Патент USA US2118929код для вставки
l May 31, 1938. E KFMMMQl ' 2,118,929 SLIP-WAY BEACON Filed March '7, 1935 67 R1 _ “â ß . £2 Í / 0( AP | Fw L a’ APatented May 31, 1938 2,118,929 SLIP-WAY BEACON Ernst Kramar, Berlin-Tempelhof, Germany, as signor to C. Lorenz Aktiengesellschaft, Berlin Tempelhof, Germany, a German company Application March 7, 1935, Serial No. 9,808 In Germany March 1, 1934 3` Claims; The invention is an improvement upon that disclosed in the copending patent application Ser. No. 722,470, ñled April 26, 1934:,` for System for landing aeroplanes. In this application, a slip 5. way beacon is described the essential features of which are that an additional signal is transmitted to the aeroplane as soon as this reaches the point where it should begin to descend, and that the landing is effected in accordance with the in 10 dication of ñeld intensity which the receiver shows at the moment of the reception of the additional signal. This method has the advantage that the receiver need not at the commencement of the flight be adjusted to have a predetermined sen 15 sitivity, but that it is quite insigniñcant what a sensitivity the receiver may have. The receiver should merely be of such a constancy that its sensitivity is not varied during landing, that is during the time which there is between the mo ment of beginning the descent and the moment of touching the ground. In order to decrease as far as. possible the ex penditure in apparatus, the additional signal will preferably be transmitted by wireless on the same 25 or approximately the same wavelength as is used for characterizing the gliding path. This path and the additional signal are differentiated from each other with the aid of different characteris tic tones. 30 The invention described hereafter proposes in this connection to polarize the two radiations diñ‘erently with respect to one another. In this v35 (Cl. Z50-11) in the necessity for operating with receiving antennas polarized essentially in the same man ner. The antennas. employed on the receiving side, which in most cases are dipoles, are in ac cordance with another feature of the invention Ul preferably connected With separate audion stages. In order that also on the receiving side the en tire arrangement become as simple as possible, one could intend to produce gliding path and ad ditional signal on the basis` of the same wave length and to distinguish between them by differ ent tones. One could intend also to ensure that the carrier frequencies for gliding path and ad ditional signal differ from each other slightly. This would result in the advantage that the con 15 stancy of the transmitters need not be so great as in the case of the same wave length. In this event, however, on the receiving side an input resonance circuit or receiver circuits would have to be employed, these circuits being so wide as to 20 allow the two carrier frequencies to pass through with the best constant efficiency. On the other hand, however, the superposing-tones of the transmitters must be considerably higher than the characteristic tones. This method would require 25 the least expenditure on the receiving side, if the transmission energy and thus the intensity of the receiving field are very great, In practice, however, it is for several reasons sought with re spect to the transmitter side to be successful with 30 way, above all a considerable simplification of the entire arrangement is attained on the trans mitter side. the aid of means as simple as possible. The de scribed method may then happen to be insuffl cient. In view of this possibility, the invention further proposes to provide separate audion stages in the receiver. This has the advantage For the gliding path a vertical polarization is employed, in order to create a good slip-way guide by means of a simple antenna arrangement of sharply tuned circuits in employing back cou pling or dispensing with attenuation, a method comprising, for instance, a dipole continuously that in the case of a wide resonance curve can of 40 fed by a high-frequency generator, and two re flector dipoles keyed alternately. This is espe cially so if a dipole, fed continuously, and reflector dipoles are disposed in a position so high above the ground that a propagation curve suitable for 45 the gliding path is obtained without additional devices being requisite. If according to the in vention a horizontally disposed dipole is em ployed for the additional signal, then a disc shaped radiation is attained without the aid of 50 additional means, namely a radiation vertical to the direction in which the aircraft is moving, provided that the dipole is located in this. direc tion. The application on the transmitter side of these different polarizations results on the receiving side 10 that each carrier wave can be received by means course not be adopted immediately. The low frequency may then be gathered at a place after the audion, so that also here the expenditure on the receiving side will not be especially great. The invention will be more fully explained in the following description taken in conjunction with the drawing in which Fig. 1 shows the gliding path in a horizontal section, Fig. 2 in a vertical section and Fig. 3 the appertaining re ceiving arrangement. l In Fig. 1 the landing ground is indicated b AP. The gliding path is obtained by a trans mission arrangement consisting of a continuously energized vertical dipole D and two alternately keyed reflectors Rl and R2. Two shifted ellipse diagrams are alternately eifective, said diagrams 2 2,118,929 are blended into a zone of equal field intensity in the connection line of the two points of intersec tion, which is marked as angle a in the drawing and which indicates the flying direction for land ing, to the pilot. The radiation is vertically polar ized. The transmission arrangements for the presignal are provided in a distance d from the landing ground. The radiation is horizontally polarized and is generated by a dipole DI ar ranged in the landing direction. A disc-shaped radiation diagram in the form of SI is effected vertically to the flying direction. Fig. 2 represents a gliding path method in the vertical plane and marks the landing ground also with AP, the Vertical dipole for the gliding path pli?led in the high frequency ampliñer H, rectified inthe audion part Al, ampliñed at low frequency in the member N and conducted to the indicating instrument J or the telephone T respectively. The horizontally polarized signals are received by means of the horizontal dipole E2, rectiñed in the second audion part A2 Vand conducted to the common low frequency amplifier N. What is claimed is: ì 1. In a slip-way beacon wherein the point at 10 which the descent for landing should be com menced along a gliding path'is indicated to the aircraft by an additional signal transmitted by wireless, the method of aiding the landing of air - craft which comprises transmitting vertically radiation with D and the horizontal dipole with DI. The gliding path curve GI, G2 and G3 are polarized radiations for the gliding path and transmitting horizontally polarized radiations for lines of equal field intensity of the vertically polarized gliding path radiation and the diagram` rection of landing of said aircraft. 20 Si represents a horizontally polarized signal. The airplane approaches e. g. at a height h, ascer tained by means of the barometer-altimeter and intersects. the radiation of the presignal Si. The pilot knows thus that he may initiate the landing and flies e. g. on the curve of constant field in tensities Gl. ' Fig. 3 shows the receiving arrangement. The vertically polarized gliding path radiation is re ceived by means of a vertical dipole El, is am the additional signal in a plane normal to the di Y 2. The method of landing aircraft according 20 to claim 1 which includes the steps of separately detecting the gliding path signal and the addi tional signal and thenV impressing Vsaid detected signals upon a common signal amplifying path. 3. The method of landing aircraft according 25 to claim l, wherein approximately the same wave length is employed for both radiations. ERNST KRAMAR.