Screwdriver for socket-head, surgical bone screws, has spring-loaded side-spreading component integrated into driver bit, which is retracted by pulling on handle flange

摘要

A spreader (11) is biased by a spring (16), towards the free end (4) of the shaft (3). It (11) can be pulled back into the shaft against the spring action, until it no longer projects out to the side, from the shaft contour. There is a stop which limits forward travel of the spreader towards the free end of the shaft. The spreader is connected via a transmission rod, to the spring assembly located in the handle (2). This rod is laid in a groove (7). This runs along the shaft up to the handle, and is open to one side. The shaft carries a sliding casing (13) connected to the spring assembly and spreader. Spreader retraction is effected by pulling a radially-projecting flange (14) on the casing. In an alternative design based on the foregoing principles, a rocking handle component is provided for spreader retraction.