US2873358A

US2873358A - Vapor-tight lamp fixture

Info

Publication number: US2873358A
Application number: US393339A
Authority: US
Inventors: Dunker Josef
Original assignee: Ajem Laboratories Inc
Current assignee: Ajem Laboratories Inc
Priority date: 1953-11-20
Filing date: 1953-11-20
Publication date: 1959-02-10
Anticipated expiration: 1976-02-10

Description

Feb. 10, 1959 J. DUNKER 2,873,358

VAPOR-TIGHT LAMP FIXTURE Filed Nov. 20. 1953 3 Sheets-Sheet 1 INVENTOR (1055/ Dl/N/(EA BY bi 70nd rife/M ATTORNEYS Feb. 10, 1959 BUNKER 2,873,358

VAPOR-TIGHT LAMP. FIXTURE Filed Nov. 20, 1953 S Sheets-Sheet 5 FIG. 8.

34 ATTORNEYS United States Patent '0 VAPOR-TIGHT LAMP FIXTURE Josef Dunker, Detroit, Mich, assignor to Ajem Laboratories, Inc., Detroit, Mich.

Application November 20, 1953, Serial No. 393,339

6 (Jlaims. (Cl. 240-5111) This invention relates to vapor-tight lighting fixtures particularly adapted for use with fluorescenttype lamps. Such fixtures are used for industrial applications where the unit may be exposed to inflammable vapors as in commercial paint spray booths and the like.

The present invention is directed toward the provision of an improved vapor-tight fixture that substantially decreases the cost of maintenance and gives improved service in operation. Vapor-tight fixtures heretofore in use have been difiicult to service and the maintenance has been correspondingly expensive. Generally, to service such a unit it has been necessary to shut down an entire bank of lamps while two men open and repair the defective unit. Some units require either special tools or several different kinds of tools to open and service the units. Moreover, because of the construction of the units, considerable time is required to open and re-seal them. For example, in one typical construction, the following procedure is required to open the fixture for servicing: A number of screws are removed to release an outer frame from the ceiling support and the entire unit is then lowered from the ceiling and supported by chains secured to the ceiling while it is serviced. Several additional bolts or screws must be removed before the fixture can be opened.

The gaskets, usually employed to provide the vaportight seal, cause considerable service ditficulty. Some gaskets are subject to deterioration either by the vapors or condensation or by the heat towhich they are subjected and stick to the adjacent surfaces so that the gaskets are damaged or destroyed when the lamp is opened and must be replaced by new gaskets to avoid danger of defective sealing. If the gasket is not secured to one of the surfaces, it is difiicult to hold itin position while the cover of the fixture is being replaced. It is not satisfactory to secure the gasket in position by adhesive or similar means because of the difilculty of replacing the gasket with a new one.

Moreover, operating difiiculties have been experienced with earlier types of vapor-tight fixtures. These troubles have been caused principally by overheating within the sealed fixture which shortens the life of the transformers, ballasts and starters housed within the fixture. Severe overheating may cause migration of the insulating oil, breakdown of the electrical insulation, and may even result in the formation of an explosive atmosphere within the lighting unit. Also, fluorescent lamps are quite critical as to operating temperature.

The present invention is embodied in a vapor-tight fluorescent lamp fixture that in a large measure overcomes these undesirable characteristics of the earlier units and which is easily serviced and maintained and provides improved operating performance to such an extent as to represent a significant and important advance in this field.

The foregoing and other objects and aspects will be in part pointed out and in part apparent from the following detailed description of a lamp fixture embodying the and is an enlarged partial sectional view similar to that iii present invention considered together with the accompanying drawings in which:

Figure 1 is a perspective view of the lamp fixture with portions of the outer housing cut away to show the internal construction;

Figure 2 is a longitudinal sectional view of the lamp fixture;

Figure 3 is an enlarged transverse sectional view taken along line 3-3 of Figure 2;

Figure 4 is an enlarged partial sectional view showing the relative positions of the sealing gasket, the removable glass cover, and the manually operated latch that holds the cover in position, the view corresponding-to the'lower left-hand portion of Figure 3 but being taken along a different transverse plane;

Figure 5 is a perspective view of the manually operated latch shown in Figure 4;

Figure 6 is an enlarged partial sectional view taken along line 6--6 of Figure 3 showing the arrangement of the hinge pin that supports the cover when the unit is opened;

Figure 7 is a partial sectional view taken along line 7'--7 of Figure 6;

Figure 8 is a View similar to Figure 7 but showing the cover in its open position;

Figure 9 illustrates the manner of removing the hinge pin so that the cover can be removed from the fixture the lances by which the sealing gasket is supported; and

Figure 14 is a partial sectional view showing a modified arrangement of the hinge pin which can be used on fixtures which are to be mounted in walls or ceiling structures formed of thin material such as sheet metal.

The fixture illustrated in Figure 1 of the drawings includes a sheet-metal housing 2 having a rear transformer compartment 4 (see also Figures 2 and 3} of rectangular crossscction formed by a rear wall 6 and contiguous side-walls 8 and 12. These side-walls extend forwardly beyond the transformer compartment 4 and are flared outwardly as indicated at 14 and 16 in Figure 3. A light-reflecting partition 18, formed of sheet metal, is positioned within the housing 2 across the forward face of the transformer compartment 4 and separates the transformer compartment from the lamp compartment 22.

The housing 2 also includes end walls 24 and 26 (Figure 2) and is formed of any suitable sheet material such as rust-proofed steel or the like. The housing may be fabricated by any suitable means, but all scams or joints communicating with or exposed to the ambient atmosphere must be welded or otherwise sealed to form a vapor-tight housing. The front of the lamp fixture is closed by a cover 27 having a glass lens or window 28 that is removably secured to the housing 2 and forms a vapor-tight seal with the housing along a rectangular recess 32 (Figure 3).

The fixture is secured to the supporting structure by an outwardly extending flange 34 which is integral with the housing 2 and extends around the periphery of the fixture.

i The glass window 28 is mounted in a rectangular frame- 36 of a double U-shaped cross-section, as best shown in assesses Figure 4, a seal being formed between the glass and the inner U of the metalframe by conventional means such as by the use of bituminous or rubber base mastic.

The frame 36 is hingedly secured to the housing 2 by'a hinge pin 33 which extends the entire length of the fixture through the interior of the outer U of the U frame .96, and is normally restrained from atrial move ment by the engagement of its ends with opposite wall portions of the rectangular recess 32; of the housing, as shown most clearly in Figures 6 and 9. This hinge pin 3.! preferably is formed of steel wire which will accommodate the bending necessary for removal of the window frame, as will be described later, without taking a permanent set. The pin 33 extends through holes 42; in the ends of the frame 36 and also through holes 44 in hinge brackets 46, which are secured to the inner surface of the recess 32, at spaced intervals along one side of the fixture, and project into the interior of the outer U of the frame 36 through openings in the frame 36, as shown in Figures 6 and 9.

In order to form a vapor-tight seal between the frame 36 and the surface of the recess 32., a tubular gasket 48, which may be woven of asbestos, glass fiber, or other heat-resistant fibrous material, extends around the pe riphery of the recess 32 and is compressed into an elliptical or fiat cross-section between the cover 27 and the recess 32. As best shown in Figure 4, the gasket 4-8 is positioned to form a seal between the metal frame 36 and the recess 32 and also between the glass 23 and the recess 32. The gasket 43 is removably secured to the housing 4 by a series of soaced lances so (Figures 12 and 13) which extend angularly from the surface of the recess 32. These lances are of such length and are so shaped as to extend into the adjacent wall of the gasket 48 but do not penetrate the opposite wall of the gasket even when it is flattened by the pressure of the frame 35.

With this arrangement, the gasket 58 remains in position on the housing 2 when the cover 27 is removed, but can be replaced readily when required merely by moving it longitudinally to release it from the lances t) and pinning a new gasket in place. A woven asbestos gasket I is unaffected by vapors or moisture, does not stick to the adjacent surfaces, and has'resiliency tending to maintain its tubular shape and thus provides an effective seal over long periods of time.

To hold the cover 27 in place and under sutficient pressure to compress the gasket ed, a number of spring clips 52 are mounted on the flange 3 2 and arranged to bear upon the frame 1%. a base/54 (Figures 4 and 5), welded or otherwise secured to the flange 34, and a movable latch 56 that in one position bears against the frame 36 and in a second position is rotated outwardly from the frame, as shown in broken lines in Figure 5. of raised cars 53 which encompass a pair of flat ears 62 which extend from opposite sides of the latch 56 and urge the latch resiliently against the frame 36. The pressure of the clips on the frame is easily and quickly re leased by pulling on the outwardly-extending end portion 64 of the latch 56 until the cars 62 have passed the deadcenter position at which position the resilient force of the cars 58 causes the latch 55 to snap toward the open position shown in broken lines in Figure 5. it will be clear that the spring clips 52 are representative of a large number of manually operable fasteners which are commercially available or may be designed for this purpose. i y

In order to insure that a tight seal is effected around thecov e r 27, the holes .4 in the hinge brackets as are substantially larger than the hinge pin 38 so that all portions of the cover 217 are permitted to move toward and away from the gasket 43 even along the side on which th e hinge pin 38 is positioned. in this particular example, the holes 44 in thehinge brackets 46 are elongated in a Each of the clips 52 includes The base 54 has a pair t vertical direction so as to provide a lost motion linkage with suflicient freedom to insure that the pressure of the clips 52 will force the cover 27 against the gasket 48 with suilicient pressure to form a positive seal. It will be clear that the opening in the hinge brackets need not be in the shape shown but may be round, oval, or of other shape so long as they are large enough to permit the necessary movement.

"in order to remove the cover 27 so that it can be replaced readily in the event the glass pane 23 should crack or be broken, at leastone of the openings d2 in the ends of the frame 35 is larger than the diameter. of the hinge pin 38 so that the pin 38 can be removed to release the cover .27. The manner of removing the cover 27 is best illustrated by Figure 9: the cover 2'? is first opened so that it extends downwardly from the fixture and is supported by the hinge pin 38. One end of the hinge pin 33 is then pulled downwardly, this being possible because the opening 42 in the frame 36 is elongated. When the hinge pin 38 clears the lower surface of the flange 34, it is pulled longitudinally from the fixture (as shown in broken lines in Figure 9) thus releasing the cover 27.

it will be clear that the opening 62 need not necessarily be in the shape of a slot but may be round, oval, etc, so long as sufficient room is provided to bend the hinge pin 38 downwardly far enough tocle ar the flange 34. if a round, oval, crossed-slot opening or the like is used, the lost motion described above as occurring at the hinge brackets 46 may be provided by the openings 42 in the ends of the frame 36.

The transformer 66 and ballast 63 are secured to the rear wall 6 of the housing, suitable precautions being talzon to retain the vapor-tight seal of the housing. Both the transformer and ballast are provided with radiating fins 7t? to dissipate ,any localized heating of these units. Power is supplied to-the-lamp system through a plug and socket assembly '72 to permit disconnecting onefixture Without disturbing the operation of other units on the same circuit. if desired, an explosion-proof or other type switch can be substituted for the plug and socket assembly.

in order to provide easy access to the transformer compartrnent 4 from the front of the fixture, the light reflecting panel 18 is readily removable as illustrated by Figures 2 and ll. At one end, the panel 18 is supported by a panel-extension member 74 that is welded orotherwise secured to two supporting brackets le'and 78 (see also Figure 3) fastened to the walls of the housing. The outer edge of the bracket 74 has an upturned lip which has two elongated openings 82. and 84 that respectively receive two lugs 36 and 8d extending from the inner surface of the light-reflecting panel Eli.

At the opposite end of the fixture a similarly supported panel-extension member 92 is provided with a slot $4 which receives a pivotally-mounted panel-supporting key:

96. This key is connected to an operating member (shown at the left in Figure 2) on the opposite side of the panel i3. This operating member is shown in the form of a slotted head that can be turned by means of a coin or screw-driver, or a suitable lever that can be turned with the fingers can be provided.

To remove the panel 18, the key 96 is rotated to free it from the slot 94 so that the end of the panel 18 can be lowered and moved longitudinally to remove the lugs 86 and $8 from the panel extension member 74.

To prevent the panel 1?: from becoming overheated, which may cause discoloration of the light-reflecting sun face on the front of the panel 18 and also shorten the life of the fluorescent lamps, the surface of the panel 18 is provided with a heat-reflecting coating, for'example of aluminum or light-colored paint or other suitable material. The reflector panel 13 may advantageously comprise a predominantly aluminum plate having an oxidized light-reflecting outer surface and an anodized bright heatreflecting inner surface. The remainder of the interior".

of the transformer compartment is made heat-absorbing as by coating with dark-colored paint to increase the heat dissipation from the housing 2.

Any desired number of fluorescent lamps 98 can be mounted in conventional manner on the front of the panel 13, the sockets 100 for them preferably being mounted on the panel-extension members 74 and 92.

In fixtures to be mounted in sheet-metal wall or ceiling structures, the hinge pin 38 may be extended through the housing 2 as shown in Figure 14. The hinge pin 38 is then accessible from the opposite side of the sheet-metal supporting structure and can be removed by merely pulling'it straight out from the housing.

From the foregoing it will be seen that this vapor-tight fluorescent lamp fixture is well-adapted to attain the ends and objects set forth herein and that it berapidly and economically manufactured from readily available materials by conventional fabrication techniques. The structure obviously can be modified in many different ways to adapt it for each particular application within the scope of the following claims.

I claim:

1. A vapor-tight lighting fixture comprising a housing including an access cover, at least a portion of said housing being pellucid, electrically-operated light-producing means in said housing, hinge means swingably supporting said cover, a resilient sealing gasket extending around the periphery of said cover and being positioned between said cover and the remainder of said housing, and spring biased latch means secured to said housing and arranged to urge said cover against said gasket to provide a vaportight seal around said cover, said hinge means comprising a plurality of hinge brackets secured to the housing and having holes therein, a flexible hinge pin extending the length of the hinge through said holes, said cover engaging said hinge pin at points intermediate said brackets, said pin normally being restrained from axial motion by opposed portions of the housing adjacent opposite ends of the pin, said cover providing clearance near one end of said pin, thereby to enable flexure of said pin to clear one of said opposed portions for axial withdrawal of the pin, said hinge means having sufiicient lost motion therein to permit lateral movement of all portions of said cover toward and away from the remainder of said housing to produce significant deformation of said gasket and form a vapor-tight seal.

2. A lighting fixture as claimed in claim 1 wherein said gasket is an endless loop of tubular material secured to said housing by a plurality of spaced lances each having one end secured to said housing and the other end penetrating the adjacent wall of said gasket at an acute angle and extending into the interior of said gasket and being clear of the inner surface of the opposite wall of said gasket.

3. A lighting fixture as claimed in claim ,1 wherein said cover has a hollow edge portion and said hinge pin extends longitudinally through said hollow edge portion of the cover.

4. A lighting fixture including a housing having one open side, a cover having a hollow edge portion and a glass panel positioned adjacent said open side of the housing, a resilient gasket mounted between said cover and said housing, and hinge means swingably supporting said cover on said housing and including a plurality of hinge brackets having transverse openings therein and positioned on said housing and extending at spaced points into the interior of said hollow edge portion of said cover, and a hinge pin extending throughout the length of said hollow edge portion and through the openings in said brackets, said openings being substantially larger than the diameter of said hinge pin to permit lateral movement of said cover toward and away from said housing, said hinge pin extending beyond at least one end of said cover and being removable therefrom by longitudinal movement along the length of the cover.

5. A vapor-tight lighting fixture comprising a housing including a removable access cover, at least a portion of said housing being formed of light-transmitting material,

an electric light source mounted within said housing, said housing and cover having co-operating seal surfaces extending around near the periphery of the cover and which are in closely adjacent opposed relationship when said cover is closed, a resilient tubular gasket sandwiched between said co-operating seal surfaces when said cover is closed, said gasket being secured to one of said cooperating seal surfaces by a plurality of spaced lances each secured at one end to one of said seal surfaces and the free ends of said lances penetrating the wall of said tubular gasket adjacent to said one seal surface at an acute angle With the free end of each lance being clear of the opposite wall of said gasket, thereby to hold said gasket against said one seal surface when the cover is opened and to permit sandwiching of said gasket between said seal surfaces when the cover is closed without the opposite wall of said gasket engaging the free ends of said lances, and releasable means for holding said cover in closed position.

6. A dustand vapor-tight fluorescent illuminating fixture comprising avapor-tight metal housing forming a chamber having a front open side, a reflector panel having a light-reflecting surface, detachable securing means normally holdiugrsaid reflector panel within said housing with said light-reflecting surface facing said open side and substantially parallel with and spaced inwardly from said open side to divide said housing into separate ballast and lamp chambers within said housing, said ballast chamber being substantially totally enclosed by the rear portion of said housing and by said reflector panel, the rear of said reflector panel having a heat-reflecting surface facing toward the interior of said ballast chamber, electrical ballast means mounted within said ballast chamber in heat-conducting contact with the rear portion of said housing, said ballast means having a plurality of spaced heatradiating fins projecting therefrom, the interior surface of the rear portion of said housing having dark-colored heat-conducting and absorbing surfaces surrounding said ballast chamber to transfer heat rapidly away from said chamber, a plurality of fluorescent lamps in said lamp chamber and parallel with said light-reflecting surface, a gasket disposed about the open side of said housing, and a door having a light-transmitting window closing the open side of said housing and forming a vapor-tight seal with said gasket.

References Cited in the file of this patent UNITED STATES PATENTS 1,903,087 Benjamin et al Mar. 28, 1933 2,122,130 Dahnert June 28, 1938 2,257,232 Flint et al Sept. 30, 1941 2,268,731 Van Bloem Jan. 6, 1942 2,291,495 Beals July 28, 1942 2,413,666 Tuck et a1 Dec. 31, 1946 2,477,957 Briskin Aug. 2, 1949 2,481,531 Phillips Sept. 13, 1949 2,555,089 Keefer May 29, 1951 2,593,513 Jones Apr. 22, 1952 2,678,380 Westby May 11, 1954 FOREIGN PATENTS 634,014 Great Britain Mar. 15, 1950