Electric overvoltage arresters with improved electrode design

Claim 2

An electric overvoltage arrester for protecting telephone and the like equipment from voltage surges transmitted by lines associated with such equipment, comprising a housing, a pair of spaced electrodes, an insulating spacer separating said pair of electrodes, said housing including means for maintaining said pair of electrodes and said insulating spacer in assembled relationship, said insulating spacer being disposed relative to said pair of electrodes to orient opposing faces of said pair of electrodes in predetermined spaced relation to define an air gap between said opposing faces of said pair of electrodes, at least one of said electrodes having a plurality of grooves in at least one of said opposing faces to define a pattern of grooves and plateau areas, the ratio of each plateau area in said pattern to the combined groove area and plateau area being 0.35 to 0.65.

Claim 3

An electric overvoltage arrester for protecting telephone and the like equipment from voltage surges transmitted by lines associated with such equipment, comprising a housing, a pair of spaced electrodes, an insulating spacer separating said pair of electrodes, said housing including means for maintaining said pair of electrodes and said insulating spacer in assembled relationship, said insulating spacer being disposed relative to said pair of electrodes to orient opposing faces of said pair of electrodes in predetermined spaced relation to define an air gap between said opposing faces of said pair of electrodes, at least one of said electrodes having a plurality of grooves in at least one of said opposing faces to define a pattern of grooves and plateau areas, the ratio of each plateau area in said pattern to the combined groove area and plateau area being 0.35 to 0.65.

Claim 4

An electric overvoltage arrester for protecting telephone and the like equipment from voltage surges transmitted by lines associated with such equipment, comprising a housing, a pair of spaced electrodes, an insulating spacer separating said pair of electrodes, said housing including means for maintaining said pair of electrodes and said insulating spacer in assembled relationship, said insulating spacer being disposed relative to said pair of electrodes to orient opposing faces of said pair of electrodes in predetermined spaced relation to define an air gap between said opposing faces of said pair of electrodes, at least one of said electrodes having a plurality of grooves in at least one of said opposing faces to define a pattern of grooves and plateau areas, the ratio of each plateau area in said pattern to the combined groove area and plateau area being 0.35 to 0.65.

Claim 5

An electric overvoltage arrester as defined in claim 1, wherein the grooves in said one electrode have a depth of at least three times said gap distance between opposing faces of said electrodes.

Claim 6

An electric overvoltage arrester as defined in claim 2, wherein the size of said plateau areas is defined by the diameter of craters formed in the surface of the other of said pair of electrodes and wherein the width of said plateau area to said crater diameter is 0.50 to 1.50.

Claim 7

An electric overvoltage arrester as defined in claim 1, wherein the surface of the other of said pair of electrodes has a plurality of grooves defining a pattern of grooves and plateau areas, wherein the ratio of each plateau area in said pattern to the combined groove area and plateau area is 0.55 to 0.70.

Claim 8

An electric overvoltage arrester as defined in claim 4 wherein said grooves in the surface of said other electrode have a depth not in excess of 1.5 times the width of said grooves.

Claim 9

An electric overvoltage arrester as defined in claim 5, wherein said means comprises a basket having a plurality of projecting tongues to surround and hold said electrodes and said spacer within said housing.

Claim 10

An electric overvoltage arrester as defined in claim 5, wherein said other electrode is a cylindrical carbon electrode, recessed within said insulating spacer, and said one electrode is a disc-shaped electrode, the grooves in said disc-shaped electrode having a depth of 10 to 30 mils and the grooves in said cylindrical electrode having a depth of 6 to 10 mils.

Claim 11

In an electric overvoltage arrester having a housing, a pair of spaced carbon electrodes having a gap space between them, an insulating sleeve disposing said electrodes in spaced apart relationship to define an air gap, and said housing including means for holding said electrodes and said sleeve in assembled relationship, the improvement comprising one of said eleCtrodes being a generally disc-shaped electrode and the other being a generally cylindrical electrode spaced from said disc-shaped electrode, said disc-shaped electrode having substantially flat upper and lower surfaces, the lower surface of which faces said cylindrical electrode and contains a plurality of grooves which define a pattern of grooves and plateau areas, the ratio of each plateau area in said pattern to the combined groove area and plateau area being 0.35 to 0.65, and said grooves in said disc-shaped electrode having a depth of 10 to 30 mils.

Claim 12

In an electric overvoltage arrester having a housing, a pair of spaced carbon electrodes having a gap space between them, an insulating sleeve disposing said electrodes in spaced apart relationship to define an air gap, and said housing including means for holding said electrodes and said sleeve in assembled relationship, the improvement comprising one of said eleCtrodes being a generally disc-shaped electrode and the other being a generally cylindrical electrode spaced from said disc-shaped electrode, said disc-shaped electrode having substantially flat upper and lower surfaces, the lower surface of which faces said cylindrical electrode and contains a plurality of grooves which define a pattern of grooves and plateau areas, the ratio of each plateau area in said pattern to the combined groove area and plateau area being 0.35 to 0.65, and said grooves in said disc-shaped electrode having a depth of 10 to 30 mils.

Claim 13

An electric overvoltage arrester as defined in claim 8, wherein said cylindrical electrode has a surface which forms the gap with the lower surface of said disc-shaped electrode and which has a plurality of grooves defining a pattern of grooves and plateau areas, the ratio of each plateau area in said pattern to the combined groove area and mesa area being 0.55 to 0.70 and the depth of said grooves being 6 to 10 mils.

Claim 14

An electric overvoltage arrester comprising a housing, a pair of spaced carbon electrodes, an insulating spacer separating said electrodes, and means carried by said housing for holding said electrodes and said insulating spacer within said housing, said insulating spacer being disposed relative to said pair of electrodes to orient opposing faces of said pair of electrodes in predetermined spaced relation to define an air gap between said opposing faces of said pair of electrodes, at least one of said electrodes having a plurality of grooves in at least one of said opposing faces to define a pattern of grooves and plateau areas, the ratio of each plateau area in said pattern to the combined groove area and plateau area being 0.35 to 0.65.

Claim 15

An electric overvoltage arrester comprising a housing, a pair of spaced carbon electrodes, an insulating spacer separating said electrodes, and means carried by said housing for holding said electrodes and said insulating spacer within said housing, said insulating spacer being disposed relative to said pair of electrodes to orient opposing faces of said pair of electrodes in predetermined spaced relation to define an air gap between said opposing faces of said pair of electrodes, at least one of said electrodes having a plurality of grooves in at least one of said opposing faces to define a pattern of grooves and plateau areas, the ratio of each plateau area in said pattern to the combined groove area and plateau area being 0.35 to 0.65.

Claim 16

In an electric overvoltage arrester of the type including a housing in the interior of which are disposed a hollow insulating spacer, a first carbon electrode disposed within the spacer, and a second carbon electrode disposed adjacent one end of the spacer with the first and second electrodes having opposed surfaces spaced from each other to define an air gap disposed within a closed chamber defined by the spacer and first and second electrodes, the opposed surface on the second electrode being disposed adjacent the said one end of the spacer, the improvement comprising a plurality of grooves in the opposed surface of the second electrode forming a pattern of individual planar plateau areas separated from each other by the grooves, and cooperating structures on the spacer and the second electrode defining passage means placing the chamber containing the air gap in communication with the interior of the housing, said cooperating structures including at least two spaced ones of said grooves adjacent opposite edges of the second electrode forming spaced projections resting on the end of the spacer and larger than the plateaus, portions of said spaced grooves extending across the end of the spacer to define the passage means and placing the chamber containing the air gap in communication with the interior of the housing at points spaced around the air gap.

Claim 17

In an electric overvoltage arrester of the type including a housing in the interior of which are disposed a hollow insulating spacer, a first carbon electrode disposed within the spacer, and a second carbon electrode disposed adjacent one end of the spacer with the first and second electrodes having opposed surfaces spaced from each other to define an air gap disposed within a closed chamber defined by the spacer and first and second electrodes, the opposed surface on the second electrode being disposed adjacent the said one end of the spacer, the improvement comprising a plurality of grooves in the opposed surface of the second electrode forming a pattern of individual planar plateau areas separated from each other by the grooves, and cooperating structures on the spacer and the second electrode defining passage means placing the chamber containing the air gap in communication with the interior of the housing, said cooperating structures including at least two spaced ones of said grooves adjacent opposite edges of the second electrode forming spaced projections resting on the end of the spacer and larger than the plateaus, portions of said spaced grooves extending across the end of the spacer to define the passage means and placing the chamber containing the air gap in communication with the interior of the housing at points spaced around the air gap.

Claim 18

An electric overvoltage arrester comprising a housing having an open end, a hollow insulating spacer having first and second ends and disposed within the housing with the first end adjacent the open end of the housing, a first carbon electrode disposed within the spacer with one end of the first electrode sealed in the first end of the spacer and with the other end of the first electrode spaced below the second end of the spacer, a second carbon electrode disposed adjacent and closing the second end of the hollow spacer so that the hollow spacer and the first and second electrodes define a closed chamber, said other end of the first electrode and the area of the second electrode adjacent the spacer having opposed surfaces spaced from each other to define an air gap within the closed chamber, and a plurality of grooves in the opposed surfaCe of the second electrode forming a pattern of individual planar plateau areas separated from each other by the grooves, at least one of the grooves having a portion extending transversely across a part of the second end of the spacer to form passage means placing the closed chamber containing the air gap in communication with the housing.

Claim 19

An electric overvoltage arrester comprising a housing having an open end, a hollow insulating spacer having first and second ends and disposed within the housing with the first end adjacent the open end of the housing, a first carbon electrode disposed within the spacer with one end of the first electrode sealed in the first end of the spacer and with the other end of the first electrode spaced below the second end of the spacer, a second carbon electrode disposed adjacent and closing the second end of the hollow spacer so that the hollow spacer and the first and second electrodes define a closed chamber, said other end of the first electrode and the area of the second electrode adjacent the spacer having opposed surfaces spaced from each other to define an air gap within the closed chamber, and a plurality of grooves in the opposed surfaCe of the second electrode forming a pattern of individual planar plateau areas separated from each other by the grooves, at least one of the grooves having a portion extending transversely across a part of the second end of the spacer to form passage means placing the closed chamber containing the air gap in communication with the housing.