Vintage Antique steel in Line Roller Skates

Description

I know very little about these skates.  They came from and estate of an avid collector.  They are about 13" long and have hard rubber covering steel wheels.  The rubber is in very good condition.  The wheel turn freely, one is a little tighter than the other three.  There is a lever that must lock your shoes into place.  I can not find a name or date for these, but they are quite interesting.  I have not seen them on any other sites.