US1648226A - Sound-reproducing instrument - Google Patents

Description

Nov. 8, 1927. 1 648326 A. w. HARRIS SOUND REPRODUCING INSTRUMENT Filed June 23, 19.26 2 SheeES- Sheet, l

Nova 8, 1921. 1,648,226

A. W. HARRIS SQUND REPRODUCING INSTRUMENT Filed June 23, 1926 2 Sheets-Sheet 2 Patented Nov. 8, 1927.

- UNITED STATES PATENT oFF cs.

ARTHUR WILLIAM HARRIS, OF NEW YORK, N. Y., ASSIGNOR TO THE AMPLION' POM'IION OI AMERICA, OF NEW YORK, N. Y., A COBPORATION OF DELAWARE.

SOUND-REPBODUCIN G INSTRUMENT.

Application filed June 23, 1926. Serial No. 118,094.

novel construction of a sound reproducing instrument such as is now generally known as a speaker or a loud speaker.

In the development of the loud speakers adapted particularly for -use with wireless receiving sets, great difliculties have been met in unsuccessful attempts to construct a single instrument which will reproduce the low notes as well as the high notes. Experience has shown that a speaker-which satisfactorily reproduces the low frequency notes does not satisfactorily reproduce the high frequency notes and vice versa.

The present invention has to do with an improved loud speaker instrument which will satisfactorily and with exceeding efficiency reproduce low frequency notes as well as high fr uency notes. ThlS improved speaker also as in its favor a considerably wider range of eflicient and satisfactory re-' production than has heretofore been accomfore, to provide a novel construction of soundplished in loud speakers of this type.

The main object ofthis invention is,therewave reproducin mechanism whereby notes of both low an high frequencies will be satisfactorily and clearly reproduced.

Another object of this invention is to provide a novel speaker which has a particu larly wide range of note re roduction and which reproduces notes of high frequencies substantially as well as notes of low frequencies and vice versa. I

A further and detailed object of this invention is to provide a novel combination 40 of a relatiyely small vibrating diaphragm with a cone of modified form, in a loud speaker of the cone type whereby a very advantageous improvement with increased range of sound reproduction is obtained.

Another object ofthe invention is to supplement -a combined diaphragm and cone speaker with a born to thereby add to the total efficiency of the improved speaker.

A still further object of the invention is to provide a novel type of loud speaker which is exceptionally simple in its construcf'tion and operation and has vibrating elemanta of desirably light weight, rendering it moresensitive and permitting its manu facture at a relatively low cost.

Other objects and-advantages of the invention will be appreciated as the detailed description below is read.

The preferred embodiment of this invention is illustrated in the accompanying drawings wherein:

Fig. 1. is'a'n elevational view, partly in section, .0f the improved speaker showing a modified form of cone vibrating member af fixed to a diaphragm;

Fig. '2 is an illustration similar to Fig. 1 and includes a showing of a guard for the protection of the cone;

Fig. 3 is also an elevational view based on the "construction shown in Fig. 1 and illustrates in addition thereto, the use of a horn .which assists in the amplification of the sound waves and also cone;

Fig. 4 is a top plan view of a means for vibrating the diaphragm and cone member; Fig. 5 is a sectional view of Fig. 4 taken on the line 5-5 thereof;

Fig. 6 is a sectional view of the operating mechanism shown in Fig. 4 taken on the line .acts to protect the 66 of Fig. 5'; and

Fig. 7 is a erspective view of an element employed in t e mechanism shown in Fig. 4.

In producing this novel type'of simple loud speaker, there is preferably combined two vibrating elements 1n such a satisfactory manner as to obtain a very efiicient reproduction of sound waves over an exceptionally wide range. In carrying out the'most preferred method of combining these elements, there is provided a vibrating art which is particularly adapted to the e cient repro duction of notes of high frequencies, and there is also provided a, second vibrating part which most efliciently reproduces notes oflow frequencies. These parts have been brought into association with one another so that, in their normal operation, they vibrate in unison and efl'ect-a very pleasing reproduction of speech and musical notes over a wide range.

' In combining these two vibrating parts or elements, there results asound reproducing mechanism which may appropriatel be termed a compound vibrator. It will be understood that the two elements maybe combined in anydesired manner to accomplish the desired improved result as herein required to be obtained. It is believed, however that one of the reasons for obtainin the highly satisfactory results accomplishe according to this invention, resides'in the fact that one of these vibrating elements is attached to the other vibratin element at some place or portion thereo which normally vibrates during the operation of the speaker. Whether or not this is the explanation or main reason for obtaining such advantageous results, the improved speaker mechanism accordin to the invention herein illustrated and produce most satisfactory results in' operation.

In describing the preferred embodiment of the invention in a particular apparatus, or instrument, reference is made especially to Fig. 1 wherein a suitable base-holder 1 is illustrated as having one .of the vibrating elements in the form of a diaphr 2 mounted therein. This disk diaphragm 2 is preferably of metallic construction and is fixedly or semi-fixedly mounted in the baseholder. It is preferred that thisdiaphragm 2 shall be annular and shall be either permanently and firmly mounted between a hp 3 of the base-holder 1 and a cover edge 4, or between suitable rubber or resilient. sprlng gaskets. Thus, the diaphragm 2 is fixedly mounted in the base-holder in a predeter mined manner. It is also to be undertsood that-this diaphra may be aflixed or permanently mounte to the base-holder 1 in any other suitable manner.

To the diaphragm 2 there is added a second vibrating element or diaphragm-5, preferably in the form of a cone, and it is preferred to have this cone of materially greater size than that of diaphragm 2. This cone 5 in addition'to constituting a vibrating member, also may function as a horn for amplifying the sound waves 'whichare set up within the confines of the element 5 by the vibrations of that part or portion of the diaphragm 2 confined within. or lying adjacent. to' the smaller edge of the cone.-

The conevibrating element or part'may be made of any suitable material which is adapted to reproduce sound waves when this material is vibrated. In this instance, it is advantageous to make the cone'5 of a, suitable paper construction which may be impre nated or not as desired. The thickness of t e paper'or the amount of impregnation of the paper selected for the purpose of giving a required stifl'ness may of course be varied in order to obtain the desired sound wave reproduction.

The cone 5 may be held in association with the diaphragm 2 in any desired manner in order to obtain the most efiicient results. It

. has been found that the cone may be suitably smallest'diameter of the cone and eseribed has proven to;

and fir-mly held in association with the diaphragm 2 by forming 'a flange 6 at the asting or otherwise causing the flangeto ad ere to the diaphragm 2.

In considering the compound vibrator as a single or unitary element the cone part thereof may be considered as an extension from the diaphragm part.

The most satisfactory sound reproduction results of this compound vibrator have been found .When the cone 5 is aflixed to a portion of the diaphragm 2 which is free'to vibrate. Thus, it will be understood that the cone 5 shouldinot be attachedito the parts which" bind and support .the diaphragm 2, but should be mounted on some part of the diaphragm that is free-to vibrate. In the annulartype of diaphragm 2, the cone 5 will produce superior results when mounted on some portion of the vibrating diameter of the diaphragm or area. It is desirable in order to obtain some of the most satisfactory reproduction results, to have that area of the diaphragm 2 whichis confined within the cone 5, less than three-quarters of the total vibrating area of the diaphragm 2. It has been found that the most satisfactoryreproduction is obtained when the cone 5 includes substantially twothirds of the total area .of the vibrating part of the diaphragm.

It is well known that vibrating members such as thediaphragm 2,. when mounted as herein illustrated, are exceptionally good reproducers of notes of high frequencies.

It is also known that the cone loud speakers are exceptionally good reproducers of notes there is indicated a horn 7 which preferably is supported on cover 4 and which acts as a guard for the cone vibrating element 5.-

This horn 7 also provides a means for emphfying the sound waves set .in vibration y both the diahragm 2 and the cone 5. It will be underjtood that the vibration of the diaphragm-2-sets the air around it into vibration, and some of this air is pocketed within the confines of the cone 5 while the rest of the vibrating air will be within the confines of the horn? and will be amplified thereby. This horn7 also assists in the amplification of the sound waves set into vibration by the cone 5.

type of Any-suitable means maybe employed to satisfactorily set the com ound vibrator mto operation. The particu ar form of means which is herein preferred is specifically illustrated in Figs. 4 to 7 inclusive. It is preferred to employ two electro-magnets 8 and 9 in combination with a permanent magnet 10. The electro-mag'nets-a're so mounted that their pole pieces 11 and 12 are positioned relativelynear to'the diaphragm 2. Suitable electrical terminals 14 and 15 are shown for connecting the,electro-magnets to a current producing element. It is preferred to have the pole pieces 11 and'12 of L shape so that they may extend down through the windings of the electro-magnets 8 and 9 and be fastened to the extremities of the permanent magnet 10, which in this instance is preferably made up of three laminated plates of semi-circular form.

In most instances it is desirable to adjust the amount of air gap between the diaphragm 2 and thepole pieces 11 and 12 of the magnets for the purposes of locatmg the most sensitive position for the unit to work in, and it is usually desirable to have the pole pieces as near to the diaphragm as possible without having the diaphragm touch them when vibrating-at its greatest amplitude. In many cases it may be desirable to vary theintensity of operation of the loud speakers, and any suitable means may be provided for accomplishing this result. One form of adjustment which has been found satisfactory in the present apparatus consists in a means for moving the pole pieces 11 and 12 to and from the diaphragm 2. This is accomplished by mounting the permanent magnet 10 and the electro-magnets 8 and 9 on a stem 16 which passes throughthe baseholder 1 and is provided with a suitable nut 17 which' may be rotated in one direction or the other to vary the position of the magnets in respect to the diaphragmfQ. The construction preferably includes one or more springs 1Swhich tend to force the ole pieces toward the diaphragm 2. .A suita le type of spring is specifically illustrated in Fig. 7 and it will be noted that 6there are. two of these springs placed in opposition to one another. If desiredfa single spring 18 may be employed and the center thereof may engage the. bottom of the base-holder and'its free ends engage thesemi-circle permanent magnet as may be readily appreciated by reference to Fig. 6. In Figs. 5 and 6, the

cover 4 is shown as constructed to receive T1118 15 so' the base of a suitable horn. illustrated merely to show the adaptability ofthe operating apparatus, for in Figs. 1

- to 3- this cover 4 ha's'been shown cut away to provide for the mounting of a relatively large diameter cone vibrator element and to receive a suitable cone protecting member orahorn 7.

phragm has been described above in eneral terms, it may be stated that it may e substantially firmly mounted or fixedly mounted by inserting fibre gaskets at theedges of the diaphragm and between the lip 3 and the cover 4. The diaphragm may be semi-floatingly mounted by using rubber gaskets in place of the fibre gaskets. If desired, the diaphragm may also be floatin ly mounted by using annular gaskets, .pre erably of a metal, and providing large wave corrugations in these gaskets, thus making them of spring formation. I

It will be noted that the invention in'its simplest form is an improved loud speaker embodying anovel combination of two vibrating elements which are most efiicient regpectively for the reproduction of notes of di erent frequencies. The combination of these two vibrating elements isshown to be accomplished in an improved manner to give a most satisfactory, complete and advantageous tone reproduction. It "will be noted that one of the vibrating elements is substantially permanently fixed and that the illustrated means for setting the compound vibrator in operation, acts directly upon only one of said elements, i. e. the permalow frequency impulses. It will further be understood that. the two vibrating elements will vibrate in unison or as an integral structure duringnormal operation, the vi brations of the cone element or part of the compound sound reproducing member being dependent upon the vibrations imparted to the disk element or .part thereof, the two elements therefore being in effect, relatively dependent one upon the other in operation. While it has been herein shown that the means for setting the compound vibrator in operation acts directly upon the diaphragm 2 which is permanently mounted, it will be understood that said means ma operate upon any part'of the compound v1- brator constructedwith the cone part thereof firmly affixed to some portion of thediaphr'agm which is free to vibrate.

From the foregoing. detailedjtlescription of the preferred embodiment of the invention. the operation of my improved sound reproducing .device will be readily under into operation, so as to-impart-a vibratory movement thereto for the reproduction of sounds or notes transmitted therethrough, the disk diaphragm will obviously be caused to vibrate to different extents under low as well i as high frequency impulses, its fixed position relatively to the pole-pieces of the illustrated energizing means or unit preventing the same from being flexed sufficiently to be drawn into contact with said pole-pieces, yet permitting the same freely to vlbrate under the impulses received through said unit. When operated under high frequency impulses imparted thereto through the energizing unit, the disk'diaphragm will vibrate under the normal conditions of an ordinary disk diaphragm, with a the cone which is secured thereto vibrating as an integral and unimpeding or unresisting part thereof but acting as a born for the vibrating -port1on of said disk diaphragm, thereby amplifying the sounds emitted therethrougli.;--. When v operated under-low frequency impulses imparted thereto through the energizing unit,

'the disk diaphragm which is of a higher periodicity than the cone diaphragm will be caused to vibrate sufficiently to impart vibrations therethrough to said cone of lower periodicity so that thelatter will be more violently vibrated and reproduce the sounds transmitted at the lowerfrequencies, the

horn surrounding said cone serving to am-' plify the sound or sounds reproduced thereby. It will be noted that the cone diaphragm is entirely supported on the disk diaphragm and has no connection with the born or other element at its outer end and it will therefore be apparent that the cone and disk diaphragms comprising the compound vibrating element are dependent one upon the other in operation, since vibrations can be imparted to the cone diaphragm only through the disk diaphragm while said cone oifers'no resistance to the natural vibrations of the disk diaphragm which is effectively responsive to the higher frequency impulses to which the cone diaphragm will not respond. Thus my improved sound reproducing device with compound vibratoris adapted .to effectually and clearly reproduce sounds and notes within a much wider range of frequency impulses than that to which the ordinary disk and cone diaphragms will individually respond, the one element of the.

compound vibrator being adapted to effectual reproduction of sound where the other been herein described in detail a particular embodiment of the inventlon for purposes of full disclosures, and some detailed fea- I tures which are specifically claimed for a special advantage, many changes and modifications may be made in the particular con: struction and arrangement of parts without departing from .the broad scope of the invention which is outlined in the appended' claims.

I claim 1. In a sound reproducing mechanism, the

combination of a compound vibrator having that portion thereof which reproduces notes of high frequencies fixedly mounted and combination of a compound vibrator having a part thereof fixedly mounted and adapte to reproduce notes of high frequencies and to the vibrating part of the first art, said second part beingadapted to repro uce notes of low frequencies, and means for operating the compound vibrator.

3. In a sound reproducing mechanism, the

combination of a compound vibrator having fixedly mounted the part thereof which reproduces notes of high frequencies and havlng a second part attached to the vihaving a second part thereof firmly attached brating portion of the first part,'said second part being adapted to reproduce notes of low frequencies, and means for operating said compound vibrator.

4. In a sound reproducing-instrument, the combination of a part adapted to reproduce notes of high frequencies, said part being mounted in a fixed support and being constructed of metal, a second vibrating part attached to a vibrating portion of said first part and being constructed of material other than that of said first part, and means for vibrating said parts in unison. v

5. In a sound reproducing instrument,t,he combination of a vibrating part mounted on a fixed support, a second vibrating part mounted on a vibrating portion of said first part, said second part being constructed of a material of lighter-weight than the first part and being of greater size than the first part, and means for setting said parts into vibration to produce sound waves.

6. In a sound reproducing instrument, the combination of a compound vibrator having a high frequency vibrating part thereof mounted in a fixed support and having a low frequency vibrating part thereof afiixed to a vibrating portion of said first named part and being entirely supported by said first part, and means for operating said compound vibrator for reproducing sound waves.

7.. In a sound reproducing mechanism, the combination of a vibrating part for the reproduction of notes of high frequencies, a second vibrating part for the reproduction of notes of low frequencies, said parts being joined together so that only a portion of the vibrations of one of the parts will be transmitted to the other vibrating part, and means acting on one of the parts to vibrate both parts.

8. In a sound reproducing instrument, the. combination of a diaphragm adapted to reproduce notes of high frequencies, a cone shaped vibrating member mounted on a vibrating portion of said diaphragm, and

means for setting said diaphragm and said cone member into vibration.

9. In a sound reproducing instrument, the.

combination of a diaphragm vibrating memher, a cone vibrating member, saidmemhers being connected together and adapted to reproduce sound Waves, and means mechanically unconnected with either of said members for vibrating the same in unison.

10. Ina sound reproducing instrument, a vibrating sound reproducing element consisting of a relatively flat part mounted in a fixed support and an extension therefrom in the form of a cone brought into sound'reproducing vibration by the vibrations of said relatively flat part.

11. In a. sound reproducing instrument, the combination of a diaphragm adapted to be vibrated, a second and cone-shaped diaphragm having its small end aflixed uponca limited area of the first diaphragm so that a limited portion of the air set into vibration by the first diaphragm Will be confined Within the cone diaphragm, and means forattached to said diap ragm, the diameter of said cone member at the point of attach ment to said diaphragm being substantially equal to'two-thirds the diameter of thev1- brating portion of said diaphragm.

14. In a sound reproducing. instrument, the combination of a metal diaphragm-having its edge clamped .to' 'permanently mount the same in said' instrument, a cone-shaped 'pape'r vibrating member pasted to a vibrating portion of said 'diaphragm,the part of said conemember in engagement with said diaphragm adapted to enclose about twothirds of the vibrating area of said diaphragm.

15. In a sound reproducing instrument, the combination of a disk diaphragm adapted to be vibrated, a cone vibrating member afiixed to a vibrating portion of said disk diaphragm, a horn adapted to surround and protect said cone and also'aeting to'amplify some of the Vibrations from said disk diaphragm, and means for vibrating said diaphragm and said cone in unison.

16. In a sound reproducing instrument,

the combination of a disk diaphragm adapted to be vibrated, a cone vibrating member supported on a vibrating portion of said disk diaphragm, a horn adapted to surround and protect said cone and also acting to amplify some of the vibrations from said disk diaphragm, means for vibrating said disk diaphragm and said cone in unison, and means for adjusting the vibrating means to vary the amplitude of vibration of said diaphragm and said cone member.

17. In a sound reproducin instrument,

the combination ofa disk diap ragm adapted to be vibrated, a second and cone-shaped diaphragm aflixed upon a limited area of the disk diaphragm-so that only a portion of the air set into vibration by said disk diaphragm will be confined within the cone diaphragm, means for vibrating said diaphragms in unison, and a horn surrounding said cone-shaped diaphragm and adapted to amplify some of the vibrations of said disk diaphragm.

18. In a loud speaker, the combination of a base-holder, an annular metal diaphragm having its edge permanently held in said base-holder, a cone-shaped member of aper material having a turned-in flange at its'smallest diameter and adapted to have saidflange" pasted to said diaphragm, the

smallest diameterv of said cone being substantially two-thirds of the vibrating diameter of said diaphragm, a horn mounted on said -base-holder and extending therefrom to protect said cone-and acting also to amplify some of the vibrations of said diaphragm, a magnet fonvibrating said diaphragmand sald cone member, and adjustmg means responsive to spring pressures for moving said magnetrelatively to said diaphragm to thereby va of vibration of said -diap ragm and said cone.

19. In .a sound reproducing mechanism, the combination of a compound vibrator having a part thereof adapted to reproduce notes of high frequencies and havin a second part thereof supported on a vi rating portion of the first named vibrating part,-

the amplitude I said second named part being adapted to reproduce notes of low frequencies, and means for operating the compound vibrator.

20. In a sound reproducer, a compounddiaphragm being supported on the first mentioned diaphragm and so related thereto as to provide an. amplifyin means therefor, together with means or setting the compound vibrator into operation.

21. In a. sound reproducer, a diaphragm having a high natural period, a diaphragm having a low natural period, said last mentioned diaphragm being supported-on the first mentioned diaphragm and vibrated therewith, and means acting directly on one of said diaphragms for setting the same in operation.

22. In a sound reproducer, a compound vibrator, element comprising a disk dia phragm having a high natural period and a cone-shaped diaphragm having a low natural period supported thereon and providing an amplifying means forthe former, together with means for setting the compound vibrator in operation.

23. In a sound reproducer, a diaphragm having a high natural period, a diaphragm having a low natural lperiod and entirely supported on" said first mentioned diaphragm, and means for operatively vibrating said diaphragms.

In testimony whereof I afiix my signature.

ARTHUR WILLIAM HARRIS.

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