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:
Aug. 04, 1987
Filed:
Apr. 03, 1986
Paul D Engdahl, Costa Mesa, CA (US);
Roger P Engdahl, Santa Ana, CA (US);
Other;
Abstract
A mechanical seismic instrument for recording relative horizontal displacements between the base and foundation of base-isolated buildings or other large structures during earthquakes. A rigid tripod-like arm is connected to the base of the structure; on the other end of the arm is a marking stylus. A record plate is connected to the foundation. When base and foundation move relative to one another, the stylus scribes a record trace on the record plate. Arm and record plate are mounted respectively on mounting plates which are connected and covered by a flexible enclosure. Timing marks on the record trace may be made by striking devices which tap against the shank of the stylus.