US1111463A - Horn and similar instrument. - Google Patents

Description

Patented Sept. 22, 1914.

3 SHEETSSHEET 1.

M. R. HUTGHISON. HORN AND SIMILAR INSTRUMENT. APPLICATION 11mm SEPT.1'5, 1905.

Patented Sept. 22, 1914.

a SHEETSSHEET 2.

Jwucul'oz fll'loz ucu' M. R. HUTOHISON. HORN AND SIMILAR INSTRUMENT.

APPLICATION FILED SEPT.15, 1905.

w Ms M m P $5 fihimmq @ad f I E STATES rArrENT-o EioE,

MILLER REESE HUTCHISON, 0F BEo EXvI LE, NEWjYoRK, AssIeNoaTo, LovE L- MQCONNELL MANUFACTURING COMPANY, oomonarrolv OE'DELAWARE, I 3' I norm AND SIMILAR aNsTRiIMENT.

To all whom it may concern Be it known that I, MILLER- REESE Horoii-nsorr, a citizen of the United States, and resident of Bronxville, in the county of lYestchester and State of New York, have invented certain new and useful Improve Y resonating or amplifying device, preferably of the Wind instrument type, means for exciting acoustic vibrations thereof, a motor for operating said means and a system for controlling the same. At the present time,

the air columns of resonators or horns forv the purposes referred to are excited by a blast made pulsating or intermittent, usually by a vibrating valve member, such as a reed oi; the lips of the player, the frequency -or note being controlled and determined by the resonant reaction of the air column of the instrument upon the reed or other vibrating member. These reeds .must be delicate, in order to perform their function and where expiosetltodirt and rough usages, as in the 1"Icase"ofl'autoinobile horns, are frequently found out ofiorder and in' need of renewal or repair atthe very instant-when they are most needed. fFrom the nature of things, thereed must open for the passage of considerable quantlties' of-air and will always-open in response to the least back pressure, as, for instance, by suction of the blast-producing device when refilling, orv

by high air pressure on the mouth of the horn, d'ue to high speed, a high head wind or both. In high speed operation of the auto'; a comparatively high but varying pressure usually prevails within the horn. Thus pz u-ticles of dirt, gravel; etc, are carried to thereed and cause it to fail to properly seat itselfcthereby causing it to fail to act as a valve and rendering it ino1'Jerative.' Moreoxer the meansfor supplying the air blast, whether by a connection to the exhaust of the engineer by thee inore-usual hand oper- Specification of Letters went. 7 Patented Sept. 1914.

I Application filed September 151, 1905. Serial No. 278,562.

ated rubber bulb and flexible tube, $re cumbersome, noteasily installed or operated and Tespecially'in'thfe case of therubberbulb and tube, expensive and requiring frequent renewal. a

I have devised my present invention with the object, among others,'of"providing a: means for exciting the air column 'of the' amplifier or resonator which does not require an air blast for its operation, is not liable to clogging by dirtfor injury by jar-1 ring, Which is, or may be independent of said air column, has no parts that are likely to Wear out or deteriorate in the course 'of regular use, which is capable of modification of note to'suit the taste or caprice ofthe operator and which maybe controlled w1thbut muscular exertion from any point, 'or

independently from as many difl'erentpoints as may be desired; As an alarm horn for high speed automobiles, the latter feature ;is of great practical importance;. for, in practice, it is frequently the casethat'a pas:

senger, who sees the dangers in the way, but."-

isisting or advising the driVer 'Tnay; get a needed relief from nervous tension, without in any ivay interfering with or discommod ing the driver, by simply soundingthe hornn In the practice of my inventiomgthe horn or amplifier; may be of any known;or desired construction. It is a means for determining or forming a column of air andpreferably has pronounced natural fundamental and who can'do nothingin the direction of asharmonicnotes. The movable member employed as an exciter is preferably an imperforate diaphragm j closed against all air drafts whereby air through the horn is prevented, and which cannot well be injured ,or put out f'ope'ration by dirt, gravel or rough usage. The motor for this diaphragm' may beany desired form of electromagnetic ,or mechanical all backward moveinentof' actuating means, suitably arranged for forc- Y ing it to pulsate at the desired frequency.

The preferred motor or actuating means, is l an clectromagnet using a power current adapted to cause a Wide amplitude bodily.

vibration of the diaphragm as a whole. This a v I electromagnet may be excitedfrom any sultable. source of current yielding a sufficient volume of said current, and thefluctuations of the latter may be controlled in many different ways; as, for instance, by an automatic circuitbreaking device such asis used to make and break current through the primary of an induction coil.

As a simple automobile horn, it is desirable that current fluctuations, or impulses of the vibrator, be of a definite frequency, corresponding toone of the notes or natural periodicities of/the horn. Where a vibratmg circuit closer or buzzer is used, the d'esired frequency or note may be attained by adjusting the natural vibratory period of the latter, or by changingthe elasticity, the weight or the effective length or the am li- 5' tude of oscillation of the vlbra'ting mem er.

In practice the former ferred'one.-. I

Where desired, a plurality of exciters of different periodicities, corresponding to the chords of an octave beginning with the natural fundamental note of the horn, may be employed. The various frequencies may be caused to excite the main air column, either through separate branch tubes and diaphragms, or a plurality of circuit closers may be arranged in parallel and operated by separate circuits. A With either of these arrangements, a set of four circuit closers, to be operated by .the fingers of one hand,

method is the pre so will be suflicient to controlthe production of any of the ordinary bugle calls. By merely vmultiplying parts and periodicities, so as to represent any desired number of notes, a

keyboard, as complete and of as great range as desired, may behad. The-notes produced are of greater volume and enetration than those of the ordinary air last, reed-operated'automobile horn and, by the before de-- scribed arrangements, musical com ositions 40 may be rendered, comparing in t ese 'respects with the effects of a steam calliope. Referring now to the drawings:

I Figure '1 is a diagram of a complete con- :"trolling system, an automobile being indicated in dotted lines to show the locations which may be selected for the circuit closers.

Fig. 2 shows an automobile horn and vibrating'attachment in side elevation. Fig. 3 is a vertical section through the case .of thevibrator and essential parts of the mechanism. Fig. 4 is an end elevation of the vibrator, with the rear,cover of the/case removed. Fig. 5\is a detail of the 3-point contap-t diaphragm buckling spring. Fig. 6 is a diagram, showing four vibrators operating.

' asingle vibrating diaphragm. Fig. 7 illustrates an arrangement of 4 harmonic vibrators, applied to a single horn. Figs. 8,

' 9 and 10 are views corresponding to Figs. 2, 0 3, and 4 respectively-but illustrating a modified' arrangement. I I

In the drawings, the horn or resonator l,

for determining thehoscillatory column of air, is shown mounted in the conventional 6 manner in the usual location on the autoerecl by the leather of the upholstery,'.as inmobile, the latter being indicated the upon the small end of the latter and from it extend suitable circuit connections 3, 4;.- One of the wires or 'leads 3, has serially connected therein the battery 5, which may be one especially supplied for the purpose or which may be the storage battery commonly used for the igniter of an explosive motor and adapted to supply a comparatively heavy current. The wire 4;, for completing the circuit, extends parallel with 3. In practice, these wires may be the ordinary twisted insulated pair of lead and return w1re,'commonly used in wiringhouseaetc. Connected across this air of-wires, 'there may be as many normally open circuit closers as may be desired. For instance, there may be a circuit closer 6 upon the steering wheel, as shown and others, 7, 8, 9, 10,.Within convenient .reach of each passenger. They may bearranged out of sight and covdicated, at 10. 9o

The vibrator or ezicitcr is compactly ar-.

ranged in a durable dust tight case 2,'preff erably of light non-magnetic material, such as aluminum, and, provided with a screw threaded'opening on the front side, "opposite the centerof the diaphragm; the size of the opening. and pitch of the thread being preferably standard'and adaptedio fit directly on horns now commonly used on 111- tomobiles. It 'will readily be understood that the operation of installing the device, on an automobile having an ordinary horn, is ery simple. -It is only necessary to unscrew the usualreed and screw on the diaphragm casing 2. A pair of twisted wires may .then be led serially through a few battery cells, either storage or primary, and carried up thesteering wheel and secured to any simple form of circuit closer, which may be clamped or otherwise fastened on the shaft, hub, spoke or rim thereof, in any desired manner. Such circuitcloser may be of the type normally spring-pressed open and adapted to be positively closed, or it may be arranged to stay normally open or normally closed, as set. by the operator.

Anyone of the switches may be placed 'in series with a loud speaking telephone transmitter as, for instance, the transmitter 12,- mounted on any sultable support 11,

mushioned in any desired manner and scrially connected with the switch 8, so that upon closing the latter the fluctuations of the transmitter are impressed upon the power current running the vibrator. Such a transmitter may be located in any desired position and may be arranged in operative relation to the reproducer of a phonograph When 'the transmitter is to be used instead of the vibrating circuit closer within the 13 case, the latter will be screwed up or other- 65 be changed greatly by adjusting this screw 45, whereas finer adjustments of frequelicy wise short circuited bythe operator, in a 'etc., may be made by adjusting the contact manner hereinafter explained. Other pairs screw-39. of wires and other controllers may be con- The screw 39 may be either locked by the nected in parallel, after the manner of 7 'screw 42, as described, or it may be left un- 70 8, 9, 10. i locked and free to be operated by a flexible The vibrator and horn may be assembled shaft 47, leading to any desired point in the as shown in Fig 2 and sold as a unit, or each automobile and terminating in the handle may be sold separately. Also, the horn and 48. For pleasure parties the latter arrange- 6 vibrator may,'if desired, be assembled in. a .ment is interesting and amusing, it being 75 single structure as, for instance, the case, possible to get a wide range of-notes by thus or any desired part thereof may be made an adjusting the screw 39, while in motion), It integral part of the horn. is quite practicable to playv simple tunes in The inner wall of the front cap 14 -is"pref-' this way. This flexible shaft: adjustment 15 erably plane faced and backof the same; may also be used to permanently close the 80 substantially-parallel therewith and. spaced circuit of the vibrator, when it is desired away a short distance, is the diaphragm that some other fluctuation determining 22;. On the back side of said diaphragm may member, such as -theloud speaking telebe a 3-point contact buckling spring 23, and phonecactuated by the voice of the operator behind this adjustably mounted a resonator other occupant of the car, or the phono- 35 ing wall or partition 24, carried by acylingraph, be substituted for the regular in-, drica'l flange 25,-exteriorly screw threaded terruptions of the buzzer. When the flextolfit the interior of'thewcylinder 13. In asible shaft is not used, the main function sembling this part of the device, the resonaand the adjustment of the screw is, to de- 25 tor wall 24 may be screwed in place, a paper te'rmine and adjust the frequency of the Vi- 9o washer 26 fitting over the end of the cylinder brator which may .be that of a natural note .13, the annular 3-point buckling spring, the of the born, with which it is used. The paper washer 27, the diaphragm 22 and the latter is the more normal and businesslike paper washer 28 being then placed in posiuse of the device and when the properad- 30 tion successively and the cap 14 forced therejustment for such purpose is achieved, the

over and securedby the screws 19'. parts are preferably locked in position. To The motor, or diaphgram vibrating dee-fiect the adjustment of my vibrator direct vice, comprises the longitudinally subto any horn, as that shown at'l, I first divided or laminated iron core 29, adapted secure it to the small end of the horn, then 3-5 .to project through the opening 30, in the connect the lead and return wires to the'loo resonator partition 24, and surrounding said post 49, 50, binding them between nuts 51, core is the coil orwin'ding 31,- held between 52, which are properly insulated from the non-conducting,preferably hard rubber, end case by bushings 53, 54. The wires are then pieces 32, 33.. 32 is mounted upon a transrun serially through the batteryand to one so verse segmental 'screwthreaded bridge 34. or more circuit controllers. The bridge Carried by this bridge is the vibrating cirpiece 34 is then screwed inwardly, until the c uit closing and circuit breaking device, for core is quite close to the diaphragm 22. interrupting the current and-causing pul- The vibrator is then set in operation, and v sations in the'coil of the electromagnet. It the screw 39 turned in and out until the 45 comprises a compound vibrating member, desired note is obtained. In practice, it

I consisting of amain leafspring 35, carrying will always be found preferable to have an armature 36 of magnetic material, and a this note one harmonious with a natural secondary spring 37 carrying a sparking note of the horn. 'It is very easy to tell contact 38. The latter contact may be of when such a note is attained, by reason of 'e-U platinum, or platinum-iridium, and is the increased loudness of the sound; and

adapted to contact with and close the ciralso where the core is too close to the diacuit through a contact of similar material phragm, because the increased amplitude of 011 Screw 39 Ca y the standard 4Q, vibration of the latter causes it to strike the which, like the other parts mentioned, is secore. The adjustment of screw 39 may then 55 cured to the bridge piece 34 s, for instance, be fixed by the clamping screw 42. .and the by" screw 41. The free end of 40 is split to frequency of the vibrator thus maintained the screw. 39 and is provided witha transat the desired note. The bridge piece 34 verse pinching screw 42, for locking 39 in may then be adjusted out, until the diaposition. The vibrator ismounted upon phragm just clears it when vibrating most 60 an insulating block 43 by screw 44. A screw strongly. The space behind the diaphragm 45, tipped with or contacting with an insuis then adjusted to the space in front of it, lating block 46, serves to adjust the normal and to the selected frequency which may position of the free end of the yibrator when correspond to a natural note of the horn, by at rest. The frequency of the vibrator" may turning said partition 24 to the right as far as it .will go, by means of a spanner engagl ing notches- 56 Still keeping the horn in a basic frequency may be determinedby se- J operation, the partition 24 is adjusted outwardly, by screwing slowly to the left, until the sound becomes much louder. Whenthis is the case, the spaces in front and back of the diaphragm will be balanced for the maximum amplifying effect. "By' thus adjusting, first the vibrator and then the air space, to the frequency of the horn, remarkably amplified vibration of the air column of r the latter may be obtained.

I find that where the amplifying space or chamber on the back side of the-diaphragm is quite small as compared with the length of the horn, there is a marked synchronized amplifying effect when said space is properly adjusted'as above described. In referring to "this effect as a resonance effect, .to the partition 24 as a resonant walland to the space between such partition and the vibrator 22 as a resonant space, I do not intend thereby to exclude any reinforcing reaction in which vibration of the partition 24 may have a part, or any cushioning actlon WhlCh the confined air may have relative to the air column of the horn or to the air in the space betweenthe diaphragm 22 and thefront of the casing. I make any openings which could pass air, such as that at 30, as small as possible. I intend to cover all the possible operations of this part of the device in ef fecting amplification of vibration of the-diaphragm 22 regardless .of whether and to what extent such eifects be resonance efiects or pneumatic cushioning effects or sounding board eflectsl a The effect of buckling spr1ngs,'such as 23, is to give the effect of greater stiffness to the diaphragm and to determine the number and position of the nodal points of the vibrations thereof. The number of sectors 1s alwaysanf'eyen one and the efi'ect of a three point"oritact arrangement, such as shown, is "to" cause theifdiaphragm to vibrate in six sectors. The" number may be increased by changing the'numbef of suchcontact springs 1 ,so that there will be8-10-12 l4 16, etc.,

sectors, the ratio of frequency of vibration being as the squares of one-half the number of secto rs, as for instance the squares of 2 3- @567 and 8 resp 3 for the I u s-10 42 147-16, etc., sectors. Eran the above it will be evident that the hig'herii the frequency of movement desired for the diaphragm the greater will be the number of these contact springs 23. Where diaphragm itself being proportional toits tliickness and inversely; proportional to the square of its diameter, Wha't may be termed leeting a diaphragm of proper thickness and diameter and this basic frequency-may in'turn be modified in the manner above described. In so much asrthe hornand vibrator may be designed and constructed one for the other and sold as a unit, all adjustment may be made in the factory. 5

The note produced by my instrument is of great volume and carrying power and may be made of good musical quality. The penetratlng or carrying quality seems to be dependent on the sharpness of vibration of the diaphragm, whereas the finest musical qual Y ity requires somewhat less sharpness of movement, resulting in a note of apparently not much less volume but of somewhat less carrying power.

, Many of the details of the above described construction and arrangement of parts, .are

worked out with a View to obtaining the maximum volume of sound, whether sharp and penetrating, or rounded and musical,

while certain others of the details may be specialized to increase one or the other of these qualities.

The volume of sound is in all cases inr- -proved' by my. particular arrangement of verging cone, having a 'base'approximately;

the size of the diaphragm and an apex the discovered however, that the inner 'face of. r

the .case' should be substantially parallel with the diaphragm, that, the passage therefrom: should be of'about the diameter shown" and should be made straighter cylindrical.

The diameter of the small end of the horn is practically fixed, by'reason of its being ad ustable to existing horns, and if the passage converged from the horn to the diaphragm the opening to the diaphragm chamber would be t 0 small. Moreover. I-have found that the pening should cover a certain areaat the center of diaphragm, about as shown in the drawing.

- Other factors of volume of sound are the amplitude and the abruptness of the current fluctuation in the coil. In order that these may be great, the winding 31 should be of 1 low resistance and may be as low asl or 2 johms. The reluctance of the winding and its iron core shoill'd be small and to this end the core may-be formedof comparatively netic in'sulation.qThe make and break of it may not be disturbed by jarring of the vehicle, it should be formed Wltll com aratively stiff springs of substantial dimenio'o, size of the small end of the horn. I have I v sions. The volume of sound isalso greatly augmentedbymaking the frequencies of the movements of the diaphragm the same as the frequency of one of the natural notes of the horn, the column of air in the horn in such case vibrating in syntony with, and

. reacting on, the diaphragm, t us reinforcing; and amplifying the" force" movements Y i caused by the electromagnet 1 In order to get the best reinforcingand amplifying effect of the resonant air column.

thediaphragm frequency should'not be com plex,.but should be a single frequency-2 It point'contact buckling spring, so that. its natural. rate of vibration will be very high as compared with the intervals between the electrical-impulses.

The .low resistance winding of, compara tively low inductance and the sharp make and break fluctuations in the magnet, which are most suitable for volume and penetration, may-be. modifiedin favor of musical quality, by considerably increasing the inductan'ce of the winding, 01; using a separate tuning inductance in series therewith, which may be adjusted to the natural period f. the horn, so that therise of magnetism in the electromagnet operating the diaphragm, will be smoother and more gradual. In these ways fiuctuations can be smoothed on, so that the periodic movements of the dia-. phragm will be slower and, if necessary, to].- low approximately a sine law. This causes 'some sacrifice of penetrating quality of the sound, but only a minimum sacrifice of volume at short'ranges but it may be compensated for by resonant rise of current, where a condenser is used, or by utilizing a source of greater elec'tromotive force giving greater amplitude of current, resulting in greater' magnetization and f-greater amplitude'of movement of the diaphragm,

horns may be-combined to gi've any desired number of notes and severalnotes may begot from'asin'gle horn, either by attachingseveral complete vibratorcases thereto, or by'having several outside circuit clos e'rsacting in parallel with each other, in serieswith a single coil 31 and diaphragm 32.

In Fig. 6 I have shown the latter arrange- 'ment, the born 1 and case 2 being as usual,

but the circuit closer, corresponding to 37,-

either' short-circuitedor removed. There are lead and return wires 3, 4, serially connected to the battery 5 Bridged across these wires, in parallel with each other, are a. plurality of independent electro-magnetic x As before stated any desiredhnu'mber ofcircuit closers diagrammatically indicated at 60, 61, 62 and 63. These circuit closers are each 1n series with the winding 31, in the case 2,- and are controlled respectively by the keys 64, 65, 66 and 67, mounted upona single key-board 68, adapt- 1 circuit controllin ed to be located in'any desired position-as, for instance, in place of any of the circuit controllers indicated in Fig.1. Each of these vibrating circuitmak and break devices. is tuned in any oft-he ways hereinbefore indicated, preferably each to 'correspond to a different horn, 1. L 4

f As this arrangement approximates and, in effect, constitutes a kind of musical instrument, and especially since one or more of the notes-may be sounded at the same t1me,'1t

will sometimes be found desirable to soften and smooth the vibrations, to improve the' musical quality. This may be done by any of .the expedients" hereinbefore indicated.- The inductance of each. circuit breaking magnet may be increased, or an adjustable inductance may be placed in a part of the circuit common to all of the branches, or individual adjustable inductances maybe in- .serted ineach branch, or any of the expedients may fbe'employ'ed. For instance, the inductance 68 may be adjusted so as to smooth the fluctuations sufliciently 'to improve the quality of all the notes of the branch, to. perfect the' tuning more closely to the-particular frequencyof the fluctua'' tions'there'o-f. It is preferable and usually simpler to have -most of the effective inductance used for tuning, in a single wind ing.* For this reason-it will sometimes be found'desirable to put allof the inductance in themagne't winding, rather than to employ auxiliary inductance. The key-board 68 may also be used to operate the arrangelment shown in Fig. 7 consisting of a group of four independent diaphragms and vibrators attached to single horn 1 by. four branches/Z4 extending out from a common- 'couplin 16, adapted .to be screwed to the ,horn. hese branches are preferably at as natural frequency of the so; i

octave within the range of the key-board small an angle'aspossibleto the axis of the I horn soas to avoid reflection and interference of thQVlbIaUOIIIlII passing from the branches to the horn;

:Ihezconstruction of the-automobile horn" for purposes of amusement and recreat on and to give forth harmonious notes, pleasing to the ear, isof great importance; for the.

supply of certain of the demands of the trade,

and not at all inconsistent with itshse as a For high speed automor bil'es, however, particularly for use in high speed road races and touring, the horn be-.-

'comes a, factor in the safety both of the warning signal.

- automobile and its occupants and of the regular trafficpf the road, and the musicalv quality of its note should be made subservient to the alarm quality. I have hereinbefore described how the note. may be made loud and yet perfected in pleasing musical quality to any desired degree, but in practice this very quality I have discovered to be inherently objectionable, because in a. sweet note or harmony of notes, however loud, there is a certain pleasing eifect upon the ear andbrain of the bearer whiclrat tracts attention readily enough, but which does not excite that instantaneous alarm which is desirable. Safety .at high speed requires not only that the sound be loud and concentrated but that it be harsh, disagreeable and penetrating, so as to causein the mind of the hearer an instinctive, automatic,

reflex, physical impulse to get out of the way, without the necessity of any intermemakin diate mental process of reasoning. For these purposes, all the ex'pedients hereinbefore' specified, regarding low impedence of the coil, sharpness of the makeand break and stiff, snappy movement of the diaphragm, should be employed and I have devised certain additional features, contributing to further efficiency in this same direction.

The vibrating diaphragm may be almost entirely deprived of its pleasing quality by its natural period high, particularly by ma mg it stifi and snappy and also byuse-of the multiple contact spring hereinbefore described. Its note may be rendered yet more alarming by causing vibratory imdesired note.

pact thereon, at-a rate corresponding to the One way of accomplishing this, is by adjustin the core of the electromagnet, so that the diaphragm will just touch it at the extreme limit ofeaclr inward movement, and when this is done the pole piece of the core should be slightly rounded,

or shouldbe provided with a rounded projection, so as to provide a single firm tapping contact at one point, adapted to 'break up and multiply the move'mentsofthe dia-- cial modified form of tube and phragm, thereby making its note complex and harsh instead of simple, harmonic and musical. ll

In Figs. 8, 9 and 10, I have shown a speof vibrator case, adapted particularly for high, speed Work. In Fig. 8 the horn l is modified to more nearly approximate a tube, the sides being more nearly parallel and the flare at the end being entirely'omitted. 0n the end of this horn may be screwed; case 2, which maybe provided with, or may be secured by screws 61*. The mechanism within the case 2, is modifiedin particulars which may be obvious from Figs. '9 and 10. The case comprises screw a threaded cylinder 13, front closing cap 14: and rear closing cap 15*; a.

segmental screw threaded bridge piece 34*,

carrying electromagnet 31*, having a core '20, projecting through partition 24%; Front cap l4 secures in place metallic washer 62 multiple contact spring 63*, diaphragm 22 and washer Ge all very'much as in the form first described, the case and diaphragm 22 however, being preferably of greater diameter.

The circuit is made and broken by movements of the diaphragm, to and from a stationary contact maker 65 adjustably secured in the support 66, projecting through the wall 16 and insulated therefrom by the sleeve 67*. A platinum iridium contact piezice is rigidly secured to the diaphragm an same material is secured to the end of the member 65 The support 66 projects outside the case and is secured by locknuts 69 and 70 shown in dotted lines in Fig. 10. Outside of these is secured the circuit connection 71, by means'of a nut 72 which may also be provided with a locking nut, if desired. The partition 24*, is preferably formed with a forwardly set portion 24", setting upclose to, and parallel with, the diaphragm 22*. In this arrangement, the' circuit is normally closed from the battery connection 71 through the support 66 the ad- .justable rigid abutment 65, the diaphragm 22*, the case 13, bridgeS l, coil connection coil 31, connection 81, binding post 49 and lead 82. As soon as the operator closes a corresponding'contact piece of ,the'

the outside circuit at any of the points shown in Fig. 1, the magnet is energized by the current flowing as just described, the diaphragm 22 is drawn downward and the circuit is broken, deenergizing the magnet and permitting it to snap back intocontact with the rigid abutment 65 thus again closing the circuiti. This operation is repeated so long as the outside controller is closed, and every return movement of the diaphragm 22- causes a sharp, snappy impact upon the stationary. abutment 65". For the high speed purpose, it will usually be found desirable to design and construct the tube 1 and vibrator 2* for each' other and adjust them beforehand. We may select a tube'say 1} inch in diameter at'the small end, 2.7 inches at thelargeend and 19 inches long, sides being prefer ably alongthe straight lines of a cone asshown in Fig.8 but flaring only about half as much as shown in that figure which has been distorted by shortening about one-half from the dimensions above given. Such a horn will answer to a note approximately 3 feet long which is about 18w E, having a freouency of about 320 vibrations per second. Thediaph agm may be tuned to this frequency, but a higher one maybe found more penetrating and more alarming. ,We may the higher note.

4 duplication of the half waves of 60 self to any specific forms 5 ness and elasticity and by use of the multiple contact springs hereinbefore described, the diaphragm" may be tuned to 1920 vibrations. If the diaphragm selected has a natural free, vibratory period equal to the first mentioned 10 fundamental period of the tube it may be caused to sound any desired higher octave, by using diaphragm contact springs having the suitable number of contacts to form the desired number of sectors, which will ive Having turned the (iaphragm 22 in this way, the diaphragm 24 is then adjusted in the manner previously described in connection with Figs. 2, 3 and 4. Everything may then be locked in posi- 20 tion, as this form of the device is intended for maximum efl'iciency as an alarm, rather than for ready adjustment to suit the caprice of the operator. When thus arranged, the note will have all of the characteristics de- 5 sirable for maximum efliciency as an alarm and.fthe constants being once determined, construction and arrange ment is easy; The tube 1 has a plurality of complete sound within its length and for this reason and also becauseof the omission of-flare at the end, throws a great volume of sound, of penetrating quality, almost directly ahead. r I

The tuning of the vibrator frequency, or of the diaphragm frequency, with respect to the horn. maybe perfected in whole or in part by chang' g the effective length of the air column of the latter. This may be 'ac- I 40 complished in avariety of ways, as for "in- 1 stance, by clipping off or adding to the large end of the horn shown in Fig. 8, orby lengthening or shortening a section at the smaller end of either form of horn. Aconsiderable range of adjustment is also possible by screwing the vibrator case outwardly and inwardly at its point of screw-threaded coupling to the horn or, where desired, an intermediate adjustable telescopic section of horn'may be used. In fact change of the effective length of the air column of the horn may be accomplished by any known or desired expedition which is or may be. employed for adjusting musical horns of the conventional type.

While I have very fully and accurately described and shown my invention, it is nevertheless a broad one and I intend to claim all equivalents and I do not limit myor elements not specified in the claims ereof.

I claim as my invention:

1. In a device of the class described, :1 casing having a substantially plane front wall and a diaphragm substantially parallel therewith and spaced therefrom a distance slightly greater than that of-maximum amplitude of vibration of the horn, in combination with means for vibrating said diaphragm at a definite frequency and an adjus table wall forming with said case a resonant chamber adjusted to said definite frequency.

2. In a device of the class described, a substantially dust tight casing and a diaphragm secured therein, in combination with an electromagnet, interrupter and resonant wall behind the diaphragm, all separately and independently adjustable, for the purpose described.

3. An acoustic instrument, comprising a horn the same ata definite rate in combination with walls, forming approximately equal inclosed air'spaces or chambers, at the front and backthereof, the front stantially parallel with said the rear wall being to said diaphragm.

1. An acoustic instrument, comprising a horn diaphragm and means for vibrating the same at a definte rate in combination with walls forming air spaces or chambers at the front and back thereof, said spaces beingbalanced for maximum amplified vibration of the diaphragm when vibrating at said rate. r I

An acoustic instrument, comprising a horn diaphragm and means for vibrating the same. in combination with walls formdiaphragm and adjustable with respect ing air chambers or spaces at the front and back thereof, and means for adjusting said spaces to produce maximum amplification for vibrations of aselected definite rate.

6. An acoustic instrument. comprising a horn diaphragm and means for vibrating the same, in' combination with 'walls forming air spaces cr chambers at the front and back thereof. the rear wall being in a position of maximum amplification for vibrations of a selected definite rate.

7. An acoustic instrument, comprising a casing and, inclosed therein, a diaphragm, a vibratory interrupter and an electromagnet having a core in operative relation to both. in combination with a wall or partition behind said diaphragm adjustable independently thereof and forming with said casing a substantially closed air chamber at the back of said diaphragm.

8. An acoustic instrument, comprising a casing and, inclosed therein, a diaphragm, a vibratory interrupter and an electromagnet having a core in operative relationto both, and walls arranged to form air spaces wall being subat the frontand rear of the diaphragm. ad-

justed for maximum amplification for vibrations of a selected definite rate.

9. An acoustic instrument, comprising a i casing and, inclosed therein, a diaphragm,

avibratory interrupter and an electromagnet. having a core in operative relation to @both, in combination with walls forming air spaces or chambers at the front and back "ithereof. and means for adjusting said spaces Ito maximum resonance for vibrations of a selected definite rate.

10. An acoustic instrument, comprising casing and, incl0sed therein, a diaphragm, a vibratory interrupter and an electromagnet having a core in operative relation to both, and a partition or wall in the rear of said diaphragm, and means for adjusting it to a position of maximum resonance for vibrations of a' selected definite rate..- '11. A born or pipe anda casing. in com- 7 bination with and inclosing a movable member,]a vibrator of definite frequency and i an electromagnet in operative relation to 'each,together with means for adjusting thefrequency of the vibrator to a natural note or. acoustic frequency of a horn, and means for simultaneously adjusting said vibrator and the core of said magnet away from the mova ble member, to compensate for the increased amplitude of vibration of'the latter when the frequency is so adjusted.

112.,A. horn or pipe and acasing adapted itoi'be secured over the end of said horn or pipe and in combination with said cas- *ing and inclcsed. thereby, a diaphragm, a vibrator of definite frequency and an electromagnet having its core in operative relajtion to eaclntogether with means for adfjustin'g the frequency of the vibrator to natural note or acoustic frequency of a horn, and means for simultaneously adjusting said vibrator and coreaway from'the diaphragm, to compensate fonthe increased amplitude of vibration of the latter when "the frequency is so adjusted.

13. An attachment for hornscomprisinga dust tight case provided with an opening anda screw threaded tubular projection in combination with adiagram, an electromagnet and an adjustable vibrating circuit breaker within said case in operative relation to-each other and to said opening, said el'ectromagnet and circuit'b'reaker and adjusting means for the latter, being mounted from said diaphragm.

on a single support for adjustment to and "11; A signaling device, comprising an acoustic vibrator, electrically actuated means for vibrating the same, a plurality of frequency controlling means operative rev controlling means.

"lat ion to said vibrating means, and means for; independently. actuating each of said 15. A signaling device comprising a diaphragm capable'of vibrating at any one of a considerable range 4 of frequencies, vibra umn, in combination with an electrically energized motor for said diaphragm and a plurality of circuit controllers of definite'frequency in parallel with each other and in se ries with said motor and a source of electromotive force, together with independent controlling switches in each of said parallel branches. 1

17. A ham or similar means adapted to determine a resonant air column and a dia phragml-in operative relation to'said column,

combination with an electro-magnet for moving said diaphragm and a plurality of circuit controllers of definite adjustable frequency connected in parallel with each other and in series with said electro-magnet, together with means for controlling independently the operation of each of said circuit controllers.

18. -A horn or similar means adapted to determine a resonant air column and a diaphragm in operative relation to said column in combination with an electromagnet for 'moving said diaphragm and a plurality of automatic vibrating make and break devices connected in parallehwith each other and in series with said electromagnettogether with a switch in each of saidparallel circuits.

19. A horn adapted to transmit a'w ide range of frequencies'an'd to resonate more.

strongly to certain selected definite frequencies, a diaphragm for one'end'of said horn and anelectromagnet for actuating. said diaphragm, in combination'with means for energizing said magnet ata desireddefimte single frequency and other means independent thereof for energizing said magnet by complex fluctuations, said latter means consisting of a microphonic resistance and means for throwing said microphomc resistance in andout of circuit withsaid magnet energizing means.

20. A- horn adapted to transmit a wide. range of frequencies and to resonatemore strongly to certain selected definite frequencies, a diaphragmforone'end of said horn and an electromagnet for actuatingsald d1aphragm, in combination with means for energizing said magnet at a desired definite single frequency and other means independent thereof for energizing s'aid ma'g net by compleir fluctuations Sald' latter means comprising a microphone ofthe loud speaking transmitter type and switch control means for passing currents of considerable amperage serially through the latter and through said electromagnet.

21. In an acoustic instrument, the combination of a horn, a diaphragm, an apertured' front wall forming with said (lia-v phragm an annular air space or chamber at the front of the latter, a sound projector carried by said front wall, a back wall adjacent to said diaphragm and forming therewith an air compression space or-chamber 1n the rear thereof and havmg a comparatively small aperture therethrough, and electricall operated means positionedin' the L rear 0 said back wall and having a portion projecting through said aperture and sub-' stantially closing the latteriand operatively disposedin respect to said d ap ragm to force upon, the latter bodily movements or vibrations of high frequency and of sufiicient amplitude to generate a loud warning signal.

22. In an acoustic instrument, the combination of a horn, a diaphragm, an apertured front wall forming with said diaphragm an annular air space or chamber at the front of day of Sept. A. D1905.

MILLER REESE HUT CHISON.

Witnesses: 4 G. C. DEAN, 4

K. A. MORRIS.

New York and Stateof NewYork this 1st

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