B21J7/00—Hammers; Forging machines with hammers or die jaws acting by impact
B21J7/02—Special design or construction
B21J7/10—Special design or construction with both drive and hammer connected to a fulcrumed lever, e.g. tail hammers
B21J7/12—Special design or construction with both drive and hammer connected to a fulcrumed lever, e.g. tail hammers the lever being a spring, i.e. spring hammers