A variable-pitch racked bar

摘要

A variable-pitch racked bar has a row of rack teeth with a middle fixed pitch region and two end fixed pitch regions. A variable-pitch region is interposed between the middle fixed pitch region and each of the end fixed pitch regions. In the variable-pitch region, the pitch increases from the fixed, small-pitch middle region toward the fixed, large-pitch end regions. In the variable-pitch racked bar, the effective meshing width continuously decreases from the middle of the row of rack teeth toward both ends thereof.