How power steering invention transformed twentieth-century society

Power Steering

After years of work on improving general steering apparati as a Pierce-Arrow truck engineer, Francis W. Davis developed and improved the first commercial examples of power steering systems (Watson 2006). Davis patented power steering in 1932. He was working for General Motors' Cadillac branch (Watson 2006). Prior to acquiring the patent, power steering systems were used mainly on large-scale manufacturing vehicles. Power steering made turning the steering wheels on fully loaded trucks tremendously easier, thereby increasing worker productivity and manufacturing profitability. Watson (2006) notes that one coal company driver "could turn the wheel on his fully loaded truck with two fingers."

Power steering has dramatically changed society in the twentieth century just as the computer mouse has: by improving ease of consumer access to complex machines. Just as the mouse is an input device for computers, power steering is an input device for automobiles. Both the mouse and power steering enable the end-user to customize his or her experience and enjoy using technology. As power steering became more widely used on commercial vehicles, a greater number of consumers found driving to be an enjoyable activity. The Chrysler Corporation first put a hydraulic steering system called Hydraguide. Similar to Davis' power steering on a commercial automobile in 1951, Hydraguide effectively bypassed the original patent while being based on the same basic power steering principles. The French manufacturer Citro n also developed its own hydraulic steering system known as "Direction a rappel asservi," or DIRAVI. Power steering soon became commonplace on manufactured commercial cars and was ubiquitous by the end of the twentieth century.

Power steering is based on hydraulics and so fluid is necessary to power the basic rack-and-pinion steering system. A rotary valve is attached to steering gear driven by a pump, belt and pulley; the entire system is also composed of "retractable vanes" spinning inside an "oval chamber," (Nice nd). The hydraulic fluid levels vary depending on engine speed, regulating pressure and providing a safe and optimally comfortable driving experience. Power steering is usually engaged only when the driver must exert extra force or torque such as during a turn. Otherwise, during long stretches of straight roads, power steering is not necessary.

Still used on almost all late twentieth-century commercial automobiles, power steering systems have not changed substantially in their basic principles since they were first developed as hydraulic systems in the middle of the twentieth century. Recently power steering systems have improved dramatically. Nice (nd) notes that power steering does consume fuel and so automobile engineers have been striving to make the hydraulic systems more efficient. Electronic controls would "eliminate the mechanical connection between the steering wheel and the steering," (Nice nd). Essentially, an electronic power steering system would feel more like a computer gaming wheel than a traditional car wheel (Nice nd). General Motor's Hy-Wire system is an emerging example of electronic "drive by wire" power steering systems (Nice nd).