Double-clutching
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Double-clutching
Double-clutching (also called double de-clutching outside of the United States) is a method of shifting gears used primarily for vehicles with an unsynchronized manual transmission, such as commercial trucks and specialty vehicles. While double clutching is not necessary in a vehicle that has a synchronized manual transmission, the technique can be advantageous for smoothly upshifting in order to accelerate and, when done correctly, it prevents wear on the synchronizers which normally equalize transmission input and output speeds to allow downshifting. With this method, instead of pushing the clutch in once and shifting directly to another gear, the driver first engages the transmission in neutral before shifting to the next gear. The clutch is depressed and released with each change. A related downshifting/rev-matching technique is heel-and-toe shifting, in which the throttle is ''blipped'' (i.e. momentarily opened during downshifting) by the driver's heel during braking. Histo ...
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Synchromesh
A manual transmission (MT), also known as manual gearbox, standard transmission (in Canada, the United Kingdom, and the United States), or stick shift (in the United States), is a multi-speed motor vehicle transmission system, where gear changes require the driver to manually select the gears by operating a gear stick and clutch (which is usually a foot pedal for cars or a hand lever for motorcycles). Early automobiles used ''sliding-mesh'' manual transmissions with up to three forward gear ratios. Since the 1950s, ''constant-mesh'' manual transmissions have become increasingly commonplace and the number of forward ratios has increased to 5-speed and 6-speed manual transmissions for current vehicles. The alternative to a manual transmission is an automatic transmission; common types of automatic transmissions are the hydraulic automatic transmission (AT), and the continuously variable transmission (CVT), whereas the automated manual transmission (AMT) and dual-clutch transmissio ...
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Manual Transmission
A manual transmission (MT), also known as manual gearbox, standard transmission (in Canada, the United Kingdom, and the United States), or stick shift (in the United States), is a multi-speed motor vehicle transmission (mechanics), transmission system, where gear changes require the driver to manually select the gears by operating a gear stick and clutch (which is usually a foot pedal for cars or a hand lever for motorcycles). Early automobiles used ''sliding-mesh'' manual transmissions with up to three forward gear ratios. Since the 1950s, ''constant-mesh'' manual transmissions have become increasingly commonplace and the number of forward ratios has increased to 5-speed and 6-speed manual transmissions for current vehicles. The alternative to a manual transmission is an automatic transmission; common types of automatic transmissions are the Automatic transmission#Hydraulic automatic transmissions, hydraulic automatic transmission (AT), and the continuously variable transmissio ...
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Unsynchronized Manual Transmission
A non-synchronous transmission, also called a crash gearbox, is a form of manual transmission based on gears that do not use synchronizing mechanisms. They require the driver to manually synchronize the transmission's input speed (engine RPM) and output speed (driveshaft speed). Non-synchronous transmissions are found primarily in various types of industrial machinery; such as tractors and semi-tractors. Non-synchronous manual transmissions are also found on motorcycles, in the form of constant-mesh sequential manual transmissions. Prior to the 1950s and 1960s, most cars used constant-mesh (and also sliding-mesh) but non-synchronous transmissions. History Most early automobiles were rear-engined, using a single-speed transmission and belt-drive to power the rear wheels. In 1891, the French Panhard et Levassor automobile used a three-speed manual transmission and is considered to have set the template for multi-speed manual transmissions in motor vehicles. This transmission ...
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Clutch
A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). In these devices, one shaft is typically attached to an engine or other power unit (the driving member), while the other shaft (the driven member) provides output power for work. Typically the motions involved are rotary, but linear clutches also exist. In a motor vehicle, the clutch acts as a mechanical linkage between the engine and transmission, and briefly disconnects, or separates the engine from the transmission system. This disconnects the drive wheels whenever the clutch pedal is depressed, allowing the driver to smoothly change gears. In a torque-controlled drill, for instance, one shaft is driven by a motor, and the other drives a drill chuck. The clutch connects the two shafts so they may be locked together and spin at the ...
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Heel-and-toe Shifting
Heel-and-toe shifting is an advanced driving technique used mostly in performance driving with a manual gearbox, although some drivers use it on the road in everyday conditions in the interest of effectiveness. It involves operating the throttle and brake pedals simultaneously with the right foot, while facilitating normal activation of the clutch with the left foot. It is used when braking and downshifting simultaneously (prior to entering a turn), and allows the driver to "blip" the throttle to raise the engine speed and smoothly engage the lower gear. (See synchronized transmission.) Usage Heel-and-toe shifting is used before entry into a turn while a vehicle is under braking, preparing the transmission to be in the optimal range of rpm to accelerate out of the turn. One benefit of downshifting before entering a turn is to eliminate the jolt to the drivetrain, or any other unwanted dynamics. The jolt will not upset the vehicle as badly when going in a straight line, but the sa ...
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Tractor Unit
A tractor unit (also known as a truck unit, power unit, prime mover, ten-wheeler, semi-tractor, tractor truck, semi-truck, tractor cab, truck cab, tractor rig, truck rig or big rig or simply a tractor, truck, semi or rig) is a characteristically heavy-duty towing engine that provides motive power for hauling a towed or trailered load. These fall into two categories: heavy- and medium-duty military and commercial rear-wheel-drive semi-tractors used for hauling semi-trailers, and very heavy-duty typically off-road-capable, often 6×6, military and commercial tractor units, including ballast tractors. Overview Tractor units typically have large displacement diesel engines for power, durability, and economy; several axles; and a multi-ratio transmission (10, 13, or 18 gears) for maximum flexibility in gearing. The tractor-trailer combination distributes a load across multiple axles while being more maneuverable than an equivalently sized rigid truck. The most common traile ...
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Sequential Manual Transmission
A sequential manual transmission, also known as a sequential gearbox, or a sequential transmission, is a type of non-synchronous manual transmission used mostly for motorcycles and racing cars. It produces faster shift times than traditional synchronized manual transmissions, and restricts the driver to selecting either the next or previous gear, in a successive order. Design A sequential manual transmission is unsynchronized, and allows the driver to select either the next gear (e.g. shifting from first gear to second gear) or the previous gear (e.g., shifting from third gear to second gear), operated either via electronic paddle-shifters mounted behind the steering wheel or with a sequential shifter. This restriction avoids accidentally selecting the wrong gear; however, it also prevents the driver from deliberately "skipping" gears. The use of dog clutches (rather than synchromesh) results in faster shift speeds than a conventional manual transmission. On a sequentia ...
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Throttle
A throttle is the mechanism by which fluid flow is managed by constriction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases (by the use of a throttle), but usually decreased. The term ''throttle'' has come to refer, informally, to any mechanism by which the power or speed of an engine is regulated, such as a car's accelerator pedal. What is often termed a ''throttle'' (in an aviation context) is also called a thrust lever, particularly for jet engine powered aircraft. For a steam locomotive, the valve which controls the steam is known as the regulator. Internal combustion engines In an internal combustion engine, the throttle is a means of controlling an engine's power by regulating the amount of fuel or air entering the engine. In a motor vehicle the control used by the driver to regulate power is sometimes called the throttle, accelerator, or gas Automobile pedal, pedal. For a gasoline engine, the throttle most commonly regul ...
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Commercial Driver's License
A commercial driver's license (CDL) is a driver's license required in the United States to operate large and heavy vehicles (including trucks, buses, and trailers) or a vehicle of any size that transports hazardous materials or more than 15 passengers (including the driver). United States In the United States, the Commercial Motor Vehicle Safety Act of 1986 established minimum requirements that must be met when a state issues a CDL. In some states, a CDL may be required to drive a recreational vehicle or agricultural vehicle. However, such vehicles are federally exempt from having to obtain a CDL. The following types of CDL licenses are: *Class A – Any combination of vehicles that has a gross combination weight rating or gross combination weight of 26,001 pounds (11,794 kilograms) or more inclusive of a towed unit(s) with a gross vehicle weight rating or gross vehicle weight of more than 10,000 pounds (4,536 kilograms). *Class B – Any single vehicle which has a gross ve ...
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Float Shifting
Float shifting or floating gears, also called "slip shifting", "dead sticking" or "bang shifting", is the process of changing gears, in typically a non-synchronous transmission, without depressing the clutch. Shifting in this manner is also used with synchronous manual transmissions, particularly after a clutch failure, to prevent destroying the syncromeshes with the power of the engine. The most skillful drivers can shift non-synchronous transmissions without using the clutch by bringing the engine to exactly the right RPM in neutral before attempting to complete a shift. If done improperly, it can damage or destroy a transmission. Some truck (lorry) drivers use this technique with the higher gears when at work. The technique is sometimes also used on motorcycles, but has largely been replaced by quickshifters for competitive use. Technique To upshift, the driver should first bring the engine up to speed. They must then shift to neutral and apply moderate pressure to the gea ...
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Eaton Corporation
Eaton Corporation plc is an American-Irish multinational power management company with 2021 sales of $19.63 billion, founded in the United States with global headquarters in Dublin, Ireland, and a secondary administrative center in Beachwood, Ohio. Eaton has more than 86,000 employees and sells products to customers in more than 175 countries. History In 1911, Joseph O. Eaton, brother-in-law Henning O. Taube and Viggo V. Torbensen, incorporated the Torbensen Gear and Axle Co. in Bloomfield, New Jersey. With financial backing from Torbensen's mother, the company was set to manufacture Torbensen's patented internal-gear truck axle. In 1914, the company moved to Cleveland, Ohio, to be closer to its core business, the automotive industry. The Torbensen Axle Company incorporated in Ohio in 1916, succeeding the New Jersey corporation. A year later, Republic Motor Truck Company, Torbensen's largest customer bought out the company. But Eaton and Torbensen were not content and bowed ...
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YouTube
YouTube is a global online video platform, online video sharing and social media, social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by Google, and is the List of most visited websites, second most visited website, after Google Search. YouTube has more than 2.5 billion monthly users who collectively watch more than one billion hours of videos each day. , videos were being uploaded at a rate of more than 500 hours of content per minute. In October 2006, YouTube was bought by Google for $1.65 billion. Google's ownership of YouTube expanded the site's business model, expanding from generating revenue from advertisements alone, to offering paid content such as movies and exclusive content produced by YouTube. It also offers YouTube Premium, a paid subscription option for watching content without ads. YouTube also approved creators to participate in Google's Google AdSens ...
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