Abstract:
A lightweight, collapsible, readily repairable, minimum thickness reel for cable, conduit, tubing or the like and the components of which are preferably molded of synthetic resin material. The end flanges of the reel each have a flat inner surface and a cellular outer surface for decreased weight. Molded, foldable ribbed tubing support units are interposed between the inner surfaces of the end flanges for receiving and supporting cable, conduit or tubing wound therearound when the support units are extended. The planar, inner surfaces of the end flanges have recesses for complementally receiving the rib portions of the leg segments of respective support units so that when the reel is in its collapsed condition the reel is not substantially thicker than the combined thickness of the side by side end flanges. The end flanges are molded of a synthetic resin material in a mold which receives pre-molded leg segments with a release agent thereon which results in concomitant forming of the recesses for the folding leg segments of the support units. A blowing agent may be incorporated in the resin in which the flanges are molded so that a relatively thin, tough, abrasion resistant skin is formed while the interior of the wall structure of the flange is of decreased density.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates to a lightweight, collapsible reel for supporting cable, conduit or tubing wound therearound and especially to a reel collapsible to a thickness no greater than approximately the thickness of the two side by side circular end flanges of the reel. The components of the reel are especially adapted for fabrication of synthetic resin material which results in an extremely lightweight reel that retains its load bearing properties and characteristics after repeated in-field use of individual reels.  
         [0003]     Collapsible reels for supporting products such as elongated stretches of a cable, conduit or tubing wound around the core of the reel are known but have not heretofore gained widespread recognition in the field. Although deficiencies in marketing of past collapsible reels may have been a contributing factor in limited customer demand for prior reels, the inability of such reels to fully collapse and the excessive weight of the reels even when collapsed no doubt has been a limiting deterrent to widespread adoption and use.  
         [0004]     2. Description of the Prior Art  
         [0005]     Brown, in U.S. Pat. No. 3,791,606, illustrates a cable spool said to be collapsible but as illustrated in FIG. 4 of the patent drawings, folding of the central bar or leg segments 13 results in collapse of the reel such that there is still a space between opposing flanges 5 that substantially exceeds twice the width of one of the flanges 5. Thus, Brown in the &#39;606 patent does not disclose or suggest a collapsible lay flat reel. Brown teaches the provision of a spool in which the end flanges are movable toward one another but opposed margins of the foldable leg segments form a V when folded which limits collapse of the reel flanges.  
         [0006]     Similarly, in Culp U.S. Pat. No. 5,649,677, the patentee provides a collapsible spool having a plurality of foldable arms 16 which fold into a state of maximum collapse, as illustrated in FIG. 8. The overall thickness of the reel when collapsed is substantially greater than twice the thickness of one of the end flanges.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides a lightweight, collapsible reel for cable, conduit or tubing in which a pair of opposed, relatively thin, generally circular, coaxially end flanges of substantially equal diameter are interconnected by at least three foldable cable, conduit or tubing support units. The reel, when fully collapsed, is no thicker than twice the thickness of each individual end flange. The support units, which each include a pair of hingedly interconnected end-to-end leg segments that cooperate in their fully extended, straight-line positions, to present a generally triangular cage internal of the space between the flanges for wrapping of cable, conduit, tubing or the like around the support units.  
         [0008]     The end flanges and support units are designed and especially adapted to be individually molded as one-piece from synthetic resin material. Preferably, the flanges in the leg segments of the support units are molded of a synthetic resin material in prefabricated molds utilizing a resin such as polypropylene containing a conventional blowing agent so that a thin, relatively tough, abrasion resistant outer skin is formed from compaction of the resin at the surface of the part while the lower density resin produced by the blowing agent serves as an internal support for the skin.  
         [0009]     In order to minimize the overall weight of the reel without sacrifice of its utility and strength characteristics, each of the unitary flanges has an inner relatively flat face, and an outer cellular face defining a plurality of weight saving spaces. In a preferred embodiment, the outer portion of each of the flanges includes an outer annular band of end-to-end rectangular pockets, an intermediate annular section of web defining trapezoidal spaces, and an innermost central section of generally polygonal areas.  
         [0010]     The leg segments of the support units are preferably molded to define a series of elongated, side by side ribs which increase the beam strength of the individual segments while saving weight. The flanges are provided with a series of elongated recesses located to complementally receive the rib portions of respective leg segments of the support units. When the reel is collapsed by folding of the support units, the rib portions of the leg segments of each support unit, which face outwardly relatively, are fully received in respective recesses in the flanges so that the inner faces of the flanges move into interengaging, side by side relationship. The result is a reel when collapsed that is no thicker than the thickness of the side by side flanges.  
         [0011]     The leg segments of respective support units are pivotally interconnected by a pin. Individual leg segments, which are all of identical construction, are all molded separately. Each of the ribbed leg segments has openings at opposite ends thereof. Pivot pins are inserted in the openings in one end of three leg segments. The three leg segments with the inserted pins, are then placed in a mold for a respective end flange with the pivot pins located 120° apart in spaced relationship as required for formation of the triangular cable, conduit or tubing cage to be defined by the support units. The leg segments with the inserted pins are located in the mold such that the ribbed surfaces face inwardly of the mold cavity. The mold also incorporates cavity defining surfaces for the cellular outer face of each of the molded flanges. By molding the individual leg segments along with the flange itself, the ribs of the leg segments form indentations or recesses in the inner surfaces of the flange so that the leg segments which are pivotally connected to the flange are inherently complementally received in the formed recesses. It is to be understood in this respect that a mold release agent is applied to the ribbed surfaces of the leg segments that are pivotally joined to a respective flange so that upon removal of the molded part from the mold, the leg segments that have been molded in place may readily be pivoted to their open, outwardly extended positions.  
         [0012]     Upon completion of two molded flanges with incorporated leg segments, the leg segments of both flanges are extended outwardly and pivot pins inserted within aligned holes in what becomes end-to-end leg segments of respective support units.  
         [0013]     The end flanges are provided with central openings which are coaxial in the completed reel so that a guide rod or pipe may be inserted through the aligned openings to guide or support the reel as a cable, conduit or tubing is unwound from the expanded reel.  
         [0014]     An important advantage of the present collapsible reel is the fact that manufacture of the reel of synthetic resin material as explained permits recycling of the reel at the end of its useful life, which in most instances should be at least the order of fifty cycles of use. Another advantage is the minimal thickness of a fully collapsed reel, which is {fraction (1/6)}th to {fraction (1/7)}th that of a conventional reel. The no more than 2× flange thickness of each collapsed reel results in significant savings in return transportation costs of empty reels in collapsed condition from a space standpoint, in that a significantly larger number of reels may be transported in the space that would have been taken up in the transport vehicle by conventional reels. In addition, minimization of warehousing space required for empty reels provides significant cost savings. The collapsed reels are much easier to handle and maneuver because of the decreased weight as compared with conventional plywood reels. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is an isometric view of a collapsible reel constructed in accordance with the preferred concepts of this invention and showing the reel with cable, conduit or tubing wound therearound and supported by a conventional reel stand;  
         [0016]      FIG. 2  is an expanded isometric view of the collapsible reel;  
         [0017]      FIG. 3  is an isometric view of the collapsible reel minus the cable, conduit or tubing shown in  FIG. 1  and illustrated without support of a reel stand;  
         [0018]      FIG. 4A  is a generally schematic elevational view on a reduced scale of the collapsible reel in its expanded condition;  
         [0019]      FIG. 4B  is a fragmentary, cross-sectional view through the expanded collapsible reel of  FIG. 4A  and taken on line  4 B- 4 B of  FIG. 7  through one of the three circumferentially spaced, foldable cable, conduit or tubing support units pivotally interconnecting the circular end flanges of the reel;  
         [0020]      FIG. 5A  is a generally schematic elevational view on a reduced scale of the collapsible reel in a partially collapsed condition;  
         [0021]      FIG. 5B  is a fragmentary, cross-sectional view taken on the same line as  FIG. 4B  and illustrating the support unit as depicted in  FIG. 4B  in its partially collapsed condition;  
         [0022]      FIG. 6A  is a generally schematic elevational view on a reduced scale of the reel in its fully collapsed condition with the circular flanges of the reel in side by side, substantially interengaging relationship;  
         [0023]      FIG. 6B  is a fragmentary, cross-sectional view through the reel in it filly collapsed condition;  
         [0024]      FIG. 7  is an end elevational view of one of the end flanges as molded with the cable, conduit or tubing support units molded in the positions thereof recessed in face;  
         [0025]      FIG. 8  is an isometric view of one of the three tubing support units that pivotally interconnect the end flanges of the reel;  
         [0026]      FIG. 9  is an expanded fragmentary cross-sectional view of one of the leg segments of a support unit and taken on the line  9 - 9  of  FIG. 7 ; and  
         [0027]      FIG. 10  is an enlarged fragmentary isometric view of a portion of one of the end flanges and showing one of the leg segments of a support unit telescoped in recesses for the leg segments in the flange. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0028]     The collapsible reel, broadly designated by the numeral  10  in the drawings, is especially adapted in its expanded condition, as shown in  FIG. 1  of the drawings to support cable, conduit or tubing  12  or the like wrapped around the central cage defining structure, designated by the numeral  14  in  FIG. 2 . Reel  10  includes two opposed, relatively thin, identical, generally circular, oppositely oriented, coaxially positioned end flange  16  and  18 .  
         [0029]     For simplicity, in view of the identical nature of flanges  16  and  18 , the same component parts of each of the flanges  16  and  18  are given the same number in the drawings. Thus, as is apparent from  FIGS. 1 and 2 , each of the circular end flanges  16  and  18  has an inner, relatively flat face  20  provided with a circular guide rod or pipe opening  22  in the center thereof.  
         [0030]     Three foldable cable, conduit or tubing support units  24  are hingedly connected to opposed inner faces  20  of end flanges  16  and  18 . Each support unit  24  includes a pair of identical leg segments  26  and  28  which are joined end-to-end by respective pivot pins  30  as best shown in  FIG. 8 , the leg segments  26  and  28  are of identical construction and are preferably molded in one-piece as detailed hereunder. Each leg segment  26  and  28  has a plurality of elongated, transversely spaced ribs  32  which are integral with a planar body portion  34 . It is to be noted from the cross-sectional view of  FIG. 9 . As is evident from that view, the two outer most rib portions  32   a  are of lesser height, the two innermost rib portions  32   b  are of greatest height and the rib portions  32   c  between respective outer most rib portions  32   a  and innermost rib portions  32   b  are of intermediate height. Ribs  32   a ,  32   b  and  32   c  are of heights selected so that in the extended condition of reel  10  with the leg segments  26  and  28  or each of the support units  24  are in linear, aligned relationship, as shown for example, in  FIGS. 3 and 4 A, the outer margins of ribs  32   a ,  32   b  and  32   c  collectively, essentially define an imaginary cylinder. For example, in the case of an illustrative reel  10 , having a diameter of 30″, the outer margins of ribs  32   a ,  32   b  and  32   c  of support units  24  may for example lie in imaginary cylinder having a radius of about 5″.  
         [0031]     The ends of leg segments  26  and  28  which are an end-to-end relationship as shown in  FIG. 8 , have interlocking cylindrical portions  36  provided with cross openings  38  therein for receipt of pivot pins  30 . It is to be further observed that the leg segments  26  and  28  of each support unit  24  are moveable from the straight-line disposition as shown in  FIGS. 4A-4B  to the filly folded positions shown in  FIGS. 6A and 6B  as the leg segments  26  and  28  pivot about pins  30 . Cooperable detents (not shown) may be provided on the ends of leg segments  26  and  28  which interengage in the extended linearally aligned disposition of leg segments  26  and  28  of support units  24  for retaining leg segments  26  and  28  filly extended until it is desired to fold support units  24  to collapsed reel  10 .  
         [0032]     The extremity of each of the ribs  32   b  of leg segments  26  and  28  remote from cylindrical portions  36  has a circular end surface  32   b ′ while the extremities of ribs  32   a  and  32   c  of each leg segment  26  and  28  have integral, semi-circular end caps  32   a ′ and  32   c ′. The end caps  32   a ′ and  32   c ′, and the ends of ribs  32   b  terminating in circular surfaces  32   b ′ of each of the leg segments  26  and  28  are provided with a series of aligned coaxial pivot pin receiving openings  40 . The cross-openings  40  through end caps  32   a ′ and  32   c ′, and the end surfaces  32   b ″ of leg segments  26  and  28  respectively have aligned, coaxial pivot pin receiving openings  40 . The aligned openings  40  at the outer ends of each of leg segments  26  and  28  receive elongated pivot pins  42 , each of which projects outwardly beyond the outer surfaces of end caps  32   a ′, as shown in  FIG. 2 .  
         [0033]     Inner faces  20  of end flanges  16  and  18  are defined by relatively thin, planar panel portion  44  ( FIGS. 9 and 10 ) which nominally may be approximately {fraction (1/4)}″ thick. In addition, all component portions of the flanges  16  and  18  are of the preferred ¼″ thickness. The ribs  32   a ,  32   b  and  32   c  are all approximately {fraction (1/4)}″ thick while planar bottom portion  34  of each of the leg segments  26  and  28  is preferably ⅛″ thick. The diameter of reel  10  as presented by flanges  16  and  18  may be varied, with one preferred dimension being about 30″. Each of the flanges  16  and  18  may, for example, be about 1½″ in depth front to back.  
         [0034]     The wall structure of end flanges  16  and  18  includes outwardly facing cell defining component portions which project in opposite directions from respective panel portions  44 , include an outer, annular cellular band  46  made up of a plurality of end-to-end generally rectangular open pockets  48  defined by the outer annular rim portion  50 , and inner rim portion  52  and a series of circumferentially spaced, radially extending wall portions  54 . The pockets  48  are approximately 1¼″ deep.  
         [0035]     A central outboard cellular section  56  of the flanges  16  and  18 , best shown in  FIGS. 2 and 3 , surrounds a respective opening  22  in coaxially relationship thereto and has a plurality of individual web segments  58  that make up a number of circumferentially extending open polygonal areas  60 . Here again, each of the areas  60  is approximately 1¼″ deep.  
         [0036]     An intermediate outboard cellular section  62  in each of the flanges  16  and  18  surrounds central cellular section  56  and has a series of generally radial, spaced webs  64  that cooperate with the inner rim portion  52  and web segments  58  to define a plurality of circumferentially extending open trapezoidal areas  66 . The areas  66  are also approximately 1¼″ deep.  
         [0037]     In those instances where three foldable support units  24  are provided between and pivotally connected to flanges  16  and  18 , three radially extending and circumferentially spaced cavity areas  68  are provided in the wall structure panel portion  44  of each of the flange  16  and  18 . The cavity areas  68  have a series of elongated, parallel, transversely spaced recesses for the respective ribs  32   a ,  32   b  and  32   c  of leg segments  26  and  28  of supports units  24  when the support units  24  are in their fully collapsed condition. As is most evident from  FIGS. 9 and 10 , each of the cavity areas  68  includes two elongated, outboard, unitary, transversely spaced, U-shaped recesses  68   a  configured to complementally receive respective outboard ribs  32   a  of a corresponding leg segment  26  and  28 . Similarly, two elongated, inboard, unitary, transversely spaced, U-shaped recesses  68   b  are provided which complementally receive respective ribs  32   b  of corresponding leg segments  26  and  28  of support units  24 . Two elongated, intermediate, unitary, transversely spaced, U-shaped recesses  68   c  complementally received the ribs  32   c  of leg segments  26  and  28  of support units  24 .  
         [0038]     When the support units  24  are unfolded to provide an extended reel as shown in  FIG. 3 , the reel  10  is adapted to receive a cable, conduit or tubing  12  as shown in  FIG. 1 . The imaginary cylinder defined by the outer margins of ribs  32  of the three support units  24  serves as a support for cable, conduit or tubing  12  which may be wound therearound in a pattern as shown in  FIG. 1 . The reel  10  with the cable, conduit or tubing  12  thereon may be shipped as a unit and a plurality of the reels stacked one on top of the other with the outer faces of the reels interengaging as is conventional with standard wooden reels. At the site of use, the reel  10  may be positioned on a support such as stand  70  as depicted in  FIG. 1 , in which a rod or pipe  72  passing through a line openings  22  in flanges  16  and  18  is typically received within a U-shaped open top saddle  72   a  forming a part of stand  70 . The cable, conduit or tubing  12  may be pulled from reel  10  as it rotates about the axis of rod or pipe  72 . Alternatively, reel  10  may be supported for rotation upon the body of a mobile vehicle such as a truck.  
         [0039]     Upon depletion of the supply of cable, conduit or tubing  12  carried by reel  10 , the reel  10  may be collapsed to the condition illustrated in  FIG. 6A  for shipment. The support units  24  may be folded about the axes of respective pivot pins  30  whereby ribs  32   a ,  32   b  and  32   c  are received in corresponding recesses  68   a ,  68   b  and  68   c . It can be observed from  FIG. 9  that the panel portion  44  of each of the flanges  16  and  18  has three radially extending, circumferentially spaced, rectangular indentations  74  in the faces  20  of panel portions  44  which are configured to complementally receive the planar bottom portion  34  of a respective leg segment  26  and  28  of support units  24 . As a consequence, when support units  24  are folded into their fully collapsed positions, the faces  20  of flanges  16  and  18  are in flat, fully conforming interengagement with essentially no space there between as shown schematically in  FIGS. 6A and 6B .  
         [0040]     It is also to be seen from  FIGS. 8 and 10  that when the leg segments  26  and  28  of the support units  24  are brought into linear, aligned relationship as best shown in  FIG. 8 , the extremities  32   a ″,  32   c ″ and  32   b ″ of leg segments  26  and  28  move into abutting relationship while adjacent ends of the flat surfaces of respective planar bottom portions  34  complementally interengage, thereby preventing the leg segments  26  and  28  from swinging overcenter during pivoting about pivot pins  30 . The interengagable detents on adjacent ends of fully opened leg segments  26  and  28  cooperate to maintain the leg segments  26  and  28  in end-to-end aligned relationship.  
         [0041]     A preferred procedure for manufacture of reel  10  involves pre-molding of a supply of leg segments  26  and  28 , which it is to be observed are of identical construction and configuration. The leg segments  26  and  28  maybe molded of a suitable synthetic resin such as polypropylene whereby the leg segments  26  and  28  are solid throughout the thickness of the individual leg segments  26  and  28 , or in the alternative, leg segments  26  and  28  may be fabricated of a synthetic resin composition in which a resin such as polyproplyene contains an amount of a blowing agent that is compatible with the resin. If formed, for example, from polypropylene which includes a quantity of a blowing agent, during molding of the parts, gases generated by the blowing agent cause the outer surface of the part to become denser than the interior portions of the part, thereby defining a tough, homogeneous, substantially void-free outer skin layer. The thickness of the skin layer will nominally be of the order of 0.060″ to about 0.100″. The overall thickness of the wall structures of flanges  16  and  18  will nominally be about ¼″.  
         [0042]     The outer rim portion  50  of each of the end flanges  16  and  18  which define the overall thickness of respective flanges  16  and  18  nominally or about 1½″. The leg segments  26  and  28  generally are about 1⅛″ thick overall. A fully collapsed reel  10 , as shown in  FIGS. 6A and 6B , has a maximum folded thickness of only about 3″.  
         [0043]     The faces of the three leg segments  26  or  28  of support units  24  which face outwardly to define cage  14  when reel  10  is unfolded, are sprayed with a mold release agent. The treated leg segments  26  or  28  with pins  42  in place in openings  40  are strategically placed in the mold for end flanges  16  or  18  with the outer surface of planar bottom portions  34  of leg segments  26  and  28  lying in a plane that is planar with the face  20  of the end flanges  16  or  18  to be molded.  
         [0044]     Next, a synthetic resin, such as polypropylene which contains a blowing agent, is introduced into the mold for a respective end flange  16  or  18 . The polypropylene/blowing agent composition is then allowed to expand into the cavity of the mold defining an end flange  16  or  18 . As previously explained, expansion of the polypropylene by the blowing agent incorporated into the resin formulation causes a relatively tough, homogeneous, substantially void-free outer skin layer to be formed throughout the extent of the end flange  16  or  18 , which fully encloses the cellular synthetic resin interior of the part. It is believed that the density of the resin making up the interior of the formed flange decreases in a direction away from the outer skin toward the center of the part.  
         [0045]     By forming each of the flanges  16  and  18  with the support units  24  in their normal folded positions thereof, support units  24  may readily be swung outwardly from the finished part because of the release agent that was applied to the surfaces of the leg segments  26  and  28  which face inwardly of the mold during the fabrication of a respective flange  16  or  18 . It is important to note in this respect that by molding of the leg segments  26  and  28  in place during forming of the end flanges  16  and  18 , the pivot pins  42  are also correctly molded in position. It would be difficult and more expensive to locate the pivot pins  42  in flanges  16  and  18  after molding of the flanges than is the case with molding of the pivot pins in place in flanges  16  or  18 .  
         [0046]     In addition, molding of the end flanges  16  and  18  with a leg segment  26  and  28  positioned in the flange mold results in the outer surfaces of ribs  32  accurately forming complemental recesses for ribs  32  of each leg segment  26  and  28  when the support units  24  are folded to collapse the reel  10  and thereby bring the faces  20  of end flanges  16  and  18  into proximal interengaging relationship.  
         [0047]     The synthetic resin used for molding of leg segments  26  and  28  of support units  24  should be of characteristics and properties such that the formed leg segment part is capable of withstanding and not be deformed by the elevated temperature environment within the interior of the mold(s) used to fabricate end flanges  16  and  18 .  
         [0048]     Although polypropylene is the preferred resin for fabrication of reel  10 , other resins may be employed such as high-density polyethylene. Suitable blowing agents for the resin include thermally decomposable foaming agents such as sodium bicarbonate, azodicarbonamide and the like, an inert gas such carbon dioxide, nitrogen and the like, or an organic compound having a low boiling point such as butane and the like. Additives may also be incorporated in the resin to enhance the physical characteristics of the formed reel, such as glass fibers or the like, particularly in the skin layer of the formed components, and inorganic fillers such as talc, silica, and the like added as a nucleating agent for the forming foam cells. A conventional flexiblizer component may be added to the resin if desired.  
         [0049]     Although the preferred reel  10  is constructed as illustrated and described having a cellular outer face in order to save weight and decrease the cost of the reel  10 , it is to be understood that if desired the wall structure of end flanges  16  and  18  may be essentially of solid construction except for the recesses receiving the ribs  32  of leg segments  26  and  28 . Similarly, support units  24  may be constructed as essentially flat components without the provision of ribs  32 . In these instances, the end flanges  16  and  18 , and support units  24  would desirably be molded of a synthetic resin having a blowing agent incorporated therein to produce end flanges and support units having a high strength to weight ratio.  
         [0050]     When formed of the defined resin and constructed of the dimensions described, a 30″ diameter reel having a fully opened width approximating that of the diameter of flanges  16  and  18  will hold at least about 400 pounds of cable, conduit or tubing wound therearound.