# US 4,400,336 A · Method of molding a hollow retainer in a foam article

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- Number: US 4,400,336 A
- Document ID: US4400336A
- Status: Granted
- Kind: A
- Application number: 06/314,251
- Filed: 1981-10-23
- Granted: 1983-08-23
- Earliest claimed: 1981-10-23
- Assignees: General Motors Corporation
- Inventors: Robert D. Thomas
- Web page: https://patentgrep.com/patent/US4400336A

## CPC

- B29C 33/0044: {for sealing off parts of inserts projecting into the mould cavity}
- B29C 33/14: against the mould wall
- B29C 44/1271: {the preformed parts being partially covered}
- B29C 44/14: the preformed part being a lining {(B29C44/1209 takes precedence)}
- B29K 2105/04: cellular or porous
- B29L 2031/3014: {Door linings}
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

A method by which a previously molded hollow plastic retainer having an open end portion necessitated by the need to withdraw a mold core therefrom may be embedded in a molded trim article with the open end beneath the surface and yet the molding material is prevented from flowing through the open end portion and filling the hollow of the retainer. The method comprises the steps of loading the molded plastic retainer between a first mold portion having a wall extending into closure of the opening in the molded plastic retainer and a second mold portion spaced from the first mold portion to define the desired confines of the molded trim article in which the plastic retainer is to be embedded; injecting the molding material for the molding of the molded trim article into the space between the first and second mold portions; and separating the first and second mold portions after the curing of the molding material whereby the plastic retainer is embedded in the molded trim article without the flow of molding material through the open end portion to fill the desired hollow in the molded plastic retainer.

## Claims

### Claim 1

A method by which a previously molded hollow plastic retainer having a top wall with an opening adapted to receive the enlarged head of a fastener and side wall structure defining an open end portion, necessitated by the need to withdraw therefrom a mold core used in previously molding the hollow plastic retainer, may be embedded in a molded trim article with the opening at the surface of the trim article and with the side wall structure and the open end portion defined thereby beneath the surface and yet the molding material is prevented from flowing through the open end portion and filling the hollow provided for receiving the head of the fastener, said method comprising the steps of:
loading the molded plastic retainer between a first mold portion having both a projection to extend into the opening to locate the retainer in the mold with the opening of the retainer at the surface of the trim article and a wall extending generally perpendicularly from the first mold portion into sealing contact with the side wall structure defining the open end portion of the molded plastic retainer and a second mold portion spaced from the first mold portion to define the desired confines of the molded trim article in which the plastic retainer is to be embedded;
injecting the molding material for the molding of the molded trim article into the space between the first and second mold portions; and
separating the first and second mold portions after the curing of the molding material whereby the plastic retainer is embedded in the molded trim article without the flow of molding material through the open end portion to fill the desired hollow for receiving the head of the fastener in the molded plastic retainer.