A locking differential is designed to overcome the chief limitation of a standard open differential by "locking" both wheels on an axle together as if on a common shaft. This forces both wheels to turn in unison, regardless of the traction available to either wheel individually; when the differential is unlocked, it allows each wheel to rotate at different speeds, thus avoiding tire scuffing. An open differential always provides the same torque on that axle. So although the wheels can rotate at different speeds, they apply the same rotational force if one is stationary, the other spinning.. By contrast, a locked differential forces both left and right wheels on the same axle to rotate at the same speed under nearly all circumstances, without regard to tractional differences seen at either wheel. Therefore, each wheel can apply as much rotational force as the traction under it will allow, the torques on each side-shaft will be unequal.. Exceptions apply to automatic lockers, discussed below. A locked differential can provide a significant traction advantage over an open differential, but only when the traction under each wheel differs significantly.
All the above comments apply to central differentials as well as to those in each axle: full-time four-wheel-drive vehicles have three differentials, one in each axle, a central one between the front and rear axles. Automatic lockers unlock automatically with no direct input from the driver; some automatic locking differential designs ensure that engine power is always transmitted to both wheels, regardless of traction conditions, will "unlock" only when one wheel is required to spin faster than the other during cornering. These would be more termed "automatic unlocking" differentials, because their at-rest position is locked, they will never allow either wheel to spin slower than the differential carrier or axle as a whole, but will permit a wheel to be over-driven faster than the carrier speed. The most common example of this type would be the famous "Detroit Locker," made by Eaton Corporation known as the "Detroit No-Spin," which replaces the entire differential carrier assembly. Others, sometimes referred to as "lunchbox lockers," employ the stock differential carrier and replace only the internal spider gears and shafts with interlocking plates.
Both types of automatic lockers will allow for a degree of differential wheel speed while turning corners in conditions of equal traction, but will otherwise lock both axle shafts together when traction conditions demand it. Pros: Automatic action, no driver interaction necessary, no stopping for engagement necessary, continuous driving in unforeseen road condition changes Cons: Increased tire wear and noticeable impact on driving behavior. During cornering, which half-axle is uncoupled is dependent on torque direction applied by the driveline; when the torque direction is reversed, the speed of the driveline is forced to change from the inner to outer axle, accompanied by tire chirping and a large jerk. During cornering, the automatic locker is characterized by heavy understeer which transitions to power oversteer when traction is exceeded; some other automatic lockers operate as an open differential until wheel slip is encountered and they lock up. This style uses an internal governor to monitor vehicle speed and wheel slip.
An example of this is the Eaton Automatic Locking Differential, or Eaton Automatic Differential Lock, developed by the Eaton Corporation and introduced in 1973 for GM's Rounded-Line C/K Series pickups and utilities. The Eaton ADL is sometimes incorrectly called the "Gov-Lok", despite neither GM nor Eaton calling it by that name. "Gov-Lok" is rather an unofficial name of unknown origin. Both Eaton and GM do not know where the name came from, Eaton has made several unsuccessful attempts in the past to debunk the Gov-Lok name. An updated version of the old Eaton ADL design is still available from Eaton, now known as the Eaton mLocker mechanical differential lock; some other automatic lockers operate as an open differential until high torque is applied and they lock up. This style uses internal gears systems with high friction. An example of this is the ZF "sliding cams" available for use in early Volkswagens. Selectable lockers allow the driver to lock and unlock the differential at will from the driver's seat.
This can be accomplished many ways. Compressed air. Cable operated mechanism as is employed on the "Ox Locker." Electronic solenoids and like Eaton's "ELocker." However, OEMs are beginning to offer electronic lockers as well. Nissan Corporation's electric locker can be found as optional equipment on the Xterra. Pros: Allows the differential to perform as an "open" differential for improved driveability, provides full locking capability when it is desirable or needed Cons: Mechanically complex with more parts to fail; some lockers require vehicle to stop for engagement. Needs human interaction and forward-thinking regarding upcoming terrain. Unskilled drivers put massive stress on driveline components when leaving the differential in locked operation on terrain not requiring a locker. A spool is a device. There is no differentiation side to side, so a vehicle equipped with a spool will bark tires in turns and may become unmanageable in wet or snowy weather. Spools are rese
A car is a wheeled motor vehicle used for transportation. Most definitions of car say they run on roads, seat one to eight people, have four tires, transport people rather than goods. Cars came into global use during the 20th century, developed economies depend on them; the year 1886 is regarded as the birth year of the modern car when German inventor Karl Benz patented his Benz Patent-Motorwagen. Cars became available in the early 20th century. One of the first cars accessible to the masses was the 1908 Model T, an American car manufactured by the Ford Motor Company. Cars were adopted in the US, where they replaced animal-drawn carriages and carts, but took much longer to be accepted in Western Europe and other parts of the world. Cars have controls for driving, passenger comfort, safety, controlling a variety of lights. Over the decades, additional features and controls have been added to vehicles, making them progressively more complex; these include rear reversing cameras, air conditioning, navigation systems, in-car entertainment.
Most cars in use in the 2010s are propelled by an internal combustion engine, fueled by the combustion of fossil fuels. Electric cars, which were invented early in the history of the car, began to become commercially available in 2008. There are benefits to car use; the costs include acquiring the vehicle, interest payments and maintenance, depreciation, driving time, parking fees and insurance. The costs to society include maintaining roads, land use, road congestion, air pollution, public health, health care, disposing of the vehicle at the end of its life. Road traffic accidents are the largest cause of injury-related deaths worldwide; the benefits include on-demand transportation, mobility and convenience. The societal benefits include economic benefits, such as job and wealth creation from the automotive industry, transportation provision, societal well-being from leisure and travel opportunities, revenue generation from the taxes. People's ability to move flexibly from place to place has far-reaching implications for the nature of societies.
There are around 1 billion cars in use worldwide. The numbers are increasing especially in China and other newly industrialized countries; the word car is believed to originate from the Latin word carrus or carrum, or the Middle English word carre. In turn, these originated from the Gaulish word karros, it referred to any wheeled horse-drawn vehicle, such as a cart, carriage, or wagon. "Motor car" is attested from 1895, is the usual formal name for cars in British English. "Autocar" is a variant, attested from 1895, but, now considered archaic. It means "self-propelled car"; the term "horseless carriage" was used by some to refer to the first cars at the time that they were being built, is attested from 1895. The word "automobile" is a classical compound derived from the Ancient Greek word autós, meaning "self", the Latin word mobilis, meaning "movable", it entered the English language from French, was first adopted by the Automobile Club of Great Britain in 1897. Over time, the word "automobile" fell out of favour in Britain, was replaced by "motor car".
"Automobile" remains chiefly North American as a formal or commercial term. An abbreviated form, "auto", was a common way to refer to cars in English, but is now considered old-fashioned; the word is still common as an adjective in American English in compound formations like "auto industry" and "auto mechanic". In Dutch and German, two languages related to English, the abbreviated form "auto" / "Auto", as well as the formal full version "automobiel" / "Automobil" are still used — in either the short form is the most regular word for "car"; the first working steam-powered vehicle was designed — and quite built — by Ferdinand Verbiest, a Flemish member of a Jesuit mission in China around 1672. It was a 65-cm-long scale-model toy for the Chinese Emperor, unable to carry a driver or a passenger, it is not known with certainty if Verbiest's model was built or run. Nicolas-Joseph Cugnot is credited with building the first full-scale, self-propelled mechanical vehicle or car in about 1769, he constructed two steam tractors for the French Army, one of, preserved in the French National Conservatory of Arts and Crafts.
His inventions were, handicapped by problems with water supply and maintaining steam pressure. In 1801, Richard Trevithick built and demonstrated his Puffing Devil road locomotive, believed by many to be the first demonstration of a steam-powered road vehicle, it was unable to maintain sufficient steam pressure for long periods and was of little practical use. The development of external combustion engines is detailed as part of the history of the car but treated separately from the development of true cars. A variety of steam-powered road vehicles were used during the first part of the 19th century, including steam cars, steam buses and steam rollers. Sentiment against them led to the Locomotive Acts of 1865. In 1807, Nicéphore Niépce and his brother Claude created what was the world's first internal combustion engine, but they chose to install it in a boat on the river Saone in France. Coincidentally, in 1807 the Swiss inventor François Isaac de Rivaz designed his own'de Rivaz internal combustion engine' and used it to develop the world's first vehicle to be powered by such an engine.
An engine or motor is a machine designed to convert one form of energy into mechanical energy. Heat engines, like the internal combustion engine, burn a fuel to create heat, used to do work. Electric motors convert electrical energy into mechanical motion, pneumatic motors use compressed air, clockwork motors in wind-up toys use elastic energy. In biological systems, molecular motors, like myosins in muscles, use chemical energy to create forces and motion; the word engine derives from Old French engin, from the Latin ingenium–the root of the word ingenious. Pre-industrial weapons of war, such as catapults and battering rams, were called siege engines, knowledge of how to construct them was treated as a military secret; the word gin, as in cotton gin, is short for engine. Most mechanical devices invented during the industrial revolution were described as engines—the steam engine being a notable example. However, the original steam engines, such as those by Thomas Savery, were not mechanical engines but pumps.
In this manner, a fire engine in its original form was a water pump, with the engine being transported to the fire by horses. In modern usage, the term engine describes devices, like steam engines and internal combustion engines, that burn or otherwise consume fuel to perform mechanical work by exerting a torque or linear force. Devices converting heat energy into motion are referred to as engines. Examples of engines which exert a torque include the familiar automobile gasoline and diesel engines, as well as turboshafts. Examples of engines which produce thrust include rockets; when the internal combustion engine was invented, the term motor was used to distinguish it from the steam engine—which was in wide use at the time, powering locomotives and other vehicles such as steam rollers. The term motor derives from the Latin verb moto which means to maintain motion, thus a motor is a device. Motor and engine are interchangeable in standard English. In some engineering jargons, the two words have different meanings, in which engine is a device that burns or otherwise consumes fuel, changing its chemical composition, a motor is a device driven by electricity, air, or hydraulic pressure, which does not change the chemical composition of its energy source.
However, rocketry uses the term rocket motor though they consume fuel. A heat engine may serve as a prime mover—a component that transforms the flow or changes in pressure of a fluid into mechanical energy. An automobile powered by an internal combustion engine may make use of various motors and pumps, but all such devices derive their power from the engine. Another way of looking at it is that a motor receives power from an external source, converts it into mechanical energy, while an engine creates power from pressure. Simple machines, such as the club and oar, are prehistoric. More complex engines using human power, animal power, water power, wind power and steam power date back to antiquity. Human power was focused by the use of simple engines, such as the capstan, windlass or treadmill, with ropes and block and tackle arrangements; these were used in cranes and aboard ships in Ancient Greece, as well as in mines, water pumps and siege engines in Ancient Rome. The writers of those times, including Vitruvius and Pliny the Elder, treat these engines as commonplace, so their invention may be more ancient.
By the 1st century AD, cattle and horses were used in mills, driving machines similar to those powered by humans in earlier times. According to Strabo, a water powered mill was built in Kaberia of the kingdom of Mithridates during the 1st century BC. Use of water wheels in mills spread throughout the Roman Empire over the next few centuries; some were quite complex, with aqueducts and sluices to maintain and channel the water, along with systems of gears, or toothed-wheels made of wood and metal to regulate the speed of rotation. More sophisticated small devices, such as the Antikythera Mechanism used complex trains of gears and dials to act as calendars or predict astronomical events. In a poem by Ausonius in the 4th century AD, he mentions a stone-cutting saw powered by water. Hero of Alexandria is credited with many such wind and steam powered machines in the 1st century AD, including the Aeolipile and the vending machine these machines were associated with worship, such as animated altars and automated temple doors.
Medieval Muslim engineers employed gears in mills and water-raising machines, used dams as a source of water power to provide additional power to watermills and water-raising machines. In the medieval Islamic world, such advances made it possible to mechanize many industrial tasks carried out by manual labour. In 1206, al-Jazari employed a crank-conrod system for two of his water-raising machines. A rudimentary steam turbine device was described by Taqi al-Din in 1551 and by Giovanni Branca in 1629. In the 13th century, the solid rocket motor was invented in China. Driven by gunpowder, this simplest form of internal combustion engine was unable to deliver sustained power, but was useful for propelling weaponry at high speeds towards enemies in battle and for fireworks. After invention, this innovation spread throughout Europe; the Watt steam engine was the first type of steam engine to make use of steam at a pressure just above atmospheric to drive the piston he
The Michel Irat was a French automobile manufactured from 1929 until 1930 in Paris. Georges Irat changed its name to that of his son Michel. Production continued of the old models. In 1930 Georges Irat combined the company with his own larger operation. At least one example survives in private ownership in England, whilst another was rumoured to exist in Belgium in 1985. David Burgess Wise, The New Illustrated Encyclopedia of Automobiles
Chatou is a commune in the Yvelines department in the Île-de-France region in north-central France. Chatou is a part of the affluent suburbs of western Paris and is on the northwest side of the Seine river about 14 km from the city's center. On May 31, 1875, part of the territory of Chatou was detached and merged with a part of the territory of Le Pecq and a part of the territory of Croissy-sur-Seine to create the commune of Le Vésinet, it owned by private individuals. Chatou is the host of the Maison Fournaise, a meeting place for Impressionist painters in the past, it was a place where Pierre-Auguste Renoir painted numerous pieces, most notably the Déjeuner des canotiers in 1881. The painting is today part of the Phillips Collection in Washington, D. C. On August 25, 1944, in Chatou, the nazis shot 27 people and members of the French Resistance; this event is today known as the "Massacre des 27 Martyrs". Chatou is served by Chatou – Croissy station on Paris RER line A; the community has eight public preschools, five public elementary schools, two public junior high schools.
Schools include:Elementary: Les Champs-Moutons Jules Ferry Victor Hugo Jean Rostand Val FleuriJunior high schools: Collège Paul Bert Collège Auguste RenoirThere are the following private schools: École Jeanne d'Arc / Notre-Dame École Perceval Lycée Alain, a public senior high school/sixth form college. Parks include: Parc des Impressionnistes Parc Auguste Renoir Parc de l’Europe Jardin du Sentier de la Côte Square Emile Pathé Square Réalier-Dumas Hameau Fournaise, Île des Impressionnistes Communes of the Yvelines department Official website
Free France and its Free French Forces were the government-in-exile led by Charles de Gaulle during the Second World War and its military forces, that continued to fight against the Axis powers as one of the Allies after the fall of France. Set up in London in June 1940, it supported the Resistance in occupied France. Charles de Gaulle, a French government minister who rejected the armistice concluded by Marshal Philippe Pétain and who had escaped to Britain, exhorted the French to resist in his BBC broadcast "Appeal of 18 June", which had a stirring effect on morale throughout France and its colonies, although relatively few French forces responded to de Gaulle's call for resistance. On 27 October 1940, the Empire Defense Council was constituted to organise the rule of the territories in central Africa and Oceania that had heeded the 18 June call, it was replaced on 24 September 1941 by the French National Committee. On 13 July 1942, "Free France" was renamed France combattante, to mark that the struggle against the Axis was conducted both externally by the FFF and internally by the French Forces of the Interior.
After the reconquest of North Africa, this was in turn formally merged with de Gaulle's rival general Henri Giraud's command in Algiers to form the French Committee of National Liberation. Exile ended with the liberation of Paris by the 2nd Armoured Free French Division and Resistance forces on 25 August 1944, ushering in the Provisional Government of the French Republic, it ruled France until the end of the war and afterwards to 1946, when the Fourth Republic was established, thus ending the series of interim regimes that had succeeded the Third Republic after its fall in 1940. The Free French fought Axis and Vichy regime troops and served on battlefronts everywhere from the Middle East to Indochina and North Africa; the Free French Navy operated as an auxiliary force to the Royal Navy and, in the North Atlantic, to the Royal Canadian Navy. Free French units served in the Royal Air Force, Soviet Air Force, British SAS, before larger commands were established directly under the control of the government-in-exile.
From colonial outposts in Africa and the Pacific, Free France took over more and more Vichy possessions, until after the Allied landings in North Africa in November 1942 Vichy only ruled over the zone libre in southern France and a few possessions in the West Indies. The French Army of Africa switched allegiance to Free France, this caused the Axis to occupy Vichy in reaction. On August 1, 1943, L'Armée d'Afrique was formally united with the Free French Forces to form L'Armée française de la Liberation. By mid-1944, the forces of this army numbered more than 400,000, they participated in the Normandy landings and the invasion of southern France leading the drive on Paris. Soon they were fighting in Alsace, the Alps and Brittany, by the end of the war in Europe, they were 1,300,000 strong—the fourth-largest Allied army in Europe—and took part in the Allied advance through France and invasion of Germany; the Free French government re-established a provisional republic after the liberation, preparing the ground for the Fourth Republic in 1946.
An individual became "Free French" by enlisting in the military units organised by the CFN or by employment by the civilian arm of the Committee. On 1 August 1943 after the merger of CFN and representatives of the former Vichy regime in North Africa to form the CFLN earlier in June, the FFF and the Armée d'Afrique were merged to form the French Liberation Army, Armée française de la Libération, all subsequent enlistments were in this combined force. In many sources, Free French describes any French individual or unit that fought against Axis forces after the June 1940 armistice. Postwar, to settle disputes over the Free French heritage, the French government issued an official definition of the term. Under this "ministerial instruction of July 1953", only those who served with the Allies after the Franco-German armistice in 1940 and before 1 August 1943 may be called "Free French". On 10 May 1940, Nazi Germany invaded France and the Low Countries defeating the Dutch and Belgians, while armoured units attacking through the Ardennes cut off the Franco-British strike force in Belgium.
By the end of May, the British and French northern armies were trapped in a series of pockets, including Dunkirk, Boulogne, Saint-Valery-en-Caux and Lille. The Dunkirk evacuation was only made possible by the resistance of these troops the French army divisions at Lille. From 27 May to 4 June, over 200,000 members of the British Expeditionary Force and 140,000 French troops were evacuated from Dunkirk. Neither side viewed this as the end of the battle. After being evacuated from Dunkirk, Alanbrooke landed in Cherbourg on 2 June to reform the BEF, along with the 1st Canadian Division, the only remaining armoured unit in Britain. Contrary to what is assumed, French morale was higher in June than May and they repulsed an attack in the south by Fascist Italy. A defensive line was re-established along the Somme but much of the armour was lost in Northern France.
Battle of France
The Battle of France known as the Fall of France, was the German invasion of France and the Low Countries during the Second World War. In the six weeks from 10 May 1940, German forces defeated Allied forces by mobile operations and conquered France, Belgium and the Netherlands, bringing land operations on the Western Front to an end until 6 June 1944. Italy invaded France over the Alps. In Fall Gelb, German armoured units pushed through the Ardennes and along the Somme valley, cutting off and surrounding the Allied units that had advanced into Belgium, to meet the expected German invasion; when British and French forces were pushed back to the sea by the mobile and well-organised German operation, the British evacuated the British Expeditionary Force and French divisions from Dunkirk in Operation Dynamo. German forces began Fall Rot on 5 June; the sixty remaining French divisions and two British divisions made a determined resistance but were unable to overcome the German air superiority and armoured mobility.
German tanks outflanked the Maginot Line and pushed deep into France, occupying Paris unopposed on 14 June. After the flight of the French government and the collapse of the French army, German commanders met with French officials on 18 June to negotiate an end to hostilities. On 22 June, the Second Armistice at Compiègne was signed by Germany; the neutral Vichy government led by Marshal Philippe Pétain superseded the Third Republic and Germany occupied the north and west coasts of France and their hinterlands. Italy took control of a small occupation zone in the south-east and the Vichy regime retained the unoccupied territory in the south, known as the zone libre. In November 1942, the Germans occupied the zone under Case Anton, until the Allied liberation in 1944. During the 1930s, the French built fortifications along the border with Germany; the line was intended to economise on manpower and deter a German invasion across the Franco-German border by diverting it into Belgium, which could be met by the best divisions of the French Army.
The war would take place outside French territory avoiding the destruction of the First World War. The main section of the Maginot Line ended at Longwy. General Philippe Pétain declared the Ardennes to be "impenetrable" as long as "special provisions" were taken to destroy an invasion force as it emerged from the Ardennes by a pincer attack; the French commander-in-chief, Maurice Gamelin believed the area to be safe from attack, noting it "never favoured large operations". French war games held in 1938, of a hypothetical German armoured attack through the Ardennes, left the army with the impression that the region was still impenetrable and that this, along with the obstacle of the Meuse River, would allow the French time to bring up troops into the area to counter an attack. In 1939, Britain and France offered military support to Poland in the case of a German invasion. In the dawn of 1 September 1939, the German Invasion of Poland began. France and the United Kingdom declared war on 3 September, after an ultimatum for German forces to withdraw their forces from Poland was not answered.
Following this, New Zealand, South Africa and Canada declared war on Germany. While British and French commitments to Poland were met politically, the Allies were not in a position to render meaningful military assistance to the Poles in a timely manner. If Allied military intervention in Poland had been feasible, it would have come at the risk of drawing the Soviet Union into the war on Germany's side due to the recently-signed German-Soviet non-aggression pact and subsequent Soviet invasion of eastern Poland; as a result, the Allies settled on a long-war strategy and mobilised for defensive land operations against Germany, while a trade blockade was imposed and the pre-war re-armament was accelerated, ready for an eventual invasion of Germany. On 7 September, in accordance with their alliance with Poland, France began the Saar Offensive with an advance from the Maginot Line 5 km into the Saar. France had mobilised 98 divisions and 2,500 tanks against a German force consisting of 43 divisions and no tanks.
The French advanced until they met the thin and undermanned Siegfried Line. On 17 September, the French supreme commander, Maurice Gamelin gave the order to withdraw French troops to their starting positions. Following the Saar Offensive, a period of inaction called the Phoney War set in between the belligerents. Adolf Hitler had hoped that France and Britain would acquiesce in the conquest of Poland and make peace. On 6 October, he made a peace offer to both Western powers. On 9 October, Hitler issued a new "Führer-Directive Number 6". Hitler recognised the necessity of military campaigns to defeat the Western European nations, preliminary to the conquest of territory in Eastern Europe, to avoid a two-front war but these intentions were absent from Directive N°6; the plan was based on the more realistic assumption that German military strength would have to be built up for several years. For the moment only limited objectives could be envisaged and were aimed at improving Germany's ability to survive a long war in the west.
Hitler ordered a conquest of the Low Countries to be executed at the shortest possible notice to forestall the French and prevent Allied air po