Fiamme rims:
The principle of using a tubular cross section, with eyelets (a.k.a. ferrules?) joining the inside and outside of the rim, dates back to the 1930's. This permits the load from spoke tension to be shared by both sides of the rim, permitting lighter materials than if just one side of the rim carried all of the load.
Fiamme was the first to license the patent for this innovation.
For some context, I'm attaching a page from the mid-70's Cyclo-Pedia catalog. It shows the use of the eyelets by all of the manufacturers listed, although only on the tubular rims. It wasn't until a bit later that clincher rims used a construction that mimicked some of the shape of a tubular, and then used the same sort of eyelets.
Steve in Peoria