THREADED FASTENERS

A threaded fastener including a head, a shank connected to the head at a first end of the shank, the shank includes a first portion, a second portion, a third portion, and a tip at an end of the shank opposite the head. The fastener includes a first helical thread formation extending outwardly from the second and third portions of the shank, and a second helical thread formation extending outwardly from a section of the third portion of the shank that is adjacent to the tip. The first helical thread formation defines grooves in the section of the third portion of the shank that is adjacent to the tip.

CROSS-REFERENCE TO RELATED APPLICATION

This application is related to the following commonly owned co-pending patent application: U.S. Design Patent Application No, 29/879,919, entitled “THREADED FASTENER,” Attorney Docket No. 025140-2255.

BACKGROUND

The present disclosure relates to threaded fasteners. Threaded fasteners are widely commercially used throughout the world for securing various objects to various substrates. Various threaded fasteners include a head, a shank, and one or more thread formations extending from the shank for frictionally engaging the substrate into which the threaded fastener is driven.

Various threaded fasteners are used to secure objects to concrete, masonry, and other cementitious substrates. When the threaded fastener is rotated in a tightening direction, the threads of the thread formation(s) of the threaded fastener grip the inside surfaces of the substrate that define the cavity (such as the surfaces that define a pre-drilled hole in the substrate), causing the threaded fastener to be driven deeper into the substrate until the head of the threaded fastener comes into contact with the object being connected by the threaded fastener to the substrate (such as a bracket, flange, clip, or other mechanical device having a hole in it through which the shank of the fastener passes). In certain situations, a threaded fastener can experience frictional resistance forces that tend to impede the driving of the threaded fastener into the substrate. This can impart significant torsional stresses on the threaded fastener, placing the shank of the threaded fastener under shearing torsional stresses. These torsional stresses can be so great in certain circumstances such that they cause the threaded fastener to fail due to the forces placed on the shank of the threaded fastener. Certain failures can result in the shank breaking and the fastener having to be removed. These failures can occur in various sections of the shank.

Accordingly, there is a continuing need to provide threaded fasteners that reduce the likelihood of such failures.

SUMMARY

Various embodiments of the present disclosure provide a threaded fastener drivable into a substrate that reduces the likelihood that the threaded fastener will fail due to the forces placed on the shank of the threaded fastener. In various embodiments of the present disclosure, the fastener includes a head and a shank connected to the head at a first end of the shank. The shank includes a first portion, a second portion, a third portion, and a tip at an end of the shank opposite the head. The fastener includes a first helical thread formation extending outwardly from the second and third portions of the shank. The fastener includes a second helical thread formation extending outwardly from a section of the third portion of the shank that is adjacent to the tip. The first helical thread formation defines grooves in the section of the third portion of the shank that is adjacent to the tip. This configuration of components enables more of the material of the fastener to be employed for the formation of the shank, which enables the sections of the shank to have larger diameters, and which results in an overall stronger shank that thus reduces the likelihood of failures occurring in the various sections of the shank.

Other objects, features, and advantages of the present disclosure will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts.

DETAILED DESCRIPTION

While the systems, devices, and methods described herein may be embodied in various forms, the drawings show, and the specification describes certain exemplary and non-limiting embodiments. Not all components shown in the drawings and described in the specification may be required, and certain implementations may include additional, different, or fewer components. Variations in the arrangement and type of the components; the shapes, sizes, and materials of the components; and the manners of connections of the components may be made without departing from the spirit or scope of the claims. Unless otherwise indicated, any directions referred to in the specification reflect the orientations of the components shown in the corresponding drawings and do not limit the scope of the present disclosure. Further, terms that refer to mounting methods, such as mounted, connected, etc., are not intended to be limited to direct mounting methods but should be interpreted broadly to include indirect and operably mounted, connected, and like mounting methods. This specification is intended to be taken as a whole and interpreted in accordance with the principles of the present disclosure and as understood by one of ordinary skill in the art.

Referring now to the Figures, a threaded fastener100of one example embodiment of the present disclosure is shown inFIGS.1,2,3,4,5,6,7,8,9,10,11, and12. The threaded fastener100may sometimes be referred to herein as the “fastener” for brevity. The fastener100is configured for use to secure an object to a substrate (such as but not limited to a concrete, masonry, and other cementitious substrate).

The threaded fastener100includes a head110, a shank150connected to the head110, and thread formations220and260connected to and extending outwardly from the shank150. The head110, the shank150, and the thread formations220and260are monolithically formed from a metal material such as steel. In certain example embodiments, the steel is an AISI 1022 low carbon steel. The configuration of the threaded fastener100of the present disclosure maximizes the material used for the formation of the shank150while still providing the head110and the thread formations220and260that provide their desired functionality for the fastener100. In other words, the present disclosure takes into account that for the formation of fastener, only a limited amount of material (such as steel) can be used to create the fastener, and specifically that during the formation process, only that limited amount of material can be used to form the head, the shank, and the thread formation(s) of the fastener. Thus, there is a trade off in the relative sizes and strengths of these components. For example, if a manufacturer wants a fastener that has four thread formations on the shank, the material for those four thread formations needs to come from the head or the shank, and thus the shank may need to be narrower. The present disclosure provides for a configuration of the fastener100including its head110, its shank150, and its thread formations220and260that provide the desired functionalities needed from the head110and the thread formations220and260while still maximizing the diameter and strength of the shank150.

The head110includes a top portion120spaced from the shank150and a bottom portion140proximate the shank150. The top portion120of the head110defines a mechanical engaging structure122that is engageable by an appropriate tool (not shown) for driving the fastener100. In this example embodiment, the mechanical engaging structure122includes defines a cross-shaped slot configured to receive a tool such as a Phillips head screwdriver. In other embodiments, the mechanical engaging structure defines a straight slot configured to receive a flathead screwdriver. In other embodiments, the mechanical engaging structure defines a hexagonal shaped cavity configured to receive an Allen wrench. In other embodiments, the mechanical engaging structure includes a hexagonal shaped bolt head engageable by an appropriate tool such as a socket or wrench. Any known or subsequently developed suitable mechanical engaging structure can be used as the engaging structure of the fastener100in accordance with the present disclosure. The bottom portion140of the head110includes a bottom surface (not separately labeled). The bottom surface generally faces away from the head110and towards the shank150. The bottom portion140can include a plurality of ribs (not shown) extending from the bottom surface. In various such embodiments, the ribs can be arranged radially around a central axis A1 of the fastener100and thus the head110(which would extend through line A1-A1). The head110can be alternatively configured in accordance with the present disclosure.

The shank150includes a first shank portion160, a second shank portion170, a third shank portion180, and a tip190. The shank150including the first shank portion160, the second shank portion170, the third shank portion180, and the tip190has a length L as shown inFIG.2.

The first shank portion160includes a first end (not labeled) connected to the head110(at a first end of the shank150) and a second end (not labeled) connected to the second shank portion170. The first shank portion160has a constant or substantially constant outer diameter along the length of the first shank portion160. In this embodiment, no thread formations extend from the first shank portion160.

The second shank portion170includes a first end (not labeled) connected to the first shank portion160and a second end (not labeled) connected to the third shank portion180. The second portion170has a decreasing outer diameter from section thereof connected to the first shank portion160to section thereof connected to the third shank portion180. In this embodiment, only part of the first thread formation220extends from the second shank portion170, and none of the second thread formation260extends from the second shank portion170.

The third shank portion180includes a first end (not labeled) connected to the second shank portion170and a second end (not labeled) connected to the tip190. The tip190includes a first end (not labeled) connected to the third shank portion180and a pointed second end196. The third shank portion180has a constant or substantially constant outer diameter along the length of the third shank portion180. In this embodiment, part of the first thread formation220extends from the third shank portion180, and the second thread formation260extends from the part of the third shank portion180.

The tip190is pointed to aid in penetrating the substrate in which the fastener100is being driven. The tip190can be alternatively configured in accordance with the present disclosure. The tip190has a decreasing outer diameter from section thereof connected to the third shank portion180to the tip196thereof.

The shank150has a longitudinal axis A1 extending along the length L of the shank150from the head110to the end of the pointed second end196of the tip190.

In a first example embodiment that is a 3/16 inch fastener, the outer diameter of the first shank portion160is 0.148 inches (3.7592 mm) and the outer diameter of the third shank portion180is 0.133 inches (3.3528 mm).

In a second example embodiment that is a 4 inch fastener, the outer diameter of the first shank portion160is 0.189 inches (4.8006 mm) and the outer diameter of the third shank portion180is 0.173 inches (4.3942 mm).

The fastener100includes a first helical thread formation220connected to, extending along, and extending outwardly from the second portion170of the shank150and from the third portion180of the shank150.

The first helical thread formation220includes a plurality of threads (not individually labeled) that span all or substantially all of the second and third portions170and180of the shank150.

The first helical thread formation220extends along the second and third portions170and180of the shank150in a helical or spiral formation in the direction of the longitudinal axis A1 of the fastener100.

The first helical thread formation220includes a root222adjacent the outer surfaces (not labeled) of the second and third portions170and180of the shank150.

The first helical thread formation220includes a crest230opposite the root222and spaced from the outer surfaces (not labeled) of the second and third portions170and180of the shank150.

The first helical thread formation220includes a trailing surface224extending from the root222to the crest230(at a 110 degree angle or approximately a 110 degree angle relative to the outer surface of the third portion180of the shank150in this example embodiment).

The first helical thread formation220includes a leading surface226extending from the root222to the crest230(at a 110 degree angle or approximately a 110 degree angle relative to the outer surface of the third portion180of the shank150in this example embodiment).

The leading surface224and the trailing surface226intersect at the crest230(at a 40 degree or approximately a 40 degree angle in this example embodiment). The crest can have a sharp edge or a somewhat flattened edge in various different embodiments. In this example embodiment, the leading surface224and the trailing surface226thus define a 40 degree or approximately a 40 degree angle thread angle of the first helical thread formation220.

These angles are applicable to both the example 3/16 inch and 4 inch fasteners described herein.

In this example configuration, less material needs to be used to form the first helical thread formation220due to these relatively smaller angles (when compared to various commercially available fasteners). In this example configuration for the fastener100, the material that could be used for the first helical thread formation220to make these angles larger is rather used for increasing the outer diameter of the shank150and thus making the shank150stronger.

In a first example embodiment that is a 3/16 inch fastener, the first helical thread formation220has a 0.129 inch (3.2766 mm) pitch length.

In a second example embodiment that is a 4 inch fastener, the first helical thread formation220has a 0.133 inch (3.3782 mm) pitch length.

In a first example embodiment that is a 3/16 inch fastener, the first helical thread formation220has an outer 0.208 inch (5.2832 mm) diameter.

In a second example embodiment that is a 4 inch fastener, the first helical thread formation220has an outer 0.250 inch (6.35 mm) diameter.

The outer diameter of the first helical thread formation220is substantially constant along the length of the second portion170and the third portion180of the shank150(except for the leading and terminating sections thereof that are downwardly tapered toward the shank150).

As best shown inFIGS.2,8and9, the first helical thread formation220includes a first thread portion240and a second thread portion250.

In this example embodiment, the second thread portion250extends for the bottom three pitch lengths of the first helical thread formation220that are adjacent the tip190.

The first thread portion240extends for the rest of the pitch lengths of the first helical thread formation220.

The first thread portion240of the first helical thread formation220does not define any include any grooves. This reduces the torsional forces on this second portion170of shank150and on the upper section of the third portion180of the shank150.

The second thread portion250of the first helical thread formation220defines a plurality of spaced-apart grooves. As best shown inFIGS.8,9,10, and11, in this example embodiment, the grooves are each partially defined by a first cutting surface (not labeled) and a second cutting surface (not labeled). It should be appreciated that the surfaces that define each groove can vary in accordance with the present disclosure. It should be appreciated that all of the grooves are identically configured in this example embodiment, but that one or more of the grooves may be alternatively configured.

The fastener100also includes a second helical thread formation260connected to, extending along, and extending outwardly from a lower section of the third portion180of the shank150adjacent the tip190. The second helical thread formation260includes a plurality of threads (not individually labeled) that extend along a lower section of the third portion170of the shank150in a helical or spiral formation in the direction of the longitudinal axis A1 of the fastener100.

The second helical thread formation260only spans the section of the third portion180of the shank150that is adjacent to the tip190. In this embodiment, the second helical thread formation260spans the same section or substantially the same section as the second thread portion250of the first helical thread formation220. In this example configuration, less material needs to be used to form the second helical thread formation260due to its relatively short length. In this example configuration for the fastener100, the material that could be used for the second helical thread formation260to span the second and third sections170and180of the shank150is rather used for increasing the outer diameter of the shank150and thus making the shank150stronger.

The threads of the second helical thread formation260are positioned between the threads of the first helical thread formation220.

The second helical thread formation260includes a root262adjacent the outer surface of the third portion180of the shank150.

The second helical thread formation260includes a crest270opposite the root262and spaced from the outer surface of the third portion180of the shank150.

The second helical thread formation260includes a trailing surface264extending from the root262to the crest270(at a 110 degree angle or an approximately 110 degree angle relative to the outer surface of the third portion180of the shank150in this example embodiment).

The second helical thread formation260includes a leading surface266extending from the root262to the crest230(at a 110 degree angle or an approximately 110 degree angle relative to the outer surface of the third portion180of the shank150in this example embodiment).

The leading surface266and the trailing surface264intersect at the crest270(at a 40 degree angle or an approximately 40 degree angle in this example embodiment). The crest can have a sharp edge or a somewhat flattened edge in various different embodiments. The leading surface266and the trailing surface264thus define a 40 degree or approximately 40 degree thread angle of the second helical thread formation260in this example embodiment.

These angles are applicable to both the example 3/16 inch and 4 inch fasteners described herein.

In a first example embodiment that is a 3/16 inch fastener, the second helical thread formation260has a 0.129 inch (3.2766 mm) pitch length.

In a second example embodiment that is a 4 inch fastener, the second helical thread formation260has a 0.133 inch (3.3782 mm) pitch length.

In a first example embodiment that is a 3/16 inch fastener, the second helical thread formation260has an outer 0.150 inch (3.81 mm) diameter.

In a second example embodiment that is a 4 inch fastener, the second helical thread formation260has an outer 0.200 inch (5.08 mm) diameter.

The outer diameter of the second helical thread formation260is substantially constant along the length of the third portion180of the shank150(except for the leading and terminating sections thereof which are downwardly tapered).

The second helical thread formation260does not defines any grooves in this example embodiment.

In this example configuration, less material needs to be used to form the second helical thread formation260due to these relatively smaller angles. In this example configuration for the fastener100, the material that could be used for the second helical thread formation260to make these angles larger is rather used for increasing the outer diameter of the shank150and thus making the shank150stronger.

In this example embodiment, the fastener100does not include any other helical thread formations connected to, extending along, and extending outwardly from shank.

Thus, in this example embodiment, the fastener100includes a head110and a shank150connected to the head110at a first end of the shank150. The shank150includes a first portion160, a second portion170, a third portion180, and a tip190at an end of the shank150opposite the head110. The fastener100includes a first helical thread formation220extending outwardly from the second and third portions170and180of the shank150. The fastener110includes a second helical thread formation260extending outwardly from a section of the third portion180of the shank150that is adjacent to the tip190. The first helical thread formation220defines grooves in the section of the third portion180of the shank150that is adjacent to the tip190. This configuration enables material that would otherwise be used for a second thread formation that extends the entire length of the first thread formation to be used for making the shank150have a relatively larger diameter and thus making the shank150stronger.

This configuration of the threaded fastener100provides significant advantages in increasing the torsion strength of the fastener, and particularly of the shank150, and thus reducing the likelihood of failure of the shank150and undesirable failures of the fastener100.

It should be appreciated that the fastener100is a right-handed threaded fastener, such that when it is turned in a clockwise fashion about axis A1 (when looking at the top portion120of the head110), the fastener100is tightened or driven, and when turned in a counter-clockwise fashion about axis A1 (when looking at the top portion120of the head110), the fastener100is loosened or backed out. It should be appreciated that the fastener could be formed as a left-handed threaded fastener, with the parts reversed.

FIG.13shows a sectional view of part of one of the threads of one example embodiment of a threaded fastener in accordance with the present disclosure. In this example embodiment,FIG.13shows the cross-section of the relatively larger thread of the threaded fastener described above.

In this example, the first helical thread formation220A includes a crest230A opposite the root and spaced from the outer surfaces (not labeled) of the shank (not labeled).

The first helical thread formation220A includes a trailing surface224A extending from the root to the crest230A (at a 110 degree angle or approximately a 110 degree angle relative to the outer surface of the shank in this example embodiment).

The first helical thread formation220A includes a leading surface226A extending from the root to the crest230A (at a 110 degree angle or approximately a 110 degree angle relative to the outer surface of the shank in this example embodiment).

The leading surface224A and the trailing surface226A intersect at the crest230a(at a 40 degree or approximately a 40 degree angle in this example embodiment). The crest can have a sharp edge or a somewhat flattened edge (such as shown) in various different embodiments. In this example embodiment, the leading surface224A and the trailing surface226A thus define a 40 degree or approximately a 40 degree angle thread angle of the first helical thread formation220A.

FIG.14shows a sectional view of part of one of the threads of another example embodiments of a threaded fastener in accordance with the present disclosure. In this example embodiment,FIG.14shows the cross-section of the relatively larger thread of the threaded fastener described above. In this embodiment, the leading and trailing surfaces have alternative sections.

In this example, the first helical thread formation220B includes a crest (not labeled) opposite the root and spaced from the outer surfaces (not labeled) of the shank (not labeled).

The first helical thread formation220B includes a trailing surface having a first section222B, a second section231B connected to the first section222B, and a third section232B connected to the second section231B.

The first section222B extends from the root toward the crest (at a 110 degree angle or approximately a 110 degree angle relative to the outer surface of the shank in this example embodiment).

The second section231B extends from the first section222B toward the crest (at a 160 degree angle or approximately a 160 degree angle in this example embodiment).

The third section232B extends from the second section231B toward the crest (at a 135 degree angle or approximately a 135 degree angle in this example embodiment).

The first helical thread formation220B includes a leading surface having a first section230B, a second section234B connected to the first section230B, and a third section233B connected to the second section234B.

The first section230B extends from the root toward the crest (at a 110 degree angle or approximately a 110 degree angle relative to the outer surface of the shank in this example embodiment).

The second section234B extends from the first section230B toward the crest (at a 160 degree angle or approximately a 160 degree angle in this example embodiment).

The third section233B extends from the second section234B toward the crest (at a 135 degree angle or approximately a 135 degree angle in this example embodiment).

The third section233B of the leading surface and the third section232B of the trailing surface intersect at the crest (at a 90 degree or approximately a 90 degree angle in this example embodiment). The crest can have a sharp edge (such as shown) or a somewhat flattened edge in various different embodiments.

Generally, for fasteners, there is a trade off for sharp triangular thread cross section between thread angle and root diameter. In other words, as the material in the thread of the fastener is increased to maximize the holding power of the fastener (such as an increase in thread angle to 40 degrees, 50 degrees, or 60 degree), the material is taken from the root diameter, which can reduce torsional strength.

This above described and illustrated example embodiment thread configuration optimizes material allocation to both the root diameter of the thread geometry and the tip of the thread geometry. This illustrated example embodiment employs an optimal amount of material in the tip of the thread while maintaining holding power and while keeping torsional strength at an optimal level. This illustrated embodiment also helps to reduce wear while cutting threads in a substrate. By moving material in this configuration to the tip of the thread, this configuration resists wear during the thread tapping operation (such as when using the self-tapping fastener in substrates like concrete).

It will be understood that modifications and variations may be affected without departing from the scope of the novel concepts of the present invention, and it is understood that this application is to be limited only by the scope of the claims.