US3269314A - Radio proximity fuze - Google Patents

Description

Aug. 30, 1966 R. H. VARIAN 3,269,314

RADIO PROXIMITY FUZE Filed Dec. '7, 1942 2 Sheets-Sheet 1 l OSCILLATOR 56 FILTER FILTER FILTER FILTER Fl LTEP FILTER PECT RECT RECT RECT RECT RELCT INVENTOR 4 RUSSELL. h. MGR/RN Y my ' ATTORNEY Aug. 30, 1966 R. H. VARIAN RADIO PROXIMITY FUZE Filed Dec. 7, 1942 7 a 3 1oi 1: 10 1o L TUNED UHF: OSCILLATING DETECTOR 2 Sheets-Sheet 2 INVENTOR A USSELL United States Patent 3,269,314 RADIO PROTY FUZE Russell H. Varian, Wantagh, N.Y., assignor to Sperry Rand Corporation, a corporation of Delaware Original application July 8, 1941, Ser. No. 401,474. Divided and this application Dec. 7, 1942, Ser. No. 468,308

2 Claims. (Cl. 102-702) This application is a division of Serial No. 401,474, filed July 8, 1941, for Radio Controlled Projectiles, now Patent No. 2,414,103.

This invention relates, generally, to the use of ultrahigh frequency radio Waves for controlling bombs and other explosive missiles such as rocket missiles, aerial torpedoes, shells, etc., after the same have been discharged from their releasing or projecting apparatus and during flight.

Owing to the constantly increasing height at which military aircraft navigate, it is highly desirable to control explosive missiles such as bombs, aerial torpedoes, shells, rockets, etc., after they have left the airplane or the ground as the case may be, in order to correct for the initial sighting errors and other errors including drift errors due to variation of side winds at varying altitudes. Thus, in bombing a target on the ground from an airplane, initial errors present at the time of the release of the bomb are generally augmented by the variations of the bomb trajectory due to such things as wobbling of the bomb, variation in the wind direction and speed with changing altitude or change in the speed or direction of movement of a moving target.

It is also very desirable to effect automatic detonation of explosive missiles such as bombs, aerial torpedoes, shells, rockets, etc., when they arrive at the distance of closest approach to the target so that difiiculties commonly experienced in the use of time-delay fuses or the like may be avoided. Among these difficulties are the considerations of firing range, time required for loading, and other known factors which influence the computed time for the explosion calculated from the moment of discharge.

In accordance with the present invention, the detonation of the charge carried by the missile is caused by an arrangement which is activated by the mutual interaction of the missile and the target, and which is uniquely responsive to the arrival of the missile at its closest approach to the target.

In one embodiment of the present invention, the effect is obtained through the provision in the missile of means for projecting ultra high frequency electromagnetic energy toward the target, and for receiving a portion of said energy reflected from the target, said means comprising frequency responsive means for effecting the detonation of the missile when the beat frequency between the projected and the received energies reaches a predetermined value.

In another form of the present invention, the missile is provided with means for directly receiving ultra high frequency energy projected from a source removed from the missile and for receiving energy from said source after reflection thereof from the target, and frequency responsive means coupledto said receiving means for detonating the missile when the beat frequency between the directly received energy and the reflected energy reaches a predetermined value.

The principal object of the present invention is to provide novel apparatus for bombs and other explosive projectiles such as rocket missiles, aerial torpedoes, shells, rockets, etc., whereby said missiles are automatically detonated and caused to explode when said missiles arrive at substantially their nearest approach to a target.

Another object of the present invention is to provide an ultrahigh frequency transmitter adjacent the point at which the bomb or other missile is released, the missile being equipped with suitable ultra-high frequency radio receiving apparatus and means coupled to said apparatus for detonating the missile when the latter and a selected target are in a predetermined spatial relationship.

Another object of the invention lies in the provision of means for effecting automatic detonation of the missile when the same has reached the distance of closest approach to the target.

Still another object of the present invention is the provision of a missile with oscillating detector means for producing electromagnetic energy and for receiving such energy as reflected from the target, the said means serving to effect the detonation of the missile when any desired beat frequency is reached between the transmitted and received energy.

Other objects and advantages will become apparent from the specification, taken in connection with the accompanying drawings wherein the invention is embodied in concrete form.

In the drawings:

FIG. 1 is a scchematic view illustrating one use of the apparatus of the present invention.

FIG. 2 is a vertical part sectional view of a transmitter optical sighting and energy radiating means.

FIG. 3 is a longitudinal cross sectional view showing a missile equipped with flight control and automatic detonating means in accordance with the present invention.

FIG. 4 is a sectional view along 44 of FIG. 3; and

FIG. 5 is a wiring diagram of a somewhat modified structure.

Similar characters of reference are used in all of the above figures to indicate corresponding parts.

Referring now to FIG. 1, reference numeral 1 designates an airplane equipped with one form of the transmitter apparatus with which the missile of the present invention may be employed. This craft is adapted to carry an ultra-high frequency oscillator 2 as of the type disclosed in Patent No. 2,242,275, of R. H. Varian, dated May 20, 1941, for delivering to an aerial transmitter antenna assembly 3, ultra-high frequency carrier waves of the order of 10 cycles per second, such waves being subject to propagation in substantially straight lines and also having the property of penetrating fog, etc. and not being appreciably interfered with by uncontrollable natural phenomena such as radiation from the sun. The antenna assembly 3 is shown in detail in FIG. 2 and comprises a parabolic reflector 4 which has a diameter preferably twenty or more times the wavelength used, whereby this reflector has high resolving power and produces a highly directional beam of electromagnetic energy. A radiator element 3' is supported at the focus of the reflector 4. The reflector 4 and element 3 are shown as carried by the lower end of a telescope 5 that has its line of vision coaxial with that of the electromagnetic radiation beam shown diagrammatically at 27 in FIG. 1 and and projected from the antenna assembly 3. The telescope 5 is universally mounted as by means of a ball joint 6 so that this telescope and the connected transmitter antenna may be turned to any desired angle.

In the event of bombing through the overcast, the telescope 5 need merely be used as an angular shifting means for turning the antenna element 3' and reflector 4, the information used for then directing the beam being obtained from any suitable radio direction and range indicating system. The ultra-high frequency radio output of the transmitter antenna assembly 3 is adapted to be received by four antennae 7, 7', 8, 8' carried by a missile 9 illustrated in FIG. 3.

Antennae 7, 7' are spaced an appreciable distance apart as by placing these antennae on the outer edges of opposed fins 10. Similarly, the antennae 8, 8 (antenna 8 not shown) are spaced appreciably apart as by being located on the outer edges of fins 10' extending at right angles to the plane of fins 10 carrying antennae 7, 7

The form of the missile illustrated in FIG. 3 is generally similar to missiles in general use for bombing from aircraft. However, the stabilizing fins 10, 10' are shown extending radially outward from the cylindrical body of missile 9, whereas the conventional form of missile used for bombing comprises fins somewhat farther astern of the main body of the missile and of no greater radial extent than the cylindrical body of the bomb. Either the form shown in FIG. 3 or the conventional form of bombing missile is suitable for use with the present invention in the manner of installation shown in FIG. 3. The latter form-the conventional bomb--is readily adapted to be propelled from a cannon, if desired, in preference to the form of FIG. 3, which is shown with disproportionately extensive stabilizing fins for clarity of illustration of the invention.

In the form of missile shown in FIG. 3, or the conventional form in use as a bomb, the antennas 7, 7' 8, 8 may be mounted on the outer extremities of the stabilizing fins.

In the form of missile conventionally used for bombing, the smooth cylindrical surface wihch defines the maximum radial extent of the bomb, adapts the missile to be projected from a smooth bore cannon. Furthermore, similar missiles having substanitally cylindrical bodies and relatively small stabilizing fins are used as rocket projectiles, being discharged from tubes or guns used for directing the rocket missiles toward a target.

In FIG. 3 the antennae 7, 7' are shown as dipoles connected through concentric lines 11, 11 to suitable impedance matching transformers 12, 12' of the type disclosed in Patent No. 2,406,372, dated August 27, 1946, Hansen et al. which in turn supply the received energy to crystal detectors 13, 13 of the type disclosed in Patent No. 2,406,- 405, dated August 27, 1946, F. L. Salisbury. The detected outputs of crystal detectors 13, 13' are supplied to amplifiers 14, 14' the outputs of which are shown supplied through rate circuits 15, 15'. If desired, the rate circuits 15, 15' could be omitted. Inasmuch as the particular type of matching transformers 12, 12 or crystal detectors 13, 13' or rate circuits 15, 15' here employed form no part of the present invention, a fuller description of these components is not deemed necessary. Any conventional elements of these types may be used here. The outputs of the rate circuits 15, 15 are connected respectively to solenoids 16, 16' arranged for opposite actuation of armatures 19, 19' connected to a piston 17 of a balanced valve 18. The central portion of valve 18 is supplied with compressed air or carbon dioxide gas from a tank 20 through pipe 23. When carbon dioxide is used it may be carried in liquid form in tank 20. Valve 18 has two upper pipes 21 and 21 that have their outer portions extending radially within the cylindrical body of the missile 9 in opposite directions, the common axis of these portions of the pipes 21, 21' passing preferably through the center of gravity of the missile. The outer ends of the pipes 21, 21' project through the housing of the missile for delivering compressed air or carbon dioxide gas in opposite directions diametrically of the missile. The radial portions of pipes 21 and 21' lie in the vertical plane also containing the spaced antennae 7 and 7'.

The antennae 8 (and 8 are similarly connected to a receiver circuit, such as shown in FIG. 3, for controlling the operation of solenoids 22 and 22, shown in FIG. 4, the armatures of these solenoids being employed for operating the balanced valve 18' similar to valve 18, valve 18 controlling the flow of compressed air from the pipe 23 to two outwardly extending pipes 24 and 24' extending through the wall of the missile 9 for directing air or carbon dioxide blasts in diametrically opposite directions. The radial portions of pipes 24 and 24 lie in the plane of antennae 8, 8.

In use, preferably a suitable bomb sight is provided on the aircraft such as that disclosed in Patent No. 2,162,698, dated June 20, 1939, and is employed for releasing the missile 9 at the proper time and in the proper direction for hitting the target desired. After releasing the missile and before the same has reached its target the bombardier looks through the telescope 5 and observes the falling missile. To aid him in observing the missile, the same may be provided with a lamp 25, if desired. Inasmuch as the forward velocity of the missile decreases gradually after release thereof due to air friction the bombardier would ordinarily direct the pilot to reduce speed so that the aircraft flies over the target at about the same time as the predicted time for the missile to strike the same. This change in speed of the airplane makes the same an extremely difficult target to hit from a point such as the ship 26, shown in FIG. 1, inasmuch as all predictions are based upon the craft maintaining a fixed speed.

It is preferable for the bombardier to keep the target or point in sight through the telescope 5 as the missile falls. As the missile approaches the target, the latter moves into the field of vision of the bombardier looking down through the telescope 5 although the target is probably not in the central line of sight of the telescope at this time. If the oscillator 2 is now turned on producing the pencil beam 27 of ultra-high frequency electromagnetic radiation the field intensity of any cross section of which is greatest at the center 27' of the beam and tapers off in substantially the fashion shown toward the side edges thereof, the missile will ordinarily line itself up with the center 27' of the beam. Assuming that the missile is not initially lined up with the center of the beam then due to the varying field intensity of the beam across its cross section one of the antennae 7 or 7', for example, will receive more energy than the other, so that the output of amplifier 14, for example, will be made greater than that of amplifier 14, whereby solenoid 16 is energized to a greater extent than solenoid 16 so that the balanced valve 17 is moved to uncover pipe 21 thereby causing tank 20 to discharge compressed air or gas through valve 18 and pipe 21 and elfecting a movement of the bomb toward the center of the radiating beam. Similarly, if antenna 8, for example, should receive more energy than antenna 8' it would act to shift the bomb transversely in the plane of these antennae to bring the bomb into the central axis 27 of the radiating beam corresponding to the center of the line of sight of the telescope 5. As the missile is about to strike the target the bombardier gradually shifts the telescope 5 angularly so as to bring his line of sight and hence the missile into the direct line of the target so that the latter will be hit as desired.

It will be noted that as long as the missile is lined up with the center 27' of the radiating electromagnetic beam, the antennae 7, 7 and 8, 8' will receive equal intensity of signal so that the balanced valves 18, 18' will be held in their neutral positions so that the outputs of the various amplifiers will be equal. Should the missile commence to move out of the center of the beam the antennae will receive signals of unequal strength resulting in the operation of the servo-mechanism and the movement of the missile transversely back into the center of the radiating beam. Owing to the high pressure of the air or gas within the tank and to the fact that the period of time of flight of the bomb is short, the flow of air or gas through pipes 21, 21' and 24, 24' is quite rapid so that the reaction force of the jets issuing from these pipes is large, thereby resulting in an immediate response of the missile to any deviation of the same from the path of the beam effecting a rapid return of the missile to the beam. Should the bombardier move his telescope 5 angularly too rapidly so as to lose the missile he can always turn the same back and pick the missile up again.

The flight controlled missile and radio energy transmitting apparatus employed therewith has thus far been described for the purpose of providing a vehicle and control for the automatic detonating device presently to be described. It is to be understood, however, that this particular type of missile and/or radio energy transmitting apparatus has been selected for this purpose merely as an illustrative example and therefore should not be regarded as a limitation on or restriction of the application or use of the automatic detonator. Other types of transmitting apparatus producing, for example, I3. plurality of ultra high frequency electromagnetic energy beams instead of the single beam, heretofore described, may be employed with a missile carrying a different type of receiving apparatus adapted to respond to the plurality of beams for the purpose of following the path determined thereby. This and other forms of missiles and transmitting systems corresponding thereto are described in the above-mentioned parent application Serial No. 401,474 and may be utilized as the vehicle for the present invention in place of the radio energy transmitting apparatus and flight controlled missile hereinabove described.

In the form of the invention shown in FIG. 3 the missile 9 is provided with means for effecting the detonation thereof when the missile has reached a predetermined position with respect to the target. In this figure an ultra high frequency oscillating detector 30, which in the type disclosed in No. 2,406,370 in which the present applicant is a joint patentee, comprises a velocity modulation electronic device having a pair of electronbeam-coupled cavity resonators, means for radiating and receiving electromagnetic energy, and detector means for detecting and beating energy returned to the device by reflection of the radiated energy, from a target, with a part of the energy radiated, is employed herein having a connected antenna 32 which serves to transmit the output of this oscillating detector and to receive waves reflected from the target. Owing to the Doppler effect, the beat frequency between the output of the oscillating detector and the frequency received thereby is proportional to the relative velocities between the target and the projectile and since the relative velocity at closest approach is zero the Doppler frequency at such point will drop to zero. By having an audio amplifier 34, as of the type described in Termans Radio Engineering, published by McGraw-Hill Book Company, second edition, page 210, connected to the output of oscillating detector 30, tuned to a desired frequency the missile may be made to detonate at any desired position with respect to the target as the same advances toward the target. The output of amplifier 34 is fed through a wire 36 which serves to detonate the charge 38 at the desired point.

In the form of the invention shown in FIG. 5 the missile is not provided with a local oscillating detector but instead is provided with an ultra high frequency detector 40 fed from the antenna 42 the output of which detector is fed through the audio amplifier 44 to a series of filters 46 to 56 which filters have progressively higher band pass frequencies. The outputs of these filters are supplied to rectifiers 58 to 68, respectively, the output of which rectifiers in turn are adapted to operate relays 70 to 80, respectively. In operation, if the missile approaches a rapidly moving target the Doppler frequency produced by receipt by antenna 42 of the direct radiation from the transmitter 2 in FIG. 1 and that received by reflection from the target will decrease as the missile approaches the target so that a point is reached for a rapidly approaching target where filter 56 will pass current, thereby operating relay and preparing a circuit for relay 74. As the missile approaches closer to the target filter 50 will finally pass current energizing relay 74 and effecting the detonation of the charge 82. On the other hand, if the target is not as rapidly approaching, it is quite possible that the Doppler frequency will be lower than that passed by filter 56 so that the lower band pass filter 54 will energize relay 78 thereby preparing a circuit for relay 72 which, when closed by the passage of current by filter 48, i.e., when the missile is in the proximity of the target, then the charge 82 will be detonated. The operation of filters 52 and 46 is similar and applicable to even slower approaching targets or to receding targets.

It will be noted that since no oscillator is employed on the projectile, the Doppler frequency obtaining, which is a beat between directly received and reflected waves, does not reach zero, at closest approach and hence the necessity for the use of filters as shown in FIG. 5

It will be understood that the missile launching apparatus herein illustrated as the airplane 1 is merely exemplary and indicative of one type of apparatus which may be so employed. If desired, the missile may be launched from the ground as by a gun, catapult, rocket tube, or any other type of missile launching apparatus or platform.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In apparatus of the character described, a missile adapted to be propelled toward a target, means for directing electromagnetic radiation at said missile and from the target, said missile having a receiver for receiving the direct radiation from said radiating means and for receiving radiation reflected from the target, a normally open detonation control circuit in said missile, and frequency selective means controlled from said receiver for effecting the closing of said detonation circuit when a predetermined heterodyne frequency is produced in said receiver by said direct reception and said reflected reception.

2. A projectile as defined in claim 1 wherein said frequency selective means comprises a plurality of filters of progressively differing band pass frequencies and relays controlled from said filters, said detonation circuit comprising a connection between a relay operated at a certain frequency with a relay operating at a higher frequency.

References Cited by the Examiner UNITED STATES PATENTS 1,386,459 8/1921 Dawson et al. 89--41 1,769,203 7/ 1930 Buckley 1029 X 1,862,918 6/1932 Barnes 89-41 2,022,517 11/ 1935 Patterson.

2,066,156 12/1936 Mufliy 177-352 2,137,598 11/1938 Vos 10270.2

(Other references on following page) UNITED 7 STATES PATENTS Koch 250-2 Ferrell 10270.2

Crooke 89-41 FOREIGN PATENTS Austria. France. Great Britain. Great Britain.

8 524,876 8/ 1940 Great Britain. 339,479 4/1936 Italy.

91,592 2/1938 Sweden.

BENJAMI'N A. BORC'I-IELT, Primary Examiner.

0 H. L. MARTIN, L. H. MEYERS, W. C. ROCH,

1 Assistant Examiners.

Claims (1)

1. IN APPARATUS OF THE CHARACTER DESCRIBED, A MISSILE ADAPTED TO BE PROPELLED TOWARD A TARGET, MEANS FOR DIRECTING ELECTROMAGNETIC RADIATION AT SAID MISSILE AND FROM THE TARGET, SAID MISSILE HAVING A RECEIVER FOR RECEIVING THE DIRECT RADIATION FROM SAID RADIATING MEANS AND FOR RECEIVING RADIATION REFLECTED FROM THE TARGET, A NORMALLY OPEN DETONATION CONTROL CIRCUIT IN SAID MISSILE, AND FREQUENCY SELECTIVE MEANS CONTROLLED FROM SAID RECEIVER FOR EFFECTING THE CLOSING OF SAID DETONATION CIRCUIT WHEN A PREDETERMINED HETERODYNE FREQUENCY IS PRODUCED IN SAID RECEIVER BY SAID DIRECT RECEPTION AND SAID REFLECTED RECEPTION.

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