Lightweight cementitious roofing
Patent 5323581 Issued on June 28, 1994. Estimated Expiration Date: 
April 30, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
April 30, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesInventorApplicationNo. 876382 filed on 04/30/1992US Classes:52/519, Interfitted sections52/535, Plural offset portions52/539, Tongue and groove52/541RabbetExaminersPrimary: Friedman, Carl D.Assistant: Yip, Winnie Attorney, Agent or FirmForeign Patent References
International ClassE04D 001/22AbstractA lightweight roofing shingle or tile having an elongated body with top and bottom surfaces that taper lengthwise of the body, the body having laterally spaced, elongated edges; the body having a mid-region and a recess sunk upwardly into the mid-region, from the bottom surface; the recess extending widthwise of the body to intersect the body laterally spaced edges whereby the recess is adapted to receive a batten to support the body mid-region when installed on a roof. A secondary taper on the tile bottom surface engages the roof to provide leverage resisting wind up-lift forces exerted on the lightweight tile acting to rotate the tile about a nailing point fulcrum. | |
