Optical waveguides – Optical transmission cable
Reexamination Certificate
1999-07-21
2001-04-24
Spyrou, Cassandra (Department: 2874)
Optical waveguides
Optical transmission cable
C385S134000, C385S135000, C174S07000A
Reexamination Certificate
active
06222968
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a cable fitting for a light waveguide cable, which is secured to a cable of a high-voltage overhead line and is guided through an insulator in a region of the light waveguide cable down-lead.
A great variety of cable fittings for the acceptance of light waveguide splices and light waveguide excess lengths are known; however, they are mostly not appropriate for secure protection in the case of a down-lead in a high-voltage system. Thus, light waveguide cables, which are referred to a AD (or ALL Dielectric) bracket cables, have recently been bracketed onto cables of high-voltage overhead lines by appropriate means, such as by straps. However, given the down-lead of such a light waveguide cable, difficulties arise regarding the high-voltage values. When the light waveguide cable is bracketed onto a phase cable of the high-voltage overhead lines, it must be particularly assured that a person can safely touch the down-leaded light waveguide cable, as well as the utilized cable fitting. Thus, for example, it is already known from German patent application No. DE 196 48 755 that an insulator, through which the light waveguide cable, or its light waveguide, is guided, can be used on the down-lead of a light waveguide cable that is bracketed onto a phase cable of a high-voltage overhead line. The light waveguide cable covering is thereby stripped and only the light waveguides are guided further, as warranted, together with an envelope that surrounds them. When using traditional cable fittings, these would have to be immediately mounted at a great height on a pole in order to guarantee protection against physical contact and protection against vandalism.
However, this means that large excess lengths of light waveguide cable would have to be arranged in the region of the mounted cable fitting. The excess length must be sufficient in order to carry out splice and service work on the ground. As schematically illustrated in
FIG. 1
, the excess length of this light waveguide cable is arranged in loops which is referred to as an air cable cross, at the cable fitting.
SUMMARY OF THE INVENTION
It is an object of the present invention to create a cable fitting in its embodiment and in its assembly position in the down-lead region of a light waveguide cable used with high voltage overhead lines, wherein assembly work and reachability are improved and wherein protection and safety are increased. This object is inventively achieved in accordance with the invention in a cable fitting comprising a top part and a bottom part having cable admissions and arranged at a distance from each other on a holding device that is to be fastened to the pole of the high-voltage overhead line; a middle part made of half shells with longitudinal seals arranged between the top part and the bottom part; one pipe clamp arranged for sealing between a first end of the middle part and the top part and between a second end of the middle part and the bottom part; seal rings arranged on the inwardly facing side of the pipe clamps; and sealant injectable into the cable admissions.
The invention cable fitting is structured as a connection or branch fitting for a light waveguide cable, wherein the light waveguide cable is bracketed onto a conductor cable of a high-voltage overhead line with the help of a strap. The inventive embodiment which is constructed particularly assembly-friendly for this purpose, can be mounted to a pole at an accessible height and, nonetheless, be protected against vandalism. In a fully dielectric embodiment, too, the inventive cable fitting is appropriate for receiving light waveguide cables that are bracketed onto a phase cable of the high-voltage overhead line. Wood or concrete poles are mainly used in the medium voltage region for the high-voltage overhead line, and the cable fitting is fastened at a height of approximately 2-3 m. In order to sufficiently protect the thin light waveguide cables from vandalism, they are guided in pipes that are destruction-resistant. The housing of the cable fitting and, as warranted, the feeder pipes for the cables are made of fiber glass-reinforced plastic, preferably polyester, or metal, preferably aluminum injection molding. Advantageously, the housing is manufactured in the extrusion process. The cable fitting essentially comprises a cylindrical top part, a cylindrical bottom part and a middle part that is to be inserted in between the top part and the bottom part. The middle part is fashioned from two half shells. The top part and the bottom part are provided with cable admissions at the terminating sides that are asymmetrically arranged, so that they are situated close to the pole after assembly. Thereby, the introduction of the light waveguide cables into the cable admissions of the cable fitting can ensue without significant bending. The middle part of the cable fitting comprises two halves, which are put together after finishing the splice work by using an appropriate, non-hardening sealant, and are inserted between the top part and the middle part. A cylindrical guide part is respectively inserted in the top part and the bottom part. The half shells are aligned at the cylindrical guide part. Advantageously, tear threads, preferably from aramide, together with swelling powder are put into seal regions of the half shells, so that a later opening can be performed assembly-friendly.
Initially, the top part and the bottom part are fastened at the pole during the assembly, whereby a corresponding holding device is provided that can be, in particular, easily fastened to the pole with a tightening strap. Additionally, it is thereby advantageous that the spacing for the middle part is given, given utilization of such a holding device. When sealing, the cable admissions are provided with a corresponding casting compound, such as a flexible polyurethane resin mix for example, and are thereby sealed. In a further embodiment, the sealing can also be performed by injecting sealant into corresponding seal channels of the cable fitting, particularly into the longitudinal seals in the middle region.
In principle, a variety of splice aids, splice holding devices and excess length arrangements can be utilized in the interior of the inventive cable fitting, however, a multi-functional module (MFM) is particularly appropriate therefor. The multi-functional module comprises corresponding holders for light waveguide excess lengths and for light waveguide splices.
Usually, the splice work is carried out on the ground. In accordance with the invention, a specific advantage result from the low assembly height, so that only relatively small excess lengths need to be accommodated. Thereby, the previous known accumulation of excess lengths at what is referred to as the air cable cross at a high height at the pole is no longer necessary. The assembly of the entire system can also be carried out in a simple manner, whereby the following assembly sequence results. Initially, the protection pipes are fastened to the pole and the light waveguide cable that is to be down-leaded is inserted into the protection pipes. The top part and the bottom part are then mounted onto the pole, preferably with the corresponding holding device. Given assembly with the corresponding holding device, the necessary spacing for the middle part is automatically given. Alternatively, the top part and the bottom part must be mounted at the necessary spacing given assembly without a holding device. The light waveguide cable is then stripped, the corresponding light waveguides are spliced, the splices are deposited in the splice holder, and the light waveguide excess lengths are inserted. In a further assembly step, the sealant is applied in the seal regions of the middle part and the half shells are put together. The locking and the sealing of the middle part relative to the top part or the bottom part ensue by closing the pipe clamps, whereby the circumferential seals are pressed in. Finally, the inputs and outputs are filled up with sealant. If requir
Dotzer Peter
Mayr Ernst
Boutsikaris Leo
Schiff & Hardin & Waite
Siemens Aktiengesellschaft
Spyrou Cassandra
LandOfFree
Cable fitting for a light waveguide cable, which is secured... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cable fitting for a light waveguide cable, which is secured..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cable fitting for a light waveguide cable, which is secured... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2500441