US 4,729,054 AGranted

Low voltage buried wire isolator

OwnerRobert M. Freshman, Jr.inventor

Life of this patent

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Abstract

A low voltage buried wire isolator for interrupting the metallic path between the common grounding system in a structure and the positive grounding system of the telephone or television cable grounding systems. The isolator comprises a housing having an electrically conductive clamping assembly clamped to the metal ground sheath of the service cable. A high voltage protector such as a gas tube is electrically connected, at one of its ends, to the clamping assembly and is designed to normally prevent the flow of electrical current therethrough which is below a predetermined value. A metal fitting is connected to the other end of the high voltage protector and is operatively electrically connected to at least a pair of signal circuit protectors also mounted within the housing. If a power crossover should occur, the high voltage protector prevents the metal ground sheath from overheating since it is electrically insulated from the cable protective apparatus. If a power surge should occur in the service wire, the signal circuit protectors within the housing prevent damage to the equipment within the dwelling.

Claims2

Dependent claims

A protector unit for a buried cable including a metal grounding sheath surrounding at least two conductive wires, comprising,

a housing having an electrically conductive attachment means which is electrically connected to the metal grounding sheath,
a first voltage protector means in said housing and having an input side and a discharge side and esigned to normally prevent the flow of electrical current therethrough which is below a predetermined value,
a ground terminal in operative electrical contact with said input side of said first protector means, said ground terminal being connected to a grounding circuit,
the discharge side of said first voltage protector means being electrically connected to said attachment means,
a first circuit protector means in said housing and hving an input side and a discharge side, the input side of said first circuit protector means being operatively electrically connected to one of said conductive wires and being designed to provide at least a momentary path to said ground terminal and the grounding circuit when a power surge is experienced in said one conductive wire,
and a second circuit protector means in said housing and having an input side and a discharge side, the input side of said second circuit protector means being operatively electrically connected to the other of said conductive wires and being designed to provide at least a momentary path to said ground terminal and the grounding circuit when a power surge is experienced in said other conductive wire.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/880,277Filed 30 Jun 1986 · continuation in part
Priority: 21 May 1984
Granted: 1 Mar 1988
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H02G 3/081
Distribution boxes; Connection or junction boxes: bases, casings or covers
H02G 3/16
Distribution boxes; Connection or junction boxes: structurally associated with support for line-connecting terminals within the box
H02G 3/22
Installations of electric cables or lines or protective tubing therefor in or on buildings, equivalent structures or vehicles: installations of…
H02G
Installation of electric cables or lines, or of combined optical and electric