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: 一级毛片大全免费播放 | 久久一区二区三区免费播放 | 国产在线精品成人一区二区三区 | 亚洲成在人线av | 在线日韩亚洲 | 三级网站免费 | 一区二区三区四区国产精品 | 日韩国产有码在线观看视频 | 美女毛片在线 | 色拍拍在线精品视频在线观看 | 国产精品亚洲欧美日韩一区在线 | 久久精品一区二区三区资源网 | 日韩亚洲欧美性感视频影片免费看 | 久操福利在线 | 欧美在线观看成人高清视频 | 亚洲视频在线一区二区三区 | 国产精品高清在线观看 | 日本视频在线播放 | 欧美日韩免费在线观看 | 韩国三级带日本三级带黄 | 黄页网站在线观看 | 亚洲无线码在线一区观看 | 欧美成人午夜免费完成 | 国产女人18毛片水真多18精品 | 国产精品欧美在线 | 国产精品手机视频一区二区 | 日本高清视频免费看 | 一个人看的免费高清视频日本 | 一级视频在线观看免费 | 国产精品久久久久久久免费大片 | 亚洲视频日韩 | 日韩一区二区三区免费视频 | 精品国产一区在线观看 | 青草青草久热精品观看 | 一机毛片 | 亚洲欧美一区二区视频 | 日韩一级片在线观看 | 亚洲精品美女一区二区三区乱码 | 国产日韩欧美在线 | 欧美成人毛片一级在线 | 国产精品天天干 |