Dubonnet suspension

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Alfa Romeo P3 Tipo B with Dubonnet front suspension Alfa Romeo P3 Tipo B Scuderia Ferrari.jpg
Alfa Romeo P3 Tipo B with Dubonnet front suspension

Dubonnet suspension was a system of leading arm independent front suspension and steering popular mainly in the 1930s and 1940s. Not very durable unless exactingly maintained, it was soon replaced by other designs. It consisted of a rigidly mounted axle beam from which the sprung steering and suspension arms pivoted around kingpins mounted on the ends of the axle. The wheels themselves were mounted onto stub axles, suspended by self-contained suspension units outboard of the kingpins. The system featured an encased coil spring and shock absorber, which sealed in the oil needed to lubricate and protect the suspension parts. This was also the weakness of the layout, as any leaks would have negative effects on ride and durability.

Front right suspension unit (forward direction to the upper left) Dubonnet-Federung.JPG
Front right suspension unit (forward direction to the upper left)

One advantage for a comfortable ride was the reduction in unsprung weight, as the kingpins and steering gear were inboard of the suspension, and not thus counted as sprung mass. This in turn led to 'synchronous' behaviour in many cars with this suspension, where the natural frequency of the front wheel suspension now, unusually for the time, matched that of the rear suspension and their solid driving axle. [lower-roman 1] The mass of the driving axle was greater but with the now softer springs of the lightweight front suspension, [lower-roman 2] their frequencies became comparable. This was a feature of Opel patents and advertising in the 1930s.

Dubonnet's own Hispano-Suiza H6B Dubonnet Xenia Hispano-SuizaH6CXenia.jpg
Dubonnet's own Hispano-Suiza H6B Dubonnet Xenia

The system was invented by French engineer and designer André Dubonnet [1] [2] (heir to the Dubonnet vermouth fortune), and built into his Hispano-Suiza based special of 1933. [3] He sold it to General Motors who adapted it as their "Knee-action ride", [4] but the system was also used by many others including Fiat, Alfa Romeo, Simca, and, possibly in its last incarnation, the 1953 Iso Isetta which carried forward to the 1955 BMW Isetta, the 1957 BMW 600 and the 1959 BMW 700. [5]

The General Motors connection led to one of the suspension's most numerous uses, with a return to Europe for the pre-war Vauxhall Twelve and Vauxhall Fourteen from 1935 to 1938. [6] The post-war Vauxhall Velox of 1949 reintroduced a similar leading arm suspension which is widely described as 'Dubonnet' suspension. [7] However this suspension used torsion bars rather than coil springs and so Vauxhall themselves denied that this was the 'true' Dubonnet. [6]

Related Research Articles

<span class="mw-page-title-main">Unsprung mass</span> Portion of a vehicle not supported by its suspension system

The unsprung mass of a vehicle is the mass of the suspension, wheels or tracks, and other components directly connected to them. This contrasts with the sprung mass supported by the suspension, which includes the body and other components within or attached to it. Components of the unsprung mass include the wheel axles, wheel bearings, wheel hubs, tires, and a portion of the weight of driveshafts, springs, shock absorbers, and suspension links. Brakes that are mounted inboard are part of a vehicle's sprung mass.

<span class="mw-page-title-main">Torsion bar suspension</span> Vehicle suspension that uses a torsion bar

A torsion bar suspension, also known as a torsion spring suspension, is any vehicle suspension that uses a torsion bar as its main weight-bearing spring. One end of a long metal bar is attached firmly to the vehicle chassis; the opposite end terminates in a lever, the torsion key, mounted perpendicular to the bar, that is attached to a suspension arm, a spindle, or the axle. Vertical motion of the wheel causes the bar to twist around its axis and is resisted by the bar's torsion resistance. The effective spring rate of the bar is determined by its length, cross section, shape, material, and manufacturing process.

<span class="mw-page-title-main">Car suspension</span> Suspension system for a vehicle

Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/handling and ride quality, which are at odds with each other. The tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the road or ground forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.

<span class="mw-page-title-main">Isetta</span> Motor vehicle

The Isetta is an Italian-designed microcar built under license in a number of different countries, including Argentina, Spain, Belgium, France, Brazil, Germany, and the United Kingdom. Because of its egg shape and bubble-like windows, it became known as a bubble car, a name also given to other similar vehicles.

<span class="mw-page-title-main">Independent suspension</span> Vehicle suspension in which each wheel is suspended independently

Independent suspension is any automobile suspension system that allows each wheel on the same axle to move vertically independently of the others. This is contrasted with a beam axle or deDion axle system in which the wheels are linked. "Independent" refers to the motion or path of movement of the wheels or suspension. It is common for the left and right sides of the suspension to be connected with anti-roll bars or other such mechanisms. The anti-roll bar ties the left and right suspension spring rates together but does not tie their motion together.

Automobile handling and vehicle handling are descriptions of the way a wheeled vehicle responds and reacts to the inputs of a driver, as well as how it moves along a track or road. It is commonly judged by how a vehicle performs particularly during cornering, acceleration, and braking as well as on the vehicle's directional stability when moving in steady state condition.

A swing axle is a simple type of independent suspension designed and patented by Edmund Rumpler in 1903. This was a revolutionary invention in automotive suspension, allowing driven (powered) wheels to follow uneven road surfaces independently, thus enabling the vehicle's wheels to maintain better road contact and holding; plus each wheel's reduced unsprung weight means their movements have less impact on the vehicle as a whole. The first automotive application was the Rumpler Tropfenwagen, later followed by the Mercedes 130H/150H/170H, the Standard Superior, the Volkswagen Beetle and its derivatives, the Chevrolet Corvair, and the roll-over prone M151 jeep amongst others.

<span class="mw-page-title-main">De Dion tube</span>

A de Dion tube is a form of non-independent automobile suspension. It is a considerable improvement over the swing axle, Hotchkiss drive, or live axle. Because it plays no part in transmitting power to the drive wheels, it is sometimes called a "dead axle".

<span class="mw-page-title-main">Sliding pillar suspension</span>

A sliding pillar suspension is a form of independent front suspension for light cars. The stub axle and wheel assembly are attached to a vertical pillar or kingpin which slides up and down through a bush or bushes which are attached to the vehicle chassis, usually as part of transverse outrigger assemblies, sometimes resembling a traditional beam axle, although fixed rigidly to the chassis. Steering movement is provided by allowing this same sliding pillar to also rotate.

<span class="mw-page-title-main">Fiat 130</span> Motor vehicle

The Fiat 130 is a large six cylinder executive car produced by Italian car manufacturer Fiat from 1969 to 1977. It was available as a 4-door saloon and as a 2-door coupé.

<span class="mw-page-title-main">Beam axle</span> Automobile mechanism

A beam axle, rigid axle or solid axle is a dependent suspension design in which a set of wheels is connected laterally by a single beam or shaft. Beam axles were once commonly used at the rear wheels of a vehicle, but historically they have also been used as front axles in four-wheel-drive vehicles. In most automobiles, beam axles have been replaced with front and rear independent suspensions.

Self-levelling refers to an automobile suspension system that maintains a constant ride height of the vehicle above the road, regardless of load.

A motorcycle's suspension serves a dual purpose: contributing to the vehicle's handling and braking, and providing safety and comfort by keeping the vehicle's passengers comfortably isolated from road noise, bumps and vibrations.

The following outline is provided as an overview of and topical guide to automobiles:

<span class="mw-page-title-main">Motorcycle fork</span> Component of motorized two-wheelers

A motorcycle fork connects a motorcycle's front wheel and axle to its frame, typically via a yoke, also known as a triple clamp, which consists of an upper yoke joined to a lower yoke via a steering stem, a shaft that runs through the steering head, creating the steering axis. Most forks incorporate the front suspension and front brake, and allow the front wheel to rotate about the steering axis so that the bike may be steered. Most handlebars attach to the top clamp in various ways, while clip-on handlebars clamp to the fork tubes, either just above or just below the upper triple clamp.

<span class="mw-page-title-main">Bicycle suspension</span> Bicycle part

Bicycle suspension is the system, or systems, used to suspend the rider and bicycle in order to insulate them from the roughness of the terrain. Bicycle suspension is used primarily on mountain bikes, but is also common on hybrid bicycles.

<span class="mw-page-title-main">Twist-beam rear suspension</span>

The twist-beam rear suspension is a type of automobile suspension based on a large H or C-shaped member. The front of the H attaches to the body via rubber bushings, and the rear of the H carries each stub-axle assembly, on each side of the car. The cross beam of the H holds the two trailing arms together, and provides the roll stiffness of the suspension, by twisting as the two trailing arms move vertically, relative to each other.

<span class="mw-page-title-main">Vauxhall 30-98</span> Motor vehicle

The Vauxhall 30–98 is a car manufactured by Vauxhall at Luton, Bedfordshire from 1913 to 1927. In its day, its best-known configuration was the Vauxhall Velox standard 4-seater with open tourer body. Vauxhall's own description was the 30–98 hp Vauxhall-Velox sporting car. The 30–98 is also known to enthusiasts by Vauxhall's chassis code E.

<span class="mw-page-title-main">Vauxhall 20-60</span> Motor vehicle

The Vauxhall 20-60 is a four or five-seater saloon, limousine, tourer or coupé-cabriolet manufactured by Vauxhall of Luton. It was announced on 28 September 1927 with a six-cylinder engine and a four-speed gearbox. A cautious move downmarket. "The first time any six-cylinder Vauxhall has been sold under £1000!" "British & Vauxhall". The initial 2.7-litre engine was enlarged to 3-litres after twelve months.

<span class="mw-page-title-main">Hispano-Suiza H6B Dubonnet Xenia</span> One-off luxury car manufactured by Spanish automobile manufacturer Hispano-Suiza

The Hispano-Suiza H6B Dubonnet Xenia is a one-off luxury car made by Spanish automobile manufacturer Hispano-Suiza for French pilot and racing car driver André Dubonnet in 1938. The car was built on the chassis of the Hispano-Suiza H6B, however it uses the larger, more powerful engine from the H6C and an entirely new body design by luxury coachbuilder Jacques Saoutchik.

References

  1. Almost all cars up to the 1950s used the Hotchkiss layout of front engine, and rear wheel drive through a solid rear axle.
  2. Assuming simple harmonic motion for a simplified mass-and-spring-system, with mass and spring stiffness , the natural frequency can be calculated as:
    Thus both a lower mass and softer springs together still give the same frequency.
  1. DE 644372,Dubonnet, André,"Lagerung für ein die Außenseite des Lenkrades von Kraftfahrzeugen abdeckendes Verkleidungsblech [Bearing for a covering panel covering the outside of the steering wheel of motor vehicles]",published 1937-04-29
  2. DE 697702,Dubonnet, André,"Radabfederung, insbesondere für Kraftfahrzeuge [Wheel suspension, especially for motor vehicles]",published 1940-10-21
  3. Rousseau, Jacques; Caron, Jean-Paul (1988). Guide de l'Automobile Française. Paris: Solar. p. 49. ISBN   2-263-01105-6.
  4. Gunnell, John. "A Good Steer: Shocks with wine name can make you whine when time comes to fix them". ChevyTalk.org. Archived from the original on 2011-03-15. Retrieved 2010-10-18.
  5. Trezel, Thierry (2010-09-03). "Dubonnet: Du spiritueux à l'automobile". mini.43. Retrieved 2010-10-18.
  6. 1 2 F. J. Woodbridge, Manager—Technical Division Service Department, Vauxhall Motors, Luton (May 1949). "Letters from Readers". Motor Sport . p. 36.{{cite magazine}}: CS1 maint: multiple names: authors list (link)
  7. WB (March 1949). "The New Vauxhall 'Velox'". Motor Sport . p. 19.