US856483A - Automatic gas-feed for vacuum-tube lamps. - Google Patents

Description

, I mlm flirzm 777cm r BY No. 856,483. PATENTED JUNE 11, 1907.

D. MOP. MOORE.

AUTOMATIC GAS FEED FOR VACUUM TUBE LAMPS. APPLIOATION FILED MAY a. 1906.

' wmv Esses; INVENTOR ATTORNEYS UNITED STATES PATENT OFFICE.

DANIEL McFARLAN MOORE, OF NEWARK, NEW JERSEY, ASSIGN OR TO MOORE ELECTRICAL 00., OF NEW YORK, N. Y, A CORPORATION OF NEW YORK.

AUTOMATIC GAS-FEED FOR VAClJUNl-TUBE LAMPS.

Specification of Letters Patent.

Patented June 11, 1907.

Application filed May 8,1906. Serial No. 315,729.

To (LN/111770727, it may concern:

Be it known that I, DANIEL MCFARLAN Moons, a citizen of the United States, and a resident of Newark, in the county of Essex and State of New Jersey, with post-office address 52 Laurence street, have invented certain new and useful Improvements in Automatic Gas-Feeds for Vacuum-TubeLamps, of which the following is a specification.

My invention relates to that class of electric lamps known as vacuum tube lamps wherein the source of light is a gas or vapor excited to luminosity by electric energy of any proper form or kind.

The object of my invention is to maintain a constant tension or density of the gas or vapor within said lamp so as to maintain a constant luminosity.

Briefly stated, my invention consists essentially in supplying gas to the tube by devices automatically responsive to changes or variations in the intensity of the light so as to maintain a practically constant tension or density of the gas or vapor.

For simplicity, I show my invention as ap-' plied to a vacuum tube lamp having, internal electrodes, although, as will be obvious, the nature of the electrodes and the manner of furnishing the electric-energy to the gaseous contents may be varied indefinitely without departing from my invention.

My invention consists also in the specific combinations of devices comprising amongothers the combination of a vacuum tube, a selenium cell, means for feeding gas to the tube from a body of gas'of greater tension than t t within the same and an actuating or con rolling magnet connected to ,a circuit of the selenium cell.

' Referring to the accompanying drawings, Figure 1 is a general side elevation and partia-l section of an apparatus embodying my inventlon. Flg. 2 shows a modification 1n the manner of making the changes of resistance of a selenium cell effective to operate a valve. Fig. 3 shows a further modification.

1 is a vacuum tube lamp having the usual or any proper terminal or electrodes 2 by which electric energy is caused to circulate through the gaseous contents of said tube.

3 is a selenium cell of any desired character exposed to the light of the tube and pref- -sources of light. .as a variable resistance in the electric circult erably inclosed in a box or casing 4 to protect it against the influenceof outside Sald selemum cell operates containing or having connected to it an electromagnet or other means responsive to variations of electric current, said magnet being in turn used to cont-rel the operation of the devices which supply the proper gas or vapor to the vacuum tube'l. The gas supplied may be obtained from any source.

I prefer to feed gas into the tube from a body of gas of greater tension than that within the tube, the feed being regulated or controlled through the action of a suitable valve. The body of gas-in said tube may be derived from the atmosphere, a gas generator as described and claimed in my application for patent filed April 16th, 1906,

S. N. 311,815 or a gas converter through When a valve is employed, the same may be of the kind described in my prior application for patent filed Aug. 21st, 1905 and in a division of said application filed April 16th, 1906, or may be any other construction of valve.

4 is a valve chamber of glass to which gas is supplied through a pipe 5 and in which is located the tip of a plug 6 of some porous material like electric light carbon, which plug.

fits in the end of a tube 7 through which the gas is fed to the tube. Surrounding the plug 6 is a body of mercury 8, which surrounds the tapered plug. By changing the level of the mercury to expose or conceal the pointed tip of the plug or more or less of said tip, the flow of gas from said chamber 4 through the porous material of the plug to the feedpipe 7 may be varied. Normally the tipis more or less concealed beneath the level of the liquid and little or no gas can flow, but when the level falls, the tip is exposed or is more exposed and gas may fiow in minute amount. The changes of level in the liquid by which the valve action is produced may be brought IuO about by any means responsive to changes in the resistance of the selenium cell. As a type of such devices, I show an electromagnet 9 included in the circuit of any source of electric energy 10' and selenium cell 3., The movable core of said magnet is properly attached to a plunger or displacer 1 1 which 7 works in the body of mercury surrounding plug 8. Other means might be employed for bringing about the change in the level of the liquid when the resistance in the selenium cell 3 changes.

In the operation of this apparatus, the valve may be so adjusted by adjusting the position of the magnet coils that no portion of the tip will be exposed above the mercury, and hence no gas will flow, so long as the density or tension of the gas in tube 1 is at the normal so as to give a light of the normal intensity The adjustment-might, however, be such that under the conditions supposed, a very little of the tip would be exposed. The

density or tension of gas in the tubebeing of such a degree that a decrease of tension will have the eflect of lowering the resistance of the gas to the passage of the current, any decrease of such density below normal will permit more current to flow andhence increase the intensity of the light. This variation in the intensity of the light will, by acting directly upon the selenium cell, produce a change of electric resistance therein, lowering such resistance and thereby increasing the power of the electromagnet 9 which latter causes the valve to open and feed gas or more gas to'the tube 1. As soon as the gas tension or density has thus been brought back to normal, the light will fall in intensity to normal and the resistance of the selenium cell will increase owing to the less action of. the light thereof so that the magnet 9 will decrease in power and the plunger will be permitted to drop back in order to close or partially close the valve. This act1on is repeated upon any increase of gas tension or density in the tube 1 requiring an additional supply of gas to bring the tension back to normal. q The changes of resistance due to the changes in the intensity of the light may be made effective, obviously, through other devices responsive to change in current flow, thus for instance, the circuit of the selenium cell may, as shown inFig. 2, be provided with an electric heater typified as a coil 12 which is in shunt to the selenium cell so that a decrease of resistance itself will bring, about a decrease of current flow in the heater. The heater typified as a mere resistance coil may be applied to a chamber 13 containing a body of mercury connecting through a pipe 14 with the chamber containing the mercury seal for the valve. Obviously, the expansion of the mercury, due to the action of the holder, will maintain the mercury at such height as fto the level of the mercury around the tip of the 4 plug to drop slightly and 'feed gas to the tube 1,

Preferably, the relative bulk of the mercury in the valve chamber to that in the chamber 13 is small in order to secure a delicate action of the device when the tension of the gas in the tube 1 has been restored to normal and the intensity of the light brought back to normal the selenium cell will, through increase of its resistance, force more current into theheater and cause an expansion of the mercury, so as to close or more completely close the valve and cut off the supply of gas.

Many other variations in the apparatus will suggest themselves to electricians as suitable for causing gas to be supplied to the tube when the current in a circuit is modified or changed through changes of action of a selenium cell exposed to the light of the tube.

A selenium cell is shown as typical of all devices adapted to respond to variations in the intensity of light in a manner to bring about the physical action that may be utilized electrically or mechanically to vary the supply of gas to the tube.

The selenium cell may be used as a generator of energy when exposed to the light of the tube and the source 10 be removed from the circuit thereof. This modification is shown in Fig. 3. In this form the cell furnishes current influctuating amount to an electromagnet 20, and the electromagnet 9 is in a circuit connected to the armature and contact point of electromagnet 20 as shown. Normally, the circuit of the magnet 9 is opened but when, through increase of light in the tube, the cell generates more energy, magnet 20 closes the circuit of the coils for electromagnet 9 and the latter acts to open the valve. Suitable adjustment of the valve in all cases may be secured by adjusting the position of the coils of the electromagnet 9 1n Figs. 1 and 2 or by adjusting the number of turns in the heater coil or by any other suitable means.

What I claim as my iiivention is:

1. The method of maintaining a gas tension or density of a vacuum tube lamp at normal by supplying gas thereto in accordance with variations in the intensity of the light of said tube. v

2. The method of maintaining the luminous condition of a vacuum tube lamp at its normal by regulating the admission of gas to said lamp through variations in the intensity of the light of said lamp.

3. The combination of a vacuum tube lamp, a selenium cell exposed to the light ot said lamp and means responsive to variations in the resistance of said cell for supplying gas to the lamp.

4. The combination of a vacuum tube lamp, a selenium cell exposed to the light of said lam and means responsive to variations in t e resistance of saidcell for feeding gas to the lam from a body of gas of greater densitv than t at in the lamp:

5. The combination of a vacuum tube -lam a selenium cell exposed to the action of t 10 light of said la1n a valve through which gas may be fed to t e lamp, and means responsive to variations in the resistance of 'responsive to variations in the intensity of the light. Signed atNeW York in the county of New York and State of New York this 5th day of May A. D. 1906. l

DANIEL MCFARLAN MOORE.

Witnesses:

C. F. TISCHNER, Jr., LILLIAN BLQND.

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