US 4,755,339 A · Method and apparatus for making molded window gasket

Abstract

An improved window gasket assembly and the apparatus and associated method for reaction injection molding such as assemblies, as well as other molded articles, are disclosed. The gasket is preferably integrally molded from an elastomeric material such as urethane onto a substantially transparent window panel. The gasket and window assembly can then be mounted and secured directly to vehicle body panel opening, for example, with adhesives, thereby eliminating the need for discrete mechanical fasteners. In a preferred embodiment of the invention, an improved aftermixer and gating apparatus includes a mixing body in which a flowable multi-constituent molding material is separated into a number of generally serpentine mixing passageways and reunited in a common mixing cavity before being conveyed through a fan-gate passageway to the mold cavity. Adjustment means is provided for selectively altering the size of the mixing cavity and its inlet openings in order to selectively alter the back-pressure exerted on the material flowing therethrough, thereby enhancing the mixing of the molding material constituents. An improved mold apparatus is also preferably employed and includes elongated elastomeric members along the preferable edge of the mold cavity for supportingly engaging the mold members and substantially minimizing or preventing flashing of the molding material therefrom.

Claims11

Dependent claims

A method of molding a window gasket member onto an edge portion of a glass window panel in a mold cavity of a reaction injection molding system, said gasket member being composed of a multi-constituent urethane material, said method comprising:

positioning said glass window panel in a mold apparatus defining said mold cavity with said edge portion extending into said mold cavity and closing said mold apparatus;
injecting the constituents of said urethane material under pressure into a first mixing device at a predetermined flow rate;
injecting said pressurized urethane material into an aftermixer device;
separating said urethane material into at least a pair of generally serpentine flow streams in said aftermixer device and then reuniting said flow streams in a mixing cavity in said aftermixer device;
and
conveying said urethane material through a gating device from said mixing cavity into said mold cavity;
removing said glass window panel from said mold cavity with said gasket member thereon after said urethane material has at least partially cured in said mold cavity.

4 more elements

A reaction injection molding system for molding window gaskets or the like onto a glass window panel, from a multi-constituent urethane material in a mold cavity, said system comprising in combination:

a source of the constituents of said urethane material in a pressurized flowable state;
means for receiving and intermixing said urethane material constituents from said source and for conveying said intermixed multi-constituent urethane material to said mold cavity at a predetermined pressure;
a mold apparatus including at least a first mold member and a second mold member mutually engageable with one another and defining said mold cavity therebetween, at least one of said mold members including at least one flexible elastomeric member thereon generally adjacent an edge of said mold cavity and extending generally around the periphery thereof, said elastomeric member supportingly engaging the other of said mold members and being adapted to substantially prevent flashing of said urethane material out of said mold cavity, said mold cavity being adapted to receive a glass window panel inserted therein prior to the introduction of said multi-constituent urethane material into said mold cavity, said glass window panel being sealingly supported between a pair of said flexible elastomeric members.

Dependencies are inferred from the claim text.

Method and apparatus for making molded window gasket

Life of this patent

Method and apparatus for making molded window gasket

Life of this patent

Abstract

Claims11