Patent ID: 8470233

Claim:
A method for producing a lens cover, the method comprising: preparing a metal mold for molding a lens cover including a lens sealing portion at a peripheral edge of the lens cover, the metal mold including a stationary mold, a movable mold for defining a main cavity for molding a lens cover together with the stationary mold, and a slidable mold disposed between the stationary mold and the movable mold, the slidable mold configured to slidingly move into a space between the stationary mold and the movable mold, the slidable mold having a projection portion projected into a cavity for molding the lens sealing portion, wherein the projection portion of the slidable mold is formed along a parting line between the stationary mold and the movable mold; the lens sealing portion is composed of a thick wall portion at its tip to be jointed to a housing of a lighting unit and a thinned portion which is thinner than the thick wall portion, and is continued from the thick wall portion and connected to the peripheral edge of the lens cover; the cavity for molding the lens sealing portion includes a first cavity defined by the stationary mold and for forming the thick wall portion and a second cavity defined by the stationary mold and the projection portion of the slidable mold and for forming the thinned portion; the stationary mold has an inner surface for defining the first cavity with no stepped portion; the slidable mold and the movable mold form an intermediate inner surface with a stepped portion for defining an intermediate part of the first and second cavities; and the projection portion of the slidable mold has a dimension which defines the second cavity and corresponds to a length of the thinned portion and which is 60% or less of a length of the lens sealing portion; clamping the stationary mold, the movable mold, and the slidable mold; injecting a molten resin into the main cavity for molding a lens cover including the lens sealing portion so that the molten resin flows in a uniform layer-like state without any flow deviation and without forming an unfilled portion; slidingly moving the slidable mold; opening the movable mold from the stationary mold; and releasing a molded product from the metal mold.