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:
Feb. 22, 1994
Filed:
Aug. 05, 1991
Tetsunori Matsuwaka, Okayama, JP;
Kenji Kobayashi, Okayama, JP;
Takashi Ogawa, Okayama, JP;
Tomonobu Ogino, Okayama, JP;
Motoo Ohmori, Akaiwa, JP;
Hiroshi Hanafusa, Wake, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An aluminum alloy ring (the outside diameter D.sub.1) which is an element of a rotary head cylinder, is inserted in a cavity (the inside diameter D.sub.2 >D.sub.1) of a fixed metal mold, with a clearance gap (D.sub.2 -D.sub.1) Then, the cavity of the fixed metal mold is closed by a movable metal mold, and the inner space of the aluminum alloy ring is filled with molten synthetic resin material. The filling resin is pressurized so that the aluminum alloy ring elastically expands until the outer diameter thereof D.sub.1 becomes exactly or almost equal to D.sub.2. After that, the filling synthetic resin material is cooled. Thus, the aluminum alloy ring and the synthetic resin material are integrated, resulting in a rotary head cylinder molding.