US2058734A

US2058734A - Lamp

Info

Publication number: US2058734A
Application number: US588749A
Authority: US
Inventors: Sperti George
Original assignee: SPERTI LAMP CORP
Current assignee: SPERTI LAMP Corp
Priority date: 1932-01-25
Filing date: 1932-01-25
Publication date: 1936-10-27
Anticipated expiration: 1953-10-27

Description

LAMP

Filed Jan. 25, 1932 Patented on. 27, 1936 UNITED STATES.-

a George Sperti, Govington, Ky aasignor to Sperti Lamp Corporation, New York, N. Y., a corporation oi. Delaware Application Januaryflfi, 1932, Serial No. 588,749

6 Claims. (01. ire-1) This invention relates to lamps of the type combining a source of visible radiation such as an incandescent filament with an arc constituting a source of visible and ultra-violet radiation and 5 particularly to an arc element for use in such or other lamps or for use as an arc lamp alone.

, In prior applications of George Sperti, forexample, application Serial. No. 572,394, filed October 31, 1931, there are disclosed lamps of the k above type wherein the source of visible radiation is constituted by an incandescent filament of tungsten or the likeand wherein the are is established between electrodes in an atmosphere of ionized gas or vapor'such as mercury. 'The resultant spectrum of such a lamp is that of the incandescent filament having superimposed thereon thev spectrum of the arc, so that the radiation from the lamp closely resembles natural sunlight in character and quality. The are radiation reinforces the radiation from the incandescent filament particularly in the short ultra-violet which is of recognized therapeutic value, and means are provided for preventing the emission from the lamp of objectionable radiations shorter than about 28m) to 2900 Angstrom units.

Lamps .of this type are designed iorgeneral illumination so as to provide artificial light equivalent or nearly equivalent to natural sunlight and to this end they should be capable of use in place or the ordinary incandescent lamp at normallighting. voltages and currents. The lampdescribed in the aforesaid application embodies both an outer and an inner bulb, the incandescent filament being disposed in the outer bulb and the arc in the inner bulb so that these two sources may be operated independently as regards conditions such as gas and vapor pressure, etc. Hence the arc element is complete in itself and M may, if desired, be used without the incandescent filament seen are lamp. The design of the lamp described above,.however, is such that it may be. used to replace the ordinary incandescent lamp for all purposes without the use of exterm nal controlling and starting devices, ballasts, etc. The lamp disclosed in the aforesaid application is particularly adapted for use with alternating currents, although also operable with direct ourrent, and the object of the present invention is to provide a novel lamp of the type described and more particularly a novel are element for use alone or in such a. lamp which is particularly adapted for use with direct current, although it may also be used with alternating current.

5 One embodiment oi the invention has been acteristics.

illustrated in the accompanying drawing,- but it is to be expressly understood that said drawing is for purposes of illustration only and is not to be construed asa definition of the limits of.

the invention, reference being had to the appended claims for this purpose.v

In the drawing, Fig. l is a perspective view of a lamp embody-. ing the invention; and

Fig.2 is a sectional view of a part oi the lamp 10 shown in Fig. 1.

- Referring new toy the drawing, the lamp in the form shown comprises abulb l of any desired type, size and shape which is mounted in the usual or anysuitable base 2. In the form 15 shown, the bulb l is constituted of material which transmits ultra-violet light of the desired wave lengths, that is, ultra-violet radiationslonger than 2800 to 2900-Angstrorn units. Thebulb may, if desired, be of material which is opaque m; to shorter radiations, but in the form shown it is unnecessary that this bulb have filtering char Sealed in the neck of the bulb'is a, stem or standard 3 constituting the usual means for introducing conductors t and 5 into the bulb as and forsupporting the various elements within the bulb. An incandescent filament t, or tungsten or other suitable material, is supported in v the bulb l by means of wires l and t that are fused in the stem 3, the wire I constituting a. no.

connection from one end of the filament tothe conductor t. Filament 6 may also be supported by a plurality of wires 9 carried by a bead it formed on an inner bulb H which is in turn supported from the stem 3 by means or a-supat porting. band it and supports it and M1. In

. most cases, it is desirable that the bulb ll have i or standard it and preferably contains a-quantity of mercury or other ionizable gas or vapor which produces the desired radiations. Enclosed within the bulb H is a pair of cold electrodes be-- to tween which the arc is established. In order to render the lamp self starting, at least one of these electrodes is associated with an ionizing element which is adapted to be heated so as to assist in ionizing the gas or vapor within the bulb and in starting the arc. Referring now to Fig. 2: one

- of the electrodes comprises a grid or coil 21 carried by a supporting'wire 26, said coil surrounding and being electrically connected to a heated ionizing element which in the form shown comprises a tube [6, preferablyvclosed at one 'end, supported in the inner bulb H in any suitable manner as by means of a supporting band I1 and.

a supporting wire l8 that is fused in the stem IS. The tube l6 may be of metal such as nickel or tungsten, or of conductive oxides such as zirconium oxide, etc. lreferably the tube is coated either partially or entirely with one or more oxides which have relatively high electronic emission when heated, such as oxides of barium, strontium, thorium, etc., this coating being indicated diagrammatically at Is. Where the tube i6 is made of zirconium oxide and the like, one or more of these active oxides may be mixed with the zirconium oxide.

The other electrode is constituted by a substantially cylindrical element surrounding the electrode 21 and supported in any suitable manner as by means of wires 2i and 22 that are fused in the standard I5. In the iorm shown, said element 2!! comprises a wire screen, but .it may be a cylindrical plate or coil.

A potential difierence is established between the

electrodes

21 and 20 in any suitable manner, preferably by connecting in parallel with said electrodes a circuit which includes means for heating the ionizing element l6. As shown, one end of the'filament 6 is connected to the wire 8, and the aforesaid parallel circuit is connected between the wire 8 and theconductor 5. To this end a wire 23 is connected to the supporting wire 8 and also to the support 2|. connected at one end to the electrode support 2| and at the other end to a heating filament 25 enclosed within the ionizing element IS. The other end of filament 25 is connected both to the tube support It and to the supporting wire 26 which carries coil electrode 21 surrounding the tube l6. Filament 25 may be insulated from the, tube IS in any suitable manner as by coating said filament with a suitable cement? When'current is supplied to the lamp, it first fiows'in series through the conductor 4, supporting wire 1, filament 6, supporting wire 8, wire 23, resistance 24, filament 25, wire 26 and conductor 5. It will be noted that the

electrodes

20 and 21 are. connected across or in parallel with the resistance 24 and the filament 25 so that the potential drop therethrough is impressed across said electrodes to establish and maintain the arc therebetween. The are may strike at once between the

electrodes

20 and 21, in which case the tube is will practically remain unheated because the resistance 25, 24 is greater than the resistance of the parallel arc path. If the arc fails tostrike, the filament 25 heats the tube I6 and also supplies heat to the atmosphere of gas or vapor within the bulb l I. The heating of tube I 6 drives 01! any ions of gas or vapor which were adsorbed by said tube and also heats the oxide coating l3 so that the electronic emission there- A resistance 24 is rapid disintegration by this cooling oiI of the filament 25 and, also by the protection against electronic bombardment afiorded by the grid electrode 21. I

The electrode 21 should be negative with respect to the electrode 20' in order for the arc to operate properly in case direct current is used. This can be insured by proper wiring of the sockets in which the lamp is' used, or if desired,

included in the wiring connections to the socket so that if the arc does not start the polarities of the socket terminals may be reversed. Referring to Figure 1, a suitable socket is shown at 28, current being supplied to the socket by

wires

28 and 30 which lead to the poles 3i and 32 of a reversing switch 33 of any suitable type. In case the lamp does not start when the switch 33 is closed, said switch is reversed in order to reverse the polarity of the

electrodes

21 and 20. It will be understood that the reversing switch is illus trated in diagrammatic form only; for example, it may comprise either a rotary switch or a knife switch and may have any suitable structural relationship with the smket 28. i

(It will be understood that the invention is not limited to the form described and illustrated in.

the drawing. Thus the bulb I may have any desired shape and size and may be mounted in any desired type of base. Similarly the bulb ll may have any desired size and shape and may be supported within the lamp in any suitable manner The ionizing element l6 may be of different materials as described above and may be of other forms than tubular. The grid electrodes 21 may also comprise a screen or the like within the lamp may also be varied. For example, the resistance'24 may be constituted by a portion of the filament 8 by suitable connections which will be apparent to those skilled in the art, and in some cases the resistances of the filament 25 will be suflicient without the use of additional resistances such as resistance 24. may be made in the form, details of construction and arrangement of the parts without departing from the spirit of the invention and reference is therefore to be had to the appended claimsfor a definition of the limits oi the invention.

What is claimed is:

1. An electric arc lamp comprising three concentric tubular elements, the inner element comprising an oxide coated member having high electronic emission when heated and the intermediate and outer elements comprising cold electrodes, a connection between the inner and intermediate elements placing said elements at substantially the same potentialwith respect to the circuit of the lamp, 9. singlepair of lamp terminals, connections from said terminals to the in-' termediate and outer elements, and resistance means connected between said terminals and including a heating fllamerit within said inner element and in parallel with said intermediat and outer elements.

- 2. An electric arclamp comprising a tubular ionizing element coated with an oxide having high electronic emission when heated, a single pairof lamp terminals, a heating filament connected between-said terminals and disposed with-. in said ionizing element, a cold electrode adjacent a reversing switch of any suitable type may be Other changesinstead of a coil. The electrical connections said'ionizing element and connected therewith, a

, second cold electrode spaced from said first electrode and ionizing element, and connections from .saidelectrodes to said terminals.

3. An electric lamp comprising a bulb, an incandescent filament therein, an inner bulb, a tubular ionizing element coated with an electron emissive material disposed within said inner bulb,

a cold electrode associated with said ionizing element, a second cold electrode in said inner bulb spaced from said first electrode, resistance means including a heating filament and connected in series with said incandescent filament across the terminals of the lamp, said heating filament being disposed within said tubular ionizing element, and connections from said electrodes to said series circuit at points of difierent potential. v

4. An electric arc lamp comprising a bulb, a pair of cold electrodes in said bulb, a single pair of terminals for said lamp, connections between said terminals and said electrodes, an electronemi'ssive ionizing element in said bulb, and resistsmce means including a. heating filament for said ionizing element connected between said electrodes in parallel with the arc path therebetw'een.

5. An electric arc lamp comprising a bulb, .a

pair of concentric-cold electrodes in said bulb, a single pair of terminals for said lamp, connections between said terminals and said electrodes, on electron-emissive ionizing element adjacent to ,and electrically connected with one of said electrodes, and resistance means including a heating filament for said ionizing element connected between said electrodes in parallel with the arc path therebetween. ,1

6. An electric lamp comprising-an outer bulb, an incandescent filament in said outer bulb, an inner bulb, a pair oi cold electrodes in said inner bulb, a single pair of terminals for said lamp, said incandescent filament and electrodes being connected in series across said terminals, an electron-emissive ionizing element in said inner bulb, and resistance means including a heating filament for said ionizing element connected between said electrodes in parallel with the arc path therebetween.

' GEORGE SPERTI.