US1504603A - Signal light - Google Patents

Description

| w. CHU BB SIGNAL LIGHT Filed Jan. 30 1920 WITNESSES: INVENTOR Patented Aug 12, 1924.

' UNITED srA ras PATNT OFFICE. 7

LEWIS WARRINGTON GHUBIB, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SIGNAL LIGHT.

Application filed January so, 1920. Serial No. 355,153.

a resident of Edgewood Park, in the county 6 of Allegheny and State of Pennsylvania,

have invented a new and useful Imp-rovement in Signal Lights, of which the followin is a specification.

T Ty invention relates to signalling means and particularly to electrically-operated signal lights and has for its obyect to provide electrical means for producing intense flashes of light for signaling purposes.

In signalling between ships or between stations on land by means of periodically interrupted beams of light, it is highly desirable to obtain the maximum intensity of the beam of light. A. high intensity of the beam of light not only increases the working range of the signal but it also permits of an appreciable reduction in the duration of the. beam of light while still obtaining the desired results. This is for the reason that the efiect, upon the eye of an observer, of a beam of light of relatively high intensity maintained for a relatively brief interval of time is equal to, or greater than, that of a beam of light of lesser intensity but ma ntained over a considerably longer time 1nterval. This fact becomes of great importance when it is desired to transmit messages by means of flashes of light of different-lengths arranged according to one o1 the codes used for such purposes.

In certain of the heavy-current-arc searchlights now in use for signalling purposes, 1t is necessary to use water cooling of the electrodes, and the light of the continuously- .burning arc is periodically interrupted by means of a suitable shutter mechanism. T have found that, in signal work, the light is used less than 50% of the time and that great operative improvements may be obtained b extinguishing the are between successive ashes of light and dispensing with the shutter mechanism. I prefer also to produce, during the working period of the light, a succession of heavy-current pulses so close together that the light appears substantially continuous because of the retinal persistance of the eye of theobserver.

In practicing my invention, 1 provide a pair of spaced electrodes, which may be located in a reflector, and connect them to a source of stored electrical energy, which is, in turn, connected to a source of relatively high direct-current electromotive force. The secondary terminals of a spark coil are connected to the spaced electrodes, a spark ga being included in the circuit. A source of electromotive force is provided for the primary circuit of the spark coil and suitable mechanism is provided for periodically closing and interrupting the primary circuit. This mechanism may comprise a a hand-operated key or a motor-driven commutator, the former being provided where it is desired to send messages from one station to another and the latter being provided where the device is to be used in a lighthouse.

' Referring to the single figure of the drawing, conductors l and 2 represent a supply circuit of relatively high direct-current electromotive force, and 3 an ad 'ustable rheostat connected in circuit with t e conductor 2. A condenser 4, having a relatively high capacitance, is connected across the circuit, which comprises two spaced electrodes 5 and 6 suitably mounted in a reflctor 7, and two reactors 8, 8, which are connected between the electrodes and th condenser. The electrodes may be either of metal or of carbon and are so located that the gap therebetween is relatively small. The reactors 8, 8 may consist of relatively small numbers of turns of conductors having air cores.

A spark coil 9 has one of the terminals of its secondary coil connected to the electrode 6 and the other terminal is connected to one terminal of a spark gap 10, the other terminal of which is connected to the electrode 5. A suitable sourceof electrical energy 11, here shown as a battery, is connected to the primary winding of the spark coil through a circuit-closing device 12, here shown as a biased key, and an interrupter 13 may also be provided.

The operation of the device is as follows: the electrodes 5 and 6 and the electrodes of the spark gap 10 having been adjusted to obtain the proper operative distance therebetween (it being noted that the distance between the electrodes 5 and 6 is relatively small), the supply circuit, which may have is connected to the conductors 1 and 2 through a suitable switch (not shown), and

the rheostat 3 is so adjusted as to reduce the current, which the supply circuit may cause to traverse the electro es and 6, to a relatively small value. As soon as the supply circuit has been connected, the condenser is charged, the charging current flowing through the rheostat 3. If now the key 12 is so 'moved as to energize the primary winding of the spark coil 9, current will traverse the secondary winding and sparks Wlll occur between the terminals of the electrodes 5 and 6 and across the spark ga 10. If the interrupter 13 is omitted, a smgle dischar e is obtained, under the above conditlons, w 1le,

if the interrupter is used, a succession of dischar es is obtained; The discharge across t e airgap between the electrodes 5 and 6 acts as a pilot spark for the discharge of the condenser 4 across this gap. As the capacitance of the condenser 4 is relatively lar e, the air gap between the electrodes 5' an 6 is relatively small and the inductance of the two reactors 8, 8 is also relatively small, the current traversing the electrodes 5 and 6 is relatively large and results in a flash of light of very high intensity. As the initial current traverses the reactors 8, 8, a small amount of energy is stored in them, and the voltage of the condenser is thereby reduced to a point below the value required to maintain the arc between the electrodes 5 and 6. The condensers: is, however, charged again as soon as the arc current ceases, and the condenser is then again ready to discharge across the gap between the electrodes 5 and 6. If the key 12 is operated to close the circuit through the primary winding of the spark coil 9 for only a small interval of time, a relatively smalLnumber of intense flashes of light will be produced by the interrupter 13, while, if the circuit be closed for a greater length of time, a proportionately arger number of such flashes of light will be produced. In this way, it is possible to produce, visually, the effect of telegraphic dots and dashes and thus to transmit messages. a

The reactors 8-8 are of use not only to assist in causing the main current to tend to oscillate through the electrodes 5 and 6 and extinguish the are but also operate to prevent the current furnished by the secondary winding of the spark coil from traversing the condenser 4.

The spark gap 10 is eflective to prevent part of the current from the condenser 4 traversing the secondary winding of the spark coil and also helps to prevent the current in the secondary winding of the spark coil traversing the condenser 4, by producing a steep-wave-front dischar The apparatus embodying m invention thus provides a means of pr ucing very intense flashes of light for varying time intervals by means of which messages or warning signalsmfhy be transmitted.

he simpl' cation of the signal-light mechanism and the elimination of the shutter mechanism permits of the application of the principles of remote control to a signal light constructed and operated in accordance with my invention. The si al light may thus be mounted at the top of a mast an be operated from a deck or a cabin of the ship.

If desired or necessary, flame-arc electrodes may be=used instead of ordinary arc electrodes to increase the intensity of the light obtained by the use of the device embod ing my invention.

arious modifications may be made in the circuit embodying my invention without departing from the s irit and scope thereof, and I desire that on y such limitations shall be placed thereon as are imposed by the prior art or are specifically set forth in the appended claims.

I c aim as my invention:

1. In a signal light, the combination with two spaced electrodes, a source of directcurrent electrical energy connected thereto, and a condenser connected to said source of energy and to said electrodes, of electric means connected to said electrodes for breaking down the resistance of said spaced electrodes and thereby causin said condenser to dischar e across sai electrodes, the resistance of t e circuit containin the electrodes and the source of current ing 'suflicient to prevent the flow of current therethrough after the condenser has become discharged.

2. In a signal light, the combination with a pair of spaced electrodes, a source of electrical energy and a condenser connected to said electrodes and to said source of energy, of electric means for reducing the resistance between said electrodes, and means for permitting the source of energy to fully char e said condenser and for permitting the flow of only a relatively small amount of current from said source of energy through said electrodes insuflicient to maintain an arc across the electrodes when said condenser discharges through said electrodes after the resistance therebetween has been reduced by said electric means.

3. In a signal li ht, the combination with a pair of s aced e ectrodes, a source of electromotive orce connected to said electrodes, and a condenser connected to said source of electromotive force and said electrodes, of a spark coil having its seconds. coil operatlvely connected to said elect es, means for I energizing said spark coil; a spark gap consaid source of electromotive force to an neeted between said secondarycoil and one amount insufiicient to maintain an are of said electrodes, means for preventing the across the electrodes.

current traversing said electrodes, sparkv gag In testimony whereof, I have hereunto 5 and secondary coil from traversing sai subscribed my name this 26th day of J anu- ,condenser, and means for reducing the curary, 1920.

'ren't value delivered to said electrodes by LEWIS WARRINGTON CHUBB.

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