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. 26, 2002
Filed:
Jan. 31, 2000
Motohiro Miyasaka, Nagareyama, JP;
Toshikazu Takehana, Edosaki-machi, JP;
Hitachi Powdered Metal Co., Ltd., Chiba, JP;
Abstract
A cylindrical sintered material is placed in a cavity composed of die, a core disposed in the center of the die, and a pair of upper and lower punches provided within the die and compressed by the upper and lower punches. A gap is provided between an internal circumferential portion of the sintered material and an external circumferential portion of the core. Consequently, when the sintered material is compressed, plastic flow is produced at both ends of the sintered material so that an internal circumferential portions at corresponding portions protrude inward in a radius direction till the internal circumferential portions come into contact with the core, so that slide portions are formed.