Some years ago I picked up a 1.5 ton Yale lever chain hoist for the price of a couple of beers. It's the type with the roller chain not the standard link version. After a couple of years gathering dust I went to use it for the first time and I can't get it to release any chain. What am I doing wrong? Is there a secret to operating it or do they have part of a mechanism that gums up with lack of use?. I'll dismantle it and have a look if there are no suggestions.