Still too complicated. Last night while falling asleep it it me. Air over hydraulic. A 100psi air, four inch stroke cylinder of 1.125 bore pushing a second piston of 3.625" dia. using hydraulics, will develop over 1000lb of force and move the 3.625 piston .375".
You piggy back the two cylinders and make the 1.125 piston hollow so it gives a spring room to go during the down stroke. The bottom of the spring rests on the large 3.625 piston. When air pressure is removed the spring forces the 1.125 piston back up and even though it's base rests on the large piston, the large piston will still retract because the small piston is moving 4" versus the .375 of the large one.
You only need one air line, it all sits on top of the head, and can be run with Mach through an air solenoid. Depending what your junk pile has, pretty easily done. |