| 摘要 |
A hypodermic needle has a hub that is substantially equal in length to or longer than the length of the needle. A sliding cover, of the order of the length of the extended hub, is sized to make a sliding fit on the hub and to be supported by the hub when it slides. A detent in the inside of the cover engages a groove in the elongated hub that is axial and in the surface of the hub to guide the cover. In the alternative, the detent may be in the hub and the cover may be grooved. The groove has circumferential portions at either end to lock the sliding cover in a closed position to protect the needle point and in an open position to permit use of the needle as a hypodermic. An additional cover is provided which is adapted to engage the hub and envelope the sliding cover and needle. |
