Abstract:
A cable hanger for securing multiple cables to support structures including antenna towers and poles. The cable hanger has a hingeably-coupled pair of shell halves with recesses that, when folded, establish a pair of cable passageways. Gripping arms provided on each of the shell halves project into a corresponding one of the cable passageways for gripping a cable positioned therein. Pairs of gripping arms located on opposite shell halves have a confronting relationship for gripping the cable on diametrically opposite side surfaces.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to devices for hanging cables and, in particular, to hangers for securing cables to structures including antenna poles and towers. 
     BACKGROUND OF THE INVENTION 
     Cable hangers are commonly used to secure cables to structural members of antenna poles and towers. Cables carry signals from ground-level equipment to sets of antennas attached at elevated positions on an antenna tower. Generally, each cable is attached to the antenna tower by a set of cable hangers mounted at periodically-spaced attachment points along its height. After the cable hangers have been attached to the antenna tower, the cable is strung upwardly and engaged with each of the cable hangers. 
     Generally, antenna poles and towers are crowded due to the multiplicity of cables required for signal-carrying. To conserve tower space, it is desirable for each set of cable hangers to have a capacity to route more than a single cable up the antenna tower. Certain cable hangers are constructed to secure multiple cables so each individual set of cable hangers can support a plurality of cables. Other cable hangers have a stackable construction that permits multiple cable hangers to be interlocked so as to extend outwardly from the antenna tower. Stacked and multiple-cable-type cable hangers significantly increase the number of cables that can be routed up the antenna tower by making efficient use of the available attachment points. 
     Conventional cable hangers configured to hold relatively small-diameter braided and corrugated cables suffer from significant deficiencies and shortcomings. In particular, conventional cable hangers are typically configured to handle cables of a single diameter. As a result, a unique cable hanger of suitable dimensions is required for each cable diameter. In addition, specifically-dimensioned cable hangers may be unable to accommodate variations in cable diameter arising from manufacturing tolerances and the like. This deficiency is particularly troublesome for conventional cable hangers configured to hold multiple cables. Moreover, the gripping ability of conventional cable hangers is limited because the gripped cable is merely engaged by the material forming the passageways of the cable hanger. 
     Therefore, it would be desirable to have a cable hanger configured for securing a plurality of cables each having a range of cable diameters and, in doing so, retaining the capability of gripping each cable with a relatively uniform gripping force about its circumference. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top perspective view of a cable hanger in accordance with the principles of the invention; 
         FIG. 2  is a bottom perspective view similar to  FIG. 1 ; 
         FIG. 3  is a perspective view of the cable hanger of  FIG. 1  in which the shell halves are folded to a closed condition; 
         FIG. 4  is an end view of the cable hanger of  FIG. 3 ; 
         FIG. 4A  is a sectional view taken generally along lines  4 A— 4 A of  FIG. 4 ; 
         FIG. 4B  is a sectional view taken generally along lines  4 B— 4 B of  FIG. 4 ; 
         FIG. 4C  is a view similar to  FIG. 4B  in which the shell halves of the cable hanger have been compressed together; and 
         FIG. 5  is a perspective view showing an alternative embodiment of a cable hanger in accordance with the invention, comprising three pairs of shell halves of different dimensions joined together in a stacked assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention is directed to cable hangers configured for securing a plurality of, for example, two cables within a range of cable diameters and, in doing so, grip each cable with a relatively uniform gripping force about its circumference. Although the invention will be described next in connection with certain embodiments, it will be understood that the invention is not limited to those particular embodiments. On the contrary, the description of the invention is intended to cover all alternatives, modifications, and equivalent arrangements as may be included within the spirit and scope of the invention as defined by the appended claims. 
     With reference to  FIGS. 1 and 2 , a cable hanger  10  of the invention includes a front shell half  12  and a rear shell half  14  hingeably joined together by a spaced-apart pair of living hinge couplings  16 ,  18 . The shell halves  12 ,  14  are folded or closed one onto the other so as to create an enclosing or encasing structure. When folded, respective inner surfaces  20 ,  22  of the shell halves  12 ,  14  have a confronting relationship and respective outer surfaces  24 ,  26  of the shell halves  12 ,  14  face away from each other in opposite directions. The living hinge couplings  16 ,  18  are provided for temporarily coupling the shell halves  12 ,  14  together until folding for assembly and may be frangible. The relative thinness of the living hinge couplings  16 ,  18  relative to the shell halves  12 ,  14  facilitates the folding of the shell halves  12 ,  14 . 
     Cable hanger  10  is self-locking so that the shell halves  12 ,  14  are retained in the folded condition. To that end, a reversible snap-fit is provided by the engagement between tongue or flange  28  and a slotted opening  30  in the front shell half  12 , and the engagement between a tongue or flange  32  and a side edge  34  of the rear shell half  14 . Flange  28  projects outwardly from the rear shell half  14  at a position adjacent to, and generally between, the hinge couplings  16 ,  18 . Flange  32  projects outwardly from the front shell half  12  at a position opposite to the hinge couplings  16 ,  18 . 
     With continued reference to  FIGS. 1 and 2 , flange  28  has a beveled head, generally indicated by reference numeral  36 , that engages, and is captured by, an inner peripheral edge  38  of the slotted opening  30  in the front shell half  12 . Similarly, flange  32  has a beveled head that engages, and is captured by, the side edge  34  of the rear shell half  14 . A pair of guides  41 ,  42  project outwardly from the side edge  34  of the rear shell half  14  and have a flanking relationship with the portion of the side edge  34  engaged by a beveled head  40  of flange  32 . When the shell halves  12 ,  14  are joined by folding at the hinge couplings  16 ,  18 , an upwardly-facing angled camming surface  44  of flange  28  rides over the inner peripheral edge  38  of slotted opening  30 , which causes flange  28  to deflect laterally. The flange  28  returns to an undeflected condition when the camming surface  44  loses contact with the inner peripheral edge  38  to provide a snap-fit, locking engagement between a lip  46  of the flange  28  and the peripheral edge  38  of slotted opening  30 . Similarly, an upwardly-facing angled camming surface  48  ( FIG. 4A ) of flange  32  rides over the side edge  34  when the shell halves  12 ,  14  are joined by folding at the hinge couplings  16 ,  18 , which causes the flange  32  to deflect laterally. The flange  32  relaxes back to an undeflected condition when the camming surface  48  and side edge  34  are non-contacting to provide a snap-fit action that results in a locking engagement between a lip  50  ( FIG. 4A ) of flange  32  and the side edge  34 . 
     With reference to  FIGS. 1 ,  2  and  3 , the inner surface  20  of shell half  12  includes at least one and, typically, a plurality of, for example, two semi-circular, cylindrical recesses  52 ,  53  divided by a spacer portion  54  and, similarly, the inner surface  22  of shell half  14  includes at least one and, typically, a plurality of, for example, two semi-circular, cylindrical recesses  56 ,  57  divided by a spacer portion  58 . When the shell halves  12 ,  14  are folded and snap-closed, recess  52  is registered with recess  56  to define a cylindrical, cable-gripping passageway  59  ( FIG. 3 ) with a geometric centerline  59   a  and recess  53  is registered with recess  57  to define another cylindrical, cable-gripping passageway  60  ( FIG. 3 ) having a geometric centerline  60   a.  It is appreciated that the number of cable-gripping passageways is related to the number of recesses incorporated into each cable half  12 ,  14 . The cross-sectional profile of the passageways  59 ,  60  is generally circular for receiving cables  101  ( FIG. 4 ) that are circular, oval, or elliptical. Positioned at the opposite entrances to the recesses  52 ,  53 ,  56 , and  57  are corresponding radiused surfaces  52   a,b,    53   a,b,    56   a,b,  and  57   a,b.    
     An annular mounting post  62  extends outwardly from the outside surface  24  of the spacer portion  54  and defines a mounting channel or fastener opening  64  having a geometric centerline extending generally perpendicular to the geometric centerline  59   a  of cable passageway  59 . Similarly, provided between the recesses  56 ,  57  of shell half  14  is an annular mounting post  66  that extends outwardly from outer surface  26  of spacer portion  58  and defines a fastener opening or mounting channel  68  having a geometric centerline extending generally perpendicular to the geometric centerline of cable passageway  60 . When the shell halves  12 ,  14  are folded, the mounting channels  64 ,  68  are registered to define a fastening passageway configured and dimensioned to receive, for example, a threaded rod  69  ( FIG. 5 ) for use in securing the cable hanger  10  to a structural member  70  (FIG.  5 ). 
     With continued reference to  FIGS. 1 ,  2  and  3 , provided on mounting post  62  is a pair of circumferentially-spaced keys  72  separated by corresponding keyways  73 . Similarly, a pair of circumferentially-spaced keys  74  provided on a mounting post  66  are separated by keyways  75 . Each of the keys  72 ,  74  extends about an angular arc of about 90°. The keys  72 ,  74  and keyways  73 ,  75  permit cable hanger  10  to be stacked with other cable hangers  10 . To that end, the keys  72  and keyways  73  of one cable hanger  10  are interlockable with the keys  74  and keyways  75  of a second cable hanger  10  to provide an assembly in which the two cable hangers  10  have a controlled angular relationship and are not relatively rotatable. In the folded condition, the keys  72  are angularly offset from keys  74  by about 90° so that the cable passageways  59 ,  60  of one cable hanger  10  are aligned generally parallel with the cable passageways  59 ,  60  of the other stacked cable hanger  10  when the keys  72 ,  74  and keyways  73 ,  75  are interlocked. A plurality of cable hangers  10  may be stacked in this manner with interlocked keys  72 ,  74  and keyways  73 ,  75 . It is contemplated by the invention that keys  72 ,  74  and keyways  73 ,  75  may have any suitable complementary construction for interlocking multiple, stacked cable hangers  10  for aligning the cable passageways  59 ,  60  of one cable hanger  10  with the cable passageways  59 ,  60  of another cable hanger  10  and may be located at other alternative locations on the respective shell halves  12 ,  14 . For example, one cable hanger  10  may be provided with a single key  72  on post  62  and another cable hanger  10  may be provided with a single keyway  75  on post  66  positioned and configured for engaging key  72 . 
     Provided with a spaced relationship within recess  52  is a plurality of, for example, two cantilevered gripping arms or fingers  76   a,    78   a  and, similarly, provided with a spaced relationship within recess  53  is a plurality of, for example, two cantilevered gripping arms or fingers  77   a,    79   a,  each of which is flexibly attached to spacer portion  54 . Similarly, recess  56  includes a spaced-apart pair of cantilevered gripping arms or fingers  77   b,    79   b  and recess  57  includes a spaced-apart pair of cantilevered gripping arms or fingers  76   b,    78   b,  each of which is flexibly attached to spacer portion  58 . Each of the gripping fingers  76   a,b,    77   a,b,    78   a,b,  and  79   a,b  is received in a corresponding one of a plurality of slotted openings  80  provided in the shell half  12  or a plurality of slotted openings  82  provided in shell half  14 , which provide respective unoccupied spaces for receiving the outwardly-deflected gripping fingers  76   a,b,    77   a,b,    78   a,b,  and  79   a,b.  Gripping fingers  76   a,b,    77   a,b,    78   a,b,  and  79   a,b  are aligned substantially perpendicular to an axis extending along the geometric centerline of the corresponding one of cable passageways  59 ,  60 . 
     With reference to  FIGS. 4 ,  4 A and  4 B, gripping finger  76   a  extends away from a fixed end  84  attached to spacer portion  54  toward a free end  86 . Because of their structural identity, the following discussion of gripping finger  76   a  is equally applicable to the other gripping fingers  76   b,    77   a,b,    78   a,b,  and  79   a,b.  Gripping finger  76   a  includes a first segment  88  adjacent the fixed end  84  having a concave-inward surface of substantially the same radius of curvature as recess  52 . Gripping finger  76   a  further includes a second segment  90  having an inwardly-facing planar surface  91  and a third segment  92  having an inwardly-facing planar surface  93  inclined at an acute angle relative to planar surface  91 . The planar surfaces  91 ,  93  project into the recess  52  so as to have a contacting relationship with a cable of a sufficient diameter positioned between recess  52  and the complementary recess  57  of shell half  14  when the shell halves  12 ,  14  are folded. The contact resiliently deflects gripping finger  76   a  from a relaxed state outwardly to apply a gripping force to the cable  101 . 
     Extending along the planar surface  91  and the planar surface  93  is a raised rib  94  having a triangular cross-sectional profile that tapers outwardly from the surfaces  91  and  93  toward its tip. The rib  94  contacts the cable  101  to provide additional resistance against movement of the cable hanger  10  relative to the cable  101 . A reinforcing rib  96  extends along the backside of the gripping finger  76   a.    
     With continued reference to  FIGS. 4 ,  4 A and  4 B, the planar surfaces  91 ,  93  of gripping finger  76   a  are generally confronting with the corresponding planar surfaces  91 ,  93  of gripping finger  76   b  when the shell halves  12 ,  14  are folded together. The cable  101  received in passageway  59  is contacted on generally opposite sides by gripping fingers  76   a  and  76   b  as the gripping fingers  76   a,b  are separated by a distance smaller than a dimension of cable  101 . Similarly, the planar surfaces  91 ,  93  of gripping finger  78   a  are generally confronting with the corresponding planar surfaces  91 ,  93  of gripping finger  78   b  when the shell halves  12 ,  14  are folded together. The cable  101  received in passageway  59  is contacted on generally opposite sides by gripping fingers  76   a  and  76   b  and by gripping fingers  78   a  and  78   b.  A similar confronting relationship exists between the planar surfaces  91 ,  93  of gripping fingers  77   a  and  77   b  and the planar surfaces  91 ,  93  gripping fingers  79   a  and  79   b.    
     Projecting outwardly from each of the recesses  52 ,  53 ,  56 ,  57  is a plurality of, for example, three raised gripping ribs  98  that frictionally engage the cable  101  to inhibit or otherwise prevent the cable hanger  10  from sliding along the length of the cable  101 . The gripping ribs  98  are effective for supplementing the gripping ability of the gripping fingers  76   a,b,    77   a,b,    78   a,b,  and  79   a,b  for larger diameter cables  101  that deflect the gripping fingers  76   a,b,    77   a,b,    78   a,b,  and  79   a,b  sufficiently outwardly to allow contact between the cable  101  and the gripping ribs  98 . Each of the gripping ribs  98  has a generally triangular cross-sectional profile capable of penetrating into the cable  101  for further improving the gripping ability for large-diameter cables  101 . 
     With references to  FIGS. 4 ,  4 B and  4 C, the inner surfaces  20 ,  22  of the folded shell halves  12 ,  14  are separated at the spacer portions  54 ,  58  by a gap  100 . Gap  100  has a width of D 1 , as show in  FIG. 4B , when the shell halves  12 ,  14  are folded and flanges  28  and  32  are interlocked with slotted opening  30  and side edge  34 , respectively. The separation between the gripping fingers  76   a,b  and gripping fingers  78   a,b  is smaller than the diameter or other dimension of cable  101  so that deflection occurs at least when the shell halves  12 ,  14  are compressed together. Assuming that cable  101  is present in passageway  59 , gripping fingers  76   a,b  and gripping fingers  78   a,b  are deflected outwardly into a corresponding one of the slotted recesses  80 ,  82  by contact with the outer surface of cable  101  when the shell halves  12 ,  14  are snap-fitted together. 
     Gap  100  narrows to a width of D 2  when the shell halves  12 ,  14  are forced or compressed together by tightening of a fastening element, such as nut  104 , on the threaded rod  69  ( FIG. 5 ) so as to decrease the spacing between inner surfaces  20 ,  22 . The threaded rod  69  and nut  104  collectively provide a fastening member for attaching the cable hanger  10  to the structural member  70 . As gap  100  narrows due to the compression, recess  52  approaches recess  57  and recess  53  approaches recess  56  so as to reduce the effective diameter of the associated cable passageway  59  to further assist in gripping the cable  101  by allowing for additional deflection of the gripping fingers  76   a,b  and  78   a,b.  The narrowing of the gap  100  from D 1  to D 2  may permit the cable  101  to contact the raised ribs  98  on the inwardly-facing surfaces of recesses  52 ,  57 , which also provides the largest outward deflection of the corresponding pairs of gripping fingers  76   a,b  and  78   a,b,  so as to optimize the gripping or clamping force applied to cable  101 . It is appreciated by persons of ordinary skill that another cable  101  is positioned within cable passageway  60  in the same manner as described above for cable  101  in cable passageway  59 . 
     The cable hanger  10  is molded as a unitary structure from a suitable polymer resin, such as conventional thermoset or thermoplastic resins. An exemplary polymer resin is the thermoplastic resin polyoxymethylene (POM) or acetal copolymer which is commercially availabe, for example, under the CELCON® tradename from Ticona (Summit, N.J.). 
     In use, a cable  101  is captured within at least one of the cable passageways  59 ,  60  by folding shell halves  12 ,  14  relative one another relative to the living hinge couplings  16 ,  18 . Gripping fingers  76   a  and  76   b  and gripping fingers  78   a  and  78   b  engage any cable  101  present in passageway  59  and, similarly, gripping fingers  77   a  and  77   b  and gripping fingers  79   a  and  79   b  engage any cable  101  present in passageway  60 . Gripping fingers  76   a,    76   b,    78   a,    78   b  and gripping fingers  77   a,    77   b,    79   a,    79   b  are deflected outwardly into a corresponding one of the slotted openings  80 ,  82 . The threaded rod  69  is inserted into the registered fastener openings  64 ,  68  and nut  104  is advanced to compress the shell halves  12 ,  14  together for narrowing gap  100  from its initial width of D 1  to a smaller width of D 2 . The narrowing of gap  100  increases the clamping force applied by gripping fingers  76   a,    76   b,    78   a,    78   b  and gripping fingers  77   a,    77   b,    79   a,    79   b  to cables  101  present in cable passageways  59 ,  60 , respectively. 
     With reference to  FIG. 5  in which like reference numerals refer to like features in  FIGS. 1-4 , the cable hanger  10  of the invention may be dimensionally scaled for receiving cables  101  having a range of exterior dimensions and dimensions for cable passageways  59 ,  60  (FIG.  3 ), as illustrated by cable hangers  10 ,  10 ′ and  10 ″. Although the dimensions of the cable hangers  10 ,  10 ′, and  10 ″ differ, the diameter of the fastener openings  64 ,  68 , the inner and outer diameters of the annular mounting posts  62 ,  66 , and the location and angular-spacing between keys  72  and keys  74  are maintained unchanged so that cable hangers  10 ,  10 ′, and  10 ″ of different dimensions may be stacked by engaging keys  72  with keys  74 . The cable hangers  10  are stacked by inserting threaded rod  69  through the aligned fastener openings  64 ,  68  in the folded and interlocked shell halves  12 ,  14  for each of three cable hangers  10 ,  10 ′, and  10 ″. The cable hangers  10 ,  10 ′, and  10 ″ are secured to the support structure  70  either vertically, horizontally or at angle to an axis of the support structure  70  using, for example, a bracket  102 . Among the support structures  70  to which the cable hanger  10  may be attached are angle, round, flat, and channel members. A fastener element  104  is threadingly engaged with the threaded rod  69  and advanced to compress the shell halves  12 ,  14  of the cable hangers  10 ,  10 ′, and  10 ″ together for closing the respective gaps  100  and for clamping the respective cables  101  to prevent movement of each of the cable hangers  10 ,  10 ′, and  10 ″ along the length of the respective cables  101 . The invention contemplates that a plurality of two or more cable hangers  10  may be stacked according to the principles of the invention and that the present invention includes, but is not limited to, the embodiment of FIG.  5 . It is contemplated by the invention that the exterior dimensions of the cable hangers  10 ,  10 ′ and  10 ″ may be substantially identical and that the dimensions of the cable passageways  59 ,  60  may be varied for securing cables  101  of various ranges of diameters. 
     While the present invention has been illustrated by a description of various preferred embodiments and while these embodiments have been described in considerable detail in order to describe the best mode of practicing the invention, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the spirit and scope of the invention will readily appear to those skilled in the art. The invention itself should only be defined by the appended claims, wherein we claim: