US1403078A - Electric-arc lamp - Google Patents

Description

J. A. HEANY.

ELECTRIC ARC LAMP.

APPLICATION FILED JUNE 11. 1917.

1,403,07 Patented Jan.10, 1922.

UNITED. STATES PATENT OFFICE.

JOHN ALLEN HEANY, OF NEW YORK, N. Y.

ELECTRIC-ARC LAMP.

To all whom it may concern:

Be it known that I, JOHN ALLEN HEANY, a citizen of the United States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Electric-Arc Lamps; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to electric arc lamps operating on very low wattages and at ordinary commercial voltages and maintaining high efliciencies even in the smaller sizes ranging as low as ten or fifteen candle power. To this end, the invention comprises a lamp, involving a container or envelope, preferably adapted for connection in the ordlnary incandescent lamp socket, and conta ning an inert gas, preferably under dlmmished pressure, and two electrodes between which the arc is maintained, connected to suitable lead wires or conductors, at least one of which electrodes is formed of a conductor of the second class, which is nonconducting when cold, but becomes conductive when highly heated, one or both of said electrodes being associated with a coil or helix of highly refractory, metallic wire, spaced from the electrodes, which serves to heat the electrodes and which constitutes a shunt or by-pass around the electrodes, which is adapted to be broken by suitable means, such as a thermostat, when the arc has been established.

In the accompanying drawings,

Fig. 1 illustrates a lamp involving the invention.

Figure 1 is an enlarged fragmentary View illustrating a modified form of the invention.

Figs. 2, 3, 4 and 5 are fragmentary views illustrating modifications of the construction and arrangement of the electrodes and the heating element.

vReferring to the drawings, 1 indicates a bulb or container of the type usually employed in incandescent filament lamps, adapted for the usual socket connection, which is exhausted of air and supplied with an inert gas, such as nitrogen, argon, or the like, preferably under diminished pressure. The bulb is provided with the usual form of glass neck 1' containing the supply leads and to which is attached a supporting wire 5 to element 4, which become Specification of Letters Patent. Patented J 1922 Application filed June 11, I

1917. Serial No. 174,102.

which is connected a lead wire 2 containing a ballast resistance 4 in the form of a coil of highly refractory metallic wire, such as tungsten, mounted upon a rod-like support 3 of refractory oxide, which wire and support become incandescent uponthe passage of current. To the lower end of the support 5 is attached by means of a clamp 5 a rodlike electrode 10, which is surrounded by a helix of highly refractory metallic wire, such as tungsten, spaced from the electrode and connected to the conducting support 5 at one end. Said electrode 10 consists of a conductor of the second class, which is nonconducting when cold, but becomes conductive and are supporting when highly heated, and may consist of a mixture of highly refractory oxides, such as oxide of zirconium, oxide of thorium and oxide of yttrium. The opposite electrode 11 may be made of the same form and materials as electrode 10, but, on the other hand, it may comprise a suitably formed body of highly refractory metal, such as tungsten or tungsten alloy, and is supported from a thermostat 12 by means of a clamp 12 carried by a stiff wire l2 fused to the thermostat which is in turn anchored at one end in the neck 1 and connected to the other lamp terminal by means of a conductor 14. When the electrode 11 corresponds to the opposite elec- L trode 10, it is surrounded by a continuation of the heating and resistance coil 6, which latter terminates in a contact 7 carried by a support 8 anchored at its upper end in the neck 1', which contact normally engages a fixed contact 13 carried by the thermostat.

It will be understood that when the electends to strike across the arc, and acts as an ionizer of the gas surroundingthe electrodes to initiate the starting of the arc.

The operation of the lamp is as follows: Current enters by way of lead 2, passes through the ballast resistance and heating incandescent, thence by way of support 5 to helix 6 surroundin the electrodes 10 and 11, thence to contact and contact 13 to thermostat 12 and by way of conductor 14 back to the other terminal of the. lamp. The highly refractory metallic helix 6 immediately incandesces and imparts its heat to the electrodes 10 and 11 and also to the surrounding gas to ionize the latter, thereby establishing the are between the ends of the electrodes 10 and 11. The heat generated acts upon thermostat 12 and causes the same to move electrode 11 away from the electrode 10 to proper arcing distance, and at the same time, breaks the circuit of the by-pass or shunt formed by the heating coil 6, at contacts 7 and 13, so that all of the current passes through the arc, which is maintained between the ends of the electrodes. The thermostat is provided so as to break the shunt and allow all the current to pass across the arc and also to bring the electrodes to the proper position to obtain the most efficiency. While the electrodes are shown spaced, yet the spacing at the time of starting the lamp is less than during the operation thereof so as to allow for quicker starting of the arc. Inasmuch as the electrodes are second-class conductors, the device is operative equally well with the electrodes in contact at the time of starting.

In the modification shown in Fig. 2, the electrodes 10 and 11 are provided with bulbous heads or terminals 10 and 11 and the heating element 6 is disposed above the terminals. The electrodes are heated until they become conductive and the arc strikes. The shunt is then broken and the current all passes through electrodes:- These electrodes are so proportioned that their resistance is sufficient to act as a ballast for the are.

In Fig. 3, the ballast is incorporated directly in the leads 2 and 14, and preferably consists of coils or filaments 4, 4" ofhighly refractory metal, such as tungsten, which not only serves as heaters, but also as incandescent lighting elements per se. In this arrangement, the electrodes and the heating coils 6 are arranged in a similar manner as illustrated in Fig. 1, and the thermostat 12' is interposed between the ballast 4" and the electrode 11.

In Fig. 4, the arrangement is similar to that illustrated in Fig. 3, except the heating coil 6 is arranged above the electrodes, as in Fig. 2.

In Fig. 5, the construction and arrangement is similar to that illustrated in Fig. 2, except for the fact that the neck 1' is extended in the form of a stem 1" to enable the supporting elements for the electrodes to be made shorter, and the operating devices of the lamp more compact.

Lamps constructed in accordance with the principles aforesaid develop a steady, brilliant are between the electrodes, emitting light of a quality and {character ICIOSQIY approximating that of sunlight and operate under an efliciency of a fraction of a watt per candle power. In the particular form of the invention in which the ballast is included in the circuit of the arc, within the lamp, the said ballast by virtue of its incandescence augments the light emitted by the are so that practically all of the current is utilized for illumination.

lVhat I claim is 1. An arc lamp comprising a container, spaced electrodes therein, at least one of which is formed of a second class conductor, a heating element of highly refractory metal adjacent to but spaced from said second class conductor electrode and normally in closed circuit between the supply leads to the lamp and serving to heat the electrode to conductivity, and means to maintain said electrodes at proper arcing distance, said means being effective to break the circuit through the heating element, when the arc has been established between said electrodes.

An arc lamp comprising a container. spaced electrodes therein, at least one of which is formed of a conductor of the second class, supply leads connected to said electrodes, a heating coil of highly refractory wire adjacent to but spaced from said electrode and normally in closed circuit be tween the supply leads to heat the electrode to conductivity, and a thermostat adapted to maintain the electrodes at proper arcing distance, said thermostat being effective to break the circuit through the heating coil when the arc has been established between said electrodes.

3. An arc lamp comprising a container, spaced electrodes therein, at least one of which is formed of a second class conductor, circuit connections for said electrodes, one of which connections includes a thermostat adapted to maintain the electrodes at proper arcing distance, and a heating coil in parallel with and adjacent to but spaced from said electrodes to heat the latter to conductivity, and contacts carried by said coil and thermostat adapted to beseparated by movement of the thermostat to break the circuit through the heating coil when the arc has been established between the electrodes.

4. An arc lamp comprising a container, spaced electrodes therein, at least one of which is formed of a second-class conductor, circuit connections for said electrodes including a thermostat adapted to regulate the distance between said electrodes, a heatin element adjacent to but spaced from said second-class electrode, one end of said heating element being connected to one lead wire and the other end to an anchor carried by the container, contacts on said heating element and thermostat to clos the circuit through said heating element when the electrodes are in their closest relation.

5. An arc lamp comprising a container, a lead wire in said container, spaced elec- .trodes in said container, at least one of which is formed of a second-class conductor, circuit connections for said electrodes including a thermostat adapted to regulate the distance'between said electrodes, a heat ing coil of highly-refractory Wire adjacent to' but spaced from said electrode, said coil being in permanent connection with said lead Wire, cooperating contacts on said coil and thermostat whereby said coil is normally in closed circuit With said lead Wire and thermostat, and means to support the free end of said coil.

In testimony whereof I aflix my signature.

JOHN-ALLEN HEANY.

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