Patent ID: 6929464

Claim:
An injection mold comprising: a first mold half and a second mold half for moving relative to each other between an open position and a closed position, wherein the first and the second mold half define a molding cavity in which a molding material used for molding a product is filled at the closed position; and a pin that selectively reaches the molding cavity, the pin including a sleeve being provided with a cylinder portion and a box-shaped flange portion provided on a lower edge of the cylinder portion, wherein a passage hole is formed through the cylinder portion with an opened upper end while a stepped portion, an enlarged hollow portion, and an exhaust hole opened to the enlarged hollow portion are provided in the flange portion, the enlarged hollow portion communicating with a lower end of the passage hole via the stepped portion engaged therebetween; a valve structure having a rod-shaped valve portion being slidably arranged in the passage hole of the sleeve with a gas passageway interposed therebetween, gas in the molding cavity being exhausted through the gas passageway; and a collar portion connected with the valve portion, the collar portion being movably arranged in the enlarged hollow portion of the sleeve, wherein the gas passageway is selectively opened or closed by the valve structure that moves between a top dead point and a bottom dead point, the top dead point being where the collar portion is stopped by the stepped portion; and a biasing means for biasing the valve structure toward the top dead point.