Abstract:
Apparatus and methodology for applying heated-air flow to wet or damp copper cable and specifically to individual mutually-insulated copper conductors within that cable including their respective paper sheath coverings. This cable can be used in telecommunications applications. Disclosed embodiments permit drying of difficult to reach wet/damp areas within a cable and between and amongst layers of wet/damp cable. A heat gun muzzle-insert attaches, at one end, to a heat gun barrel&#39;s muzzle end to extend hot air flow from the gun through the insert and through a plurality of tubes attached to its other end, This allows air flow to be pin-pointed at wet/damp areas otherwise not reachable without the tubes. The muzzle-insert attaches via threaded connection and is made from the same material as the gun to have the same thermal expansion characteristic. The hot air flow extender mechanisms can be modularized, each ha mg differently-sized pluralities of tubes.

Description:
BACKGROUND 
       [0001]    A copper wire cable can hold in multiple mutually-insulated copper wires. When those copper wires get wet, at one end of the cable, they can cause performance problems due to leakage and shorts from one wire to another and/or from any of the wet wires to ground. In telecommunication applications, cables are sometimes difficult to reach and, when wet, cannot be readily dried-out. For example, these cables can be used in underground man-holes which are small spaces with challenging configurations and underground wet cables need to be completely dried-out before service can be fully restored. 
         [0002]    Furthermore, inside the outer protective layer of the cable, the mutually-insulated copper wires are also sometimes wrapped in paper sheaths. Paper sheath can absorb water like a sponge and draw it further back into the cable. Although the cable exterior covering can be stripped away up to a certain length (up to the cable choke) whereupon that length of individual mutually-insulated conductors in the cable can be exposed to dry them out, the wet paper sheaths that extend inside the cable beyond the choke under the protective exterior covering of the cable also need to be dried-out. This is difficult to do with conventional air blower techniques. In addition to this specific problem, there are other conditions under which a “rats nest” of copper-wire communication cables can get wet and for which a heated air flow cannot penetrate effectively to dry all wet surfaces. Thus, there is a need for applying heated air to dry-out wet surfaces of conductive copper cable that are hard to reach. Applicant&#39;s embodiments satisfy this need. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1A  is an exemplary schematic diagram of a conventional heat gun which may be used within apparatus of an exemplary embodiment, 
           [0004]      FIG. 1B  is a perspective view of the barrel of the heat gun of  FIG. 1A  showing thread-inside the barrel adjacent its muzzle: 
           [0005]      FIG. 2  is an exemplary schematic diagram of a muzzle-insert holding a number of heated-air flow-extenders, the muzzle-insert. capable of being firmly affixed to the muzzle-end of the barrel of the heat gun of  FIG. 1 ; 
           [0006]      FIG. 3  is a perspective diagram of a portion of one of the heated-air flow-extenders which are shown in the aggregate in  FIG. 2 ; 
           [0007]      FIG. 4  is an end view of the aggregate of heated-air flow-extenders shown in  FIG. 2 , the aggregate being held together, and held inside one end of the muzzle insert, by epoxy or other adhesive material; and 
           [0008]      FIG. 5  is an exemplary schematic diagram of heated-air-flow extenders of  FIGS. 2 and 4  making physical contact with a plurality of electrical conductors exposed outside of their protective cable-exterior. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0009]    In this description,. the same reference numeral in different Figs refers to the same entity. Otherwise, reference numerals of each Fig. start with the same number as the number of that Fig. For example,  FIG. 3  has numerals in the “ 300 ” category and  FIG. 4  has numerals in the “ 400 ” category, etc. 
         [0010]    In overview, preferred embodiments include apparatus and methodology for drying a damp or wet electrical cable which has a number of damp or wet mutually-insulated electrical conductors. Hot air, or heated air, is generated by operation of a heat gun. The heat gun is configured to receive a special mechanism on the muzzle of the heat gun barrel. The mechanism includes a pipe and a number of flexible hot air flow conduits, such as, e.g., plastic tubes (hollow plastic cylinders), which extend outwardly from one end of the pipe. The other end of the pipe is directly, and removably, attached to the muzzle end of the barrel of the heat gun. The far ends of the plastic tubes make physical contact with the wet Conductors at difficult-to-reach areas. In this manner, hot air is applied from the heat gun, through the pipe, and through each of the individual conduits provided by the plastic tubes directly to the targeted wet areas inside the cable, those areas otherwise remaining difficult to reach without usage of this mechanism. 
         [0011]    A preferred apparatus embodiment includes a heat gun having a barrel with a muzzle at the discharging end of the band l and a hot air flow-extender mechanism. The mechanism includes a muzzle-insert having two ends, attachable at one of those ends to the muzzle end of the barrel, the insert forming a conduit having an inner periphery, such as, for example, a pipe. There are a number of flexible tubes, the outsides of the tubes being permanently clumped or held together at one end of each of the tubes. These tubes are encircled at that end by the inner periphery of the pipe conduit located at the other end of the insert, and permit flow of heated air from the heat. gun there-through, thereby exiting from each one of the tubes. The clumped-together tubes, at their clumped-together end, can be permanently fastened inside the pipe conduit to each other and to the inside of the pipe by an adhesive or epoxy. The tubes are flexible, can be made from plastic, and the pipe can be made from metal that is the same as the metal of the heat gun, The pipe can thread into the muzzle end of the barrel if the outside of the pipe and the inside of the barrel have compatible threads and if the outside diameter of the pipe is equal to the inside diameter of the barrel. Or, in another embodiment, the muzzle end of the gun barrel can thread into the pipe if the outside of the barrel and the inside of the pipe have compatible threads and if the outside diameter of the barrel is equal to the inside diameter of the pipe. 
         [0012]      FIG. 1A  is an exemplary schematic diagram of a heat gun  100  which may be used within apparatus, or with methodology, of an exemplary embodiment. This heat gun may be selected from commercially available models although hot air temperatures less than their maximum output capacity are employed with the apparatus and methodology of an exemplary embodiment, Alternatively, heat gun  100  can be a modified commercially-available model with hot air output held to an upper limit, e.g,, 175 degrees Fahrenheit and with on/off, air flow and air temperature controls provided via multi-purpose switch  103 . If commercially-available heat guns are employed, there are controls provided that can independently regulate air temperature and velocity of the air along the heated air path, 
         [0013]    Muzzle  101 , which is the discharging end portion of barrel  107  of the heat gun, is the location from which the heated air is ejected. Heat gun  100  has a handle-grip  102  for grasping by the hand of a service technician (not shown) and a finger-activated control switch  103  fm allowing the technician to activate and control heated air flow out of muzzle 
         [0014]    Finally, heat gun  100  has a power-cord  104  which connects to power plug  105  which is plugged into a power source (not shown) needed for operating the heat gun and for generating the essential heat energy.  FIG. 1B  is a perspective view of the end portion of the barrel of the gun of  FIG. 1A  at the location of its muzzle  101  showing threads  106  inside barrel  107  adjacent its muzzle  101 . 
         [0015]      FIG. 2  is a schematic diagram of an exemplary embodiment of a hot air flow-extender mechanism  200  including ( 11  a muzzle-insert and ( 2 ) a number of hot-air flow-extenders in accordance with principles of an exemplary embodiment. The muzzle-insert  201  is a barrel extension or a pipe and is capable of being firmly affixed to the muzzle portion of barrel  107  of heat gun  100  of FIGS.  1 A/B Muzzle-insert (pipe)  201  can typically be three to six inches long, more or less, with no particular upper limit on pipe length, and can be made from metal and preferably from the same material or metal as the muzzle  101  of heat gun  100 . Pipe  201  has a hollow interior to act as a conduit for hot air flow in direction  108  ( FIG. 1A ) or direction  204  ( FIG. 2 ). Pipe  201  has a threaded exterior  202  comprising a number of threads for threading into, or grasping, other threads  106  shown in  FIG. 1B  which are configured inside barrel  107 . It is preferable that the materials from which pipe  201  and barrel  107  are made have the same, similar, heat expansion characteristics because both pipe and barrel shall expand and contract together as a function of temperature rise and fall. Stability of interconnection, as well as ease of making connection or disconnection, between pipe  201  and barrel  107  may depend on those characteristics. If they are both made from the same material that would eliminate the possibility of one component expanding more than the other. In an alternative configuration, pipe  201  can have a very short length, e.g., about one inch, and be characterized as a ring, rather than a pipe, where the ring material matches the barrel material. 
         [0016]      FIG. 2  also shows a plurality of hot-air flow-extenders  203  which are individual conduits attached to end  205  of pipe  201 . In a particular embodiment flow-extenders  203  may number between forty and  100 , and there can be fewer than forty and more than  100 . These conduits may be made from flexible plastic tubes. A single conduit  203 - 1  is shown in  FIG. 3  which is a perspective diagram of a portion of one tube, i.e., one of the hot-air flow-extenders shown in the aggregate in  FIG. 2 . The output end  301  of tube  203 - 1  is the place from which hot air is expelled and is the point of contact with wet insulation and/or wet paper sheath of a copper cable to which reference was made above. 
         [0017]    In one particular embodiment, these tubes can be made from poly-vinyl-chloride (PVC.) which is capable of handling hot air flowing through its interior up to a limit of approximately 175 degrees Fahrenheit, and possibly higher on an intermittent basis. One possible source of PVC tubing is Plastixs LLC located in Shrewsbury, Massachusetts and there are other sources. Further, the length of these plastic conduits may each be approximately sixteen inches, more or less, and the inner diameters of the conduits may each be approximately one-sixteenth of an inch, more or less. The exact length and inner diameter can vary and, in certain applications, it may be advantageous to have longer or shorter tubing lengths and larger or smaller tubing inner diameters. 
         [0018]    One feature of an exemplary embodiment is that other pipes  201 , of varying lengths, can be prepared in advance with other sized plastic hot air-flow extenders (longer, shorter, thinner conduit, thicker conduit, etc.) so that the pipes with their respective extenders can be modularly interchanged at the end of heat gun  100  to better respond. to a particular wet cable configuration, Simply unscrew one pipe with its bunch of plastic air-flow extenders and screw on a different pipe, possibly of different length, with its different bunch of air-flow plastic extenders. 
         [0019]      FIG. 4  is an end view of the aggregate of the heated-air flow-extenders  203  shown in  FIG. 2 . The view is taken in the direction  204 , looking through pipe  201  from its threaded end. Extenders  203  are shown clumped-together and encircled or enveloped by pipe  201  at end  205 . The cylindrically-shaped exterior surface of each one of the plurality of air-flow extenders  203  (plastic tubes) located inside pipe  201  is glued, epoxied or otherwise bonded via appropriate adhesive to exterior surfaces of abutting or adjacent extenders and/or to the inside of pipe  201 . The result is a singular mass of extender tubes and hardened epoxy clumped-together at one end of those tubes affixed inside pipe  201 , each tube retaining its open conduit characteristic. An epoxy-adhesive in the drawing is shown as cross-hatched space surrounding tubes  203  and, upon curing or hardening, is non-porous or non-permeable. Thus, all air flow is constrained to be only within and through the conduits of plastic flow extenders  203 . 
         [0020]    With respect to the PVC tubing of the particular embodiment noted above, one useful epoxy product is “Epoxy.com Product  4705  Two Component Flexible Adhesive” which provides a tenacious bond to PVC and also bonds to steel, and is rated to retain its adhesive properties at temperatures as high as  250  degrees Fahrenheit when subjected to intermittent exposure. (It is contemplated that the apparatus of an exemplary embodiment would be used intermittently, to achieve a drying effect on a particular wet cable, and not continuously.) This is merely an example of one commercially-available product; other bonding products of other chemical compositions can be used as well. 
         [0021]    Hot air flow-extenders  203  may or may not be limp as a function of their chemical composition when the apparatus is turned-off and not causing air flow through the extenders. In either case, when the apparatus is turned-on and as air flow velocity is increased through extenders  203 , they shall stiffen, or further stiffen. This reaction to air flow is useful for controlling the penetration of at least some of the flow-extenders from the entire group of flow extenders  203  into the core of a wet copper cable (i.e., into the open end of the cable) to reach hard to get at damp/wet areas such as the dampness that may be retained by paper sheath insulation. 
         [0022]    As an aid in envisioning these damp, wet areas, Applicant makes further use of  FIG. 4  by momentarily considering it to alternatively represent a copper wire cable end. That is, a copper wire cable core has mutually-insulated copper wires that might be represented, when viewed on end, by the multiplicity of circular entities  203 , where one might envision ends of copper wires in lieu of the depicted conduits. Thus, although  FIG. 4  is actually intended to be a depiction of one set of ends of plastic conduits included in an exemplary embodiment, nevertheless, a copper wire cable when viewed on end would have mutually-insulated copper wires that might generally resemble the presentation of  FIG. 4 . 
         [0023]    There could be more or fewer copper wires than the number of circles  203  shown in  FIG. 4 , with concomitant less or more open space between the mutually-insulated wires in the copper wire cable as compared with the cross-hatch shown in  FIG. 4 . In other words, the cross-hatch space in  FIG. 4 , which actually represents solid, hardened epoxy or adhesive between plastic tubes  203  could, in addition, be momentarily envisioned as open space if  FIG. 4  were envisioned as an end-view depiction of a copper wire cable. Then, under that transformed and momentary interpretation of  FIG. 4 , some of the tube-conduits  203  of  FIG. 2 , when stiff from hot air flow, if pressed by a technician against and into that open end of a copper wire cable, can slide between the mutually-insulated copper conductors given sufficient cross-hatched open space, and reach the otherwise unreachable wet/damp areas, The wet/damp areas are located under the cable&#39;s protective outer layer and were previously difficult to reach, or were not reachable at all, by drying air applied to that open end of copper wire cable without the extended reach capability provided by individual conduits of the preferred embodiments. 
         [0024]      FIG. 5  is an exemplary schematic diagram of the heated-air-flow extenders  203  of  FIGS. 2 and 4  as they make contact with a plurality of electrical conductors  501 . Conductors  501  can be individually-insulated intact conductors, and/or paper-sheath-stripped conductors, shown outside of their protective cable exterior  502 , both types being depicted identically to enhance clarity of presentation. The electrical cable at end location  504  was earlier referred to as the cable choke. The outer cable protective shield  502 , and other selected cable insulations for individual conductors can be stripped back to the cable choke. location  504 , as shown in  FIG. 5 . Not every electrical conductor necessarily has its insulation stripped back to the cable choke; insulation is stripped only to the extent deemed necessary by a servicing-technician to allow for effective drying of wet conductors by hot air flowing through tubes  203  and blowing onto those wet conductors and surrounding wet areas. 
         [0025]    Electrical conductors  501  are not shown connected to their respective intended terminals or other connections, but it should be understood that each of those conductors extends beyond its depicted length and is routed to its respective conductive-destination, although all electrical conductors could be intentionally disconnected before servicing if deemed desirable by the technician. In  FIG. 5 , pipe  201  is shown with the ends of at least a portion of its embedded (clumped-together) group of flow-extenders  203  touching wet or damp locations between and amongst individual mutually-insulated copper wires  501  and/or individual non-insulated copper wires  501  in the copper wire cable contained within outer protective layer  502 . In other words, hot air contact can be made with some conductors which are intact, with others that have their paper sheath insulation removed, with others that can be stripped to bare copper wire, and if there is yet other insulation involved it can be stripped, or not, on a selective basis by the technician - or with all conductors stripped precisely the same way. 
         [0026]    Hot air flows in direction  503  through individual tubes  203  to individual locations between and amongst wet or damp copper wires  501  for purposes of drying-out those locations. Flow extenders  203  are flexible and, when the ends of the plastic tubes  203  are pressed by the serviceman or technician against the mass of conductors  501  in the vicinity of cable choke  504 , the extenders  203  form curvilinear shapes shown. Flow extenders  203 , when not in operation, can be relatively stiff as shown in  FIG. 2  or can be relatively flexible as shown in  FIG. 3 , depending upon the type, and chemical composition, of plastic used to make those flow extender tubes. 
         [0027]    In the preceding specification, various preferred embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. For example, instead of the heat gun barrel having threads formed inside the barrel, those threads could be formed on the outside of the barrel, where the companion barrel extender pipes would then have threads on their insides. This alternative embodiment may offer a slightly reduced resistance to air flow from the heat gun as compared with the exemplary embodiment described above, For another example, threads can be formed on both the inside and on the outside of the same barrel to accommodate both outside and inside threaded pipe extenders, respectively, where only one extender is used at any given time. 
         [0028]    In addition, other tubing compositions can be used. For example, polyurethane flexible tubing is capable of retaining its operating characteristics up to approximately  165  degrees Fahrenheit, and is available in one-eighth inch outside diameter and one-sixteenth inch inside diameter size from the Freelin-Wade Company located in McMinnville. Oregon, and there are other sources. As a further alternative, nylon tubing can be used which can 
         [0029]    Furthermore, a product resulting from a process of extrusion of any of these, or other, plastic-related materials which would provide an extruded multiplicity of hollow tubes with each of their outside surfaces at the same end of those tubes inherently connected together, such inherent connection thereby providing a functional equivalent to the cross-hatched epoxy of  FIG. 4 , is also contemplated as a workable component of the present invention. Therefore, the specification and drawings are to be regarded in an illustrative rather than restrictive sense.