Fig. 3044.
[Fig. 3044] represents a Standish’s foot-power hammer, in which the hammer and the anvil are provided with dovetail seats for receiving dies, swages, &c. The force of the blow is regulated by the height to which the hammer is raised, which may be adjusted by the nuts beneath the spiral springs. The handle on the hammer is for pulling the hammer down by hand when adjusting the lower die fair with the upper one.
What are known as power hammers are those driven by belt and pulley; while those known as trip hammers have their helve lifted through the medium of revolving lugs or cams. Steam hammers are those in which the hammer is lifted by a piston in a steam cylinder; while in hydraulic hammers, the hammer is moved by water pressure.
Fig. 3045.
[Fig. 3045] represents a Justice’s power hammer, in which the hammer is guided in a slideway and is operated by leather straps attached to the ends of a spring, at the crown of which is attached a connecting rod driven by a crank disk. The stroke is altered by means of placing the crank pin in the required position in the slot in the crank disk. By means of gibs the hammer may be set to match the dies. The pulley is provided with a friction clutch operated by the treadle, shown.
Fig. 3046.