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Publication numberUS2660794 A
Publication typeGrant
Publication dateDec 1, 1953
Filing dateSep 12, 1942
Priority dateSep 12, 1942
Publication numberUS 2660794 A, US 2660794A, US-A-2660794, US2660794 A, US2660794A
InventorsGoertz Raymond C, Hull Harvard L
Original AssigneeSperry Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Computing gun sight
US 2660794 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Dec. 1, 1953 c. GOERTZ HAL 2,660,794

COMPUTING GUN SIGHT Filed Sept. 12, 1942 3 ShGGt-She6t l Fl G. 2 I4 24 GUN CONTROL SERVO MPLIFIER CONTROL AMI? 16 7 FIGS J I41 I24 222 H 4.}l



COMPUTING GUN SIGHT Filed Sept. 12, 1942 3 Sheets-Sheet 2 MOTION or TAJGET TIME 0F Fl/Gl/i' 04M 7 mil:

TORQUE AMPLIFIER Patented Dec. 1, 1953 UNITED r STTETS '3 Claims. 3

Th present irrvention'is related to the art including computing gun'sights and gun turrets.

The present invent-ion is especially concerned =wi'thc'omputing g-un sights of the type in which 't-he' 'si'ght is carried by or moved in synchronism with" the gun or turret and is onset or disturbed with'respect to the gun by the amount necessary to give the proper lead angle of the gun with respect to the present orientation of the target defined by the line of sight of the sighting mechanism; to properly directa projectile to the target. Such a sighting-device is shown in copending application Serial No. 353,382, forComputing Aircraft Gun Sight, filed September 26, 1946, in the names-' ofC. Gofiolschuh and O. Vielehr, now Patent 2,396,701, g'ranted March 19, 19%. oomputing'gun sight'of' this prior application is The intended for directmanualoperation in an aircraft. "The present invention constitutes an improvement of-and a simplification of the gun sightof the prior application, including a manually controlled power means for rotating theguns and a simplifiedlead computing mechanism suit able for use eithe-r'on aircraft or on the ground,

against any moving targets.

Disturbedgun sights of the present type are subject to a type of instability which renders their efficient operation "very 'difiicult. This instability may be seen from the consideration that,

if the line of sight should be lagging behind the target, and the gunner desires to move the line'of sightup onto'the target, his naturalactionis' to increase the'velocity of tracking of the gun and sight. In so'doing, thelead angle also increases,

since it has one component (predictiom proportionahto the angular velo'city'of the guns, and ther etor tends-to driv'e -the sight baclvwith 5 respectto. the gun and away'from the target. This constitutes an unnatural response-to the" natural tendency of the operator, and results in confusion and difliculty in a'curately' 'maintaining t'he line of-sightintrackwith the target.

"This objection" to the disturbed sight is-;overcome by the present invention,- and-a further advantage in-simplified tracking is obtained by pro 'vidi-ng a- 'contr'ol-of the sight-which at the-first instant in response to a change in velocity, moves the sightiorwarch namely; in the direction of the target; rather than reversely; as has formerly been the case. This temporaryforward motion is then-wiped-out and reversed to provide therequire'd lead'angie aftera time delay sufiicient to prevent the unstable operation'referredto above. In this manner-an aided tracking typeof control of thesight'is obtained; whi'chhasbeen'iound to be advantageous in facilitating accuratetracking with a moving target.

In addition,- the present invention provides the furthenfeature thatthe orientation of the sight is rendered independent-of'the computing apparatus-and is controlled solely-hy the manual control-cf the operator,"whereby" the effectof change in the lead an'gle does *not'impai'r the ease-and effectiveness'oi control of the'track'ing.

Accordingly; it is an object of the -present' 'invent-ion to provide improved computing -gun sights'of the fdisturbednighfi type, eliminating the" unstable operation of prior art systems;

It is a further object of the presentinvention to provide improveddisturbedgurr'sights in'v'vhich the sight isinsta-ntaneously actuated in a-"direction to follow the target upon a change of the position'of a manual control, and is thereafter delaya-bly mov'ed in theopposite "direction to introdnce the reqrrired lead" angle betweemthe sight and the gun.

It isa still'fur'ther objector the present invention-to'provide improved disturbed gun sights incorporating'anaided'tracking type of control of 'the sight.

It is-another object of the present invention to "provi'de improved"disturbewgun -sights in which -the"-"eoi'itrot of 't-l'ie -oi'iefltation' o'fthe-line of sight is made independentof the lead angle, *whereby ease oftracking is greatly improved:

Itis= still another object "of thepresent' inventionto provide improveddisturbed-gun sights including means for delayably offsetting the sight by the required lead angle to prevent unstable operationythe amount-of delaybeing adjusted in accordance with the projectile time of flight" to provide improved *operation'both' with dist'a'ntand with close-in targets.

It 'is'a' further object of the' present invention to "provide "an electrically operated disturbed gun sight incorporating at least some" "of the advantages' described above.

It is still another object "of the present invention toprovidea simplifiedmec'hanical construction for a disturbed gun'sight also including these advantages."

Other objects and: advantages will become apparent-from the specification, taken in connection with' "the accompanyingi'drawings wherein the'inventionis embodied in concrete form.

'In the'drawings;

"Fig. 1' shows a schematic. perspective view of a representative'gun'turret, such as maybe used with'the'present invention.

*Figi? showsa schematic circuit diagram of an electrical embodiment of the control for a disturbed gun sight according to the present inven tion, showing the control along one coordinate.

Fig. 3 shows a diagrammatic view of a mechanical embodiment of the present invention for controlling the device of Fig. 1.

Fig. 4 shows a schematic diagram of a complete mechanical embodiment of the present invention, including the features and advantages described above, and V Fig. 5 shows an improved form of the circuit of Fig, 2.

Fig. 1 shows a schematic perspective representation of one form of gun control and sight. In this case, the guns I I are mounted on a platform I2 for rotation about a suitable axis, in this case illustrated as being a vertical axis, whereby the guns I I may be rotated in azimuth. Also carried by platform I2 is the sighting device, illustrated schematically as being a telescope I3, which may be any type of device adapted to define a line of sight to a distant target. I

By a sighting device in the present case is meant any device defining an axis and capable of indicating or determining when this axis is oriented toward a target, and may include radio, infra-red, photoelectric or other devices as well as the usual optical telescope or sight.

Platform I2 is adapted to be rotated in azimuth by means of a suitable servo device I I which drives a inion I6 engaging an internal fixed ring gear I'I, whereby the platform 32 is caused to rotate by the interaction of pinion I 6 and fixed internal gear I'!. Servo I 4 is controlled from a manual control member I8 by means of suitable control mechanism, indicated by the control box I9.

Manual control member I3 and its associated circuit are preferablyof the type disclosed in Figs. 12A and 12B of copending application Serial No. 428,036 for Positional Control System, filed January 24, 1942, in the names of H. L. Hull, R. C. Goertz and W. C. Hartman, now Patent No. 2,526,665, or in Figs. 2-4 of copending application Serial No. 403,618 for Handle Control Systern, filed July 23, 1941, in the names of H. L. Hull, W. C. Hartman and R. C. Goertz, now Patent 2,414,102, granted January 14, 1947, and are adapted to produce an electrical voltage corresponding in sense and magnitude to the sense and magnitude of displacement of control member I8. As shown in copending application Serial No. 428,030 in its simplest form, the means employed for converting the displacement of control handle I8 into a corresponding electrical voltage signal may comprise merely a resistive potentiometer winding having its opposite terminals connected to a constant source of alternating or direct potential, and having a movable contact arm actuated by control handle la. The voltage between the contact arm and the midpoint of the resistive winding then provides the required electrical control signal.

Fig. 2 shows one form of control circuit which may, for example, be included in control box I9 in Fig. 1, operative in response to the control signal produced by the control member I 8 to orient the guns I I. Thus, the control signal derived from the manipulation of control handle I8 is connected to input terminals 2I, and is thereby impressed across resistor 22; Resistor 22 is connected in series with a resistor 23, whose function will be described below, and the resultant series voltage across these two resistors is impressed upon the input of any suitable conventional type of amplifier 24. Amplifier 24 is preferably chosen to have a large amplification, whereby it may produce full output voltage for a very small input voltage. The output of amplifier 24 then actuates a suitable servo device It. Servo I4 may be of the well-known Vickers variable-speed hydraulic transmission type, in which a predetermined input control signal voltage produces a corresponding and preferably proportional rate of turn of its output member 28 connected to pinion l6, shown in Fig. 1. If desired, any of the servo devices shown in Figs. IDA-10D of application Serial No. 428,030 may be used here.

Connected to be rotated simultaneously with platform I2 is a generator as, shown for example as driven from a pinion 3I journaled in platform I2 and connected to generator 29 by any suitable mechanical means, indicated at 32. Generator 29 is preferably of the type which produces an output voltage directly proportional to the speed at which it is driven, and this voltage is impressed upon resistor 23 in series with condenser 33 This voltage is of the same type (alternating or unidirectional) as the signal voltage impressed across terminals 2i. Preferably, generator 29 is of the permanent magnet direct current type, and the control signal is unidirectional or is converted suitably into a unidirectional voltage across resistor 23.

Neglecting for the moment the effect of condenser 33, it will be seen that the control signal voltage impressed on resistor 22 will serve to actuate servo I i, and thereby sets up a rate of turn of platform I 2. This rotation of platform I2 produces a voltage by means of generator 29, which is impressed upon resistor 23 to oppose the voltage across resistor 22. By making amplifier 24 sensitive and responsive to small values of in put voltage, an equilibrium condition will be reached in which the voltage input to amplifier 24 is just that necessary to produce a rotation of platform I2 and generator 29 such as to produce a voltage across resistor 23 diifering from that across resistor 22 only by the small amount necessary to actuate amplifier 24 to maintain operation of the rest of the system. Since the voltage output of generator 29 is proportional to its speed and that of platform I2 and guns II, it will be seen that in this way the control signal voltage impressed on terminals 2I, and therefore, with condenser 33 omitted, the deflection of control member is, will be substantially proportional to the angular velocity of the guns I I and that, in effect, a rate type of control is provided, as described more in detail in application Serial No. 403,618, in which a predetermined deflection of manual control member It produces a corresponding angular velocity of guns II and platform I2.

Condenser 33 serves to provide a type of integrating or smoothing control. Thus, if the guns II and platform I2 are being rotated at a constant angular velocity, a constant voltage will be generated by generator 29 and will charge condenser 33 substantially up to this voltage. During the time condenser 33 is charging to full voltage, the Voltage across resistor 23 will correspondingly decrease since the sum of the condenser voltage and the resistor voltage must continuously be equal to the voltage produced by generator 29, which generated voltage is constant if the platform has a constant angular velocity of rotation. The deflection of the control handle I8 necessary to maintain this constant angular velocityzof platformzelfl will continuouslyidecrcase. sincerin nrderg-tormaintain -;aa:constantaangidar velocityiof'zplatiormrfi: the displacement.:nf:;-controhrhandie -:Rl '81 :inust be .alwaysrjnsmsufficientito :produceiacontrol signahzoltage=a-crossrresistorz22 w hichzcdifiers *f romzthe .iyoltageraorosscresistor r23 oy the smalhcionstant'amount necessary tozmain- .tainathis uangular :velo'city. i'Ihe-areqnired Edis- ;placement; will theneforeradecrease asoondenser 33 vchargesstand the :yoltageraacross resistors-r23 decreases. =.a'Ihus,"-aftertabringing the;pl-atiormaand guns up :to' the desired angularl'veloeityiithe icontrol {member .18 zmay :be agraduai ly returned: to: its neutrah position VZith0llb'-.rchangingljhe angular velocitynf thetp-latform. this way, vcondenser 33 operates i110 .cause' the platform :l2 and guns I i-tohcontinuerto rotateat the same velocity: even aftertamanua'l .controiler 18 is 1 returned ato its neutral position-.r 2

: Sighting idevice I 3 is; a'lsoaoarried' by platform '12, ibutadiustablewith:respect thereto by means ,of servo 412, so-that if theimanual controller 1 8 is adjustedfso that-:theJimeof sight definedeby sighting device I3 is tracking with :a tar'getyit Will the .clear that the guns. I l are movingat the same angular velocity as that of the target rela ztiveito theigun position. 1;

If aij-projectile isifire'drsby the-"gun, itwill take -a predetermined :time interval, known itime ot'fii'ghtfibefore reaching the-barge ingzizthis time of: fiight the: target will have advanced' it's position-:by an amount-roughly equal to: the angularrveloeity of the itarget relati-ve 'to the gun positionltimes :the timezofflight-which is termedl the predictioni lead' angled Accordingly iin order to permit" the gun to effectively direct the proj ectile; the orientation of 1 thelgun must be advanced with 'respect to the' orientation Lof .th'eitarget by :anamount corresponding' -to this leada angle; In -"the present:systempthis is don'e by retarding theisig-htingdevice "13 *relative to --platfiorm' F2 on which itai'scarried and -to the guns 1-! thus producin c "disturbed gun sights "For 'thiscpurpose; it'willebe notedthafi' the' v'olt age' produced by igenerator" 29 is proportional to the angular velocity of the platform- 1laifid gdns 'I-l and hence;when. the 'sighting"device 113 is tracking with the 1 target, will also be sabstam tially -proportionalr to the angu lar =veloeity of= the target:

' To' multiplythis voltage by the time assigns, I

a potentiometer-35 is connected-across the teriminals of generator It --\vill --be=-c1ea-r=tnat the vo1tage der-i'ved between" the variable arm Sfi of potentiometer- 34' and one ofits fixed terminals will be proportional to the""defl'eetiori- =of-a1m-36 from its "end position 'and will also be propors tionalto the voltage-impressed across the entire potentiometer "-34, that-is, will" be proportional to thevoltage -of generator 29, which hasalready been shown to be 'proportional to theflg-un or target angular --ve1oc-ity 1 during proper tracking conditioxis- Thereioregby suitably 'ad'justing arm '36, as by means of a-knobfl, proportionally to time of flight, the 'outp u-t voltage irom rmtenti ometer- 3 1 may be taken -as proportional-tothe product of target angularvelocity and-*the 'time of flight;- sinoe time 'of flight is'approximately a function only ojtarget range;knob fil-inayhe provided' with a suitable-scalecalibrated di'rectly :magnitndes, qthezsight :13 :may be angular-1y displaced from thezorienta-tion :of the gunsrljlaby exactly theproperlead angle iowprovidezso-oakled fn ediction-ecorrection: or prediction leadeangle iorrthegunsgtoxallowdor'the motionzobthe target ;relatlye;tothe;gnns.ii-" r alt will-c bB'J'SEEIl-thtt if gunsl lv aremovingfifor exaample, :clockwiseginrFigml; sight at3-';mustf'be displacedjnzacounterclockwise sensexvithmespeet r110 platform [2. a If thesight '13 is-tracki-ng behind thentarget; and thel'gunner; attempts to accelerate theasight' to "-iget "on :the. target; "it will .;be; seen that: any: .increa'sez'in gun and :platform :izelocifiy Will produce a displacement?ofxsight :13 itending to increase the :lag betvzeenvsightsand"targetpand the-more the gun velocity:is:increased;theigreater lag :isproduced, although. the gunner :is'attemptingto decrease theilag; Thisaction islcharacter istic et all :disturbedl'sig-hts, and renders tracinihg with the target yer yszunnatural tand'xiiffioult, thus preventing-optimum:utility:.ofa the devicem To overcomethis defectgacondenser s46 arid'sa resistor 41 are connected across-'thehinputiters minals 121 supplied a with: the controlz signalx.and the voltage across resistor fl 'l isfinserted in'sseries :across s the voltage :output: .of the: rtime of-flight potentiometer-M and-is therefore addedithereto. The values .of condensersllfiaand resistorztlsa-re chosen: such :that' sthese elements form "ca differentiating :circuit i-n a: manner :well s-known Ii-n thexart, whereby thesnvoltage derived across =resistoriAfl corresponds-"to the rate of change of the control signal impressed on terminals 21. 7

:By. adding: this voltage to the lead 'angle. :volt- -34; the sightalz-a is initially actuated'in .suchiaa mannernasto follow theztarget, rather than in the; :opposite zsenseiuas would otherwise' be ime ease-e c Y L This:actionservesto ovencomethetracking 'lag andthe sight catchesiupirto'theLtarget. ;At this instantg-iiof courseuthefoorrect 1ead:.ang1e isrnot present, :hutthis is immaterial :since firingktzis 'done only while accurately "tracking the targets: In this way',:the tsight:respondsads the o zzeratorwould "intuitively expect, "and: not oppositelm and thong-aerator is enabledito getiorr the ta'rget-much morequickly to 'placeathe sight theiproper tracking condition.

: .711; will be seen: that the rate voltage derived from resistor 4 1' wfill die out as the control-signal persistspand-that after a short time the-actual lead angle between sight 13 and-guns II will again becbme ---proportional to the lead angle voltage,- a s is: required, whereupon accurate-fire can be obtained once more.-' In thisava-yastable and easi lyoperated disturbed gunsight system is provided; eliminating the instability charactcri-stic-of'prior'art devices.

x Tli-diffrntiatingcircuit 46, 47- alsoproduces 7 a type of aided tracking control for the sight. As is known, in an aided tracking control, the controlled device is actuated so that its displacement from a predetermined neutral position is related to a constant displacement of the controlling member by a relation of the form 0: knp +k2q2'b where k1 and R2 are proportionality constants and t is the time the control displacement persists.

In the present case, the motion of the guns and platform carrying the sight produces the second term of the right member of the abov equation, while the differentiating circuit 4%, 4? produces the first term, at least in transient fashion, during getting on the target, when aided tracking control is most useful and desirable.

It is to be noted that the device thus far described serves to supply only the prediction lead angle. Other lead angle components may also be provided by inserting voltages proportional thereto in series with the input to amplifier 4!.

The system of Figs. 1 and 2 has been described with respect to motion about one axis only, illustrated as being the azimuth axis. It is to be understood that preferably the guns 1 l and sight 13 are made rotatable also about a second axis, such as an elevation axis perpendicular to the azimuth axis, under the control of a suitable manual control member, which may be member 18, displaced about a second independent axis, as is shown below in Fig. 4. A similar control between the elevational motions of the sighting device 13 and guns ll may be provided for motion about the elevation axis, as shown in Fig. 4, whereby the gun sight of th invention may be utilized with targets moving in three dimensions, such as aircraft.

The system of Fig. 2 still suffers the disadvantage that the gunner, in order to maintain the sight in track with the target, must actuate the sight (by means of his control of the guns and platform l2) to compensate for changes in lead angle. It is preferable, from th standpoint of simple and effective tracking, that the operator be able to manipulate the sight without adjusting for changes in lead angle. This is done in Fig. 3, which shows a modified type of control system similar in principle to that of Figs. 1 and 2, but entirely mechanical in operation. Here control handle I8 is coupled to arm 50 and displaces the ball carriage 5| of a variable speed drive 52, whose drive disc 53 is rotated at constant speed from a constant speed motor 54. In'this way, the output cylinder 56 of variable speed drive 52 is rotated at an angular velocity proportional to the displacement of control l8. This rotation of cylinder 56 is led through suitable gearing 5'! and a differential 58 to rotate an output shaft 59 which is connected by way of gearing 6!, shaft 62, gearing 63, and shaft 64 to a torque amplifier 66 whose output 6'! drives pinion IS with respect to fixed rin gear I T in the same manner as in Fig. 1. Torque amplifier 58 may be of any suitable type adapted to provide a high torque output from a relatively small torquev in put derived from shaft 64. Such amplifiers are well known in the art and are believed to require no further description here. One form of such torque amplifier is the well known Vickers hydraulic variable speed drive.

In this manner, displacement of manual con trol l8 sets up a corresponding angular velocity of platform [2 which carries all of the elements shown in Fig. 3, except the fixed ring gear IT,

in a manner similar to that shown in Fig. l,

and hence provides a rate control of sight l3.

At the sametime, the displacement of manual control I8 rotates a lever 68 about a pivot 69. Lever 68 is connected through a further linkage H, 12 to the sight I3 and thereby displaces the line of sight M, corresponding to the optical axis of telescope 13 in Fig. 1, by a proportional amount and in' the same sense as the desired rotation of platform I2, as to a position 14 relative to the gun orientation which is along 14. This action therefore corresponds to the effect of condenser 46 and resistor 41 described in Fig. 2, since the sight I3 is thus initially displaced proportionally to the angular velocity of platform l2, and provides a resultant aided tracking control of sight 13, which has been recognized as a desirable type of control for efficient tracking.

At the same time, displacement of control member l8 moves another lever 16 about a pivot 11, which motion is transferred proportionately through a link 78, link 19 pivoted at 8i, link 82, and lever 83 pivoted about pivot 84, to proportionately displace ball carriage 86 of a second variable speed drive 81 also actuated from motor 54.

The rotation of output cylinder 88 of variable speed drive 91 rotates a shaft 91 carrying oppositely threaded screws 92 and 93 cooperating with respective traveling nuts 94 and 95, upon which are mounted the pivots 8| and 69 described above. Thus, the rotation of shaft 91 serves to displace pivot 8|, whereby lever I9- pivots about the new position of its pivot and returns the ball carriage 86 to its neutral or centralized position to stop the. rotation of shaft 9|, which will then have rotated through an angle proportional to the deflection of member l8.

At the same time, rotation of shaft 9| operates to move the traveling nut 95 carrying pivot 69, whereby lever 68 pivots about its pivot 10 and turns the sight I3 oppositely to its original motion. The angular displacement of shaft 9|, and hence the angular displacement of sight l3 thus produced, will be proportional to the displacement of manual control l8 and accordingly will be proportional to the angular velocity of platform I2, which will be equal to the angular velocity of the target during proper tracking.

It will be seen that this angular displacement of sight l3 and shaft 9| will depend upon the position of the pivot 11 about which lever 16 rotates. This pivot is made adjustable, as by means of a time-of-fiight cam 96 and a slide 91 actuated by a range knob 98, and is set in accordance with the time of flight of the projectile, determined in the same manner as with respect to Figs. 1 and 2, from a suitable range finder. By adjusting pivot 11 in accordance with the time of flight, the angle through which sight I3 is turned by shaft 9| is made proportional to the time of-flight plus a constant. Since the original deflection of sight ii! in the direction of motion of the guns was proportional to the angular velocity of the guns as determined by the angular displacement of control r8, this constant is chosen to be of such value that the resultant position of sight l3 will be displaced from the orientation of the guns by an amount equal to the desired prediction lead angle, or to the angular velocity of the guns times the time of flight, producing the same type of operation as in Figs. i and 2.

The motion of output cylinder 88 of variable speed drive 81 is also additively coupled to that asses-94 of; cylinder 5.8? by -way: ofigearingfiil and; difierem tia1158z Irrthis wa'y the-input to: torque amplifier: fifiijandthe platform ,IZ'i are add-itionally displacedi by aJ-com-pon'ent corresponding tothe Epredictionr Iead'angIe; 5

- -Since;the sight; I-3 is displaced relative-rte. platform. I 2 andguns- I I bywthe same amount.- as: their "guns and: platform f are I oppositely dislplacedz with-respect to: theita-rget; it: wiliihe-seen that sight. It has no;- motionzrelatiice-toethe target: dueieto the: 3617101121 of Wariabl'ev speed? rdrilver- 8-1;; whichitherefore setsin the proper'lead anglezwiths-x out; infamyway"v impairingzthe'i ease: of: tracking..- Imothen words, thea'gunner needznot compensate for .theisleadzangle; as, he must-din Fig. 2;.

- It. will bexseen thairvariable speedrlrive Bifacts. to initially delay the control; ofnsight I-3=1byather prnperfleadjangle, rsotithat easieriandis-tablatracking:;is possihle; This; delayis" controlledtby'sthe settling time? of: drive 81;? which is 'itheirtim'ei itgztakesi. to resume ar'stable posit-ion: after being displaced, and. depend-s on: the. speed; off motor" Etemd :the'; amount;thevballtcarriage lfifiiiscinitially displaced, which; latter. in.- turn'z 'depends= onus the; distance [advantage .ofzthe lever system 83 ;'18'2;;etcir 'I-his;;:set.tling time, inrth'eidevice: dffFigi: 3;:- is; selected-s to; have a; value: large enoughi toi uprovide stable traokingbyzsight -I:3;"andfshort=enough' to: obtainquick settings OffthE sight and guns to the'properrfiringpositions; I 1

It: williberclearkliere ialso'sthatz arsimilarrc'ontrol: maybeg-providediformotion abouta second axis" perpendicular. to the-axis-of rotation of-ssight; I3 and the guns; to' provide. three-dimensional con trol. I

-To yide control-icompensaitioni forthe'lead' angle niFig; 2; this:cir?cuitzrnaybe modified in: the-:manner: showrrin 5; by the -additiomof: agenerator-"45 driven fromithe'fis'ight servo 4 25syn:-- chrbnouslyz withe-sighti I 32- Generaton 45 ='ispref erabl-y of: the sameitype' asiigeneraftor 2'9',iand:prot-- dizcesaa voltage output =prop'ortiona1 to: the speed atawhichzitsiszdriven; whichwill therefore be proportional'a to the ratelofi change of'ithe prediction:

lead angle. 1 Thisipredictionirate voltage is' in' 5 sertedz in series: with; the :otheflvoltag input" tocontrol amplifier 241 As wa's seen zz-ithe speed 50f i-th'e 5 guns obtainedfifromr g'urrservo I is proportional'totm input yol-tageeiierivds'across resistor. '2 21 In1Fi'g. 5,:however, the: 'gun rate willa beinroportional" to the sum; of i the ivoltagei across resistor 2-2; and theivoltage derive'cl' from sgenergator}; 45: Aceordin'glm the: gun -torientation:-de-'- rived -byithetdeviceuof Rig; 5.-in respons'e."150:3;v change in displacement of't'controli I8; willibe-ad' vaneed'i from? the; corresponding"orientationofi' th8.'l1lfllifli Fig.-. 2-: by "an? amount; equal-"to; thee 'change-ain the dead tang-1e; so;thatwthefisightt and;

from potentiometer S it-resistor and'potentiomiffio" etertfi-gdescribed"inFig:2.1

I Figs; 4 shows L a :modificatiori: Of! the =-device:;of: i :3';inchrding:lcontrohalonggbotlr eleyationgandj azimuth coordinates and; incorporating i seyeraL improvements.{ Itrv will ?be; noted that. thei'devioefla;

1 i bfli-tyfofz'operation wand easeof. tracking. s:-

dependenti faxes; i corresponding-to L axis'varrd'ithaazimuth iaxis 'of rotatioli ofwtlf g'un I isr-desiraiblethataishort'rsettling'tinre be pr'vided in: orderrto? enable lithe gunner tc' quickly get 'into the accurate firing-.1" conditions E01 longerranges.andelongen times oft flightpailonger set tling tiInedsi desirable to pro'vide improVed s'tafeature is alsb'iiicorpbrate'ddn the device of Fig Referringitosthisi figure, the sight I3 is shown: as -'constituting'xa mirror "I (H I pivoted-1 about an: axis 5 I 02. preferably horizontally *di's'posedi and parallelitb theselevation trunnions of the gun: ands-eo'operating 'withra secon'dmirror I 03 1'aifioted about. an: axis": "I or: disposed along the axis or the gun. A; suitable: source aof light; indicated "sche-' matically" asa a :lamp bulle I06; p'ro'j'cts us -1am: rays-1through-:ascreeni or:' n1asking merxfber: I 81 havingsa; suitable-I'reticl'e 'l I18? fofmed 'thereofi; so that therimage ll-II ofr t'his: reticl' is -refleeted from; mirror I03 nth-mirror 'I 0 I, and-- tliereby intb the"'eye' 'I09;-tof1=the gunner;= Mirror-'- BI thiS DIane. Thisum'a'it be? termed? motion in: gun

slant gplanei azimuth; Rotation of: mirror "I III will cause-5thisi reticletimag I Fl 0 to :aph'ean tonrove perpendicular: tor-axis: I-02;: producing IIIUl'ii'Oh'E'Df? xelevation; 'As will b 'seerii.

the diner of sig mirrorsrrl III antf -I 03*Ear angularly 'displaoed in accordaince' rwith the? elevation and +s1an'tiplane azinruthiicomponentsiof 'i'thz -le'adi angleerequired c for proper operation, and therefore 'thei op'ticali system; I 3-;is'1 operatedii'n azsiriiilar' fashionwt'o' that of zEigsizian'd' 3, :hav ing it si-ilinei-ofisight offstor: di'sturbed'irom the gun orientation by the amount and-Lim the direction ofzrthe rres'ultant" lead "angle Irrzoperation; the? gunnermrill actuate theman ual controller-E I8%toi maintain 'the target central 1,;ized'rzwith'z'respeet: to th'? 'reticle image H0} at which; ztiin'enp-the proper tracking condition for efiectivefirez' haying-independentdisplacement about two in" a-.=member:-1I lzh formed a's: ar sectori of a r-cireleiFhavingi-its centeralongatherpivotfiaxis:I I 2 of' tlre m2111- obtained; "htanualicontr'ol z'mem benc'l 8-- im-Figz; 4'; isishowni as being'l of the? type e elevation;

ence of this circular member I I I is a cable II 3 which is maintained in close contact with this circumference by means of an idler pulley H4. Upon motion of manual control I8 about axis I I2, cable I I3, operating against the pull of a spring I I6, whose remote end is fixed as at I II, will serve to translate arm 50, and thereby displaces the ball carriage 5| of the variable speed drive 52 in the same manner as in Fig. 3. The rotation of the output cylinder 56 of the variable speed drive 52 is then led through differential 58 to output shaft 64 controlling a torque amplifier 66 driving the elevation pinion I6 engaging the elevation rack or ring gear I1 and thereby driving the entire apparatus here shown, together with the guns fixed with respect thereto, in elevation, at a rate proportional to the elevation displacement of manual controller I8. This action is exactly similar to that of Fig. 3.

At the same time, this motion of arm 50 moves.

a lever 68 about a pivot 69 and thereby displaces the elevation mirror IIII, as by means of a suit. able cable H8, or other mechanical coupling, to:

displace the line of sight determined by the reticle image III] in the same direction as the' In addition, the moguns are starting to move. tion of arm 56 moves a lever I6 about a pivot TI and thereby displaces the ball carriage 86 of vari-; able speed drive 81, whose drive disc 95 is driven.

from motor H9 in the manner to be described.

The output cylinder 83 of variable speed drive 3'! drives a gear I2 I- meshing with an elongated pinion I22 which is rotatably mounted on a link I26v coupled to 'lever I6, and which is internally threaded to receive a threaded shaft I23 movable in translation together with the ball carriage 96.

as cylinder 88 turns, pinion I22 is rotated and the screw shaft I23 is thereby screwed in or out. in a sense to restore ball carriage 86 toward its neutral position. In this respect, the device of Fig. 4 is similar to the linkage system 83, 82, I9, 92, 94, 8I of Fig. 3, and serves to delayably rotate I gear I2I by an amount proportional to the dis-.

placement of manual controller I8, and also proportional to the angular velocity of the guns, and

hence of the target when tracking therewith.

Gear I2I also operates through suitable gearing I24 to rotate a screw 93 carrying the nut 95' which supports the pivot 69, andthereby delayably rotates mirror IOI by the amount necessary to withdraw the line of sight from its original advanced position and to displace it from the gun orientation by the proper prediction lead angle: Pivot I1 is made adjustable under the control of J the range knob 98 and time-of-flight cam 96 in the same manner as in Fig. 3. Gear I2I also adds its motion to that of cylinder 56 in difierential 58, also as in Fig. 3.

As thus far described, the present system is identical with that of Fig. 3, merely replacing the sight I3 by an equivalent sighting device IOI, I03. In order to introduce the super-elevation component of the elevation lead angle, output shaft 59 of differential 58 operates through a worm I26 and a worm wheel I21 to rotate a cam I28, whose follower I 29 is thereby translated in proportion to the cosine of the angular displacement of shaft 59, and therefore in accordance with the cosine of the angle of elevation of the gun. The displacement of follower I29 correspondingly displaces arm I 3I carrying the rack I32 cooperating with a pinion I33, which is thereby rotated through an angle corresponding to the cosine of the angle of gun elevation. Pinion I33 actuates a flexible shaft I34, which in turn rotates a screw shaft I 36 rotatably mounted upon arm 50. Screw I36 in this manner translates a nut I3'I mounted thereon, which carries the pivot I38 for lever I6. Thus, the displaces ment of lever I6 produced by manual control I8 is modified by an additive component proportional to the cosine of the angle of elevation. This modification of the displacement of lever I6 produces a corresponding modification of the resultant angular displacement of output cylinder 88 of variable speed drive 31, which thus operates through screw 93 and nut 95 to modify the lead angle of mirror IIII, which is thus controlled both in accordance with the prediction lead angle and the superelevation lead angle to provide the proper resultant lead angle in elevation for effective fire.

Shaft 59 is coupled to torque amplifier 66 driving pinion I 6 with respect to fixed elevation rack II, similar to the arrangement of Fig. 3.

The control of the azimuth mirror I03 is exactly similar to that of the elevation mirror IOI and need not be further described, similar elements being given similar reference characters, but primed. It is to be noted, however, that the angular motion of the line of sight produced by azimuth mirror I03 occurs in the slant plane determined by the gun orientation and the pivot axis I02 of mirror IIlI parallel to the gun elevation trunnions. The azimuth control of the guns, however, is generally about a fixed vertical axis, as in Fig. l, or in a horizontal plane. In order to properly control the guns, therefore, it is necessary to convert angular displacements in azimuth in the slant plane into the corresponding azimuth angular displacements in the horizontal plane. As is well known, this conversion may be performed by multiplying the slant plane azimuth values by the secant of the angle of elevation, or by dividing by the cosine of the elevation angle. For this purpose, output shaft 59 of differential 58', corresponding to output shaft 59 of Figs. 2 and 3, which is angularly displaced in accordance with the gun slant plane azimuth, serves to actuate the drum cylinder I4I of a variable speed drive I42, whose ball carriage I43 is translated in proportion to the cosine of the angle of gun elevation by means of arm I3I. By so doing, the disc I44 of variable speed drive I42 is actuated in accordance with the ratio of the displacement of cylinder I4I to that of ball carriage I43, and will therefore be displaced in proportion to the product of the displacement of shaft 59' by the secant of the angle of elevation.- The output derived from disc I44 is then led to a torque amplifier 66, similar to that of Figs. 2 and 3, and serves to actuate the azimuth drive pinion I 3 cooperating with the azimuth ring gear I? to rotate the entire apparatus in azimuth.

As thus far described, the present device of Fig. 4 has added the superelevation control and the correction for slant plane data to the device of Fig. 3. In order to adjust the settling time in accordance with the time of flight, range knob 98 and cam 96 actuate a link I46, which in turn is pivoted to a lever I47 having a fixed fulcrum at I43. In this manner, lever I41 adjusts the ball carriage I48 of a further variable speed drive I49, whose drive disc I5I is driven at con stant speed from constant speed motor I I9, in accordance with tiine-of-flight. The output cylinder I52 of variable speed drive I49 then drivesv the drive discs 39 and. 96' of variable speed drives; SIand 81'. In this manner, the settling time of the variable speed drives 9? and 81 is adjusted 13 in accordance with the time of flight or range of the target, so that optimum performance may be obtained both for close-in targets and for distant targets.

The apparatus of Fig. 2 may be adjusted similarly to allow for close-in or remote targets by adjusting the value of resistor 41 or condenser 46. Preferably, for reasons of simplicity, resistor 41 is made adjustable for this purpose.

Although the above modifications have been described as using the friction disc type of variable speed drive, it is to be noted that any other type of device yielding an output rate of turn corresponding to an input displacement may be used.

.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. A computing gun sight comprising a sighting device mounted on and adapted to be moved with a gun, means for producing a control voltage corresponding to a desired angular velocity of said gun, means responsive to said voltage, and including a speed generator adapted to produce a speed voltage proportional to the angular velocity of said gun, for driving said gun and sighting device at said desired angular velocity, and means for offsetting the orientation of said sighting device from that of said gun in a direction opposite to the motion of said gun and in proportion to said angular velocity, comprising means for displacing said sighting device displacing said sighting device relative to said gun in the same sense as the motion of said gun and in proportion to the rate of chang of said control voltage whereby an aided tracking control of said sighting device is provided so that 'it may be more readily tracked with a target.

3. A computing gun sight as in claim 1, further including means responsive to a change in said control voltage for initially displacing said sighting device relative to said gun in the same sense as the motion of said gun and for delayably removing said initial displacement, whereby said sighting device may be stably and easily tracked with a target.


References Cited in the file of this patent UNITED STATES PATENTS Great Britain Mar. 28, 1938

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2894330 *Jul 23, 1952Jul 14, 1959Kollsman Instr CorpAstrocompass
US2977858 *Jul 16, 1958Apr 4, 1961Hotchkiss BrandtAiming device for mortars
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US3659494 *Jul 31, 1969May 2, 1972Itek CorpFire control system for use in conjunction with electronic image motion stabilization systems
US3727514 *Apr 17, 1969Apr 17, 1973Land Weapons Mfg WorkshopMeans for controlling the firing of a gun against a movable target
US4313272 *Apr 25, 1979Feb 2, 1982Laser Products CorporationLaser beam firearm aim assisting methods and apparatus
US4313273 *Apr 25, 1979Feb 2, 1982Laser Products CorporationFirearms and laser beam aim assisting methods and apparatus
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US8646374 *Jul 25, 2011Feb 11, 2014Raytheon CompanyWeapon station and associated method
US20120024143 *Jul 25, 2011Feb 2, 2012Raytheon CompanyWeapon Station and Associated Method
U.S. Classification89/205, 89/41.15, 89/41.19, 89/41.1, 235/404
International ClassificationF41G3/06, G06G7/80, F41G3/00, G06G7/00
Cooperative ClassificationG06G7/80, F41G3/06
European ClassificationF41G3/06, G06G7/80