Patent Application
20090178352
This disclosure relates to a structural member constructed for strength in tension and compression. More specifically, the structural member includes a composite body with an internal cable for added benefits.
Load bearing structural members often have elongated bodies, and must be light-weight for certain construction projects. Applications include structures that must be constructed by hand, such as in remote or military applications, such as for cranes assembled on oil rigs. As such, certain structural members must not be heavy while still being able to handle appropriate loads and forces.
Aluminum extrusion pieces, such as shown in U.S. Pat. No. 6,561,571, have been used for structural members requiring strength in compression and axial forces. Aluminum is known to form many hard, light and corrosion-resistant alloys for use as structural members.
Also, U.S. Pat. No. 6,539,679 discloses a light-weight structural member with a strength-reinforcing flat steel strap. The steel strap extends along the length of the structural body, and it transfers load outwardly toward the opposing portions of the structural body. Anchor plates at opposing ends of the structural body hold the strap in tension. The pre-tensioned strap is secured in tension to opposing ends.
Next, various cables have previously been used in tension, but not in the same structural member arrangement of the present disclosure.
The present disclosure provides a light-weight composite structural member. The composite structural member is light-weight while providing enhanced benefits for resisting a combination of tension, compression, and buckling forces.
A composite structural member includes an elongated body having one or more internal recesses with a tensioned cable in one recess or a series of recesses. End pieces on each end of the elongated body secure the cable to the body. Each end piece may include an aperture and adjustable means to secure the cable in tension. The cable may also provide an additional safety factor for the structural member.
The above-mentioned and other features of this disclosure and the manner of obtaining them will become more apparent, and the disclosure itself will be best understood by reference to the following descriptions of structural members taken in conjunction with the accompanying figures, which are given as non-limiting examples only, in which
The exemplifications set out herein illustrate embodiments of the disclosure that are not to be construed as limiting the scope of the disclosure in any manner. Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.
While the present disclosure may be susceptible to embodiments in different forms, the figures show, and herein described in detail, embodiments with the understanding that the present descriptions are to be considered exemplifications of the principles of the disclosure and are not intended to be exhaustive or to limit the disclosure to the details of construction and the arrangements of components set forth in the following description or illustrated in the figures.
As shown in
The elongated body 12 can be preloaded to resist compression or lateral forces. The elongated body 12 preferably includes internal spaced walls 22 for added reinforcement and strength. As shown in the drawings, certain internal walls 22 can be perpendicular to the outer surface 24 of the elongated body 12. Additional internal walls 26 can be concentric with or parallel to the outer surface 24 of the elongated body 12.
The elongated body 12 preferably has a plurality of internal recesses 20 extending from the first end to the second end of the body 12 and that are capable of enclosing a plurality of internal cables 18. As shown in
The elongated body 12 is preferably preloaded extruded aluminum with a cover mantle 30, such as carbon fiber, S glass fiber, a thin swaged layer of steel or Kevlar, on the outer surface 24. The cover mantle 30 can additionally assist with resisting forces of compression and buckling.
The end pieces 14 and 16 are preferably end caps that preferably completely cover each end of the elongated body 12. The end pieces 14 and 16 can be respectively secured to each end of the elongated body 12 by a variety of means, including welding, friction fit, cable tension or fastening plates 32. As shown in
As such, the end pieces 14 and 16 are respectively connected on each end of the elongated body 12 by fastening plates 32 fastened to head plates 34 that pass through each end piece 14 and 16. An end portion of the elongated body 12 is secured between the fastening plates 32 and the head plates 34. Preferably, the fastening plates 32 and head plates 34 are friction fit with the elongated body 12 and secured, such as by a bolt 36. The fastening plates 32 and head plates 34 may be clamped and loaded together on a portion of the elongated body 12 so hard that they should not move under normal load. The head plate 34 passing through the end piece 14 and 16 transfers force on the end pieces 14 and 16 to the outer wall 24 of the elongated body 12 and prevents rotation of the head plate 34 and/or end pieces 14 and 16 with respect to the body 12.
The end pieces 14 and 16 preferably cover each end of the elongated body 12 and may include a functional piece 38, such as a socket, collar or pin holder for use in making a connection with another structure. The end pieces 14 and 16 may have an aperture 40 capable of serving as a cable hole through which each end of the cable 18 are connected to each end piece 14 and 16. Preferably, at least one cable aperture 40 includes a means for preloading the cable with tension 42, such as including an incised threaded rod, i.e. a helically advancing threaded screw and washer. The means for preloading the cable 42 includes various screws and washers. A cable head 44 may be included that is secured to an end of the cable 18 as part of the means for preloading the cable 42. Other means to fasten and preload the cable include the cable being threaded on a small pulley with a rack and pawl to load the cable 18 and keep it from unwinding.
The cable 18 is connected to each end piece 14 and 16 and can be adjusted as a pretensioned cable fitted between the end caps 14 and 16. The cable 18 can be stretched under pretension and affixed to end caps 14 and 16 at both ends of the structural member 10, passing inside the internal recess 20.
In another embodiment shown in
Per the example shown in
In the center of the four pieces 50, an insert 60 can be wedged as shown in
For each embodiment, the components can be made of any suitable material. The elongated body 12 is preferably metal, ideally aluminum, but could be made of plastic or other materials. The cable 18 can be a wire rope formed from steel or a fiber rope, and may be cord formed from various materials.
The multipurpose structural member 10 can be adapted for various uses. While functional pieces 38 may dictate uses for the composite structural member 10, the member 10 may be used in a variety of applications as struts, braces, support, props and beams for various structures as tension or compression components. The composite structural member 10 provides benefits for resisting a combination of tension, compression, and buckling forces.
This disclosure has been described as having exemplary embodiments and is intended to cover any variations, uses, or adaptations using its general principles. It is envisioned that those skilled in the art may devise various modifications and equivalents without departing from the spirit and scope of the disclosure as recited in the following claims. Further, this disclosure is intended to cover such variations from the present disclosure as come within the known or customary practice within the art to which it pertains.
