Патент USA US2407175код для вставки
Sept» 3, 1945- P. oRLlcH 'ETAL 2,407,175 ECHO SOUNDINCT DEVICE . Filed Nov. 14, 1940 3 Sheets-Sheet 1 4/ 4/ :YI /1 \ 1%, \\\\\\\ \\\ _ww w , o //ß M9 l / ffy 4. ` u ' _nvm-„foes A57-¿1e @e4/ch’ GMW-Hf@ /Vfazz -, HANS Merz. 5y M SePt- 3; ‘1946- ' P. oRLlcH Erm. 2,407,175 ECHO soUNnING DEVICE Filed Nov. 14, 1940 ì » s sheets-sheet 2 Sept. >3, 1946. „ P, oRLlcH' Erm. 2,407,175 ECHO SÓUNDING DEVICE _ Filed Nov. 14, 1940 ' . G '00 ` 3 Sheets-Sheet 3 Patented Sept. 3, 1946 2,407,175 UNITED STATES PATENT OFFICE 2,407,175 ECHO SOUNDING DEVICE Peter Orlich, Günther Negel, and Hans Hartz, Kiel, Germany; vested in the Alien Property Custodian ` Application November 14, 1940, Serial No. 365,646 In Germany May 2, 1939 3 Claims. 1 . 2 > This invention pertains to sound-emitting de vices of the kind operated by a compressed gas, invention the tuning is achieved by making the greatest distance between the openings and the such as whistles and sirens. Some features of the invention are particularly concerned with Walls of the air chamber equal to an uneven multiple of one-quarter of the emitted wave the emission of signals for echo sounding devices. Cil length. Referring first to Fig. 1 of the drawings, I5 is One object of the invention is to improve the an air chamber of a siren having a rotor I1 and efficiency of sound-producing devices of this kind. ' Another object, pertaining especially to sound emitters for aircraft, is to provide a more com driven by a motor 2|. The air chamber is sup plied With compressed -air by an inlet nipple 3|. pact construction and one which enables the 10 Inside the air chamber is a differential valve 24, known per se, the valve surfaces ‘I and 8 of which sound emitter to be integrated with the structure of the aircraft. ' Another object is to improve the operation of the valve controlling the sound emission. Another object is to improve the synchroniza „have different areas and rest upon corresponding seats of the air chamber. The differential valve is held in closed position by an electromagnet 9. However, due to the diiîerences in the respective areas Vof the two valve surfaces, upon opening of tion of the signal emission of an echo sounding the magnet circuit the valve is released and is device and the start of a measuring apparatus moved by the compressed air in the direction for determining the time interval between the indicated by the arrow. Thereby the air in the signal emission and echo reception. Another object is to reduce the liability of the 20 chamber can flow out through the openings I6 sounding apparatus to be disabled by becoming and I 8 of the stator and the rotor I‘I, respectively. This construction is particularly adapted for iced. sirens used for echo sounding devices built into Another object is to provide an improved gov aircraft and intended to emit intermittent sound. ernor mechanism suitable for, though not limited In accordance with the invention. the air charn to, use on the rotor of a siren or its driving motor. 25 ber IU is adapted to the sounding frequency by Other objects will appear from the following making the distance between the openings IG and specification, in which several illustrative ern the upper end I2 of the air chamber an uneven bodiments of the invention will be described, with multiple of M4. In this connection it is impor reference to the accompanying drawings, wherein Fig. l is an axial section of a siren embodying 30 tant that especially in those cases in which the inner walls are constituted by the armature of a differential valve, the valve surfaces at I2 con Fig. 2 is an axial section of a modification of stitute as large a fraction of the end surface as the inventive siren, together with its _driving possible and the curved zone I3 is kept relatively motor and compressor, in an arrangement illus small, so that the tuning can be carried out in a trating several features of the invention; clean-cut manner. In cases in which it is not Fig. 3 is a whistle sound emitter, with asso necessary to produce such accurate tuning, itis ciated compressor and driving motor; and . preferable to give the air chamber a strictly cy Fig. 4 is an axial section of part of a motor lindrical shape, with flat end faces. In all cases showing a governor mechanism in accordance 40 the relations vare best secured if the air chamber with the invention. is at any rate made in the form of a solid of Sirens have an air chamber which is inserted revolution. in the compressed'air supply line just in front If the outer walls of the air chamber are not of the outlet openings of the rotor, in order to straight as in the example, but are to la certain produce a uniform flow of air. Such an aircham ber is used in all kinds of sirens, including those' 4.5 degree curved, as indicated by the dash line I4, features of the invention; the straight line distance from the openings‘IB to the end faces at I2 is not the criterion for determining the Wave length, but rather the a cylindrical surface, as well as those whose open ings are in a disk. length of the shortest curved connecting line According to the invention the efficiency of 50 between said openings I6 and said end faces at I2. such sirens is considerably improved by tuning It is important in some cases to design the siren the air chamber to the emitted frequency. This for two or more operating frequencies, as in the driven pneumatically as well as those driven by a motor and likewise those whose openings lie in tuning causes stationary air waves to beset up with a loop at the openings and a node at the case of the air protective sirens. In such cases there may be used either a plurality of passages most remote wall areas. In accordance with the 55 for the air stream within the air chamber, one 2,407,175 3 4 example of which would be a smooth cylinder and the other a curved conduit, for example, a spiral channel; or the air chamber can be tuned to a common multiple, for instance, the least common multiple of the two signal frequencies. So, for example, a siren with frequencies of 1800 caused by the spring action of the air compressed in the air cushion. These axial vibrations cause a repeated closing and opening of the diiîerential valve so that the true sound signal is mislead ingly interfered with by these vibrations, whereby the desired signal is furthermore unnecessarily and 3000 cycles 4per second can be used if :its air chamber is tuned to three-fourths of 1800 cycles or with five-fourths of 3000 cycles. measuring elevation above ground, the danger In order to utilize the good properties of thecompressed air-operated sound emitter in accord exists that the echo» coming in may go into the outlets of the sound signal emitted. This disad ance with the invention to the full extent, it is advisable to connect the sound emitter with a ring-shaped horn; for it has been >shown that other horn shapes allow sub-maxima of the di rectional characteristic of the» sound emitter to occur, which are perpendicular to the main'direc vantage is eliminated by providing in the part of the enclosing wall 25 of the stator which is parallel to the valve plate 25, bleed ports 28 in tion. In the use of such devices an erroneous indication was given because at small heights they path of the direct sound beam between the sender and receiverand the path ofthe reflected sound beam are almost the same; that is, in the use of the sound emitter with a tuned air chamber, the advantage achieved is nullified by the use of an unsuitable sound horn. It is particularly advan tageous for benefit of thesound characteristics to construct the ring horn of the sound emitter as a so-'called exponential horn7 that is a horn extended. V~If such devices are used as a sound emitter for air-sounding devices or devices for suitable number and size to weaken the cush ioning eiIect to such an extent that the air cushion does not act as a spring upon the valve, so that the valve is not set in vibration. Heretofore the compressed air for driving a siren, or whistle, of an air sounding unit has been either taken from a compressed air container, such as a steel flask, or it has also been suggested to use the exhaust gases of the aircraft. The use of exhaust gases, however, has the disadvantage that the superatmospheric pressure which is available is much too small, to produce the loud sound impulse required in practice. The use of a steel flask has seemed up to now the best means of supplying the compressed air, although it al tially. along its length. The construction of the 30 ways had the disadvantage that it had to be ex sound horn as an exponentially expanding ring changed fro-m time to time and a relatively long horn has an additional advantage; the motor compressed air conduit was required. An im used to drive .the ~rotor of the siren can be built portant improvement of the whole signal emitting into the Ainner space of the inner horn. Thereby apparatus of an air sounding unit is now pro the whole `sound emitting unit is reduced to a vided, by producing the compressed air by a com small height. Furthermore, it is thereby possible presser which is arranged in the immediate vi to build the'sound emitter into a part of the body cinity of the sound emitting apparatus. By this of the aircraft, for example, into its deck. Since means not only -is there an important saving of for aerodynamic'reasons the outer surface of the space and weight, as against the known units aircraft must be smooth, the sound emitter is 40 operating with a steel flask, and the exchange of brought 'into the inside of the part of the body the steel?lasks done away with, but in addition of the aircraft on which it is mounted, such as to that the following advantage is achieved: It the'fuselage. This, however, requires a break in has been found in the operation of echo the static vframe of the fuselage. It is therefore sounding. units on aircraft that a difficulty oc important to build in the sound emitter in such curred in unfavorable weather conditions, caused a way that the outer horn constitutes a stress by the icing of the transmitting device, as a re sustaining unit of the aircraft fuselage. This sult of which in whistles the Whistle openings were manner of building in the unit is, furthermore, closed and in sirens the rotor was frozen fast. suitable for all kinds of shapes of horns, so that This dan-ger occurs above all in echo sounding it constitutes a distin'ct'feature of the invention 50 devices used for landing purposes and therefore in itself. usually having a measuring range of only one Fig. 1 exemplifies the latter construction of hundred or a few hundred meters, because these the inventive siren. The air currents ñowing devices are not operated constantly, but are set out of the ports í S and >I8 flow into a sound horn, in operation only shortly before the landing. By whose cross-sectional area increases exponen which consists of an outer horn wall I9 and an inner horn Wall 20. These two horn walls are . producing the'compressed air by the use of a com pressor near the sound emitter, the compressed cf exponential form, In the hollow of the ’inner horn 20 is lodged a motor 2l which drives the air is supplied at a temperature much above the atmospheric temperature. The compressed air rotor. supplied by the compressor'necessarily has a tem The outer horn I9 is constructed as a stress-sustaining part of the aircraft fuselage and merges with the outer ‘wall of the fuselage perature of about 100° C. or more. Now if care is taken to avoid any substantial loss of heat on the way from the compressor to the sound emitter it self, the whistle or siren is pre-warmed. The pilot 4|. In front of the opening of the horn there is preferably stretched’a screen or diaphragm 23. Fig. 1 also shows an additional improvement of can therefore switch in the sounding apparatus the sound emitterof an echo vsounding device in 65 »a‘few minutes before the landing,l if he knows or accordance with the invention. Since the axial forces and accelerations occurring during the movement of the diiïerential valve 24`provided in the air chamber to produce very short sound impulses may become too largeand lead'to injury of the’device, there is enclosed between the 'valve plate 25 next to the outlet ports and the enclos ing wall 26 of the air chamber, an air cushion 2l. This device, known per se, h'as the disadvantage fears'that the transmitter may have become iced, and thereby can thaw it out. In >the arrangements known heretofore, which used the exhaust gases of the motors as an op erating medium for the siren or the whistle, it is true that gases of elevated temperature were used; however, as previously indicated, such de vices have rnot proven to be useful in practice. An additional advantageous arrangement of that the valve has imparted to it axialvibrations 75 the echo sounding apparatus in accordance with 2,407,175 6 the invention consists in driving the compressor as well as the rotor of the siren by one and the same motor; that'is, a motor is used for driving the compressor, which kis required for other func tions on the aircraft. In this way the arrange ment of a special motor and thereby an increase in the weight and space requirements are avoided. between the motor 'I1 and the rotor 19. In this case, to be sure, it is necessary to provide a speed regulator for the compressor motor. ‘ ` A special form of the inventive conception consists in the use of a pump and impact mech anism as a compressor, which commends itself particularly for use in air sounding units on ac This advantage is naturally also achieved if the compressor is operated directly by the aircraft count of its compact construction and small space requirements. In Fig. 3 is shown a sound emitter of an air motor. Such a device is desirable for the use of a 10 whistle as the sound emitter. sounding unit in accordance with the invention, using such an impact mechanism compressor. In Fig. 2 there is shown an illustrative embodi ment of such a device. 11 is a driving motor 95 is a whistle, which is separated by a check which drives the rotor 19 of a siren through a valve 96 from a compression chamber 91 enclosed step-up transmission gear 18 and a compressor 15 by a cylinder 91a. Within the compression chamber reciprocates a piston 98 against a spring 8| through a reduction gear 80.` The transmission 99, the reciprocation being caused by means of gear 18 is connected by a shaft 82 to rotor 19 not rigidly, but through an elastic coupling 83. Also a cam |00, which is driven by a worm wheel |0| operated by the worm I0|a of~ a motor |02. An there is mounted on the hollow shaft 84 which connects the elastic coupling “83 with the rotor 20 additional check valve |03 serves for suction of the atmospheric air into the compression cham 19, a centrifugal governor 85 providing for a con ber 91. A switch |04 arranged in the compres stant rotary speed of the rotor 19. 86 is the inner sion space is adapted to control the time measur wall of a ring horn set in front of the outlet ports ing mechanism of an echo sounding device, not 81 of the rotor, the outer wall of the horn being indicated at 88 and being also of the exponential shown. Said switch |04 being pressure responsive can form. The elastic coupling 83 and the centrifugal beV connected, for example, with the measuringgovernor 85, which is advantageously constructed as a centrifugal braking governor, are arranged mechanisms of the kind shown in the copending applications of Peter Orlich and Hans Hartz, within the hollow-space 89 enclosed by the wall 86. From the >compressor 8_| the compressed air is 30 Serial No. 285,310, filed July 19, 1939, and of conducted through a conduit 90 into the tuned air Peter Orlich, Günther Negel, and Hans Hartz, chamber 9| of the siren. It is particularly ad Serial No. `365,647, ñled November 14, 1940, or Patent No. 2,032,893 to Bernhard Settegast and vantageous to construct the air chamber 9| in Wilhelm Rudolph. Measuring apparatus of this such a way, vas shown in thel example, that the whole, or atleast the greatest part of the shaft 35 type operate upon the principle of measuring the interval between the instant of emission of the of the rotor, is surrounded by it. Hereby the sound signal and the instant of reception of the uniform heating of the moving parts of the siren, echo. Accordingly, the measuring mechanism as well as all parts of the rotor, is accomplished. which measures this time interval must be set in Also upon replacement'of the siren by a whistle such a construction of the air 'chamber is desir 40 operation at the same instant as the signal is emitted. The emission of the signal is generally able. The inner wall of the air chamber 9| is repeated periodically and usually the signal formed, in known manner, by an electromagnet transmitter is set in operation by some kind of armature 92 serving as a valve for controlling the an electric device. Heretofore, the transmitter supply of air to the ports 81, and the air induc tion ports 93 of the compressor 8| are provided, , i and the measuring `mechanism have been simul taneously controlled by a control member, for in known manner, with am pressure regulating example, a shaft rotating at constant speed. In valve `94. rI‘he electromagnet armature 92 is practice, disadvantages of this system have oc shown again as a differential valve. curred which are due to the fact that electrical The length of the compressed air conduit 90 control'effected by means of relays or switches, and the heat insulation of the same are made to particularly mechanical switches or similar trans conform to the conditions prevailing in the com mitting members, is not absolutely exact and pressor 8|. Under certain conditions it is neces consequently no correct synchronism between the sary to provide the conduit 90 with heat insula signal emission and the setting in operation of tion, if this conduit is notaltogether eliminated, the measuring device is afforded. This disad and to arrange on the compressor 8| .itself cooling vantage is satisfactorily avoided by using said fins, so that on the one hand the temperature pressure responsive switch |04 automatically necessarily arising from the compressionof the actuated by the inventive sound emitter of Fig. 3 gases does not become too high and create a fire to set in operation the mechanism for measuring hazard, while on the other hand a further cooling of the air conducted to the tuned air chamber 9| 60 the length of time for the transmission of the sound. is prevented. >At very high temperatures of the It is obvious that the motors for driving the air, to be sure, and with the simultaneous use of rotor of the siren and the time-measuring appa good insulation of the compressor 8| against the ratus are to be kept at a constant speed. For surrounding conditions, it may be indicated to this purpose centrifugal governors are frequently cool the compressed air first on the outer wall used, in which a switch contact is closed under 1 of the air chamber 9|, whereby it is prevented the innuence of centrifugal force, this switch that the whole siren is subjected to excessive and controlling any part of the motor, either the field damaging heating after being thawed and the or the armature. In the known governors it is rotor set in operation. . The arrangement of the compressor, as well as 70 usual to provide a lever that also operates the the coupling of the sound emitter, is not limited switch contact, eccentric to the axis of rotation, to the form shown. Instead of the elastic cou so that centrifugal force acts vdirectly upon the pling 83, for example, any other non-rigid cou switch lever. This has the disadvantage, how pling can be used, for example, a friction cou ever, that the switch lever, on account of its ec-` pling._ It isv even possible to use a. rigid coupling centric position, forms only a chord within the 2,407,175 7 8 available circle, which -`defines-‘the .limits of 'the rotary-part ',of'the governor.` Consequently, the length of the switchlever in comparison with the dimensions of thefwholecentrifugal‘governor is is mounted upon the r.switch lever :I | I. The abil ity of the half l(ball ‘| |1 ‘toshift enables this ele ment .always :tofcon-form` uniformly to .the bear ingpoints of the 'ballsl |8. It is of coursegneces relatively smalh resulting also . in a relatively 5 sary to take care .that Ythe axis of symmetry of small extent of .moi/ement, which is furthermore the cause of arrelatively large irregularity. Now it-is'particularly desirable in air sounding appa the ball bearing .H8 and >the half Vball |.|'| ,is -as nearly as. possibleon‘the axis of rotation.. The above-described conception whereby the ratus according to the invention -to provide a disadvantages of .the previouslyknown centrifu switching movement .as -large as possible .for the l0 gal governors are removed is not limited .tothe givenA ltotal dimensions of the centrifugal gov illustrative form shown in Fig. 4. ernor Vand‘thereby'to .achieve the greatest ‘possible The elements of theinvention can obviously accuracyA of the governor, by constructing the be used .either 'individually or in any combina centrifugal lgovernor armas .a bellcrank lever, tion. the end point ofonezleg of which visarranged on 15 We claim: aîa'rocking axis :at the periphery of 'the rotating 1. In a siren, a casing enclosing `an'air cham housing or other carrier., and the free -leg of which ber, means for delivering compressed vair to said extends to the axis of rotation, wherefit acts upon chamber, said casing having ports for emitting anon-rotatingswitch lever. In contrast to the compressed air from vsaid air chamber, a rotor usual centrifugaly governors .the yswitch `is there- 2Q mounted adjacent said ports, and means for driv fore'stationary, in la centrifugal governor accord ing said rotor at a predetermined speed, said rotor ing to the invention. Forthis reason the gov having ports coacting with said casing ports to ernorisparticularly suited for regulating the ñeld` control the emission of compressed air from said of îamotor, because Aall >collectors are eliminated. air chamber to produce a sound of definite fre In Fig. 4 is shown an illustrative embodiment 25 quency, a valve seat and a vdifferential valve in of such Va governor. ||9 is the armature'of a said air chamber coacting to control the flow vof motor, which rotateswithin a >field frame |05. compressed air from said chamber to said ports, Upon the armature is a Vsupport |06, which re the armature of »said valve constituting an inner volves with it and :carries upon its periphery a wall of the .airA chamber and designed to recip pivot |01, about which a bell 4crank |08`is yroclr- 30 rocate in the direction of- ’its longitudinal axis, able. The leg of this bell crank |08 which is the configuration of the-armature being such as parallel to the axis Aof rotation is shorter than to form an outer curved surface defining a rela the other and isalso loaded with a greater'mass tively small curved Zone within the air chamber, than"V the other. Herebyit is aohievedthat both whereby said ai-r chamber is tuned to said fre the greatest possiblecentrifugal forcev and the 35 quency so that standing sound Waves are set up greatest‘possible switching movement of the 'free with a loop at said ports and a node at the end end of the bell crank lever |08 occurs. Opposite of said air chamber most remote from said ports, the vbell -crank lever |08 is symmetrically arranged the distance from said ports through said air a second bell crank lever |09, which is likewise chamber to the most remote part of the inner rockable upona pivot | |-0 at the periphery ofthe 4o wall of said casing being equal to an uneven carrier |05. By Vthe arrangement of two sym multipleof one fourth of the wave length of the metrical Acentrifugal governor :lever arms there yis emitted -sound waves. simultaneously provided la balance of the whole 2. In a siren, a casing enclosing 4an air cham system. This is, however, not absolutely essen ber, lmeans for delivering compressed air to said tial to ‘ the device. enough. One lever arm would be 4_3 On the other hand lobviously three or more lever arms could be'used, with- an increase chamber, said casing having ports for emitting compressed air from said air chamber, a rotor mounted adjacent said ports, and means for driv ing said rotor at a predetermined speed, said rotor having ports coacting with said casing _ports The free ends of Vthe bell crank levers ,|08 and , ,j to control the emission of compressed air 4from |09 act upon -a switch arm `| | |, which‘ismade as " said Aair chamber lto produce a sound of definite large as possible, that is, the rocking axis ||2 of frequency, a valve seat and a differential valve the switch lever is `>likewiseplacedat >the periph in -said- air chamber coacting to control the íiow ery of the governorand secured ,to‘ithehousing of compressed air from said chamber to said ||3 `of the governor. The housing ||3 forms a , .. ports, the armature of said valve constituting an unit with the frame m5V of the motor. At the U" inner wall of the air chamber and designed to free end of the switch arm |||`is a contact H4, reciprocate in the direction of Vits longitudinal the contact surface »of `which‘is fixed Yto any sta axis, the configuration of the armature being tionary part, preferably upon the housing || 3, ofthe centrifugal force, and‘thereby amore exact operation of 'the governor would be provided. such as to `forman outer curved surface defining and is perpendicular to the axis lof rotation. The switch arm ||| is held by a spring ||5 at aiden (il) a .relatively small curved zone within the air chamber, whereby, said air' chamber is tuned to nite normal distance from the contact face ||4. said frequency sothat standing sound waves The tension of the fspring ||5 .isadjustabla in are vset up rwith a. loop at >said ports ,and a .node known manner, by a setscrew H6, which ’ is at the end of .saidair chamber most remotefrom screwed into the :housing H3.V A particular feature of `the construction‘of lthis (i5 saidv ports,„said„air chamber having the. form of a lsolid ,ofrevolution with plane end surfaces device is to be seeninthe'fact thatithe `Contact and a height -equal to an uneven multiple of between the free ends` of the centrifugal governor lever arms |00 and |09 and the` switch lever ||| one-fourth of the wave length yoffsaid definite is constructed asra ball bearing. Upon the free ) frequency. ends of the bell crank levers |08 vand |09 sits a 3;.In a.siren.for producinga sound of pre half ball | I1, which can >be Vmoved laterally with determined wave length, wall means forming an in narrow limits in slots in thellever arms |08 axially` extending annular chamber having an and |09. The counter bearing of the vhalfïball outlet at one-endthereof, vibration _producing | |'| is-constructed as la ball bearing || 8, which 75 means Aincluding a circular row -of ports surround 2,407,175 10 ing said outlet and being positioned a ñxed dis tance from the opposite end of said annular chamber which distance is equal to an uneven multiple of one-fourth of the Wave length of the emitted sound waves, said chamber having as its inner peripheral wall a surface of revolution, said Wall means having as part thereof a recip rocating diiîerential valve axially movable to open and close said outlet, and means to supply to said chamber a compressed gas of controlled temperature. PETER ORLICH. GÜNTHER NEGEL. HANS HARTZ.