Abstract: In general, the three-plate mold was only suitable for a point gate, and the artificial removal should be conducted for the freezing resin in the gating system of the two-plate mold with an edge gate. This paper reported a design of a three-plate mold with an edge gate for the partial gear on intermittent wipers. In this mold, the gate was designed as a short edge gate with a length of 2 mm and a tilt angle of 30 °. The mold opening was successfully performed in a correct order and distance through a design of the complex limiting mechanism with big and small pull rods. This mold design extends the applicable range of the three-plate mold and realizes the automatic separation of injection-mold parts with the freezing resin in the gating system, thus improving the production efficiency and saving the labor cost.