US 5,534,664 A · Explosion proof power supply enclosure for hazardous atmosphere lighting systems

Abstract

An explosion proof power supply enclosure for hazardous atmosphere lighting systems having multiple, identical explosion proof inlet and outlet openings to handle both high voltage AC circuits and low voltage DC intrinsically safe circuits. Each enclosure has thick, flat metal plate end walls and a plurality of identical circular openings located side-by-side in such walls. Each opening has an internal smooth walled surface configuration defining one side of a flame-quenching path. For AC power connections, explosion-proof receptacles are fitted in some of the openings with each receptacle having external surface configurations that define the other side of the flame quenching path. For intrinsically safe circuit conductors, other openings are fitted with adaptors having identical external surface configurations defining flame quenching paths and the adaptors have a variety of electrical and mechanical mechanisms controlling access to the enclosures; three examples of such mechanisms are given as a solid plug, intrinsically safe receptacles and a switch actuating plunger.

Claims8

Dependent claims

An explosion proof enclosure for electrical components used in hazardous atmospheres comprising:

a U-shaped metal plate having a horizontal section comprising the bottom wall of the enclosure, and two horizontally spaced vertical sections comprising opposed side walls of the enclosure;
two thick rectangular metal plates welded inside the ends of the U-shaped plate, comprising opposite vertical end walls of the enclosure, the height of the end walls exceeding that of the side walls;
a pair of rectangular bars welded to the tops of the side walls and to corresponding ends of the end walls, the top surfaces of said bars and end walls being horizontally coplanar having substantially the same horizontal thickness and comprising a rectangular rim for said enclosure;
a rectangular cover plate and means for fastening said plate to the rim;
and
a plurality of identical circular openings extending through said vertical end walls, each opening comprising a bore and a counterbore with a shoulder therebetween defining one side of a flame-quenching path, the total length of which is a minimum 3/4" measured axially along the bore and counterbore and radially along the shoulder.

3 more elements

Dependencies are inferred from the claim text.

Explosion proof power supply enclosure for hazardous atmosphere lighting systems

Life of this patent

Explosion proof power supply enclosure for hazardous atmosphere lighting systems

Life of this patent

Abstract

Claims8