This "public domain" article is available to anyone with an attorney, and has been for more than 20 years. "ROCKER ARM HAVING PERPENDICULAR GEOMETRY AT VALVE MID-LIFT" is OBVIOUS. To this day, it resides as the only Patent ever issued on a "concept" of geometrical precision for a roller tip rocker arm, whereby the pushrod's geometry was "balanced" simultaneously with the roller tip (valve's) geometry. Even before 1980, when this was filed, Jim Miller was using dimensional reference points on the rocker body to provide a formula to adjust "installed geometry" accurately, as depicted by "A" and "B" in the adjusting screw slot. (The number 1 "shaft" rocker manufacturer was still fitting big block Chevrolet rockers to small block Chevy heads, in pursuit of better geometry, incorrectly believed as being defined by a longer rocker.)