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:
Jun. 29, 1993
Filed:
Apr. 03, 1991
Applicant:
Inventors:
Akihiko Yamamoto, Ibaraki, JP;
Toshihiro Yamada, Ibaraki, JP;
Tatsuo Natori, Kashiwa, JP;
Kotaro Naya, Shimizu, JP;
Motohiro Satoo, Ibaraki, JP;
Mitsuru Fujiwara, Ibaraki, JP;
Katsumi Matsubara, Ushiku, JP;
Kazuaki Shiinoki, Shimizu, JP;
Hirotaka Kameya, Ibaraki, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C21D / ;
U.S. Cl.
CPC ...
148587 ; 427305 ; 427319 ; 4273741 ; 4273742 ; 4273743 ; 4273881 ; 427438 ; 428612 ; 428614 ; 428622 ; 428623 ; 428626 ; 428679 ; 428680 ; 428936 ;
Abstract
A method treating a surface of rotors in a screw-type rotary fluid machine, with the method comprising the steps of: conducting a non-electrolytic Ni plating on the surface of each rotor so as to form a first layer of non-electrolytic Ni plating layer; heating the rotor having the first layer at a temperature not lower than 500.degree. C.; and forming, at least, a second layer of an organic resin so as to cover the first layer.