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US 4,049,040 AGranted
Squeeze casting apparatus and method
AssigneeN L Industries, Inc.
InventorRichard F. Lynch
Life of this patent
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AssigneeN L Industries, Inc.
InventorRichard F. Lynch
Estimating the term…
An improved method of and apparatus for pressure casting metal are disclosed. The method is generally known in the art as "squeeze casting". The present method provides for casting articles under forging pressures in a die to predetermined dimensions regardless of varying amounts of excess of poured molten metal, by the inclusion of a retractable charge-quantity compensator positioned adjacent the casting cavity to form on the cast article an extension which may vary in volume from article to article. The extension is later removed. The charge-quantity compensator may be in the form of a piston in a cylinder with hydraulic fluid behind the piston connected to a hydraulic source. The piston, which may be normally biased toward the die cavity but yieldable away therefrom is fixed in position when the punch die has advanced to a predetermined position at which the quantity of casting material in the die cavity is appropriate for the article being formed. Full casting pressure is then applied. Multiple part casting dies may be used wherein multiple punch dies are connected to a common pressing head since variations in quantities of poured casting material are taken by the separate compensators associated with each of the die cavities.
A method of casting a metal article, comprising:
In a squeeze casting apparatus including a female die half for receiving a quantity of molten casting material, a movable punch die adapted to be moved a fixed distance into the female die half and closed in sealing engagement therewith to form a closed die cavity, and means for applying a high pressing force on the punch die toward the female die half, the improvement comprising:
In a squeeze casting apparatus including a female die cavity for receiving a quantity of molten casting material, a movable punch die adapted to be moved a fixed distance into the female die half and closed in sealing engagement therewith to form a closed die cavity, and means for applying a pressing force on the punch die toward the female die half, the improvement comprising a charge-quantity compensator including a bore leading from the die cavity through a portion of the female die half and oriented parallel to the path of movement of the punch die, a piston sealingly positioned within the bore and movable from a position adjacent the inside surface of the die cavity to a position retracted outwardly therefrom, means yieldingly resisting the movement of the piston away from the die cavity, and means for holding the piston stationary in response to the advancement of the movable punch die to a predetermined position short of said fixed distance in the female die half, whereby said pressing force may continue to be exerted on the punch die.
Dependencies are inferred from the claim text.