| 摘要 |
A completely disposable, permanently assembled drill for perforating bone structures, which includes a generally annular drill body. A primary drill member is slidably and rotatably received in the distal end of the drill body. A driver is slidably and rotatably received in the proximal end of said drill body. A pin and slot-type spring biased clutch is disposed on the confronting surfaces of the drill member and driver. The pin of the clutch projects through the triangular openings and the sidewall of the drill body so as to limit the throw of the clutch and to link the drill body and drill member together. The interaction of the pin against the triangular side of the slot in the drill body produces a component of force which tends to urge the clutch apart. When the drill is placed against the bone structure with a force sufficient to overcome the spring bias, the clutch will engage and the driver and drill member and the drill body will rotate together. The counterbore on the drill body provides a support for the drill mechanism so that the drill member may release when it penetrates the bone structure without having the remainder of the drill move in the direction toward the cranial cavity. The sleeve holds the drill body and driver together and is made of a material that degrades when subjected to sterilization. |
