rocker arm

noun, Machinery

a rocking or oscillating arm or lever rotating with a moving shaft or pivoted on a stationary shaft.

Origin

1855-60

Examples from the web for rocker arm

The upper valve spring seat continued moving up the valve stem until it began to make contact with the neck of the rocker arm.
One broken spring piece had been bent by the rocker arm and had significantly dented the valve cover-nearly penetrating it.

British Dictionary definitions for rocker arm

noun

a lever that rocks about a pivot, esp a lever in an internal-combustion engine that transmits the motion of a pushrod or cam to a valve