Luminaire

Feb. 14, 1939.

2,147,482

Η. E. BUTLER

LUMINAIRE

Filed Dec. 1, 1936

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Inventor:

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Patented Feb. 14,1939

2,147,482

UNITED STATES PATENT OFFICE

2,147,482

LUMINAIRE

Henry E. Butler, Scotia, N. Y., assignor to General Electric Company, a corporation of New York

Application December 1, 1936, Serial No. 113,636

Claims. (CL 240—128)

My invention relates to luminaires, particularly to luminaires in which the light source is surrounded by a translucent enclosure consisting of several parts, and more particularly to a device 5 for holding these parts in juxtaposed position.

One object of my invention is to provide an improved fastening device between parts of luminaire enclosures, whereby the parts are normally held together with a sufficiently large force to 10 overcome the force of wind, but which device will permit a quick separation and reassembly of the parts for relamping or cleaning purposes;

Another object of my invention is to provide a simple fastening device between a receptacle and 15 its cover.

For a better understanding of my invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying draw20 ing, and its scope will be pointed out in the appended claims.

In the accompanying drawing, Fig. 1 is a front elevation in section of a portion of a luminaire provided with an improved fastening means built 25 in accordance with my invention, Fig. 2 is a plan view of the fastening means, Fig. 3 is a fragmentary sectional view of a luminaire provided with a modification of my improved device, and Fig. 4 illustrates an application of my improved device 30 to another form of luminaire.

Referring to the drawing in detail, Fig. 1 illustrates a fragment, in section, of the top of a globe 6. This type of globe is normally used for street lighting luminaires, and is provided with 35 a grooved neck portion 6/over which, in accordance with my invention, a spring collar 7 is sprung into engagement with the neck portion. This collar is provided with a horizontal flange 8 projecting over the end of the neck portion 6 40 of the globe, and carries a series of magnets 9, a plan view of which is shown in Fig. 2. The magnets 9 are a modification of the well-known horse shoe type of magnet, designed especially tc be mounted upon the horizontal flange 8 of the 45 collar 7. The magnets comprise an arc shaped horizontal bar portion 10, the ends of which are turned up to form the pole members II and 12. Several cf the magnets are cemented to the horizontal flange 0 of the collar 7 or may be 50 cemented in some instances directly to the edge of the neck portion of the globe.

The globe S is closed by a canopy 13, which carries a magnetic ring 14, sprung into a groove IS on the inside of the canopy and above a ver65 tical flange 16, having a diameter greater than that of the collar 7. When the globe and canopy are assembled, the canopy is merely placed over the neck portion 6 of the globe, and moves downwardly until the ring 14 engages the magnets 9. The magnets 9 attract the ring and, when the 5 ring contacts the ends of the vertical pole members 11 and 12, exert sufficient force to hold the canopy in place against any normal force exerted by wind pressures. On the other hand, if the canopy need be removed for cleaning pur- 10 poses, or for the purpose of placing new lamps into the globe, the canopy may easily be removed by exerting a greater pull than is encountered during the normal conditions. The advantage of this means of fastening the two parts of a 15 glass enclosure to each other, is that there is a minimum of shadows cast upon the glass by the fastening means, yet sufficient force is exerted to hold the parts in their proper relationship. Furthermore, fastening devices heretofore used 20 for this purpose were provided with screws which engage the surfaces of the glass to hold the rings, or other devices, to the globe. These screws had to be loosened whenever the canopy was removed from the globe, and due to the carelessness of 25 operators, and the varying expansion of glass due to changes in temperatures, caused a high percentage of breakage. In accordance with my invention, this breakage is completely eliminated, besides saving considerable time of the operators 30 when cleaning and relamping the luminaires.

In Fig. 3,1 have illustrated a fragmentary sectional view of a modified form of my improved device. In. this modification, a magnetized ring 17 Is cemented to the top surface of the neck por- 35 tion 6 of the globe 5. The ring 17, and the magnets 9 in Fig. I, may be made advantageously of an alloy of iron, nickel, aluminum and cobalt as set forth in U. S. Patent 1,968,569. This alloy nas the property of retaining indefinitely its mag- 40 netization, and also of being capable of magnetization to a much greater density than alloys hitherto known. The ring 17 is given a thick- ’ ness and width substantially equal to the thickness of the glass of the globe. In view of the 45 ability of this alloy to retain its magnetization, and also to assume a magnetization of greater density than ordinary permanent magnet steels, a ring of the dimensions illustrated can develop sufficient force to hold the canopy in place against 50 normally encountered forces. A second ring 18 of a magnetic material such as soft steel, for example, is cemented to the inner surface of the canopy 19 at the juncture of its annular flang* 26 and the body portion of the canopy. When δβ

3,147,483 the ring 18 is brought into contact with the magnetized ring 17, the flange 26 covers the neck portion of the globe, and the canopy is in its proper relation to the globe. The advantage of this β modified form of my improved device is that it eliminates the use of the supporting ring 7, and thereby interferes less with the projection of light through the globe than the device of Fig. 1.

In Fig. 4 I have illustrated an application Of 10 my invention to a modified form of luminaire in which a metal canopy 22 is suspended from a ceiling. Canopies of this type are usually made of a non-magnetic metal, such as brass, and screws are provided projecting radially from the 15 flange to engage a groove, or holes, in the globes. In applying my invention to this type of luminaire, I substitute a magnetized ring 23 similar to the ring II, for the above mentioned screws and attach a magnetic ring 24, preferably made of 20 soft steel, to the edge of a globe 25. When the magnetic ring 24 is brought into contact with the permanently magnetized member 23 which may be a ring such as ring 17 or a series of magnets, such as magnets 9, attached to the canopy, the 25 globe 25 is held in position just as securely as though the well-known screw type of globe holder were used. The removal of the globe 25 and its replacement, are however greatly facilitated since no time is consumed in turning screws.

Although I have illustrated my invention as applied to glass enclosures of two different types of luminaires, it will be apparent to those skilled in the art that it is equally adaptable to other forms of luminaires and is also adaptable to any 35 receptacle provided with a cover, which it is desired to hold in closed position by a force greater than that of gravity.

The magnetized member such as the ring 17 of Fig. 3 or the magnets 9 of Figs. 1 and 2 may 40 be readily built into, and made a part of the cover, or of the receptacle itself. The receptacle and cover need not necessarily be made of glass, but may be made of other materials such as, for example, any of the synthetic resin materials sold 45 under the trade-marks of “Glyptal” or “Bakelite” or others. The magnetic and magnetized member need not necessarily be separate elements of the cover or of the receptacle, since the entire cover, or the receptacle itself may be made of a magnetic material, and may constitute the 5 magnetic element of the device. It may not be practical to make the magnetized part of the device as a cover or as a receptacle, but such construction is not outside of the scope of my invention. 10