A traditional semi-elliptical leaf spring arrangement. On the left, the spring is connected to the frame through a shackle.

Quarter-elliptical spring in a 1937 Bugatti Type 57SC

Originally called laminated or carriage spring, a leaf spring is a simple form of spring, commonly used for the suspension in wheeled vehicles. Bugatti was founded in Molsheim, France, as a manufacturer of high performance automobiles by Ettore Bugatti, an Italian Type 57G Bugatti --> The famous Type 57G tank-bodied racers used the 57S chassis in 1936 and 1937 and the A spring is a flexible elastic object used to store mechanical Energy. Suspension is the term given to the system of springs, Shock absorbers and linkages that connects a Vehicle to its Wheels Suspension A wheel is a circular device that is capable of rotating on its axis facilitating movement or transportation whilst supporting a load ( Mass) or performing labour in machines Vehicles, derived from the Latin word vehiculum, are non-living Means of transport. It is also one of the oldest forms of springing, dating back to medieval times.

Sometimes referred to as a semi-elliptical spring or cart spring, it takes the form of a slender arc-shaped length of spring steel of rectangular cross-section. In Mathematics, an ellipse (from the Greek ἔλλειψις literally absence) is a Conic section, the locus of points in a In Geometry, an arc is a closed segment of a Differentiable Curve in the two-dimensional plane; for example a circular Spring steel is a low alloy Medium carbon steel with a very high Yield strength. In Geometry, a rectangle is defined as a Quadrilateral where all four of its angles are Right angles A rectangle with vertices ABCD would be denoted as The center of the arc provides location for the axle, while tie holes are provided at either end for attaching to the vehicle body. An axle is a central shaft for a rotating Wheel or Gear. In some cases the axle may be fixed in position with a bearing or Bushing For very heavy vehicles, a leaf spring can be made from several leaves stacked on top of each other in several layers, often with progressively shorter leaves. Leaf springs can serve locating and to some extent damping as well as springing functions.

A leaf spring can either be attached directly to the frame at both ends or attached directly at one end, usually the front, with the other end attached through a shackle, a short swinging arm. The shackle takes up the tendency of the leaf spring to elongate when compressed and thus makes for softer springiness.

History

There were a variety of leaf springs, usually employing the word "elliptical". "Elliptical" or "full elliptical" leaf springs referred to two circular arcs linked at their tips. This was joined to the frame at the top center of the upper arc, the bottom center was joined to the "live" suspension components, such as a solid front axle. Additional suspension components, such as trailing arms, would be needed for this design, but not for "semi-elliptical" leaf springs as used in the Hotchkiss drive. The Hotchkiss drive is a system of Power transmission. It was the dominant form of power transmission for front-engine rear-drive cars in the 20th century That employed the lower arc, hence its name. "Quarter-elliptic" springs often had the thickest part of the stack of leaves stuck into the rear end of the side pieces of a short ladder frame, with the free end attached to the differential, as in the Austin Seven of the 1920s. As an example of non-elliptic leaf springs, the Ford Model T had multiple leaf springs over its differential that were curved in the shape of a yoke. As a substitute for dampers (shock absorbers), some manufacturers laid non-metallic sheets in between the metal leaves, such as wood.

Leaf springs were very common on automobiles, right up to the 1970s, when the move to front wheel drive, and more sophisticated suspension designs saw automobile manufacturers use superior coil springs instead. This article is about the Decade 1970-1979 For the Year 1970 see 1970. Front-wheel drive (or FF layout) is a form of engine / transmission layout used in Motor vehicles where the engine drives the front Wheels Suspension is the term given to the system of springs, Shock absorbers and linkages that connects a Vehicle to its Wheels Suspension The automotive industry is the industry involved in the design development manufacture marketing and sale of Motor vehicles In 2007 more than 73 million motor vehicles A spring is a flexible elastic object used to store mechanical Energy. U. S. passenger cars used leaf springs until 1989 where the Chrysler M platform was the final production vehicle marketed. The M-Bodies were Chrysler Corporation 's successor to the F-body Aspen/Volare. However, leaf springs are still used in heavy commercial vehicles such as vans and trucks, SUVs, and railway carriages. A van is a kind of vehicle used for Transporting goods or groups of people This article is about the semi-truck For the North American use of the word see Pickup truck. A sport utility vehicle ( SUV) is a generic marketing description for a rugged automotive vehicle similar to a Station wagon but built on a light-truck chassis A Railway coach &mdash also known especially in the UK, as a railway carriage &mdash is a passenger car designed for the conveyance of passengers 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 arms and a Panhard rod, thereby saving cost and weight in a simple live axle rear suspension. A trailing-arm suspension is an Automobile suspension design in which one or more arms (or "links" are connected between (and perpendicular to and forward A Panhard rod (also called Panhard bar or track bar) is a component of a car suspension system that provides lateral location of the A live axle is a type of Beam axle suspension system that uses the Driveshafts that transmit power to the wheels to connect the wheels laterally so that

A more modern implementation is the parabolic leaf spring. This design is characterised by fewer leaves whose thickness varies from centre to ends following a parabolic curve. In this design, inter-leaf friction is unwanted, and therefore there is only contact between the springs at the ends and at the centre where the axle is connected. Spacers prevent contact at other points. Aside from a weight saving, the main advantage of parabolic springs is their greater flexibility, which translates into vehicle ride quality that approaches that of coil springs. Ride quality refers to the degree of protection offered vehicle occupants from uneven elements in the Road surface or the Terrain if driving Off-road. There is a trade-off in the form of reduced load carrying capability, however.

See also

• Corvette leaf springs
• Coil spring