US660816A - Producing high vacuums. - Google Patents

Description

He. swans. Patented 0st. 30, mos. .1. w, SEBWELL.

PRUDUClNG H552! VACUUMS.

(Application ill-2d A'xg. a1, 1899.)

(Ho Model.)

\Mtnesses. J nventor.

UNITED STATES/ ATENT O FFI-CE,

JOHN W. HOWELL, OF NEWARK, NEW JERSEY, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEW YORK.

PRODUClNG HIG H VACUUMS,

srncmoa'non forming part of has Patent No. 660,816, dated October so, 1900.

Application 11106 August 31, 1899- I Serial No. 729,076- (No specimens.)

To all whom it'mayjconcerm' Be it known that I, JOHN W. HOWELL, a citi- 'zen of the United States, residing at Newark, county of Essex, State of New Jersey, have invented certain new and useful Im provements in Producing High Vacuums, (Case ing a High vacuum ata lowercost than by. any method heretoforeproposedwith'which' No. 1,376,) of which the following is a speci-' fication.

My invention relates to the production of high vacuums, and is particularly adapted for service in connection with the exhaustion of incandescentelectric lamps. By the methods commonly employed in the manufacture of incandescent lamps,'gases,including air and hydrocarbon gases, are trapped or occluded "in the filament and itsjoints and moisture is deposited on the walls-of the bulb, the-last traces of which are exceedingly difficult to ,remove and in the case of high-voltage lamps require for satisfactory life of the filamenta long-continued exhaustion by'the pump.

A good vacuum may be established by mechanicalpumps, the design ofwhich is fa.-

miliar to those skilled in the art, but at the expense of considerable time-for exhaustion. Methods have been designed for promoting rapidity of exhaustion and the. removal of the last traces of deleterious gases, so as produce a. satisfactory vacuum, by introducing within the bulb neutral or inert gases and then again continuing the exhaustion; but difliculty is experienced-in providing an inert gas which is sufficiently free from impurities to afford a satisfactory result. Other methods have been proposed for acting chemically upon the residual gases occluded i'hthe fila-f ment and its joints by vaporizing. solids or liquids capable of combining with them and removing the products of the reaction My process afiords a imeaus' fo'r' establish- ,I am familiar. 1

I carry out my invention by producing a preliminary exhaustion by the aid of apump, for which I prefer to employ a good type ofand then continuing the exhaustion with the filament brought to incandescence. I then admit to the bulb a determinate'volume of phosph'in .or phosphoreted hydrogen gas at ordinary atmospheric temperatures, which acts not only mechanically as a vehicle for assisting the exhaustion of the residual gases byawashing-out action, but establishes a sul'tant cheapening of the'cost of the lamp.

This decrease in theexpe'nse is an incident principally of the gaseous treatment by which a gang or group of lamps may be simultane ously subjected to the action of the gas, and I an attendant may therefore manage several independent machines or'exhausting devices.

No particularorganizatien of apparatus is required to carry out my invention, except provisions for pumping off the air or gases and for introducing the phosphin. It will,

. however,'greatly facilitate an increased 'output per'operator to follow the usual plan of v connecting with each pump an exhaustiom tube'haviug a plurality of air-tight sockets or openings to receive the stems of a group of lamps. The arrangement of'such apparatus and t-he construction of the lamp are so known form of lamp-bulb inwhicha tubular ;stem 1 isleft after the pillar carrying thefilament has been sealed into the-neck of the lamp and by which the exhausting processes are conducted, after which the.bulb 2 is sealed ofi near its junction with the stem. and the lampis ready for the market.

I In practicing my process the stem 1 isconnected by an elastic joint in the usual manner with a pump, for. which I prefer to employ a mechanical pump, and agroup of eight or more lamps are similarly connected to the roe same pump. A rough exhaustion is then made and the usual tests for defects in the is then raised to a high temperature by pass- "quantityof phosphoreted hydrogen is then lamp structure or filament-joints made by connecting with-J an induction-coil or other source of high-tension current. The filament ing a current through it and allowed to burn a short time to allow the pump to exhaust the occluded gases. A definite graduated admitted to the group of lamps by means of phosphoreted hydrogen and the products of its reaction: upon the residual gases will have beenwil-hdrawn. The phosphoreted hydrogen acts as a menstruu m or vehicle to carry off the residual gases by diffusing throughout the bulb andmixing'with them and also reacts chemically upon such occluded gases as are capable of reacting with it.

I prefer to generate the phosphoreted hydrogen by heating phosphorus in a-solution of caustic potash, though other methods, such as heating it with milk of lime or mixing phosphid of calcium with water, may be employed. In any of these processes the'phosphoreted hydrogen (PH is not chemically pure, but carries with it more or less vapor of the liquid phosphid of hydrogen, (P ll which has a great affinity for certain gases, and especially oxygen at reduced pressures. I believe the hydrocarbons present are decomposed by the action, of the phosphoreted hydrogen, which takes on an additional atom or atoms of hydrogen at the expense of the hydrocarbon gases in the bulb, and therebyfacilitates an -almost complete exhaustion of the residual gases, The heating of the lamp both internally and externally duringthe operation drives elf any film of moisture which may be deposited upon the inner wall of the globe or other parts, which is removed with the gas by the pump.

What I claim as new, and desire to secure by Letters Patent of the United States, ta-

1. The process of producing high vacuums, consisting in exhausting air or other gas from the inclosnre, then admitting phosphoreted hydrogen and again exhausting the iltclosure. 2. The process of producing a high vacuum in an incandescent lamp, consisting in first exhausting the air and other gases from thebulb, then admitting phosphoreted hydro-' gen, then again exhausting the bulb.

3. The process of producing a high vacuum in an incandescent lamp, consisting in exhausting the air and other gases from the bulb in which thefilament is mounted, then admitting a-compound gaseous at ordinary atmospheric temperatures having an afiinity for the residual gases in the bulb, then exhausting the bulb. 7' 4. The process of producinga high vacuum in an incandescent lamp, consisting in ex-.

hausting the air and other gases from the.

bulb, heating the lamp, admitting a determinate quantity of phosphoreted hydrogen, I

then exhausting and sealing oti the lamp.

. 5. The processof prodncingahigh vacuum in an incandescent lamp, consisting in first exhausting the bulb, then heating the filament and walls of the lanip, then admitting phosphoreted hydrogen to the bulb, then again exhausting.

In witness whereof I havehereunto setmy hand this 23d day of August, 1899.

JOHN W. HO WELL.

Witnesses:

A. R. DENMAN, V IRVING T. TYLER.

Images