Atrip hammer, also known as atilt hammer orhelve hammer, is a massive poweredhammer. Traditional uses of trip hammers include pounding,decorticating and polishing of grain inagriculture. Inmining, trip hammers were used for crushing metalores into small pieces, although astamp mill was more usual for this. Infinery forges they were used for drawing outblooms made fromwrought iron into more workablebar iron. They were also used for fabricating various articles ofwrought iron,latten (an early form ofbrass),steel and other metals.
One or more trip hammers were set up in aforge, also known variously as ahammer mill, hammer forge or hammer works. The hammers were usually raised by acam and then released to fall under the force ofgravity. Historically, trip hammers were often poweredhydraulically by awater wheel.
Trip hammers are known to have been used inImperial China since theWestern Han dynasty. They also existed in the contemporaryGreco-Roman world, with more evidence of their use inmedieval Europe during the 12th century. During theIndustrial Revolution the trip hammer fell out of favor and was replaced with thepower hammer. Often multiple hammers were powered via a set ofline shafts, pulleys and belts from a centrally located power supply.
In ancient China, the trip hammer evolved out of the use of themortar and pestle, which in turn gave rise to the treadle-operated tilt-hammer (Chinese: 碓Pinyin:dui;Wade-Giles:tui).[1] 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.[2] This device enabled the labor of pounding, often in the decorticating and polishing of grain, and avoided manual pounding with hand and arm.
Although Chinese historians assert that its origins may span as far back as theZhou dynasty (1050 BC–221 BC), the British sinologistJoseph Needham regards the earliest texts to describe the device are theJijiupian dictionary of 40 BC,Yang Xiong'sFangyan of 15 BC, as well as the "best statement" theXin Lun written byHuan Tan about 20 AD (during the usurpation ofWang Mang).[3] The latter book states that the legendaryFu 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 Chinesemetallurgy, seeDu Shi):
Fu Hsi invented the pestle and mortar, which is so useful, and later on it was cleverly improved in such a way that the whole weight of the body could be used for treading on the tilt-hammer (tui), thus increasing the efficiency ten times. Afterwards the power of animals—donkeys, mules, oxen, and horses—was applied by means of machinery, and water-power too used for pounding, so that the benefit was increased a hundredfold.[4]
However, this passage as well as other early references from theHan era may rather refer to a water lever, not a trip hammer.[5][6] Later research, pointing to two contemporary Han era funeral wares depicting hydraulic hammers, proved that vertical waterwheels were used to power batteries of trip hammers during the Han dynasty.[7]
With his description, it is seen that the out-of-date Chinese term for pestle and mortar (dui, tui) would soon be replaced with the Chinese term for the water-powered trip-hammer (Chinese:水碓; pinyin:shuǐ duì; Wade–Giles:shui tui.[2] TheHan dynasty scholar and poetMa Rong (79–166 AD) mentioned in one of his poems of hammers 'pounding in the water-echoing caves'.[4] As described in theHou Han Shu, in 129 AD the officialYu Xu gave a report toEmperor Shun of Han that trip hammers were being exported from Han China to the WesternQiang people by way of canals through theQilian Mountains.[4] In hisRou Xing Lun, the government officialKong Rong (153–208 AD) remarked that the invention of the trip hammer was an excellent example of a product created by intelligent men during his own age (comparing the relative achievements of the sages of old).[4] During the 3rd century AD, the high government official and engineerDu Yu established the use of combined trip hammer batteries (lian zhi dui), which employed several shafts that were arranged to work off one large waterwheel.[8] In Chinese texts of the 4th century, there are written accounts of men possessing and operating hundreds of trip hammer machines, such as the venerable mathematician Wang Rong (died 306 AD), Deng Yu (died 326 AD), and Shi Chong (died 300 AD), responsible for the operation of hundreds of trip hammers in over thirty governmental districts throughout China.[9] There are numerous references to trip hammers during theTang dynasty (618–907 AD) andSong dynasty (960–1279), and there areMing dynasty (1368–1644) references that report the use of trip hammers inpapermills ofFujian Province.[10]
Although Chinese trip hammers in China were sometimes powered by the more efficient vertical-set waterwheel, the Chinese often employed the horizontal-set waterwheel in operating trip hammers, along with recumbent hammers.[11] The recumbent hammer was found in Chinese illustrations by 1313 AD, with the publishing ofWang Zhen'sNong Shu book on ancient and contemporary (medieval) metallurgy in China.[12] There were also illustrations of trip hammers in an encyclopedia of 1637, written bySong Yingxing (1587–1666).[13]
The Chinese use of the cam remained confined to the horizontal type and was limited to a "small variety of machines" that included only rice hulling and much later mica-pounders, paper mills and saw mills, while fulling stocks, ore stamps or forge hammers were unknown.[6]
The main components for water-powered trip hammers –water wheels,cams, and hammers – were known in theHellenistic world.[15] Early cams are in evidence in water-poweredautomata from the 3rd century BC.[16][17] According to M.J.T. Lewis, aflute player whose mechanism was described by the PersianBanū Mūsā brothers in the 9th century AD and can be "reasonably" attributed toApollonius of Perge, functions on the principle of water-powered trip hammers.[18]
TheRoman scholarPliny (Natural History XVIII, 23.97) indicates that water-driven pestles had become fairly widespread inItaly by the first century AD:
The greater part of Italy uses an unshod pestle and also wheels which water turns as it flows past, and a trip-hammer [mola]".
While some scholars have viewed this passage to mean a watermill,[19] later scholarship argued thatmola must refer to water-powered trip hammers which were used for the pounding and hulling ofgrain.[20][16] Their mechanical character is also suggested by an earlier reference ofLucius Pomponius (fl. 100–85 BC) to afuller's mill, a type of mill that has been operated at all times with falling stocks.[21][22] However, it has been pointed out that the translation of Pomponius' fragmentary text could be faulty, and relies on translatingmola, which is often thought to mean either a mill or millstone, to instead refer to a water powered trip hammer.[23] Grain-pounders with pestles, as well as ordinarywatermills, are attested as late as the middle of the 5th century AD in amonastery founded byRomanus of Condat in the remoteJura region, indicating that the knowledge of trip hammers continued into the earlyMiddle Ages.[16]
At the Italian site ofSaepinum excavators have recently unearthed alate antique water mill that may have employed trip hammers fortanning, the earliest evidence of its kind in aclassical context.[24][25]
The widest application of trip hammers seems to have occurred in Roman mining, whereore from deep veins was first crushed into small pieces for further processing.[26] Here, the regularity and spacing of large indentations on stoneanvils indicate the use of cam-operated ore stamps, much like the devices of latermedieval mining.[26][14] Such mechanically deformed anvils have been found at numerous Roman silver and gold mining sites inWestern Europe, including atDolaucothi (Wales), and on theIberian Peninsula,[26][14][27][28] where the datable examples are from the 1st and 2nd century AD.[29] At Dolaucothi, these trip-hammers were hydraulic-driven and possibly also at other Roman mining sites, where the large-scale use of thehushing and ground sluicing technique meant that large amounts of water were directly available for powering the machines.[26][30] However, none of the Spanish and Portuguese anvils can be convincingly associated with mill sites, though most mines had water sources and leat systems which could easily be harnessed.[14] Likewise, the dating of the Pumsaint stone to the Roman era did not address that the stone could have been moved, and relies on a series of interlinked probabilities which would jeopardize the conclusion of a Roman dating should any of them unravel.[14]
Water-powered and mechanised trip hammers reappeared inmedieval Europe by the 12th century. Their use was described in medieval written sources ofStyria (in modern-day Austria), written in 1135 and another in 1175 AD.[31] Medieval French sources of the years 1116 and 1249 both record the use of mechanised trip hammers used in the forging ofwrought iron.[31] Medieval European trip hammers by the 15th century were most often in the shape of the vertical pestle stamp-mill, although they employed more frequent use of the vertical waterwheel than earlier Chinese versions (which often used the horizontal waterwheel).[10] The well-knownRenaissance artist and inventorLeonardo da Vinci often sketched trip hammers for use in forges and even file-cutting machinery, those of the vertical pestle stamp-mill type.[12] The oldest depicted European illustration of a forge-hammer is perhaps theA Description of the Northern Peoples ofOlaus Magnus, dated to 1565 AD.[12] In this woodcut image, there is the scene of three martinets and a waterwheel working wood and leather bellows of theOsmund Bloomery furnace.[12] The recumbent hammer was first depicted in European artwork in an illustration bySandrart andZonca (dated 1621 AD).[12]
A trip hammer has the head mounted at the end of a recumbenthelve, hence the alternative name of helve hammer. The choice of which type was used in a particular context may have depended on the strain that its operation imposed on the helve. This was normally of wood, mounted in a cast-iron ring (called the hurst) where it pivoted. However, in the 19th century the heaviest helves were sometimes a single casting, incorporating the hurst.
Thetilt hammer ortail helve hammer has a pivot at the centre of the helve on which it is mounted, and is lifted by pushing the opposite end to the head downwards. In practice, the head on such hammers seems to have been limited to one hundredweight (about 50 kg), but a very rapid stroke rate was possible. This made it suitable for drawing iron down to small sizes suitable for the cutlery trades. There were therefore many such forges known as 'tilts' aroundSheffield. They were also used inbrass battery works for making brass (or copper) pots and pans. In battery works (at least) it was possible for one power source to operate several hammers. In Germany, tilt hammers of up to 300 kg were used in hammer mills to forge iron. Surviving, working hammers, powered by water wheels, may be seen, for example, at theFrohnauer Hammer in theOre Mountains.
Thebelly helve hammer was the kind normally found in afinery forge, used for makingpig iron into forgeable bar iron. This was lifted by cams striking the helve between the pivot and the head. The head usually weighed quarter of a ton. This was probably the case because the strain on a wooden helve would have been too great if the head were heavier.
Thenose helve hammer seems to have been unusual until the late 18th or early 19th century. This was lifted beyond the head. Surviving nose helves[32] and those in pictures[33] appear to be of cast iron.
The steam-powereddrop hammer replaced the trip hammer (at least for the largest forgings).James Nasmyth invented it in 1839 andpatented in 1842. However, by then forging had become less important for the iron industry, following the improvements to therolling mill that went along with the adoption ofpuddling from the end of the 18th century. Nevertheless, hammers continued to be needed forshingling.
{{cite book}}:|periodical= ignored (help)
