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:
Mar. 30, 2004
Filed:
Jul. 18, 2002
Chan Bok Lee, Chungjoo-si, KR;
Sinclair Worldwide, Inc., Seoul, KR;
Abstract
A hinge for collapsible ladders, includes an external frame including a center aperture and a pair of locking apertures; an inner frame rotatable with the external frame and including a center aperture and pairs of locking apertures; a rotary plate rotatably disposed between the frames and having locking apertures; a substantially flat rotary spring having one end mounted to the inner frame and an opposite end mounted to the rotary plate; a hub member rotatably connecting the frames about the center apertures, and including a locking end at one side; a locking part for extension into the locking apertures to fix an angle of the frames relative to each other; a press axle connected with the locking part, passing through the hub member, and including a bearing end; and a spring positioned between the hub member locking end and the press axle bearing end.