Yes I guess they really hung onto it.
They weren't the only ones.
I've talked about this before on various threads. Technically, in catalogs and other marketing, Blackhawk called it a "Hinged Offset Handle", Bonney and Plomb called it a "Hinge Handle", Cornwell, New Britain, and Williams preferred "Flex Handle," Sears, Roebuck & Co (Craftsman) used a hybrid variation ("Flex T Handle"), as did Herbrand ("Flexible Offset Handle") and SK ("Flex Head Handle"). There were some notably unique oddballs: Duro-Chrome preferred "Swing Head Handle", Snap-on, as you alluded to, liked "Nut Spinner Handle", and Thorsen got cute with "Linkjoint Handle."
As far as I have been able to determine, the term "Breaker Bar" wasn't used - and that only colloquially, in shops, etc, until the late 1960's. The earliest I can find it turning up as a technical term in any automotive technical literature is 1971 and that was not a catalog but a hot rod magazine, lending credence to the theory that it came off the street.
The reason, I suspect, is because so many other handles (especially rachets, and especially when they got stronger, and with finer teeth) to turn on and off nuts became so much more preferable, and the trusty hinge handle was relegated only to breaking loose stuck nuts. "Get the breaker." "Use the breaker." Until it only made sense for industry to adopt the term their customers were using.
Interesting that Christensen's "Loose Joint" is pretty close to Thorsen's "Linkjoint".
