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:
Mar. 19, 1996
Filed:
Sep. 15, 1994
Yosuke Sasaki, Zama, JP;
Hideaki Okubo, Hiratsuka, JP;
Kabushiki Kaisha Komatsu Seisakusho, Tokyo, JP;
Abstract
In an injection and compression molding process wherein molten material is fed by a screw, incorporating a counterflow preventing valve (CPV), through a flow control valve (FCV) into a mold cavity, the injection volume is controlled by: with the FCV closed, feeding a predetermined quantity of material through the CPV into a chamber between the CPV and the FCV, then advancing the screw with the FCV maintained closed to cause the CPV to close, thereby raising the pressure of the material in the chamber, determining when the pressure of the material in the chamber reaches a predetermined pressure, determining whether the movable die is at a predetermined distance from the stationary die, opening the FCV after the pressure of the material in the chamber has reached said predetermined pressure and the movable die is at the predetermined distance from the stationary die, setting as an original point of a determination of the injection volume either (a) a position of the screw at the opening of the FCV or (b) a time at the opening of the FCV, injecting the material into the mold cavity while the mold cavity is open to atmospheric pressure, closing the FCV either (a) when the screw has reached a position advanced a predetermined distance from the thus set original point or (b) at a predetermined time after the thus set original point, and compressing the material in the mold cavity.