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:
May. 14, 2013
Filed:
Jun. 04, 2009
Chan-gi Jung, Incheon, KR;
Chan-Gi Jung, Incheon, KR;
Dae Won Kang Up Co., Ltd., , KR;
Abstract
A method of manufacturing a coil spring using a helicoid reduction mill includes supplying a coil spring material linearly unrolled by a prestraightener to a surface treatment machine and then short-blasting or scarfing its outer surface to surface-treat the coil spring material; primarily heating the surface-treated coil spring material to a predetermined temperature using a first heater; sequentially supplying and pressurizing the primarily-heated coil spring material in a stepwise fashion such that the coil spring material has the same diameter as that of a coil spring to be manufactured; measuring the diameter and the length of the coil spring material and then cutting the coil spring material to a desired size; secondarily heating the cut coil spring material to a predetermined temperature using a second heater; forming the secondarily heated coil spring material into a coil spring using a coiling machine; and oil-quenching and then tempering the formed coil spring.