Edward C Hunerberg

44735162, Sep 25, 1984

Jan 3, 1983

6/454942

Edward C. Hunerberg - Tecumseh MI

Hoover Universal, Inc. - Ann Arbor MI

B29D 2700

264 451

Method and apparatus for injection molding plastic articles having solid exterior surfaces and porous interior cores wherein a molten mixture of a chemically reactive foaming agent and a thermoplastic resin is injected into a mold so as to fill the mold cavity with unfoamed resin and form an outer solid skin on the molded article. Immediately prior to injection, an activator additive is introduced into the mixture, the additive reacting chemically with the foaming agent after a time delay of no more than a few seconds to provide for cellular expansion within the core of the molded article. The result is a molded body with a solid unfoamed skin which accurately relicates the surface of the mold and a cellular inner core.

51357038, Aug 4, 1992

May 16, 1991

7/701093

Edward C. Hunerberg - Tecumseh MI
Neil Daly - Jackson MI

Hoover Universal, Inc. - Plymouth MI

B29C 4500
B29C 4512
B29D 2200

264572

A combination plastic and gas injection nozzle assembly and method of operation in which the nozzle assembly includes a plastic resin passage, a closure member for the plastic resin passage, a gas flow passage, and a closure member for the gas flow passage all coaxial with respect to one another. Actuating cylinders are provided for moving both closure members between open and closed positions. The actuating cylinders being positioned coaxial with the other elements to eliminate off-set loading of the nozzle components. A sequential molding operation is disclosed in which a plurality of mold cavities defined by a single mold assembly are injected by one or more nozzles with plastic and a gas to form hollow spaces in the molded article. The cavities are injected with plastic one at a time to reduce the required mold clamping forces and enable independent control of plastic injection into each cavity. After partially filling each mold cavity, the nozzles are used to inject pressurized gas into the molten resin forcing the resin against the surface of the mold cavities and forming hollow spaces within the molded articles.

50546899, Oct 8, 1991

May 11, 1990

7/522190

Edward C. Hunerberg - Tecumseh MI
Neil Daly - Jackson MI

Hoover Universal, Inc. - Plymouth MI

B05B 712

239412

A combination plastic and gas injection nozzle assembly and method of operation in which the nozzle assembly includes a plastic resin passage, a closure member for the plastic resin passage, a gas flow passage, and a closure member for the gas flow passage all coaxial with respect to one another. Actuating cylinders are provided for moving both closure members between open and closed positions. The actuating cylinders being positioned coaxial with the other elements to eliminate off-set loading of the nozzle components. A sequential molding operation is disclosed in which a plurality of mold cavities defined by a single mold assembly are injected by one or more nozzles with plastic and a gas to form hollow spaces in the molded article. The cavities are injected with plastic one at a time to reduce the required mold clamping forces and enable independent control of plastic injection into each cavity. After partially filling each mold cavity, the nozzles are used to inject pressurized gas into the molten resin forcing the resin against the surface of the mold cavities and forming hollow spaces within the molded articles.