Timeline of United States inventions (1890–1945) installing driven conveyor belts that could produce a Model T in ninety-three minutes. 1901 Safety razor (disposable) A safety razor protects the skin from all but the edge of the blade while shaving skin. King Camp Gillette, a traveling hardware salesman of Fond du Lac, Wisconsin invented the double-edged, disposable safety razor attached to a re-usable razor handle. Beforehand, dull razors were taken to barbers for sharpening. With Gillette's double-edged and disposable blades, a uniform shave on a man's face could be achieved with a fresh blade and disposed after it was used. Gillette applied for a patent in 1901.
Safety razor become locked into buying their proprietary cartridges, for as long as the manufacturer continues to make them. Subsequent to introducing the higher-priced Mach3 in 1998, Gillette's blade sales realized a 50% increase, and profits increased in an otherwise mature market. The marketing of increasing numbers of blades in a cartridge has been parodied since the 1970s. The debut episode of "Saturday Night Live" in 1975 included a parody advertisement for the Triple Trac Razor, shortly after the first two-blade cartridge for men's razors was advertised. "Mad" magazine announced the "Trac 76", arranged as a chain of cartridges with a handle