I cherish my oldest tools, so here's another. This compressor is operated by the lever, opposite the spring retaining arms. It was given to me by a retiring machinist in the early ‘70’s, so not new! He probably used it for +40 years in the engine rebuilding shop where he worked. He was well known for rebuilding FORD Model T and A engines. I used to by parts there, when I was a kid and pestered the guys endlessly. I borrowed it so often, he gave it to me on his last day. Makes me smile, whenever I use it. It’s probably +80 years old.
As you crank the rotating lever, it drives down the arm that pushes on the valve “hat’. The arm is serrated and is locked in place by the small, sprung lever (a bit like the mechanism on a come-along winch). To release, you apply some extra pressure and lift off the locking lever..... The gear teeth are very worn, so it’s a bit dodgy.
