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. 28, 2009
Filed:
Sep. 22, 2005
Yoshikazu Ugai, Tokyo, JP;
Taizo Iwami, Tokyo, JP;
Yuji Nakahara, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Chiyoda-Ku, Tokyo, JP;
Abstract
An apparatus for manufacturing a ring-shaped powder compact () includes a ring-shaped die () having magnetic property formed by combining a plurality of arch-shaped members (), a lower core section () placed inside a curved inner surface of the die (), and lower and upper punches () for pressurizing both the die () and magnetic powder filled into a cavity formed between the die () and the lower core section () in an axial direction of the die (). The curved inner surface of the die () varies in cross-sectional shape from one position to next along the axial direction of the die () at least in part along the axial direction. A ring magnet manufacturing method includes filling the magnetic powder into the cavity and producing the ring-shaped powder compact () by pressurizing the magnetic powder in the cavity in the axial direction by means of the lower and upper punches () while applying a radially orienting magnetic field to the magnetic powder, and sintering the ring-shaped powder compact ().