| 摘要 |
An instrument (1) including an elongate handle (2) with an end portion (4) slidably housing a shaft (6) provided at the end thereof with an upside-down frusto-conical tip (6a). When the tip (6a) is placed at the end of a screw (13) with a ring-shaped groove (14) engageable by a circlip (11) pre-positioned at the base of said tip (6a), longitudinal pressure may be exerted on the instrument to retract the tip (6a) into the end portion (4) counter to a return spring (8). As the tip (6a) is retracted, the circlip (11) slides over the tapering surface of the tip (6a) and is thus opened out so that it passes onto the end of the shaft of the screw (13). Exerting further pressure on the instrument (1) moves the circlip (11) into the ring-shaped groove (14) of the screw (13). The end of the tip (6a) includes a tapered recess (15) engaged by the tapered end (13a) of the screw (13), whereby said tip (6a) and said shaft of the screw (13) are held in perfectly coaxial positions. |
