T9, W4@ A. G. @@@LEY @AMAN REMOTE CONTROL SYSTEM AND APPARATUS Filed Oct. 28, 1943 4 Sheets-Sheet l I3 c L IMC Ü ‘WNW/@M1005 __,_ 'wm-0H „fil I9 g I4 42 IN VEN TOR. A . G.COOLE Y Nov.; 19, 15946„ A. G. QOOLEY > 291431.34? REMOTE CONTROL SYSTEM AND APPARATUS Filed OGL 28, 1943 HJVIENTOR. AAB .COO mw Nov. 19, l946. A, @_ @@@LEY ÈABLÍQ'? REMOTE CONTROL SYSTEM AND APPARATUS Filed Oct. 28, 1943 ' ma@ 4 `Sheets-Sheet 3 Nov. 19, 1946. _A G, @Cm www REMOTE CONTROL- SYSTEM AND APPARATUS Filed Oct. 28, 1943 4 Sheets-Sheet 4 ÍNI/ENTOR. A.G.COOL_EY Mlm 'GM/wb) Patented Nov. 19, 1946 2,411,147 UNITED STATES- PATENT OFFICE 2,411,147 ' REMOTE-CONTROL SYSTEM AND APPARATUS . Austin G. Cooley, New York, N. Y., assignor to Times Telephoto Equipment Inc., New York, N. Y., a corporation of New York Application October 28, 1943, Serial No. 508,041 l 6 Claims. This invention relates to the remote control of the position oi' objects, such as guns, searchlights, pointers and the like, through the instrumental ity of electric motors. One object of the invention is to provide a re mote control system in which the position of the movable object may be controlled with great pre cision and in which considerable power is avail able, if required. Other objects and advantages ofthe invention will become apparent from the following descrip tion of the preferred embodiments thereof shown in the accompanying drawings, wherein Fig. 1 is a diagrammatic view of a remote con trol system utilizing two synchronous motors at the receiving station, one operating at constant speed and the other at variable speed. Fig. 2 is a similar view of a system utilizing a Another object of the invention is to provide a 10 single control circuit for a plurality of transmis sion channels. which the number of conductors or circuits be Fig. 3 is a view of a modified form of phase tween the control station and the receiving sta shifting means that may be used at the control tion is reduced to a minimum, and in which the station. ‘ construction of the apparatus employed is simpler system of the above-mentioned character in than that heretofore proposed. , Fig. 4 illustrates another modification employ ing optical elements. A further object of the invention is to provide Fig.,5 is a plan view of the disc shown in Fig. 4. an electrical remote control system in which the Fig. 6 illustrates a form of motor mechanism control current transmitted from the control sta tion to the receiving station is of such character 20 in which no differential gearing is required. Fig. ’7 is a diagrammatic View of another modi ' that it may be amplified at the receiving station iication of the system according to the invention. to supply the operating power required at that Referring to the drawings, Fig. 1 illustrates a point without introducing an error in the re remote control system 'comprising two single sponse of the motor mechanism. ' vA still further object of the invention is to pro- 25 phase synchronous motors II and I2 connected to an alternating-current supply circuit I3. The vide improved control apparatus responsive to the motors II and I2 are arranged to drive amem diiïerence in phase or frequency between two a1 ber I4 (constituting or connected to an object to ternating currents. Y be controlled) through differential gearing I5, In accordance with the invention, accurate con trol oi’ an object to be positioned is effected by 30 whereby the member I4 is moved in accordance With the difference in speeds of the motors I I and controlling the' speed of a continuously rotating I2. single-phase synchronous motor. In its preferred In order to vary the relative speeds of the mo form, two synchronous motors or two synchronous elements of a combined motor are differentially tors II and I2 to eifect desired control of the ` connected to actuate the controlled (operating) 35 member I4, means is provided to alter the phase or frequency of the current supplied to the motor member or shaft in accordance with the diiïer I2. As shown, phase-shifting means I6 of the ence in speeds between the two motors or motor type capable of shifting phase more than 360° is elements. The speed of one or both of the motor connected between the supply circuit I3 and mo elements is controlledjliy,v varying the phase or tor The phase-shifting means I6 comprises frequency ' of the curr‘eiftf'oir- currents transmitted 4o two I2. stationary field poles Il and I8 disposed 90° from the primary station or control station to the apart and provided with windings connected to receiving station. The frequency of the control the circuit I3 directly and through a condenser current is Ípreferably oi' the order of 1000 or 2000 I8, respectively. The capacity of the condenser cycles per second, the motor element being con structed to run on current of this frequency and 45 I9 is such that the magnetization of one field pole is displaced 90° with respect to the other pole. to follow variations in frequency to effect the de The armature consists of two opposite salient sired control. The control current may be am poles 20 having windings connected in series so pliñed at the receiving station without ailecting that the sum of the -induced currents is substan the accuracy of control and may be transmitted over long high-resistance or inductive circuits 50 tially constant in any position of the armature without difilculty, since'the essential'character istic of the control current, i. e., the frequency, will not be changed by alterations in the electri cal characteristics of the connecting circuit or the amplifier. and is retarded or advanced in phase as the ar mature is rotated by the hand-wheel 2|. With Ithe described arrangement, it will be evident that l’motor II rotates at a constant speed and the 'speed of motor I2 is dependent upon the adjust 55 ment of the phase-shifting means I6, the rota `animer F) m , plifiers. Considerable power is available, if re tion of the armature of motor i2 being advanced quired, and this power need not be transmitted or retarded two poles with respect to the arma over the control circuit. No attempt has been ture of motor ii for each complete revolution of’ made to illustrate the exact proportions and the armature of the phase-shifting means. structural details of the phase-shifting means it. The frequency of the alternating current sup» 2b, as such devices are well irnown in the art plied to the motors ii and i2 is preferably of the and are described in prior publications, includ order of 1000 'or' 2000 cycles and the motors may ing my prior Patent No. 2,138,398, dated No= be of the reluctance or phonic wheel type similar vember 29, i938. to that described in my prior Patent No. 2,257,158, A modifledforrn of phase-shifting means which dated September 30, 1941. If desired, other syn l( may be used at the control station invplace of chronous motors of known design adapted to op means 2b is illustrated in Fig. 3. This construc erate on the particular frequency chosen may 'be tion may be small and compact so that less torque utilized in carrying out the invention. However is vrequired and a greater phase shift obtained frequencies in the so-called “audible-frequency” with a given angular displacement of the control range are advantageous for many applications oi member. As shown, it comprises a movable con the invention. In particular, control currents of trol member ¿45 in the form of a plate or vane this frequency may be transmitted at low power which is integral with or secured to a compass or level and ampliiied at the receiving station in a other instrument or control element. The mov» vacuum-tube amplifier to increase the power available without affecting the accuracy of con 20 able vane db is provided with spaced iron inserts de supported for movement along a row of trans trol. Furthermore, separate frequencies for driv lating devices in the form of stationary electro ing the motors may be transmitted over a single magnets d8, 69, 50 and si. The spacing between control circuit and separated yat the receiving sta the inserts ¿i6 is such that as the right-hand edge tion by conventional nlters. A system of this character is illustrated in Fig. 25 of one insert is moved to the middle of the core of the magnet 65B, the left-hand edge of the next 2 wherein an oscillator 26, for example of a fre quency of 1800 cycles, is utilized to generate the control frequency. The oscillator 24 having a constant frequency output is connected through phase-shifting means 25, which may be similar to the phase-shifting means it of Fig. 1, to one primary winding 26 of a transformer 27. The os insert lies above the middle of the core of the elec tromagnet 5 i, and the width of the inserts is sub stantially equal to the distance between the cen» tral axes of adjacent magnet cores so that the magnetic iiux induced in said inserts remains constant as the vane ¿l5 is moved (assuming that the electromagnets are of equal strength). cillator 2d is also connected through a frequency The electromagnets dit, d2, 50 and Eil are con changer 28 to a second primary winding 29 of nected to an alternating-current supply circuit transformer 2l, so that a constant frequency of, 85 53, for example of a frequency of the order of say 1200 cycles, is applied to the winding 29. Cur 1000 or 2000 cycles. However a condenser td'is rents of a frequency of 1800i cycles and of a con connected in series with electromagnet 130 to dis stant frequency of 1200 cycles are induced in the place vthe phase of the current traversing its coil secondary winding 30 of transformer 2l, said sec 90°. Similarly, means such as a .transformer 55 ondary winding being connected to the control land condenser 5d is provided to displace the phase circuit Si. At the receiving station,y a single of the currents traversing the electromagnets t@ phase synchronous motor 365 is connected to the and 5i by 180° and 270°, respectively, with refer control circuit 3i through the 1800-cycle filter 35 ence to that traversing' the electromagnet de. In and an amplifier 36, whereby the motor 3d is this manner .the algebraic sum of ythe vfiuires in driven by the 1800-cycle component of the trans the insert ¿it opposite the electromagnets is shifted mitted current, amplified as may be required to in phase 360° as the insert is moved from a' posi give the necessary power output. A second syn tion approaching magnet dit to a position beyond chronousrmotor 3i, similar to the motor 363 but magnet 5i (or vice versa). A stationary mag driven at constant speed by the 1200-cycle com ponent of the current in the control circuit, is 50 netizable core 5e opposite the electromagnets tit-_5i carries a pick-up coil d@ in which current connected to the control circuit through the 1200-= is induced of the same frequency as that of the' ‘_f cycle nlter 38 and an ampliiier 39. The member supply circuit 53 but retarded or advanced Vin ¿l0 to be controlled from the primary station or phase by 360° as each insert d@ moves past the control station is connected through diñerential gearing ¿li to be moved in accordance with varia 55 'core 50. The terminals of the pick-up coil d@ are connected to the control channel, for ex tions?in the speed of the motor 3d as the adjust ample 'as illustrated in connection with the phase ment of the phase-shifting means 25 at the con shifting means 25 in Fig. 2. in ythis manner the trol station is changed. If the motors 311i and si speed of a synchronous motor at the remote sta have equal numbers of poles, the motor te will. tion is varied in accordance with the movement run on. l800-cycle current at one and one-half or adjustment of a controlling member attached times the speed of the motor et on 1200-cycle to the vane ¿55. current. Accordingly gearing ¿32 may be provided Another modified construction of phase-shift-vv Y ., to establish the desired speed relation between ing means utilizing a series of translating devices the drive gears of the differential gearing ¿ii or, of different character that may be employed at alternatively, the motors may be designed to run> the primary or control station is 'shown in Figs. at the same speed on diiïerent frequencies. e and 5. in this arrangement, a pivoted-disc iii It will be apparent that the object to be con having a series of equally spaced holes t2 around trolled may be positioned or moved, in the sys its periphery is employed in an optical system to tems shown in Figs. 1 and 2, precisely in accord shift the phase of an alternating current to any ance with the adjustment of the phase-shifting desired extent (from a fraction of a cycle tosev means, _and the accuracy of control is not af eral cycles or more). The disc _Si is arranged to fected by variations in the supply voltage or other variations which are likely to occur, such as the be turned bythe control element. In the particu-` lar embodiment illustrated, a fluctuating limiti-_Q., resistance, inductance or leakage resistance of the control circuit, or changes in the gain of the am 75 source 65 is arranged to illuminate a series of " Y 2,411,147 5 6 photocells 88, 81, 88 and 88 through _successive holes in the disc 8| as the latter is rotated. The and |0I, and a commutator |02 as shown. The field poles 84 and 88 lare carried by a rotatable light source 88 may be a neon glow-discharge or yoke or frame |05 on a shaft |08 projecting from arc-discharge lamp connected to an alternating current supply circuit of constant. frequency whereby a pulsating iight of constant frequency the motor casing 83, said shaft being provided with a worm thread“ |01 at the upper end thereof meshing with a worm gear |08, and slip rings |08 through which current is supplied to the ~field is obtained. A suitable opticalsystem including planoconvex- lenses 1| and 12,'and an aperture` Ywindings H0, Ill on the fleld poles 84 and 95. plate 18, is constructed and arranged to cause the The motor` terminals, connecting leads and other beam of light passing through the holes in the 10 conventional elements of the motor are not illus trated in detail for the sake of simplicity. The disc 8| to sweep over the photocells one after the other as the disc rotates. numbers of teeth in the rotors 80 and 8| have a ' The lenses 1|, 12, and the aperture in the plate predetermined ratio, say 2:'3 incase frequencies of 1200 and 1800 cycles are supplied to the respec 18 are correlated with the size and spacing of the holes 82 and the location and extent of the cath 15 tive motor elements, so that normally there is no tendency for the field poles 84, 85 to rotate and odes of the photocells to insure that the total the shaft |08 remains stationary. When the rel output current from the cell or cells illuminated ative phase or frequency of the currents supplied at any instant remains substantially constant. to the motors is changed by the phase-shifting The spacing of the holes 82 is such that as one hole moves past the edge of the aperture in the 20 means at the control station, the shaft |08 is ro plate 18, the adjacent hole permits light from tated to a corresponding extent. As shown, the worm gear |08 may be attached to a pointer ||8 the source 88 to strike one of the end cells. Thus to indicate the change in adjustment of the con the photocells are successively and repea-tedly illuminated with pulsating light from the lamp trol means at the control station. A bell-crank 85, always in the sequence 88-88-81--88 when 25 lever I | 8 and rod ||1 may also be provided to ac tuate an object to be controlled. ` As stated, the the holes in the disc 8| traverse .the light field mechanism described is merely illustrative of the in the direction indicated by the arrow, and in principles of the invention and the structural de the sequence 88-81-88-89 for rotation of the tails may be widely varied without departing from disc in the opposite direction. ' In accordance with the invention, the output 30 the invention. Another modification of the remote control sys currents of lthe respective cells are phase-con tem embodying the invention is shown in Fig. '1. trolled in a predetermined manner and combined Referring to this ñgure, an electric motor |2| is in the primary winding of a transformer 18 so shown at the primary or control station, said mothat a control voltage is generated in the second tor being arranged to drive two alternating-cur ary winding of said transformer which is uni rent generators |22 and |28 to generate control formly and continuously shifted in phase as the currents of constant frequencies, say 1200 and disc 8| is rotated. As shown. a .conventional 1800 cycles per second. The generators | 22 and two-stage amplifier comprising tubes 11 and 18 is provided for the photocell 88. A similar ampli |23 are connected to the control circuit |24 fier 19, 80 is provided for the photocell 81, except 40 through two phase-shifting devices |25 and |28. These devices may be similar to that shown in that a condenser 8i is connected in the input Fig. 1, 3 or 4, and are arranged for control in the circuit of the tube 19 to displace the output cur opposite sense 'by a hand-wheel |21, i. e., the rent 90° with respect to that of the amplifier 11, phase of the output currents from the generators 18. Likewise ‘the amplifier 82, 83 for the photo is shifted in opposite directions when the hand cell 88 includes a coupling transformer 84 so that wheel |21 is turned, thus providing a more rapid the output current is displaced 180° with respect change in the frequency ratio of the control cur to that of the amplifier 11, 18; and the amplifierA rents. A position indicator |28 is also shown at 85, 88 for the photocèll 89 is similar to 'the am the control station to indicate to the operator or pliiler 82, 88 except for the condenser 81 arranged to effect a further phase displacement of 90°. or a 50 attendant the position of the controlled device at the remote station. This position indicator may total of 270° with respect to the output current be constructed like the synchronous-motor mech from the first cell 88. The phase-control ar anism of Figs. 1 and 2, or that shown in Fig. 6, rangement illustrated is preferred but a modified and may also be used at the control station in the arrangement may be employed in carrying out 55 systems of Figs. 1 and 2, if desired. AA ñlter-am the invention if desired. plifler |29 for the 1200-cycle current and a second Instead of using two separate synchronous mofilter-amplifier |80 for the 1800-cycle current are tors and differential gearing', as shown in Figs. 1 connected between the control circuit and the »and 2. a unitary motor mechanismV having two motor mechanism |3|. The latter may be simi synchronous motor elements as 4shown in Fig. 6 may be used. Referring to this figure, a preferred 60 lar to that shown in Figs. 1 and 2 or Fig. 6, and is shown as arranged to control the elevation of a form of motor mechanism comprises upper and gun |82 by means of a worm |33 and worm gear _lower toothed rotors 80 and 9| secured to a shaft |84. Obviously the system may be utilized to con 92 which is supported for rotation in the motor trol the position of other objects, as already ex casing 88. Each of said rotors is disposed between a pair of salient field poles 94, 95 and 96, 81, re 65 plained. spectively, thus forming two separate synchronous It is to be understood that the invention is not motors with their rotors mounted on the same limited to the details of the mechanisms illus trated by way of example, and that these may shaft. Each rotor may be connected to the shaft 82 through a resilient connection, as described in be modified without departing from- the scope of my Patent No. 2,276,936, dated March 17, 1942. 70 the invention as defined in the appended claims. The shaft 82 also carries an armature 88 of a I claim: universal motor element which _is employed to 1. In a remote control system, in combination,` bring the synchronous motors up to speed in an object to be controlled, motor mechanism ar ranged to position said object, said motor mech starting. The start motor includes a stationary core member provided withfleld -windings |80 75 anism comprising. two single-phase synchronous l 2,411,147 motors and a pivoted actuating member tuned in accordance with the difference in rotative speeds of said motors, a single control-circuit to said motors, _means for supplying relatively variable frequency alternating currents to said control cir 5 varying the dißerence between said frequencies, means for impressing both currents on said con trol circuit, fllter means at the receiving station for separating said currents oi' different ire quencies, synchronous motor means at the receiv ing station connected to be responsive to the cuit- and for separating the currents at the end of said circuit adjacent the motors to vary the relative speeds 'of said motors and thereby controlk transmitted currents of both frequencies and a the position of said object. in accordance with variations in the frequencies - - / 2. In a remote control system, in combination, 10 a control circuit, a constant-frequency source of alternating current, phase-adjusting means of the type capable of shifting phase more than 360° interposed between said source and said control circuit, a frequency changernalso interposed be tween said source and said control circuit and a controlled member `actuated by said motor means of said currents.> . . 5. In a remote control system, in combination, a. control station, a receiving station, an oscil lator at the control station, a frequency changer connected to said oscillator, means for combining the output currents of said oscillator and said frequency changer, phase shifting means for control actuating device including a continuously swinging the frequency of one current relative to rotating synchronous motor connected .to said the other, means for transmitting the relatively ' control circuit whereby its rotative speed at any variable-frequency currents to the receiving sta `particular moment is aifectedby operation of said 20 tion, a movable member to be controlled at the phase-adjusting means, said actuating device fur receiving station anddiiferential motor means ther comprising a second motor and tuning means for actuating said movable member connected to for rendering said second motor responsive to the be responsive to the frequencies of the transmitted output current of said frequency changer. currents. 3. In a remote control system, in combination, 6._ In a remote control system, in combination, a control station, a receiving station, a control circuit connecting said stations, a source of audio an object to be controlled, a control circuit, means for generating alternating current oi' constant frequency, a frequency changer connected to said generating means, and arranged to provide output frequency current at the control station, means including said source for'impressing currents of two different frequencies on said control circuit, current of a different constant frequency, means ñlters at the receiving station for separating said for impressing the output currents of said gen currents of different frequencies, motor means at erating means and lsaid frequency changer upon the receiving station connected to said control said control circuit and fo;` varying the phase or circuit and responsive to both said currents, a frequency relation between the resultant currents movable control element at the control station and 35 of different frequencies traversing said control means including said control element for shifting circuit, filters for separating the last-mentioned the phase or frequency of one of said currents in currents 'at the remote end of the circuit, rotating the control circuit to effectsJ corresponding re synchronous motor means connected thereto to sponse oi' the motor means at the receiving sta operate at relative speeds dependent upon the tion. ` 40 changes in the phase or frequency relation be 4. In a remote control system, in combination, tween the currents traversing the control circuit a control station, a receiving station, a control and a connection between said motor means and circuit between said stations consisting of a single the controlled object to move said object in ac~ circuit, an audio-frequency oscillator at the con cordance with the changes in said phase or fre trol station, means for deriving currents of two 45 quency relation.’ ‘ different frequencies from said oscillator and for \ ‘AUSTIN G. COOLEY.