1. Field of the Invention
This invention relates to rods for reinforcing ductwork, and more particularly, to a reinforcing rod which is designed to enable a faster and easier installation into ductwork.
2. Description of the Related Art
Duct work, such as air conditioning ducts, are often made of a metallic material such as galvanized steel. These ducts require reinforcement to provide support to the ducts and to prevent them from bulging or buckling. One way that such reinforcement has been provided has been to surround the outside of the duct with an external reinforcement.
Another method that has been developed to reinforce air conditioning ducts and the like has been to position reinforcing rods or conduits on the interior of the ducts. In one previously known method, the length of the rod is threaded, and the rod is inserted into opposing holes in the walls of the duct and secured to these walls using a nut and washer configuration. One problem with this type of reinforcement is that the rods are necessarily longer than the distance between the walls of the duct, making it difficult to install the rods. This becomes especially problematic as the size of the duct decreases.
One previously known method to overcome this problem is to provide a conduit having a length corresponding to the distance between the opposing sides of the duct. Each end of the conduit is internally threaded, using an internally threaded nut press fit at each of the conduit. Then, by lining up the conduit with the opposing holes in the duct walls, bolts may be inserted from the outside of the duct through the internally threaded ends to secure the conduit within the ductwork. However, these conduits are difficult to align with the holes for insertion of the bolts. Moreover, these inserts can be pulled out of the conduits with a certain degree of force, thereby making the reinforcement ineffective.
Accordingly, what is needed is a method and apparatus for easily and quickly reinforcing an air conditioning duct and the like.
In one embodiment, a reinforcement is provided comprising a conduit having a first end and a second end. A pair of plugs is insertable into the first and second ends of the conduit. Each of the plugs has a groove extending along the circumference of the plug, and the plugs are crimped inside the conduit along the grooves. Each of the plugs may have a threaded end extending out of the plug and being retractable into said plug. Alternatively, each of the plugs may have an internally threaded opening extending at least partially through the plug. The reinforcement may then further comprise a bolt insertable into the threaded opening.
In another embodiment, a plug for insertion into an end of a conduit is provided. The plug comprises a body portion having a first end and a second end and an opening extending from the first end at least partially through said body portion. A groove extends at least partially along the circumference of the body portion, the groove adapted to receive a crimping force applied to the conduit when the plug is inserted into the end of the conduit. The plug may be internally threaded, or may further comprise a threaded member retractably positioned within the opening.
In another embodiment, a reinforced duct work is provided. The duct work has opposing surfaces, each of the surfaces having a hole therein aligned with an opposing hole. A conduit is provided having a first end and a second end, and has a plug inserted into each end thereof. Each plug has a groove extending along at least a portion of the plug, and the conduit is crimped to the plugs along the grooves. The conduit is positioned such that the first and second ends are aligned with the holes and the conduit is secured to the surfaces of the duct work. In one embodiment, the conduit may be secured to the surfaces of the duct work by bolts inserted through the holes in the duct work and into internally threaded holes in each plug at each end of the conduit. In another embodiment, each plug has a retractable threaded end which extends through one of the holes when the conduit is aligned therewith, and the conduit may be secured by nuts tightened over the retractable threaded ends against the surface corresponding to the holes.
In another embodiment, a method for reinforcing duct work is provided. The duct work has opposing surfaces, each of the surfaces having a hole therein aligned with an opposing hole. The method comprises providing a conduit having a first end and a second end, wherein the conduit has a plug inserted into each end thereof, each plug having a groove extending along at least a portion of the plug, and wherein the conduit is crimped to the plugs along the grooves. The conduit is positioned such that the first and second ends are aligned with the holes, and the conduit is secured to the duct work. In one embodiment, bolts may be inserted through the holes in the duct work and into internally threaded holes in each plug at each end of the conduit. The bolts are tightened within the plugs to secure the conduit to the duct work. In another embodiment, the plugs each have a retractable threaded end which extend through one of the holes when the conduit is aligned therewith. Nuts are tightened over the retractable threaded ends against the surface corresponding to the hole to secure the conduit to the duct work.
Preferred embodiments of this invention relate to reinforcement of duct work (e.g., for air conditioning ducts), and more particularly, to conduits used for reinforcing duct work. In particular, certain embodiments describe plugs for insertion into the ends of the conduits in order to provide for easier insertion into the duct work and/or a more secure connection and reinforcement.
Provided on the shaft 28 is a pin 30, which extends into an L-shaped cutout 26 provided in the wall of the body portion. The spring within the body portion presses against the bottom of the shaft 28, forcing the threaded end 20 outward relative to the head 22, and correspondingly, positioning the pin at the top of the “L.” Thus, the pin 30, when contacting the top of the L-shaped cut-out, prevents the threaded end 20 and the shaft 28 from exiting the body portion 24, and also prevents rotation of the threaded end 20.
It will be appreciated that although the plug 18 has been described as containing a locking mechanism 26, the plug may also be provided without such a locking mechanism. In such an embodiment, the plug 18 is in a relaxed position when the threaded end 20 is fully extending out of the body portion 24, as shown in FIG. 2C. Because of the spring inside the body portion 24, when a force is placed against the threaded end 20, causing the threaded end to move into the body portion, the threaded end will be biased to move back to its relaxed position unless the force on the threaded end is maintained.
Provided inside the cavity of the body portion 24 are a spring 48 (shown in
To install the reinforcing conduit into the duct 10, the conduit 32 is inserted between the opposing surfaces 12, 14 of the duct 10. The threaded ends 20 of the plugs in the conduit, when pressed against the walls of the duct, are forced into the body portions 24, thereby shortening the length of the conduit with the plugs. This enables the conduit to be moved around more easily within the duct. The conduit 32 is preferably moved within the duct 10 until the threaded ends 20 encounter the opposing holes 16 of the duct. When the threaded ends 20 are free to unretract from the body portions 24 (i.e., the embodiment of
Alternatively, if the threaded ends are locked such as shown in
It will be appreciated that when installing conduit as described above, it is often advantageous to install one end of the conduit 32 first into a hole 16, with the threaded end 20 at that one end already unretracted, and then simply orienting the conduit such that the other threaded end 20 encounters the opposing hole 16. In this embodiment, as the other threaded end 20 is brought towards the opposing hole 16, the end 20 will likely retract into the conduit as the force of the wall nearby the opposing hole 16 presses the threaded end 20 into the body portion 24.
In another embodiment, it will be appreciated that a conduit may be provided in which only one end has a retractable threaded end, while the other end has an threaded end which always extends out of the end of the conduit.
The embodiments described also improve over the prior art in which threaded reinforcement rods are used in that reinforcing conduits as described herein are stronger than threaded rods and therefore are more resistant to buckling.
It will be appreciated that the plugs 58 and 60 can be made from a variety of suitable materials. For example, certain preferred materials include, but are not limited to, nylon, steel and aluminum. Desired materials may be selected based on the superior pull out strength offered by the crimped plugs. For example, a nylon plug which has been injection molded desirably provides a pull out strength of about 800 to 1200 lbs. A steel plug desirably provides a pull out strength of about 3200 to 5000 lbs. An aluminum plug desirably provides a pull out strength of about 1500 to 2500 lbs. It will also be appreciated that to provide increased pull out strength, more than one groove 62 may be provided on the plugs.
Crimping of the plugs 58 and 60 to the conduit can preferably be accomplished using any suitable crimping device. One such device is shown in
Provided on the shaft 76 is a pin 80, which extends into a slot 82 provided in the wall of the body portion. The spring within the body portion presses against the bottom of the shaft 76, forcing the threaded end 72 outward, and correspondingly, positioning the pin at the top of the slot 82. Thus, the pin 80, when contacting the top of the slot, prevents the threaded end 72 and the shaft 76 from exiting the body portion 74, and also prevents rotation of the threaded end 72.
Near the top of the slot 82, a passageway 84 is provided to allow the threaded end 72 and the shaft 76 to exit the tubular body portion 74. An operator can remove the threaded end from the body portion 74 by pressing slightly down on the threaded end 72, and turning the threaded end (in the embodiment shown, counter-clockwise) such that the pin 80 follows the passageway 84. The passageway 84 turns up toward the top end of the body portion 74, which allows the threaded end to be removed.
The tubular body portion further includes a groove 86 near the end of the plug opposite the threaded end 72. This groove, as with the embodiments of
Although the embodiments described herein relate to reinforcement of air conditioning ducts, it will be appreciated that the preferred embodiments of the present invention may be used in other applications as well. It will be appreciated that the plugs 18 described above may be used in applications with and without the conduit 32. For example, a conduit having plugs with retractable threads may be used for inserting shower curtain rods. In another example, plugs with retractable threads may be used for furniture legs. In such an embodiment, in fact, the retractable portion of the plug need not be threaded. Other possible uses include hangers between doors and inside closets, and clothes hangers in automobiles.
It should be understood that certain variations and modifications of this invention will suggest themselves to one of ordinary skill in the art. The scope of the present invention is not to be limited by the illustrations or the foregoing descriptions thereof, but rather solely by the appended claims.
This application claims the benefit of U.S. Provisional Application No. 60/346,526, filed Jan. 8, 2002, the entirety of which is hereby incorporated by reference.
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Number | Date | Country | |
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20030127146 A1 | Jul 2003 | US |
Number | Date | Country | |
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60346526 | Jan 2002 | US |