Electricity: electrical systems and devices – Safety and protection of systems and devices – High voltage dissipation
Reexamination Certificate
2001-12-12
2004-04-20
Reichard, Dean A. (Department: 2831)
Electricity: electrical systems and devices
Safety and protection of systems and devices
High voltage dissipation
C361S117000, C361S118000, C361S129000, C361S130000
Reexamination Certificate
active
06724605
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention is in the field of over-voltage protection for communication networks and is concerned with the structural design of the power feed elements to the electrodes of a gas-filled surge arrester.
For protection against over-voltages as can occur, among other things, due to lightning strikes, gas-filled surge arresters are employed in communication networks and the appertaining devices that comprise one or two or, respectively, three discharge paths and, for this purpose, are composed of two end electrodes and, potentially, of a further electrode in the form of a middle electrode as well as of one or two hollow-cylindrical ceramic insulators.
In two-electrode surge arresters, the ceramic insulator usually has its end face soldered to the end electrodes (see U.S. Pat. No. 4,266,260 A). In three-electrode surge arresters, the ceramic insulators are soldered at their circumferential end faces to both the middle electrode as well as to a respective end electrode (see U.S. Pat. No. 3,885,203 A and U.S. Pat. No. 4,212,047 A). The contacting of the electrodes at their outer circumference usually occurs either within a housing with the assistance of resilient clamps or with the assistance of leads that have their one end soldered or welded tangentially, radially or axially to a respective electrode and have their other end provided with a pluggable contact element or fashioned for a soldering (see U.S. Pat. No. 4,212,047 and U.S. Pat. No. 4,984,125 A). In order to fashion the power feed elements in gas-filled surge arresters of the higher performance category so that they are also sure to withstand extreme current loads, it is also known to employ power feed elements in the form of a band-like clip that are fixed to the circumference of the surge arrester with a releasable clamp closure. A riveting or an ultrasound welding also come into consideration as a non-releasable clamp closure. In addition, the band-like clips can be fashioned so broad that they embrace not only the electrically conductive foot region of the respective end electrode but also the adjoining ceramic insulator over a respective part of the axial length of the insulator. As a result thereof, the electrical behavior of the surge arrester can be positively influenced (see DE 196 41 385 A1/U.S. Pat. No. 5,768,082 A).
It is also known to arrange additional component parts at the face end of the end electrodes of three-electrode arresters in order to realize a short-circuit device (fail safe mechanisms) and/or in order to connect auxiliary discharge paths electrically parallel to the gas discharge paths. For radial fixing of the component parts, specific designs in the foot region of the end electrodes and a cap that resides under the influence of a spring and is electrically connected to the middle electrode of the surge arrester are employed (see U.S. Pat. No. 5,388,023 A; U.S. Pat. No. 5,633,777 A and U.S. Pat. No. 4,984,125 A/FIG. 1
a
).
SUMMARY OF THE INVENTION
For a gas-filled surge arrester having band-like clips, the invention is based on the object of simplifying the mountability of the band-like clips and to thereby expand their function as far as possible.
For achieving this object, it is first provided that each clip allocated to an end electrode is resiliently fashioned in the circumferential direction. This can be realized, for example, in that clip is provided with a two-leg, clamp-like batter or bend. The clip can also be lent the form of a cap that comprises a hollow-cylindrical edge region and a planar cover region provided with a center opening, whereby the edge region has its circumference provided with a plurality of bead-like impressed portions that lie against the foot part of the respective end electrode. Given such a design of the clip, the electrical terminal of the respective end electrode can be prefabricated in the framework of an automatic manufacturing sequence and can also be slipped onto the respective end electrode. The spring tension of the clip thereby suffices in order to assure a reliable contacting of the respective end electrode given normal and medium current load.
A clip fashioned according to the invention can also exercise other functions when it is utilized for contacting given three-electrode arresters and is fashioned broad enough. In this case, the clip can be put in place on the surge arrester so that the chip projects axially beyond the foot part of the respective end electrode by a certain length. Parts of a short-circuit device electrically connected to the middle electrode can be allocated to this projecting region of the clip, as can, additionally, parts of an auxiliary discharge path connected electrically parallel to the gas discharge path. To this end, a fusion disk and a spacer are arranged within the projecting region of the clip. With a clip with a clamp-like batter or bend, a disk-shaped auxiliary electrode can also be allocated to the clip and has a diameter of at least equal to the outside diameter of the clip. The auxiliary electrode is held spaced from the edge of the clip by the fusion disk and the spacer and is pressed against the spacer by a spring. This spring can be a matter of a known spring clip (see FIG. 1 of U.S. Pat. No. 4,984,125). However, a coil spring or a spring washer can also be employed and is fixed by a U-shaped shackle secured to the middle electrode. In a known way, the spacer holding the disk-shaped auxiliary electrode spaced from the edge of the clip can be an insulating member or—preferably—a varistor (see FIG. 1 of U.S. Pat. No. 5,388,023).
Instead of a disk-shaped auxiliary electrode, a cap-like auxiliary electrode (similar to part 37 of FIG. 3 of U.S. Pat. No. 5,633,777 and part 15 of FIG. 1 of U.S. Pat. No. 5,388,023) can also be provided and is under the influence of a spring clip electrically connected to the middle electrode. The cap-like electrode has an edge projecting into the projecting region of the clip, accepts the fusion disk and the spacer, and is held insulated and spaced from the clip by a ring-like insulator part.
In the case of a clip in the form of a cap, the short-circuit device is formed by the planar cover surface of the cap and by a free end of a spring clip which is connected to the center electrode and which free end engages into the center opening of the cap. The free end of the spring clip is held spaced from the planar cover surface of the cap by means of a fusion disk and the auxiliary discharge path that are arranged within the cap, and the fusion disk or the auxiliary discharge path is insulated from the planar cover surface of the cap by means of an insulating centering member. The auxiliary discharge path is composed of a varistor that is arranged in the cap and insulated from the cap by the insulating centering member. However, a perforated mica folium can also serve as auxiliary discharge path and the fusion disk, which lies thereagainst, is insulated from the cap.
REFERENCES:
patent: 3885203 (1975-05-01), Baker et al
patent: 4212047 (1980-07-01), Napiorkowski
patent: 4266260 (1981-05-01), Lange et al.
patent: 4491893 (1985-01-01), Toda
patent: 4493004 (1985-01-01), Lange et al.
patent: 4984125 (1991-01-01), Uwano
patent: 5142194 (1992-08-01), Jacubeit et al.
patent: 5388023 (1995-02-01), Boy et al.
patent: 5633777 (1997-05-01), Boy et al.
patent: 5768082 (1998-06-01), Lange et al.
patent: 7114566 (1971-04-01), None
patent: 2 103 007 (1972-08-01), None
patent: 27 49 392 (1979-05-01), None
patent: 34 10 610 (1985-09-01), None
patent: 43 18 366 (1994-10-01), None
patent: 44 26 591 (1995-02-01), None
patent: 195 28 140 (1996-11-01), None
patent: 196 41 385 (1997-04-01), None
patent: 0 378 963 (1994-06-01), None
patent: 2 408 211 (1979-06-01), None
Bobert Peter
Boy Jürgen
Epcos AG
Ha Nguyen T.
Reichard Dean A.
Schiff & Hardin LLP
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