04709120 is referenced by 264 patents and cites 12 patents.

An improved underground utility equipment vault is comprised of at least two concentrically disposed chambers. The inner chamber is a non-electrically conductive material such as wood and is disposed in spaced concentric relationship within the outer chamber which is metallic, preferably steel. The exterior surface of the outer chamber is provided with a protective dielectric coating and cathodic protection in the form of sacrificial anodes. The inner chamber is provided with heat vents adjacent its uppermost surface area and cold air returns adjacent its lowermost surface area. The heat vents may be provided with exhaust fans. The inner chamber is provided with above ground air communication and an entryway. The interior of the inner chamber and electric gear therein contained is electrically isolated from the outer chamber and the vault exterior.

Title
Underground utility equipment vault
Application Number
6/871281
Publication Number
4709120
Application Date
June 6, 1986
Publication Date
November 24, 1987
Inventor
Dean C Pearson
870 Golden Meadow Ct., Waukesha, 53186
WI, US
Agent
Willis B Swartwout III
IPC
H02G 3/03
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