Tilt hammer

A trip hammer, also known as a helve hammer, is a massive powered hammer used in:

One or more trip hammers were set up in a workshop known variously as a hammer mill, hammer forge or hammer works. The hammers were usually raised by a cam and then released to fall under the force of gravity. Historically, trip hammers were often powered by a water wheel, and are known to have been used in China as long ago as 40 BC or maybe even as far back as the Zhou Dynasty (1050 BC–221 BC) and in medieval Europe by the 12th century. During the Industrial Revolution the trip hammer fell out of favor and was replaced with the power hammer. Often multiple hammers were powered via a set of line shafts, pulleys and belts from a centrally located power supply.

In ancient China, the trip hammer evolved out of the use of the mortar and pestle, which in turn gave rise to the treadle-operated tilt-hammer (Chinese: 碓 Pinyin: dui; Wade-Giles: tui). The latter was a simple device employing a lever and fulcrum (operated by pressure applied by the weight of one's foot to one end), which featured a series of catches or lugs on the main revolving shaft as well. This device enabled the labor of pounding, often in the decorticating and polishing of grain, and avoided manual use of pounding with hand and arm. Although historians assert that its origins may span as far back as the Zhou Dynasty (1050 BC–221 BC), the earliest texts to describe the device are the Jijiupian dictionary of 40 BC, Yang Xiong's text known as the Fangyan of 15 BC, as well as the Xin Lun written by Huan Tan about 20 AD (during the usurpation of Wang Mang). The latter book states that the legendary mythological king known as Fu Xi was the one responsible for the pestle and mortar (which evolved into the tilt-hammer and then trip hammer device). Although the author speaks of the mythological Fu Xi, a passage of his writing gives hint that the waterwheel and trip-hammer were in widespread use by the 1st century AD in China (for water-powered Chinese metallurgy, see Du Shi):

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