欧美黑人3p-欧美黑大硬粗免费视频-欧美黑大粗-欧美黑粗特黄午夜大片-欧美黑白配性xxxxx-欧美黑b

Disc brake History

 

Early experiments

Development of disc brakes began in England in the 1890s.

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. 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 poor state of the roads at this time, no more than dusty, rough tracks, meant the copper wore quickly making the system impractical.

The American Crosley Hot Shot is often given credit for the first production disc brakes. For six months in 1950, Crosley built a car with these brakes, then returned to drum brakes. Lack of sufficient research caused reliability problems, such as sticking and corrosion, especially in regions using salt on winter roads. Drum brake conversions for Hot Shots were quite popular. The Crosley disc was a Goodyear development, a caliper type with ventilated disc, originally designed for aircraft applications.

Chrysler developed a unique braking system, offered from 1949 to 1953. Instead of the disc with caliper squeezing on it, this system used twin expanding discs that rubbed against the inner surface of a cast-iron brake drum, which doubled as the brake housing. The discs spread apart to create friction against the inner drum surface through the action of standard wheel cylinders. Because of the expense, the brakes were only standard on the Chrysler Crown and the Town and Country Newport in 1950. They were optional, however, on other Chryslers, priced around $400, at a time when an entire Crosley Hot Shot retailed for $935. This four-wheel disc brake system was built by Auto Specialties Manufacturing Company (Ausco) of St. Joseph, Michigan, under patents of inventor H.L. Lambert, and was first tested on a 1939 Plymouth. Chrysler discs were "self energizing," in that some of the braking energy itself contributed to the braking effort. This was accomplished by small balls set into oval holes leading to the brake surface.When the disc made initial contact with the friction surface, the balls would be forced up the holes forcing the discs further apart and augmenting the braking energy. This made for lighter braking pressure than with calipers, avoided brake fade, promoted cooler running, and provided one-third more friction surface than standard Chrysler twelve-inch drums. Today's owners consider the Ausco-Lambert very reliable and powerful, but admit its grabbiness and sensitivity.

Racing breakthrough

Reliable caliper-type disc brakes first appeared in 1953 on the Jaguar C-Type racing car. These brakes helped the company to win the 1953 24 Hours of Le Mans,developed in the UK by Dunlop. That same year, the aluminum bodied Austin-Healey 100S, of which 50 were made, was the first car sold to the public to have disc brakes, fitted to all 4 wheels.

Mass production

The first mass production use of the modern disc brake was in 1955, on the Citroën DS, which featured caliper-type front disc brakes among its many innovations. These discs were mounted inboard near the transmission, and were powered by the vehicle's central hydraulic system. This model went on to sell 1.5 million units over 20 years with the same brake setup.

The Jensen 541, with four-wheel disc brakes, followed in 1956.

Disc brakes were most popular on sports cars when they were first introduced, since these vehicles are more demanding about brake performance. Discs have now become the more common form in most passenger vehicles, although many (particularly light weight vehicles) use drum brakes on the rear wheels to keep costs and weight down as well as to simplify the provisions for a parking brake. As the front brakes perform most of the braking effort, this can be a reasonable compromise.

Many early implementations for automobiles located the brakes on the inboard side of the driveshaft, near the differential, while most brakes today are located inside the wheels. An inboard location reduces the unsprung weight and eliminates a source of heat transfer to the tires.

Historically, brake discs were manufactured throughout the world with a strong concentration in Europe and America. Between 1989 and 2005, manufacturing of brake discs migrated predominantly to China.

2016-09-27 23:56:04
主站蜘蛛池模板: 天天看天天摸天天操 | 国产在线欧美日韩精品一区二区 | 亚洲国产欧美在线人成 | 亚洲国产日韩女人aaaaaa毛片在线 | 香蕉视频免费在线观看 | 久视频在线| 精品国产乱码一区二区三区麻豆 | 亚洲一区二区影院 | 国产日韩欧美在线播放 | 欧美韩国日本一区 | 国产精品第一 | 国产一区二区视频在线 | 日本三级中文字幕 | 久久精品国产99久久99久久久 | 综合毛片 | 性欧美精品久久久久久久 | 91青青国产在线观看免费 | 亚洲欧美一区二区三区在线观看 | 国产免费又粗又猛又爽视频国产 | 日本免费爱爱视频 | 黄的日本免费大片 | 亚洲激情在线视频 | 97公开免费视频 | 内地毛片 | 在线免费观看欧美 | 午夜影院免费观看视频 | 日本一级网站 | 亚洲刺激视频 | 特黄女一级毛片 | 外国毛片 | a级高清观看视频在线看 | 日韩黄色大片免费看 | 国产亚洲一区二区三区在线 | 三级带黄色 | 欧美在线一级精品 | 国内精品一区视频在线播放 | 爱操综合 | 成人免费黄色网 | 在线不欧美 | 国产精品第| 不卡一区二区在线观看 |