British patent 3557
A further improvement relates to revolver pistols such as are described in Specification No. 3622, A.D. 1868. The central rod Q, Fig. 4, which operates the extractor when the barrel is raised about its hinge, is actuated by a lever R instead of by a rack and pinion. If the barrel is arranged to the slide instead of to turn on a hinge, the rod Q may have a rack formed on it to gear with a pinion on the barrel.