US398774A

US398774A - Incandescent electric lamp

Info

Publication number: US398774A
Authority: US
Publication date: 1889-02-26
Anticipated expiration: 1906-02-26

Description

(No Model.)

T. A. EDISON.

INGANDESGENT ELECTRIC LAMP. No. 398,774. Patented Feb. 26, 1889 0 3. F/lyl 1 11313.

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UNITED STATES PATENT OFFICE.

THOMAS A. EDISON, OE MENLO PARK, NElV JERSEY.

INCANDESCENT ELECTRIC LAMP.

SIECIFICATION forming part of Letters Patent No. 398,774, dated February 26, 1889.

Application filed May 14, 1883. Serial No. 94,891. (No model.)

In Fig. 3 the plate I) is inserted into the glass of the stem B, as before explained.

In Fig. 2 a short glass tube, F, is placed over one end of the filament. This would be placed over the filament before the latter is attached to the lcading-in wires.

In Fig. 4 the disk of insulating material G is placed over the middle of the straight filament, being thus interposed between the terminals thereof.

In my Patent No. 242,896 is shown a glass arm of small diameter extending up between the sides of the carbon loop to support the same. It is evident that this would not accomplish the object of the present invention, as the small glass arm would admit of the formation of the are around said arm.

lia-t I claim is 1. In an incandescing electric lamp, the combination ,with the incandescin g conductor, of solid insulating material interposed between its terminals and adapted to prevent the formation of an are between said termi- To aZZ whom it may concern.-

Be it known that I, THOMAS A. EDISON, of Menlo Park, in the county of Middlescx and State of New Jersey, have invented a new and useful Improvement in Incandescent Electric Lamps, (Case No. 562,) of which the following is a specification.

The object of this invention is to prevent the formation of an are between the terminals of the conductor within the globe of an incandescing electric lamp. I accomplish this by interposing between the terminals of the conductor an insulating body, preferably of a transparent material, like mica or glass. This of course increases the resistance of the space between the terminals and so prevents the formation of an arc across such space.

In applying the invention to a lamp in which an arched or looped carbon filament is used I preferably place a thin plate of glass or mica between the ends of the loop, rising to a su'fiicient height and supported by a metallic or other arm rising from the middle of the inner stem or wire support of the lamp benals, substantially as set forth. tween the leading-in wires; or the edge of the 2. In an incandescing electric lamp, the plate may be inserted in the stem, the glass combination, with the arched or looped conbeing softened and split to admit it; or I ductor, of an insulating-plate interposed bemay have one end of the filament inclosed tween the terminals of said conductor and by a glass tube resting upon the glass below. adapted to prevent the formation of an arc \Vhen a straight carbon is employed, a between said terminals, substantially as set glass or mica disk having an aperture in its forth. center maybe placed around the middle of 23. In an incandescing electric lamp, the the carbon, so that insulatirnl is interposed combination, with the arched or looped conbet ween its terminals. ductor and the glass stem or wire support, of

The invention is illustrated in the accoman insulating-plate interposed between the pany drawings, in which" terminals of said conductor and supported l igure 1 is a view of an incandescing elec from said wire support and adapted to pretric lamp embodying the preferred form of vent the formation of an arc between said my invention; Fig. 2, a view of a portion of terminals, substantially as set forth. the lamp with the glass tube inclosing the 4. In an incandescing electric lamp, the lower portion of one side of the filament; combination, with the arched or looped con- Fig. 3, a view showing the insulating-plate ductor and the glass stem or wire support, of inserted in the glass of the stem, and Fig. 4 an insulating-plate having its edge inserted a view showing the invcntiim applied to a in the glass of said support and extending up st raight carbon lamp. 3 between the terminals of said conductor and .i represents theinclosing-globeof the lamp, l adapted to prevent the formation of an arc and ll isthe inner stem sealed therein. The between the terminals, substantially as set leading-in wires 1. 2 are sealed in the glass forth. and support the tlmible carbon filament C, This specification signed and witnessed this which is securcsl to said wires by electroplat- 8th day of May, 1883.

'L F' I Tnos. A. EDISON.

Rclerring to l ig. l, l) is a plate oi glass or mica interposed between the sides of the filament U and supported by an arm, E, rising from the glass of the stem B.

\Vitnesscs:

WM. H. MEAnowcRoE'r, H. W. SEEL'Y.