US503671A - Incandescent electric lamp - Google Patents

Description

(No Model.) I W. E. IIIQKlEiRSON.

INGA'NDESGENT ELBQTRIO L AMP.-

No. 503,671. Patented Aug. 22, 18 9 3.

WWI- 155555. I I' P W /vm UNITED STATES PATENT OFFICE.

"WILLIAM EMERY NICKERSON, OF CAMBRIDGE, MASSACHUSETTS.

INCANDESCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 503,671, dated August 22, 1893.

Application filed July 1'7, 1893. Serial No.480fl31. (No model.)

To all whom, it may concern:

I Be itknown that 1, WILLIAM EMERY NICK- ERSON, of Cambridge, in the county of MiddleseX and State of Massachusetts, have invented a new and useful Improvement in Incandescent Electric Lamps, of which the following, taken in connection with the accompanying drawing, is a specification.

My invention relates to that class of incandescent electric lamps, in which the neck of the lamp globe is closed air-tight by a fusible cement. It is illustrated in the accompanying drawing, which shows partly in Vertical section and partly in side elevation, a lamp embodying my device.

In the drawing, A represents the globe of an incandescent electric lamp, the neck of which is provided with the shoulder a, upon which rests a disk of mica or other suitable substances D. The diskD serves principally, to support the plug of fusible cement E.

B is the filament, and O C the leading-in wires to which the filament is attached at b I).

G is a brass cap or base, surmounting the neck of the lamp, to which it is secured by plaster in the usual manner. The leadingin wires are attached to the cap by soldering, at c c.

F, is a layer of fusible cement of a diiferent composition from E, and will be described hereinafter.

In a lamp of the class described in this specification, it is necessary to use a cement whose fusion point is so high that it will not melt or eliminate gas or vapor, when the lamp is in operation. A cement of this degree of hardness and infusibility, is liable when exposed to a very low temperature, such as may occur during the winter in cold countries, and sometimes from other causes, to lose its adhesiveness, and become separated from the interior wall of the lamp neck, thereby allowing the lamp to leak. This defect I remedy, by using two layers of cement of different composition and degrees of fusibility and elasticity. The harder and more infusible of these layersI placenext the supporting disk D. This layer is able to resist without melting or elimination of gas, the heat received from the incandescent filament. It may be composed of rosin combined chemically with lime, and made somewhat flexible by the addition of a certain quantity of a suit-able oil, and a.

granular substance, substantially as described in my PatentNo. 500,075,granted June20,1893, for an incandescent electric lamp. The other layer, shown in the drawing at F, may be composed of a similar compound of rosin and lime, but contains a much larger proportion of oil, whereby much greater flexibilityis obtained, so that its adhesiveness is not destroyed by low temperatures, and no separation from the surrounding glass will take place. This effectually prevents the leakage of air into the lamp, in case the layer of harder cement E, should slightly separate from the glass. Should such a separation take place on account of exposure to intense cold, the surface of the cement E and that of the glass will again unite, when subjected to the heat occasioned by burning the lamp. The soft cement F is prevented from causing vapor in the lamp, by the hard layer E which underlies and protects it.

The gist of my invention consists in the use of a layer of comparatively hard and infusible cement next to the disk or vacuum wall of an incandescent lamp, and alay'er of comparatively soft and fusible cement overlying it, for the purpose of preventing the leakage of air into the lamp, when intense cold, or other cause may have made the hard cement to lose its adhesiveness and separate from the surrounding glass.

While my invention applies especially to lamps which are to encounter intense cold, it is also useful under ordinary circumstances, since it enables a much harder and more infusible cement to be used, where there is most danger of fusion and elimination of gas or vapor, thereby producing a superior lamp.

I claim 1. In an incandescent electric lamp, afusible cement plug for closing the neck of the lamp globe air-tight, said plug consisting of two layers, one comparatively hard and infusible, located nearer the filament, and one comparatively soft and fusible, located upon and outside the hard layer, substantially as and for the purpose set forth; v

2. In an incandescent electric lamp, the combination. of the glass globe A having a neck adapted to be closed by a plug of fusible name to this specification, in the presence of cement, the filament B, the leading-in wires two subscribing witnesses, on this 14th clay of C O and the cement-supporting disk D; with July, A. D. 1893.

WILLIAM EMERY NICKERSON. Witnesses:

FRANK G. PARKER,

FRANK G. HATTIE.

the layer of fusible cement E, and the softer 5 and more flexible layer of cement F, substantially as and for the purpose set forth.

In testimony whereof I have signed my

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