Spark-gap device

Claim 2

A spark-gap device suitable for providing transient protection to a line above a predetermined voltage level, said device comprising: a first and second aligned conductive end electrode means, and hollow enclosure means therebetween, said electrode means extending into said hollow enclosure means in opposed relation, and a third electrode means disposed between said first and second electrode means and supported by said enclosure means, said third electrode means comprising a solid conductive disc provided with a direct passage therethrough providing a lineof-sight path between said first and second electrode means, said disc having lateral faces exposed in facing, longitudinal juxtaposition with exposed arc-supporting surfaces of said first and second electrode means to provide spark-gaps between said first and second electrode means and said disc, said disc forming an effective barrier between exposed arc-supporting surfaces of said first and second electrode means except for said passage so that said disc becomes invoLved in arc discharges which occur in said device, said end electrode means, said disc and said hollow enclosure means being joined to provide closed chambers between said end electrode means and said disc joined by the passage in said disc.

Claim 3

A spark-gap device suitable for providing transient protection to a line above a predetermined voltage level, said device comprising: hollow cylindrical insulating spacer means open at opposite ends thereof, a first conductive electrode which is substantially cup-shaped in overall configuration having a radial flange at its first end extending over and joined to a first end of said insulating spacer means, the second end of said conductive electrode being closed and disposed within said spacer means to provide an exposed lateral arc-supporting end surface within said spacer means oriented longitudinally inwardly thereof, a second conductive electrode which is substantially cup-shaped in overall configuration having a radial flange at its first end extending over and joined to the second end of said insulating spacer means, the second end of said second conductive electrode being closed and disposed within said spacer means to provide an exposed lateral arc-supporting end surface within said spacer means oriented longitudinally inwardly thereof toward the second end of the first electrode, and a conductive solid disc peripherally supported by said spacer means and positioned between second ends of said conductive electrodes, said disc having a central axial bore providing a passage exposing said arc-supporting end surfaces to one another, said disc having its opposite lateral faces exposed in facing juxtaposition to substantially parallel exposed arc-supporting end surfaces of said first and second conductive electrodes to provide longitudinal gaps between the lateral faces of said disc and said first and second conductive electrodes.

Claim 4

A spark-gap device suitable for providing transient protection to a line above a predetermined voltage level, said device comprising: hollow cylindrical insulating spacer means open at opposite ends thereof, a first conductive electrode which is substantially cup-shaped in overall configuration having a radial flange at its first end extending over and joined to a first end of said insulating spacer means, the second end of said conductive electrode being closed and disposed within said spacer means to provide an exposed lateral arc-supporting end surface within said spacer means oriented longitudinally inwardly thereof, a second conductive electrode which is substantially cup-shaped in overall configuration having a radial flange at its first end extending over and joined to the second end of said insulating spacer means, the second end of said second conductive electrode being closed and disposed within said spacer means to provide an exposed lateral arc-supporting end surface within said spacer means oriented longitudinally inwardly thereof toward the second end of the first electrode, and a conductive solid disc peripherally supported by said spacer means and positioned between second ends of said conductive electrodes, said disc having a central axial bore providing a passage exposing said arc-supporting end surfaces to one another, said disc having its opposite lateral faces exposed in facing juxtaposition to substantially parallel exposed arc-supporting end surfaces of said first and second conductive electrodes to provide longitudinal gaps between the lateral faces of said disc and said first and second conductive electrodes.

Claim 5

A spark-gap device suitable for providing transient protection to a line above a predetermined voltage level, said device comprising: a first cylindrical insulating spacer provided at first end thereof with a first conductive electrode which is substantially cup-shaped in overall configuration having a radial flange at its first end extending over and joined to the first end of the first insulating spacer, the second end of said conductive electrode being closed and disposed within said spacer to provide an exposed lateral arc-supporting end surface within said spacer oriented longitudinally inwardly thereof, a second cylindrical insulating spacer axially aligned with the first spacer and provided at a first end thereof with a second conductive electrode which is substantially cup-shaped in overall configuration having a radial flange at its first end extending over and joined to the first end of the second insulating spacer, the second end of said second conductive electrode being closed and disposed within said second spacer to provide an exposed lateral arc-supporting end surface within said spacer oriented longitudinally inwardly thereof toward the second end of the first electrode, and a conductive solid disc peripherally joined to said first and second spacers at second ends thereof, said disc having a central axial bore providing a passage exposing said arc-supporting end surfaces to one another, said disc having opposite lateral faces exposed in facing juxtaposition to substantially parallel exposed arc-supporting end surfaces of said first and second conductive electrodes to provide longitudinal gaps between the lateral faces of said disc and said first and second conductive electrodes, said electrodes, said disc and said spacers being peripherally joined to provide hermetically sealed chambers between said electrodes and said disc joined by the bore in said disc.

Claim 6

A spark-gap device suitable for providing transient protection to a line above a predetermined voltage level, said device comprising: a first cylindrical insulating spacer provided at first end thereof with a first conductive electrode which is substantially cup-shaped in overall configuration having a radial flange at its first end extending over and joined to the first end of the first insulating spacer, the second end of said conductive electrode being closed and disposed within said spacer to provide an exposed lateral arc-supporting end surface within said spacer oriented longitudinally inwardly thereof, a second cylindrical insulating spacer axially aligned with the first spacer and provided at a first end thereof with a second conductive electrode which is substantially cup-shaped in overall configuration having a radial flange at its first end extending over and joined to the first end of the second insulating spacer, the second end of said second conductive electrode being closed and disposed within said second spacer to provide an exposed lateral arc-supporting end surface within said spacer oriented longitudinally inwardly thereof toward the second end of the first electrode, and a conductive solid disc peripherally joined to said first and second spacers at second ends thereof, said disc having a central axial bore providing a passage exposing said arc-supporting end surfaces to one another, said disc having opposite lateral faces exposed in facing juxtaposition to substantially parallel exposed arc-supporting end surfaces of said first and second conductive electrodes to provide longitudinal gaps between the lateral faces of said disc and said first and second conductive electrodes, said electrodes, said disc and said spacers being peripherally joined to provide hermetically sealed chambers between said electrodes and said disc joined by the bore in said disc.

Claim 7

The device according to claim 3 wherein said disc has a first thickness extending within said spacers providing said opposite faces in juxtaposition with said exposed arc-suppoRting end surfaces, said disc having a peripheral portion of reduced thickness between and joined to said spacers, with said disc just inwardly from said peripheral portion defining a shoulder adjacent joints formed between said peripheral portion and said spacers.

Claim 8

The device according to claim 4 wherein said disc is further provided with an axial flange at the outer edge of said peripheral portion of reduced thickness, said axial flange extending adjacent and over a portion of at least one of said cylindrical insulating spacers.

Claim 9

The device according to claim 3 wherein said central axial bore in said disc has a diameter between approximately one-third and three-fourths of the diameters of said end surfaces of said conductive electrodes.

Claim 10

The device according to claim 3 wherein the second ends of said first and second conductive electrodes providing said arc-supporting end surfaces are substantially planar over the major portion thereof.

Claim 11

The device according to claim 3 wherein the second ends of said first and second conductive electrodes providing said arc-supporting end surfaces are provided with a plurality of small cavities containing low work function material.

Claim 12

The device according to claim 3 wherein the sum of the longitudinal distances between said arc-supporting end surfaces and the lateral faces of said disc along substantially any longitudinal line intersecting said arc-supporting end surfaces is less than the closest longitudinal distance between said arc-supporting end surfaces.

Claim 13

The device according to claim 9 wherein the diameter of the bore in said disc is between approximately one-third and three-fourths of the diameter of the said arc-supporting end surfaces.

Claim 14

The device according to claim 3 wherein the portions of said electrodes between the ends thereof are substantially cylindrical and closely adjacent the cylindrical interior walls of said spacers.

Claim 15

The device according to claim 3 wherein said spacers are formed of ceramic material.