US324334A

US324334A - Incandescent eleoteic lamps

Info

Publication number: US324334A
Authority: US
Publication date: 1885-08-11
Anticipated expiration: 1902-08-11

Description

2 Sheets-Sheet 1* (No Medel.)

. OLA. MOSES. METHOD OP'MANUFAGTURING INCANDESUBNT ELECTRIC LAMPS.

Patented Alig. 11, 1885.

INVENTOR WITNESSES W4 6L Otto .fl Moses,

By his Attorneys N. FEYERS. Phuwmhngnphir. Vlnnmgiun, D- C.

2 Sheets-Sheet 2.4 I

(No Model.)

0. A. MOSES. METHOD 015 MANUPAOTURING INGANDESGENT ELECTRIC LAMPS.

No. 324,334. Patented Aug. 11,1885.

INVENTOR Otto .fl. Moses, By hi6 Attorneys Mgwgj WITNESSES.

N. PEIERS. Phulwljlhogriplw Wfllhington, D4 C.

UNITED STATES PATENT ()FFICE.

OTTO A. MOSES, OF NEW YORK, N. Y.

METHOD OF MANUFACTURING INCANDESCENT ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 324,334, dated August 11, 1885.

Application filed October 29, 1883.

To all whom it may concern:

Be it known that I, OTTO A. MosEs, a citizen of the United States, and a resident of the city, county, and State of New York, have invented a certain,new and useful Improvement in the Method or Process of Manufacturing Incandescent Electric Lamps, of which the following is a specification.

My invention relates to that class of electric lamps in which a conducting strip, wire, or filament of carbon, hydrocarbon, or other suitable refractory substance is mounted by means of supporting conductors within a transparent air-tight globe or chamber from which the air is exhausted, and which may or may not be filled with a non-oxidizing gas or vapor. The said conducting strip, wire, or filament is rendered incandescent when traversed by an electric current, and thereby caused to emit a brilliant light.

My present invention relates, particularly, to improvements in the method or process of sealing the chamber itself after the air has been exhausted therefrom.

My improvements are illustrated in the accompanying drawings, the several figures of which represent lamps and parts of lamps as they appear during consecutive stages in the process of manufacture, as hereinafter more fully set forth.

In making my improved incandescentlamp, I first take a cylindrical glass tube, A, Fig. 1, having an external diameter of one inch and a thickness of one-sixteenth of an inch, which has a bulb, B, formed upon it by the ordinary and well-known process of glass-blowing, al-' though a bulb blown directly on the punty from the metal in the glass-makers crucible may be substituted therefor. This tube is placed in a lathe and cut off by the aid of a diamond or otherwise at a point about onefourth of an inch from the shoulder, as shown at 00 w in Fig. 1. The cut edges of the short neck thus remaining upon the bulb are next rounded by partial fusion in an oxidizing blow-pipe flame, care being taken that the internal diameter of the tube is not diminished during the operation. After the completion of this step in the process the bulb presents the appearance shown in Fig. 2. Another piece of glass tube is next taken, the original diameter of which, as shown atv O in vex or hemispherical form.

(No model.)

Fig. 3, is such as to enable it to fit closely within the tubular neck of the bulb B. This piece of tube has originally a length of about two and one-halfinches, as indicated by the dotted lines. Its extremities are then softened in the flame and drawn out in a conical form, as shown at c c in Fig. 3, leaving the middle portion, C, of its original diameter and thickness and about three-fourths of an inch in length. The middle portion, 0, of the tube is next closed at its upper end and con tracted at its lower end, as shown in Fig. 4, both ends being made approximately of a con- The diminished lower prolongation c is next cut off close to the shoulder, so as to form a short neck, 0, having an opening within it. Apiece of stout tube, D, three-sixteenths of an inch in diameter and of convenient length for handling, is

enlarged at its upper end, so that it will fit over the neck 0, as shown in Fig. 4, after which the two parts are fused together, or, as it is technically termed, soldered, in the blow-pipe flame and drawn down into the form shown in Fig. 5, leaving a narrow opening at d. A small aperture, 0", is then made in the closed top of the tube 0, through which a platinum pin or stopper, e, bent into a hook at its upper end, is dropped into the orifice d of the tube, which it closely fits, as shown in Fig. 6, although not accurately enough to be air-tight. This pin may then be slightly bent by softening and manipulating the surrounding glass, so that it will not be liable to drop out during the inversion of the bulb rendered necessary in subsequent steps in the manufacture. The tube 0 is inserted into the neck I) of the bulb B, as shown in Fig. 7, which it fits very closely, forming asliding or telescopic joint. This joint is then surrounded externally by a strong oxidizing blow pipefiame playing upon every side of it, by the action of which the neck of the bulb and the tube Gare fused into, a solid mass. The bulb B and tube 0, having thus been sealed together and brought to the condition represented in Fig. 7 are attached to a mercury or other suitable vacuum pump by means of the tubular stem D, and the air is exhausted from the interior of the bulb and tube, as perfect a vacuum as possible being obtained. The contracted neck d is then softened by surrounding it by a blowpipe flame, and is elongated and at the same time otherwise compressed around the platinum stopperE, this operation being materially assisted by the external atmospheric pressure. The tube is then cut off at the point shown by the dotted line 3 y, and the lower end of the neck D is plunged into a vessel of molten lead or other fusible metal, by which the glass is softened and annealed, while at the same time the atmospheric pressure forces the lead into any minute interstices which may exist between the platinum stopper E and the surrounding glass. A small button of lead alloyed with platinum will adhere to the lower end of the stopper at the completion of this operation, as shown in Fig. 8. Finally, the sealing of the chamber is completed by the alternate application of an oxidizing and a reducing blowpipe flame to the lower part of the stem, by I which the lead or other metal is chemically united or alloyed both with the glass and with the platinum stopper, forming, in case lead is used, a layer of silicate of lead between the lead and the glass, which passes gradually into glass on one side and lead on the other, and also alloying the platinum and lead at their surfaces of contact. In this manner the opening through which the air has been exhausted is sealed in the most effectual and permanent manner.

The lamp is now in readiness to be mounted in its supports and connected with the electric conducting-wires, which are united bysoldering or otherwise to the conductors which project from the walls of the vacuum-chamber. V

I stopperinto the neck of said chamber, softening and compressing the glass of the neck around said stopper, and plunging the neck with the stopper into molten lead or otherlike fusible metal, whereby the glass is softened and annealed and the molten metal alloyed with the stopper and cheniically united with the glass.

In testimony whereof I have hereunto subscribed my name this 16th day of October, A. D. 1883.

OTTO A. MOSES.

\Vi tn esses:

CARRIE E. DAVIDSON, Ormumcs A. TERRY.