| 摘要 |
An injection mold cavity is sealed at the mold parting line using a highly exact, narrow annular gap or clearance which restricts flash through of the molten plastic. The seal is designed for molds having a rotatable pin and comprises a fixed seating ring which seats with the mold cavity element, and a journable seal ring having a precisely machined seal face which is narrowly spaced from the lip of the mold cavity and defines the gap dimension with the assistance of the seating ring. The rings float at a unit against a resilient component which controls the seating pressure of the assembly independently of the clamping force of the mold. The foregoing components are unitized within a clamp ring under a preload compressive force with the critical gap dimension precisely built into the unit. Variable compressive loading of the seal assembly in the injection mold is counteracted by the resilient component and floating motion of the seal and seating rings whereby highly exact preciseness can be obtained in the critical gap dimension over prolonged operating periods. |
