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:
Jan. 21, 1992
Filed:
Dec. 03, 1990
Louis Thomas, Maywood, IL (US);
Illinois Tool Works Inc., Glenview, IL (US);
Abstract
A roofing washer useful with a fastener having a head and a shank, such as, for example, a roofing screw, and provided with an annular lip so as to restrain the head after the head has been driven past the annular lip is disclosed. As molded from a resilient, polymeric material, the roofing washer has a plurality of discrete cavities, which facilitate radial expansion of the annular lip, and a plurality of discrete ribs, which separate the discrete cavities. In one possible embodiment, each cavity has an inner, generally cylindrical wall, an outer, generally cylindrical wall, and two end walls, each defining a plane oriented at an acute angle relative to a radial plane. In a different embodiment, each cavity has two planar walls and a curved wall whereby the cavities have substantially triangular configurations.