Patent ID: 8899302

Claim:
A valve for permitting gas to escape from a mold cavity when the mold cavity is injected with a melt, the valve comprising: an inlet coupled to the mold cavity; an outlet for venting gas from the mold cavity; a closure oriented substantially perpendicularly to the inlet and movable between open and closed positions for closing off the outlet, the closure having a central axis perpendicular to the inlet, the closure having a concave surface the valve having a first wall which is curved to redirect the melt passing through the inlet by about 90° and maintain a laminar flow in the melt and direct the melt to travel coaxially toward the closure so as to impinge substantially coaxially upon the closure on the concave surface and transfer a majority of the momentum of the melt to the closure; the first wall being configured to direct the melt to impinge directly on to the closure member by applying a pressure gradient to the melt so that the melt maintains its momentum as it passes against the first wall and impinges on to the closure, and wherein the valve further comprises a chamber coupled to and adjacent the inlet, the closure having a concave surface projecting into the chamber when the closure is in its open position, the first wall having a terminal edge, the first wall being curved sufficiently to point the terminal edge toward the axis of the closure and direct the melt to impinge directly on to the concave surface of the closure.