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:
Apr. 09, 1991
Filed:
Feb. 22, 1990
Keizo Hakoda, Kobe, JP;
Hisashi Samejima, Kobe, JP;
Bando Kagaku Kabushiki Kaisha, Kobe, JP;
Abstract
A mold for injection molding including a cylindrical outer mold and a columnar inner mold. The inner mold is provided, on its external circumferential surface, with a large number of tooth-shaped grooves extending in the axial direction thereof, and it is placed inside the outer mold to define an annular cavity between the external circumferential surface of the inner mold and the internal circumferential surface of the outer mold. The outer mold is provided with a plurality of runners extending axially near the internal circumferential surface. The runners are arranged at regular annular intervals along the circumference of the outer mold. Furthermore, slit-shaped gates are formed along the full length of the runners, the gates opening into the internal circumferential surface of the outer mold, in such a way that the inflow of molten molding material flowing from each runner into the cavity is gradually reduced along the runner from the upstream side towards the downstream end.