Illinois Tool Works Inc.

Michael P Ditka

Syed R Hasan

Larry Reinhard

Mark A Packard

A depth-insensitive concrete fastener system is provided for securing roofing insulation materials to concrete roofing or decking. The concrete roofing or decking substructure is provided with a pre-drilled hole or bore having a predetermined diametrical extent. An anchor bolt fastener comprises a head portion, a pointed tip portion, and a shank portion interconnecting the head and tip portions. The shank portion has a first relatively smooth shank portion disposed adjacent to the head portion and extending toward the tip portion, and a second ribbed portion disposed adjacent to the tip portion and having an axial extent which is only a fractional portion of the entire axial extent of the fastener. The diametrical extent of the first smooth shank portion is less than that of the pre-drilled hole or bore defined within the concrete substructure, whereas the diametrical extent of the second ribbed shank portion is greater than the diametrical extent of the pre-drilled hole or bore defined within the concrete substructure. Therefore, when the anchor bolt fastener is impactly driven into the pre-drilled hole or bore of the concrete substructure, an interference or friction fit is defined between the anchor bolt fastener and interior sidewalls of the concrete substructure defining the pre-drilled hole or bore only along the axial extent of the second ribbed shank portion of the bolt fastener. Consequently, the fastener system is rendered depth-insensitive in that regardless of the depth to which the anchor bolt fastener is driven into the concrete substructure, the installation force does not increase beyond a predetermined limit. A roofing washer element may be pre-assembled upon the anchor bolt fastener as a result of being captured between the head and second ribbed shank portions of the bolt fastener.

Easy drive concrete fastener system

A depth-insensitive concrete fastener system is provided for securing roofing insulation materials to concrete roofing or decking. The concrete roofing or decking substructure is provided with a pre-drilled hole or bore having a predetermined diametrical extent. An anchor bolt fastener comprises a head portion, a pointed tip portion, and a shank portion interconnecting the head and tip portions. The shank portion has a first relatively smooth shank portion disposed adjacent to the head portion and extending toward the tip portion, and a second ribbed portion disposed adjacent to the tip portion and having an axial extent which is only a fractional portion of the entire axial extent of the fastener. The diametrical extent of the first smooth shank portion is less than that of the pre-drilled hole or bore defined within the concrete substructure whereas the diametrical extent of the second ribbed shank portion is greater than the diametrical extent of the pre-drilled hole or bore defined within the concrete substructure. Therefore, when the anchor bolt fastener is impactly driven into the pre-drilled hole or bore of the concrete substructure, an interference or friction fit is defined between the anchor bolt fastener and interior side-walls of the concrete substructure defining the pre-drilled hole or bore only along the axial extent of the second ribbed shank portion of the bolt fastener. Consequently, the fastener system is rendered depth insensitive in that regardless of the depth to which the anchor bolt fastener is driven into the concrete substructure the installation force does not increase beyond a predetermined limit. A roofing washer element may be pre-assembled upon the anchor bolt fastener as a result of being captured between the head and second ribbed shank portions of the bolt fastener.

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.

Roofing fastener and improved screw therefor

An anchoring device having a head and a shank to be forcibly driven into a hole defined within concrete or is disclosed. The shank has proximal, transitional, and distal portions defining respective axes that do not coincide when the shank is unstressed and further defining proximal and distal elbows. Notches enhancing frictional engagement between the shank and the hole wall are formed along convex surfaces of the elbows, as well as long substantially cylindrical surfaces of the proximal, transitional, and distal portions of the shank.

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Deerfield, IL, United States of America

Michael P Ditka