Online Etymology Dictionary
The Online Etymology Dictionary is a free online dictionary that describes the origins of English-language words. Douglas Harper compiled the etymology dictionary to record the history and evolution of more than 30,000 words, including slang, the core body of its etymology information stems from Ernest Weekleys An Etymological Dictionary of Modern English. Other sources include the Middle English Dictionary and the Barnhart Dictionary of Etymology, in producing his large dictionary, Douglas Harper says that he is essentially and for the most part a compiler, an evaluator of etymology reports which others have made. Harper works as a Copy editor/Page designer for LNP Media Group, as of June 2015, there were nearly 50,000 entries in the dictionary. It is cited in articles as a source for explaining the history
A fastener is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints, that is, welding is an example of creating permanent joints. There are special-purpose closing devices, e. g. a bread clip, furniture supplied in flat-pack form often uses cam dowels locked by cam locks, known as conformat fasteners. Items like a rope, wire, chain, or plastic wrap may be used to mechanically join objects, but are not generally categorized as fasteners because they have additional common uses. Likewise and springs may join together, but are ordinarily not considered fasteners because their primary purpose is to allow articulation rather than rigid affixment. Other alternative methods of joining materials include, welding, brazing, gluing, the use of force may be used, such as with magnets, vacuum, or even friction. There are three major steel fasteners used in industries, stainless steel, carbon steel, and alloy steel, the major grade used in stainless steel fasteners,200 series,300 series, and 400 series.
In 2005, it is estimated that the United States fastener industry runs 350 manufacturing plants, the industry is strongly tied to the production of automobiles, appliances, agricultural machinery, commercial construction, and infrastructure. More than 200 billion fasteners are used per year in the U. S.26 billion of these by the automotive industry, the largest distributor of fasteners in North America is the Fastenal Company. When selecting a fastener for industrial applications, it is important to consider a variety of factors, the threading, the applied load on the fastener, the stiffness of the fastener, and the number of fasteners needed should all be taken into account. Industrial Fastener Materials There are three major steel fasteners used in industries, stainless steel, carbon steel, and alloy steel, the major grade used in stainless steel fasteners,200 series,300 series, and 400 series. Titanium and various alloys are common materials of construction for metal fasteners. In many cases, special coatings or plating may be applied to metal fasteners to improve their performance characteristics by, for example, common coatings/platings include zinc and hot dip galvanizing.
When choosing a fastener for an application, it is important to know the specifics of that application to help select the proper material for the intended use. External thread, thread on the outside of a fastener, internal thread, thread on the inside of a fastener. Right hand thread, thread is “right hand” when, viewed axially, it winds in a clockwise and receding direction around the fastener, all threads are right hand unless otherwise designated. Left hand thread, thread is “left hand” when, viewed axially, it winds in a counterclockwise and receding direction around the fastener, left hand threads are designated LH. Pitch, the distance from one point on a thread to a corresponding point on an adjacent thread, pitch is measured parallel to its axis in the same axial plane
A spring pin is a mechanical fastener that secures the position of two or more parts of a machine relative to each other. Spring pins have a diameter which is larger than the hole diameter. The spring action of the pin allows it to compress as it assumes the diameter of the hole, the force exerted by the pin against the hole wall retains it in the hole, therefore a spring pin is considered a self retaining fastener. Spring pins are designed for use in double shear applications, there are two types of spring pins, slotted spring pins and coiled spring pins. A coiled spring pin, known as a pin, is a self retaining engineered fastener manufactured by roll forming metal strip into a spiral cross section of 2 1/4 coils. When coiled spring pins are installed, the starts at the outer edge. Coiled pins continue to flex after insertion when a load is applied to the pin thus providing excellent performance to counter fatigue in dynamic applications, coiled spring pins were invented by Herman Koehl circa 1948.
Typical materials for coiled spring pins include high carbon steel, stainless steel, coiled pins are used extensively in cosmetic cases, automotive door handles and locks, and latches as hinge pins. They are used as pivots and axles, for alignment and stopping, to fasten multiple components together—such as a gear, the automotive and electrical industries use coiled pins in such products as steering boxes and columns, electric motors and circuit breakers. Heavy duty coiled spring pins are used in high shear strength applications. Light duty pins are used in applications with soft metals and plastics holes where there is a risk of enlarging or breaking the host using a traditional press fit solid pin. Slotted spring pins are cylindrical pins rolled from a strip of material with a slot to allow the pin to have some flexibility during insertion, slotted spring pins are known as roll pins or C pins. Split pin Parmley, Standard handbook of fastening and joining
To assist insertion the end of the bent leg is angled away from the straight leg. This angled end rides the side of the shaft and opens the belly mouth enough to pass the widest part of the shaft as the R-clip is inserted, there is a double loop variety when a wider range of suitable shafts is required. It spreads out the stresses more evenly for a longer life and this type of pin is usually made of round wire of a harder metal than is appropriate for traditional cotter pins. R-clips are similar in function to split pins and linchpins, compared to split pins, they are easier to remove and are re-usable. Hitch pin clip Hood pin Button attachment Body fastener Bowtie cotter pin Hairpin clip Linchpin Split pin
The three-point hitch is a widely used type of hitch for attaching ploughs and other implements to an agricultural or industrial tractor. The three points resemble either a triangle, or the letter A. Three-point attachment is the simplest, a three-point hitch attaches the implement to the tractor so that the orientation of the implement is fixed with respect to the tractor and the arm position of the hitch. The tractor carries some or all of the weight of the implement, the other main mechanism for attaching a load is through a drawbar, a single point, pivoting attachment where the implement or trailer is not in a fixed position with respect to the tractor. The primary benefit of the three-point hitch system is to transfer the weight and this gives the tractor more usable traction than it would otherwise have, given the same power and fuel consumption. At 2,500 pounds, the 9N could plow more than 12 acres in a normal day pulling two 14-inch plows, outperforming the tractive performance of the heavier and more expensive Farmall F-30 model, the hitchs utility and simplicity have since made it an industry standard.
The three-point hitch is made up of components working together. These include the hydraulic system, attaching points, the lifting arms. Three-point hitches are composed of three movable arms, the two lower arms—the hitch lifting arms—are controlled by the hydraulic system, and provide lifting and even tilting to the arms. The upper center arm—called the top link—is movable, but is not powered by the tractors hydraulic system. Each arm has an attachment device to connect implements to the hitch, each hitch has attachment holes for attaching implements, and the implement has posts that fit through the holes. The implement is secured by placing a pin on the ends of the posts, the hitch lifting arms are powered by the tractors own hydraulic system. The hydraulic system is controlled by the operator, and usually a variety of settings are available, a draft control mechanism is often present in modern three-point hitch systems. There are five different hitch sizes, called categories, the higher category hitches have sturdier lift arms and larger connector pins.
Refers to implement end, Tractor end not specified, before the 1940s, most hitching of farm implements to tractors was done simply with a drawbar, on the same principle as a modern tow hitch. The drawbar was a bar with holes in it. The main reason why this was the default hitching idea is that it was the natural follow-on from the days of horse-drawn implements, which were towed as trailers by the horse or team. Towing with a drawbar is a good, practical system for many purposes, and it has continued to be used even up to today, Harry Ferguson patented the three-point linkage for agricultural tractors in Britain in 1926. He had long been a champion of the importance of rigid attachment of the plough to the tractor, the idea did not originate with him, but he led its popularization over many years of development and selling
A tractor is an engineering vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction. Most commonly, the term is used to describe a farm vehicle that provides the power and traction to mechanize agricultural tasks, especially tillage, but nowadays a great variety of tasks. Agricultural implements may be towed behind or mounted on the tractor, the word tractor was taken from Latin, being the agent noun of trahere to pull. The first recorded use of the meaning an engine or vehicle for pulling wagons or ploughs occurred in 1901. In Canada and the USA, the word may refer to the road tractor portion of a tractor trailer truck. The first powered farm implements in the early 19th century were portable engines – steam engines on wheels that could be used to drive farm machinery by way of a flexible belt. Richard Trevithick designed the first semi-portable stationary steam engine for use, known as a barn engine in 1812.
The truly portable engine was invented in 1839 by William Tuxford of Boston, a large flywheel was mounted on the crankshaft, and a stout leather belt was used to transfer the drive to the equipment being driven. In the 1850s, John Fowler used a Clayton & Shuttleworth portable engine to drive apparatus in the first public demonstrations of the application of cable haulage to cultivation. In parallel with the portable engine development, many engineers attempted to make them self-propelled – the fore-runners of the traction engine. In most cases this was achieved by fitting a sprocket on the end of the crankshaft and these experiments met with mixed success. The alteration was made by fitting a long driving chain between the crankshaft and the rear axle. The first half of the 1860s was a period of great experimentation but by the end of the decade the standard form of the engine had evolved. It was widely adopted for agricultural use, the first tractors were steam-powered plowing engines. They were used in pairs, placed on side of a field to haul a plow back.
In Britain Manns and Garrett developed steam tractors for direct ploughing, in the United States, where soil conditions permitted, steam tractors were used to direct-haul plows. Steam-powered agricultural engines remained in use well into the 20th century until reliable internal combustion engines had been developed, in 1892, John Froelich invented and built the first gasoline/petrol-powered tractor in Clayton County, Iowa, USA. A Van Duzen single-cylinder gasoline engine was mounted on a Robinson engine chassis, after receiving a patent, Froelich started up the Waterloo Gasoline Engine Company and invested all of his assets
A split pin, known in the United States as a cotter pin or cotter key, is a metal fastener with two tines that are bent during installation, similar to a staple or rivet. Typically made of wire with a half-circular cross section, split pins come in multiple sizes and types. The British definition of cotter pin is equivalent to U. S. term cotter, there are signs that manufacturers and stockists are increasingly listing both names together to avoid confusion, this led to the term split cotter sometimes being used for a split pin. A new split pin has its flat inner surfaces touching for most of its length so that it appears to be a split cylinder, once inserted, the two ends of the pin are bent apart, locking it in place. When they are removed they are supposed to be discarded and replaced, split pins are typically made of soft metal, making them easy to install and remove, but making it inadvisable to use them to resist strong shear forces. Common materials include steel, bronze, stainless steel.
As shown above, there are different types of ends available on split pins, the most common is the extended prong with a square cut, but extended prongs are available with all of the other types of ends. The extended prong type is popular because it makes it easier to separate the tines, to ease insertion into a hole the longer tine may be slightly curved to overlap the tip of the shorter tine or it is beveled. The length, L, of the pin is defined as the distance from the end of the shortest tine to the point of the eyelet that contacts the hole. Hammer lock split pins are installed by striking the head with a hammer to secure the pin. This forces the shorter tine forward, spreading the pin, standard Humped Clinch The diameter of split pins are standardized. American split pins start at 1⁄32 in and end at 3⁄4 in, split pins are frequently used to secure other fasteners, e. g. clevis pins, as well as being used in combination with hardboard discs as a traditional joining technique for teddy bears. A common application of this is used to secure a castellated nut.
Split pins may be used in applications as low-tech shear pins. Coiled spring pins Linchpin R-clip Bibliography
A wheel is a circular component that is intended to rotate on an axle bearing. The wheel is one of the components of the wheel. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, wheels are used for other purposes, such as a ships wheel, steering wheel, potters wheel and flywheel. Common examples are found in transport applications, a wheel greatly 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, cognates within Indo-European include Icelandic hjól wheel, Greek κύκλος kúklos, and Sanskrit chakra, the latter both meaning circle or wheel. The invention of the falls into the late Neolithic. Note that this implies the passage of several wheel-less millennia even after the invention of agriculture and of pottery, precursors of wheels, known as tournettes or slow wheels, were known in the Middle East by the 5th millennium BCE.
These were made of stone or clay and secured to the ground with a peg in the center, but required effort to turn. True potters wheels were apparently in use in Mesopotamia by 3500 BCE and possibly as early as 4000 BCE, and the oldest surviving example, which was found in Ur, dates to approximately 3100 BCE. The earliest well-dated depiction of a vehicle is on the Bronocice pot. The oldest securely dated real wheel-axle combination, that from Stare Gmajne near Ljubljana in Slovenia is now dated in 2σ-limits to 3340–3030 BCE, the axle to 3360–3045 BCE. Two types of early Neolithic European wheel and axle are known, a type of wagon construction. They both are dated to c, in China, the wheel was certainly present with the adoption of the chariot in c.1200 BCE, although Barbieri-Low argues for earlier Chinese wheeled vehicles, c.2000 BC. In Britain, a wooden wheel, measuring about 1 m in diameter, was uncovered at the Must Farm site in East Anglia in 2016. The specimen, dating from 1, 100–800 years BCE, represents the most complete, the wheels hub is present. A horses spine found nearby suggests the wheel may have part of a horse-drawn cart.
The wheel was found in a settlement built on stilts over wetland and it is thought that the primary obstacle to large-scale development of the wheel in the Americas was the absence of domesticated large animals which could be used to pull wheeled carriages. The only large animal that was domesticated in the Western hemisphere, Nubians from after about 400 BCE used wheels for spinning pottery and as water wheels
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating them, or fixed to the vehicle. In the former case, bearings or bushings are provided at the points where the axle is supported. In the latter case, a bearing or bushing sits inside a hole in the wheel to allow the wheel or gear to rotate around the axle. Sometimes, especially on bicycles, the latter type axle is referred to as a spindle, on cars and trucks, several senses of the word axle occur in casual usage, referring to the shaft itself, its housing, or simply any transverse pair of wheels. Strictly speaking, a shaft which rotates with the wheel, being either bolted or splined in fixed relation to it, is called an axle or axle shaft, however, in looser usage an entire assembly including the surrounding axle housing is called an axle. An even broader sense of the word refers to every pair of wheels on opposite sides of the vehicle, regardless of their mechanical connection to each other.
Thus, transverse pairs of wheels in an independent suspension may be called an axle in some contexts, axles are an integral component of most practical wheeled vehicles. In a live-axle suspension system, the serve to transmit driving torque to the wheel, as well as to maintain the position of the wheels relative to each other. The axles in this system must bear the weight of the vehicle plus any cargo. A non-driving axle, such as the front beam axle in heavy duty trucks and some 2-wheel drive light trucks and vans, will have no shaft, many front wheel drive cars have a solid rear beam axle. In other types of systems, the axles serve only to transmit driving torque to the wheels. This is typical of the independent suspension found on most newer cars and SUVs and these systems still have a differential, but it will not have attached axle housing tubes. It may be attached to the frame or body, or integral in a transaxle. The axle shafts transmit driving torque to the wheels, like a full floating axle system, the drive shafts in a front wheel drive independent suspension system do not support any vehicle weight. A straight axle is a rigid shaft connecting a wheel on the left side of the vehicle to a wheel on the right side.
The axis of rotation fixed by the axle is common to both wheels, such a design can keep the wheel positions steady under heavy stress, and can therefore support heavy loads. Straight axles are used on trains, for the axles of commercial trucks
This stage of the development of the English language roughly followed the High to the Late Middle Ages. Middle English developed out of Late Old English, seeing many dramatic changes in its grammar and this largely forms the basis for Modern English spelling, although pronunciation has changed considerably since that time. Middle English was succeeded in England by the era of Early Modern English, by that time, a variant of the Northumbrian dialect was developing into the Scots language. During the Middle English period many Old English grammatical features were simplified or disappeared, noun and verb inflections were simplified, a process that included the reduction of most grammatical case distinctions. Middle English saw an adoption of Norman French vocabulary, especially in areas such as politics, law. Everyday English vocabulary remained mostly Germanic, with Old Norse influence becoming apparent, significant changes in pronunciation took place, especially for long vowels and diphthongs, which in the Middle English period began to undergo the Great Vowel Shift.
Little survives of early Middle English literature, most likely due to the Norman domination, poets wrote both in the vernacular and courtly English. It is popularly believed that William Shakespeare wrote in Middle English, the latter part of the 11th century was a period of transition from Late Old English to Early Middle English. The influence of Old Norse certainly helped move English from a synthetic language towards a more analytic or isolating word order and it was, after all, a salutary influence. The gain was greater than the loss, there was a gain in directness, in clarity, and in strength. The change to Old English from Old Norse was substantive, pervasive and it is most important to recognise that in many words the English and Scandinavian language differed chiefly in their inflectional elements. The body of the word was so nearly the same in the two languages only the endings would put obstacles in the way of mutual understanding. In the mixed population which existed in the Danelaw these endings must have led to confusion, tending gradually to become obscured.
This blending of peoples and languages resulted in simplifying English grammar. There are many Norman-derived terms relating to the cultures that arose in the 12th century. Sometimes, and particularly later, words were taken from Latin, giving such sets as kingly, French borrowings came from standard rather than Norman French, this leads to such cognate pairs as warden, guardian. The end of Anglo-Saxon rule did not, of course, change the language immediately, the general population would have spoken the same dialects as before the Conquest, these changed slowly until written records of them became available for study, which varies in different regions. Once the writing of Old English came to an end, Middle English had no standard language, Early Middle English has a largely Anglo-Saxon vocabulary, but a greatly simplified inflectional system