The present invention relates to fasteners and, more particularly, a fastener including a swage indicating collar.
Two-piece swaged fasteners, commonly referred to as lockbolts, are used to secure a plurality of workpieces together. Typically swage-type fasteners include a pin member having lock grooves and a swage collar adapted to be swaged into the lock grooves of the pin member by a fastener installation tool. The collar may include a built-in washer or a flange, which supports high clamp load in workpieces made from soft steels or aluminum without embedment. In many applications, the collar is installed against medium to high strength steel, which do not require as much bearing area as required for soft steels and aluminum. The collar may also include raised inspection dots extending from the collar flange that are marked by the installation tool to visually indicate a complete swage of the collar and installed properties. What is needed is a swage collar that utilizes less material, while providing adequate bearing area and a visual indication of a complete swage.
In an embodiment, a swage collar includes a shank having a first end, a second end opposite the first end, and an outside diameter; a flange extending circumferentially from the first end of the shank and having a outer diameter; and a transition step formed at a location where the first end of the shank transitions to the flange, wherein the swage collar is adapted to be swaged, and wherein when the swage collar is swaged, the transition step is deformed from an undeformed state to a deformed state wherein the transition step is blended with the outside diameter of the shank and the outer diameter of the flange.
In an embodiment, the transition step is substantially linear in its undeformed state. In an embodiment, the transition step is oriented at an angle from a longitudinal axis of the swage collar. In an embodiment, the angle is about 90 degrees. In an embodiment, the angle is about 120 degrees. In an embodiment, the angle is about 135 degrees. In an embodiment, the angle is within a range of about 90 degrees to about 135 degrees.
In an embodiment, when the transition step is in its deformed state, the transition step includes a curved portion. In an embodiment, the curved portion includes a radius of curvature. In an embodiment, the radius of curvature is within a range of about 0.476 inch to about 0.714 inch. In an embodiment, the shank includes a bore extending from the first end to the second end of the shank, an inner surface defined by the bore, and a fit-up tab extending from the inner surface. In an embodiment, the swage collar further comprises at least one material selected from the group consisting of low carbon steel, annealed low carbon steel, and unannealed low carbon steel. In an embodiment, the swage collar is as-headed.
In an embodiment, a fastener includes a pin member having an elongated shank portion which terminates at one end in a head and includes a threaded portion having a plurality of threads with lock grooves; and a swage collar including a shank having a first end, a second end opposite the first end, and an outside diameter, a flange extending circumferentially from the first end of the shank of the swage collar and having a outer diameter, and a transition step formed at a location where the first end of the shank transitions to the flange, wherein the swage collar is adapted to be swaged onto the lock grooves of the threaded portion of the pin member, and wherein when the swage collar is swaged, the transition step is deformed from an undeformed state to a deformed state wherein the transition step is blended with the outside diameter of the shank of the swage collar and the outer diameter of the flange.
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In an embodiment, the swage collar 14 includes an internal fit-up tab 42 extending from an inner surface 44 of the collar 14. In an embodiment, the fit-up tab 42 includes a single thread, such as that shown in U.S. Pat. No. 4,867,625 to Dixon, which is incorporated by reference herein in its entirety. In an embodiment, the fit-up tab 42 is positioned proximate to the second end 34 of the shank 30 of the swage collar 14. In another embodiment, the fit-up tab 42 is positioned proximate to the first end 32 of the shank 30 of the swage collar 14. The purpose and function of the fit-up tab 42 shall be described below. In another embodiment, the swage collar 14 need not include the fit-up tab 42.
In an embodiment, the swage collar 14 is made of low carbon steel. In another embodiment, the swage collar 14 is made from unannealed low carbon steel. In another embodiment, the swage collar 14 is made from annealed low carbon steel. In another embodiment, the swage collar 14 is “as-headed” and does not require thermal processing, as disclosed and described in aforesaid U.S. Pat. No. 7,293,339 to Mercer et al. As employed herein, the term “as-headed” refers to a collar which is strain hardened, for example, from cold working, rather than changing hardness using a thermal process (e.g., quench and tempering; stress relieving; etc.).
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In an embodiment, the pull grooves 28 of the pin member 12 are adapted to be gripped by matching teeth of chuck jaws of a fastener installation tool having a swage anvil (not shown in the Figures). In an embodiment, the fastener installation tool may consist of the tools disclosed and described in aforesaid U.S. Pat. No. 7,293,339 to Mercer et al. In an embodiment, the swage anvil of the tool is adapted to engage the swage collar 14 and apply a relative axial force between the collar 14 and the pin member 12, and to move over the collar 14 and swage it into the lock grooves 24 of the pin member 12 (not shown in the Figures). In an embodiment, during the installation process, the transition step 40 of the collar 14 (shown in
It should be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims.
This application is a Section 111(a) application relating to and claiming the benefit of commonly owned, co-pending U.S. Provisional Patent Application Ser. No. 61/594,061 entitled “SWAGE INDICATING COLLAR,” filed Feb. 2, 2012, the entirety of which is incorporated herein by reference.
Number | Date | Country | |
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61594061 | Feb 2012 | US |