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Harvester (forestry)
A harvester is a type of heavy forestry vehicle employed in cut-to-length logging operations for felling, delimbing and bucking trees. A forest harvester is typically employed together with a forwarder that hauls the logs to a roadside landing. History Forest harvesters were mainly developed in Sweden and Finland and today do practically all of the commercial felling in these countries. The first fully mobile timber "harvester", the PIKA model 75, was introduced in 1973Rihko Haarlaa: Organization and technology of wood harvesting in Finland.' Department of Forest Resource Management, University of Helsinki, Finland. 1992. by Finnish systems engineer Sakari Pinomäki and his company PIKA Forest Machines. The first single grip harvester head was introduced in the early 1980s by Swedish company SP Maskiner. Their use has become widespread throughout the rest of Northern Europe, particularly in the harvesting of plantation forests. Before modern harvesters were developed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Harvester
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some reaching several thousand years old. Trees have been in existence for 370 million years. It is estimated that there are some three trillion mature trees in the world. A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plantation
A plantation is an agricultural estate, generally centered on a plantation house, meant for farming that specializes in cash crops, usually mainly planted with a single crop, with perhaps ancillary areas for vegetables for eating and so on. The crops that are grown include cotton, coffee, tea, cocoa, sugar cane, opium, sisal, oil seeds, oil palms, fruits, rubber trees and forest trees. Protectionist policies and natural comparative advantage have sometimes contributed to determining where plantations are located. In modern use the term is usually taken to refer only to large-scale estates, but in earlier periods, before about 1800, it was the usual term for a farm of any size in the southern parts of British North America, with, as Noah Webster noted, "farm" becoming the usual term from about Maryland northwards. It was used in most British colonies, but very rarely in the United Kingdom itself in this sense. There, as also in America, it was used mainly for tree plantati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programmable Logic Controller
A programmable logic controller (PLC) or programmable controller is an industrial computer that has been ruggedized and adapted for the control of manufacturing processes, such as assembly lines, machines, robotic devices, or any activity that requires high reliability, ease of programming, and process fault diagnosis. Dick Morley is considered as the father of PLC as he had invented the first PLC, the Modicon 084, for General Motors in 1968. PLCs can range from small modular devices with tens of inputs and outputs (I/O), in a housing integral with the processor, to large rack-mounted modular devices with thousands of I/O, and which are often networked to other PLC and SCADA systems. They can be designed for many arrangements of digital and analog I/O, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed-up or non-volatile memory. PLCs were first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-stroke Cycle
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of the crankshaft. A four-stroke engine requires four strokes of the piston to complete a power cycle during two crankshaft revolutions. In a two-stroke engine, the end of the combustion stroke and the beginning of the compression stroke happen simultaneously, with the intake and exhaust (or scavenging) functions occurring at the same time. Two-stroke engines often have a high power-to-weight ratio, power being available in a narrow range of rotational speeds called the power band. Two-stroke engines have fewer moving parts than four-stroke engines. History The first commercial two-stroke engine involving cylinder compression is attributed to Scottish engineer Dugald Clerk, who patented his design in 1881. However, unlike most later two-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvester Cutter
Harvester may refer to: Agriculture and forestry * Combine harvester, a machine commonly used to harvest grain crops * Forage harvester, a machine used to harvest forage * Harvester (forestry), a type of heavy vehicle employed in cut-to-length logging of trees * International Harvester, a former agricultural machinery company Information technology * Harvester (web), a tool to download websites * Bioinformatic Harvester, a bioinformatic meta search engine Music * Harvester (band) or Träd, Gräs, och Stenar, a Swedish progressive band * Harvester (American band), an American indie rock band * The Harvesters (band), a Swedish alternative country band Places * Burr Ridge, Illinois or Harvester * Harvester, Missouri, an unincorporated community in St. Charles County Zoology * '' Feniseca tarquinius'' or harvesters, a species of butterflies * ''Miletinae'' or harvesters, a subfamily of butterflies * ''Opiliones'' or harvesters, an order of arachnids superficially similar to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvester Hf
Harvester may refer to: Agriculture and forestry * Combine harvester, a machine commonly used to harvest grain crops * Forage harvester, a machine used to harvest forage * Harvester (forestry), a type of heavy vehicle employed in cut-to-length logging of trees * International Harvester, a former agricultural machinery company Information technology * Harvester (web), a tool to download websites * Bioinformatic Harvester, a bioinformatic meta search engine Music * Harvester (band) or Träd, Gräs, och Stenar, a Swedish progressive band * Harvester (American band), an American indie rock band * The Harvesters (band), a Swedish alternative country band Places * Burr Ridge, Illinois or Harvester * Harvester, Missouri, an unincorporated community in St. Charles County Zoology * '' Feniseca tarquinius'' or harvesters, a species of butterflies * ''Miletinae'' or harvesters, a subfamily of butterflies * ''Opiliones'' or harvesters, an order of arachnids superficially similar to s ... [...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] |
Hydraulic Machinery
Hydraulic machines use liquid fluid power to perform work. Heavy construction vehicles are a common example. In this type of machine, hydraulic fluid is pumped to various hydraulic motors and hydraulic cylinders throughout the machine and becomes pressurized according to the resistance present. The fluid is controlled directly or automatically by control valves and distributed through hoses, tubes, or pipes. Hydraulic systems, like pneumatic systems, are based on Pascal's law which states that any pressure applied to a fluid inside a closed system will transmit that pressure equally everywhere and in all directions. A hydraulic system uses an incompressible liquid as its fluid, rather than a compressible gas. The popularity of hydraulic machinery is due to the very large amount of power that can be transferred through small tubes and flexible hoses, the high power density and a wide array of actuators that can make use of this power, and the huge multiplication of forc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-called compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine ( gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). Diesel engines work by compressing only air, or air plus residual combustion gases from the exhaust (known as exhaust gas recirculation (EGR)). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases the air temperature inside the cylinder to such a high degree that atomised diesel fuel injected into the combustion chamber ignites. With the fuel being injected into the air just before combustion, the dispersion of the fuel i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walking Excavator
A walking excavator or popularly spider excavator is a special type of all-terrain excavator. Like the regular excavator it consists of a boom, stick, bucket and cab on a rotating platform known as the "house". However, its house sits atop an undercarriage consisting of leg or arm-like extensions with or without wheels. All extensions can move in increments, hence the name ''walking excavator''. This is different from an early 20th century dragline excavator where a set of feet plate are alternately lifted and lowered. History Most traditional excavators have tracks or wheels as undercarriage, limiting their usability on steep inclines, uneven terrain or inaccessible positions. In 1966, Edwin Ernst Menzi (1897–1984) and Joseph Kaiser (1928–1993) together invented the walking excavator for work on mountain slopes. Subsequently, Kaiser AG, Schaanwald, Liechtenstein, and Menzi Muck AG, Kriessern, Switzerland, developed excavators separately. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuous Track
Continuous track is a system of vehicle propulsion used in tracked vehicles, running on a continuous band of treads or track plates driven by two or more wheels. The large surface area of the tracks distributes the weight of the vehicle better than steel or rubber tires on an equivalent vehicle, enabling continuous tracked vehicles to traverse soft ground with less likelihood of becoming stuck due to sinking. Modern continuous tracks can be made with soft belts of synthetic rubber, reinforced with steel wires, in the case of lighter agricultural machinery. The more common classical type is a solid chain track made of steel plates (with or without rubber pads), also called caterpillar tread or tank tread, which is preferred for robust and heavy construction vehicles and military vehicles. The prominent treads of the metal plates are both hard-wearing and damage resistant, especially in comparison to rubber tyres. The aggressive treads of the tracks provide good t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheel
A wheel is a circular component that is intended to rotate on an axle bearing. The wheel is one of the key components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, or performing labor in machines. Wheels are also used for other purposes, such as a ship's wheel, steering wheel, potter's wheel, and flywheel. Common examples are found in transport applications. A wheel reduces friction by facilitating motion by rolling together with the use of axles. In order for wheels to rotate, a moment needs to be applied to the wheel about its axis, either by way of gravity or by the application of another external force or torque. Using the wheel, Sumerians invented a device that spins clay as a potter shapes it into the desired object. Terminology The English word '' wheel'' comes from the Old English word , from Proto-Germanic , f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
