Title of Invention

SPIRAL HANGER FOR A CABLES AND METHOD OF INSTALLING A CABLE USING THE SAME

Abstract

The present invention relates to a spiral hanger for installing a cable along a messenger wire stretched between electric utility poles in such a way that each spiral hanger has (i) a connector half at its one end, the connector half including a forked male terminal with protrusions on its outside and a joint sleeve formed continuously to the terminal, and' (ii) a connector half at its other end, the connector half including a tubular female terminal with holes for engaging the protrusion of the forked male terminal and a joint sleeve formed continuously to the terminal. Besides, the present invention provides a method of hanging a cable from a messenger wire stretched between two electric utility poles. The method comprises the steps of (i) setting spiral hangers on the messenger wire in the vicinity of one of the two electric utility poles and feeding them toward the other pole, the inner diameter of the spiral hangers being larger then the sum of the diameter of the messenger wire and the diameter of the cable, (ii) connecting the following spiral hanger to each spiral hanger fed along the messenger wire by using a male connector half with a joint sleeve and a female connector half with a joint sleeve, and (iii) fixing the spiral hangers to the messenger wire with fixing parts when the first spiral hanger reaches the other pole.

Full Text

FIELD OF THE INVENTION The present invention relates to a spiral hanger for a cable and a method of hanging a cable from a messenger wire with spiral hangers. BACKGROUND OF THE INVENTION 1 The hanger system 100 shown in Fig.14 has been commonly used to hang a cable from a messenger wire. According to the hanger system 100, a cable is installed as follows. As shown in Fig.15, pulleys 121 are first set on a messenger wire 102 stretched between electric utility poles 101a and 101b. Then, a pull rope 122 is passed through the pulleys 121, and the front end of the pull rope 122 is connected to a winch 103. The front end of a cable 114 is connected to the tail end of the pull rope 122, and the winch 103 winds up the pull rope 122 to pass the cable 114 through the pulleys 121. Thereafter, hangers 106 shown in Fig 16 are attached to the messenger wire 102 at intervals of 50-60 cm to hang the cable 114, and the pulleys 121 are removed. All the installation work is made by a worker 104 who dangles in midair between the electric utility poles 101a and 101b as shown in Fig.15 (called "midair dangling work"). Therefore, the worker 104 must be skilled and the work is time-consuming and dangerous. Besides, pulleys 121 can accidentally drop to injure passers-by during installation work. Accordingly, it has been hoped that such problems will be solved. The above hanger systems 100 Is liable to be affected by external factors; accordingly, hangers 106 can fall down or slide sideways, spoiling the proper support of the cable 114 and thereby affecting the characteristics of the cable 114. SUMMERY OF THE INVENTION In view of the above problems, the object of the present invention is to provide (i) a spiral hanger for a cable which does not fall down or slide sideways and (ii) a safe method of hanging a cable with spiral hangers which does not require midair dangling work. To achieve the above object, the present invention provide a spiral hanger having (i) a connector half at its one end, the connector half including a forked male terminal with protrusions on Its outside and a joint sleeve formed continuously to the terminal, and (ii) a connector half at its other end, the connector half including a tubular female terminal with holes for engaging the protrusions of the forked male terminal and a joint sleeve formed continuously to the terminal. Besides, the present invention provides a method of hanging a cable from a messenger wire stretched between two electric utility poles. The method comprises the steps of (i) setting spiral hangers on the messenger wire in the vicinity of one of the two electric utility poles and feeding them toward the other pole, the inner diameter of the spiral hangers being larger than the sum of the diameter of the messenger wire and the diameter of the cable, (ii) connecting the following spiral hanger to each spiral hanger fed along the messenger wire by using a male connector half with a joint sleeve and a female connector half with a joint sleeve, and (iii) fixing the spiral hangers to the messenger wire with fixing parts when the first spiral hanger reaches the other pole. Thus, the method enables the installation of a cable by installation work performed just in the vicinities of electric utility poles. By using the spiral hanger of the present invention, it becomes unnecessary to perform dangerous midair dangling work, and all work can be performed in the vicinity of electric utility poles. Accordingly, the attachment of the spiral hangers serving as cable holders to the messenger wire can be performed safely and easily. Also, the method according to the present invention can eliminate the work of attaching and removing jigs such as pulleys to and from a messenger. Therefore, it has eliminated the possibility of parts dropping and injuring passers-by. According to the method of the present invention, the spiral hangers can be connected easily with the male and female connector halves. Since the spiral hangers are fixed to the messenger wire, the spiral hangers are prevented from sliding or falling. Further, the use of the guide enables the installation of the spiral hangers to be performed promptly, easily and with reliability. The pull-rope leader of the present invention can pull a cable into spiral hangers smoothly and promptly. When the feeder of the present invention is used, not only a spiral hanger of 1000 mm long but also a spiral hanger of 3000 mm long or even of 5000 mm long can be smoothly sent out. Further, the present invention also provides, with male and female connector halves, an advantage of reducing the labor of the connecting work. BRIEF DESCRIPTION OF THE DRAWINGS Fig.1 is a side view schematically showing an embodiment of the method of installing a cable with spiral hangers according to the present invention; Fig.2A is a side view showing an embodiment of the spiral hanger according to the present invention; Fig.2B is a sectional view taken along the line A-A in Fig 2A; Fig.3 is a perspective view of an embodiment of the connector according to the present invention, the connector comprising a male connector half and a female connector half; Fig.4 is a sectional view of a messenger wire, a cable, and the spiral hanger of the present invention wherein the cable is hung from the messenger wire by using the spiral hanger; Fig.5A is an exploded sectional view of an example of the connector of Fig.3, the male and female connector halves-disconnected from each other; Fig.5b is an exploded sectional view of the connector of Fig.SA, the male and female connector halves engaging with each other; Fig.6 is a sectional view showing another embodiment of the male and female connector halves of the present invention; Fig.7 is a front view of a guide for installing spiral hangers on a messenger wire; Fig.8 is a front view of a hanger to prevent installed spiral hangers from falling off the messenger wire while spiral hangers are being installed by using the guide; Fig.9 is a side view showing an embodiment of the guide used when spiral hangers are installed on the messenger wire in the method of the present invention; Fig.10 is an enlarged side view showing an embodiment of a feeder of the spiral hanger of the present invention; Fig.11 is an exploded side view schematically showing an embodiment of a messenger wire and spiral hangers installed on the messenger wire; Fig. 12 is a side view schematically showing a spiral hanger installed on and fixed to a messenger wire with fixing parts in the method of the present invention; Fig. 13 is a side view schematically showing an example of an installation using an embodiment of a pull-rope leader of the present invention; Fig. 14 is a side view showing an embodiment of a pull-rope leader of the present invention; Fig.15 is an exploded side view schematically showing an example of the state in which a cable is hung from a messenger wire by a conventional hanger system; and Fig. 16 is a schematic side view for explaining the conventional hanger system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment of the present invention will now be described in detail with reference to the accompanying drawings. Fig.1 is a side view schematically showing an embodiment of the method of installing a cable with spiral hangers according to the present invention. Fig 2A is a side view showing an embodiment of the spiral hanger according to the present invention. Fig 2B is a sectional view taken along the line A-A in Fig 2A .Fig 3 is a perspective view of an embodiment of the connector according to the present invention, the connector comprising a male connector half and a female connector half. Fig 4 is a sectional view of a messenger wire, a cable, and the spiral hanger of the present invention wherein the cable is hung from the messenger wire by using the spiral hanger. Fig 5A is an exploded sectional view of an example of the connector of Fig 3, the male and female connector halves disconnected from each other. Fig 5B is an exploded sectional view of the connector of Fig 5A, the male and female connector halves engaging with each other. As shown in Fig 1, a messenger wire 2 is previously stretched between electric utility poles la and lb with a winch A worker 4 in a bucket 5 disposed about one meter away from the electric utility pole la sets spiral hangers 6 on the messenger wire 2. As shown in Figs.2A and 2B, the spiral hanger 6 of the present invention comprises a core wire 7 and a sheath 8 of synthetic resin. The spiral hanger 6 is bent in a spiral shape 9 extending in the longitudinal direction and cut in a predetermined length of 75 cm or 100 cm. Although nothing is attached to the front end 10 of the first spiral hanger 6, a female connector half 13b is attached to its tail end 11 through the medium of a joint sleeve 12. Each of the following spiral hangers 6b to 61 has a male connector half 13a on its front end and a female connector half 13b on its tail end as shown in Fig. According, \he spiral hangers 6 to 61 can be connected easily at the site, saving the worker 4 time and labor. As shown in Fig 4, the inner diameter D of the spiral hanger 6 is larger than the sum of the diameter d of the messenger wire 2 and the diameter d' of the cable 14, Preferably, D is 200% or more of the sum of d and d'. Referring now to Figs.SA and 5B, an example of the connector of Fig.3 will be described. The male connector half 13a includes a forked terminal 134 and a joint sleeve 132 formed continuously to each other. The forked terminal 134 has protrusions 133 on its outside. The front end of a spiral hanger 6 (not shown) is fitted into the joint sleeve 132. The female connector half 13b includes a tubular terminal 137 and a joint sleeve 135 formed continuously to each other. The tubular terminal 137 has holes 136 to engage with the protrusions 133 when the forked terminal 134 of the male connector half 13a is fitted into the tubular terminal 137 of the female connector half 13b. The tail end of another spiral hanger 6 (not shown) is fitted into the joint sleeve 135. In the case of this embodiment, one end of a spiral hanger 6 is fitted into the joint sleeve 132 of a male connector half 13a and other end of the spiral hanger 6 is fitted into the joint sleeve 135 of a female connector half 13b. Then, the joint sleeves 132 and 135 are heated to contract and hold both the ends of the spiral hanger 6 firmly. Then, the forked terminal 134 formed continuously with the joint sleeve 132 and having protrusions 133 on its outside is fitted into the tubular terminal 137 of the female connector half 13b of another spiral hanger 6, the protrusions 133 of the former engaging with the holes 136 of the latter. Although preferably the male connector half 13a and the female connector half 13b are made of acetal copolymer, they may be made of metal or an elastic material such as engineering plastics. Fig.6 shows another embodiment of the connector comprising a male connector half 13a and a female connector half 13b. External threads 140 are formed on part of the outer surface of each of the joint sleeves 132 and 135, and provided is a sleeve - like locking part 138 with internal threads 141, which are formed on the inner surface of the locking part 138 to engage with the external threads 140. Besides, the female terminal 137 with holes 136 of the female connector half 13 b may be forked instead of forking the male terminal 134 with protrusions 133 of the male connector half 13a. 1 Fig. 7 is a front view of a guide 16 for installing spiral hangers 6 on a messenger wire 2. Fig. 8 is a front view of a hanger 17 to prevent installed spiral hangers 6 from falling off the messenger wire 2 while spiral hangers 6 are being installed by using the guide 16. Fig. 9 is a side view showing an embodiment of the guide 16 and a feeder 30 used when spiral hangers are installed on a messenger wire 2. Spiral hangers 6 are being installed on the messenger wire 2 from a right electric utility pole toward a left pole. Fig. 10 is an enlarged side view showing an embodiment of the feeder 30 of the spiral hanger. Fig. 11 is an exploded side view schematically showing an embodiment of a messenger wire 2 and spiral hangers 6a and 6b installed on the messenger wire 2. Fig. 12 is a side view schematically showing a spiral hanger 61 installed on the fixed to a messenger wire 2 with fixing parts 18 in the method of the present invention. ' "i The procedure for installing spiral hangers 6 on a messenger wire 2 will now be described below. The guide 16, which serves as a fixed supporting point, is first set on the messenger wire 2 as shown in Fig. 9. As shown in Fig. 7, the guide 16 comprises a ring 16a to let spiral hangers 6 pass through freely and a catcher 16b to catch the messenger wire 2. The catcher 16b includes a base member 161 and a U-shaped member 162, the former having holes to let both the legs of the U-shaped member 162 go through. Threads 163 are formed on an end portion of one of the legs of the U-shaped member 162. The legs of the U-shaped member 162 are inserted from below into the holes of the base member 161 placed on the messenger wire 2, and a nut 164 is screwed from above onto the thread 163 on the end portion .Of the leg to set the messenger wire 2 on a loop portion 165 between the base member 161 and the U-shaped member 162. Spiral hangers 6 are fed through the ring 16a. The guide 16 is set on the messenger wire 2 at the same level so that the ring 16a will be disposed somewhat below the messenger wire 2 and each spiral hanger 6 will enter the ring 16a orthogonally, smoothly. The front end of the first spiral hanger 6 is hung from the messenger wire 2 by using the hanger 17 of Fig. 9. As show in Fig. 8, the hanger 17 comprises a spiral 17a to catch on the messenger wire 2 and a holder 17b to hold the front end of the first spiral hanger 6. Thus, spiral hangers 6 installed on the messenger wire 2 are prevented from coming off the wire 2 and falling. The guide 16 is set on the messenger wire 2, and the end of the first spiral hanger 6a is inserted into the ring 16a of the guide 16 to feed the first spiral hanger 6a toward the electric utility pole lb as shown in Figs. 10 and 11. When the tail end 11a of the first spiral hanger 6a comes to the ring 16a, the front end 10b of the second spiral hanger 6b is connected to the fhail end 11a of the first spiral hanger 6a by the medium of their male and female connector halves 13a and 13b of Figs. 5A and 5B. The above feed and connection are repeated to install spiral hangers 6 on the messenger wire 2. 1 When the front end 10a of the first spiral hanger 6a reaches the electric utility pole lb, the installation of spiral hangers 6a-61 between electric utility pole lb, the installation of spiral hangers 6a-6l between utility poles la and lb is completed, as shown in Figs. 11 and 12. Then, the hanger 17 Is removed and the first and last spiral hangers 6a and 6! are fixed to the messenger wire 2 with fixing parts 18 shown in Fig. 12. Preferably, each of the first and last spiral hangers 6a and 61 is fixed with not a single fixing part 18, but two or three fixing parts 18. 1 As shown in Fig. 9, if a cylindrical guide 19 is installed on the messenger wire 2, between the guide 16 and the bucket 5 for the worker 4 and then a stock holder 20 for stocking 5-10 spiral hangers 6b-6l is set on the messenger wire 2, between the bucket 5 and the electric utility pole la, the worker 4 can install the spiral hangers 6 more easily and quickly by the repetition of the feed and connection procedure. The stock holder 20 has a longitudinal slit (not shown) to facilitate its attachment on and detachment from the messenger wire 2. Further, contrary to Fig.1, Fig.9 shows installation work from the electric utility pole la on the right side to the electric utility pole 1b on the left side. It is convenient to use feeder 30 shown in Fig.10 to feed spiral hangers 6. When a handle 31 is turned clockwise, a universal joint 33 is driven through the medium of a chain 32; accordingly, an upper pinch roller 34a connected to the universal joint 33 is also turned clockwise. A lower pinch roller 34b is pulled up against the upper pinch roller 34a by a spring 35. Thus, a spiral hanger 6 fed into between the upper and lower pinch rollers 34a and 34b is fed forward by turning the handle 31 clockwise. Fig.13 is a side view schematically illustrating the installation of the pull rope by using an embodiment of the pull-rope leader of the present invention. Fig. 14 is a side view showing an embodiment of the pull- rope leader 21 ot the present invention. As shown in Fig. 13, the worker 4 in the bucket 5 positioned near the electric utility pole la using the pull - rope leader 21, sends a pull - rope section 22 into the spiral hangers 6 which are installed on the messenger 2 stretched between poles la and 1b. The structure of the pull-rope leader 21 will now be described in detail. Fig.14 shows the pull- rope leader 21 which comprises a head 23, a pull-rope section 22, a wing assembly 24,a base support 25, and a slider 26. Namely, the pull-rope Ieader21 of the present invention has the cone-shaped head 23 at its frond end, the wing assembly 24 made of plate springs or the like behind the head 23, and pull rope section 22 made of the elastic rigid material at its tail end. The pull-rope section 22 is made of a synthetic resin reinforced by a glass-fiber reinforcement of diameter of 2.5 mm or so (FRP). The pull- rope section 22 may be made of metal or sheathed with a synthetic resin so long as it is rigid and elastic enough to go straight through spiral hangers 6. The base support 25 is to support, and open and close the longitudinally split slider 26. The base support 25 of the present embodiment is provided with a sleeve 27 to hold the front end of the pull - rope section 22 made of metal such as a stainless steel. The slider 26 is made of a thin metal plate, and the same of the present embodiment is made of a thin stainless - steel plate. The pull-rope leader 21 has the cone-shaped head 23. Although the head 23 of the present embodiment is of a rocket type and is made of metal and, it may have any cone - like shape with a pointed tip. Besides, it can be made of any material so long as it has a cone-like shape with a pointed tip. The wing assembly 24 including expanded plate springs 24a or the like is provided behind the head 23. The plate springs 24a are several curved piano wires, which are attached to the rear periphery of the head 23 with silver solder. They are an extension of the rocket-like head. In other works, the wing assembly 24 is an aggregate of a number of slender elements, like a bamboo tea whisk. The wing assembly 24 of the present embodiment includes four plate springs 24a, and the upper two plate springs 24a, carry the base support 25 behind the head 23. The base support 25 may be formed at the rear of the head 23 as a unit with it. Accordingly, when the wing assembly 24 is inserted into an opening with a diameter smaller than that of the expanded plate springs 24a, it is reduced in diameter. When the wing assembly 24 comes out of the opening, the plate springs 24a expand again. The wing assembly 24 reduced in diameter must be able to enter the spiral hangers 6. Besides, the length L of the wing assembly 4 must be longer than one pitch P of the spiral hanger 6 and preferably two pitches. In the case of this embodiment, the slider 26 is provided on the base support 25 as a unit with it so as to catch and slide on the messenger wire 2 of Fig.11 Although the pull - rope section 22 made of an elastic material is connected to the rear end of the base support 25, it may be attached into a hole made in the center of the back of the head 23 directly with adhesive. The slider 26 of the present embodiment has an inner diameter a little larger than the diameter of the messenger wire 2 and is split longitudinally at its top portion so that it can easily be mounted on the messenger wire 2 from below. The pull - rope leader 21 having above structure is inserted through the spiral hangers 6 for a cable. When a back of the spiral hanger is pushed, in this embodiment, the slider 26 slides smoothly on a surface of the messenger wire 2 of Fig. 13. Further, since a tip of the head 23 is pointed, it can move fonA/ard through the spiral hangers 6 for a cable, the outer diameter of the wing assembly 24 being reduced while moving along the inner diameter of the spiral hangers 6, and the pull-rope section 22 is drawn through the spiral hangers 6. When the pull-rope leader 21 arrives at the other of the electric utility poles 1b, the cable 14 (Fig.1) is connected to the tail end of the pull-rope section 22. Then, the pull-rope section 22 is wound by a winch 3 shown in Fig.1, and the cable 14 is pulled through the spiral hangers 6. By the above-described procedures, the method of installing a cable of the present invention is completed. In this embodiment, the cable 14 is directly connected to the pull-rope section 22 of the pull-rope leader 21. Though not shown, however, a pull rope for a cable may be connected and the cable 14 may be further connected to the tail end of the pull rope to draw the cable 14 in. In such a case, when pull ropes are first installed, each using a pull-rope leader 21, between electric utility poles la and 1b, and, through not shown, between the next two electric utility poles, and then both ends of respective ropes are joined, a cable spanning the long distance can be also drawn at a time. Further, when additionally installing a cable, though not shown, the operation can be done similarly by inserting the pull-rope leader 21 through the spiral hangers 6 in which the messenger wire 2 and the cable 14 are already drawn. WE CLAIM 1. A Spiral hanger for hanging a cable from a messenger wire stretched between two electric utility poles, the spiral hanger having,: a connector half at its one end, the connector half including a forked male terminal with protrusions on its outside and a joint sleeve formed continuously to the terminal: and a connector half at its other end, the connector half including a tubular female with holes for engaging the protrusions of the forked male terminal and a joint sleeve formed continuously to the terminal, 2. The spiral hanger for hanging a cable according to claim 1, the spiral hanger having an outer ring for securing the coupling of the forked male terminal with the joint sleeve and the tubular female terminal with the joint sleeve. 3. A method of hanging a cable from a messenger wire stretched between two electric utility poles, the method comprising the steps of: setting spiral hangers on the messenger wire in the vicinity of one of the two electric utility poles and feeding them toward the other pole, the inner diameter of the spiral hangers being larger than the sum of the diameter of the messenger wire and the diameter of the cable: connecting the following spiral hanger to each spiral hanger fed along the messenger wire by using a male connector half with a joint sleeve and a female connector half with a joint sleeve; and fixing the spiral hangers to the messenger wire with fixing parts when the first spiral hangers reaches the other pole, thus the method enabling the installation of a cable by installation work performed just in the vicinity of electric utility poles.

Documents:

070-che-2004-abstract.pdf

070-che-2004-assignement.pdf

070-che-2004-claims filed.pdf

070-che-2004-claims granted.pdf

070-che-2004-correspondnece-others.pdf

070-che-2004-correspondnece-po.pdf

070-che-2004-description(complete) filed.pdf

070-che-2004-description(complete) granted.pdf

070-che-2004-drawings.pdf

070-che-2004-form 1.pdf

070-che-2004-form 19.pdf

070-che-2004-form 26.pdf