Modular electrical assemblies with pressure relief

Claim 2

An electrical surge arrester assembly, comprising: a plurality of cylindrical surge arrester components arranged substantially coaxially to form a cylindrical stack of components having a longitudinal axis, said components having nonlinear voltage-current characteristics; first and second electrically conductive terminals mounted at opposite respective ends of said stack and electrically coupled to said components, said terminals having radial surface portions substantially concentric with respect to said longitudinal axis; a nonconductive tubular member encompassing said stack longitudinally and crosswise and having first and second opposite ends with radially projecting parts engaging and connected respectively to said radial surface portions of said terminals, said tubular member having sufficient structural strength to apply an axially-directed compressive force by way of said terminals to said arrester components sufficient to maintain electrical contact between said components of said stack and said terminals, said tubular member being a winding having a first plurality of strand portions forming a first layer and a first opening therein and having a second plurality of strand portions forming a second layer and a second opening therein, said first and second openings having substantially the same shape and being substantially aligned to form a common opening providing preformed venting means to facilitate lateral egress therethrough of gaseous products produced by said stack; and a housing encompassing said tubular member and cooperating therewith to at least partially control the expulsion of the gaseous products from the assembly.

Claim 3

The assembly according to claim 1, wherein said housing is resilient.

Claim 4

The assembly according to claim 2, wherein said tubular member is rigid against bending in directions transverse to said longitudinal axis, and further wherein said housing is supported against bending by said tubular member.

Claim 5

The assembly according to claim 3, wherein said tubular member is composed of filamentary material.

Claim 6

The assembly according to claim 4, wherein said filamentary material is comprised of a continuous strand wound a plurality of times to form a generally crisscross pattern in said member.

Claim 7

The assembly according to claim 5, wherein the opening is substantially diamond-shaped.

Claim 8

The assembly according to claim 4, wherein the opening is filled with a fracturable insulating material.

Claim 9

The assembly according to claim 2, wherein said housing encompasses at least part of said terminals and encompasses said stack with an interference fit.

Claim 10

A modular electrical assembly, comprising: a plurality of conductive electrical components, aligned in a column along an axis and having axially directed ends, said electrical components being electrically connected at said axially directed ends; first and second conductive end members located at opposite ends of said column, said end members having shoulder extending radially relative to said axis; and a non-conductive winding wrapped in a predetermined pattern longitudinally and crosswise about said electrical components and said end members, engaging said shoulders, and applying an axially directed compressive force through said shoulders on said electrical components and end members to maintain electrical connection therebetween, said winding having a first plurality of strand portions forming a first layer and a first opening therein and having a second plurality of strand portions forming a second layer and a second opening therein, said first and second openings having substantially the same shape and being substantially aligned to form a common opening for venting gas upon failure of one of said electrical components, said common opening extending completely through said winding radially relative to said axis.

Claim 11

A modular electrical assembly, comprising: a plurality of conductive electrical components, aligned in a column along an axis and having axially directed ends, said electrical components being electrically connected at said axially directed ends; first and second conductive end members located at opposite ends of said column, said end members having shoulder extending radially relative to said axis; and a non-conductive winding wrapped in a predetermined pattern longitudinally and crosswise about said electrical components and said end members, engaging said shoulders, and applying an axially directed compressive force through said shoulders on said electrical components and end members to maintain electrical connection therebetween, said winding having a first plurality of strand portions forming a first layer and a first opening therein and having a second plurality of strand portions forming a second layer and a second opening therein, said first and second openings having substantially the same shape and being substantially aligned to form a common opening for venting gas upon failure of one of said electrical components, said common opening extending completely through said winding radially relative to said axis.

Claim 12

A modular electrical assembly according to claim 9 wherein said openings are filled with fracturable insulating material.

Claim 13

A modular electrical assembly according to claim 10 wherein said fracturable insulating material is epoxy.

Claim 14

A modular electrical assembly according to claim 9 wherein an elastomeric housing coaxially surrounds and frictionally engages said winding.

Claim 15

A modular electrical assembly according to claim 12 wherein said housing has an internal throughbore forming an interference fit with said winding.

Claim 16

A modular electrical assembly according to claim 9 wherein a barrier laterally surrounds said electrical components and is interposed between said electrical components and said winding.

Claim 17

A modular electrical assembly according to claim 9 wherein said electrical components are varistors.

Claim 18

A modular electrical assembly according to claim 15 wherein said varistors are generally cylindrical metal oxide varistors.

Claim 19

A modular electrical assembly according to claim 9 wherein said electrical components are generally cylindrical varistor blocks; and said end members comprise cylindrical inner sections having substantially equal transverse diameters with said varistor blocks.

Claim 20

A modular electrical assembly according to claim 9 wherein each said shoulder comprises a radially extending flange on the respective end member with circumferentially spaced notches therein, said notches receiving portions of said winding to define said pattern, opening radially outwardly relative to said axis and extending through said flanges axially relative to said axis.

Claim 21

A modular electrical assembly according to claim 18 wherein each said end member comprises a reduced diameter section on a side of the flange thereof remote from said electrical components, said winding extending about said reduced diameter section to provide a substantially uniform transverse diameter along the entire axial length of the electrical assembly.

Claim 22

A modular electrical assembly according to claim 19 wherein each said reduced diameter section comprises an internally threaded bore.

Claim 23

A modular electrical assembly according to claim 9 wherein said openings are filled with insulating material.

Claim 24

A modular electrical assembly according to claim 21 wherein said insulating material is grease.

Claim 25

A modular electrical assembly according to claim 9 wherein said pattern is a crisscross pattern and said openings are generally diamond shaped.

Claim 26

A modular electrical assembly according to claim 9 wherein said winding is wrapped about said electrical components and said end members while said electrical components and said end members are axially compressed.

Claim 27

A modular electrical assembly according to claim 9 wherein said winding comprises a plurality of common openings which are discrete and longitudinally segmented.

Claim 28

A surge arrester, comprising: a plurality of generally cylindrical, metal oxide varistor blocks aligned in a column along an axis and having axially directed ends, said varistor blocks being in electrical connection with one another through said axially directed ends; first and second generally cylindrical, conductive terminals at opposite ends of said column, each said terminal having a first axial end in contact with one of said varistor blocks, an opposite second axial end with an internally threaded socket and a shoulder extending radially relative to said axis between said ends, said varistor blocks and said terminals having substantially equal transverse diameters; compression means, wrapped longitudinally and crosswise around said varistor blocks and said terminals in a predetermined crisscross pattern, for applying an axially-directed compressive force through said shoulder on said varistor blocks and said terminals to maintain electrical connection thereof, said compression means including a non-conductive winding having a first plurality of strand portions forming a first layer and first openings therein and a second plurality of strand portions forming a second layer and second openings therein, respective first and second openings having substantially the same shape and being substantially aligned to form common preformed lateral openings in said winding for venting gas upon failure of one of said varistor blocks, said lateral openings extending completely through said winding radially relative to said axis; and elastomeric weathershed means, resiliently enclosing said varistor blocks, for protecting said varistor blocks, said weathershed means having a substantially cylindrical throughbore with a diameter substantially equal to a transverse diameter of said compression means.

Claim 29

A surge arrester, comprising: a plurality of generally cylindrical, metal oxide varistor blocks aligned in a column along an axis and having axially directed ends, said varistor blocks being in electrical connection with one another through said axially directed ends; first and second generally cylindrical, conductive terminals at opposite ends of said column, each said terminal having a first axial end in contact with one of said varistor blocks, an opposite second axial end with an internally threaded socket and a shoulder extending radially relative to said axis between said ends, said varistor blocks and said terminals having substantially equal transverse diameters; compression means, wrapped longitudinally and crosswise around said varistor blocks and said terminals in a predetermined crisscross pattern, for applying an axially-directed compressive force through said shoulder on said varistor blocks and said terminals to maintain electrical connection thereof, said compression means including a non-conductive winding having a first plurality of strand portions forming a first layer and first openings therein and a second plurality of strand portions forming a second layer and second openings therein, respective first and second openings having substantially the same shape and being substantially aligned to form common preformed lateral openings in said winding for venting gas upon failure of one of said varistor blocks, said lateral openings extending completely through said winding radially relative to said axis; and elastomeric weathershed means, resiliently enclosing said varistor blocks, for protecting said varistor blocks, said weathershed means having a substantially cylindrical throughbore with a diameter substantially equal to a transverse diameter of said compression means.

Claim 30

A surge arrester according to claim 26 wherein said openings are filled with insulating material.

Claim 31

A surge arrester according to claim 27 wherein said insulating material is fracturable epoxy.

Claim 32

A surge arrester according to claim 27 wherein said insulating material is grease.

Claim 33

A surge arrester according to claim 27 wherein said insulating material is fracturable.

Claim 34

A surge arrester according to claim 26 wherein said winding is wrapped about said varistor blocks and said terminals while said varistor blocks and said terminals are axially compressed.

Claim 35

A surge arrester according to claim 26 wherein said lateral openings are generally diamond shaped.

Claim 36

A surge arrester according to claim 26 wherein each said shoulder comprises a radially extending flange on the respective terminal with circumferentially spaced notches therein, said notches receiving portions of said winding to define said pattern, opening radially outwardly relative to said axis and extending through said flanges axially relative to said axis.

Claim 37

A modular electrical assembly, comprising: a plurality of conductive electrical components, aligned in a column along an axis and having axially directed ends, said electrical components being electrically connected at said axially directed ends; first and second conductive end members located at opposite ends of said column, said end members having shoulders extending radially relative to said axis; a non-conductive filament winding wrapped in a predetermined pattern about said electrical components and said end members, engaging said shoulders, and applying an axially directed compressive force through said shoulders on said electrical components and end members to maintain electrical connection therebetween, said winding having a first plurality of strand portions forming a first layer and first openings therein and a second plurality of strand portions forming a second layer and second openings therein, respective first and second openings having substantially the same shape and being substantially aligned to form common lateral openings in said winding for venting gas upon failure of one of said electrical components, said lateral openings extending completely through said winding radially relative to said axis; and fracturable insulating material filling said openings.

Claim 38

A modular electrical assembly, comprising: a plurality of conductive electrical components, aligned in a column along an axis and having axially directed ends, said electrical components being electrically connected at said axially directed ends; first and second conductive end members located at opposite ends of said column, said end members having shoulders extending radially relative to said axis; a non-conductive filament winding wrapped in a predetermined pattern about said electrical components and said end members, engaging said shoulders, and applying an axially directed compressive force through said shoulders on said electrical components and end members to maintain electrical connection therebetween, said winding having a first plurality of strand portions forming a first layer and first openings therein and a second plurality of strand portions forming a second layer and second openings therein, respective first and second openings having substantially the same shape and being substantially aligned to form common lateral openings in said winding for venting gas upon failure of one of said electrical components, said lateral openings extending completely through said winding radially relative to said axis; and fracturable insulating material filling said openings.

Claim 39

A modular electrical assembly according to claim 34 wherein said fracturable insulating material is epoxy.

Claim 40

A modular electrical assembly according to claim 34 wherein an elastomeric housing coaxially surrounds and fractionally engages said filament winding.

Claim 41

A modular electrical assembly according to claim 36 wherein said housing has an internal throughbore forming an interference fit with said filament winding.

Claim 42

A modular electrical assembly according to claim 34 wherein said electrical components are varistors.

Claim 43

A modular electrical assembly according to claim 38 wherein said varistors are generally cylindrical metal oxide varistors.

Claim 44

A modular electrical assembly according to claim 34 wherein said pattern is a crisscross pattern and said lateral openings are generally diamond shaped.