting on the fitting structure between the hub and the needle base can be suppressed, and a fitting strength can be maintained satisfactorily.</p> |
