Maybe,just maybe,Jerry and Joe were sitting one day and one said " I like the name of that razor.I reckon it would be a great name for a comic superhero".Original patent 1913 and originally known as the Finney, after William C Finney who patented it.Patent sold in 1930. Apparently the Superman name predates the superhero but I don't know when these were actually made. Lots of information here; http://theoriginalsafety2.com/thread/1529/superman
I will post in SOTD when I've given it a try, looking forward to that.