US1355598A

US1355598A - Apparatus for directive signaling

Info

Publication number: US1355598A
Application number: US136627A
Authority: US
Inventors: Reginald A Fessenden
Original assignee: Submarine Signal Co
Current assignee: Submarine Signal Co
Priority date: 1917-08-16
Filing date: 1917-08-16
Publication date: 1920-10-12
Anticipated expiration: 1937-10-12
Also published as: FR500068A

Description

n. A. FES'SENDEN.

APPARATUS FOR DIRECTIVE SIGNALING.

' APPLICATION man AUG. 16, 1911.-

1,s55,59s. Patenm 00A. 12, 1 20.

EEG E SIGRZQL CQTEPAilY, 0F PORTLAND,

HALE) A. FESS'ENDEB, OF BROOKLIW, MA-

.assresron. to sustain 'rron TEIMR'E.

eas es;

T 0 all whom .2)? may concern:

Be it known that I, REGINALD DEN, and State of Massachusetts, a cltlzen of the United States, have invented a new and useful Improvement in Apparatus for Dlrec tive Signaling, of which the followlng 1s a specification.

My invention. relates to the transmission and receipt of energy and more particularly to signaling and still more part cularly to directional signaling, especially the location of submarines and submarine signaling stations and also of aeroplanes.

The object of myinvention is to improve the eiiiciency of the sending and receiving energy and more especially to improve the efiiciency'of signaling and still more to improve the eiliciency of apparatus and methods for locating submarine slgnalmg stations and submarines. It may be used on shipboard or otherwise.

The figure accompanying this specification illustrates, partly diagrammat1cally,ap-

A. FEssEN paratus adapted for carrying out my invention.

In the figure, of the destroyer type and 30, 31 and 32 are the compartments of the forepeak or 011 tanks of the torpedo destroyer, though they may be fluid containers otherwise located, according to circumstances.

11 and 12 are sound receiving devices of any suitable kind; for example, microphones or stethoscopes, or electro-magnetlc receivers and preferably oscillators of the kind described in. United States Patent No. 1,167,366. I shall hereinafter refer to these, generally speaking, as sound detectors These oscillators are shown as located on board ship and are placed in any suitable position with reference to each other, either side by side, or, as shown, back to back in the same tank or adjacent fluid containing tanks, and preferably have their faces perpendicular to the skin of the ship. As shown, they are separated by the sound insulating screen l3, 14, of any kind, being attached to each other and to it by the bolts 15, 16, which may be insulated therefrom by soft rubber or lead in a known way.

Both oscillators and sound screen are mounted on a pivot 29 and can be rotated by any suitable means, as for example, by

the handle 17.

Specification of Letteraratent.

of Brookline, in the county of Norfolk.

83 is a vessel for example' are adjustable inductances.

lF'e/tentediict. 312, i922.

Application filed August 16, 1917." t'lcrial l lo, 1393122.

' The sound screen 13,14, may be con- *structed and shaped in any suitable way to produce-the desired result; for example, at

the end 14: the sound screen is shown in curved shape so as to shield to a greater extent than at'thefend 13.

I prefer so to shape the sound screen 13,

' 14 that a sound coming from 'a given angle and striking the oscillators will be heard with the same relative intensities and phases as a sound coming from the same angle and striking the head of a human being.

The shape of the sound screen to accomplish this is best determined by experiment,- the shape being varied until a person listening in on telephone receivers attached to the oscillators will obtain'the same change in relative sound-intensities in the two receivers when the oscillators are turned to a certain angle as he obtains when he turnshis head through thesame angle.

An important point to note. is that when l the oscillators are used in a difl'e'rent medlum from air, for example in water, the distance of the oscillators apart should preferably bear the same relation to the velocity of sound in such medium, for example water, as the usual' distance; apart of the two ears of a human-body bearsv to the velocityof sound in air. For example, if the distance between the cars is 8 inches and the velocity of sound in air is 1100 feet per second, then it the'oscillators are inimersedin water, in which'the velocity of sound is 4400 feet per second, the oscillators should preferably be placed a little less than 13 feet apart. If the oscillators are placed farther apart, as ,for example, 10 feet, still further changes are obtained and the sound screen must be extended still farther in order to obtain the desired efiect on turning the oscillators around on their pivot 29.

18, 19, 20,21are leads from the oscillators to the indicators shown as telephone receivers 26, 27, which with the other apparatus may be located upon the. bridge or other convenient place and are connected by the head band 28 but are not electrically con nected to each other.

-33 and 34 are switches for opening or ciosing the lead circuits as desired.

22, '23 are adjustable capacities, and 2d, 25

'lhese capacitiesand inductances have the function, in

addition to their other functions, that by changing their relative values the phase of the sounds reaching the receivers 26, 27, can be altered without turning the oscillators on their pivot, or, it the oscillators are turned on their pivot, the change of phase may be increased or decreased.

For example, if a sound is received on the port bow, the oscillators may be either turned by means of the handle 17 until the sound appears to come from a point perpendicular to and in front of the line joining the centers of the diaphragms of the two oscillators, the sound then being equally loud to both ears of the observer, and the anglethrough: which the handle ll"v is being moved may be measured and the exact direction of the sound be thus determined. Or the oscillators-may be left stationary and the condensers 22, 23, or inductances 24:, 25, or both, adjusted until the sound appears dead ahead and the readings of the sou densers and inductances taken and in this way the exact direction determined. Or both oscillators and condensers and inductances may be left stationary and the vessel turned until the sound appears to come in dead ahead and the bow is pointed in the direction of the source of sound,

The tanks 30, 31, 32 are preferably filled either with water or oil, and when the oil is used up, it is preferably replaced with water.

The insertion of the oscillators in fluid filled tanks, for example, forepeak tanks, or, as shown, in oil tanks, has the great advantage that, as applicant has discovered, it enables the sound to be received nearly as well dead ahead as abeam.

For exam le, with the installation placed on the S. S. eoereaiuw the distance at which it was possible to send 'and receive dead ahead was 31-1; miles as against 36 miles abeam. With the installation placed on the U. S. destroyer Ag Zwia the working dis tance dead ahead was 843% of that abeam.

l have discovered that it is possible to still further increase the range dead ahead or dead astern by making the skin of the ship or the wall of the tanks or the chamber containing the sound receiver so that the index of sound refraction of the skin of the ship or the wall of the tanks relative to water is unity.

For example, the velocity of sound in water is approximately 4400v feet per second, while the velocity of sound in steel is approximately ll',000 feet per second. Consequently, sounds striking the skin of the ship at a small angle are totally reflected and do not enter the ship and aii ect the oscillators. l have found, however, that by loadinn" x" th ship so that the index or a 1,855,&Qt3

attach, lumps or disks or plates of lead or other suitable material, such as tungsten, to the inside of the skin of the ship, or to use material such as zinc or tin or tin alloyed with lead, or to use a plate having holes punched in it, the holes being tilled with lead or brass. Other arrangements may suggest themselves, but whatever the arrangement used, it should be such as to make the index of refraction of the skin of the ship or the wall of the tanks relative to water-equal to unity, and if weights are used, such as disks of lead,'they should be close together, i. 6., the distance between any two adjacent ones should be approximately equal to less than a quarter wave length of the sound which is to be received.

This method is also of value as a method of eliminating high pitched sounds which it is not desired to receive, as sounds whose quarter wave length is less than the distance between the weights may be retracted while sounds of longer wave length will be trans mitted.

Other arrangements of: apparatus to ac complish this result andbe within the scope of my invention will occur to those skilled in the art,

What I claim is:

1. The combination of a fluid container,

two sound detectors located in the fluid in said fluid container, a sound screen located between said sound detectors, and two indicaters, each connected to one of the sound detectors, said sound screen being" shaped as described whereby it will produce a sound shadow with relation to said detectors similar to that produced by the human head with relation to the ears.

2. The combination of a fluid container, two sound detectors located in the fluid in said fluid container, a sound screen located between said sound detectors, and two indicators, each connected to one of the sound detectors, said sound screen being proportioned with relation to said detectors ap-. proximately as the human head is to the location of the ears.

3. The combination of a fluid container, two sound detectors located in the fluid in said fluid container, and two indicators, each connected to one of the sound detectors, the connections between said detectors and indicators com arising inductances and capacities adaptec to vary the current phase generated by the detectors and received by the -etector located avingits substantially the same as that of the medium outside the tank through which the slgnals are sent and received.

5. A tank and a sound detector located the medium through which the desired sig-- nals are transmitted and received whereby the index of refraction of said wall will be made substantially the same as water.

' 6. A tank and a sound detector located therein, a wall ofsaid tank being loaded with weights 'separated'from each other by a distance approximately less than one quarter wave length of the desired sound wave in the medium through which the desired signals are transmitted and received whereby the index of refraction will be increased.

7. A tank and a sound signaling device located therein, a wall of said tank being loaded with weights separated from each other, by a distance approximately less than one quarter wave length of the desired sound wave,in the medium through which the desired signals are transmitted and received whereby the index of refraction of said wall will be made substantially the same as water.

8. A tank and a sound signaling device located therein, a wall of said tank being loaded with weights separated from each other by a distance approximately less than one quarter wave length of the desired sound wave in the medium through which the desired signals are transmitted and received whereby the index of refraction will be increased.

9. The combination of two electric circuits, two electrically-operating sound detectors connected to said electric circuits and adapted to cause currents of varying in- 10. The combination of two electric circuits, two electrically-operating sound detectors connected to said electric circuits and adapted to cause currents of varying intensity to flow in said electric circuits upon the receipt of sound waves, indicating means connected to said electric circuits adapted to produce an indication on the receipt of sounds, and means located in said electric circuits, adapted to vary the phase of the varying currents caused to flow by the rethe other, and adapted to determine the diceived sounds in each of said circuits rela 65 'tively to the other.

' 11. The combination of two electric circuits, two electrically-operating sound detectors connected to said electric circuits and adapted to cause currents of varying intensity to flow in said electric circuits upon the receipt of sound waves, indicating means connected to said electric circuits adapted to produce an' indication on the receipt of sounds, and means, comprisin inductances and capacities located in sai electric circuits, adapted to vary the phase of the varying currents caused to flow by the received sounds in each of said circuits relatively to rection from which the sounds are received.

12. A submarine signaling apparatus comprising a liquid container, two submarine signaling mechanisms located in the liquid in said container, and means for varying the angle between the line joining the center ,of said two submarine signaling mechanisms and a second line drawn through the center of said first line and terminating at opposite sides of said container.

13. A submarine signaling apparatus comprising a container, a submarine signaling mechanism located within said container, one wall of said container being adjacent to the medium through which the signals are sent and received, said wall of said container having its index of refraction of sound relative to water substantially the same as that of the medium outside the container whereby signals are transmitted and received in directions substantially parallel'to the plane of said wall of said container with increased efficiency and loudness.

14. A li uid container, a submarine signaling mec anism located therein, a wall of said container having weights attached thereto, the distance between said weights being less than the quarter wave length of the signals in the liquid, whereby the index of refraction of'sound relative to water of said wall'may be made to have a desired value.

15. A container, a submarine signaling mechanism located therein, a wall of said container having localized inertia whereby its index of refraction of sound relative to water maybe made to have any desired value.

16. A container, a submarine signaling mechanism located therein, a wall of said container having localized inertia whereby its index of refraction of sound relative to water is made substantially the same as that of the medium outside the container throu h which the sounds are sent and recelve REGINALD A. FESSENDEN,