Method and apparatus for fastening steel framing members

Various improved methods are provided for fastening two of more steel framing members together with a fastener. In one aspect, the fastening technique employs a fastener having a tip section such that a portion of the tip section extending beyond the underside of the framing members may be outwardly flared, thereby inhibiting removal of the fastener from the framing members In another aspect, the fastening technique employs a fastener having a steel tip nose for piercing the framing members and a plastic stem section, such that a portion of the stem section extending beyond the underside of the framing members expands, thereby inhibiting removal of the fastener from the framing members. In yet another aspect, the fastening technique employs a fastener having a coil section with an elastic characteristic.

BACKGROUND OF THE INVENTION

The present invention relates generally to steel framing and, more particularly, to an improved cost-effective method for fastening steel framing.

Steel framing is revolutionizing the construction industry. Steel is a high quality framing material that will not shrink, warp, or attract termites and other wood boring insects. In recent years, the price of steel has become more competitive with wood and other construction materials. However, despite its advantages, steel framing has not become prevalent in the residential construction industry. The lack of a quick and cost effective technique for fastening steel members has prevented steel framing from emerging as the predominant building material in residential construction.

Therefore, it is desirable to provide a quick and cost-effective technique for fastening steel members. It is envisioned that the steel fastening technique will be comparable in speed to an air nailer used to fasten wood materials. It is further envisioned that the steel fastening technique will provide a minimal gap between steel members, a pullout force of at least 216 lb., a shear force of at least 164 lb., as well as cause minimal destruction of any galvanize coating on the steel members.

SUMMARY OF THE INVENTION

In accordance with the present invention, various improved methods are provided for fastening two of more steel framing members together with a fastener. In one aspect of the invention, the fastening technique employs a fastener having a tip section such that a portion of the tip section extending beyond the underside of the framing members may be outwardly flared, thereby inhibiting removal of the fastener from the framing members In another aspect of the present invention, the fastening technique employs a fastener having a steel tip nose for piercing the framing members and a plastic stem section, such that a portion of the stem section extending beyond the underside of the framing members expands, thereby inhibiting removal of the fastener from the framing members. In yet another aspect of the present invention, the fastening technique employs a fastener having a coil section with an elastic characteristic.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1, a fragmentary prospective view of a longitudinal steel framing member12having two upright steel framing members14and16fastened thereto. Each c-shaped framing member includes a bottom wall and two side walls having a thickness in the range from 0.018″ to 0.071″. Additionally, each steel member may range from 33 ksi to 80 ksi as is well known in the art. As will be more fully described below, one or more fasteners20may be used to join the upright steel framing members14and16to the longitudinal steel framing member12. While the following description is provided with reference to this particular configuration, it is readily understood that the fastening technique of the present invention is applicable to any two or more adjacent members made of steel (e.g., carbon steel, hardened steel, stainless steel, tool steel, etc.) or other material having similar attributes to those of steel (e.g., nonferrous metals, including nickel, alloys, titanium, copper and aluminum).

In accordance with one aspect of the present invention, one or more outwardly expanding fasteners20may be used to join the steel members. A first exemplary embodiment of an outwardly expanding fastener20is depicted in FIG.2. The fastener20is comprised of an integrally formed member having a head section22, a stem section24and a tip section26. The fastener20further includes a bore28which is formed into the head section22of the fastener. The bore28extends downwardly through the stem section24and into the tip section26of the fastener. As further described below, the bore28is adapted to receive a pin30therein. The fastener20is preferably comprised of a harden steel material or, alternatively, a softer steel material having a tip section formed of a hardened material such as carbide, ceramic, or a harden steel.

In operation, a two-step process is used to set the fastener20into the framing members. First, the expanding fastener20is driven into the steel members until the head of the fastener seats against the outer surface of the steel members as shown inFIGS. 4 and 5. It is readily understood that the driving device is configured to engage the head section22of the fastener and may provide a backplate to prevent unwanted deformation of the steel at the point at which the fastener pierces the steel members. In one embodiment, the driving device drives the fasteners at relatively high speeds (e.g., greater than 50 feet per second). In an alternative embodiment, the driving device may drive the fastener at lower speeds, but apply a relatively high force. One skilled in the art will readily recognize that an air nailer or other known driving devices may be configured to drive the fasteners20of the present invention into the steel members.

Once the fastener20has been driven into place, a pin30is then driven through the bore28and into contact with the inner surface of the tip section26of the fastener. Upon impact, the pin30forces a portion of the fastener extending beyond the underside of the steel members to project radially outward as shown inFIGS. 6 and 7. The radially flared portions of the tip section26prevents removal of the fastener from the steel members. To facilitate the separation of the tip section26, it is envisioned that one or more fracture lines32may be formed in the tip section26of the fastener20as depicted in FIG.3. It is further envisioned that the fracture lines may not extend to the distal end of the tip section26, thereby maintaining the structural integrity of the tip section26as it is driven into the framing members. Alternatively, separation of tip section26can be facilitated by forming the tip section26from two or more segmented members. The segmented members are not connected to one another at tip section26and, therefore, do not require fracture lines32to facilitate the separation of tip section26.

In one embodiment, the pin30resides in the bore28of the fastener as shown in FIG.2. In this case, the driving device may be configured to provide a two-step actuation mechanism: a first step for driving the fastener into the steel members, and a second step for driving the pin30into the bore of the fastener. In an alternative embodiment, it is envisioned that the pin30may be integrated into the driving device that drives the fastener20into the steel members.

A second exemplary embodiment of the expanding fastener20′ is depicted in FIG.8. As described above, the expanding fastener20is comprised of an integrally formed member having a head section22′, a stem section24′, and a tip section26′. However, in this embodiment, the tip section26′ of the fastener20′ is designed to project radially outward into a butterfly position as shown inFIG. 9; otherwise the expanding fastener20′ is set using the two step process described above.

A third exemplary embodiment of the expanding fastener20″ is depicted in FIG.10. Likewise, the expanding fastener20″ is primarily comprised of an integrally formed member having a head section22″, a stem section24″ and a tip section26″. However, an annular groove32″ may be formed along the outer surface of the stem section24″. As further described below, the annular groove32″ of the fastener20″ is designed to curl the inner surface of the hole made in the steel members. In addition, the fastener20″ may be configured with different fracture lines as shown inFIG. 11, or alternatively, configured with two or more segmented members.

Referring toFIGS. 12-14, the fastener20″ is again driven into the steel members until the head section22″ of the fastener seats against the outer surface of the steel members as shown in FIG.13. As the fastener passes through the steel members, the annular groove32″ crimps together the portion of the steel members extending below the underside of the steel members, thereby preventing separation of the two steel members. Once the fastener20″ has been driven into place, a pin30″ is then driven into the bore28″ of the fastener, thereby radially expanding the tip section26″ of the fastener as described above.

In another aspect of the present invention, one or more steel tip fasteners40may be used to join the steel members. An exemplary steel tip fastener40is shown in FIG.15. The steel tip fastener40is primarily comprised of an integrally formed member having a head section42and a stem section44. The member is preferably formed of a plastic material. In addition, the fastener40further includes a piercing nose46formed at the tip of the fastener, such that the steel nose42has a radial dimension slightly less than the radial dimension of the stem section44of the fastener40. The piercing nose46is preferably formed of steel or other materials having similar attributes to those of steel.

When the steel tip fastener40is driven into the steel members, the piercing nose46punches a hole clean through the steel members as shown inFIGS. 16 and 17. The plastic stem portion of the fastener then press fits into the hole as shown in FIG.18. Once the fastener has been driven into place, a portion of the plastic stem will extend past the underside of the steel members. It is envisioned that the friction of the plastic being forced though the hole at a high velocity will cause the portion of the stem extending past the underside of the steel members to expand as shown at48of FIG.18. In this way, the expanded plastic portion will prevent removal of the fastener from the steel members.

In another aspect of the present invention, one or more twisted spring fasteners60may be used to join the steel members. An exemplary spring fastener60is depicted inFIGS. 19 and 20. The spring fastener60is comprised of an integrally formed member having a head section62and a coil section64. The fastener is preferably comprised of a steel material, but may be comprised of other materials having an elastic characteristic, such as some plastic materials reinforced with glass, kevlar or graphite fibers.

A two-step process may be used to set the fastener60. First, a pilot hole is drilled or punched into the steel members. Second, the spring fastener60is screwed into the pre-drilled hole until the steel members are secured together as shown inFIGS. 21 and 22. It is envisioned that the head section62of the spring fastener60is adapted to receive one or more types of torque transmitting devices. One skilled in the art will readily recognize that various well known torque transmitting devices (such as a drill) may be used to apply the appropriate rotational torque and downward force to drive the fastener60into the steel members.

A fourth exemplary embodiment of the expanding fastener20′″ is depicted in FIG.23. Likewise, the expanding fastener20′″ is primarily comprised of an integrally formed member having a head section22′″, a stem section24′″ and a tip section26′″. However, teeth35′″ may extend along the outer surface of the stem section24′″. As further described below, the teeth35′″ of the fastener20′″ are designed to engage with an outer surface of the steel members to further inhibit removal of expanding fastener20′″. In addition, the fastener20′″ may be configured with different fracture lines or alternatively, configured with two or more segmented members.

Referring toFIGS. 23-24, the fastener20′″ is again driven into the steel members until the head section22′″ of the fastener seats against the outer surface of the steel members as shown in FIG.24. Once the fastener20′″ has been driven into place, a pin30′″ is then driven into the bore28′″ of the fastener, thereby radially expanding the tip section26′″ of the fastener as described above. The teeth35′″ engage with the outer surface of the framing members, thereby further inhibiting removal of the fastener20′″.

While the invention has been described in its presently preferred form, it will be understood that the invention is capable of modification without departing from the spirit of the invention as set forth herein.