Modular cable support apparatus, method, and system

[0001] The present invention relates to the cable support arts. It particularly relates to supporting and suspending cables from poles or other overhead support structures, and will be described with particular reference thereto. The invention will also find application in conjunction with various types of cables such as telephone cables, cables for “cable” television, high tension wires, fiber optical cables, and optical ground wires (OPGW's). In addition to suspending cables from poles and the like, the present invention is operative with flat support surfaces and, accordingly finds use in supporting cables and other objects in vault and other similar or related applications.

[0002] Power lines, telephone transmission lines, and other cables are frequently suspended aerially from a plurality of poles or other support structures. An aerial cable arrangement is relatively simple and flexible, and has a limited ground footprint that frequently permits space substantially below the suspended cables to be used for other purposes. An aerial arrangement also vertically separates the cables from people or roaming ground animals and reduces the possibility of detrimental contact therewith. Spatial separation is particularly useful for electrical power transmission cables for safety reasons. Aerial suspension of a cable also helps reduce damage caused either inadvertently or through malicious vandalism.

[0003] Although aerial cables are relatively safe from ground-based sources of damage, they are subject to environmental wear and damage, principally due to winds. Well known in the art are problems caused by aeolian vibration which is a high frequency, low amplitude vibration caused by laminar winds passing across the line, as well as “galloping” which is a low frequency, high amplitude wind-induced cable motion. Wind action can produce cable damage in the form of abrasion, wear, and fatigue, especially at the suspension points where cable support devices inherently form mechanical stress points in the cable. The potential for such damage can be increased by excessive clamping force, by inadequate clamping force which allows the cable to slide within the clamp, or by an uneven or non-uniform clamping force.

[0004] Another issue with pole-mounted cables is efficient arrangement of the various cables. This issue is increasingly confronted due to the rapid proliferation of cable-based transport of electrical power and communication signals. Utility poles typically support cables carrying electrical power, telephone signals, and cable television signals. High-capacity fiber optic cables are being installed in many localities, either for replacing existing electrical signal communication lines or to add additional capacity such as high-speed dedicated Internet access.

[0005] Cables sag between the supporting poles, and under the influence of wind the cables can sway about and impinge on one another. Such impingement can damage the cables and also potentially creates safety issues, as for example if a power cable electrically contacts a nearby telephone cable. It is known in the art that a staggered arrangement of the cables, i.e. placing the cables at different heights, reduces the likelihood of damaging impingements.

[0006] Yet another area of concern with cable support devices is interchangeability. Cable support installation and maintenance is performed in the field. Cable support devices are typically warehoused at one or more central facilities, for example owned by the utility, and maintenance crews select and bring those selected supports deemed necessary for the various repair jobs to be performed on a given day. Selecting the wrong type of support can delay the installation or maintenance and can create or prolong power or communication outages. The problem becomes more acute during emergency situations such as when there is an immediate need during and after severe thunderstorms, when many critical cables may be damaged at essentially the same time. These problems could be mitigated by a modular cable support system comprising a plurality of adaptable multi-purpose components from which a plurality of different types of cable support devices are constructable.

[0007] The present invention contemplates an improved cable support apparatus, method, and system which overcomes the aforementioned problems and others.

[0008] According to one aspect of the invention, a cable support is disclosed. A clamp base includes a projecting structure on a first side and a receiving structure on an opposite side. The receiving structure is adapted to receive the projecting structure of an identical clamp base. The clamp base further includes a base hinge edge. A clamp keeper has a keeper hinge edge adapted to hingeably attach with the base hinge edge. The clamp keeper and the clamp base together define a cable cavity for receiving an associated cable. The clamp keeper further cooperates with the clamp base to effectuate clamping of the associated cable therebetween.

[0009] According to another aspect of the invention, a method is provided for attaching a plurality of cables to a pole. A first support base is connected to the pole. A first cable is supported by the first support base. A second support base is connected to the first support base. A second cable is supported by the second support base.

[0010] According to another aspect of the invention, a modular cable support system is provided including a plurality of bases. Each base has an interconnecting structure including a projection and a slot wherein the projection is adapted to insert into the slot of another base for connection therebetween. Each base also has a base hinge edge and a cable channel. A plurality of clamping elements is provided. Each clamping element includes a hinge edge adapted to hingeably attach with the base hinge edge of a selected base, and a clamping surface adapted to cooperate with the cable channel of the selected base for retaining an associated cable.

[0011] According to yet another aspect of the invention, a cable clamp is provided including a first clamp portion and a second clamp portion. The first clamp portion has a first hinge region including a first curved projection and a first receiving opening. The first clamp portion also has a first tightening region, and a first cable channel region arranged between the first hinge region and the first tightening region. The second clamp portion has a second hinge region including a second curved projection and a second receiving opening. The second clamp portion also has a second tightening region, and a second cable channel region arranged between the second hinge region and the second tightening region. The first and second hinge regions cooperatively form a hinge. The hinge includes the first curved projection arranged in the second opening and the second curved projection arranged in the first opening. The hinges are formed having a slight material interference to compensate for tolerance or dimensional changes due to the manufacturing process.

[0012] According to still yet another aspect of the invention, a cable support system is provided including a plurality of first components. Each first component has an interconnecting structure, a cable channel, and a hinge edge and tightening region disposed on opposite sides of the cable channel. A plurality of second components is also provided. Each second component has a hinge edge, a tightening region disposed on an opposite side from the hinge edge, and a cable channel arranged between the hinge edge and the tightening region. A first cable support device is constructable by hingeably combining selected first and second components via the hinge edges. A second cable support device is constructable by hingeably combining selected two second components via the hinge edges.

[0013] One advantage of the present invention resides in its ability to arrange a plurality of cable supports in a staggered-height fashion to allow greater clearance between adjoining cables thereby reducing the likelihood of cable impingement.

[0014] Another advantage of the present invention resides in an adaptable hinge which improves clamping force uniformity in the presence of variations in the clamp tightening and/or in the presence of winds or other cable stresses.

[0015] Yet another advantage of the present invention resides in its modular nature wherein the various cable support components are modularly combinable to form a plurality of different types of cable support devices.

[0016] Numerous additional advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments.

[0029] With reference to FIGS. 1 and 2, a cable support 10 in accordance with a first preferred embodiment of the invention includes a lower clamp base 12 and upper clamp keeper 14. The clamp base 12 includes a hinge region 16, a tightening region 18, and a cable channel region 20 arranged between the hinge and tightening regions 16, 18. The clamp base 12 also includes an interconnecting structure 22 for adapting the base for connection to a pole or other structure and for adapting a plurality of bases 12 to be interconnected as will be described in greater detail below. The clamp keeper 14 includes a hinge region 24, a tightening region 26, and a cable channel region 28 arranged between the hinge and tightening regions 24, 26.

[0030] With continuing reference to FIGS. 1 and 2 and with further reference to FIG. 3, the clamp base 12 and the clamp keeper 14 are adapted to selectively cooperatively hingedly connect via the hinge regions 16, 24. The clamp base hinge region 16 includes a curved tab or projection 30 that mates with an opening or slot 32 of the clamp keeper hinge region 24, and similarly the clamp keeper hinge region 24 includes a curved tab or projection 34 that mates with an opening or slot 36 of the clamp base hinge region 16, to form a hinge 40 shown in FIG. 3. With reference to FIG. 3 the clamp base 12 and the clamp keeper 14 hingedly connect to form a hinged clamp body of the cable support 10. In the preferred embodiment, two cable insert grommets 42 are arranged in the cable channel regions 20, 28 of the cable support 10 to provide a cable cushioning interface.

[0031] With continuing reference to FIGS. 1-3 and with further reference to FIG. 4, in typical use, the cable support 10 supports a cable 50 from a utility pole 52. The cable 50 is clamped by a tightening shaft 54, at least a portion of which is threaded (not shown). In the preferred embodiment, the shaft 54 is a bolt that passes through an opening 56 arranged in the tightening region 26 of the clamp keeper 14 and threads into a threaded opening 58 of the tightening region 18 of the base 12. Alternatively, the opening 58 is not threaded and a nut (not shown) or other means are provided to connect with the bolt 54 to effectuate threaded tightening. Other tightening means can also be used. In the illustrated embodiments, washers 60 are included to facilitate the tightening.

[0032] The clamp base 12 and the clamp keeper 14, when hingeably interconnected and tightened by tightening means 54 onto the cable 50, define second-class levers that cooperatively act on the cable 50. The fulcrum of the levers is the hinge 40, and the tightening means 54 supplies the applied force which draws the tightening portions 18, 26 together about the hinge 40 to act on the load cable 50 that is interposed between the fulcrum and the applied force.

[0033] Those skilled in the art will appreciate that the hinge 40 overcomes significant problems encountered in previous cable supports with regard to hinged clamping action. The curved tabs 30, 34 include concave surfaces that adaptively contact surfaces of the respective slots 32, 36 to maintain even and uniform clamping of the cable 50 over a wide range of drawing forces and cable stresses. Preferably, the cooperative curved tabs 30, 34 and coupling slots 32, 36 are adaptive to maintain uniform clamping over at least selected design tolerance ranges of drawing forces and cable stresses. The hinge 40 is also readily disassembled, thus facilitating modular use of the components 12, 14.

[0034] In the application illustrated in FIG. 4, the cable support 10 is itself rigidly connected to the pole 52 using a suitable lag bolt 62 that passes through the pole 52 and an opening 64 (best seen in FIG. 1) in the interconnecting structure 22 of the cable support base 12. The lag bolt 62 is threadedly secured at each end by nuts 66. In the illustrated embodiment, anti-rotation ribs 68 (best seen in FIG. 3) are arranged on the interconnecting structure 22 of the cable support base 12. The ribs 68 define a mounting bracket adapted to contact the pole 52 and bias the base 12 against rotating relative to the pole 52.

[0035] With particular reference to FIG. 5, another method for connecting the cable support 10 to the pole 52 is shown. A banding strap 70 wraps around the pole 52 and also passes through a slot 72 (best seen in FIG. 2) in the interconnecting structure 22 of the base 12 to rigidly fasten the cable support 10 against the pole 52. Again, the anti-rotation ribs 68 define a mounting bracket that prevents rotation of the base 12 relative to the pole 52.

[0036] FIG. 5 shows the cable support 10 with the tightening shaft 54 disengaged from the threaded opening 58 and the hinge 40 partially opened. It is to be appreciated, however, that the clamp keeper 14 is nonetheless prevented from disengaging completely at the hinge 40 because the utility pole 52 prevents the hinge from opening wide enough for disengagement of the tabs 30, 34 from coupling slots 32, 36. This arrangement is advantageous because it allows maintenance workers to open the cable support 10 to replace the cable 50 without risk that the cable support 10 will be inadvertently disassembled. Such inadvertent disassembly could result in the clamp keeper 14 falling down, creating inconvenience and a potential safety hazard. It will be additionally appreciated that a similar interaction between the support 10 and the pole 52 also secures the clamp keeper 14 in the arrangement of FIG. 4 which employs the lag bolt 62.

[0037] With continuing reference to FIGS. 1-5 and with further reference to FIGS. 6-8, modular interconnecting of a plurality of cable support bases 12 by the interconnecting structures 22 is described. Each interconnecting structure 22 includes a projection or key tang 80 at one end and a receiving recess or slot 82 at an opposite end (best seen in FIGS. 2, 3, and 6) which is defined at least in part by the anti-rotation ribs 68. As best seen in FIG. 6, the tang 80₁ of a first support base 12₁ is adapted to insert into the slot 82₂ of a second support base 12₂ between the ribs 68₂. With particular reference to FIGS. 6 and 7, two bases 12₁, 12₂ are secured together by a fastening shaft or bolt 84 which passes through openings 64₁, 64₂ in the interconnecting structures 22₁, 22₂ of the bases 12₁, 12₂ and is secured by a nut 86 and optional facilitating washers 88. The interconnected bases are fastened to the pole 52 by the banding strap 70 using the slot 82₁ and the ribs 68₁ which were not used in the interconnecting and are available for attaching the interconnected arrangement of the bases 12₁, 12₂ to the pole 52 or other fixed structure. This attachment is similar to the banding strap attachment of a single base 12 previously described with reference to FIG. 5.

[0038] With continuing reference to FIG. 7, interconnected cable supports 10₁, 10₂ further include clamp keepers 14₁, 14₂ which are hingeably attached to the interconnected bases 12₁, 12₂, respectively in a manner described above. Cables 50₁, 50₂ are inserted, and the cable supports 10₁, 10₂ are tightened by tightening means 54₁, 54₂, respectively.

[0039] An advantageous result deriving from the modular interconnected cable supports 10₁, 10₂ is that the position of the cables 50₁, 50₂ is staggered above and below the level of the fastening shaft 84. Such a staggered arrangement beneficially promotes cable separation and reduces the likelihood of cable impingement during windy conditions.

[0040] With reference next to FIG. 8, a modular arrangement of three (3) cable supports 10₁, 10₂, 10₃ for supporting three (3) cables 50₁, 50₂, 50₃ is described. Bases 12₁, 12₂, 12₃ are interconnected via tang-and-slot arrangements as described previously. However, the fastening shaft 84 of FIG. 7 is replaced by the lag bolt 62 which also secures the interconnected bases 12₁, 12₂, 12₃ to the pole 52 in cooperation with the nuts 66 and anti-rotation ribs 68₁ (not seen in FIG. 8). The securing of the three bases 12₁, 12₂, 12₃ by the lag bolt 62 is similar to the securing of a single base described previously with reference to FIG. 4. In FIG. 8, however, the lag bolt 62 serves the dual purposes of securing the interconnection of the three bases 12₁, 12₂, 12₃ and the securing of these bases to the pole 52. The cable supports 10₁, 10₂, 10₃ also include clamp keepers 14₁, 14₂, 14₃ that are hingeably attached to the corresponding interconnected bases 12₁, 12₂, 12₃, and appropriate tightening hardware 54₁, 54₂ , 54₃ for securing cables 50₁, 50₂, 50₃ in the supports 10₁, 10₂, 10₃, respectively.

[0041] With continuing further reference to FIG. 8, it is to be appreciated that the unused tang 80₃ can optionally be used to secure a fourth base (not shown), and that furthermore an arbitrary number of bases can be stacked in like fashion, limited only by the structural stability of the interconnected bases. In one suitable embodiment for supporting fiber optic cables, the bases 12 and the clamp keepers 14 are made from light-weight sturdy materials suitable for supporting a plurality of cables using arrangements similar to those illustrated in FIGS. 7 and 8. The preferred materials include cast aluminum and aluminum alloys.

[0042] FIG. 8 also clearly shows the staggered arrangement of the cables 50₁, 50₂, 50₃ supported by the subject modular clamp. As can be seen, the cables are alternatively positioned above, below, and above the lag bolt 62, respectively. It is also apparent that the first cable support 10₁ could instead be connected to the pole 52 in an upside-down orientation relative to that shown in FIG. 8, so that cable 50₁ would be arranged below the lag bolt 62, in which case the cables 50₂, 50₃ would alternate above and below the lag bolt 62, respectively.

[0043] With reference once again overall to FIGS. 1-8, a modular cable support 10 has been described, which provides for mounting one or a plurality of cables from a pole or other fixed structure using a lag bolt 62 or a banding strap 70. Of course, the interconnecting structure 22 is readily adaptable to accommodate other mechanisms for fastening the base 12 to the pole 52 or other structure. The tang-and-slot arrangement of the interconnecting structure 22 also permits modular interconnection of two or more bases horizontally in a staggered manner. This is particularly advantageous since in many localities the various users of cable support poles, such as telephone, electrical power, and cable television companies, are allocated selected height ranges for their cables. The horizontal interconnection thus allows several cables to be connected at essentially the same height offset only slightly by the staggering distance.

[0044] With reference next to FIGS. 9-11, another aspect of the subject modular cable support system is described, wherein a suspension clamp 100 is provided by combining two cable keepers 14_a, 14_b. The suspension clamp 100 is suitable for suspending a cable from an associated overhead structure, such from as an overhead support wire, an overhead high-tension power line tower, or the like. As seen in exploded view of FIG. 9, in addition to utilizing the clamp keepers 14_a, 14_b, the suspension clamp 100 further utilizes two (2) of the cable insert grommets 42, the tightening bolt 54, and a self-locking nut 104, which components are also used in the cable support 10 of FIGS. 1-8. Thus, these components are modular and are selectively assembled as desired to make a cable support 10 of the type shown in FIGS. 1-8, or can be assembled to make the suspension clamp 100 of FIGS. 9-11.

[0045] With continuing reference to FIGS. 9-11, the curved projection 34_a of the clamp keeper 14_a selectively mates with the opening or slot 32_b of the clamp keeper 14_b and similarly the curved projection 34_b of the clamp keeper 14_b selectively mates with the opening or slot 32_a of the clamp keeper 14_a to thereby cooperatively form a hinge 102. The hinge 102 connects the clamp keepers 14_a, 14_b and has the same advantageous adaptive properties as the hinge 40 of the cable support 10. The curved tabs 34_a, 34_b include concave surfaces that adaptively contact surfaces of the respective slots 32_b, 32_a to maintain an even and uniform clamping force over a wide range of drawing forces and cable stresses.

[0046] In the illustrated cable support device 10 of FIGS. 1-8, the bolt 54 threads into the threaded opening 58 of the tightening region 18 of the cable support base 12 to effectuate threaded tightening. In such an arrangement, the opening 56 in the tightening region 26 of the clamp keeper 14 is advantageously an unthreaded hole passing through the tightening region 26 which is large enough to allow the bolt 54 to rotate freely therein. Hence, in constructing the suspension clamp 100, a “pin-loc” type hexnut 104 threads onto the bolt 54 to provide the threaded tightening mechanism. The preferred hexnut includes an integral locking pin which ensures a constant locking torque while enabling the nut to ratchet onto the bolt 54. Hexnuts of this type are available from ANCO.

[0047] The operation of the clamp 100 is similar to that of cable securing mechanism of the cable support system 10. The two hingeably interconnected clamp keepers 14_a, 14_b are tightened by cooperation of the bolt 54 and the nut 104 onto the cable 50. The two clamp keepers 14_a, 14_b define second-class levers that cooperatively act on the cable 50. The fulcrum of the levers is the hinge 102, and the tightening means 54, 104 supplies the applied force which draws the tightening portions 26_a, 26_b together about the hinge 102 to act on the load cable 50 which is interposed between the fulcrum and the applied force.

[0048] The suspension clamp 100 further includes a connection region 106 (FIG. 11) comprising a half-loop cooperatively defined by the tightening regions 26_a, 26_b and the bolt-and-nut fastener 54, 104. An associated suspension loop or other associated connecting element (not shown) connects with the connection region 106 for suspending the suspension clamp 100 from an overhead structure.

[0049] The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.