Hello Matei, I can just do a few pictures of the hammer, is one of my older leaf is a little less strong than those autocompressori but they told me that they are more accurate in determining the shots and their construction with mechanical parts are less likely to broken ... the new models have a workaround but more or less have the same effect.
A motor at 380 volts. that spins a large pulley and inside has a clutch, more prizes the more the clutch pedal moves away from the pulley and the bat drops faster when soft has a double system to stop the travel, the leaf springs have only the task to amortize the strongest blows that's all .... I wanted to costruirmene one hand, but on balance should not waste time, my used cost me about 2000 euros about $ 2500, if you consider that weighs about 900 kg. I spent a lot of money just for the material, here in Italy they are also cheaper, mine is used very little hammers has provided new again