US2536474A - Blind flying trainer - Google Patents

Description

Jan. 2, 1951 L. R. SUSDORF 2,536,474

BLIND FLYING TRAINER Filed April 16, 1941 4 Sheets-Sheet l cmzmam FALLS i INVENTOR.

BY W- ATTORNEYS Jan. 2, 1951 I SUSDQRF 2,536,474

BLIND FLYING TRAINER Filed April 16, 1941 4 Sheets-Sheet 2 lgiillraill4L- iliaziilll5: 1,!

INVENTOR. ZZOYZ? 75" 505.50???" ATTORNEYS Jan. 2, 1951 L. R. SUSDORF BLIND FLYING TRAINER 4 Sheets-Sheet 3 Filed April 16, 1941 INVENTOR. 1(0)) E 50530737" 6%; M A TOP/V575 Jan. 2, 1951 L. R. SUSDORF 2,536,474

BLIND FLYING TRAINER Filed April 16, 1941 4 Sheets-Sheet 4 INVENT OR. 11073 B Sl/SDOEF' Patented Jan. 2, 1951 UNITED STATES PATENT OFFICE 7 Claims.

Th'i-sinve'ntion relates to improvements in aviation training devices, and more particularly to an apparatus for training airplane pilots in the art of so-called blind flying wherein the pilot determines this position by the radio beani signals.

With the increase of interest in aviation and the establishment of more airports. it has been necessary to provide means and systems whereby in inclement weather it is possible for a pilot to find his way back to the airport or between spaced airports. It isa well known fact that often after a pilot has been in the air for a few hours the Weather closes in on him before he has a chance to reach his objective or return to his point of departure. Systems have been devised whereby he can locate and land at the airport in spite of the fact that there is little or no visibility.

The accepted system at the present time is to provide a system for sending out directional signals by radio which are picked up by the pilot and whereby from familiarity with their character he canorient his position. These signals commonly emanate from a so-called radio range station located subjacent the airport. The common practice is to have the station so designed and arranged that it provides a beam being a continuous tone which lines up directly with the airport. Should the pilot fly to the left of the beam, the character of the signal changes, and instead of the continuous note, he hearsthe internationalcode 1etterN comprising a dashfollowed by a dot. If he strays to the right or the beam t e signal changes to the code letter A being a dot followed by a clash. If the signal increases in intensity he knows he is coming into the airport: and if it decreases he knows that he is leaving. These signals are also interrupted periodically to' allow the identification letters of the particular beam" which the pilot is flying to be sent, which serves to tell him which beam he is on. Thesebearns do not necessarily extend east and west, and north and south, but are usually so arranged that they extend in the direction of the airlanes between the larger airports;

Usually, also, there are tw'o'beams' commonly called the east-West beam. and the north-south beam; These beams may divide the territory in about the field into quadrants, the character of which vary with different airports. For thepurpose of this descriptionthe quadrants will be considered as four and divided equally by an east-west beam and a north-south beam. The north-west and south-east quadrants off of the beam-then would be the l 'zones, and-thesouth west and north-east qu'adrants the A zones.

beam. This is effected by use of a se-eai-iee trainer \yhich'is or the fixed type and never leaves the ground.

One such trainer is used for teaching blind flying and is known commercially as the Links trainer and is substantially that disclosed in the United States patents to E. A. Link, Jr..- No. 2,179,668 of November 14, 1-939, and No. 2,119,683 of May 31; 393 8. In this trainer the ilot is seated in the cockpit or a device simulating an actual airplane and a hood is placed over his head; Connected to the trainer by a flexible cable is a so-called crab which travels over a chart. This crab travels according to the manner in which the trainer is directed and an observer or instructor watches the chart and the crab and sends signals to trainer, the nature of which is determined by the instructors observation of the position of the crab on the chart, and which signals are supposed to be of the type the flyer would receive if he were actually in the air and traveling over that part of the terrain represented by the crab on the chart.

Still other devices have been designed to edu cate the aviator to the art of blind flying. but they all more or less operate on the same general principle.

lthere are several disadvantages in these prior devices, the greatest of which is the reliance on the human element to inform the pilot as to his location; that is, it is necessary for an instructor to pay exact and close attention to the moveent of the trainee as indicated by the crab' or other devicei'n order to communicate the proper signals to the trainee. Should the instructor relax his vigilance, he inserts errors into theaction of the trainee by not changing his signals at the proper time. This rather thanhelping the trainee, results tohis detriment:

Still another disadvantage of some of these prior devicesis' the'elenient of cost. The cost of some of these devices is exorbitant and places the same beyond the hen ofprivate ownership. Not only is the cost a considerable item, but the cost of operation is not to be discounted since it is necessary to have an instructor present at all times and the possibility of a pilot training by himself without assistance is nil.

By the present invention it is possible to design a trainer for blind flying where the cost element is so low as to put the same within the reach of nearly any would-be pilots pocketbook. Furthermore, the device is such that it lends itself to refinements which thus make it possible to construct devices that have a minim-um number of parts and cost, and still retain a large measure of usefulness, or to make the more complex and complete devices having more refinements which aid inthe operation of teaching of blind flying and afford a still more realistic eifect to the training.

But what is most important even in its simplest form, the human element of the instructor is eliminated. The device isalso readily adapted to the operation of the trainers of the aforementioned Link type.

Still further in its simpler forms, it is an excellent educational device adapting itself to vari- 7 device for instructing aviators in problems of orientation in connection with blind flying.

Another object of the invention is to eliminate the necessity of instructors being present while trainees are learning blind flying.

Another object of the invention is to provide an improved means for sending signals to a trainee during blind flying instructions so that the signals are automatically sent to the trainee.

Another object of the invention is to simulate the signal sent out by a radio range station in and about an airport in a blind flying training device.

Another object of the invention is to provide a device for teaching blind flying that adapts itself to a game of skill and amusement.

Another object of the invention is to provide a device for teaching blind flying which is economical in construction and operation.

Another object of the invention is to provide a device which may be used in conjunction with existing devices to eliminate the error due to the human element in sending the proper signals to trainees in blind flying.

Still other objects of the invention and the invention itself will become more apparent from the following description of some embodiments thereof, which description is illustrated by the accompanying drawings.

In the drawings:

Fig. l is a plan view of one form of the apparatus of the invention;

Fig. 2 is a side elevational view thereof;

Fig. 3 is a sectional elevation showing the interior of the device;

Fig; 4 is a vertical section through a signal pickup device;

Fig. 4a is a plan view of the top of the pickup inner surfaces of one form of the device;

Fig. '6 is a view partly in perspective and partly :in plan showing the invention adapted to the so-called Link trainers;

Fig. 7 is an enlarged view of the recorder used in conjunction with the apparatus of Fig. 6;

Fig. 8 is a diagrammatic View of the electrical system embodied in the invention as shown in Fig. 1;

Fig. 9 is a side elevational view of a circuit breaking cam;

Fig. 10 is a side elevational View of a modified form of a circuit breaker;

Fig. 11 is a diagrammatic view showing the method of distributing the signals;

Fig. 12 is a schematic view of another modiflcation of the invention;

Fig. 13 is a plan view of another modification of the invention, certain of the parts being broken away to disclose the interior; a

Fig. 14 is a diagram of another modification of the invention;

Fig. 15 is a plan View of still another modification; and

Fig. 16 is a view taken on the lines l9-I9 of Fig. 15. 1

Referring now to the drawings throughout which likev parts have been designated by like reference characters and particularly to Fig. l.

Briefly, the invention comprises a signal generator which will generate on and off of beam signals so connected to a board or base that the signals are fed to this base in zones simulating the 'signal zones in and about an airport. That is, there may be the continuous tone indicating a beam designated as an east-west beam and another like signal indicating the north-south beam dividing the board into quadrants, the spaces between the beam being the off-beam signals of the letters N and A. Pickup means is provided associated with the base, which when moved about the base and into the various zones, picks up these signals much in the manner as an airplane would pickup the signals if flying near an airport. These signals are made audible to the operator through a set of phones or loud speaker, and he can thus accustom himself by the signals to directing his plane into the proper channels that will permit him to land his plane at the airport.

One form of the device is shown in Figs. 1 and 2 and contemplates a signal generator indicated generally at I, powered from the A. C. line and which may be of, any form usually an electronic 7 device, connected to the board or base indicated generally at 2 by a flexible multiple conduit 3. A suitable interrupter or timer is provided in the signal generator I to break the signal up into A and N signals and these signals are fed to the board as best shown in Fig. 8, all of which will be hereinafter more fully described. 'A set of ear phones l are also connected in the circuit and the volume of the signal may be controlled by the volume control 5 on the signal generator or by a remote volume control 6 stationed conveniently for the operator.

The base comprises an upper flat surface to preferably of a hard composition material such as pressed wood upon which may be imprinted a map, as best shown in Fig. 1, illustrating the territory around and adjacent to an airport. The upper board is held in spaced relation from the lower board H by sides i2 extending around three edges of the board; the fourth'edge remains left open to permit access to theinterior.

The undersurface of the upper board In and upper surface of the lower board I I, as indicated at I5 and i5 respectively are provided with a deposit of conducting material of relatively high resistance, which material is laid :onto the boards as best shown inliig. -5. Fig. :5 shows the top and bottom of the base takenapart and the top board laid over to the right so that it is upside- -down. The diagrammatic 'view in .Fig. 8 shOWS the top and bottom parts in the same position. The resistance material maybe a composition containing carbon, graphite or any other resistance orconductor material having a resistance, which material may be placed on the base by spraying, painting, lithographing or any other suitable manner. It may generally take theform shown in Fig. -5 wherein the boards are divided diametrically by pie-shaped segments passing through the center of the board in such a manner and so positioned that when the two boards are spaced together, the pie-shaped segments, which have no material thereon, are displaced on each board from the other substantially 90 As best shown in Figs. 8 and 5, the small circular area it at the center of the board usually is designated as the airport and in both parts is clear of any conducting material. The base II is clear of conducting material from the corner or from a space at H] extending from the lower left hand corner to the center l8, and from the center it to the upper right hand corner, as indicated at 2.3. This space may vary in width, but I have foundthat a path subtending an angle of substantially operates very efficiently. The remainder of the board on either side of this wedge-shaped division has applied thereto a compound, as previously described. One compound which I have found to be very useful, being a mixture of finely divided carbon and casein glue. In the drawings I have shown the greatest concentration of the material extending from a point indicated at iii to the airport point 53 and increasing in density as it reaches the airport it. This, however, is not strictly essential, as will hereinafter more fully appear, because the resistance decreases from the airport to the point 2! providing that the-conductors for transmitting the signals are connected to the board at 22 and did, as indicated in Figs. .5 and 8. For instance, the deposit could beof an even nature throughout the surface and the diminishing sig nal would be obtained merely by the increased resistance of the material with increase in distance from the airport 18. To provide it with portionsof increaseddensity, as shown, provides an exaggerated effect which is sometimes useful. As previously stated, the upper board is formed inthe same manner except that the various zones are 90 offset when the boards are placed in the proper position, the signal being connected to the upper board at tit-23a as indicated in Figs. 5 and 8. It will appear, therefore, that when the boards are in their proper position, the point of greatest density of resistance material on the upper board, falls exactly opposite the-completely non conducting portion of the lower board, and vice versa. Pickup means 25 isprovided for reciprocation inside of the base and in contact with the resistance material to pick up the signals placed on the boards. This, as best shown in Figs. 3 and 4, comprises a pickup base member 25 preferablyrnade of some heavy material to give it stability, and which may be of circular form.

The pickup base member is provided with a coupling 25 held thereon by screws 2? in which is journaled a crankshaft 28. Although I have designated the crankshaft 23 as being journaled in the coupling 2%, it willbe very obvious that the :member '30 by a coupling 3|.

crankshaft :doesvnot necessarily have to rotate in the coupling since the coupling and the base '25 may rotate with the crankshaft without having member 3! but preferably is a bar magnet, which :is of the permanentlmagnet type, many types of which are now :on the market and available.

'The member 25 is provided with an axial opening '32 to receive .a carbon brush assembly 33,

which extends and is held resiliently in engagement with the bottom surface i6 by a spring ti. The upper member 30 is provided with a similar brush 35 disposed ina socket 3t through the magnet, and held in spring-pressed relation by a spring 'il against the upper surface 15. .Electrical contactis communicated from the surfaces =15 and 16 :to the crankshaft and to the crank arm "38. The whole assembly, hereinafter referred to as .a pickup is movable about between the upper and lower base portions bythe control means and adapted to pick up signals that are fed into the base at points 2-2-2 3 from the material deposited-on the base portions.

As best shown in Figs. 1 to 4 inclusive, the control means comprises an operating handle 4i! which'may be a semi circular element, patterned generally after theelevatorand aileron controls for an airplane, secured to a base 4| which is hollow and contains therein a compass card 42, which is connected to a castor it. The castor 43 furnishes a support for the control, and has its pintle connected to the compass card. The castor rolls on the table it when the control is moved, and operates in a well known manner to rotate its pintle when the direction of movement is changed. When the castor rotates on its .p-intle the compass card moves also and indicates to the operator in which direction he is traveling. The pickup assembly is connected to a rod 45, the end of whioh is bifurcated at 46, Fig. :3, and has removably secured therein by pins il, aconnecting linkage for connecting the rod to the pickup. Theconnecting linkage comprises aflat portion-d8 for insertion in the bifurcated end of the rod, secured by pins 4-1. From the flat portion extend upper and lower branches id and an intermediate branch 58. The branches -49 and 50 are provided with aligned apertures through which is disposed the crank pin 38a. The intermediate branch as has a portion 58a which extends beyond the center line of the crankshaft and has connected thereto an electrical conductor 5 I.

The operator normally takes his position with the control handle is disposed between him and the base, the whole assembly being placed on a suitable benchor table M. It will thus be seen that if the operator is moving the device toward him,-0r to the left as viewed in Fig. 2-, the crank pin 38a is then closer -to the operator tha the shaft 28 and the magnet with its north and south poles will have the north pole pointing toward the operator, as also indicated in Fig. 4, and the castor '43 will be pointing away from'the operator, as shown in Fig. .2. Movement of the control device is preferably done in parallel lines; that is, the connecting rod fili is maintained in a north and south directionatall times so that the movement of the pickup is exactly the same amount 'of movement of the control handle 49, whether it be toward any point of the compass. I contemplate the use of a linkage which will prevent the movement of the control rod in any direction other than in parallel lines such as is illustrated in Fig. 13.

Disposed n the upper surface of the base is a miniature airplane 55, best shown in Figs. 2 and 3, the base of which comprises a' permanent bar magnet 5% having north and south poles, as. indicated. The attraction of the magnet member 3.0 for the magnet 56 on the airplane is sufficient, so that when the pickup member is moved about underneath on the board, the airplane follows, remaining directly above. That is, the south pole of the pickup magnet attracts the north polt of the airplane magnet, which north pole may be the nose of the plane, and the south end the tail. The plane then, if traveling in the direction indicated in Fig. 2, is headed south. If the control it and the'rod 45 should be moved laterally to the left, as shown cause the crankarm is also rotated clockwise 90 rotating the magnet 36] therewith. The pickup can thus be moved about between the upper and lower'parts of the base and no matter where or in what direction it is moved, the airplane will always be headed in the direction of travel and closely follow the position of the pickup. 1

{hr purposes of training, an opaque screen is provided, indicated at 6!, supported by a base 62 and having an opening 63, to permit free movement of the rod 45 ,therethrough, and still to screen the board and the airplane from the operator.

The signal generating means, as best illustrated diagrammatically in Fig. 8, may include a vacuum tube oscillator, although very obviously any kindof high frequency audio tone gencrating means such as a buzzer may be substituted,' which generates a note of approximately 890 c. p. s. The oscillator in Fig. 8 is designated CS6. and the output level is regulated by the volume control shown diagrammatically at 6. As previously stated this be a dual control, one on the oscillator and;

one remotely controlled by the operator. The output of the oscillator is fed through the leads 5% and El, the lead t'l connecting directly with one of the ear phone leads and the other ear phone lead 5| connected to the pickup 25; the other lead 66 goes to a circuit-breaker compris ing a motor 69 connected to gear reduction drive ,in Fig. 9, the rotor which may rotate clockwise is provided'with a cam surface on its side adja cent its periphery comprising alternately raised and low portions, Tiia being a high portion extending around one-third of the periphery of the cam and flush with the side'thereof; this -is followed immediately by a low portion lib extending one-sixth of the periphery of the high spots Na and Ho of the cam. Since Ho precedes Ho and is larger than Hc, it will be seen that this is adapted to provide the dash-dot signal and is larger than llc. The signal from the line 66 therefore goes throughthe brush 66a, thence through the cam H which is connected by the sliding contact 12a to the conductor 72. The conductor branches at 721) into two lines which are connected through the variable resistances Hi to the conductors l5 and 15a, which conductors connect to the points 22 and 22a on the board H. The volume controls or resistances i l permit the signal fed in either section of the base to be increased or attenuated at will. .When the contact arm 56a rides ofi of the high spot of the cam Ha to the low spot lib, this arm then contacts with the contact arm 53a which is connected to the. line 13. At this time neither one of the arms 56 or 1341 are in contact with the cam, and a current flows from the line 66 through the arm 66a to the contact 13a and thence to the line 13. Here it divides into the branches 73b and is sent through the lines i3b, through the variable resistances l5, and the lines I! and 'ila to the top board l5 where it connects to the conducting material at 23 and 23a. By reference to the diagram in Fig. 11 it will be noted that the signals N and A are alternately put out into the two lines 12 and 13 from the line 66 to which a continuous signal is furnished by the cam 1!. That is the dash goes onto the line 12 followed by the dot onto the line it, and in turn is followed by the dot into the line l2'to complete the. N, and

then there is a space in the line i2 while the dash of the A is being putinto'the' line 13 which is followed by a space in the line 13 while the dash of the next N is being put onto the line '52 etc. It is to be noted that the cam H in Fig. 11 follows the'cam design of Fig. 10 rather than that of Figs. 8 and 9. The function is the same in either instance. 7 1y modified cam H where the cam surfaces for making the dots and dashes or on the periphery instead of on the side. In this instance the contact member a swings back and forth be-' tween the contact carrying arm 12a and 13a.

7 at the airport.

breaker, but the two described are relatively simple and economical in construction. 7

In operation, the oscillator being turned on, the operator places the head phones over his cars so that he can hear the signals, and takes his position behind the control member 40, grasping the same with his hands. He then adjusts the volume control to provide a suitable volume. In the initial stage of' the training in order to accustom himself to flying the beam, he canoperate the device and atthe same time, observe the actions of the airplane on the top of the base; The object, of course, is' the same as in actual practice, namely, for the. operator I to get onto the proper beam and land hisplane With the N signals being. fed

. intothe bottom board at 22 and 22a, and the A signals being intothe top boad at 23 and'23a,

Fig. 10 shows a'slightand the plane in the position shown in Fig. 1, he will be receiving an A signal; this being because the lower part of the pickup is positioned as shown in Fig. l and in Fig. as is indicated by the dotted lines at A, on the base I! and A on the lower surface lb of the upper board [B (Fig. 5). In this position the pickup receives the greatest signal from the A distributing zone because it is closest to the most dense low resistance carbon zone on the upper base portion it and receives hardly no signal from the N distribution zone because it is in a thin high resistance carbon zone, and also because it is partially overlapping the zone 19 where there is'n'o carbon and no conducted signal. A relatively strong A signal is therefore heard. This can also be better understood by reference to Fig. 11, where the oscillator is shown connected to 66 and the cam causes the signal components to be alternately distributed to the lines 52 and 1'3 as previously mentioned. IE5 and I6 represent the resistance of the upper and lower boards between which the pickup 25 moves. In the position A the pickup is receiving more signal from the line 13, and in position B the signal from both lines balances furnishing a continuous tone, while in position C the signal is stronger from line 12, and N is heard. Should the plane be moved to the position B, indicated by the dotted circle on Fig. 1, the pickup is then disposed, as can best be seen in Fig. 5, by the corresponding dotted circle B, in a zone where the signal is picked up in equal intensity from both the upper and lower conducting surfaces. Since the signals are equal in intensity: and since they are interlocked as best shown in Fig. 11, the signal represents a single continuous tone. This corresponds to the northsouth beam on the map. If the plane then continues east across the map to the position 0, as indicated by the dotted circles on Figs. 1 and 5; the lower part of the pickup, as indicated on Fig. 5, is in the N zone of greatest signal distribution density, while the upper part, as indicated on the upper board It} of Fig. 5, is in the zone is where no signal is picked up, and therefore the operator receives an N signal in the head phone. He knows then that he has gone from an A zone across the beam to N zone. As a matter of fact, the actual manner in which the flyer would be trained to handle this device would be considerably different, since in all probability, after he had got onto the beam he would merely turn to the right or left to see whether he was traveling towards the airport, or away from the airport which would be indicated by an increase or decrease in signal strength because the pickup would approach or travel away from the contacts 22 or 23 where the signal was fed into the boards, and having determined which direction the signal was coming from, he would merely cross the beam slightly until he picked up the N signal, and then get back onto the beam and stay on the beam until he arrived directly over the center of the airport, indicated b open space I 8, where there is no material and where once he reaches that spot there would be a com lete ces ation of signal. It in this instance represents the position of the range station. In actual flying he would probably, if the station was arranged as shown in Fig. 1 with the station west of the airport, approach the airport from the west, and when he arrived over the station or point of no signal, start his glide, which would bring him down through the bad conditions until he was able to land his plane.

The figure of the drawing happens to depict the Cleveland Airport, but the boards can be arranged to depict any airport, and in most instances, it is possible to use the same base construction, and merely substitute different sectional maps for the different airports. These maps may be held in position by suitable clips.

In event that an airport should be selected where the beams do not run directly north and south or east and west, then the beams can be swung by changing the resistances i l and 15 in the N and A legs from the distributor. For instance, taking the N leg as in Fig. 8, if the resistance in the lines l5 and 35a is decreased, while the resistance in the lines T! and "Ila is increased, it will have a tendency to widen the N zone and narrow the A zone. It will also be seen that if the one of the resistances M in the legs '55 and 15a is increased, and the other decreased. while in the other the lines 71 and Ila the resistances 15 are likewise increased and decreased, there will be a tendency to shift the beams, depending upon the amount of change of the resistance, a considerable number of cornpass degrees.

After the operator has accustomed himself to the operation, and what happens by observing the same visual y, the screen 63 is interposed between him and the board, after which the board may be moved relative to the operator and the screen, the o erator holding the control handle steady while the moving is being accomplished. By moving the board around, the pickup and the plane on top of the board is placed in any zone that the instructor so desires. The operator then does not know where the pickup and plane are, and therefore has to orient himself entirely by the sound of the signals.

In Fig. 6 I have shown another modification. Here the oscil ator l is connected to the base 2 in the usual manner. The trainee, however, takes his position in a trainer 86 which may be of the aforementioned Link type, and wherein the hood is placed over the cockpit, as is common practice. The Link trainer is connected through a flexible conduit 8| through the side of the base to a crab which operates between the top and bottom boards of the base. The crab may be constructed substantially as shown in the aforemen tioned Patent No. 2,179,663, and per se, forms no particular part of the present invention other than as is particularly pointed out hereinafter. Movements of the crab between the board from the Link trainer are accomplished in the manner well known and described in that patent. However, in previous devices it was necessary for an instructor to watch the movements of the crab and transmit to the trainee signals indicative of his position as shown by the crab on the chart. In the present instance, however, the crab may be provided with a pair of pickup members constituting brushes riding on the surfaces l6 and E5 of the base, which brushes pick up signals from the base in exactly the same manner as the manually operated pickup previously described. lEhe upper pickup may have associated with it the bar magnet 3!], and a sma l airplane 8i travels about the upper surface indicating the position of the crab between the boards in a manner exactly similar to the device shown in Fig. .3.

It will thus be seen that the human element of an instructor whose attention might waver momentarily and thus provide the wrong signals to the trainee, is completely eliminated because his position is relayed to him automatically by the pickup on the crab between the upper and lower portions of the base. The airplane El travels over the top surface and follows the crab in the same manner that the airplane 55 of Fig. 3 follows the manually operated pickup.

As best shown in Fig. 7, a modified airplane Sl may be provided with an inkpencil 94 having a reservoir for receiving ink, and a stylus S5 for tracing a path on the chart such as is indicated at $6 in Fig; 6. This inkpencil does not necessarily have to be at the tail, but can be at the nose where the propeller is shown, but in either event, inks the path of travel taken by the airplane over the chart. As best shown, the chart is a removable sectional map held in place by clips 97.

In operation the trainee gets into the trainer, the hood is closed down over him, the instructor either opens up the base and positions the crab where he wants it manually, or reaches in with a suitable pole and moves the crab around to the proper position, starts the oscillator going, indicates to the pilot that he is now on his own, and the pilot works out his problem of orientation without further instructions from the instructor. It is thus possible for one instructor to supervise a considerable number of trainees and he can tell about the problem of each trainee by the course 98 traced on the respective chart. The pilots being trainedhave the signals relayed to them more realistically than they would if they were relying on the judgment of an instructor to inanua'ly see that the signals were sent according to what, in his opinion, would be the type of signals that would be received if the operator was in a particular zone,

Although I have not specifically shown it, it is contemplated that an addition in the oscillator setup be provided whereby the on and off beam signals are interrupted periodically during which period the station call letters are sent, as is the actual practice with the regular range stations.

In Fig. 12 I have shown another modification of my invention wherein a dirigible motor driven pickup is provided which operates in a manner substantially the same as that described for Fig. 6. That is, the pickup will be motor driven to travel at a certain speed variable'between certain limits simulating the top and cruising speeds of an airpane. The pickup is provided with brush type pickups and signals are communicated to the operator by means of the head phones Al. The oscillator l is connected to the board in a manner previously described to furnish the signals in the N and A zones. A screen 63 is a so provided to screen the board from the operator and the airplane operating on the top of the board may have the ink stylus 94-435 as shown in Fig. '7. Connected to the board by a cable I513 is a control box l5i which is provided with a control lEZ simulating a throttle whereby the speed of the airplane. can beincreased or decreased, as previously mentioned. This control may be eliminated in some instances and the pickup constantly driven at one predetermined speed. At 53 I have provided a stick similar to that employed in the control of an airplane for enabling the operator to bank to the right or to the left, and the operation of which when moved to the left or right as indicated in the dotted lines will cause the airplane 87 to train to the left or right.

It will be seen that this device operates in a manner quite similar to that of Fig. 6 except that the so-called Link trainer is eliminated.

In Fig. 13 I have shown another modification of my invention. Here, instead of the upper and lower boards being provided with a carbon deposit as in the manner of the previous figures, I have provided prepared surfaces which are both disposed in the same plane which may be the base. terial may be the same as that described, the pickup arm, however, comprises the contact portions use and it: held in a spaced relation from each other by a beam I62. The zones of resistance material are indicated by H! and Ill], each being divided by thepie-shaped segments H9-|2il and 9a and [20a respectively; those on the part Hi! being displaced 90 relative to those on the part III.

zones ill and lit respectively at the points l22l22a and i23-l23a in the same manner as that illustrated in the preceding figures. The pickup l0!llfil is shown in the position where the letter A is being picked up. The position of the airplane is indicated by a continuation of the rod 45 which extends beyond the beam H12 and carr es on its end a magnet to attract an airplane disposed on a chart similar to that previously described. The connection to the magnet may be through a member similar to the pickup shown in Fig. 3, except in this instance no brushes may be used because the signal is picked up by the pickup lii@lfll; the magnet in this instance is preferably directively moved by a castor and pintle.

In this embodiment I have shown a linkage which causes the controls to be moved in parallelism with the base. In the form shown it comprises a saddle E38 securely connected'to the rod 45 and extending down through an elongated slot l3l of a yoke I32. The saddle 538 is of sufficient length so that it cannot turn in the slot l3! and can only slide longitudinally therein. The ends of the yoke i392 are provided with extensions I33 which carry at their extremities guide tubes I 34 slidably journalled on rods I35 connected to the inner and far side of the base and in closely spaced paralleli m with the sides. graph mechani m could be substituted and a similar result accompl shed, as will readily be reco nized. The operation of the device is substantially the same that shown for Fig. l.

I also contemplate eliminating the top board and leaving the mechanism all exposed. In this instance, the chart would also be mounted on the bottom board, and the magnets for moving the airplane couldbe eliminated s nce the airplane would be connected directly to the castorpintle. This parallel linkage just described can also be applied to the device. of Fig. 1.

Although I have shown. and described my invention as operating with a relatively high resistance conducting mater al such as a 'mixture of carbon depo ited as described, I also contemplate using other types of means for distributing the signal, which can be either in-' The manner of deposition of the ma-' Signals are fed to the A suitably constructed pantoaseaen manner as the pickup of the previously described pickup. A suitable amplifier may be pro vided for boosting the signals the head phones l, should it be necessary.

In Fig. 15 I have shown an arrangement for accomplishing the objects of my invention capacitively. In this instance the signal is fed to metallic plates 2'53 and Zlila and 272 and H202. These plates are formed in plan view in the manner shown in Fig. 15 and are dished, as best shown in the elevational section of Fig. 16. The plates are held, being spaced from each other by dielectric partitions 2i and 292 which are parallel to each other. The pickup may comprise a pair of plates of circular formation .263 which slide between the dielectric plates 2c! and 202 and vary in their capacitive relation to the plates H3 and 272 according to their position relative thereto. The signals are fed to the plates in substantially the same manner as previously described for the inductive coupling and are picked up by the pickup 2il3.

It will thus be seen that I have provided a device that will enable an unexperienced person to soon accustom himself to flying on a radio beam. The expense of operation is practically negligible and at the same time the results of the operation more nearly simulate the actual conditions encountered on a radio beam than devices heretofore known. It will also be apparent to those who use the device how it may not only be used as a most practical training device, but also lends itself to various forms of entertainment for both the old and young, besides increasing the interest in aviation.

It will also be apparent that the device lends itself to various degrees of perfection, making it possible to construct inexpensive devices furnishing very satisfactory operation such as described in Fig. 1, to the more expensive devices containing the motor drive pickup. It will also be clear that there is no chance for the error that might be otherwise injected into its op eration as is possible where an instructor must use his judgment as to the type of signal that the trainee should be receiving.

A though I have shown permanent magnets in the miniature airplane and pickup, it is quite practical to substitute an electromagnet in the pickup; in this event the airplane could be partially of magnetic material so that only the nose, for in tance, was magnetic and the crank mechanism for the pickup could be eliminated.

In the inductively arranged setup it may also be desirable to in ert iron cores in the signal coil. Obviously, the loud peaker or h ad phones could have sub tituted therefor a visual indicater, shou d it be de ired.

Fa ing thus descr bed my invention and some embodim nt th r of. I am aware that numerous and exten ive departures ma be made bv me therefrom without de arting from the spirit and scope o the invention.

I claim:

1. An a a at s f r t achi nd flying including a signal generator adapted to generate signals corresponding to the radio signals broadcast by an airport radio range station, a base comprising a pair of vertically spaced upper and lower members, the opposite surfaces between the upper and lower members in said base having deposited thereon a conducting material having a predetermined resis ance and arranged in zones. means connecting said signa1 generator to said conducting material, and pickup mean disposed between and movable between said upper and lower members and in electrical contact with said resistance material and adapted to pick up signals from said material, and means connected to pickup to render said signals audible.

2. An apparatus for teaching blind ,fiying including a signal generator adapted to generate signals corresponding to the radio signals broad cast by a radio range station for guiding airplanes, a base comprising a pair of vertically spaced upper and lower members, the upper surface of said base adapted to support a map depicting a portion of the terrain over which an airplane may travel, the opposite surfaces between said upper and lower members in Said base having deposited thereon a conducting material having a predetermined resistance and arranged in zones, means connecting said signal generator to said conducting material, and pickup means disposed between and movable between said upper and lower members and in electrical contact with said resistance material adapted to pick up sigmale from said material, which signals vary according to the position of the pickup relative to the resistance material on the upper and lower members and from the point of connection of the signal generator to said conducting material.

3. A device of the class described comprising a base constituting upper and lower spaced members, conducting mate-rial of high resistanc disposed on the opposed inner faces of said. base, said conducting material substantially covering said surface except for an intermediate point that is free from conducting material at a place adapted to simulate a radio. range station, the material on each of said opposed faces of said base being divided into two or more conducting sections by spaces free from conducting material in zones extending from said intermediate points across the conducting material and said space converging toward said intermediate point, said dividing spaces that are free from conducting material being offset on each face of said base relative to the other, a signal generator adapted to generate interlocking code characters, connectors connecting each of said conducting areas at edge of the place simulating the radic range station to said signal generator, and resistance means interposed in each of said connectors to said conducting zones and controllable to control the intensity of signals fed to said zones, pickup means movable between the inner faces of said base portion and having means to pick up signals from said conducting surfaces, and means for directing the travel of said pickup between said surfaces, and means disposed on the surface of said base operable by said pickup to indicate the path traveled by the pickup.

A device useful for training aviators in blind flying, comprising a signal generator for generating code characters such as are broadcast from a radio range station for guiding an airplane, a base formed to simulate an airport and the surrounding territory and comprising a flat upper surface adapted to receive a sectional map, a lower portion for said base spaced vertically from the upper portion to provide an unrestricted passageway therebetween, the upper and lower horiaontal walls of said base having deposited thereon in a predetermined pattern a conducting material having a high resistance, said surfaces being substantially covered with said material and each of said walls having a path free from said material extending from the edge of the base to a pOl'tiOIl on the base selected to simulate an airport, the

sides of said path diverging from each other away from the simulated airport, the said paths on said Walls being displaced circumferentially from each other on opposite walls, said signal generator being electrically connected to said deposits to feed a signal of one type to the material on one wall and a signal of another typ to th material on the other wall; and pickup means movable between the upper and lower horizontal walls and having contacts for electrical engagement with the surfaces of said walls for picking up the signals fed thereto and means connected to said pickup to render said signal audible.

5. A device of the class described comprising a hollow base, conducting material of high resistance disposed on the opposed inner faces of said base, said conducting material on each face of said base being divided into two or more conducting sections by spaces free from conducting material, an intermediate enlarged space between said conducting materials, said dividing spaces that are free from conducting material being offset on each wall of said base relative to each other, a signal generator adapted to generat interlocking code characters and connectors connecting each of said conducting areas at the edge of said enlarged space to said signal generator and resistance means interposed in each of said connectors to said conducting zones to control the intensity of signals fed to said zones, pickup means movable between the inner faces of said base portion and'having means to pick up signals from said conducting surfaces, and means connected to said pickup and operable outside of said base to direct the movement of the pickup between said surfaces, and means to simulate a miniature airplane disposed on the surface of said base and having a magnet, a sec- 0nd magnet carried by said pickup and operable to cause the airplane to move with the pickup.

6. A device of the class described comprising a base constituting upper and lower spaced members, conducting material of high resistance disposed on the opposed inner faces of said base, said conducting material substantially covering said surface except for an intermediate point that is free from conducting material at a place adapted to simulate a radio range station, the material on each of said opposed faces of said base being divided into two or more conducting sections by spaces free from conducting material in zones extending from said intermediate points across the conducting material and said space converging toward said intermediate point, said dividing spaces that are free from conducting material being offset on each face of said base relative to the other, a signal generator adapted to generate interlocking code characters, connectors connecting each of said conducting areas at the edge of the place simulating the radio, range station to said signal generator, and resistance means interposed in each of said connectors to said conducting zones to control the intensity of signals fed to said zones, pickup means movable between the inner faces of said base portion and having means to pick up signals from said conducting surfaces and means disposed outside of said base and connected to said pickup and having a compass card for indicating the direction of travel of the pickup for directing said travel of the pickup between said surfaces, and a miniature airplane disposed on the surface of said base and having magnetic means magnetically attracted by a magnetic means carried to said pickup to indicate the path traveled by the pickup.

'7. A device useful in the teaching of blind fiying comprising a signal generator, a motor driven circuit breaker for breaking up the signal from said generator into code characters connected to the signal generator, a base, a, pair of surfaces on said base having a conductive resistance material coated thereon, each of said surfaces having a zone of non-conducting material dividing each one of said pair of surfaces into spaced conducting zones, said non-conducting zones comprising an intermediate area for simulating a radio range station and diverging areas extending therefrom, the non-conducting spaces of each of said surfaces being radially displaced relative to the intermediate non-conducting zone, and pickup means having brushes for traveling on said surfaces, a rod connected thereto and extending beyond said base adapted to be moved by an operator, and a linkage connecting said rod to said base to direct the movement of said rod along parallel lines, and means connected to said pickup to render signals picked up by said pickup from said conductive material intelligible.

LLOYD R. SUSDORF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Air Corps News Letter, vol. 21, No. 6, March 15, 1938.

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