Electricity: conductors and insulators – Insulators – Combined
Reexamination Certificate
2002-06-16
2004-12-14
Nguyen, Chau N. (Department: 2831)
Electricity: conductors and insulators
Insulators
Combined
C174S176000, C174S179000
Reexamination Certificate
active
06831232
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to composite insulators for electric power distribution systems.
BACKGROUND OF THE INVENTION
Insulators have been made with various materials. For example, insulators have been made of a ceramic or porcelain material. The ceramic and porcelain insulators, however, are heavy and bulky; they require specialized assembly fixtures or processes and are awkward and difficult to handle and ship. The ceramic insulators are brittle and easily chipped or broken.
As noted in application Ser. No. 10/173,386, filed on Jun. 16, 2002, entitled “Composite Insulator for Fuse Cutout,” the disclosure of which is incorporated herein by reference, problems have arisen with electrical insulators. One such problem occurs when electricity flashes directly from a conducting surface to a grounded surface. This phenomenon is referred to as “flashover.” The electricity travel gap between the conducting surface and the grounded surface is called the “strike distance.”
Another problem occurs when the electrical current travels or “creeps” along the surface of the insulator. “Creep” results when the insulator has an inadequate surface distance. This may occur when water, dirt, debris, salts, air-borne material, and air pollution is trapped at the insulator surface and provide an easier path for the electrical current. This surface distance may also be referred to as the “leakage,” “tracking,” or “creep” distance.
Because of these problems, insulators must be made of many different sizes so as to provide different strike and creep distances, as determined by operating voltages and environmental conditions. The strike distance in air is known, thus insulators must be made of various sizes in order to increase this distance and match the appropriate size insulator to a particular voltage. Creep distance must also be increased as voltage across the conductor increases so that flashover can be prevented.
Plastic or polymeric insulators have been designed to overcome some of the problems with conventional insulators. However, none of the prior plastic insulators have solved some or all of the problems simultaneously. For example, polymeric insulators have been made with “fins” or “sheds” which require time and labor for assembly. U.S. Pat. No. 4,833,278 to Lambeth, entitled “Insulator Housing Made From Polymeric Materials and Having Spirally Arranged Inner Sheds and Water Sheds,” the disclosure of which is hereby incorporated herein by reference, discloses a resin bonded fiber tube made through filament winding (Col 5, ll. 15-17) with spiral ribs of fiberglass and resin to support a series of circular “sheds” (Col. 5, ll. 28-31; see also FIG.
1
).
Other insulators require a complicated assembly of metal end fittings. For example, an electrical insulator is disclosed in U.S. Pat. No. 4,440,975 to Kaczerginski, entitled “Electrical Insulator Including a Molded One-Piece Cover Having Plate-like Fins with Arcuately Displaced Mold Line Segments,” the disclosure of which is incorporated herein by reference. However, the insulator of Kaczerginski involves a more complicated assembly of two end pieces and an insulating rod of an undisclosed material. Col. 1, ll. 66-68. Similarly, in U.S. Pat. No. 4,246,696 to Bauer et al., the disclosure of which is incorporated herein by reference, an insulator having a prefabricated glass fiber rod manufactured through a pultrusion process is disclosed. Col. 3, ll. 47-49. Yet, the insulator of Bauer et al. requires a complicated attachment of metallic suspension fittings by fanning out the fiber reinforced stalk or by forcing the fittings on by pressure. Col. 3, line 67 to Col. 4, line 2.
Therefore, there exists a need for simple design that facilitates ease in the manufacture of the many different-sized cutouts and insulators the electrical power industry requires. There also exists a need for a lighter insulator that allows for greater ease in handling and shipping. Further, there exists a need for an insulator, which will not trap water, dirt, debris, salts, and air-borne material and thereby reduce the effective creep distance. Finally, there exists a need for a stronger insulator, which will not chip or break during shipping and handling.
The present invention is directed to overcoming these and other disadvantages inherent in prior-art systems.
SUMMARY OF THE INVENTION
The scope of the present invention is defined solely by the appended claims, and is not affected to any degree by the statements within this summary. Briefly stated, a composite insulator embodying features of the present invention comprises (i) a composite body having at least two connectors, wherein the composite body is coupled to a conductor; and (ii) a housing, wherein the housing is a one-piece housing and the composite body is located inside the housing.
REFERENCES:
patent: 706194 (1902-05-01), McCarthy
patent: 735611 (1903-01-01), Steinberger
patent: 1029207 (1912-06-01), Megahan
patent: 1038473 (1912-09-01), Alsberg
patent: 1116303 (1914-11-01), Locke
patent: 1167125 (1916-01-01), Sloper
patent: 1170723 (1916-02-01), Allerding
patent: 1516585 (1924-11-01), Austin
patent: 1691330 (1928-11-01), Austin
patent: 1717287 (1929-06-01), Warren et al.
patent: 1730327 (1929-10-01), Kempton
patent: 1730716 (1929-10-01), Austin
patent: 1764419 (1930-06-01), Schramm
patent: 1768948 (1930-07-01), Baum
patent: 1865134 (1932-06-01), Plimpton
patent: 1869397 (1932-08-01), Stroup
patent: 1894292 (1933-01-01), Cramer
patent: 1896740 (1933-02-01), Cosseboom
patent: 1942294 (1934-01-01), Kaufmann
patent: 1967654 (1934-07-01), Austin
patent: 1980476 (1934-11-01), Earle
patent: 2017519 (1935-10-01), Waldron
patent: 2049552 (1936-08-01), Walsh
patent: 2155848 (1939-04-01), Taylor
patent: 2174476 (1939-09-01), Pittman et al.
patent: 2221582 (1940-11-01), Hanna
patent: 2246193 (1941-06-01), Smith, Jr.
patent: 2378109 (1945-06-01), Schultz
patent: 2386112 (1945-10-01), Harkins
patent: 2593426 (1952-04-01), Fahnoe
patent: 2606954 (1952-08-01), Baker
patent: 2625498 (1953-01-01), Koch
patent: 2653884 (1953-09-01), Hussey et al.
patent: 2660644 (1953-11-01), Murray et al.
patent: 2723705 (1955-11-01), Collins
patent: 2732423 (1956-01-01), Morrison
patent: 2741294 (1956-04-01), Pancherz
patent: 2744043 (1956-05-01), Ramberg
patent: 2747616 (1956-05-01), Ganahl
patent: 2776332 (1957-01-01), Von Cron
patent: 2789154 (1957-04-01), Peterson
patent: 2821604 (1958-01-01), Wallace
patent: 2848133 (1958-08-01), Ramberg
patent: 2858992 (1958-11-01), Wentz
patent: 2883448 (1959-04-01), Hermann
patent: 2900292 (1959-08-01), Coleman, Jr.
patent: 2905582 (1959-09-01), Coleman, Jr.
patent: 2924643 (1960-02-01), Barnes
patent: 2961518 (1960-11-01), Hermann
patent: 2997529 (1961-08-01), Fink
patent: 3043120 (1962-07-01), Waldron
patent: 3057509 (1962-10-01), Bernd
patent: 3063891 (1962-11-01), Boylan et al.
patent: 3066180 (1962-11-01), Virsberg
patent: 3068133 (1962-12-01), Cilker et al.
patent: 3076053 (1963-01-01), Moussou
patent: 3110758 (1963-11-01), Meier
patent: 3110759 (1963-11-01), Moussou
patent: 3111451 (1963-11-01), Peters
patent: 3116386 (1963-12-01), Sperzel
patent: 3134164 (1964-05-01), Hocks
patent: 3134874 (1964-05-01), Cameron
patent: 3152392 (1964-10-01), Coppack et al.
patent: 3159709 (1964-12-01), Austin et al.
patent: D201133 (1965-05-01), Vose
patent: 3192622 (1965-07-01), Bannerman
patent: 3198878 (1965-08-01), Kaczerginski
patent: 3218517 (1965-11-01), Sankey
patent: 3235688 (1966-02-01), Fink et al.
patent: 3249719 (1966-05-01), Misare et al.
patent: 3260796 (1966-07-01), Hirtzer
patent: 3261910 (1966-07-01), Jacquier
patent: 3282757 (1966-11-01), Brussee
patent: 3296366 (1967-01-01), Bronikowski
patent: 3307137 (1967-02-01), Tordoff et al.
patent: 3323097 (1967-05-01), Tordoff
patent: 3325584 (1967-06-01), Herzig
patent: 3345483 (1967-10-01), Leonard et al.
patent: 3358076 (1967-12-01), Rebosio
patent: 3363174 (1968-01-01), Hudson et al.
patent: 3377420 (1968-04-01), Brown et al.
patent: 3387839 (1968-06-01), Miller et al.
patent: 3429758 (1969-02-01), Young
patent: 3448343 (1
Almgren Victor
Henricks Scott
Schomer Michael J.
Nguyen Chau N.
Nino Adolfo
LandOfFree
Composite insulator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Composite insulator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Composite insulator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3315247