US1298299A - Electric incandescent lamp. - Google Patents

Description

J. H. DALE.

ELECTRIC INCANDESCENT LAMP.

APPLICATION FILED IAN. 20.19l5.

Patented M111. 5, 1919.

5] n ma wto'c UNITED STATES PATENT JOHN H. DALE, OF NEW YORK, N. Y., ASSIGNOR TO DATE LIGHTING FIXTURE 00., 1110.,

' A CORPORATION OF NEW YORK- ELECTRIC TNCANDESCENT LAMP.

Specification of Letters Patent.

Application flled January 20,1915. Serial No. 3,198.

To all whom it may concern:

Be it known that I, JOHN H. DALE, a citizen of the United States, residing at the city of New York, in the borough of Man- .hattan and State of New York, have in- .vented certain new and useful Improvements in Electric Incandescent Lamps, of which the following is a full, clear, and exact description.

This-invention relates to electric incandescent lamps, the object being to provide a'construction therefor, which will prevent the conveyance of an injurious amount of heat from the source of light of the lamp to the lamp base. descent lamp ordinarily comprises a metallic shell secured to the glass wall of the lamp by cement or otherwise, the shell inclosing the ends of the leading-1n wlres of the lamp which are soldered to the contact parts associated with, or forming a part of,- the base. The base also sometimes contains insulating material applied to the -conductors and cementitious materials, which are subject to injury by excessive temperatures. In the ordinary or original form of incandescnt lamp, wherein the filament burns in a vacuum, excessive heat 1s not conveyed to the base of the lamp because of the cementing materials in the base and even to melt the solder of the joints thereof. This heating effect in the nitrogen lamp seems to be due to the presence of nitrogen itself, which becoming heated rapidly circulates within the bulb and raises the temperature of the glass walls more rapidly than it can radiate to the external atmoshere. My invention is especially applicable to the nitrogen type of lamp, although not necessarily confined to this lamp, since it may perform a useful function whenever the base of a lamp must be kept at a comparatively low temperature. I accomplish the object of the invention by introducing a The base of an incanportion or skirt 10,

heat insulator between the wall of the lamp and the metallic base, which insulator comprises a vacuum chamber, and in carrying out the invention, I preferably use the wall of the neck of the lamp, as one wall of the vacuum chamber, and provide a special wall or dlaphragm inside of the neck which separates it from the chamber in which the filament element is positioned. The metallic base 1s secured by cement or otherwise to this wall of the neck which forms a part of the vacuum chamber'and is thereby insulated from the heat developed inside of the lamp. vIn the accompanying drawings:

Figure 1 is a vertical-central section of my improved lamp, and

F1g. 2 is a similar view of a lamp showing a" modlfied form of heat insulating vacuum chamber.

The lamp proper comprises the bulb 1, havlng, ascustomary in nitrogen lamps, an elongated integral neck 2. Within the lamp there Is an axial column or post 3, projecting toward the center of the bulb, through which the two leadin wires 4 and 5 extend. These wlres pro ect rom the column to the middle zone of the bulb, and support between them an incandescent filament 6 of suitable form which is additionally supported by wire braces 7 also sp'ringin from the column 3, or an extension thereo Within the neck of the lamp there is formed a glass wall or dia phragm 8 made integral with the lamp bulb and spaced apart from the neck 2,.thus forming an annular chamber 9, which chamber is exhausted of all air and gas when the lamp is made. The lamp base 13 has secured thereto the dependin metallic cup-shaped aving a plurality of openings to ermlt a movement of air through the skirt and cool its interior, is positioned over the end of the neck 2, the walls of which form a part of the vacuum chamber and secured thereto, as usual, b means of cement 11 or in any other suita le way. The base contains an insulated center contact 12 and a threaded shell or side contact 13 to which the ends of the two conductors 4\and 5 are respectively soldered. These v the "incandescent filamentG which is communicated to the nitrogen within the lamp, which in turn, we will assume, circulates within the interior chamber of the lamp, causes the inner wall or diaphragm 8 of the vacuum chamber 'to become hea This heat however, is not communicate directly to the base of the lamp, but is prevented from reaching the base by the vacuum chamber 9. As the heat from the inner wall 8 of the vacuum chamber'will pass-comparatively slowto the outer wall or neck 2, and

as the heat conducted upward throughthe vgall 2 from the point 15 where. it joins the bulb1,.will be at a slow rate, it'is evident that the radiation into the atmosphere from the neck 2 will be suflicient to prevent any undue communication of heat to the lamp base with the result that the lamp can be operated without danger of destroying the.

base or causing short circuits and the evil v result-s arising therefrom.

In the form of'my invention shown in Fig. 2, the vacuum chamber is formed by providing an integral glass diaphragm 16 acrom the neck of the lamp near the point where it joins the bulb. Thus, the upper or outer part of thenormal lamp neck is converted into a sealed chamber which may be exhausted and thereby serve as a heat insulating chamber, as before described, the lamp base being secured direct to the wall of this I By. making the lamp neck substantially the same length as in the former case, it will be seenthat the heat chamber as shown.

from the bulb will have to travel the same considerable distance along the wall 2 to reach the lamp base and that, the vacuum will perform its function in the same way as, and even with greater efiiciency than, inthe tormer construction. I My nvention, however, is-not-confined, in its broad aspect, to either of the forms illustrated, since itis obvious that other modificatlons can be devised to bring about the ln-sertlon between the Wall of the lamp proper and the base, of an insulating vacuum chamber, which is the substance of my invention the scope of which is defined in the annexed claim.-

Th drawing illustrates. a cooling device for, thebulb 1, comprising tubes 16' passing having openmgs secured to said base and constituting a cooling chamber and a'vacuum chamber located between the skirt and the filament chamber.

In witness whereof I subscribe my signature in the presence of two witnesses.

' JOHN H. DALE.

Witnesses:

WALDO M. OHAPIN,

JosEPH A. BUGKLEY.

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