Rocker Arm - History

History

Jonathan "Rundle" Bacon created them in the 19th century, rocker arms have been made with and without "rundle" roller tips that depress upon the valve, as well as many lightweight and high strength alloys and bearing configurations for the fulcrum, striving to increase the RPM limits higher and higher for high performance applications, eventually lending the benefits of these race bred technologies to more high-end production vehicles. Even the design aspects of the rocker arm's geometry has been studied and changed to maximize the cam information exchange to the valve which the rocker arm imposes, as set forth by the Miller US Patent, #4,365,785, issued to James Miller on December 28, 1982, often referred to as the MID-LIFT Patent. Previously, the specific pivot points with rocker arm design was based on older and less efficient theories of over-arcing motion which increased wear on valve tips, valve guides and other valve train components, besides diluting the effective cam lobe information as it was transferred through the rocker arm's motion to the valve. Jim Miller's MID-LIFT Patent set a new standard of rocker arm geometrical precision which defined and duplicated each engine's specific push-rod to valve attack angles, then designing the rocker's pivot points so that an exact perpendicular relationship on both sides of the rocker arm was attained: with the valve and the pushrod, when the valve was at its "mid-lift" point of motion.

Truck engines (mostly diesel) use stronger and stiffer rocker arms made of cast iron (usually ductile), or forged carbon steel.

Read more about this topic:  Rocker Arm

Famous quotes containing the word history:

    It gives me the greatest pleasure to say, as I do from the bottom of my heart, that never in the history of the country, in any crisis and under any conditions, have our Jewish fellow citizens failed to live up to the highest standards of citizenship and patriotism.
    William Howard Taft (1857–1930)

    Free from public debt, at peace with all the world, and with no complicated interests to consult in our intercourse with foreign powers, the present may be hailed as the epoch in our history the most favorable for the settlement of those principles in our domestic policy which shall be best calculated to give stability to our Republic and secure the blessings of freedom to our citizens.
    Andrew Jackson (1767–1845)

    There is nothing truer than myth: history, in its attempt to “realize” myth, distorts it, stops halfway; when history claims to have “succeeded” this is nothing but humbug and mystification. Everything we dream is “realizable.” Reality does not have to be: it is simply what it is.
    Eugène Ionesco (b. 1912)