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. 27, 2021
Filed:
Jun. 28, 2018
Mitsubishi Steel Mfg. Co., Ltd., Tokyo, JP;
Hironobu Sayama, Ichihara, JP;
Abstract
A hollow spring includes a steel tube in which the average of surface roughness is smaller than 10 μm across the entire inner surface of the steel tube and/or compressive residual stress is given to the entire inner surface of the steel tube. The hollow spring may be manufactured by a step of polishing the inner surface of the steel tube by flowing a viscoelastic abrasive medium () within the tubular member (), between a first opening () and a second opening () of the tubular member (). The abrasive medium () may include a viscoelastic base material and a granular abrasive. The inner surface of the steel tube is polished evenly to reduce the surface roughness and/or is given compressive residual stress to increase the fatigue life of the hollow spring.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile