Donald L. Shawkey

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Sandy Lake, PA, US

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Patents Grantslast 30 patents

Information Patent Grant
Extension trestle ladder
- Patent number 4,240,522
- Issue date Dec 23, 1980
- R. D. Werner Co., Inc.
- Kenneth J. Spear
- E06 - DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL LADDERS