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: 色综合亚洲一区二区小说 | 在线国产三级 | 日韩精品综合 | 久久日本精品国产精品白 | 在线色视频网站 | 日韩一区二区三区在线观看 | 国产乱肥老妇精品视频 | 草草在线视频 | 美女一级片视频 | 看黄网站在线 | 亚洲一区二区免费在线观看 | 免费无尽xxx视频 | 俄罗斯精品三级在线观看 | 免费日本在线 | 久色视频在线 | 毛片在线播放网站 | 成人一级毛片 | 一二三四在线播放视频国语高清观看免费 | 久操视频免费看 | 国产精品亚洲一区二区三区久久 | 国产成人a福利在线观看 | 亚洲美女福利视频 | 一道精品视频一区二区三区图片 | 性生活毛片 | 午夜毛片网站 | 亚洲区视频在线观看 | 国产精品亚洲一区二区三区在线播放 | 成人深夜视频在线观看 | 国产主播在线播放 | 久久久久国产一级毛片高清板 | 欧美色欧美亚洲另类二区 | 四虎网站最新网址 | 国产成人精品高清在线观看99 | 国产三级在线免费 | 中文字幕一级毛片视频 | 亚洲va欧美va国产va天堂影 | 男女超爽视频免费播放在线观看 | 亚洲精品在线观看91 | 视频一区色眯眯视频在线 | 欧美日韩xxx| 久久草视频 |