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:
Sep. 26, 1989
Filed:
May. 03, 1988
Zorica Pavlov, Hinsdale, IL (US);
Vijay B Patel, Orland Park, IL (US);
Allied Tube & Conduit Corporation, Harvey, IL (US);
Abstract
A metallic wall having coined knockouts. The wall includes a first surface and a second surface spaced from the first surface. A plurality of spaced knockout portions are positioned in incipient apertures in the wall and are disposed substantially between the surfaces. Each knockout portion is defined by a first indentation encompassing the knockout portion and extending from the first surface, and by a second indentation encompassing the knockout portion and extending form the second surface. These indentations are in alignment with a web of material of substantially uniform thickness throughout its length spacing the indentations. The outside surface defining the first indentation is inclined inwardly. A coating is applied to the second surface after formation of the indentations. A sharp blow to the knockout portion from the second surface fractures the web to allow removal of the knockout portion without any material of the wall extending substantially beyond the first surface. A method of fabricating galvanized steel tubing having the knockout portions is also disclosed.