When I was a young teenager & working around my dad's garage one of those was a common tool for us to use when pulling a rear drum.. First u removed the nut on the side u wanted to pull the drum from, then u screws the "puller on tight" so as to bottom out, Then u jacked the opposite side to just get the tire free from the floor, Then we would hit that puller with a sledge hammer, the bigger the better, sometimes 2 or 3 times would be enough.. Then lower the jack, remove the puller and then the drum.. But if it was difficult to remove the drum backing off the brake shoes would usually be enough to free the drum..
Remember I,m talking about in the late 30"s, early 4o's. Now today I use a 3 legged puller.
