Adjustable shims for mold seals

Abstract

An adjustable sealing system for use in a molding apparatus is disclosed. The molding apparatus is used for applying a coating of polymeric material to the surface of a shell. The molding apparatus includes a molding surface and a seal groove adapted for retaining a seal. The molding apparatus is capable of receiving a shell and forming a molding cavity between a surface of a shell and the molding surface. The seal establishes sealed contact between the shell and the molding surface when the molding apparatus is closed. The adjustable sealing system includes a seal for insertion and retention in a seal groove of the molding apparatus, so that a portion of the seal extends from the seal groove to a selected height when the molding apparatus is open. A seal height adjustment means is disposed under the seal in the seal groove. The seal height adjustment means is capable of adjusting the height of the seal above the seal groove to correspond to a particular contour of a shell being molded. The shell establishes contact with the seal forming a sealed molding cavity between the shell and the receptacle's molding surface. The seal's height adjustment means may include a shaped polymeric wooden, metallic, or plastic shims; threadably adjustable shims; selectively sized ball bearings for placement between the shims; or a tubular expandable shim which may be inflated.