A Goldbeating Machine with an Automatic Hammer
Endless screws, cams and arrest devices drive a hammer that beats gold on an anvil
The sheet works out a goldbeater's machine (battiloro) in which a powered hammer strikes gold on an anvil, with two weights (200 and 500) shown at the main mechanism. It is to be arranged so that the instant the hammer lifts, the gold shifts across the anvil, and an endless screw increases the hammer from 4 up to 8 blows per turn as the leaf widens. Surrounding details show counterweighted arrest devices (good in iron or bronze), a threaded and replaceable ring n, pivoted shaft-ends, and a cylinder of interchangeable "truncated screws" a b c d m f.
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Shifting the gold the moment the hammer lifts
The beating rod itself must not change its place. Arrange it so that, as soon as the hammer lifts from the gold, the gold immediately shifts across the anvil.
Eight blows per turn set by an endless screw
The hammer gives 8 blows for every turn of the rocca, its guide. If the gold is narrower at the start of beating than at the end, change the endless screw each time: a half-turn gives 4 blows, the next change 5, then 6, 7, 8, and the width is finished.
Counterweighted arrest devices (b, a)
An arrest device with a counterweight, lettered b a and M: when b touches a, b falls into the notch. A second arrest device at the upper left is noted as good made in iron or bronze.
Interchangeable truncated screws (a b c d m f)
Let all the screws be movable, that is a b c d m f. Use truncated screws of various lengths according to the widening of the gold, and make each one, by itself, fixable with two small screws at the place m n.
Replaceable threaded ring and pivoted shaft-ends
The male of the ring n must be threaded so it can be changed as it wears out. The poles of the rotating shaft at each end must be pivoted like the detail a.