Other

Melea Limited

Milad Limited Partnership

Michael Ladney

Norman S Loren

William E Gordon

A gas injection apparatus for use with a gas assisted injection molding system. The gas injection apparatus includes a mold part defining an elongated bore communicating upstream with a source of gas and downstream with a mold cavity, and an elongated pin positioned in the bore and coacting with the bore to define a gas flow passage therebetween for movement of gas from the gas source to the mold cavity. The bore and pin include first, second and third corresponding portions. The pin and bore define an annular axial clearance in the first portion, a close fit with an axial linear passage in the second portion and an annular axial passage in the third portion. This arrangement ensures that the pin will remain concentric with respect to the bore so as to discourage entry of resin into the annular axial passage.

Gas injection apparatus for gas assisted injection molding system

A method and system are disclosed for locally introducing fluid, such as a gas, at a predetermined location into molten resin downstream from a resin injection aperture to form a hollow part. The gas is utilized at the localized area to distribute the molten resin, to eliminated molded in stress and to prevent formation of sink marks in the part during resin solidification. An overflow reservoir outside of the mold cavity is filled with the resin during resin injection and then the gas is introduced into the reservoir through a fluid aperture and into the part. The reservoir creates a cocoon of solidified material to act as a seal to prevent gas leakage. One hollow body formed by the method and system includes a substantially endless hollow body portion with a fluid opening for communicating the interior of the hollow body portion with the locally introduced fluid. The hollow body provides an internal gas manifold and means for greater structural integrity.

Method and system for localized fluid-assisted injection molding and

A system is disclosed for locally introducing fluid, such as a gas, at a predetermined location into molten resin downstream from a resin injection aperture to form a hollow part. The gas is utilized at the localized area to distribute the molten resin, to eliminated molded in stress and to prevent formation of sink marks in the part during resin solidification. An overflow reservoir outside of the mold cavity is filled with the resin during resin injection and then the gas is introduced into the reservoir through a fluid aperture and into the part. The reservoir creates a cocoon of solidified material to act as a seal to prevent gas leakage. One hollow body formed by the method and system includes a substantially endless hollow body portion with a fluid opening for communicating the interior of the hollow body portion with the locally introduced fluid. The hollow body provides an internal gas manifold and means for greater structural integrity.

System for localized fluid-assisted injection molding

A gas assisted injection molding method and apparatus wherein articles are produced by injecting molten resin into a mold cavity and then injecting a quantity of pressurized gas into the resin to fill out the mold cavity and form a hollow in the resin. Following the injection of the gas into the resin to form the hollow, gas is injected into the resin in the mold cavity at a second location. The gas injected at the second location may either form a separate hollow within the resin or may form a passage extending through the resin for communication with the hollow formed by the gas injected at the first location. The first location is preferably the resin injection location and the second location is preferably a location communicating directly with the mold cavity. Gas is vented from the article either at the first location, the second location, or both locations. The injection of the gas at the first and second locations, and the venting of the gas at the first and second locations, is separately controlled and regulated so that the gas may be injected at different pressures at the different locations, the gas may be injected or vented in a sequential manner at the different locations, and the gas may be vented from the first location until the pressure reaches a predetermined reduced level whereafter the gas may be vented from the second location to reduce the gas pressure to ambient.

Gas assisted injection molding

A unitary nozzle for use in a gas assisted injection molding process wherein the nozzle includes a central axial resin passageway, a land portion of the nozzle extends radially into the resin passageway proximate the downstream or discharge end of the nozzle to define a generally U-shaped resin passageway terminating in a U-shaped aperture at the nozzle tip, and a central gas passageway is provided on the central axis of the nozzle within the land portion and exiting the nozzle in a circular aperture embraced within the U-shaped resin aperture at the downstream end of the nozzle so that mixing of the resin and gas during the injection and venting processes is minimized and so that ingestion of resin into the gas passageway during the venting process is minimized.

Injection nozzle having a raised land portion

A method and apparatus for providing gas assistance in a resin injection molding process of the type in which hot resin is injected into a mold, gas is injected into the mold to displace a portion of the resin in the mold, the resin cools, the gas is vented, and the mold is opened to remove the molded part. The apparatus includes a high pressure gas storage system, a plurality of pressure control assemblies set at varying pressures and interposed between the high pressure gas storage system and the injection nozzle, and a control system which is operative to selectively communicate each of the pressure control assemblies with the injection nozzle so as to allow the delivery of gas at varying pressures to the mold to facilitate the creation of an individualized gas pressure profile to suit the particular molding requirement. The apparatus further includes a supplemental gas storage system including a plurality of gas storage containers interposed between the pressure control assemblies and the injection nozzle so that the supplemental gas storage system may be used in selective cooperation with the pressure control assemblies to provide further versatility with respect to the ability to tailor the pressure profile to the particular molding requirement.

An impact energy managing bumper structure having a configuration and component members that cooperatively provide, as a function of position along its length, predetermined levels of resilient opposition to deformation and displacement. A semirigid resilient fascia is spaced forwardly of the bumper structure, and the volume defined therebetween is filled with an integral skin urethane foam that is resiliently deformable and integrally bonded to both members.

Vehicle bumper

Method of injection molding with pressurized-fluid assist

A gas assisted injection molding apparatus of the type in which a supply of resin is introduced into a cavity in a mold at a resin injection location and a gas injection assembly is provided to introduce gas into the mold cavity at a gas injection location removed from the resin injection location to assist the resin in filling out the mold cavity. The gas injection assembly includes a bore in the mold communicating with the mold cavity, a pin having a size to fit slidably in the bore and including a central axial passage for delivery of gas into the mold cavity through the pin, a power cylinder assembly mounting the pin for movement between an advanced gas injection position in which the pin is positioned in the bore with its forward tip in communication with the mold cavity and a retracted position in which the mold cavity is vented through the bore, and an annular edge on the pin operative to remove obstructions with each forward movement of the pin from its retracted position to its advanced position.

Gas assisted injection molding apparatus

A method and apparatus for gas assisted injection molding. The apparatus includes a bulk storage container; a booster receiving the gas from the bulk storage container and operating to boost the pressure to a relatively high level for delivery to a high pressure storage container; a regulator receiving the gas from the high pressure storage container and reducing the gas pressure to a desired injection pressure; and a control system for injecting the gas into the mold, at the injection pressure as determined by the regulator, thereafter reducing the gas pressure within the mold to a hold pressure, thereafter maintaining the gas in the mold at the hold pressure, and thereafter venting the mold to atmosphere. The apparatus allows the performance of two distinct injection molding methods. In the first method, the regulated gas is injected directly into the mold, is held at the injection pressure during the fill out portion of the molding cycle, and is thereafter reduced to a hold pressure. In the second method, the gas from the regulator is stored in a plurality of fixed volume storage containers and is thereafter injected into the mold from a selected storage container so that, as the gas moves into the expanded volume of the mold during the fill out portion of the molding cycle, the injection pressure is caused to drop to a reduced pressure at which it is held for the duration of the cooling cycle whereafter the mold is vented and the mold opened.

An injection molding method and nozzle for use therein wherein first and second variable pressures are applied to a piston of a valve mechanism of the nozzle so that a differential fluid pressure on the piston causes a tip portion of the valve mechanism to alternately open and close. In this way, the tip portion communicates the flow of resin from a nozzle body of the nozzle to an injection aperture of a mold. Differential pressure on the piston prevents a fluid which distributes the molten resin over the interior surfaces of the mold from entering the flow path of the molten resin in the nozzle body. The fluid preferably is a gas, such as nitrogen. Preferably, the piston is mounted for reciprocating movement within the nozzle body and the first pressure is provided by the resin during resin injection and the second pressure is partially applied by the nitrogen gas. Preferably, the valve mechanism includes a counterbalance mechanism which is set to prevent fluid entry into the mold until the tip portion of the valve mechanism is closed. The resulting article is then cooled to a temperature below the softening point of the resin, the pressure is relieved within the article and the mold is opened to remove the article. The nozzle may also be utilized in making structural foam articles from a foamable resin. The pressure within the mold is relieved to permit foaming by the foamable resin after injection of the foamable resin.

Method of and apparatus for injection molding with pressurized-fluid

A vehicle spoiler includes a first rigid body part having an external surface contour, a second resiliently deformable foam body part having an external surface contour complementary to the first surface contour, and means for integrally securing the first and second body parts together. Preferably, the deformable foam body part is molded in situ on the rigid body part. A finishing groove extending between adjacent edges of the first external surface contour and the second external surface contour prevents recognition of differences between the materials and processes used to form the first and second body parts and prevents inconsistent transition between the body parts. A method for forming the spoiler includes fabrication of injection molded body shell parts bonded together by a foam material to form a rigid first body section. The rigid body section is then positioned within a molding cavity while foam material is introduced into the cavity and against engagement surfaces on the rigid body part.

Method of spoiler construction

A vehicle spoiler comprises a first rigid body part having an external surface contour, a second resiliently deformable foam body part having an external surface contour complementary to the first surface contour, and means for integrally securing the first and second body parts together. Preferably, the deformable foam body part is molded in situ on the rigid body part. A finishing groove extending between adjacent edges of the first external surface contour and the second external surface contour prevents recognition of differences between the materials and processes used to form the first and second body parts and prevents inconsistent transition between the body parts. A method for forming the spoiler includes fabrication of injection molded body shell parts bonded together by a foam material to form a rigid first body section. The rigid body section is then positioned within a molding cavity while foam material is introduced into the cavity and against engagement surfaces on the rigid body part.

Spoiler construction and method

A wheel cover mounting for plastic wheel covers comprising a mounting portion positioned in axial alignment with and spaced radially inward from a facing surface portion of a vehicle wheel. A spring wire retainer ring including radially outwardly extending projections spaced circumferentially around the ring in a substantially flat plane are received through circumferentially spaced openings in the mounting portion of the wheel cover. At least one, and preferably most if not all, of the openings are defined by guide walls circumferentially spaced apart a distance greater than the circumferential width of the projections in order to reduce frictional forces between the projections and the lugs and maximize the forces retaining the wheel cover on the wheel and in a fixed position with the wheel. The forces maintaining fixed positioning can be further increased by antirotational clips interposed between the wheel cover and a surface fixed for rotation with the wheel to resist relative rotational displacement of the wheel cover with respect to the wheel. Preferably, two spring clips including a resilient tang are disposed at diametrically opposed positions of the wheel cover with their tangs radially inclined in opposite rotational directions. The openings in the mounting portion near the spring clips are defined by guide walls spaced apart from each other a distance greater than the width of the projection extending through the opening so that the loading force of the spring clip does not affect the retaining force applied by the spring wire retainer.

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Warren, MI, United States of America

Norman S Loren