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:
Oct. 31, 1995
Filed:
Oct. 24, 1994
Lamont R McClain, St. Louis, MO (US);
Engel Industries, Inc., St. Louis, MO (US);
Abstract
Rectangular sheet metal duct sections with integral outwardly-and-rearwardly formed end flanges are conventionally made from coiled strip metal to lengths provided by the width of the coil stock, ordinarily slightly less than five feet. As is common practice, outward-and-reverse facing flanges are formed on both ends of each wall of the duct section. The spaces between the flange ends at the corners of the duct section are filled by heavier cornerpieces having arms projecting at right angles. Crimping the outstanding flanges over the corner arm portions completes a duct section. According to the present invention, a linear array of embossed surface portions is formed in the duct wall close to each outwardly projecting flange portion and beneath its reverse-facing portion. Manually inserting and pressing the cornerpiece arms to lodge their inner edges between the line provided by these embossed portions and the adjacent first flange portions, supports each cornerpiece in its position for subsequent crimping thereover of the reverse flange portions.