Safety razor the rectangular dimensions shared by the wedge, standard single-edge, and double-edge blades. The injector, itself, was also the first device intended to reduce the risk of injury from handling blades. The Gillette blade dispenser released in 1947 had the same purpose. The narrow injector blade, as well as the form of the injector razor, also strongly influenced the corresponding details of the subsequently developed cartridge razors. Both injector blades and injector safety razors are still available on the market, from antique stock as well as modern manufacture. The injector blades have also inspired a variety of specialised blades for professional
Safety razor professional) and remained a barrier to the ubiquitous adopting of the "be your own barber" ideal. The first safety razors used a single-edge blade that was essentially a 4 cm long segment of a straight razor. A flat blade that could be used alternately with this "wedge" was first illustrated in a patent issued in 1878, serving as a close prototype for the single-edge blade in its present form. New single-edge razors were developed and used side-by-side with double-edge razors for decades. The largest manufacturers were the American Safety Razor Company with its "Ever-Ready" series, and the Gem Cutlery Company