US 2178089 A
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J. B. WALKER SYSTEM OF REMOTE CONTROL Filed Feb. 8, 1937 Oct. 31, 1939.
Patented Oct. 3l, 1939 UNED STATES SYSTEM 0F REMOTE CON TBOL `oseph B. Walker, Hollywood, Calif., assignor of one-third to Frank Capra and one-third to Sheldon K. `iohnsoin, both of Los Angeles Connty, cani.
Application February 8, 1937, Serial No. 129,756
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This invention relates to a remote control system, and it has for its primary object to provide a method of and means for controlling a distant object by radio While preventing unauthorized persons from controlling the operation of or interfering with the operation of such distant object.
Broadly stated, the invention resides in setting up at a central or control station, electric impulses of a given order or value, scrambling or garbling said impulses to destroy their order or relation, delivering the garbled impulses to a radio broadcasting apparatus by which they are delivered as radio Waves to a radio receiving apparatus at or adjacent the distant object to be controlled and where by a reversal of the scrambling operation they are restored to their original order or form and utilized in the common way to control such distant object. The invention goes further than this broad idea, and as will presently be seen contemplates continuously and successively changing the identity of the transmitted signals. For example, the order of electrical impulses set up to effect a given movement of the distant object, upon one energization of the machine will diier from the order of the electrical impulses necessary to effect the same movement of the distant object upon the next energization of the machine. Expressing it in another way: If we set the mechanism of the distant object, such as an airplane for example, so that it will turn right under the impulse of electrical impulses set in operation under the actuation of an M key at the sending station, the 4 electrical impulses of radio frequency which pass from the sending or control station to the distant object or automat will be different for each. successive operation of the M key at the sending station.
The invention is not limited to any particular type of apparatus for garbling and then reassembling electrical impulses, as described, because it has heretofore been proposed in the art of secret communication to employ machines which will receive a straight message at a sending station, automatically gai-ble the same to unintelligible form and when said message is delivered to and imposed upon alike machine at a receiving station, such message is decoded or restored to its original form.
An apparatus of this general character is shown in my co-pending application, Serial No. 120,457, led on the 13th day of January, 1937, and I propose to use an apparatus of that sort at the impulse creating, garbling and reassembling (Cl. 25th-2) mechanism of the present invention. It will be l seen as this description progresses that mechanism of this nature differs from many conventional coding and decoding machines in that it continually and successively changes the character of the electrical impulses sent out upon each successive actuation of any given key. Insofar as they are applicable, I have used the same reference characters in this application as are used in my companion application aforesaid, and Fig. 18 of said companion application is identical with Fig. 1 of the accompanying drawing constituting a part of this application, wherein:
Fig. 1 is a general diagrammatic view, and
Fig. 2 is a detail showing how a plurality of impulses may be required to actuate a single remotely controlled element.
For the purposes of the present application, it suiiices to say that A and B indicate mechanism corresponding to the units A and B of my aforesaid application and functioning when keys 5 are depressed to deliver electrical impulses to conductor 8l in a constantly changing order, these electrical impulses being in turn delivered to solenoid magnets 25 of a selector unit C. These magnets actuate bars 2S to control selector bars 28, these bars V28, in turn, closing electric contacts 3@ leading to the plug-in jack or block 3io, the output cable of which is indicated at Bla. In actual practice there are thirty-two of the bars im, enough to take care of all of the letters of the alphabet and some numerals. For purposes of explanation, I have shown only three of these bars and their corresponding contacts 3B, with their leads to the plug-in jack 3io, all of these parts being identical with corresponding elements of my co-pending application aforesaid.
The output leads from the plug-in jack 3io lead to a radio transmitting set 36. The scrambled impulses delivered to conductors 35 from the units A and B are delivered from the transmitting set 36 and from the antenna 31 thereof, as radio waves. It will be understood that the conductors which lead from the contacts 3B to the plug-in jack 3io are suiicient in number to take care of all of the letters of the alphabet. I have shown three merely for pur` poses oi illustration.
@la designates merely the sheath of an electrical cable, in which the conductors 35 are contained, these conductors corresponding in number to the conductors which lead from 30 to the plug-in jack 3io. Let us assume now that the A key of the bank of keys 5 is depressed, and that by reason of the garbling eect produced by A and B, these impulses reach the antenna in the form (dots and dashes, for example) that they would have had if an M key had been depressed instead of A and no garbling had taken place.
These dot and dash radio signals corresponding to M will be transmitted through the ether, be received by antenna 38 of a radio receiving set, 39, which, with the parts now to be described, may be carried by a remotely controlled, dirigible object, such, for example, as an airplane, part of thebody of which is indicated at 40. This radio receiving set converts the waves of radio :Uequency from the antenna 38 to waves of the proper frequency for the actuation of solenoid magnets 4I, the said electrical impulses being delivered to said magnets through conductors 42.
The radio transmitting set 3$\ and the radio receiving set 39 are designed, through conventional tuning apparatus, in such fashion that only a given one of the magnets 4l will respond to an impulse from a corresponding one of the conductors 35. Consequently, there will be as many of the magnets 4| as there are keys 5, and there will be as many of the keys 5a.- in the unit A1 as there are keys 5 in the unit A.
The keys- 5a of the unit A1 do the same thing with respect to the decoding apparatus on the airplane or "automat and with respect to the mechanism B1, C1 that the keys 5 do with respect to the apparatus A and B. That is to say, if we press a key 5, which we will assume to be represented by three dashes, the units A, B and C at the sending station, under the influence of the perforated tape or nlm, convert these impulses into what we may assume to be a dash and a dot.
'Ihese impulses, through one of the magnets 4|, depress a key 5a, which corresponds to a dash and a dot, and B1 and C1, upon the automat, through the use of a correspondingly punched tape, as disclosed in my aforesaid application,Y Serial No. 120,457, change the value of this dash and dot back to the value of the three dashes. In other words, these impulses are restored to their original order and value and delivered, through conductors 44, to any suitable remote control mechanism.
For purposes of explanation, I have shown these conductors leading to solenoid magnets 45, 46 and 41. The core 48 of magnet 45 may be directly connected to the throttle lever 50 of the airplane 40. Magnet 46 may be utilized to have a bridge piece 46a, carried by its core, bridge the contacts 48a to energize a motor 49.l This motor may be utilized to perform any desired function, such for example, as shifting the ailerons or the rudders of the airplane. Magnet 41 may, in like manner, bridge contacts 5I to energize the magnet 52 and withdraw latch 53 of a/bo-mb release lever 54, said bomb being indicated at 55.
It. will, of course, be understood that the invention is not limited to the particular type of apparatus being controlled. While a system of this sort is of considerable value in military operations, it is equally as true that it may be used to great advantage in the arts of peace.
For example, the pipe lines through which oil and gas are conducted for thousands of miles are provided with valves, some of which are located in remote places and many miles from the nearest plant. It is clear that the motor 49 could be utilized to actuate such valves. Also electric switches in extended power transmission lines are frequently located many miles from the nearest station or substation, and these switches may also be remotely controlled by this system.
In like manner, large gate valves are disposed in Water mains controlling, in some cases, the entire water supply of a city which could be cut off by the unauthorized or malicious closing of a remotely located valve. The use of this system would guard against any such possibility.
It should be understood that I make no claim to the broad idea of remotely controlling valves, switches, airplanes, torpedoes or other object, my invention residing in the provision of accurate and reliable means for preventing a remotely controlled object, employing this system, from being operated by unauthorized persons and for preventing such unauthorized persons from interfering with the proper operation of such remotely controlled elements under the influence of the original control station. Thus, if magnet 41 oi the bomb release were connected by its conductor 44 with that terminal of C1 corresponding to the letter M, the pressing of that key 5 at the sending station corresponding to letter M would set up a group of impulses peculiar to letter M, -garble the impulses constitutng said letter, transmit the garbled impulses by wireless to the remotely controlled apparatus 40, retranspose the garbled impulses and cause them to actuate that magnet, viz., 41, which is wired to that terminal of C1 corresponding to the letter M. v
I am aware of the fact that it is old kto electrically control airplanes and the like through remote control devices. 'Ihe important diierence between my structure and the devices of the 3 designedly or accidentally imposed thereon) by making each of the remotely controlled parts such as the throttle 50, motor 49, or bomb release 54 responsive only to a plurality of the electrical impulses.
In said Fig. 2, I have shown an arrangement wherein it requires the impulses from five separate ones of the keys 5 to actuate a motor 49x corresponding to motor 49. In this ligure, any ilve of the conductors 44m, oi' which there are thirty-two, corresponding to the conductors 44 of Fig. 1, may be connected to magnets 48x arranged to close contacts 46g, arranged in series in the control circuit 49C of the motor. Everything shown on the drawing except Fig. 2 constitutes a part of Fig. 1, because the mechanism on the remotely controlled apparatus is in direct co-Kactive relation with A, B and C, even though some of the electrical waves employed are of radio frequency and bridge the gap between antennas 31 and 38.
While I have illustrated ilve magnets in Fig. 2 to complementally control the motor, it will be understood that this unit could be controlled by a group of three or a group of six or any other number. Thus, if these were connected to the output leads 44x, corresponding to the keys M. A, R, c, H, it will require the sending or' this complete code word from the sending station to bring about an actuation of motor 49x. It should be understood thatleads Mx of Fig. 2 correspond to leads lli in Fig. 1.
It will be clear that the possible combinations under this arrangement would be almost limitless, because some of the magnets of the same group illustrated could be utilized in other combinations, as for example, in the substitution of the Word month for the Word March for the code word. Here the rst and last letters would be the same, only the intermediate letters being changed.
In utilizing an arrangement such as is illustrated in Fig. 2, and assuming the Word March to be the code Word for energizing motor Mx, the operator at the sending station would actuate the keys M, A, R, C, H, of the bank of keys 5. The mechanism described would discharge the garbled elements of this code word from antenna 3l. These garbled impulses would be picked up by antenna 38, transposed at B1 and C1 to their original form, delivered through Aida: to magnets lita', and when all of these have been energized to close the circuit lec, motor figa: will respond.
Thus, the control operator would, in eiect, talk to the automat or airplane D by writing on the sending keyboard at keys 5 the code Word for the operation to be performed. The receiving set 35, 39, A1, B1, C1` would translate this automatically into impulses corresponding to the pre-wired hookup on said automat.
Having described my invention, what I claim is:
1. In combination, a remotely controlled dirigible body, electrically actuated controlling means for said body, the energization of which effects the bodily movement of said body, means for controlling a supply ofenergy to the electrically actuated controlling means, comprising an electric circuit, and means for closing the said circuit only in response to a plurality of groups of 'electrical impulses, and means for delivering such a plurality of groups of electrical impulses to said circuit closing means comprising a group of keys at a remote sending station, means for setting up a group of electrical impulses at said sending station upon the actuation of each key,- means for garbling said impulses in a constantly changing order, means for broadcasting `the garbled impulses by radio, and means upon the remotely controlled object for receiving and reversing the garbled impulses and transposing them to their original order for delivery to the said circuit closing means of the electrical circuit.
2. Apparatus of the character described for physically moving a dirigible body, comprising electrically energized actuating means for said object, a source of electrical power for said actuating means upon the object, an electrical circuit in which the source of power and said actuating means are included, a circuit closing member for said circuit, and means for actuating said circuit closing member comprising a bank of keys at a distant station, means for setting up a group of electrical impulses upon the Iactuation of each key, radio transmitting apparatus to which said impulses are delivered, means for changing the order of the electrical impulses delivered from any given key upon each successive actuation of said key to thereby garble said impulses, radio receiving apparatus upon said dirigible body, and a degarbling mechanism upon the dirigible body receiving the garbled impulses from the radio receiving apparatus of the dirigible body and restoring them to their original order, and means for delivering such restored impulses to the first-named circuit closing member.
3. A structure as recited in claim 2, wherein said circuit closing member is responsive only to a plurality of such degarbled impulses.
4. A structure as recited in claim 2, wherein said circuit closing member comprises a plurality of circuit closing parts arranged in series, the said circuit controlled thereby being closed only when all of said parts have been moved to circuit closing position.
JOSEPH B. WALKER.