................ the reel must swivel.
The idea of the chain was apparently so that you could operate the jack under the car without getting down on your hands and knees yourself. It made jacking the up car, "child's play". Check out the attachment (if I have done it correctly). I have seen similar advertisements showing women in fine gowns doing the jacking.....No, not that!
The chain reel is meant to swivel so that the chain is pulled from a suitable angle. Mine does!
Mine doesn't seem to have as long a leg as the one pictured by jimwrench. The cover is stamped "Weed Chain Jack, Made in U.S.A., Pat Feb 1916, Capacity 1 ton" There is also a 5.23.16 patent date cast into the flip over extension on the top