Vented fuse module for underground power cable system

Claim 2

A three-part fuse module for high voltage electric power conductors comprising; first and second conductor termination modules and a fuse shielding module, said first and second modules being formed of molded, resilient insulating material and having respectively, generally frusto-conical end surfaces that form water-tight, voltage grading seals with opposed, generally frusto-conical end surfaces of said fuse shielding module, when coupled in operating position therewith, each of said first and second modules having an annular lip portion protruding inwardly from the larger diameter section of their respective end surfaces, said shielding module having a pair of generally annular ridge portions that respectively engage said annular lip portions, thereby to latch said modules together, and gas venting means for releasing gas under pressure from the interior of said fuse module, said gas venting means being disposed adjacent said lip portions and being operable to prevent water from entering the fuse module while gas is vented therefrom, and said gas venting means being formed to define a plurality of spaced-apart passageways through the annular lip portion of at least one of said conductor termination modules.

Claim 3

The invention defined in claim 1 wherein each of said modules is formed of molded resilient insulating material, said fuse shielding module includiNg a relatively rigid wall member that is effective to prevent the generally annular ridge portions thereof from being forced radially outward when gas pressure is developed within the fuse module by failure of a gas-generating fuse mounted therein, whereby such gas pressure is effective to temporarily separate the water-tight seals between said modules due to the outward radial movement of the frusto-conical surfaces of said first and second modules responsive to gas pressure, thereby to vent gas through said passageways.

Claim 4

The invention defined in claim 1 wherein said first and second termination modules are formed of resilient insulating material, and said fuse module is formed of a rigid insulating material, whereby gas pressure developed by a fuse failure is effective to temporarily separate the water-tight seals between said modules due to the outward radial movement of the frusto-conical surfaces of said first and second modules responsive to gas pressure, thereby to vent gas through said passageways.

Claim 5

The invention defined in claim 1 including a relatively rigid clamping member removably mounted over the outside of said first and second conductor termination modules, said clamping member being operable to prevent relative movement between said modules in an axial direction while being freely movable with said modules as an assembly, thereby assuring maintenance of a water-tight sealing relationship between the first and second modules and said fuse shielding module during a gas venting operation even when said modules are moved from a fixed position during such an operation.

Claim 6

The invention defined in claim 4 wherein said clamping member is generally U-shaped in configuration and includes means defining a generally U-shaped slot in each end thereof, said U-shaped slots being adapted to cooperate, respectively, with boss elements on said first and second modules, thereby to maintain the clamping member in operating position with respect to said modules.

Claim 7

A three-part fuse fuse module for high voltage electric power conductors comprising; first and second conductor termination modules and a fuse shielding module, said first and second modules being formed of molded, resilient insulating material and having respectively, generally frusto-conical end surfaces that form water-tight, voltage grading seals with opposed, generally frusto-conical end surfaces of said fuse shielding module, when coupled in operating position therewith, each of said first and second modules having an annular lip portion protruding inwardly from the larger diameter section of their respective end surfaces, said shielding module having a pair of generally annular ridge portions that respectively engage said annular lip portions, thereby to latch said modules together, and gas venting means for releasing gas under pressure from the interior of said fuse module, said gas venting means being disposed adjacent said lip portions and being operable to prevent water from entering the fuse module while gas is vented therefrom, and including four equally spaced-apart passageways formed in each of said annular lip portions, each of said passageways being at least one-sixteenth inch wide over its entire length.

Claim 8

A three-part fuse fuse module for high voltage electric power conductors comprising; first and second conductor termination modules and a fuse shielding module, said first and second modules being formed of molded, resilient insulating material and having respectively, generally frusto-conical end surfaces that form water-tight, voltage grading seals with opposed, generally frusto-conical end surfaces of said fuse shielding module, when coupled in operating position therewith, each of said first and second modules having an annular lip portion protruding inwardly from the larger diameter section of their respective end surfaces, said shielding module having a pair of generally annular ridge portions that respectively engage said annular lip portions, thereby to latch said modules together, and gas venting means for releasing gas under pressure from the interior of said fuse module, said gas venting means being disposed adjacent said lip portions and being operable to prevent water from entering the fuse module while gas is vented therefrom, and including four equally spaced-apart passageways formed in each of said annular lip portions, each of said passageways being at least one-sixteenth inch wide over its entire length.