|
Axe (tool)
An axe ( sometimes ax in American English; American and British English spelling differences#Miscellaneous spelling differences, see spelling differences) is an implement that has been used for Millennium, millennia to Wood carving, shape, Wood splitting, split and Woodchopping, cut wood, to harvest Lumber, timber, as a battle axe, weapon, and as a ceremony, ceremonial or Heraldry, heraldic symbol. The axe has many forms and specialised uses but generally consists of an axe head with a Handle (grip), handle, or ''helve''. Before the modern axe, the Stone Age, stone-age hand axe without a handle was used from 1.5 million years Before Present, BP. Hafted axes (those with a handle) date only from 6000 BC. The earliest examples of handled axes have heads of rock (geology), stone with some form of wooden handle attached (hafting, hafted) in a method to suit the available materials and use. Axes made of copper, bronze, iron and steel appeared as these technologies developed. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felling Axe
Felling is the process of cutting down trees,"Feller" def. 2. and "Felling", def. 1. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) © Oxford University Press 2009 an element of the task of logging. The person cutting the trees is a ''feller''. A feller buncher is a machine capable of felling a single large tree or grouping and felling several small ones simultaneously. Methods Hand felling In hand felling, an axe, saw, or chainsaw is used to fell a tree, followed up by limbing and bucking in traditional applications. In the modern commercial logging industry, felling is typically followed by limbing and skidding. Feller buncher A feller-buncher is a motorized vehicle with an attachment which rapidly cuts and gathers several trees in the process of felling them. In cut-to-length logging a harvester performs the tasks of a feller-buncher, additionally doing the delimbing and bucking. When harvesting wood from a felled tree, the recommended methods should ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand Axe
A hand axe (or handaxe or Acheulean hand axe) is a prehistoric stone tool with two faces that is the longest-used tool in human history, yet there is no academic consensus on what they were used for. It is made from stone, usually flint or chert that has been "reduced" and shaped from a larger piece by knapping, or hitting against another stone. They are characteristic of the lower Acheulean and middle Palaeolithic (Mousterian) periods, roughly 1.6 million years ago to about 100,000 years ago, and used by ''Homo erectus'' and other early humans, but rarely by ''Homo sapiens''. Their technical name (biface) comes from the fact that the archetypical model is a generally bifacial (with two wide sides or faces) and almond-shaped (amygdaloidal) lithic flake. Hand axes tend to be symmetrical along their longitudinal axis and formed by pressure or percussion. The most common hand axes have a pointed end and rounded base, which gives them their characteristic almond shape, and both f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadaxe
A broadaxe is a large (broad)-headed axe. There are two categories of cutting edge on broadaxes, both are used for shaping logs by hewing. On one type, one side is flat, and the other side beveled, a basilled edge, also called a side axe, single bevel, or chisle-edged axe. On the other type, both sides are beveled, sometimes called a double bevel axe, which produces a scalloped cut. On the basilled broadaxe the handle may curve away from the flat side to allow an optimal stance by the hewer in relation to the hewn surface. The flat blade is to make the surface flat but can only be worked from one direction and is right-handed or left-handed. The double bevel axe has a straight handle and can be swung with either side against the wood. A double beveled broad axe can be used for chopping or notching as well as hewing. When used for hewing, notches are chopped in the side of the log down to a marked line, a process called scoring. The pieces of wood between these notches are removed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felling
Felling is the process of cutting down trees,"Feller" def. 2. and "Felling", def. 1. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) © Oxford University Press 2009 an element of the task of logging. The person cutting the trees is a ''feller''. A feller buncher is a machine capable of felling a single large tree or grouping and felling several small ones simultaneously. Methods Hand felling In hand felling, an axe, saw, or chainsaw is used to fell a tree, followed up by limbing and bucking in traditional applications. In the modern commercial logging industry, felling is typically followed by limbing and skidding. Feller buncher A feller-buncher is a motorized vehicle with an attachment which rapidly cuts and gathers several trees in the process of felling them. In cut-to-length logging a harvester performs the tasks of a feller-buncher, additionally doing the delimbing and bucking. When harvesting wood from a felled tree, the recommended methods should ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lever
A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or ''fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is divided into three types. Also, leverage is mechanical advantage gained in a system. It is one of the six simple machines identified by Renaissance scientists. A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the mechanical advantage of the lever. As such, the lever is a mechanical advantage device, trading off force against movement. Etymology The word "lever" entered English around 1300 from Old French, in which the word was ''levier''. This sprang from the stem of the verb ''lever'', meaning "to raise". The verb, in turn, goes back to the Latin ''levare'', itself from the adjective ''levis'', meaning "light" (as in "not heavy"). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclined Plane
An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with one end higher than the other, used as an aid for raising or lowering a load. The inclined plane is one of the six classical simple machines defined by Renaissance scientists. Inclined planes are used to move heavy loads over vertical obstacles. Examples vary from a ramp used to load goods into a truck, to a person walking up a pedestrian ramp, to an automobile or railroad train climbing a grade. Moving an object up an inclined plane requires less force than lifting it straight up, at a cost of an increase in the distance moved. The mechanical advantage of an inclined plane, the factor by which the force is reduced, is equal to the ratio of the length of the sloped surface to the height it spans. Owing to conservation of energy, the same amount of mechanical energy (work) is required to lift a given object by a given vertical distance, disregarding losses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wedge (mechanical Device)
A wedge is a triangular shaped tool, and is a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converting a force applied to its blunt end into forces perpendicular (normal) to its inclined surfaces. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width..''McGraw-Hill Concise Encyclopedia of Science & Technology'', Third Ed., Sybil P. Parker, ed., McGraw-Hill, Inc., 1992, p. 2041. Although a short wedge with a wide angle may do a job faster, it requires more force than a long wedge with a narrow angle. The force is applied on a flat, broad surface. This energy is transported to the pointy, sharp end of the wedge, hence the force is transported. The wedge simply transports energy in the form of friction and collects it to the pointy end, consequently breaking the item. History Wedges have exi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Machine
A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. Usually the term refers to the six classical simple machines that were defined by Renaissance scientists: * Lever * Wheel and axle * Pulley * Inclined plane * Wedge * Screw A simple machine uses a single applied force to do work against a single load force. Ignoring friction losses, the work done on the load is equal to the work done by the applied force. The machine can increase the amount of the output force, at the cost of a proportional decrease in the distance moved by the load. The ratio of the output to the applied force is called the ''mechanical advantage''. Simple machines can be regarded as the elementary "building blocks" of which all more complicated machines (sometimes called "compound machines") are composed. For example, wheels, levers, and pu ... [...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 carbon, other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronze
Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids such as arsenic or silicon. These additions produce a range of alloys that may be harder than copper alone, or have other useful properties, such as ultimate tensile strength, strength, ductility, or machinability. The three-age system, archaeological period in which bronze was the hardest metal in widespread use is known as the Bronze Age. The beginning of the Bronze Age in western Eurasia and India is conventionally dated to the mid-4th millennium BCE (~3500 BCE), and to the early 2nd millennium BCE in China; elsewhere it gradually spread across regions. The Bronze Age was followed by the Iron Age starting from about 1300 BCE and reaching most of Eurasia by about 500 BCE, although bronze continued to be much more widely used than it is in mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form ( native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
