Editing Leaf spring (section)

==History==
[[File:Lisbobspring.jpg|thumb|17th-century coach spring in Lisbon Carriage Museum]]
The earliest known leaf springs began appearing on carriages in France in the mid-17th century in the form of the two-part elbow spring (as the illustrated example from Lisbon), and later migrated to England and Germany,<ref>{{cite journal |last1=Terrier |first1=Max |title=L'invention des ressorts de voiture |journal=Revue d'Histoire des Sciences |date=1986 |volume=39 |issue=1 |pages=17–30|doi=10.3406/rhs.1986.4016 }}</ref> appearing on the carriages of the wealthy in those countries around 1750.<ref name="Sheldon">{{cite book|title=Leaf Springs: Their Characteristics and Methods of Specification|date=1912|publisher=Sheldon Axle Company|location=Wilkesbarre, PA |url=https://archive.org/details/leafspringstheir00land}}</ref>{{rp|1}} Dr. [[Richard Lovell Edgeworth]] was awarded three gold medals by the [[Royal Society of Arts|Society of English Arts and Manufacturers]] in 1768 for demonstrating the superiority of sprung carriages. By 1796, [[William Felton (coachmaker)|William Felton]]'s ''A Treatise on Carriages'' showed that leaf springs were being marketed regularly by the late 18th century carriage industry.{{r|felton|pp=87-97}}<ref name=Sheldon/>{{rp|1}}

Obadiah Elliot is credited with inventing the modern leaf spring with his 1804 patent on elliptical leaf springs, which brought him significant recognition and revenue, and engineers began studying leaf springs to develop improved designs and manufacturing processes. The mechanics and deflection of leaf springs were developed by Clark (1855), [[Franz Reuleaux]] (1861),<ref>{{cite book |url=https://books.google.com/books?id=m5U5AAAAcAAJ |title=Der Konstrukteur |author=Reuleaux, Franz |date=1861 |publisher=F. Vieweg |location=Braunschweig |access-date=13 October 2022}}</ref> and G.R. Henderson (1894).<ref name=Sheldon/>{{rp|1}}<ref name=Rowland>{{cite journal |jstor=44579553 |author=Rowland, E.K. |title=Leaf Springs |journal=Transactions |date=1911 |volume=6 |pages=156–191 |publisher=Society of Automobile Engineers}}</ref><ref name=Henderson-1894>{{cite journal |url=https://books.google.com/books?id=XkESAAAAIAAJ&pg=PA92 |title=A Graphical Method of Designing Springs |author=Henderson, G.R. |date=1894 |journal=Transactions |volume=XVI |pages=92–105 |publisher=American Society of Mechanical Engineers |access-date=13 October 2022}}</ref> Improved steel rolling processes, process instruments, and spring steel alloys were developed during the latter half of the 19th century as well, making the manufacture of leaf springs more consistent and less expensive.<ref name=Sheldon/>{{rp|2}}

[[File:Leaf spring on a train.jpg|thumb|upright=1.2|Leaf spring on a German [[locomotive]] built by [[Orenstein & Koppel|Orenstein-Koppel]] and Lübecker Maschinenbau]]
Leaf springs were very common on [[automobiles]] until the 1970s when [[automobile manufacturer]]s shifted primarily to [[front-wheel drive]], and more sophisticated [[suspension (vehicle)|suspension]] designs were developed using [[coil spring]]s instead. Today leaf springs are still used in heavy commercial vehicles such as [[van]]s and [[truck]]s, [[SUV]]s, and [[railway carriage]]s. For heavy vehicles, they have the advantage of spreading the load more widely over the vehicle's chassis, whereas coil springs transfer it to a single point. Unlike coil springs, leaf springs also locate the rear axle, eliminating the need for [[trailing arm]]s and a [[Panhard rod]], thereby saving cost and weight in a simple [[live axle]] rear suspension. A further advantage of a leaf spring over a helical spring is that the end of the leaf spring may be guided along a definite path. In many late 1990s and early 2000s trucks, the leaf spring is connected to a Hinkle Beam ball joint.
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<gallery mode="packed" heights="150px" widths="200px" caption="Leaf springs used in independent suspensions">
File:1928AlvisModelFD1275-FrontSuspension.jpg|Leaf-spring front independent suspension. Front-wheel-drive [[Alvis Car and Engineering Company Ltd|Alvis]], 1928
File:Humber front suspension (Autocar Handbook, 13th ed, 1935).jpg|Independent front suspension by transverse leaf spring. [[Humber Limited|Humber]], 1935
Image:MBW153chassis.jpg|Independent front suspension by semi-elliptical springs. Mercedes Benz 230 W153, 1938
</gallery>
The leaf spring also has seen modern applications in cars. For example, the [[Chevrolet Corvette (C2)|1963 Chevrolet Corvette Sting Ray]] uses a transverse leaf spring for its independent rear suspension. Similarly, [[Volvo XC90#|2016 Volvo XC90]] has a transverse leaf spring using composite materials for its rear suspension, similar in concept to [[Corvette leaf spring|the front suspension]] of the [[Chevrolet Corvette (C4)|1983 Corvette]]. This arrangement uses a straight leaf spring that is tightly secured to the chassis at the centre; the ends of the spring are bolted to the wheel suspension, allowing the spring to work independently on each wheel. This suspension is smaller, flatter and lighter than a traditional setup.