The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 07, 1984
Filed:
Jan. 29, 1982
Hans Thurner, Baldham, DE;
Bayerisches Druckguss-Werk Thurner KG, Markt Schwaben, DE;
Abstract
A method and apparatus for casting molten metal in a die casting machine having matching die assemblies movable between open and closed positions, a plunger for injecting molten metal into the die cavity, a vacuum system for evacuating the die cavity during injection of molten metal and a vacuum control valve for opening and closing the exhaust passage through which the air is evacuated. A fluid cylinder is mounted on one die assembly with its piston rod coupled to the valve rod of the vacuum control valve. The fluid cylinder has a solenoid-operated control valve actuated by an electric switch operated by movement of the molten metal injection piston so that the vacuum control valve begins to close at a predetermined point during the injection stroke. The injection plunger also actuates a timer at the same time it actuates the solenoid-operated control valve. As the vacuum control valve approaches its closed position, it actuates another switch that initiates the final injection stroke of the injection piston. If the latter switch is not actuated by the time the timer times out, the injection plunger is retracted before injection of molten metal is completed, so that no molten metal can enter the vacuum passages due to incomplete closure of the vacuum valve.