Surge-modifying lightning arrester construction

Claim 2

A valve-type lightning arrester construction comprising an elongate housing of insulating material containing a surgedischarge structure which includes a quench-spark-gap portion and at least one block of nonlinear resistance material disposed in series circuit relation between a line terminal at one end of said housing and a ground terminal at the other end of said housing, and surge-modifying means mounted externally on the line terminal end of said housing and coextensive therewith, said surge-modifying means including a casing of insulating material having an elongate cavity therein, a rectilinear throughconductor extending longitudinally through said casing, terminal means at the respective ends of said casing, a nickel-zinc ferrite core disposed within the cavity and surrounding the through-conductor, and means connecting said surge-modifying means in series circuit relation with said surge-discharge structure, said surge-modifying means being effective to inductively alter the current-time relationship of electrical surges discharging from the line terminal to the ground terminal before contacting any part of said discharge structure.

Claim 5

A valve-type lightning arrester construction comprising a pair of elongate, transversely spaced housings of insulating material containing elements constituting a voltage-responsive arc-extinguishing discharge structure including current-limiting silicon-carbide resistors each of which is susceptible to thermal damage by the sudden passage of a current surge therethrough within a predetermined time interval such that time for current deconcentration and heat dispersion from the initial current-carrying channel is unavailable, a first line terminal at one end of one of said housings connected to the discharge structure therein, a second line terminal at the adjacent one end of the other of said housings connected to the discharge structure therein, common ground-terminal means at the respective other ends of said housings connected to the respective discharge structures therein, and an inductive surge-wave modifier mechanically joining and electrically connecting said first line terminal to said second line terminal.

Claim 6

A valve-type lightning arrester construction comprising a pair of elongate, transversely spaced housings of insulating material containing elements constituting a voltage-responsive arc-extinguishing discharge structure including current-limiting silicon-carbide resistors each of which is susceptible to thermal damage by the sudden passage of a current surge therethrough within a predetermined time interval such that time for current deconcentration and heat dispersion from the initial current-carrying channel is unavailable, a first line terminal at one end of one of said housings connected to the discharge structure therein, a second line terminal at the adjacent one end of the other of said housings connected to the discharge structure therein, common ground-terminal means at the respective other ends of said housings connected to the respective discharge structures therein, and an inductive surge-wave modifier mechanically joining and electrically connecting said first line terminal to said second line terminal.

Claim 7

The arrester construction defined in claim 3, in which the inductive surge-wave modifier includes a magnetic core comprising a stacked group of discrete rings of magnetic material.

Claim 8

The arrester construction as in claim 3, wherein the inductive surge-wave modifier includes a magnetic core comprising a stacked group of discrete rings of ceramic ferrite material.

Claim 9

The arrester construction as in claim 3, in which the inductive surge-wave modifier includes a core comprising a stacked group of discrete rings of sintered nickel-zinc ferrite containing a relatively small proportion of the oxides of cobalt and manganese.

Claim 10

A valve-type surge arrester comprising a pair of adjacent elongate insulator housings each containing a similar series circuit assembly of current-limiting resistors and spark gaps, spaced line terminals at one pair of adjacent ends of said housings and spaced ground terminals at the other pair of adjacent ends of said housings, conducting means electrically connecting said spaced ground terminals, and conducting means electrically connecting said spaced line terminals, said last-named conducting means including a saturable inductive surge-wave modifier effective to implement surge sparkover of one of said series circuit assemblies and concurrently facilitate initiation of sparkover of the other of said series circuit assemblies.

Claim 11

A valve-type surge arrester comprising a pair of adjacent elongate insulator housings each containing a similar series circuit assembly of current-limiting resistors and spark gaps, spaced line terminals at one pair of adjacent ends of said housings and spaced ground terminals at the other pair of adjacent ends of said housings, conducting means electrically connecting said spaced ground terminals, and conducting means electrically connecting said spaced line terminals, said last-named conducting means including a saturable inductive surge-wave modifier effective to implement surge sparkover of one of said series circuit assemblies and concurrently facilitate initiation of sparkover of the other of said series circuit assemblies.

Claim 12

A valve-type lightning arrester construction comprising an elongate housing of insulating material, a first conducting line terminal disposed at one end of said housing and a conducting ground terminal disposed at the other end of said housing, and elements constituting a preferential electrical discharge path interposed between said line and said ground terminals, said elements including a plurality of bound silicon carbide blocks subject to thermal damage upon the passage therethrough of a current having a predetermined rate-of-rise, characterized by means effective to reduce the rate-of-rise of current in said silicon carbide blocks, said means including an elongate inductive surge-wave modifier electrically connected and rigidly secured at its inner end to said first conducting line terminal and extending outwardly from said one end of said housing, and a second line terminal electrically connected to the outer end of said inductive surge-wave modifier, said surge-wave modifier including a magnetic core comprising a stacked group of discrete rings of magnetic material.

Claim 13

A valve-type lightning arrester construction comprising an elongate housing of insulating material, a first conducting line terminal disposed at one end of said housing and a conducting ground terminal disposed at the other end of said housing, and elements constituting a preferential electrical discharge path interposed between said line and said ground terminals, said elements including a plurality of bound silicon carbide blocks subject to thermal damage upon the passage therethrough of a current having a predetermined rate-of-rise, characterized by means effective to reduce the rate-of-rise of current in said silicon carbide blocks, said means including an elongate inductive surge-wave modifier electrically connected and rigidly secured at its inner end to said first conducting line terminal and extending outwardly from said one end of said housing, and a second line terminal electrically connected to the outer end of said inductive surge-wave modifier, said surge-wave modifier including a magnetic core comprising a stacked group of discrete rings of magnetic material.

Claim 14

The arrester construction as in claim 8, wherein said stacked group includes rings of ceramic ferrite material.

Claim 15

The arrester construction as in claim 8, in which said stacked group includes rings of sintered nickel-zinc ferrite containing a minor proportion of the oxides of cobalt and manganese.

Claim 16

A valve-type lightning arrester construction comprising a first elongate housing of insulating material having an intermediate terminal member at one end thereof and a ground terminal member at the other end thereof, an insulator coextensive with said housing attached to said first intermediate terminal member and a first line terminal member secured at the outer end of the insulator, a second elongate housing of insulating material secured to said first line terminal member and extending coaxially outward therefrom, and a second line terminal member secured to the outer end of said second elongate housing of insulating material, a voltage-responsive, surge-discharge assembly disposed within said first elongate housing constituting a preferential electrical discharge path between said intermediate terminal member and said ground terminal member, said assembly including at least one block of bound silicon carbide, inductive surge-wave modifying means disposed within said second elongate housing and electrically connecting said line terminal members, and spark-gap means effective to sparkover upon the appearance of a predetermined voltage between (1) either or both of said line terminal members and (2) said intermediate terminal member.

Claim 17

A valve-type lightning arrester construction comprising a first elongate housing of insulating material having an intermediate terminal member at one end thereof and a ground terminal member at the other end thereof, an insulator coextensive with said housing attached to said first intermediate terminal member and a first line terminal member secured at the outer end of the insulator, a second elongate housing of insulating material secured to said first line terminal member and extending coaxially outward therefrom, and a second line terminal member secured to the outer end of said second elongate housing of insulating material, a voltage-responsive, surge-discharge assembly disposed within said first elongate housing constituting a preferential electrical discharge path between said intermediate terminal member and said ground terminal member, said assembly including at least one block of bound silicon carbide, inductive surge-wave modifying means disposed within said second elongate housing and electrically connecting said line terminal members, and spark-gap means effective to sparkover upon the appearance of a predetermined voltage between (1) either or both of said line terminal members and (2) said intermediate terminal member.

Claim 18

The arrester construction as in claim 11, wherein the surge-wave modifying means includes a magnetic core consisting of a stacked group of discrete rings of magnetic material.

Claim 19

The arrester construction as in claim 11, in which the inductive surge-wave modifying means includes a magnetic core comprising a stacked group of discrete rings of ceramic ferrite material.

Claim 20

The arrester construction as in claim 11, wherein the inductive surge-wave modifying means includes a core of nickel-zinc ferrite containing a minor proportion of the oxides of cobalt and manganese, the cobalt oxide not exceeding 3 percent weight and the manganese oxide not exceeding 5 percent weight, based on total percent weight.