COMPOSITE DECK FASTENER

Abstract

A direct fastening fastener particularly suited for use in normal weight or lightweight composite deck system. The fastener is heat treated to a dual-hardness level so that a portion of the fastener is capable of driving into the support member, such as a joist and a decking member. The remaining portion of the fastener remains relatively ductile so that it can withstand and transfer shear loads imposed by shifting of the concrete slab, which overlies the composite decking, to the support member. The fastener can be a single or multiple piece fastener which includes specially formed annular flanges that enhance interlocking between the fastener, the concrete slab and support members.

Claims

1. A fastener comprising: a striking unit including a driving head having a top surface capable of being stricken by a driving member and a bottom surface; an elongated shank along a longitudinal axis of the fastener, the elongated shank operatively connected to the striking unit and extending from the bottom surface of the striking unit; an insertion member integral with the elongated shank and disposed at an opposite end from the striking unit, the insertion member having a textured portion and a tip portion, and a first annular flange disposed between the elongated shank and the insertion member, wherein at least a portion of the insertion member is heat treated to enable the tip portion to drive into a decking member.

2. The fastener according to claim 1, wherein the insertion member is heat treated to a hardness greater than the hardness of the elongated shank and striking unit.

3. The fastener according to claim 1, wherein the insertion member is hardened to 54 minimum Rockwell C while the elongated shank and striking unit of the fastener are hardened to 50%-70% of the insertion member.

4. The fastener according to claim 1, wherein the insertion member comprises a rounded profile.

5. The fastener according to claim 1, wherein the insertion member comprises one of a stepped profile and a straight profile.

6. The fastener according to claim 1, wherein the striking unit comprises a plurality of recesses.

7. The fastener according to claim 1, wherein the striking unit is threadedly engaged with the elongated shank.

8. The fastener according to claim 1, wherein the insertion member comprises a textured portion.

9. The fastener according to claim 8, wherein the textured portion comprises a knurled portion.

10. The fastener according to claim 9, wherein the knurled portion comprises one of a helix diamond pattern and a spiral pattern.

11. The fastener according to claim 1, further comprising a second annular flange on the striking unit, the second annular flange extending radially outward from the longitudinal axis of the fastener and having a diameter greater than the diameter of the driving head, the second annular flange and the driving head defining an annular recess therebetween.

12. A fastener comprising: an elongated shank having an end portion with a top surface capable of being stricken by a driving member; an insertion member integral with the elongated shank at an opposite end from the end portion, the insertion member having a textured portion and a tip portion; an annular flange disposed between the insertion member and the end portion; and a threaded portion along the elongated shank adjacent to the end portion, wherein at least a portion of the insertion member is heat treated to enable the tip portion to drive into a decking member.

13. The fastener according to claim 12, further comprising a nut threaded around the threaded portion of the elongated shank.

14. A fastener, comprising: an elongated shank with a longitudinal axis, a first end, and a second end; a striking unit positioned at the first end; an insertion member positioned at the second end, the insertion member including a tip portion; at least one annular flange formed on the elongated shank and extending radially outward; and at least one ridge formed on the insertion member and defining a helix around the longitudinal axis, wherein at least a portion of the tip is heat treated and textured to enable the tip portion to drive into a decking member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a fragmentary perspective view of a typical composite deck structure using new direct fastening fasteners incorporating the unique features of the present invention;

[0025] FIG. 2 is an enlarged fragmentary cross-sectional view taken substantially along the line 2-2 of FIG. 1;

[0026] FIG. 3 is an enlarged side view of the fastener shown in FIGS. 1 and 2;

[0027] FIG. 4A is an exemplary view of the fastener according to a second embodiment of the invention. FIG. 4B is an enlarged view of an area of the fastener that is heat treated to a relatively high degree of hardness;

[0028] FIG. 5A is an exemplary view of the fastener according to a third embodiment of the invention. FIG. 5B is an enlarged view of an area of the fastener that is heat treated to a relatively high degree of hardness;

[0029] FIG. 6A is an exemplary view of the fastener according to a fourth embodiment of the invention. FIG. 6B is an enlarged view of an area of the fastener that is heat treated to a relatively high degree of hardness;

[0030] FIGS. 7A and 7B illustrate a cross-sectional view of an embodiment of a driving tool for driving the fastener into the composite deck structure;

[0031] FIG. 8 is an exemplary view of the fastener according to a fifth embodiment of the present invention;

[0032] FIG. 9 is an exemplary view of the fastener according to a sixth embodiment of the present invention;

[0033] FIG. 10 is an exemplary view of the fastener according to a seventh embodiment of the present invention; and

[0034] FIG. 11 is an exemplary view of the fastener according to an eighth embodiment of the present invention.

[0035] While the invention is susceptible of various modifications and alternative constructions, a certain illustrated embodiment hereof has been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0036] Referring to FIG. 1, for purposes of illustration, the present invention is shown in the drawings as embodied in a direct fastening pin or fastener 10. A direct fastening fastener is a fastener that can be driven from a powered fastener driving tool, such as the driving tool 2, shown in FIGS. 7A and 7B. The direct fastening fastener (herein “fastener”) 10 is especially useful as a fastener in deck systems that are used as floors or roof decks in modern buildings. A floor or roof deck is subject to shear forces that tend to cause a horizontal, or shearing movement of the deck relative to its support structure. The fastener 10 of the present invention restricts and transfers this shearing movement when used in a composite deck system.

[0037] A composite deck system, such as in composite deck system 11, is typically fabricated at a building site by joining primary structural members to secondary structural members. In an embodiment, primary structural members 8 can be metal and include a decking member 15 and a support member, namely an upper elongated horizontal joist member 13A. The fastener 10 is driven through the primary structural members 8 as shown in FIGS. 1 and 2. Secondary structural members 12 can also be metal and include a lower elongated horizontal joist member 13B and a web member 14. The structural members 8 and 12 include joist members or beams, but not are restricted to these members. During construction of a building, the secondary structural members 12 are joined to the building structural support beams (not shown). The primary structural members 8 are then joined to the secondary structural members 12. Joist members, such as steel joists, are typically comprised of vertically spaced upper and lower elongated horizontal joist members 13A and 13B, and supporting web members 14 joined to and extending between the horizontal joist members. In lightweight composite deck systems, the joist members are formed with material cords having a relatively thin cross-section (e.g., less than 0.200″).

[0038] The decking member 15, such as, for example, the metal decking shown in FIG. 1, is typically laid over and spans adjacent joist members 13A so that corrugations, if present, run at a right angle to the joists. In an embodiment, the composite deck system may be fabricated without a corrugated decking member. FIGS. 1 and 2 illustrate corrugations 15A that form peaks and valleys along the length of the decking member 15. Located in and projecting upwardly from the upper horizontal joist members 13A and through the decking member 15 are the fasteners 10. A concrete slab 16 is then poured over the decking member 15, encasing the upper portion of the fasteners 10.

[0039] As illustrated, for example, in FIG. 3, the fastener 10 has an elongated shank 17 having a longitudinal axis A. The elongated shank 17 has an upper shank portion 19 and a lower shank portion or insertion member 34. The insertion member 34 has a diameter that is smaller than the diameter of the upper shank portion 19 and includes a tapered portion 40 and a knurled portion 18. The knurled portion 18 has a series of ridges and/or indentations. The knurl causes a welding effect between the fastener and the steel joist when the fastener is engaged in the joist. The knurled portion 18 can include, for example, a helix diamond knurl pattern as shown in FIGS. 3-4B. The upper shank portion 19 is an unknurled portion of the shank 17. Alternative knurled patterns include a spiral pattern 118 as shown in FIGS. 5A-6B. The spiral patterned knurl 118 introduces rotation during the driving of the fastener as disclosed in U.S. Pat. No. 8,449,237, which is incorporated by reference in its entirety.

[0040] Projecting from one end of the tapered portion 40 is a pointed tip 20 configured for driving into the decking member 15 and upper joist members 13A. The tapering of the insertion member 34, slows the fastener during the driving action into the joist members to eliminate over driving. The tapered portion 40 of the insertion member 34 is illustrated as having a rounded profile, as shown in FIGS. 3-4B. An alternative insertion member 134 embodied by the present invention as shown in FIGS. 5A-5B, has a stepped tapered portion 140. Another alternative insertion member 234 embodied by the present invention as shown in FIGS. 6A-6B has a straight tapered portion 240. In an embodiment, the stepped tapered portion 140, and straight shank 240 can have a sharper pointed tip 120 than the pointed tip 20 of the rounded tapered portion, of FIGS. 3-4B. Additionally, the sharper point of the stepped 140 and straight 240 tapered portions allows penetration through thicker steel bodies.

[0041] Embodiments of the present invention include any combination of the above knurled portions and tapered portions. For example, in an embodiment, a fastener 10 can include the rounded tapered portion 40 with a spiral pattern knurled pattern as shown in FIGS. 9 and 11.

[0042] Located at the end of the fastener 10 opposite the pointed tip 20 is a driving head 21. The driving head 21 is formed to engage the driving member 4 of the driving tool 2 which is capable of striking the top surface of the driving head end of the fastener. In an embodiment as shown in FIGS. 3 and 4A, 5A and 6A, the fastener 10 can be stricken at the end portion 31 of the shank 17, which has a chamfered driving head 23. The driving member 4 can be a driven by any of the many other well-known axial driving means. As shown in FIG. 2, the driving tool 2 drives the pointed tip 20 and knurled portion 18 of the fastener through the decking member 15, into the valleys of the corrugations 15A and through the upper horizontal joist members 13A.

[0043] An integral annular lower flange 26 is located between the insertion member 34 and the upper shank portion 19 of the fastener 10. The lower flange 26 has a diameter that is greater than the diameter of the shank 17 thereby providing a bearing surface 30 that contacts the joist members 13A and prevents over-driving or distortion of the joists.

[0044] In accordance with the present invention, the fastener 10 is selectively heat treated to a dual-hardness level so that the insertion member 34 has a relatively high degree of hardness to enable it to drive into the decking member 15 and the upper horizontal joist members 13A. The upper shank portion 19 of the fastener 10 is also heat treated, but to a lesser degree of hardness so that it remains relatively ductile and capable of resisting and transmitting the shearing forces of the concrete slab 16 in which it is encased. The shearing forces of the concrete slab 16 are generally directed left or right, relative to the decking member 15 and upper horizontal joist members 13A. In addition, the fastener 10 is uniquely constructed so that it correctly positions itself in and enhances interlocking with the concrete slab 16, in addition to establishing correct concrete slab cover.

[0045] During construction of the composite deck system 11, the insertion members 34 are driven through the valleys of the decking member 15 and through the upper horizontal joist members 13A. When each fastener 10 is driven, the bearing surface 30 of the lower flange 26 engages the decking member 15, thereby fastening the decking to the underlying joist members 13A. The lower flange 26 provides positive localized fastening. In particular, the lower flange 26 provides a positive stop to the fastener when the fastener is driven into the decking member 15 and the bearing surface 30 engages the decking member 15. As a result, the lower flange 26 ensures that the height of each fastener with respect to the horizontal joist member 13A is consistent, for uniform concrete cover requirements of the concrete slab 16 above the fastener. In addition, the lower flange 26 adds stability to the driven fastener within the concrete slab 16.

[0046] The bearing surface 30 of the lower flange 26 is substantially flat and joins the knurled shank portion 18 at chamfered surface or radiused angle 50. The radiused angle 50 increases the strength of the fastener in the area in contrast to sharp angles that can fracture when a heat treated fastener is driven by a powered driving tool. When the fastener is driven into place as shown in FIG. 2, the bearing surface 30 will securely fasten the top side of the decking to the underlying joist members 13A.

[0047] Additionally, the upper side of the lower annular flange 26 is smoothly radiused as at 32 to flare slowly from the angular flange to the upstanding shank 17. It is found that the curved or radiused junction is important to prevent cracking of the fastener when subjected to bending loads. The curved shape may also tend to distribute the shear forces, particularly when the concrete slab itself has a significant component loading the flange against the corrugated decking and joist members.

[0048] FIG. 3 illustrates a second or upper annular flange 27 located directly below the driving head 21, between the driving head and the upper shank portion 19 of the shank 17. The upper flange 27 is smaller in diameter than lower flange 26. The driving head 21 and upper flange 27 form a striking unit 29. The striking unit 29 has a profile that includes recesses 25 that define concrete interlocking areas, where the concrete is wedged between the driving head 21, flange 27 and end portion 31 of the shank 17. The recesses 25 allow concrete to form around the upper flange 27 and between sections of the striking unit, thereby creating an interlocking relationship between the fastener 10 and the concrete slab 16.

[0049] In an embodiment, the striking unit 29 can be integral with the upper shank portion 19 of the shank 17. In another embodiment, the striking unit 29 can be separate from the upper shank portion 19 of the shank 17 and attached thereto by external threads that threadedly engage internal threads on the inner surface of the upper shank portion 19. In further embodiment, the striking unit 29 can be separate from the upper shank portion 19 of the shank 17 and attached thereto by internal threads that threadedly engage external threads on the outer surface of the upper shank portion, similar to a post nut.

[0050] In an embodiment in which the striking unit 29 is separate from the shank 17, the striking unit can be attached to the shank before or after the fastener is driven into the decking member 15 by the driving tool 2. If the striking unit 29 is attached to the shank 17 after the fastener 10 is driven into the metal decking member 15, then the end portion 31 of the shank can be struck by the driving member 4 of the driving tool 2. In this regard, the end portion 31 of the shank 17 has a chamfered end 23 to prevent the end portion from becoming deformed when the fastener 10 is struck by the driving member 4. The chamfered portion 23 also helps the fastener 10 maintain its shape and not deform in embodiments where the striking unit 29 is integral with the shank portion 17 of the fastener.

[0051] When a shearing force acts on the upper portion of the fastener 10 that is encased in the concrete slab 16 (FIG. 2), the upper shank portion 19 of the fastener tends to bend, in a cantilever fashion, about the center of the lower flange 26, thereby pivoting the driving head 21 and the upper flange 27. As the upper flange 27 and the driving head 21 try to pivot in the concrete, the concrete surrounding the upper flange and the driving head responds with a restoring force couple. This restoring force couple is applied to the bottom surface 33 of the upper flange 27 opposite the shearing force and to the upper side of the upper flange 27 and driving head on the side of the shearing force. As a result, deflection of the fastener 10 in response to the shearing force is reduced. In this manner, the upper flange 27 enhances the structural interlocking between the fastener and the concrete slab. This same restoring force couple also has the effect of creating an upwardly directed force on the fastener at the underside of the upper flange 27, which tends to act through the insertion member 34 to reduce the deflection of the joist members 13A and web 14.

[0052] In carrying out the invention, the fastener 10 is heat treated to a dual-hardness level with a Drill-Flex® heat treating process developed by Elco Industries, Inc., Rockford, Ill. Specifically, the insertion member 34, 13, 234 is heat treated to a relatively high hardness so that it is capable of effectively tapping into the decking member 15 and the upper horizontal joist member 13A. The remaining portions of the fastener, i.e., the driving head 21, the upper shank portion 19, and the annular flanges 26 and 27, are heat treated to a lesser degree of hardness so that they remain relatively ductile and capable of resisting and transmitting the shearing forces of the floor or roof secondary structural members 12 to the main structural supports without failure. By way of example, the insertion member 34 is hardened to 54 minimum Rockwell C while the remaining portion of the fastener is hardened to 50%-70% of the insertion member 34.

[0053] As shown in FIGS. 5A-6B, 9 and 11, the flange can be in the form of a hex member 126 having a bearing surface 130. The hex shape allows for additional tightening of the fastener into the primary structural members 8.

[0054] Additionally, in further embodiments as shown in FIGS. 8, 9, 10 and 11, one end of the elongated shank 17 can have an externally threaded portion 45 that can threadedly engage internal threads on a post nut or cap (not shown). The post nut can have a diameter that is larger than the diameter of the threaded portion 45, thereby creating a recess between the post nut and the threaded portion. As with the striking unit 29, the recesses allow concrete to form around the post nut thereby creating an interlocking relationship between the fastener 10 and the concrete slab 16.

[0055] The driving tool can include, but is not limited to pneumatic tools, air powered tools, cordless battery-powered tools, nitrocellulose technology systems and gas fastening delivery systems. Further, a driving tool can include a powder actuated tool as shown in FIGS. 7A and 7B, which illustrate a configuration of the driving tool 2 with the fastener 10 within the tool body and after the fastener is driven from the tool.

[0056] From the foregoing, it will be apparent that the present invention brings to the art a new and improved fastener 10 for use in a lightweight or normal weight composite deck system 11 where the use of standard weld studs is precluded. In addition, the ability of the fastener 10 to resist and transfer shear forces in a composite deck system is enhanced over prior weld studs and many self-drilling studs by virtue of the dual-hardness levels embodied in the fastener and the provisions of the integral upper flange 27 which enhances interlocking between the fastener 10 and the concrete slab 16 and primary 8 structural members. Additionally, the installation of the powered fastener 10 is faster and therefore time-saving over the installation of weld studs.

[0057] While aspects of the present invention are described herein and illustrated in the accompanying drawings in the context of a fastener and tool, those of ordinary skill in the art will appreciate that the invention, in its broadest aspects, has further applicability.

[0058] It will be appreciated that the above description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. While specific examples have been described in the specification and illustrated in the drawings, it will be understood by those of ordinary skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. Furthermore, the mixing and matching of features, elements and/or functions between various examples is expressly contemplated herein, even if not specifically shown or described, so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise, above. Moreover, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular examples illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the teachings of the present disclosure, but that the scope of the present disclosure will include any embodiments falling within the foregoing description.