US1552349A - Electric-light apparatus - Google Patents

Description

Sept. 1, 1925. 1,552,349

W. DA. RYAN ELECTRIC LIGHT APPARATUS Filed Feb. 20, 1925 ig- 23.

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particular pattern.

Patented Sept. 1, 1925.

UNlTED STATES PATENT OFFICE.

WALTER DA. RYAN, 0'1? SGHENEGTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC CGMPANY, A QURPOBATION OF NEW YORK.

ELECTRIG-LIGHT APPARATUS.

Application filed February 20, 1923.

To all whom it may concern Be it known that I, WALTER DA. RYAN, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Electric- Light Apparatus, of which the following is a specification.

My i1 Vention relates to an improvement in electric light apparatus of the type in which an arc lamp having a plurality of anodes is used.

Arc lamps are usually constructed with a single positive electrode and a corresponding negative or cathode electrode. In some cases a pair of anode electrodes are used but in either case a single crater is maintained and when are lamps of this type are used in a Searchlight a single beam is produced. hen a search-light of this type is used in an effort to locate an object at a distance such as a flying machine, it is often the case that the machine can dodge the beam, particularly if the beam is moved to describe a Among the objects of my invention is to provide an arc lamp in a search light which will produce a series of beams which will make it more diiiicult for an object with such an airplane to success fully carry out its dodging operation. It is one of the objects of the invention to provide an arc lamp with a series of anode electrodes on one side of the are. It is another object of my invention to provide means for causing the arc to pass from one of the anode electrodes to the other in succession, to provide means for causing the shifting to take place at such a rate as to create the effect on the eye as though a series of beams were maintained in operation at the same time to produce an elongated beam which may be rotated in order that an object when once located by the beam may be followed by simply rotating the beam, if the object happens to be moving to one side of the center of the beam. It is also an object of my invention to produce such a beam in order that when an elongated object such as a war ship is located, the beam may be rotated until the major axis of the beam extends parallel or approximately parallel to the longitudinal axis of the object. I also contemplate providing other details of improvement for increasing Serial No. 620,309.

the efliciency of a device of the above character.

A means for accomplishing the above and other useful ends are hereinafter set forth and claimed.

Referring to the accompanying drawing, Fig. 1 shows the arc lamp in perspective; Fig. 2 is an end view of the lamp; Fig. 3 is a detail of the cathode electrode; Fig. 4 shows the lamp associated with a parabolic reflector and so mounted that the anode terminals and the opposite cathode are in the proximity of the focus of the reflector; and Fig. 5 is a diagrammatic drawing of the circuits of the lamp and of the commutator.

Referring more in detail to the drawing, the frame A of the lamp may be of any suitable form. As indicated it is provided with a plate 2 and a plate 3 which plates are held together by the rods 4. The cathode electrode 5 on one side of the arc passes through the plate A and is held insulated from the plate by a washer 6 of any suitable insulating material. This cathode may be fed by any suitable feeding mechanism. The anode electrodes 7 8 and 9 are insulated from one another as indicated in Figs. 2 and 5 and are secured within the rectangular holder 10. These anodes may be rigidly secured with respect to the frame as indicated in the drawing and the frame as a whole moved under the control of a feed mechanism as is commonly done, or the electrodes may be made movable with respect to the frame and may be fed independently of any movement of the frame. The are lamp as a unit may be secured to the reflector as indicated in Fig. 4. The feeding of the cathode may take place behind the reflector. Referring to Fig. 5, the conductors 11 and 12 are connected with any suitable source of power such as a dynamo or battery. Conductor 12 is connected with the cathode 5 on one side of the arc. On the other hand, the conductor 11 is connected with a brush 13 which latter is in electric engagement with a ring 14. This ring is in electric connection with the seg ment 15 of the commutator. Associated with the commutator are three other brushes 16, 17 and 18. Each of these brushes is connected as indicated in Fig. 5 with one .Of the anode electrodes on the same side of the arc. The commutator may be driven by any suitable mechanism so that the segment 15 is caused to engage the brushes 16, 17 and 18 one at a time. The result is that the anodes are thrown in circuit with the mains 11 and 12 one at a time and, therefore, the arc is caused to travel from one anode to another on one side of the arc while the other side of the arc rests perma ncntly on the cathode 5. With this arrangement it will be seen that I provide three arcs, one between the cathode 5 and the anode 7, another with the anode 8 and a third with the anode 9, Inasn' uch as these arcs shift with respect to the focus of the reflector, each arc causes a separate d distinct beam to be projected from the rei'l ctor B. However, only one beam is actually in existence at a time but the commu tator is caused to rotate such a speed as to produce the alternation of the beams at such a rate as to leave an impression on the eye as though they all persisted at the same time. lVith this arrangement, therefore, the search-light will in eliect cover a much larger region and consequently the operation of locating an object can be carried out much more effectively and much more rapidly by minimizing the possibility of the object dodging the searcher.

hat 1 claim as new and eesire to secure by Letters Patent of the United States, is,-

In a searchlight, an arc lamp having a series of anode electrodes a common cathode and a distributor, and a pair of conducting leads for connecting the lamp with a source of current, one of said leads being connected to the cathode, said distributor being interposed between the other lead and the anodes whereby said anodes may be connected one at a time with the last mentioned lead and an are formed between the cathode and the anodes in succession.

In witness whereof I have hereunto set my hand this 19th day of February, 1923.

lVALTER DA. RYAN.

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