US2131117A - Globe type explosionproof fixture - Google Patents

Description

Sept. 27, 1938. P. D. PHILLIPS v GLOBE TYPE EXPLOSIO NPROOF FIXTURE Filed Jan. 14, 1955 I III:"

Patented Sept. 27, 1938 PATENT OFFICE I 2,131,117 GLOBE TYPE EXPLOSIONPROOF FIXTURE Paul D. Phillips, Elmhurst, Ill., assignor to Benjamin Electric Mfg. Company, Des Plaines, 111., a corporation of Illinois Application January 14, 1935, Serial No. 1,623

1 Claim.

My invention relates to lighting fixtures.

One of the objects of my invention is to provide an improved explosion-proof fixture which will have high efiiciency and desirable light distribution, with ample strength to withstand the pressure of internal explosions without breaking down or permitting flame, hot gases or sparks to escape and ignite the surrounding atmosphere.

A further object of my invention is to provide such a construction of a type involving the use of a bulb-enclosing globe, having a small reflector inside of the casing for directing light through the globe.

A further object of my invention is to provide improved means for holding the glass globe in the globe holder or guard.

A further object is to provide an explosionproof fixture of the type indicated having an external reflector surrounding the globe.

A further object is to provide improved means for holding the externalreflector on the fixture or guard.

A further object is to provide improved means for effecting a tight connection between the globe and the rest of the fixture.

Further objects and advantages of the invention will be apparent from the description and claim.

In the drawing, in which my invention is illustrated,

Figure 1 is a side elevational view of an explosion-proof fixture, parts being broken away to show the interior;

Fig. 2 is a section on the line 22 of Fig. 1;

Fig. 3 is a section on the line 3-3 of Fig. 1; and

Fig. 4 is an enlarged sectional view of a detail.

Referring now to the drawing in detail, the construction shown comprises an explosion-proof lighting fixture including a metal hood I, a metal supporting and retaining member 2 screwed into the lower part of the hood, a glass glob-e 3 having a tight engagement with the supporting and retaining member 2 and cooperating with the hood I to form a tight enclosure, a socket 4 mounted on the hood I and held therein by the retaining member 2 for supporting a lamp bulb 5 with its light source extending into the glass globe 3, an annular. reflector member 6 mounted on. the supporting member 2 for reflecting light from the light source through the globe 3, a metal supporting guard screw-threaded onto the supporting member 2 for clamping theoutwardly extending annular flange 8 on the globe 3 tightly against the metal supporting member 2, and an external annular reflector member 9 mounted on the guard 1 for reflecting light rays falling thereon coming from the light source through the globe 3.

The socket 4 is a one-piece porcelain socket so constructed as to provide a barrier between the space within the globe 3 and the upper part of the hood so that explosions originating in either space cannot be transmitted to the other.

In order to effect a tight engagement, the an-- nular flange III on the one-piece socket is provided with a gasket construction, including an asbestos washer I I held in place on the flange by means of an aluminum band I2 spun over the flange ID on the socket. When the retaining member 2 is screwed tightly into the hood, it effects a seal adjacent the annular flange I0 on the socket, due to the gasket construction. A removable inspection plug I2a. may be provided for access to the wiring terminals.

In order to position the socket in the hood, the socket is provided with a groove I3 cooperating with a rib I4 on the hood. A set screw I5 is provided for preventing the supporting member 2 from becoming unscrewed. The internal annular reflector 6 may be of any suitable type, that shown being an aluminum reflector secured to the supporting member 2 by means of screws I6.

In order to provide a tight seal between the glass globe 3 and the supporting member 2, the lower edge of the metal supporting member 2 is finished smoothly and the upper face of the flange 8 on the globe is ground on that portion which engages the supporting member. The gask-et construction at this point comprises an asbestos washer I! (Fig. 4) held in place on the.

flange 8 by means of a metal band I8 spun over and springs outwardly into an annular recess 20 below the threaded portion of the guard.

The external reflector member 9 may be of any suitable type, that shown being porcelain enameled steel with a white inside reflecting surface.

This is held in place on the guard by means of I an annular clamping band 2| which embraces annular beads 22 and 23 (Fig. 1) on the guard and reflector member, respectively. This clamping band may be tightened up by means of a screw 24 swiveled in alug 25 on one end of the band 2| and threaded into a lug 26 secured to the other end of the band. I

In use, a large portion of the light from the light source passes directly through the lower portion of the globe 3 as a direct cone of light. The portion falling on the internal auxiliary refiector 6 is reflected therefrom outwardly through the globe. The portion passing through the globe and falling on the external reflector 9 is reflected therefrom in such a way as to give a generally spread light beam. The light distribution is such as to give a high efiiciency and a desirable spread. The construction is such that the fixture has ample strength to withstand the high pressures of internal explosions without breaking down or permitting flame, hot gases or sparks toescape and ignite the surrounding atmosphere.

Further modifications will be apparent to those skilled in the art and it is desired, therefore, thatv the invention be limited only by the prior art and the scope of the appended claim.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

An explosion-proof fixture comprising a hood construction, a cup-like glass globe, a cup-like guard embracing said cup-like globe, a lamp socket mounted in said hood construction for supporting a lamp bulb so that it extends into said globe, said hood construction being provided with an annular skirt member for supporting said cuplike globe and said cup-like guard, said guard 10 having an outwardly-extending annular bead, a reflector surrounding said guard and having an annular bead adjacentand below said guard bead, and a split channeled ring surrounding and emthe guard V PAUL D. PHILLIPS.

bracing both beads for holding the reflector on 15

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