Or, perhaps more correct, a double double edged cartridge razor. Which sounds both weird and pointless, but stay with me here.

Invented by Sergio Somonetti, and assigned to Warner Lambert Co LLC, the double edged cartridge razor strikes me as a typical transitional device. It looked like a traditional safety razor, yet used the recent idea of cartridges. And since Sergio suggested using two blades in each cartridge, it became a double double edged cartridge razor.¹

A guard bar for a safety razor don’t sound like something you could file a patent for in 1971. After all, all safety razors – well, almost all – have had a guard since the original Kampfe. You could argue that the concept of a guard was inherent to the idea of a safety razor, from Jean Jacques Perret and until today. So… since Jan Dawidowicz did in fact get a patent for a guard bar for safety razors in 1973, it must have been a special guard bar. Special and non-obvious. And Even in hindsight I would say the later is correct.

Most patents seems to revolve around solving a problem, imaginary or otherwise.¹ So let us see what problem Jan was wanting to solve.