Patent Application
20070241226
Reels or spools of various sizes and configurations are used for storing and transporting flexible materials of the type that can be wound around a cylindrical core. In the industrial setting, reels are used to store wire and cable product of various gauges. Such reels typically comprise a cylindrical core, commonly referred to as a barrel or drum, about which the product is coiled. To protect the product during shipment and handling, the barrel is attached at either end to a disc-shaped flange.
In order to reduce shipping costs, reels are commonly transported in the form of their disassembled components, i.e., detached barrels and flanges. Reels that can be readily assembled from their components are known as “knockdown” reels. Knockdown reels must be capable of being assembled from their components quickly and easily, yet such reels must also have the structural strength to withstand several different types of stress.
Since the product stored on a reel is often heavy and bulky, it exerts considerable axial force outward on the flanges. Reels are often lifted by one of the flanges, so the connections between the flange and the barrel must be able to support the full weight of the loaded reel. When the wire or cable is being wound or unwound on the reel, it exerts a large centripetal/centrifugal force on the barrel, tending to collapse the barrel during the winding process and tending to split the barrel open during the unwinding process. When a reel is dropped during transport or handling, a sudden inward axial force can impinge upon one or both of its flanges, as well as upon the flange-barrel connections.
In addition to these daunting structural challenges, marketplace realities dictate that reels be made of the least expensive materials available. It is a great advantage, therefore, to retain the option of fabricating a reel using a variety of materials, and to thereby be able to select the least expensive materials based on prevailing market conditions.
When one surveys the prior art in this field, however, one does not find a design which addresses each of the three identified requisites for an optimal knockdown reel: (a) rapidly assemblable from its components, (b) structural strength to withstand lifting, winding/unwinding and/or dropping, (c) flexibility in selection of component materials.
In the prior art, we find two basic types of knockdown reels. The first type are those that are designed to be fabricated exclusively or primarily with plastic and/or metal components. In these designs, the attachment of the barrel to the flanges is secured by locking mechanisms consisting of a flexible male member which temporarily bends or deforms to fit into a conjugate female member. In order to lock into place within the female member, the male member must be made of a resilient material which, after deformation within a certain range, will resume its original configuration.
In the prior art, there are several examples of knockdown reels utilizing resilient locking mechanisms: Hacker, U.S. Pat. No. 3,552,677 (flexible “stems” #52 projecting from barrel ends snap into “apertures” #56 in flanges, FIGS. 3 and 6); Crellin, U.S. Pat. No. 3,785,584 (yieldable “projections” #42 from barrel ends engage resilient “tongues” #22 in flanges, FIGS. 3 and 4); Campbell, U.S. Pat. No. 3,822,841 (flexing “latch members” #24 from barrel ends insert into “openings” #40 in flanges, FIGS. 3, 5, 6 and 12); McCaffrey, U.S. Pat. No. 4,903,913 (yielding “detents” #80-85 from barrel ends fit into “openings” #70-74 in flanges, FIGS. 4 and 5); Campbell, U.S. Pat. No. 5,575,437 (flexing “latch fingers” #24 from barrel ends snap into “openings” #40 in flanges, FIGS. 2, 8 and 10).
Leunig, U.S. Pat. No. 4,471,919, uses flexible barrel halves (#18 and 20) with a resilient hinge #22 to interlock with a camming element #52 in the flange (FIG. 2-4). In Bulman, U.S. Pat. No. 5,743,486, the barrel threads into the flange and is locked in place by mating resilient annular locking rings in the barrel #14 and flange #19 (FIGS. 6 and 7).
All of the foregoing knockdown reel designs depend on the resilient qualities of plastic or metal components which yieldingly fit together. This presents an economic disadvantage insofar as the use of less expensive wooden, composite board and/or cardboard components is thereby precluded. Another disadvantage of these designs is their vulnerability to inward axial stress on the flanges, such as occurs when a reel is dropped. Such inward forces will tend to compress the flange against the end of the barrel, potentially causing the resilient plastic/metal male member of the locking mechanism to deform and relax its grip within the female member. To the extent such designs have segmented flexible barrels using resilient interlocks (e.g., Leunig, FIG. 3, #30 and 32), they are also vulnerable to outward radial stress on the barrel during the unwinding process.
While there are knockdown reel designs that avoid the need for a resilient locking mechanism, e.g., Campbell, U.S. Pat. No. 3,940,085, and Witwer et al., U.S. Pat. No. 5,806,788, they depend upon threaded bolts (Campbell #32, FIG. 2; Witwer #54, FIG. 2) to attach the barrel to the flanges, thus making the assembly process excessively laborious and time consuming.
Therefore, the prior art falls short of fulfilling the three criteria for an optimal breakdown reel design, with respect to economical selectability of the most component materials, structural integrity under inward axial and outward radial stresses, and speed of assembly.
The present invention represents a significant improvement over the prior art with respect to its ability to use inexpensive wooden, composite board and/or cardboard components. A pair of flanges which are disc-shaped with an inner surface and an outer surface are fabricated of plywood or any other strong, durable composite board, such as hardboard or oriented strand board. A barrel can be either an integral barrel or a split-barrel. The integral barrel comprises one cylindrical core, while the split-barrel comprises two semi-cylindrical half-cores. In either mode, the barrel is made of cardboard tubing reinforced at either end by collars made of plywood, composite board or laminated cardboard. In the preferred embodiment, each collar fits within interior annular routing on the inner surface of the corresponding flanges. Alternately, the collar may be recessed within the barrel, such that only the cardboard tubing fits within the interior annular routing. Multiple apertures in the collar are aligned with matching fastening holes within the interior annular routing in the flange. The fastening holes extend through the flange to the outer surface of the flange, where the fastening holes emerge within exterior annular routing.
The exterior annual routing of the flange is formed to accept an annular fastener, which is made of rigid metal or plastic. The annular fastener comprises a flat annular ring to which are riveted, at equally spaced intervals around the ring, multiple projecting fingers, each having a tip and a base. The number of fingers corresponds to the number of fastening holes in the flange. Each finger comprises a composite of multiple segments, which are cylindrical or frustrum-shaped. In the preferred embodiment, the segments all have the same diameter, which is slightly less than the diameter of the fastening holes in the flange. Alternately the segments can decrease in diameter from the base to the tip of the finger, with the segment at the tip of each finger having a diameter slightly less than the diameter of the fastening holes in the flange. In another alternate embodiment, one of the fingers is longer than the others in order to serve as a guide in aligning the fastening holes of the flange with the apertures of the collar.
A knockdown reel according to the present invention can be quickly assembled by attaching one flange to each end of the barrel. The flanges are attached to the barrel one at a time by first inserting the collar (in the case of the integral barrel) or collars (in the case of the split barrel) into the interior annular routing and aligning the apertures of the collar(s) with the fastening holes. The fingers of the annular fastener are then inserted into the fastening holes through the exterior annular routing, and pressure is applied to the ring to drive the fingers through the flange and into the apertures of the collar(s). Upon the completion of this operation, the ring is secured within the exterior annular routing, and the collar(s) of the barrel are secured within the interior annular routing.
Since the annular fastener is inserted through the outer surface of the flange, it is relatively invulnerable to loosening by inward axial forces on the flange, such as occur when the reel is dropped. Due to the configuration of the segments comprising the fingers of the annular fastener, the fingers are retained tightly within the collar(s) of the barrel and can withstand outward axial forces on the flange, such as occur when the reel is lifted. Because the ring of the annular fastener interconnects all of the fingers, the fingers serve to reinforce the barrel with respect to centripetal radial stresses tending to collapse its core, as well as centrifugal radial stresses tending to open its core (in the case of the integral barrel) or separate its half-cores (in the case of the split barrel).
Therefore, the present invention fulfills the three identified objectives with respect to an optimal breakdown reel. It retains the optional economical use of multiple component materials; it is easily and quickly assembled; and it is structurally sound under the four probable stress modes: axial inward, axial outward, radial centripetal and radial centrifugal.
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The flanges are disc-shaped panels preferably having a thickness of 5/16″ to ⅜″. The flanges are fabricated of plywood or any other strong, durable composite board, such as hardboard or oriented strand board. As shown in
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In an alternate embodiment, the collar(s) 15 are recessed within the barrel 11 at the same depth as the depth of the interior annular routing 20, such that only the tubing 14 fits within the interior annular routing 20, while the collar(s) 15 engage the inner surface 17 of the flange 12 within the inner diameter of the interior annular routing 20.
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The ring 24 of the annular fastener 23 is dimensioned to fit snuggly within the exterior annular routing 22. In the preferred embodiment, the ring 24 is 1/32″ thick and the exterior annular routing is 1/16″ deep.
In an alternate embodiment, the exterior annular routing 22 is not present, and the annular fastener 23 engages the outer surface 18 of the flange 12 with the fingers 25 projecting into the fastening holes 21. In another alternate embodiment, one of the fingers 25 is longer than the others in order to serve as a guide for aligning the fastening holes 21 with the apertures 16 of the collar(s) 15. In yet another alternate embodiment, plastic sleeves (not shown) are inserted into the apertures 16 such that, when the flange 12 is attached to the barrel 11, the plastic sleeves extend into the fastening holes 21. The interior of each of the sleeves is formed to correspond conjugately to the profile of the segments 28 of each finger 22 of the annular fastener 23, such that when the finger is inserted into the sleeve, the sleeve expands within the fastening hole 21 and the aperture 16 and thereby locks the annular fastener in place.
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The present invention, therefore, is readily and speedily assemblable from five or six component parts which can be fabricated of plywood, composite board and/or cardboard, except in the annular fastener 23. The annular fastener 23 provides structural strength under both inward and outward axial stresses on the flanges 12, as well as under both centripetal and centrifugal radial stresses on the barrel 11.
While the current invention has been described in some detail with reference to certain currently preferred embodiments, other embodiments are feasible and will readily suggest themselves to those skilled in the art. Therefore, the spirit and scope of the appended claims are not limited to the description of the preferred embodiments contained herein.
