A friend of mine picked a Bivans out of the trash and gave it to me. The next week I picked up its brother off ebay. So I did some research.
Sorry for the poor photos, someone wanted my good camara more than me.
The background is from the patent application.
The patent was applied forin 1950. The small reel has to be taken apart to set the drag. The spool and the handle are not directly conected so when a fish swims toward you and then turns and runs there is no snap when he hits the end of the line only drag.