Rock Crusher History
Apr 16, history tells us, it was in , the first us patent was issued on a rock crushing machine.it covered a device which, in a crude way, incorporated the drop hammer principle later used in the famous stamp mill, whose history is so intimately linked with that of the golden age of mining.in , another patent was issued, which comprised a wooden box containing a cylindrical drum apparently of.Apr 22, mighty mill portable mini rock crusher. sample gold ore fast! what features make this crusher so unique?. this is the only mini crusher on the market with this feature! mighty mill! sampling, and small runs.