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Trencher (machine)
A trencher is a piece of construction equipment used to dig trenches, especially for laying pipes or electrical cables, for installing drainage, or in preparation for trench warfare. Trenchers may range in size from walk-behind models, to attachments for a skid loader or tractor, to very heavy tracked heavy equipment. Types Trenchers come in different sizes and may use different digging implements, depending on the required width and depth of the trench and the hardness of the surface to be cut. Wheel trencher A wheel trencher or rockwheel is composed of a toothed metal wheel. It is cheaper to operate and maintain than chain-type trenchers. It can work in hard or soft soils, either homogeneous (compact rocks, silts, sands) or heterogeneous (split or broken rock, alluvia, moraines). This is particularly true because a cutting wheel works by clearing the soil as a bucket-wheel does, rather than like a rasp (chain trencher). Consequently, it will be less sensitive to the presen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Marais Wheel Trencher In Sout Africa
A, or a, is the first letter and the first vowel of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''a'' (pronounced ), plural ''aes''. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English grammar, " a", and its variant " an", are indefinite articles. History The earliest certain ancestor of "A" is aleph (also written 'aleph), the first letter of the Phoenician alphabet, which consisted entirely of consonants (for that reason, it is also called an abjad to distinguish it f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant typically need an additional 11% chromium. Because of its high tensile strength and low cost, steel is used in buildings, infrastructure, tools, ships, trains, cars, machines, electrical appliances, weapons, and rockets. Iron is the base metal of steel. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic. The interaction of the allotropes of iron with the alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed. In steel, small amounts of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geotextile
Geotextiles are permeable fabrics which, when used in association with soil, have the ability to separate, filter, reinforce, protect, or drain. Typically made from polypropylene or polyester, geotextile fabrics come in two basic forms: woven (resembling mail bag sacking) and nonwoven (resembling felt). Geotextile composites have been introduced and products such as geogrids and meshes have been developed. Geotextiles are durable and are able to soften a fall. Overall, these materials are referred to as geosynthetics and each configuration—geonets, geosynthetic clay liners, geogrids, geotextile tubes, and others—can yield benefits in geotechnical and environmental engineering design. History Geotextiles were originally intended to be a substitute for granular soil filters. The original, and still sometimes used, term for geotextiles is ''filter fabrics''. Work originally began in the 1950s with R.J. Barrett using geotextiles behind precast concrete seawalls, under precast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lawn Mower
A lawn mower (also known as a mower, grass cutter or lawnmower) is a device utilizing one or more revolving blades (or a reel) to cut a grass surface to an even height. The height of the cut grass may be fixed by the design of the mower, but generally is adjustable by the operator, typically by a single master lever, or by a lever or nut and bolt on each of the machine's wheels. The blades may be powered by manual force, with wheels mechanically connected to the cutting blades so that when the mower is pushed forward, the blades spin or the machine may have a battery-powered or plug-in electric motor. The most common self-contained power source for lawn mowers is a small (typically one cylinder) internal combustion engine. Smaller mowers often lack any form of propulsion, requiring human power to move over a surface; "walk-behind" mowers are self-propelled, requiring a human only to walk behind and guide them. Larger lawn mowers are usually either self-propelled "walk-behind" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FTTx
Fiber to the ''x'' (FTTX; also spelled "fibre") or fiber in the loop is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications. As fiber optic cables are able to carry much more data than copper cables, especially over long distances, copper telephone networks built in the 20th century are being replaced by fiber. FTTX is a generalization for several configurations of fiber deployment, arranged into two groups: FTTP/FTTH/FTTB (Fiber laid all the way to the premises/home/building) and FTTC/N (fiber laid to the cabinet/node, with copper wires completing the connection). Residential areas already served by balanced pair distribution plant call for a trade-off between cost and capacity. The closer the fiber head, the higher the cost of construction and the higher the channel capacity. In places not served by metallic facilities, little cost is saved by not running fiber to the h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Breaker
A breaker is a powerful percussion hammer fitted to an excavator for demolishing hard (rock or concrete) structures. It is powered by an auxiliary hydraulic system from the excavator, which is fitted with a foot-operated valve for this purpose. Additionally, demolition crews employ the hoe ram for jobs too large for jackhammering or areas where blasting is not possible due to safety or environmental issues. Breakers are often referred to as "hammers", "peckers", "hoe rams" or "hoe rammers". These terms are popular and commonly used amongst construction/demolition workers. The first hydraulic breaker, Hydraulikhammer HM 400, was invented in 1967 by German company Krupp (today German company Atlas Copco) in Essen. See also * Excavator Excavators are heavy construction equipment consisting of a boom, dipper (or stick), bucket and cab on a rotating platform known as the "house". The house sits atop an undercarriage with tracks or wheels. They are a natural progression fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excavator
Excavators are heavy construction equipment consisting of a boom, dipper (or stick), bucket and cab on a rotating platform known as the "house". The house sits atop an undercarriage with tracks or wheels. They are a natural progression from the steam shovels and often mistakenly called power shovels. All movement and functions of a hydraulic excavator are accomplished through the use of hydraulic fluid, with hydraulic cylinders and hydraulic motors. Due to the linear actuation of hydraulic cylinders, their mode of operation is fundamentally different from cable-operated excavators which use winches and steel ropes to accomplish the movements. Terminology Excavators are also called diggers, JCBs (a proprietary name, in an example of a generic trademark), mechanical shovels, or 360-degree excavators (sometimes abbreviated simply to "360"). Tracked excavators are sometimes called "trackhoes" by analogy to the backhoe. In the UK and Ireland, wheeled excavators are somet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chainsaw
A chainsaw (or chain saw) is a portable gasoline-, electric-, or battery-powered saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar. It is used in activities such as tree felling, limbing, bucking, pruning, cutting firebreaks in wildland fire suppression, and harvesting of firewood. Chainsaws with specially designed bar-and-chain combinations have been developed as tools for use in chainsaw art and chainsaw mills. Specialized chainsaws are used for cutting concrete during construction developments. Chainsaws are sometimes used for cutting ice; for example, ice sculpture and winter swimming in Finland. History In surgery The origin of chain saws in surgery is debated. A "flexible saw", consisting of a fine serrated link chain held between two wooden handles, was pioneered in the late 18th century (c. 1783–1785) by two Scottish doctors, John Aitken and James Jeffray, for symphysiotomy and excision of diseased bone, respectively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ditch Witch HT330 Track Trencher Stationary
A ditch is a small to moderate divot created to channel water. A ditch can be used for drainage, to drain water from low-lying areas, alongside roadways or fields, or to channel water from a more distant source for plant irrigation. Ditches are commonly seen around farmland, especially in areas that have required drainage, such as The Fens in eastern England and much of the Netherlands. Roadside ditches may provide a hazard to motorists and cyclists, whose vehicles may crash into them and get damaged, flipped over, or stuck and cause major injury, especially in poor weather conditions and rural areas. Etymology In Anglo-Saxon, the word ''dïc'' already existed and was pronounced "deek" in northern England and "deetch" in the south. The origins of the word lie in digging a trench and forming the upcast soil into a bank alongside it. This practice has meant that the name ''dïc'' was given to either the excavation or the bank, and evolved to both the words "dike"/"dyke" and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cemented Carbide
Cemented carbides are a class of hard materials used extensively for cutting tools, as well as in other industrial applications. It consists of fine particles of carbide cemented into a composite by a binder metal. Cemented carbides commonly use tungsten carbide (WC), titanium carbide (TiC), or tantalum carbide (TaC) as the aggregate. Mentions of "carbide" or "tungsten carbide" in industrial contexts usually refer to these cemented composites. Most of the time, carbide cutters will leave a better surface finish on a part and allow for faster machining than high-speed steel or other tool steels. Carbide tools can withstand higher temperatures at the cutter-workpiece interface than standard high-speed steel tools (which is a principal reason enabling the faster machining). Carbide is usually superior for the cutting of tough materials such as carbon steel or stainless steel, as well as in situations where other cutting tools would wear away faster, such as high-quantity prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Speed Steel
High-speed steel (HSS or HS) is a subset of tool steels, commonly used as cutting tool material. It is often used in power-saw blades and drill bits. It is superior to the older high-carbon steel tools used extensively through the 1940s in that it can withstand higher temperatures without losing its temper (hardness). This property allows HSS to cut faster than high carbon steel, hence the name ''high-speed steel''. At room temperature, in their generally recommended heat treatment, HSS grades generally display high hardness (above Rockwell hardness 60) and abrasion resistance (generally linked to tungsten and vanadium content often used in HSS) compared with common carbon and tool steels. History In 1868 English metallurgist Robert Forester Mushet developed Mushet steel, considered the forerunner of modern high-speed steels. It consisted of 2% carbon, 2.5% manganese, and 7% tungsten. The major advantage of this steel was that it hardened when air cooled from a temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tool Steel
Tool steel is any of various carbon steels and alloy steels that are particularly well-suited to be made into tools and tooling, including cutting tools, dies, hand tools, knives, and others. Their suitability comes from their distinctive hardness, resistance to abrasion and deformation, and their ability to hold a cutting edge at elevated temperatures. As a result, tool steels are suited for use in the shaping of other materials, as for example in cutting, machining, stamping, or forging. With a carbon content between 0.5% and 1.5%, tool steels are manufactured under carefully controlled conditions to produce the required quality. The presence of carbides in their matrix plays the dominant role in the qualities of tool steel. The four major alloying elements that form carbides in tool steel are: tungsten, chromium, vanadium and molybdenum. The rate of dissolution of the different carbides into the austenite form of the iron determines the high-temperature performance of st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
