US1899587A - Incandescent electric lamp - Google Patents

Description

Feb. 28, 1933. J QUESSEQUE 1,899,587

INCANDESCENT ELECTRIC LQAMP Filed Sepi}. 24, 1931 [1W5 N TUE. VJL'AN GUESSEQUL',

Ms A? TURKEY Patented Feb. 28, 1933 UNITED STATES PATENT OFFICE JEAN QUESSEQUE, OF ISSY-LES-MOULINEAUX, FRANCE, ASSIGNOR TO GENERAL ELEC:

TRIC COMPANY, A; CORPORATION OF NEW YORK momnnscnn'r' mac'rmo LAMP Application filed September 24, 1981, Serial 110. {564,888, and in France October 31, 1930.

My invention relates to incandescent electric lamps and more particularly to such lamps provided with a gas filling.

The object of my invention is to provide a simple and effective means of preventing the blackening of the bulbs of such lamps.

After a lamp has been burning one thousand hours, blackening of the bulb, with a resulting loss of luminous efiiciency, becomes noticeable. Said blackening is due to the disintegration of the filament, whereby tungsten particles, torn from the hot filament, are carried by the convection currents to the walls of the bulb, where they are deposited. Due

to the loss of luminous efliciency, it may be more economical to replace a lamp thus blackened with a new one before the filament is broken. Blackening of the bulb becomes an increasingly greater problem in the higher power lamps.

The appearance of a lamp is also impaired.

by the blackening of the bulb, which is an especially important objection in lamps which are used for decorative purposes.

Electric and magnetic systems have been roposed to obviate the blackening of the bulb, but they are relatively complicated and difficult to utilizein practice. Another method consists of placing a powder in the bulb ing the bulb. This method, of course, requires a special manipulation "of the bulb by the user.

According to my invention, blackening of the bulb is prevented by the interposition, in

the path of the convection currents, of av shown in 0 with which the walls are cleaned by revolv In the drawing, Fig. 1 is an elevation of an incandescent electric lamp showing the convection currents therein; Figs. 2, 3 and 4 showvariations in the arrangement of the screens within the bulb; and Figs. 5 and 6 show different forms of screens.

Referring to Fig. 1, the lamp comprises a 'bulb 10'and base 11. A filament 12 is connected to inner lead wires 13 sealed into'a stem press 14. An arbor 15 is sealed to the stem press 14. The arrows show the direction of the convection currents inside of the bulb. These currents rise vertically from the filament to the neck of the bulb, then follow the walls of the bulb down to the bottom thereof. Referring to Fig. 2, the screen 16 comprises a conically wound spiral of wire consisting of a metal such as tungsten, molybdenum, nickel or iron, which is sup orted by wires 17 sealed into an arbor 18. 11 their u ward travel, the particles breaking oil the filament, come in contact with the screen 16 to which they adhere, thereby preventing their deposit upon the walls of the bulb. Referring to Fig.v 3, a spiral of wire 19, forming the screen, is simpliy wound upon an arbor 20 of a lamp.

Re errin to Fig. 4, a screen 21, of the form igs. 5 or 6, is shown supported on wires 22 sealed into an arbor 23. A piece of mica 24 deflects the upward rising current of gas so as to protect the base of the bulb from the intense heat.

As shown in 'Fig. 5, the screens may take the form of a wire cloth consisting of a metal such as tungsten, molybdenum, nickel or iron. Another form, shown in Fig. 6, comprises a perforated foil which may consist of a metal, such as hereinbefore mentioned, or of a nonmetallic substance such as glass or mica.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a gas-filled electric lamp, the combination of a light source comprising a refractory metal adapted to be heated and a screen member comprising a hollow body having a 90 multiplicity of openin in the sides thereof located above said lig t source when said lamp is in use and extending longitudinally of said lamp.

2. In a gas-filled electric lamp, the combination of a light source comprising a filament distributed about the longitudinal axis of said lam and a screen member comprising a ollow body having a multiplicity of openings in the sides thereof located above said light source when said lamp is in use and extending longitudinall of said lamp and having its axis substantlally coinciding with the said longitudinal axis of the said lamp.

In witness whereof, I have hereunto set my hand.

- JEAN QUESSEQUE,

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