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:
Nov. 11, 2003
Filed:
Jun. 18, 2001
Hisato Shimizu, Nagano-ken, JP;
Hiroshi Koizumi, Nagano-ken, JP;
Kazutoyo Kobayashi, Nagano-ken, JP;
Nissei Plastic Industrial Co., Ltd., Nagano-ken, JP;
Abstract
An unstable weighing due to the plunger sliding resistance in a prepla type injection molding machine is prevented by dividing control of the plunger retraction movement for the weighing into speed control and pressure control. A plastic resin supply start position and a forced retraction release position are set along the way of the plunger retraction stroke by reference to a weighing start position. A plunger is moved from the weighing start position after injection and pressure-keeping to a weighing stop retraction position. Plastic resin is supplied to the forward portion of the injection cylinder when the plunger attains the supply start position from the weighing start position. The plunger is moved by forced retraction up to the forced retraction release position by speed control; the weighing is stabilized by changing the speed control to the pressure control once the plunger attains the forced retraction release position.