Starter Shift Lever Design for Abrasion Resistance

The invention uses composite construction by combining resin lever bodies with metal (specifically brass or bronze) insert portions. The metal insert portions are embedded in the resin lever bodies at the clutch outer engagement areas, creating a composite structure that leverages the low cost and deformability of resin while incorporating the high abrasion resistance and strength of metal materials at critical wear points.

The invention applies local quality by making the annular plate directionally neutral (symmetrical in both directions) rather than directionally dependent. This allows the annular plate to be assembled in either orientation without requiring precise directional alignment, easing assembly while the metal construction provides the necessary durability and resistance to deformation and fracture.

The invention makes the annular plate universal by making it directionally neutral, allowing it to function equally well in both pushing out and return directions. The grooves are formed on both sides of the annular plate, ensuring that grease retention and abrasion protection are provided regardless of which side is facing which direction, eliminating the directional dependency and associated abrasion problems on the return side.

The invention applies curvature by forming rounded corners at the four corners of the shift pieces instead of sharp rectangular corners. This curvature eliminates stress concentration points that would otherwise be present at the sharp corners, preventing crack initiation and propagation while maintaining the simple overall rectangular shape and design for the shift pieces.