US1384014A

US1384014A - Method and apparatus for signaling and otherwise utilizing radiant impulses

Info

Publication number: US1384014A
Application number: US211758A
Authority: US
Inventors: Reginald A Fessenden
Original assignee: Submarine Signal Co
Current assignee: Submarine Signal Co
Priority date: 1918-01-14
Filing date: 1918-01-14
Publication date: 1921-07-05
Anticipated expiration: 1938-07-05

Description

R. A. FESSENDEN. METHOD AND APPARATUS FOR SIGNALING AND OTHERWISE UTILIZING RADIANT IMPULSES.

I APPLICATION FILED JAN. I4. I918. 1,384,014. Patented July 5, 1921.

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.R. A. FESSENDEN.

METHOD AND APPARATUS ,FOR SIGNALING AND OTHERWISE UTILIZING RADIANT IMPULSES.

APPLICATION FILED IAN. I4. I9I8.

1,884,014. Patented July 5, 1921.

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' pulses from the lamp 22onstriking the re-' flector 14 are reflected toward the direction UNITED STATES PATENT OFFICE.

REGINALD A. FESSENDEN, OF BROOKLINE; MASSACHUSETTS; ASSIGi-ITOB T0 SUBMA- RINE SIGNAL COMPANY, .OF PORTLAND, MAINE, A CORPORATION OF MAINE.

METHOD AND APPARATUS FOR SIGNALING AND OTHERWISE UTILIZING RADIANT IMPULSES.

Application filed January 14, 1918.

To all whom it may concern:

Be it known that I, -REGINALD A. FEs- SENDEN, of Brookline, in the county of Norfolk and State (if Massachusetts, a citizen of the United States, have invented new and useful Improvements in Methods and Apparatus for Signaling and Otherwise Utilizing Radiant Impulses, of which the following is the specificationj My invention relates to the production and utilization of radiant impulses both in the ether and in matter. For example, light waves, heat waves, ultra-violet waves, X rays, Hertzian waves, sound waves, and the like. It relates more especially to signaling and detecting objects by radiant impulses and has for its object increased efficiency in the utilization of radiant impulses and more particularly increased efficiency insignaling and detecting bodies by means of radiant impulses.

Figures 1 to 7 show, partly diagrammatically, apparatus adapted for carrying out my invention.

In Fig. 1, 14 is a reflector for radiant impulses constructed in any suitable way so as to reflect, in the direction from which they came, radiant impulses striking it, no matter, within certain limits, how the reflector may be tilted.

For example, in Fig. 4 the radiant imof the lamp, as shown in the dotted lines.

I accomplish this by arranging three

reflecting surfaces

11, 12, and 13 so that each is at right anglesto the other two; From this construction I obtain the result that no matter how the reflector is tilted, so long as the radiant impulses enter the solid angle formed by the three reflecting surfaces 11,

12, and 13, the light or other radiant impulse is reflected back toward the source.

The optical properties of such geometrical arrangement of plane reflecting surfaces are easily established from long known optlcal laws but so far as can be ascertained have never been practically constructed or utilized, and in the absence of any naine for this arrangement'of three reflecting plane surfaces at right angles to each other it has Specification of Letters Patent.

Patented July 5, 1921.

Serial No. 211,758.

been called, as a matter of convenience, the reflector.

The linear dimensions of these reflectin surfaces are--.preferably large multiples of thedwave length of the radiant impulses use These

reflectingsurfaces

11, 12, 13 may consist of three mirrors, as shown in front view in 1 and in side view-in Fig. 2. For signaling purposes they are preferably mounted as shown with a diagonal of one reflecting surface 11 horizontal, though the exact arrangement is usually a matter of no importance.

The reflector 14, formed of the three reflecting

surfaces

11', 12, 13 is conveniently attached to a rod 15. To this rod 15 is at? tached a shutter 16, as shown, operated in any convenient mannerfor example, by a key or aphotographic bulb release or, as

shown, by the string 45. 17 is a mirror attached to the sleeve 18 so that it can be slid up and down the rod 15. When the mirror 17 is at an angle of approximately 45, it and the upper reflecting surface 11 form a trench perisco e so that an eye placed, as shown, at 46, i 2, will see by reflection objects to the rig t as shown by the dotted lines. The shutter 16 is omitted in Fig. 2 in order to show more clearly the use of the apparatus as a trench periscope for signal- 1ng.

Fig. 3 shows another form of reflector in which instead of using three plane mirrors a tetrahedron consisting of the corner of a cube of transparent material such as glass is used, 11, 12, and 13 being the portions of the sides of the cubes which meet to ether at one corner andithese sides of the on e being silvered while the fourth side of the tetrahedron, facing the observer, as .shown in Fig. 3, ,is left unsilvered. The silver coating is covered with some protecting material, such as cement, rubber, or metal.

The corner where the three sides 11, 12,

For example, it is more compact and the sides beinm once ground at the right an le the reflecting surfaces always maintain tiieir true relation. Also there is some advantage when non-chromatic light is used in that the color of the reflected light gives some indication of the way in which the reflector is held and somewhat widens the field.

The object of grinding off the corner 20 as shown in Fig. 3 and polishing it, or in the case of the three mirror type drilling the hole 20, as shown in Fig. 4, is so that the observer by placing his eye in the position 46 may observe the signaling light 22.

Fig. 4 shows an arrangement of apparatus suitable for communicating between the first line trenches and the rear trenches or between the advance and the first line trenches.

During the present year, 1917, the official reports of the operations on the west front are to the effect that the best method of signaling so far found for the advance is the signaling lamp, substantially a heliograph using artificial instead of solar illumination. The objections to this, as stated in the official report, are that when provided with suflicient storage battery to last in case the ad- Vance is cut off by barrage it is too heavy; also that the man carrying it cannot carry his rifle or anything else; also that there is often'considerable difliculty in the advance signaler and rear signaler getting in touch with each. other, since both projecting lamps have to be alined simultaneously.

The present invention overcomes these difficulties and has other advantages.

The method of using is shown inFig. 4. Here 21 is a shutter, 22 a source of light, 23 a reflector, v24: a telescope. These are used by the naler to the rear, or in the case of advance} y the signaler in the trenches. 14 is the reflector, 16 a shutter, 20 a hole bored at the corner of the reflecting planes, and 46' is the eye of the forward signaler. The reflector is all that is carried by the forward signaler who, in an advance, may be four or five miles in front of the trenches where the rear observer is. 3

The operation is as follows: The front signaler goes forward equipped with the reflector 14, and, as this weighs less than eight ounces, carrying his full equipment of rifle, etc. Suppose when he is a couple of miles in advance it is desired to communicate with him. To do this the rear signaler swings his projlecting lamp 22, 23 over the terrain, keeping iis eye at the telescope 24:. As soon as the beam of the projecting lamp strikes the reflector 14 the rear observer sees a flashand knows that the projecting beam .is in the right direction. At the same time the forward signaler with his eye at the point 46' sees the flash from the projecting lamp. The rear signaler then by moving the shutter- 21 signals the call letter of the forward signaler sev ral times and then leaves the shutter 21%4 {the open position. The forward si naleil ttiien moves the shutter 16 andcuts thebeam of light reflected back to 24: and thus "gnals to the rear observer and communication is thus established.

In signaling at night time where it is not desired that the beam of the projecting lamp 22, 23 should be seen by the enemy, in place of a tungsten lamp 22 a source of ultraviolet radiation, such as a quartz mercury tube, may be used with a screen cutting off all visible radiation, as is well known in the art, and the round corner 20 or the opposite face of the tetrahedron may be coated with a, florescent substance, such as sulfate of quinin, and also the object glass of the telescope 24.

This method has the following advantages for signaling during an advance:

(1) The whole apparatus carried by the advance signaler weighs less than eight ounces and consequently he can carry his usual equipment.

(2) The apparatus cannot get out of order.

(3) It can be operated isolated from all supplies for any length of time as it does not require fresh batteries, lamps, etc., to be brought up from the rear through territory exposed to shell fire.

(4:) The signaling range may be much greater than with projection lamps, as the only light source is operated from a fixed vance signaler.

(6) As the direction of reflection back is not influenced by the wabbling of the refector, the forward signaler does not have to stop in order to receive messages from the rear signaler, and in fact by facing the reflector toward the-rear and using the periscope mirror as shown in Figs. 1 and 2, he ma receive and transmit messages While wa king or even while running forward.

(7) The forward signaler can operate his apparatus while protected in the trench by sticking the pointed end 19 of the bar 15, Fig. 1, in the ground so that only the reflector, a few inches square, projects above the trench.

(8) Itis easily manufactured and inexpensive.

For the above reasons, and others, it is extremely well adapted for signaling during an advance and for other work, such as signaling between an artillery station and. an. 30

aeroplane and where ultra-violet light or infra-red light is used it has the additional advantage over wireless and other forms of signaling that the fact that signaling is going on is not disclosed to the enemy.

Applicant has discovered that infra-red radiation is especially advantageous in that it is not affected by transmission through fog or smoke to anything like the same extent to which ultra-violet radiation is affected.

Fig. 5 shows the application of the inven-- tion to marine work-in the ease shown to a buoy marking the position of a channel. Here 25 is the buoy having a number of these reflecting

prisms

14, 14, 14, 14 of any kind of colored glass'desired arranged as a crown on the top of the buoy.

A ship desiring to pick up the channel, on coming within three or four miles of the sup-posed entrance to the channel, swings its projector around the horizon. Immediately the projector beam is pointing in the direction of the buoy the man standing beside the projector sees the answering flash, since no matter how the buoy 25 is rocking or tilting on the water the beam is always reflected toward the source, 11. 6., toward the projector.

This method has the following advantages:

(1) The buoy may be picked up over a greater distance than a. light buoy because the source of light 2'. 6., the arc lamp pro-' jector, of the ship is a much more powerful source than the source of light installed on the light buoy.

(2) The buoy cannot be mistaken for shore lights or any light carrying object.

(3) In time of war channels may be left marked with this type of buoy because the only way in which an enemys shi could ick up the buoy would be by using t is proector, in which case the enemys ship would be immediately observed. a

(4) A ship icking up a buoy in this way does not disc ose the position of the buoy to any other ship in the vicinity as the reflected beam is sent back directly to the ship carryin the projector. 1

(5) arge and expensive buoys are not necessary as the apparatus will work just as well when installed on an inexpensive spar buoy. v

(6) The cost of maintenance is practically nothing and there is nothing to get out of order as the prism crown can be protected by an iron grating.

Fig. 6 shows the apparatus applied to wireless telegraphy. In this case only one set of sending apparatus is necessary, as shown in the upper part of Fig. 6.

Here 26, 27 are the radiating conductors, preferably dimensioned so as to radiate Hertzian waves of a few centimeters wave length. 28 is an oscillating audion, or pliotron,,pro-

ducing waves of a few centimeters wave length. 34 is a switch for signaling and 2%) a. source of electric power for exciting the audion 28. y The receiving apparatus is shown in the lower part of Fig. 6, where 30, 31 are the receiving conductors, 32 a wireless receiving apparatus of any suitable form, and 33 a double head telephone receiver.

14 is the reflector and 16 a "shutter, in the present case preferably made of metal and slanted at an angle so that its plane is not perpendicular to the dotted lines showing the path of the Hertzian waves.

The operation is similar to that of the optical apparatus shown in Fig. 4.

Fig. 7 shows the apparatus arranged to operate with sound impulses of very short wave length.

The transmitting apparatus is shown in the upper part of Fig. 7 and consists of a source of high frequency oscillations 35, which may be a pliotron generator or, as shown, a high frequency dynamo giving say 50,000 cycles per second. of the type described in applicants U. S. Patent 706,737, issued August 12. 1902.

36 is a transmitter to be used when the apparatus is used for telephoning. 37 is a. key, kept closed when telephoning and operated when the apparatus is used for telegrapliing. 39 is the source of sound, which may be an oscillator of the type shown in applicants U. S. Patent 1,167,366, issued January 4, 1916, which has been found very suitable for producing such high frequency mechanical vibrations, or a condenser of the type shown in applicants U. S. Patent 1,182,843, issued 1V ay 9, 1916, Fig. 5, with the additional improvement, 2'. e. the local battery 38, the addition of this local battery having been found to increase the efiiciency of the apparatus as a generator. 40 is a diaphragm, which may be one plate of the condenser 29 or may be a separate plate of metal or other suitable material. The receiving apparatus is shown at the bottom of Fig. 7, where 42 is any suitable receiving apparatus, for example the oscillator above referred to, and 41 being either a plate of the condenser or a separate diaphragm. 44 is the receiver, which may be of any suitable typecapable of receiving high frequency electrical vibrations, and 43 is a local battery. 14 is the reflector and 16 is a shutter, as above.

The method of operation is as described with reference to Fig. 4.

These ultra-audible sound vibrations, called by the writer anacysms, have a number of advantages in that they can be projected as a well defined beam of sound and can be used for secret sending and operated by the heterodyne or similar apparatus.

Means for signaling by radiant impulses specification decomprising 'a tetrahedron having three adjoining faces at right angles to each other and a, surface in proximity to said tetrahedron whereby the incidence of radiant energy on sald tetrahedron may be determined.

REGINALD A; FESSENDEN.