Vintage Perpetual Corkscrew.
An open frame perpetual corkscrew with double cross over thread on the shaft. This is a very effective design of cork screw patented by Ernst Demmler in 1884. By continually turning the handle the worm is screwed into the cork, which is then lifted out of the bottle all with the same turning motion. A great corkscrew in working order with a turned wooden T-handle.