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:
Mar. 31, 1992
Filed:
Aug. 01, 1991
Syed R Hasan, Palatine, IL (US);
Michael P Ditka, Deerfield, IL (US);
Illinois Tool Works Inc., Glenview, IL (US);
Abstract
A composite fastener comprised of a roofing screw and a roofing washer. The screw shank has a leading portion, which is threaded, and a locking portion. The locking portion has a substantially frusto-conical part adjoining the leading portion and an additional part adjoining the screw head. The substantially frusto-conical part defines a major diameter where it adjoins the additional part and a minor diameter where it adjoins the leading portion. Two locking tabs extend from the substantially frusto-conical part, in diametric opposition to each other, in such manner that an imaginary cylinder coaxial with the shank and with a diameter equal to the major diameter divides each tab into a proximal part inside the cylinder and a distal part outside the cylinder. The washer has an aperture with a margin that flexes the tabs to allow the tabs to pass through the aperture.