Never seen one, what I am reading they may have been a way to create a real strong ratchet, and they may have been used with t-bars and breaker bars.
I remember sets coming with t-bars and speed wrenches. Does anybody actually use those? I like breaker bars, though I think they are not as common now either. Maybe because of impact wrenches. Breaker bar and cheater have popped comp nuts pretty easy for me.