The American Crosley Hot Shot had four wheel disc brakes in 19, but these quickly proved troublesome and were removed. The German Tiger I heavy tank, was introduced in 1942 with a 55 cm Argus-Werke disc on each drive shaft. Argus supplied wheels fitted with disc brakes e.g. Īt Germany's Argus Motoren, Hermann Klaue (1912-2001) had patented disc brakes in 1940. In Britain, the Daimler Company used disc brakes on its Daimler Armoured Car of 1939, the disc brakes, made by the Girling company, were necessary because in that four-wheel drive (4x4) vehicle the epicyclic final drive was in the wheel hubs and therefore left no room for conventional hub-mounted drum brakes. By the early 1950s, disc brakes were being regularly applied to new passenger rolling stock. In the US, the Budd Company introduced disc brakes on the General Pershing Zephyr for the Burlington Railroad in 1938. Successful application began on railroad streamliner passenger trains and in airplanes and tanks before and during World War II. Front and rear brakes of this type were fitted to the machine on which Tom Sheard rode to victory in the 1923 Senior TT. Patented by the British Motorcycle & Cycle-Car Research Association, Douglas described the device as a "novel wedge brake" working on a "bevelled hub flange", the brake was operated by a Bowden cable. In 1921, the Douglas motorcycle company introduced a form of disc brake on the front wheel of their overhead-valve sports models. The poor state of the roads at this time, no more than dusty, rough tracks, meant that the copper wore quickly making the system impractical. However, the limited choice of metals in this period meant that he had to use copper as the braking medium acting on the disc. The first caliper-type automobile disc brake was patented by Frederick William Lanchester in his Birmingham factory in 1902 and used successfully on Lanchester cars. History Early experiments ĭevelopment of disc brakes began in England in the 1890s. Friction causes the disc and attached wheel to slow or stop. To slow down the wheel, friction material in the form of brake pads, mounted on the brake caliper, is forced mechanically, hydraulically, pneumatically, or electromagnetically against both sides of the disc. This is connected to the wheel and/or the axle. The disc is usually made of cast iron, but may in some cases be made of composites such as reinforced carbon–carbon or ceramic matrix composites. Drums are also prone to "bell mouthing" and trap worn lining material within the assembly, both causes of various braking problems.
PAD SYSTEM PATTERN DRIVER
This tends to give the driver better "feel" and helps to avoid impending lockup. By contrast, a disc brake has no self-servo effect and its braking force is always proportional to the pressure placed on the brake pad by the braking system via any brake servo, braking pedal, or lever. Most drum brake designs have at least one leading shoe, which gives a servo-effect. Disc brakes also recover more quickly from immersion (wet brakes are less effective than dry ones). As a consequence discs are less prone to the brake fade caused when brake components overheat. Ĭompared to drum brakes, disc brakes offer better stopping performance because the disc is more readily cooled. Mass production began with the abortive 1949 Crosley experiment, with sustained mass production beginning in 1955 Citroën DS. The Jaguar racing team won, using disc brake equipped cars, with much of the credit being given to the brakes' superior performance over rivals equipped with drum brakes. In the 1950s, there was a critical demonstration of superiority at the 1953 24 Hours of Le Mans race, which required braking from high speeds several times per lap. After the war, technological progress began to arrive in 1949, with caliper-type four wheel disc brakes on the Crosley line, and a Chrysler non-caliper type. Successful application began in airplanes before World War II, and even the German Tiger tank was fitted with discs in 1942.
Other designs were not practical or widely available in cars for another 60 years. In 1902, the Lanchester Motor Company designed brakes that looked and operated in a similar way to a modern disc-brake system even though the disc was thin and a cable activated the brake pad. Development of disc-type brakes began in England in the 1890s.
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