US2769975A

US2769975A - Electromagnetic object-tracking-anddestroying method and system

Info

Publication number: US2769975A
Application number: US625162A
Authority: US
Inventors: Rines Robert Harvey
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-10-29
Filing date: 1945-10-29
Publication date: 1956-11-06
Anticipated expiration: 1973-11-06

Description

2,769,9 75 ING R. H. RINES ELECTROMAGNETIC OBJECT-TRACKING -AND-DESTROY Nov. 6, 1 956 y K METHOD AND SYSTEM Filed Oct. 29, 1945 5 Sheets-Sheet 1 www Nov. 6, 1956 2 769,975

YR. H. RINES x ELECTROMAGNETIC OBJECT-(TRACKING-AND-DESTROYING METHOD AND SYSTEM Filed Oct. 29, 1945 5 Sheets-Sheet 2 w82 l mi #Fa g I oFMuLT/v/B/wrof? M e @Z5/My Nov. 6, 1956 R. H. RINEs 2,769,975

ELECTROMAGNETIC OBJECT-TRACKING-AND-DESTROYING METHOD AND SYSTEM Filed Oct. 29, 1945 5 Sheets-Sheet 3 OUTPUT OF V/.DEO AMF @MSHA/74H75? F76. 6.)

r u W o W c m y M E D 2,769,975 ING Nov. 6, 1956 R. H. RINES ELECTROMAGNETIC OBJECT-TRACKING-AND-DESTROY METHOD AND SYSTEM 5 Sheets-Sheet 4 Filed Oct. 29, 1945 ll--I Nov. 6, 1956 R. H. RlNEs 2,769,975

ELECTROMAGNETIC 0BJECT-TRACKING-AND-DESTROYING METHOD AND SYSTEM Filed Oct. 29, 1945 5 Sheets-Sheet 5 V/JEO OU TPU T Ml/L 7'/ V/ERKITOR GAT/N6 OUTPUT United Stats ELECTROMAGNETIC OBJECT-TRACKING-AND- DESTROYING METHQD AND SYSTEM The present invention relates to electric methods and systems, and more particularly to methods and systems for controlling the explosion of shells or other projectile explosives.

An object of the invention is to provide a new and improved radio-locator=andtracking system.

A further object is to provide a novel radio-controlled tiring system.

A further object is to provide for controlling the burst of a shell or other projectile explosive from a point distant from the position of the projectile in motion.

.According to present-day techniques, after a projectile, such as a shell or a rocket, has been red from a projector toward a target object, such as an airplane, the time of its explosion is controlled at the projectile itself. The explosion may, for example, be under the control of a time fuse, a powder-train fuse, a radio-transmitting-and-receving mechanism, or a photocell fuse in the projectile. The control is such as to assure the explosion of the projectile at the moment of its approach toward the airplane object. If a time fuse or a powder fuse be employed, the target airplane is detected, its line of ight is plotted in order to make possible the prediction of its future position, and the time mechanism -in the projectile fuse is set accordingly before tiring. In the case of a radio fuse r a photocell fuse, the explosion of the projectile is effected by the mere fact of its proximity to the target object, and no further control from the ground is necessary. All these prior-art methods are subject to the disadvantage that the projectile may explode at a time or a place where it will not harm the enemy and may, in fact, damage a friend. At the very least, a premature or a too-late or otherwise useless projectile explosion may serve to inform an enemy aircraft that it is under fire. In the case of proximity fuses, furthermore, tiring at low-flying aircraft in low quadrants of elevation, for example, will often cause premature explosion because of the proximity of the ground to the shell.

Another object of the present invention, therefore, is to explodevonly those projectiles that are sufiiciently near to the airplane or other enemy object to produce lethal effects.

Still another object is to prevent the explosion of projectiles that have traveled beyond, or have otherwise missed, their mark.

A further object still is to provide a fuse mechanism for exploding the projectile accurateiy, at any desired time during its ighL'from the point of its tiring, or from any other position remote from the projectile.

Other and further objects will be explained hereinafter, and will be particularly pointed out in the appended claims.

'The invention wiil now be more fully explained in connection with the accompanying drawings, in which Fig. l is a diagrammatic view of circuits and apparatus arranged and constructed f according to a preferred embodiment thereof; Fig. 2 is a diagrammatic view showing a radioreceiving fuse provided' in the projectile, and operable in arent Fatented Nov. f8, T356 conjunction with the circuits of Fig. 1 to cause the projectile to explode; Figs. 3 to 13, inclusive, represent idealized voltage-wave forms illustrating the operation of the various components of the disclosed circuits, Fig. 3 illustrating the transmitted radio-frequency pulses, Fig. 4 the output of the attenuator-rectier, Fig. 5 the output of the radio receiver, Fig. 6 the output of the video stages, Fig. 7 the brightening-pulse output of the multivibrator, Fig. 8 the gate-pulse output of the multivibrator, Fig. 9 the output of the video amplifier at an instant after that corresponding to Fig. 6, Fig. 10 the output of the delay circuit, Fig. 11 the sweep voltage produced between the horizontally spaced vertically disposed deiiector plates of thc cathode-ray tube, Fig. l2 the radio-frequency trigger pulse, and Fig. 13 the output of the ringing circuit; Figs. 14 and 15 are views of the cathode-ray-tube display, iilustrating the sweep, the echoes and other features; Fig. i6 is a diagrammatic view of circuits and apparatus for providing a modified method of operation, to provide for J tiring any projectile at any position Within the lethal range, or at any time when the projectile occupies such position; Fig. 17 is a diagrammatic view of circuits and apparatus as adapted to operation with sound of supersonic energy, illustrating the dropping of a depth bomb upon a submarine; Fig. 18 is a diagrammatic view illustrating a preferred type of radio-frequency transmitter; Fig. 19 is a similar View of a delay line, such as may be embodied in the system of Fig. 1; and Fig. 2O is a diagrammatic view illustrating a preferred type of variablephase multivibrator.

Any well known ultra-high-frequency radio-locator pulse transmitter may ne employed. A preferred type is illustrated in Fig. 18. Two transmitting triodes 138 and ist@ are connected in parallel, with their

cathodes

142 and 144 connected together through a grounded tuned radiofrequency circuit 146. This tuned circuit may assume any desired form, such as a Lecher line or a tuned cavity (not Sho-wn). The

anodes

148 and 150 of the tubes 138 and itiare shown connected together through a tuned circuit comprising a condenser 152 and a coil 154, connected in parallel. The control-grid electrodes 156 and 15d of the

tubes

138 and 140 are connected together, through a condenser 160, kto a ground 162; and also, through a resister 164, to a grounded plate-supply battery 166. As the condenser 160 is thus connected in parallel mid-point of the plate picked up by the con 16s of the therefore, travels, b y way of the ..Engineering, by Terman.

conductors 134, to the antenna dipole 3, appearing as the said transmitted radio-frequency pulse 126, say, of 50 centimeters wavelength.

The dipole antenna 3 is illustrated in Fig. 1 as positioned at ythe focus of a parabolic or other directive reflector 6. A parasitic reflector 5 may be employed to refiect'the radiation emitted from the dipole 3 back on to the parabolic reflector 6. The parabolic reflector 6 will then direct the energy out towards a target object, such as an airplane 7, and toward a shell or other projectile object 9 that has been fired from a gun (not shown).

Upon reaching the objects 7 and 9, the radio pulses thus propagated towards these objects will become scattered and reflected back toward the parabolic reflector 6 and the dipole 3, to be transmitted, by the conductors 134 and conductors 102, to a radio-frequency-receiver amplifier 11. The received radio-energy shell and target echoes are represented by Fig. 5 as a brief series of

radiofrequency oscillations

124 and 128, respectively, between similarly indicated received pulses 123 picked up directly from the oscillatory transmitted pulses 126 (Fig. 3). The amplifier 11 receives and amplifies these reflected and scattered radio echoes. The energy received by the amplifier 11 may then be detected in a detector 111 to produce direct-current pulses, and then amplified in a video amplifier 130, in well known television fashion. Suitable apparatus for performing this function may be found described, for example, on page 749 of Radio Engineering, by F. E. Terman, 1937 edition. Any well known superheterodyne system may also be used as a receiver, such as is described in Superheterodyne Reception of Micro-Rays, Reeves and Ullrich, Electrical Communications, vol. 16, No. 2, 1937.

The radio-locator transmitter 1, as shown diagrammatically in Fig. l, is connected by

conductors

45 and 174 to an.attenuator-and-rectifier 13, the details of which may be as illustrated in Fig. 18. A center tap 170 of the coil 168 is there shown connected to the grounded side of the attenuator 176 by the conductor 45, Vshown grounded. The other side of the attenuator 17 6 is shown connected by the conductor 174 to one of the terminals of the coil 168. The said one terminal of the coil 168 is shown connected to one side of a rectifier 172 through one side of the attenuator 176. The other side of the rectifier 172 is shown connected, through a radio-frequency-choke coil 178, to the'non-grounded output conductor 136, and a load resistor 180 is connected across the output conductors 136.

The radio energy picked up by the coil 168, therefore, travels not only by way of the conductors 134 to energize the dipole antenna 3, but also, by way of the

conductors

45 and 174, to the attenuator-and-rectifier 13. After passing through the attenuator 176 and the rectifier 172, and through the radio-frequency-choke 178, this energy appears as direct-current Vpulses across the resistor 180. The pulse 182 (Fig. 4) represents that part of the radioenergy pulse that is attenuated and rectified in the attenuator-and-rectier 13. The pulse 182 will obviously take place at the same instant that the pulse transmitter 1 energizes the antenna 3 to emit theradio-frequency pulse 126, and it is used to trigger the sweep generator The attenuator-and-rectifier 13 is connected to a horizontal-sweep-generator circuit 15 by conductors 136,' shown in Fig. 18 connected across -the terminals of the -resistor 180. The generator 15 may, "for example, be of any conventional linear or non-linear type, such, for example, as is illustrated on'page740 of the said Radio This produces a linear or nonlinear horizontal-sweep time base between the horizontally spaced, vertically disposed deliector plates 17 and electron stream horizontally. The saw-tooth-sweepvoltage thus produced between the plates 17 and V19 is 19 of a cathode-ray oscilloscope 21 for deflecting the 'j represented at 62 by Fig. 11. The plate 19 is shown grounded. The video circuits are shown connected to the vetrically spaced horizontally disposed

deector plates

23, 25 by conductors 104 and 10S, respectively.

The same trigger voltage from the attenuator-and-rectifier 13 that triggers the horizontal-sweep generator 15 may trigger also a variable-phase oscillator or strobegenerator, such as a multivibrator 29, to produce pulse outputs in any desired phase relationship to the start of the sweep 62 (Fig. 1l). This may be effected by connecting the attenuator-and-rectifier 13 to the multivibrator 29 by conductors 137.

The variable-phase multivibrator 29 may, for example, be of the type shown in Fig. 20, where

tubes

300 and 301 are shown respectively provided with

cathodes

306 and 307, control-

grid electrodes

304 and 305,

anode plates

302 and 303, and plate-load resistors Rp and Rp. A variable coupling condenser C and a variable resistor R are connected in series to constitute a coupling circuit C-R from the plate circuit of the tube 300 to the grid or input circuit of the tube 301, -the grid 305 of the tube 301 being connected to the junction between the `coupling condenser C and the resistor R. The grid 304 of the tube 300 is similarly connected to 'the junction between the variable coupling condenser C and the variable resistor R', coupling the output circuit of the tube 301 to the input circuit of Ithe tube 300. The condenserC may be charged from a battery 309 through `the resistor R and the plate resistor Rp. The condenser C' may be similarly charged from the battery 309 through the resistor R and the plate resistor Rp.

Let it be assumed that the tube 300 is jus-t cut off. A positive trigger pulse 182 (Fig. 4) is applied .to the grid 304 of the tube 300, causing the tube to burst into conduction.v The voltage at the plate 302 of the tube 300 drops, and the voltage at 'the grid 305 of the tube 301 drops also, since it is coupled to the plate 302 by the condenser C. The tube 301, therefore, cuts off, because of the negative voltage on the grid 305. The voltage of the plate 303 of the tube 301 rises, and causes the grid 304 of the tube 300 to rise further, thus increasing the conduction of the tube 300. When no further voltage' change occurs at the plate 302, the condenser C becomes chargedpositively through the resistors R and Rp from the plate-supply battery 309, until the voltage of the grid 305 rises enough, depending upon the values of C and R, to c-ause the tube301'to conduct and cut off the tube 300. This point is reached at the leading `or left-hand edge ofthe pulse 40 of Fig. 7. When no further changes in vol-tage occur at the plate 303, the condenser C- charges through -the resistor R', the Vsupply battery 309, and the plate load Rp', to restore the grid 304 of the tube 300 to its initial near cut-off condition, The circuit then remains with the tube 301 partially conducting until the next trigger pulse 182 causes the tube 300 heavily to con! Y duct again. The ktime that the process of restoring the grid 304 to-its initial condition consumes is determinedV by the settings of the condenser C and-the resistor-R', and it is this phenomenon that producesthe desired multivibrator-pulse-outputs'. While-the `waveform 40 is illustrated as a rectangularV pulse, this is, of course, idealized;

being, in actual practice, an exponentially dipping spike,

as is well known.

' VA negative pulse 40, Fig.v 7, thus appears' at the plate 303 and -a positive pulse 42, Fig. 8,V at the plate 302 of.V

lthe tube 300. Thewidth of these pulses is controllable,

asV above explained, by the condenser-resistor control Y The time at which these pulses occur, selected and controlled, as above explained, by the phase control -C-R, is shown in Fig. 7Va's occurring at any desireddistance Ra'along the sweep.A Y l The .pulse 40 (Fig. 7) .is fed by conductors 103 between the cathode -60 and the control-grid electrodeV 61 of the cathode-ray oscilloscope 21. Normally, the electrode 61 vis biased negatively with respect to ythe cathode The left-hand edge 60 by, say, a battery 121, to allow a certain intensity of the electron stream to reach the oscilloscope face 27. A B-battery 119 constitutes a source of supply between the cathode 60 and the anode 125 When the brightening pulses arrive between the grid 61 and the cathode 60, the cathode 60 is rendered negative with respect to the grid 61, whereupon the electrons emitted from the cathode 60 are permitted to be accelerated, in the form of an increased stream, past the control grid 61 and Ithe anode 125 of the oscilloscope 21, to impinge finally on the persistent uorescent oscilloscope face 27, brightening that part of the sweep starting with a point corresponding to the distance R3 from the s-tart of the sweep, and brightening a predetermined portion of the sweep of length corresponding to the width of the pulse 40.

After rectification, and preferably also amplification, in the detector-and-video amplier stages 111 and 130, the received direct pulses appear as shown as 63, and the echoes from the shell 9 and the aircraft 7 as shown at 4 and 8, respectively, in Fig. 6. The detected and amplitied video signals are represented by Fig. 6 as they appear at the instant that they are applied to the vertically spaced horizontally disposed

deector plates

23 and 25 to deflect Ithe sweep vertically, as shown in Figs. 14 and 15. The deflection 4, rep-resenting the echo from the shell 9, and the deflection S, representing the echo from the aircraft target 7, are shown in Figs. 14 and 15, together with the sweep 2. In these two Figs. 14 and 15, the brightening pulse 40 of Fig. 7 is shown brightening the part 141 of the sweep associated with the echo 8.

A horizontal-sweep time base 2, the time constant of which depends on the range to be covered, is thus produced on the iluorescent screen 27 of the cathode-ray tube 21, with vertical deections corresponding, in distance from the start of the time base, to the distances from the antenna 3 of the objects 7 and 9 from which the radio waves are reflected or scattered. In accordance with well known radio-location technique, the radio echo of the shell 9 will be shown at a range R1 from the station and that of the object 7 at a range R2.

Since the control electrode 61 is biased negatively with respect to the cathode 60, however, this horizontal sweep will not be very bright on the oscilloscope face 27. At such times as the brightening pulse 40 is applied to the cathode 60 and the grid 61, by way of the conductors 103, from the multivibrator 29, the cathode 60 becomes negative with respect to the control-grid electrode 61. The effect of the said pulse, therefore, as previously described, is to brighten the sweep during the duration of the pulse 40.

When an operator has detected a target appearing as a 'deflection 8 (Figs. 14 and 15), he may adjust the variable-phase multivibrator 29 to bring the edge of the on to the deflection 8, leaving, therebrightening section fore, a selected predetermined portion of the sweep brightened before thel deflection 8, as shown at 141. ofthe portion 141 represents a future position of theprojectile which is traveling towards the target. By suitable design of the time constants or" the multivibrator 29, this brightened portion 141 may be 1 made to correspond in width or range to the lethal distance or range of the projectile. As previously explained, the constants C- of Fig. 20 control the width of the pulse 40 and, therefore, the width of the brightened section 141. 1f the lethal area of the projectile is 170 yards, for example, the product cf the values of the capacitance C andthe resistance R' may `be adjusted to produce a time constant of `approximately one microsecond. As shown in Figs.. 6 and 14, the echo 4 from ythe object 9 has Lnot yet reached its selected future position and Vhas not yet entered the lethal area, shown'as i the horizontal region 141. Any explosion of the projectile would therefore be ineffective at this time.

The instant that the projectile enters within the lethal distance or range, its echo will enter the brightened sec-` tion 141, as shown by Figs. 9 and 15. should be exploded at this time. The method of exploding the projectile at such a time will now be explained.

The gate-pulse output 42 of the multivibrator 29, as shown in Fig. 8, taken, for example, from the plate circuit of the first tube 300 of the multivibrator by the conductors 101, may be fed between the screen grid 10 and the cathode 12 of a gating tube 14. Because of the properties of multivibrators, as previously explained, the timing and the pulse width of the output 42 will be identical with the timing and the pulse width of the output 40, taken from the second tube 301 of the multivibrator, though the pulse 42 is positive as compared with the negative pulse 40. The screen grid 10 may be biased by the battery 16, so as to prevent the tube 14 from conducting except during the application of the positive variable-phase gating pulse 42.

The video output of the receiver, as shown in Fig. 6, may be fed by the

conductors

104, 106 and 105, 107 between the control electrode 18 and the cathode 12 of the gating tube 14 to cause the tube 14 to tend to conduct only during the application of the video pulses, such as the pulses 4 and S. The same video output shown in Fig. 6 may be fed by the

conductors

104, 106, 110 and 105, 107, 109 to a delay circuit 20 of any convenient and well known type, such as an artificial transmission line, a time-constant circuit, or supersonic cell S9, Fig. 19. From the delay circuit, the video output is fed, by conductors 112 and 113 (Fig. l), between a suppressor electrode 22 and the cathode 12 of the gating tube 14. The suppressor electrode 22 is shown negatively biased by a battery 114. The delay mechanism 20 should be adjusted to delay any video signals by an amount of time corresponding to the pulse width of the gating pulse 42, that is, to the lethal range of the burst of the projectile 9. For example, a supersonic cell 59 may be used, as shown in Fig. 19, of material and length such that the video signals, fed to an exciter at one end, such as a piezo-electric crystal 57, and propagated through the cell 59, shall be delayed by a length of time correspending to the pulse width of the pulse 42, and then sent to the suppressor electrode 22 by a receiver piezoelectric crystal SS at therother end of the cell 59. The echo 4 from the projectile 9 and the echo 3 from the object 7, as shown in Fig. 10, will therefore arrive at the suppressor electrode 22 of the gating tube 14 after a period of time displaced from their respective positions in Fig. l0 by approximately the duration of the variablephase pulse output 40 or 42.

In Fig. 10, for illustrative purposes, the echo 4 from the shell 9 is indicated as arriving at the suppressor grid 22 at the same time that the echo 8 from the object 7, as shown in Fig. 9, arrives at the control grid 18 of the gating tube 14, and also during the continued application of the gating pulse 42 from the multivibrator, as shown in Fig. 8, at the screen grid 10 of the gating tube 14.

At approximately the instant of time that the shell 9 enters the lethal area, therefore, the gating tube 14 is opened up by the application of the gating pulse 42 to the screen grid 10, the object pulse 8 to the control grid 18, and the delayed pulse 4 to the suppressor grid 22. The actual instant is somewhat later, after a time corresponding approximately to the width or the variablephase pulse 40 or 42. At that instant of time, the gating tube 14 conducts heavily, thus causing less current to flow through a relay coil 24 (Fig. 1) that is connected, Aby conductors 115, in parallel with the plate or output circuit of the gating tube 14. This diminution of current through the relay coil 24 results in the closing of a relay switch 26, disposed in the plate or output supply of a radio-frequency trigger transmitter 28. The transmitter 2S is connected, by conductors 116,`to energize a further dipole antenna system 30, shown'as a directional system moving together or in synchronism with the reflector 6.

The projectile The transmitter 28, which is normally ineffective to transmit a signal, will thus be rendered effective to send a further and special directional radio signal 46 by way of the antenna system 30, of a different frequency, for example, than the frequency of the transmitter 1, as illustrated by Fig. 12, toward the projectile 9, to explode the projectile.

A receiving-mechanism fuse provided in the shellprojectile 9 will therefore cause the projectile 9 to explode almost immediately. This receiving mechanism may comprise a receiving antenna or antennas. Two dipoles of dimensions resonant to the trigger-signal frequency are shown `at 31 and 64, preferably mounted externally to the fuse 55, as shown in Fig. 2. The antenna or antennas feed into the fuse to energize a lighttransparent radio-frequency cavity resonator 33 of dimensions resonant to the radio waves transmitted by the trigger transmitter 28 (Fig. 1). The radio-frequency resonant cavity 33 may, for example, be constituted of polystyrene or any other similar light-transparent material that serves as a conductor of high-frequency waves. The resonator may be lled with an illuminating agent; for example, the rare gas neon.

The antennas 31 and 64 are shown connected to the resonant cavity 33 by

coaxial lines

47 and 48, respectively. The radio-frequency energy thus fed into the gas in the cavity resonator 33 results in ionizing the gas therein, which therefore becomes illuminated. The illumination may be focused by a lens 35 upon a photocell 37, connected in series with a source of voltage, such as a battery 49 and an igniting mechanism 39, such as a charge, as of powder, for exploding the explosive mixture of the shell or the projectile. When the trigger transmitter 28 sends a radio signal that is received by the antennas and energizes the cavity 33, therefore, the light from the ionization of the cavity resonator causes current to flow in the light-sensitive circuit of the photocell 37, upon which the light is focused, thereby causing aV suiciently large current to flow through the charge 39 to ignite the charge 39 and to explode the shell.

If desired, the light-transparent radio-cavity resonator 33 may be maintained periodically ionized by a striking potential from an energy source 50, as shown in Fig. 2. When the radio energy from vthe trigger transmitter 28 is conveyed into the cavity resonator, the gas will become further ionized, producing an increased intensity of light discharges and a greater current in the photo'cell circuit for setting off the mechanism 39. Y

To prevent premature operation, thereby further to control the explosion of the projectile at any desired time, or when it occupies any desired position, from any desired remote point, an arming device, such as an arming propeller screw 41, may be provided to maintain the photocell circuit open, by holding down a switch 43, for example, until such time as the projectile has travelled a desired length of time. At the end of this time, the arming propeller 41 will have unscrewed itself from the Vfuse nose in ight, thereby releasing the switch 43, and completing the photocell circuit in the fuse for' operation upon the receipt of the energizing radio-trigger signal from the remote point. Y

It may be desired to insure that the shell 9 shall re at any given time after it shall get within lethal range, or y when it occupies any desired position within Vthe lethal range. SuchV an occasion mayY arise, for example, in the event that the radio-locator antenna system, 6 should happen notl to pick up the signal from the shell 9 or the target 7 until after the shell shall have already entered the lethal area. y

To the attainment of this end, Vthe video voutput of the receivermay also be fed by conductors 104, 10S to a ringing or a poorly damped high-frequency oscillating circuit 108, as shown in Fig. 16. Each video signal, therefore,:will produce a Vtrain of oscillations, the half-period of which will be much less than the'width of thepulses of Vthe radio-frequency transmitter 1. As shown in Fig. 13

8 whole trains of positive and negative oscillations may thus be produced by each video pulse, a train 51 corresponding to the echo 4, as shown in Fig. 9, and a train 52 corresponding to the echo 8. These trains of oscillations may be fed by conductors 122 (Fig. 16) between the screen grid 32 and the cathode 38 of another gating tube 34, in order to lift the bias thereon provided by, say, ya biasing battery 120.

The variable-phase gating pulse output 42 of the multivibrator 29 may also be lfed by the conductors 101, not only between the screen grid 10 and the cathode 12 of the rst gating tube 14, as previously described, but also between the control electrode 36 and the cathode 38 of the second gating tube 34, as shown in Fig. 16. This may be effected simultaneously with the application of the trains of

oscillations

51 and 52 to the screen grid 32. The tube 34 will therefore open up to conduct each positive oscillation for the duration of the gating pulse 42. The output of the tube 34 may be inverted in any well known video amplifier 53, so that a series of closely spaced positive pulses shall be available for application to the suppressor grid 22 of the main gating tube 14. The delay circuit 20, of course, will be disconnected from' the suppressor grid 22 during this mode of operation.

Since the half-period of the

oscillations

51, 52 is small compared with the width of the video signals 4 and 8, the main gating tube V14 will open up on the application of a video signal 4 from a projectile 9 at essentially any time during the gating period of the output 42 and, therefore, at essentially any time after theY projectile 9 enters within the lethal area of the object 7.

The circuits and apparatus of Fig. 17 may be identical with those shown in Fig. 1, except that a supersonic transmitter 201 may V-replace the radio-locator-transmitter system 1, 6, a supersonic receiver 211 may replace the radio-frequency amplifier 11, `and a supersonic trigger transmitter 228 may replace the radio-frequency trigger transmitter 28. These are all shown carried by a ship 219. A depth bomb projectile 209 maybe equipped with sound receivers, such 'as quartz crystals 56, that may be connected in similar fashion to the connections of the antennas 31 and 64 of Fig. 2, and that may be connected into a cavity 233, resonant to the electric oscillations of the trigger supersonic transmitter 228,' inside a fuse mechanism 255 on or within the depth bomb. The cavity 233 may be ofthe same nature as the gas-filled, lighttransparent cavity'resonator 33 illustrated in Fig. 2.

The electric oscillations produced by the crystals 56 in response to the ultrasonic waves from the

transmitter

2,28, and thus'fed into the gas in the cavity resonator 233, will ionize this gas, Vwhich will therefore become illuminated. The effect of the illumination is manifestedrin a photo-cell circuit connected in series with a'batteryV When the ultrasonic trigger l transmitter energizes the cavity 233, therefore, the light land an igniting charge.

produced in the cavity responsive to the ionization of the gas therein causes current to ow in the light-sensitive photo-cell cir-cuit. l exploding' the ash-can in a manner similar to that described in connection with theV cavity'V resonator 33 and theV photo-cell circuit, of Fig. 2. Y

Employing thisfinvention, a submarine 207wou1d not be alerted bythe explosion'of depth-charges Yor bombsfV that might miss their mark, but would be subjected to injury lby those depth bombs that would become exploded without notice when they are within lethal range ofthe submarine. L Y p The supersonic transmitters and receivers mentioned may, for example, be magnetostrictive or piezoelectric, according to well known technique. The supersonic pulse transmitter 201 and thesupersonic yreceiver 211, for example, may be of thevtype described in United States Letters Patent 2,084,845, issued June 22, 1937, to Edward L. Holmes@ The ltrigger transmitter 228 may, for example, be of any well known piezo-electric type.

This results in igniting the charge andY Other rand further modifications will occur to persons skilled in the art, and all such are considered to fall within the spirit and scope of the invention, as defined in the appended claims.

What is claimed is:

l. An electric system having, in combination, means for detecting an explodable object and producing a voltage signal corresponding to the same, means for producing a voltage signal indicative of the occupation by the object of a predetermined position, and means separate from the ydetecting means for thereupon in response to the said voltage signals automatically exploding the object during the continued detecting of the object.

2. An electric system having, in combination, a radio locator for detecting, producing voltage signals indicative of and indicating the track of objects one of which is provided with explodable means, voltage-producing means for continuously selecting along the indicated track la future position of the explodable object within a preselected range of another of the objects, and means separate from the radio locator and response to the voltage ofthe selecting means and to the said voltage signals of the radio locator for automatically energizing the explodable means to explode the explodable object when it approaches within the preselected range during the continued detection by the radio locator.

3. An electric system having, in combination, radioL locating means for detecting, producing voltage signals indicative of and indicating the track of an object provided with explodable means, voltage-producing means for continuously selecting along the indicated track a future position of the explodable object, and radicecontrolled means separate from the radio-locating means responsive to the voltage of the selecting means and to the said voltage signals of the radio-locating means for automatically energizing the explodable means to explode the object when it reaches the future position during the continued detection by the radio-locating means.

4. An electric system having, in combination, a radiolocator system for detecting lan object and an explodable projectile traveling towards the object and provided with explodable means, a cathode-ray tube, means for displaying upon the cathode-ray tube a voltage signal received from the object by the radio-locator system, voltageproducing means for selecting an area upon the cathoderay tube in the proximity of the object detected by the y radio-locator system as displayed on the cathode-ray tube,

and mean-s separate from the radio-locator system responsive to the said voltage signal of the radio-locator system and to the voltage of the selecting means for automatically energizing the explodable means to explode the explodable projectile when it enters the said proximity during the continued detection by the radio-locator system.

5. In an electric system having means for propagating radio waves toward objects in space, radio-receiving means for receiving radio waves from both a target in space and an explodable projectile traveling toward the target provided with energy-receiving means and means connected with the radio-receiving means for exploding the projectile in response to an energy signal received by the energyreceiving means, normally ineective means separate from the radio-wave propagating means for transmitting an energy signal to the energy-receiving means, a display, means controlled in accordance with the radio waves received from both the target and the projectile for producing indications of the distance between the target and the projectile upon the display, means for continuously selecting-a predetermined value of distance between the target and the projectile upon the display, and means responsive to the selecting means and to the received radio waves and operable when the dist-ance between the target and the projectile becomes less than the predetermined value to render the transmitting means effective to transmit the energy signal to the energy-receiving means, thereby to 10 effect the explosion of the projectile during the continued radio-wave propagation by the propagating means.

6. In an electric system leaving means for propagating radio waves toward objects in space, radio-receiving means for receiving radio waves from both a target in space and a projectile traveling toward the target provided with `energy-receiving means, normally ineffective means separate from the radio-wave propaga-ting means for transmitting an energy signal to the energy-receiving means, a display, means controlled in accordance with the radio waves received from both the target and the projectile for producing indicationsofthe distance between the target and the projectile upon the display, means for continuously selecting a predetermined value of distance between the target and the projectile upon the display, and means responsive to the selecting means and to the received radio waves and operable when the distance between the target and the projectile becomes less than t-he predetermined value to render thetransmitting means effective to transmit the energy signal to the projectile energy-receiving means during the continued radio-wave propaga-tion by the propagating means.

7. An electric system having, in combination, means for propagating pulses of radio waves towards both a target and an explodable projectile traveling toward the target provided with energy-receiving means and means connected with the receiving means for exploding the projectile in response to an energy signal received by the energy-receiving means, radio-receiving means for receiving the pulses of radio waves after reflection and scatter from the target and the projectile, normally inetective means separate from the radio-wave propagating means for transmitting an energy signal to the energy-receiving means, a cathode-rray-tube display, means synchronized with the propagating means for producing a time case upon the cathode-ray-tube display, means controlled by the radio-receiving means for indicating the instants of reception of the reccted and scattered radio waves from the target and from the projectile upon the time base, thereby to indicate the relative distances or" the target and of the projectile, means for continuously selecting a portion of the time base corresponding to a predetermined value of distance from the target, and means responsive to the selecting means and to the received radio waves and operable when the distance between the target and the projectile becomes less than the predetermined value to render the transmitting means effective to transmit the energy signal to the energy-receiving means, thereby to effect the explosion of the projectile during the continued radio-'wave propagation by the propagating means.

8. An electric system having, in combination, a radiolocator system for detecting and indicating the track of relatively movable objects one of which is provided with energy-receiving means and producing voltages indicative of the relative positions of the detected objects, means comprising a further voltage-producing selecting means for producing a further voltage correlated with respect to the said voltage indicative of another of said objects and continuously corresponding toa selected assumed future position of the said one object within a preselected range of the said another of the objects, a normally inet'- fective electric circuit that can be rendered eiect-ive only upon the substantially simultaneous application thereto of the said voltages indicative of the said one and the said other objects detected by the radio-locator system andthe said further .voltage produced by the selecting means at the time when the said one object approaches within the said preselected range, means for feeding the said voltages pro-'duced by the radio-locator system and the'said further voltage produced by the selecting means tothe normally inelfective electric circuit, thereby automatically to render the 'electric circuit eliective at the said time, and means responsive to the rendering eliective of the electric circuit for thereupon transmitting an energy 11 signal to the said energy-receiving means of the said one object.

9. An electric system having, in combination,Y a radiolocattor system for detecting and indicating the track of relatively movable objects one of which is provided with radio-receiving means and producing voltages indic-ative of the relative positions of the detected objects, means comprising a further voltage-producing selecting means for producing a further voltage correlated with respect to the said voltage indicative of another of the said objects and continuously corresponding to a selected assumed future position of the said one object within a preselected range of the said another of the objects, a normally ineffective electric circuit that can be rendered effective only upon the substantially simultaneous application thereto of the said voltages indicative of the said one and the said other objects detected by the radio-locator system and the said further voltage produced by the selecting means at the time when the said one object approaches VWithin the said preselected range, means for feeding the said voltages produced by the radio-locator system and the said further voltage produced by the selecting means to the normally ineffective electric circuit, thereby automatically to render lthe electric circuit effective at the said time, and means responsive to the rendering effective of the electric circuit for thereupon transmitting a radio signal to the said radio-receiving means of the said one object.

l0. An electric system having, in combination, a radiolocator system for detecting and indicating the track of relatively movable objects one of which is explodable and producing voltages indicative of the relative positions of the detected objects, means comprising a further voltageproducing selecting means for producing a further voltage correlated With lrespect to the said voltage indicative of another of the said objects and continuously corresponding to a selected assumed future position of the said one object within a preselected'range of the said another of the objects, a normally ineffective electric circuit that can be rendered eective only upon the substantially simultaneous application Ithereto of the said voltages indicative of the said one Iand the said other objects detected by the radio-locator system and the said further voltage produced by the selecting means `at the time when the said one object'approaches within the said preselected range, means for feeding the said voltages produced by the radio-locator system and the 'said further voltage produced by the selecting means -to the normally ineffective electric circut, Athereby automatically to render the electric circuit effective at the said time, and means responsive to the rendering effective of the electric circuit for exploring the said one object. Y

ll. An electric system having, in combination, `a rad-iolccator' system for detecting and indicating the track of relatively -movable'objects one of which is provided with radio-receivingmeans and for producing voltagesY indicative of the relative positions of the detected objects,

fective electric circuit, thereby automatically to render the electric circuit effective at the time when the said one object approaches within the said preselected range, and means responsive to the rendering eifective of the electric circuit for thereupon transmitting a radio signal to the said radio-receiving means of the said one object.

12. An electric system having, in combination, a radioenergy locator `system provided with means for propagating pulses of radio energy toward and receiving the pulses of sound energy after rellection and scatter from relatively movable objects one of which is provided with sound-energy-receiving means and means for producing pulse voltages from the pulses `of radio energy received from the objects, thereby to indicate the `track and measure the range of the relative positions of the objects, means comprising a further voltage-producing selecting means for producing a `further voltage correlated with respect to the said voltage indicative of another of the said objects land continuously corresponding to -a selected means comprising a further voltage-producing selecting means for producing a further voltage correlated with respect to the said voltage indicative `of another yof the said objects and continuously corresponding to a `selected assumed future position of the 4said one object within a preselected range of the said another of the objects,

means for producing voltages rcorresponding to butV delayed from `the :said voltages'produced by the radiolocator system an interval of time corresponding sub-. stantially to the .said p'reselectedrange, la normally inefv feet-ive electric circuit that can be rendered effective only upon the 'substantially simultaneous application thereto of the said voltage indicativeV of the said otherobject detected by ythe radio-locator system, the Vdelayed voltage indicative of the said one object and the said further voltage produced by the selecting means, means for feeding the said voltage produced by the radio-locator sys- V tern, the said delayed voltage and the said furthervoltage produced byV the selecting means to the normally inefassumed future position of the said one `object-within a preselected range of the said another of the objects, means for producing pulse voltages corresponding to but delayed from the said pulse voltages produced by the radio-energy-locator system an interval of time corresponding substantially to the said preselected range, a normallyV ineffective electric circuit that can be rendered effective `only upon the substantially simultaneous application thereto of the said pulse voltage indicative of the said other object produced by the radio-energy-locator system, the delayed pulse voltage indicative of the said `one object and the said further voltage produced by the selecting means, means for feeding -the -said pulse voltages produced by the radio-energy-locator system, the said delayed pulse voltage and the said further voltage produced by the :selecting means to `the normally ineffective electric circuit, thereby to render the electric circuit effective at the time when the said lone object approaches 'within the said preselected range, and means responsive yto the rendering effective of the electric circuit for thereupon transmitting a radio-energy signal to the said one Vobject for reception in the said jradio-energy-receiving object, a cathode-ray tube, means for displaying upon',

the` cathode-ray tube a voltage pulse corresponding to 1a signal received yfrom theobject by the locato-r system, means Yfor producing a gate voltage pulse of duration greaterl than that of the signal voltage pulse and for controlling the gate pulse to :select aregion upon' the cathode-ray tube corresponding to a region in the proximity of the object, and -a transmitter responsive to the voltages of the signal iand gate voltage'pulses for K automatically `transmitting -afurther sig-nal to the projectile when it is detected by 'the locator system` as having entered the said proximity.V

14. Anelectric system having, in combination, anrob-V ject locator system provided with means for directionally transmitting energy to and receiving energy from'an object in space and producing voltage signals Yindicative 'of the position of the object in space, means for producing a further voltage Correspon'ding to an assumed future position of the object in space, a normallyV ineffective object signalling system separate from the locator system and provided with means for directionally transmitting .a signalwheneffective, means for causingthe signallingsystem-directional-transmitting means Vto be directed Vtovvard the same object located by Vthe object locator 'systern, and means responsive to the voltage signals produced by the locator system and to the-furthervoltage for rendering the signalling system effective at a time when the object has'entered the said assumed future position, thereby to thereupon transmit a signal to the ob- Vmeans, means connected with the "I3 ject during the continued object location by the locator system. A

15. An electric system having, in combination, an object radio locator system, l provided with means for dir'ectionally transmitting radio energy to and receiving radio energy from an object in space and producing Voltage signals indicative of the position of the object in space, means for producing a further voltage corresponding to an assumedfuture position of the object in space, a normally ineffective object radio signalling system separate from the locator system and provided with means for directionally transmitting a radio signal when effective, Ymeans for causing .the signalling-systemdirectional-transmitting means-to be directed toward the same object located by the object locator system, and means responsiveto the voltage signals produced by the locator system and to the further voltage for rendering the signalling system effective at a time when the object has entered the said assumed future position, thereby to thereupon transmit a radio signal to thel object during the continued object location by the locator system.

16. An electric system having, in combination, a pulseenergy locator system for detecting an object in space and a projectile traveling towards the object and producing pulse voltage signals indicative of the positions in space of the object and the projectile, means for producing a gate voltage pulse of duration greater than that means for controlling it is detected by the locator system as having reached thev said future position.

17. An lelectric system having, in combination, an electromagnetic pulse-energy locator system for detecting an object in space and a projectile traveling towards the object and producing pulse voltage signals indicative of the positions in space of the object and the projectile, means for producing a gate voltage pulse of duration greater than that of the pulse voltagev signals, means for controlling the gate pulse to correlate its position with respect to the said pulse voltage signal indicative of the position in space of thel object in order to correspond to an assumed future position of the projectile, and an electromagnetic transmitter responsive to the voltages of the pulse voltage signals and the gate pulse for automatically transmitting a further electromagnetic signal to the projectile when it is detected by the locator system as having reached the said future position.

1S. An electric system having, in combination, radiolocating means lcomprising means for detecting, means for producingl voltage signals indicative of and means for indicating the track of any object provided with energyreceiving means, voltage-producing means for continuously selecting along the indicated track anfuture position of the object, and radio-controlled means ,separate from the radio-locating means responsive to the voltage of the selecting means and to the Vsaid voltage signals of the radio-locating means for energizing the object energ receiving means when the object reaches the future position during the continued detection by the radiolocating means.

19. An electric system having, for detecting an object provided in combination means with energy-receiving l detecting means for producing a lvoltage signal corresponding to the object, means for producing a .voltage signal indicative of the occupation by the object of a predetermined position, and means separate from the detecting means for thereupon in response to the said voltage signals of the cccupation by the'object of a predetermined position ener- I4 gizing the object energy-receiving means during the con.- tinued detecting of the object.

20. In a radio object location system in which transmitted pulses of radio frequency energy are reecbed from a missile to be received as echo pulses by said system and indicate the distance therefrom of said missile, the combination of means for producing pulses corresponding to pulses transmitted by the said system, the produced pulses being delayed with from said producing being activated by a coincidence between the-delayed pulses and the echo pulses, control means connected to and operated by the activation of said gating switch means for producing a predetermined signal, and means in said missile responsive to the said signal for detonating said missile.

21. In a radio object location system in which transmitted pulses of radio frequency energy are reflected from a missile to be received as echo pulses by said system and indicate the distance therefrom of said missile, the combination of means for producing pulses delayed from corresponding pulses transmitted by the said system by time corresponding to a predetermined target range, normally deactivated gating switch means receptive of said echo pulses received by said system and system for detecting at least one missile by means of transmitted pulses of radio of time corresponding to -24. An electric system having, in combination, Ian energy locator for detecting objects one of which is provided with explodable means, voltage-producing means for continuously selecting a future position of the explodable object within a preselected range of another of the objects to be Adestroyed by the explodable object, and means separate from the energy locator operable at a remote point and responsive to the voltage of the selecting means and to the energy locator for automatically energizing the explodable means to explode the explodable object when it approaches within the preselected range during the continued detecting of the objects by the Venergy locator.

25. An electric system having, in combination, energylocating means for detecting an object provided with explodable means, voltage-producing means for continuously selecting a future position of the explodable object, and energy-controlled means separate lirom the energylocating means responsive to the voltage of the selecti-ng means and tothe energy-locating means for automatically energizing the explodable means to explode the object when it reaches the future position during the continued detecting of the object by the energy-locating means.

26. An electric system having, in combination, energyreceiving means for receiving energy Waves from both a target anda projectile traveling toward the target provided with energy-receiving means, normally ineffective means for transmitting an energy signal of an entirely different character than the energy waves received by the energy receiving means to the energy receiving means, a display, means controlled in accordance with the energy Waves received from both the target and the projectile for producing indications of the distance between the target and the projectile upon the display, voltage-producing means for continuously selecting a predetermined value of distance between the target and the projectile upon the display, and means responsive to the voltage of the selecting means and to the received energy waves and operable when the distance between the target and the projectile becomes less than the predeterminedvalue to render the transmitting means effective to transmit the energy signal to the projectile energy-receiving means.

27. An electric system having, in combination, means for propagating pulses of energy waves towards both a target and an explodable projectile traveling toward the target provided with energy-receiving means and means connected with the receiving means for exploding the projectile in response to an energy signal received by the energy-receiving means, energy-receiving means for receiving the pulses of energy waves after reflection and Ascatter from the target and thel projectile, normally ineffective means separate from the propagating means for transmitting an energy signal to the energy-receiving means, a cathode-.ray-tube display, means synchronized with .the propagating means for producing a time base `upon the cathode-ray-tubeI display, means controlled by the energy-receiving means for indicating the instants of reception of the reflected and scattered energy waveskfrom the target and from the projectile upon the time base, thereby to indicate the relative distances' of the vtarget and of the projectile, voltage-producing means forV plodable means to explode the explodable object when it approaches within the preselected range during the continued detecting of the objects by the radio locator.

29. Anv electric system having, in combination, radiolocating means for detecting an object provided with explodable means, voltage-producing means for continuously selecting a future position of the explodable object, and radio-controlled means separate from the radio-locating means responsive to the voltage of the selecting means and to the Vradio-locating means for automatically energizing the explodable means when it reaches the future position during the continued detecting of the object by the radio-locating means.

30.V An electric system having, in combination, radioreceiving means for receiving radio waves from both a target and a projectile traveling toward the target provided withradio-receiving means, Vnormally ineffective means for transmitting a radiosignal of anventirely different character than the radio waves received by the radio receiving `means to the radio receiving means, a display, means controlled in accordance with the radio Vwaves received from both the target andthe projectile ing means for continuously selecting a predetermined v'alue of distance between the'target and the projectile upon the display, and means responsive to the voltage of the selecting means and to the received radio waves and operable when the distance between the target and the projectile becomes less than the predetermined value to render the transmitting means effective to transmit the energy signal to the projectile energy-receiving means.

3l. An electric system having, in combination, means for propagating pulses of radio waves towards both a target and an explodable projectile traveling toward the target provided with radio-receiving means and means connected with the receiving means for exploding the projectile in response to a radio signal received by the Y radio-receiving means, radio-receiving means for receiving the pulses of radio waves after reection and scatter from the target and the projectile, normally ineffective means separate fromthe propagating means for transmitting an energysignal to the radio-receiving means, a cathode-ray-tube display, means synchronized with the propagating means'for producing a time base upon the cathode-ray-tube display, means controlled by the radioreceiving rmeans for indicating the instants of reception of the reilected and scattered energy waves from the target and from the projectile upon the time base, thereby to indicate the relative distances of theV target and of the projectile, voltage-producing means for continuously selecting a portion of the time base corresponding to a predetermined value 'of `distance fromV the target, and

means responsiveto the voltage of the selecting means Vand to the received radio vwaves-and operable when the continuously selecting a portion-of the timebase corresponding to a predetermined value of distance from the target, and means responsiveyto the voltage of the selecting means and to the received energy-waves and operable when the distance between the target and the projectile becomes less than the predetermined value lto render the transmitting means effective to transmit the energy signal to the energy-receiving means, thereby to effect the explosion of the projectile during the continued propagation and reception of the energy waves.

28. An electric system having, in combination, a radiok ,tinuously' selecting a future position of the explodable .object within a preselected range of another of theobjects to be destroyed by the explodable object, and means seplocator for detecting objects one of which is provided Y lwith explodable means, voltage-producing means for conless than the predetermined value to render the transmitting means effective tojtransmit the radio signal to the radio-receiving means, therebyQ to effect the explosion of the projectilefduring the continued propagation and reception of the radio waves.

32. An electric system having, lin combination, an energy locator for detecting objects one of which is provided with Y signal-receiving Vmeans, voltage-producing means for continuously selecting a future position of the said one object within a preselected range of another of the objects, and means operable at a point remote from the objects-and responsive to the voltage of the selecting meansand vto Vthe locator forautomatically sending a signal to the signal-receiving means of the, said one object when it approaches the preselectedrange. V 1.--

33. An electric system having,- inV combination, energylocating means for. detecting anV object provided with signal-receiving means, voltage-producing means for kcontinuously selectinga future position of the said object,

to explode the object and signal-controlled means responsive to lthe voltage of the selecting means and to the energy-locating means for automatically energizing the object-signal-receiving means when the object reaches the future position.

34. An electric system having, in combination, an energy locator for detecting objects one of which is provided With explodable means, voltage-producing means for continuously selecting a future position of the eX- plodable object within a preselected range of another of the objects to be destroyed by the explodable object, and means separate from the energy locator operable at a point remote from the explodable object Iand responsive to the voltage of the selecting means and to the energy locator for automatically causing the explodable means to explode the explodable object when it approaches Within the preselected range during the continued detecting of the object by the energy locator.

35. An electric system having, in combination, a radio locator for detecting objects one of which is provided with explodable means, voltage-producing means for continuously selecting a future position of the explodable object Within a preselected range of another 'of the 0bjects to be destroyed by the explodable object, and means separate from the radio locator operable at a point remote from the said one object and responsive to the voltage of the selecting means and to the radio locator for automatically causing the explodable means to eX- plode the explodable object when it approaches within the preselected range during the continued detecting of the objects by the radio locator.

36. An electric system having, in combination, radiolocating means for detecting an object provided with explodable means, voltage-producing means for continuously selecting a future position of the explodable object, and radio-Wave transmitting means normally occupying one of two conditions of energization, the radio-wave transmitting means being separate from the radio-locating means and responsive to the voltage of the selecting means and to the radio-locating means for automatically occupying its other condition of energization to cause the explodable means to explode the object when it reaches the future position during the continued detecting of the object by the radio-locating means.

37. An electric system having, in combination, energylocating means for detecting an object provided with signal-receiving means, voltage-producing means for continuously selecting a future position of the said object, and signal-transmitting means for signaling the signalreceiving means and normally occupying one of two conditions of energization, the signal-transmitting means being responsive to the voltage of the selecting means and to the energy-locating means for automatically occupying the other condition of energization to produce an indication at the object-signal-receiving means when the object reaches the future position.

38. An electric system having, in combination, an energy-locator system for detecting relatively movable objects one of which is provided with energy-receiving means and producing voltages indicative of the relative positions of the detected objects, means comprising a further voltage-producing selecting means for producing a further voltage correlated with respect to the said voltage indicative of another of the said objects and continuously corresponding to a selected assumed future position of the said one object Within a preselected range of the said another of the objects, a normally ineffective electric circuit that can be rendered effective only upon the substantially simultaneous application thereto of the said voltages indicative of the said one and the said other objects detected by the energy-locator system and the said further voltage produced by the selecting means at the time when the said one object approaches Within the said preselected range, means for feeding the said voltages produced by the energy-locator system and the said further voltage produced by the selecting means to UJI the normally ineffective electric circuit, thereby automatically to render the electric circuit effective at the said time, and means responsive to the rendering effective of the electric circuit for thereupon transmitting an energy signal to the said energy-receiving means of the said one object.

39. An electric system having, in combination, an energy-locator system for detecting relatively movable objects one of which is provided with energy-receiving means and producing voltgges indicative of the relative positions of the detected objects, means comprising a further voltage-producing selecting means for producing a further voltage correlated with respect to the said voltage indicative of another of the said objects and continuously corresponding to a selected assumed future position of the said one object within a preselected range of the said another of the objects, a normally ineffective vacuumtube gating electric circuit that can be rendered effective only upon the substantially simultaneous application thereto of the said voltages indicative of the said one and the said other objects detected by the energy-locator system and the said further voltage produced by the selecting means at the time when the said one object approaches within the said preselected range, means for feeding the said voltages produced by the energy-locator system and the said further voltage produced by the selecting means to the normally ineffective electric circuit, thereby automatically to render the electric circuit effective at the said time, and means responsive to the rendering effective of the electric circuit for thereupon transmitting an energy signal to the said energy-receiving means of the said one object.

40. An electric system having, in combination, an energy-locator system for detecting relatively movable objects one of which is explodable and producing voltages indicative of the relative positions of the detected objects, means comprising a further voltage-producing selecting means for producing a further voltage correlated with respect to the said voltage indicative of another of the said objects and continuously corresponding to a selected assumed future position of the said one object within a preselected range of the said another of the objects, a normally ineffective electric circuit that can be rendered effective only upon the substantially simultaneous application thereto of the said voltages indicative of the said one and the said other objects detected by the energylocator system and the said further voltage produced by the selecting means at the time when the said one object approaches within the said preselected range, means for feeding the said voltages produced by the energy-locator system and the said further voltage produced by the selecting means to the normally ineffective electric circuit, thereby automatically to render the electric circuit effective at the said time, and means responsive to the rendering eiiective of the electric circuit for exploding the said one object.

4l. An electric system having, in combination, an energy-locator system for detecting relatively movable objects one of which is provided with energy-receiving means and for producing voltages indicative of the relative positions of the detected objects, means comprising a further voltage-producing selecting means for producing a further voltage correlated with respect to the said voltage indicative of another of the said objects and continuously corresponding to a selected assumed future position of the said one object within a preselected range of the said another of the objects, means for producingr voltages corresponding to but delayed from the said voltages produced by the energy-locator system an interval of time corresponding substantially to the said preselected range, a normally ineffective electric circuit that can be rendered effective only upon the substantially simultaneous application thereto of the said voltage indicative of the said other object detected by the energylocator system, the delayed voltage indicative of the said 19 Y one object and the said further voltage produced by the selecting means, means for feeding the said voltage produced by the energy-locator system, the said delayed voltage and the said further Voltage produced by the selecting means to the normally ineiective electric circuit, thereby automatically to render the electric circuit effective at the time when the said one object approaches Within the said preselected range, and means responsive to the rendering effective of the electric circuit for thereupon transmitting an energy signal to the said energyreceiving means of the said one object.

42. An electric system having, in combination, an energy-locator system for detecting relatively movable objects one of which is explodable and for producing voltages indicative of the relative positions of the detected objects, means comprising a further voltage-producing selecting means for producing a further voltage correlated with respect to the said voltage indicative of another of the saidobjects and continuously corresponding to'a selected assumed future position of the said one object within a preselected range of the said another of the objects, means for producing voltages corresponding to but delayed from the said voltages produced by the energylocator system an interval of time corresponding substantially to the said preselected range, a normally ineffective electric circuit that can be rendered eiective only upon the substantially simultaneous application thereto of the said voltage indicative of the said other object detected by the energy-locator system, the delayed voltage indicative of the said one object and the said further voltage produced by the selecting means, means for feeding the said voltage produced by the energy-locator system, the said delayed voltage and the said further voltage produced by the selecting means to the normally ineiective electric circuit, thereby automatically to render the electric circuit effective at the time When the said one object approaches Within the said preselected range, and means responsive to the rendering effective of the electric circuit for thereupon exploding the said one object.

43. An electric system having, in combination, an energy-locator system provided with means for propagating pulses of energy toward and receiving the pulses of energy after reilection and scatter from relatively movable objects one of which is provided with energy-receiving means and means for producing pulse voltages from the pulses of energy received from the objects, thereby to measure the range of the relative positions of the objects, means comprising a further voltage-producing selecting means yfor producing a further voltage correlated With respect to the said voltage indicative of another of the said objects and continuously corresponding to a selected assumed future position of the said one object within a preselected range of the said anotherof the objects, means for producing pulse voltages corresponding to but delayed from the said pulse voltages produced by the energy-locator system an interval of time correspending substantially to the said preselected range, a

tube, means for displaying normally ineffective electric circuit that can be rendered etective only upon thesubstantially simultaneous application thereto of the said pulse voltage indicative of the said other object produced by the energy-locator system, the delayed pulse voltage indicative ofthe said one lobject and the said further voltageV produced bythe selecting means, -means for feeding the said pulse voltages produced byv the energy-locator system, the Vsaid delayed pulse voltage and the said `further voltage produced by the selecting means Vto the normally inetective electric circuit, thereby to render the electric circuit effective at the time when theV said rone object approaches Within the said preselected range, and means responsive to the rendering effective of the electric circuit for thereupon transmitting an energy signal lto the said one object for reception in the saidenergy-receiving means. j

44. An electric system having, in combination, a pulse-energy locator system for detecting an object and a projectile traveling towards the object, a cathode-ray upon the cathode-ray tube a voltage pulse corresponding to a signal received from the object by the locator system, means for producing a gate voltage pulse of duration greater than that of the signal voltage pulse and for controlling the gate pulse to select a region upon the Vcathode-ray tube corresponding to a region in the proximity of the object, and a transmitter responsive to the voltages of the signal and gate voltage pulses for automatically transmiting a furher signal to the projecile when it is detected by the locator system as having entered the said proximity. v

References Cited in the file of this patient UNITED STATES PATENTS 915,28()Y Fessenden Mar. 16, 1,388,932 Centervall Aug. 30, 1921 1,769,203 Buckley, Iuly 1, 1930 2,110,552 Hayden Mar, 8, 1938 2,123,242 Hollman July 1,2, 1938 2,361,177 Chilowsky Oct'. 24, 1944 2,383,286 Beers Aug. 21, 1945 2,399,426 Bradley Apr. 30, 1946 2,403,567 Wales July 9, 1946 2,409,462 Zworykin Oct. 15, 1946 2,411,788 Hammond Nov. 26, 1946 2,412,751 Rochester Dec. 17, 1946 2,413,621 Hammond Dec. 3l, 1946 2,421,085 Rylsky May 27, 1947 2,455,265 Norgaard Nov. 30, 1948 2,463,233 Alexanderson Mar. 1, 1949 2,481,515 Isbister Sept. 13, 1949 2,494,339 Keister Jan.l0, 1950 2,514,677 Skellett July 11', 1950 2,557,949 Deloraine lune 26, 1951 FOREIGN PATENTS v 91,592 Sweden Feb. 24, 1938