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. 05, 1999
Filed:
Sep. 16, 1998
Douglas Williams, San Rafael, CA (US);
Jeff Shea, San Francisco, CA (US);
Other;
Abstract
A fume exhaust duct joint, a clamping collar for clamping two cylindrical dual-laminate duct sections joined by an internal slip collar, and a method for assembling the joint. A first embodiment of the clamping collar has two clamp portions each including a metal outer skin spot-welded to a metal inner skin. The inner skins have bifurcated protrusions whose bifurcations penetrate the duct section outer surfaces when the collar is tightened, and, optionally, two circumferential beads of fire retardant caulking. The inner skins and slip collar are bonded to duct section surfaces using a putty-like sealant including a settable admixture of curing agent and novolac epoxy resin. A second embodiment of the clamping collar, preferred for duct sections 3-inches in diameter or smaller, has a single circumferential clamp portion.