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:
Jul. 31, 1979
Filed:
Jan. 26, 1978
Takeo Tamamura, Hitachi, JP;
Naotatsu Asahi, Katsuta, JP;
Makoto Nakayama, Hitachi-ohta, JP;
Masataka Kasai, Mito, JP;
Akira Saito, Katsuta, JP;
Toshimichi Terada, Kanagawa, JP;
Hitachi, Ltd., , JP;
Abstract
Guiding drums for a magnetic tape scanning assembly for use in a video tape recorder and playback apparatus are made of a specific aluminum-silicon alloy consisting essentially of 8 to 15% by weight of silicon, 1 to 4% by weight of copper, 0.05 to 0.6% by weight of magnesium, and the balance being aluminum. A mean grain size of silicon crystal in eutectic structure is controlled to be 5 .mu.m or less. The drums are provided with a diagonal or helical guiding path on the peripheries thereof in which there are formed on the guiding path generally continuous, fine machining lines having a roughness (H max) of 1 to 6 .mu.m, preferably 2 to 5 .mu.m, in a direction parallel with sliding travel of a magnetic tape.