US1696784A - Acoustic apparatus - Google Patents

Description

M. WElL ACOUSTIC APPARATUS Dec. 25, 1928. 7 1,696,784

Original Filed y 20. 1924 3 Sheets-Sheet 1 g ,1 g 44 34, 44 ZQ J Z? 14 l i A as INVENTOR' Marz'mz/z'an iI Pz/ fi vvz/M I M ATTORNEYS M. WEIL ACOUSTIC APPARATUS Original il y 20, 1924 s Sheets-Sheet 3 Dec. 25, 1928. A 1,696,784

ATTORNEYS Patented Dec. 25, 1928.

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MAXIMILIAN'WEIL, or NEW YORK, 1v. Y.

ACOUSTIC APPARATUS.

Application filed May 20, 1924, Serial No. 714,574. Renewed November 12, 1928.

My present invention relates to sound reproducers and more especially to amplifying sound reproducers, and has a preferred application to phonographs in which the usual horn or amplifier serves also. as the horn or amplifier of a radio or telephone receiver.

It is among the objects of the invention to provide a combined apparatus which can be used at will, either as a phonograph or as a radio loud speaker, without, however, 1nvolving any change or mutilation of the usual approved phonograph sound box, tone arm or amplifier, which avoids any extra drag or wear on the phonograph record even though a telephone receiver element much heavier than the usual sound box is employed, and in which the sound vibrations emanating from the receiver diaphragm are efiiciently amplified without loss by leakage, from near the throat of the amplifier.

Another object is to provide a construction of the type mentioned in which the volume of sound emitted from the amplifier horn in radio operation, can be delicately varied or adjusted at will, without manipulation of the electric control elements of the receiving set and without the loss in efficiency due to leak with respect to the phonograph tone arm. v

Another object is to provide atone modifier for a simple phonograph, or for one combined with radio appurtenances, which in all settings thereof will provide a continuous conduit for sound without sharp valve elements projecting across the sound passage that might impair the effectiveness of the production.

Another object is to provide a construction of the type mentioned devoid of arrangements or elements that might develop looseness or rattle, which may be incurred, for instance, in constructions embodying flap control valves or involving the substitution of a radio receiver for the sound box in changing from phonograph to radio operation and vice versa.

Another object is to provide a unit or assembly simple, rugged and compact, which willenhance the attractiveness of the phonograph and which can be easily applied, without the exercise of skill to phonographs of the type now in use, in order to accomplish the various objects previously noted.

In the preferred embodiment ofthe invens tion, the sound vibrations whether from the phonograph sound box or from the telephone receiver or other telephonic speaker are admitted into the small end of the amplifying horn, so that the full length of the amplifying horn is included in the acoustic circuit for both phonographic and telephonic reproduction.

In a preferred embodiment, I provide a conduit which I call the radio conduit, preferably fixed with respect to the moto-rboard. mounting a telephone receiver element at its smaller end and flaring-to mergeflvith the sine. l end of the amplifier. Means is provided to prevent, during radio operation, any communication between the radio conduit and the conduit that connects the sound box with the small end of the amplifier. For this purpose, I provide a valve, which in one setting shuts on the tone arm with respect to the amplifier throat, while affording a direct communication from the telephone receiver to said throat, and in another position affords communication between the tone arm and the amplifier throat, while preferably closing oil the conduit leading from the radio receiver. A rotary valve is preferred and more especially one which has intermediate settings, so that it performs in addition to the functions noted, that of a tone modifier by which the volume 01 sound emitted from the horn can be regulated, either in phonograph or in radio operation, but preferably in both modes or" use.

The radio conduit is preferably embodied in a casting, the valve constituting an element in the connection from said conduit to the amplifier throat, said valve also controlling a passage oi more or lossuniform crosssection, which I call the phonograph conduit, and which connects the mouth of the tone arm with the throat of the amplifier. In the preferred detailed construction, a unitary casting is provided which may be rectangular in external form, is secured to the motorboard and includes both the radio and the phonograph conduits, cast thereinto, the former preferably of rams-horn shape to provide conside able length in a small length of casting, the latter relatively straight. lhe two conduits extend preferably either diametrically opposite, or at some other angle relative to each other, and provide a valve casing at their junction in which is disposed the rotary control valve, the latter operable by an exposed knob.

In the accompanying drawings,

F igL 1 is a. fragmentary top plan view of a phonograph embodying my invention,

Fig. 2 is an enlarged view. in transverse section taken along the line 22 of Fig. 1,

Fig. 3 is a view in longitudinal section taken along the line 33 of Fig. 2.

Fig. 4 is a fragmentary view illustrating the controlling valve moved to its other extremeposition,

Fig. 5 is a plan view of the handle and dial for the. controlling valve,

Fig. 6 is a sectional view taken along the line 6-6 of Fig. 1,

Fig. 7 is a view similar to Fig. 1 showing the selector unit above the motorboard, and

Fig. 8 is a sectional view of one of many possible modifications.

The phonograph 10 shown of conventional construction includes a motorboard 11, above which is the usual-turntable 12 (Fig. 1) that carries the disk record 13, and is rotated by motor. (not shown). In applying my invention to a machine of this general character, the motorboard isformed with a cutaway portion or opening 1 1 for the acconr mo-dation of a casting 15, formed with a peripheral flange 16 seating on the edges of the opening 1 1 and held in place by screws or similar securing devices 17, passed through lugs 18 at the ends of the flange. The exact shape of the casting is, of course, subject to considerable variation, but for purposes of convenience in assembly and attractiveness in appearance, I prefer to make the body of this casting of generally rectangular shape fitting Within a rectangular opening 14 int-he motorboa-rd. Aluminum is suitable for the casting, but various other materials may be substituted.

Thetl'iroat 19 of the usual amplifier or horn is provided with an external flange 20 (Fig. appro iiriately secured to the lower end of a control valve housing 91, integral with and disposed aymroximately centrally of the casting. Rotatably mounted in the housing 21 is a valve 22 operable to selectively place the amplifier 19 in communication with either of a pair of conduits or pa. sage- ways 23 and 24. in the casting at opposite sides of the valve. The passage-way 2 1 is relatively wide and may be of substantially the same cross-sectional area. throughout its length, although even along this short length, a slight taper is desirable, and when the valve is set accordingly, connects the amplifier 19 with the large end of the tone arm 25 of the phonograph. The tone arm, which may be ofenti'rely conventional construct-ion, carties the sound box Band is swiveled in a socket member 26 at the open end of the passage 2 l which thus forms a continuation of the sound wave channel in the tone arm. The tone arm 18 secured against accidental removal from the socket 2G by a stud 27 carried at the upper end of'a curved arm 28 communicates with the face of the casing 1 18 provides a mounting for a radio repro; ducer of any desired type, such for instance, as the telephone receiver 31. Preferably the receiver is formed with a depending socket member 32, encircling the projecting upper end of the bushing 30 andsecnredthereto by set screw 33. If it is desired to mount the telephone in concealed rather than in exposed position, it may be secured to a boss 3% integral with the casting and communic-at in g wi l h the neck of the passage-way (Fig. 6). This boss or nipple is ordinarilyclosed by a plug and the position of the plug 35 and bushing 30 may be reversed when it is desired to attach the telephone in. a concealed position within the motor casting.

As seen most clearly in Figs. 3 and 4, the rotary valve member is formed with an opening or cut-away part 36 adapted for registration with the respective passages 23, 2 1 and is formed with an external groove 37 receiving a set screw 38 projecting through the valve casing, engaging with the ends of the groove to act as a stop and limit the turning movement of the valve in each direction.

The conduit connecting the telephone receiver to the amplifier throat should diverge and preferably be relatively long, so that the wave front can gradually increase frpm the relatively small receiver opening to the much larger amplifier throat. On the other hand, the conduit 24 connecting the mouth of the standard tone arm to the throat of the amplitier, which elements are of about the same diameter, is preferably relatively short, since this conduit acts as a connector with little or no amplification. For neatuess of construction, it is preferred to provide the valve and knob near the center of the rectangularcasting and the telephone receiver and tone arm at equal distances therefrom toward the opposite sides thereof. Accordingly, to provide the long passage for the radio conduit, the latter is made of reversely curved, generally ramsdiorn shape, while the former is relatively straight.

In the extreme positions of the valve, it is desirable that the latter provide an effective opening as best shown in Figs. 3 and 1 with respect to the conduit of substantially the full'diameter of said conduit, yet in each This stud engages a fiat- IUU ofthese extreme positions, the effective conduit is to he completely closedjoff fromthe other conduit. If the two conduits have equal. diameters, which is vpreferably the case at the point of discharge to the amplifier andwere to merge in direct alignment with each other,,it is apparent that the latter object could be attained, if at all, with diificulty where the diameter of the valve is kept at a minimum. By my arrangement, the rams-horn conduit communicates with the valve casing at an obtuse angle illustratively of about 1.35 degrees with respect to the con duit 24, the stop screw 38 registering with peripheral groove 37 about the valve, limiting the, rotation of the valve through a corresponding obtuse angle, so that efiective lengths of arc of the valve provide the closurebetween the two conduits both in the position shown in Fig. 3 and in that shown in Fig. 4, the effective length of closing arc of the valve at the front being considerably more than 90 degrees and at the back being about degrees, in the specific embodiment shown. In all intermediate settings of the valve, the communication between the radio conduit 25 and the phonograph conduit 24 is effectively prevented, while either of these conduits alone is in communication with the amplifier. VI hen the valve is in a position midway between the extremes shown in Figs. 5 and 4, it completely shuts off ways to the amplifier.

For supporting and rotatlng the valve, I

both passageprovide a valve stem 40 extended through the top of the casing 21 and suitably connected to a boss or lug 41 integral with the valve.

The inner end of the valve stem may be burred at 42 to insure firm engagement with the valve, or the valve and stem may be rigidly connected together in any other convenient or conventional manner. The end of the valve stem which projects beyond the housing 21 is secured within a tubular sleeve 43 rising from a circular plate 44. A set screw 45 may be used to make this connection. The sleeve 43 is, in turn, rigidly fixed to a manually operable knob 46 which is used in rotating the, valve.

The manner of attaching the knob to the sleeve is not important but I find it convenient to form the knob with an integral depending socket portion 47 within which the roughened exterior of the sleeve 43 engages. The connection between the sleeve 43 and the socket 47 may be either a force fit or molded connection. Both the knob 46 and the socket 47 are slotted at 48 to accommodate and provide ready access to the set screw 45.

In order that the position of the valve 22 may be visibly indicated at all times, I pro' vide astationary dial member 49 associated with a finger 50 (Fig. 5) the latter rigid with the valve. Preferably the stationary dial member is fitted within a depression 51 on the top of the housing 21 and secured theretoby screws or similar devices 52.

To enhance the attractive appearance of the device and to facilitate operation of the same, I prefer to cant or incline the valve housing 21. to approximately the angle shown in Fig. 2. Valve 22, isthus disposed at an angle to the vertical plane of the casting 15 and the upper outer surface of the housing 22 together with the dial and knob are inclined in the direction of the front of the phonograph. The manner of graduating the dial is arbitrary, but I prefer to use suitable indicia to designate the off or neutral center position of the valve and to graduate the scale to indicate the extent to which the valve has been opened in either direction. These graduations are also associated with suitable designations, as shown.

The construction shown in Figs. 1 to 6 being mounted as shown in the drawings, the operation for phonographic purposes, is performed in the usual manner. To modulate the volume, it is merely necessary to rotate the knob 46, so that pointer 50 moves along the scale divisions appearing at the right half of Fig. 5, whereby more or less of the valve 22 will be interposed across conduit 24. In any setting of the valve, it will be seen that the rotary valve is sufficiently tight to avoid rattling or setting up vibrations of its own and, moreover, avoids theleak or interference which may attend the use of fiat or disk or spring-actuatedvalves for this purpose. It will be noted that in all settings, the valve provides an eifective seal with respect to the "conduit 23 leading to the radio receiver, eliminating any dissipation or rattling by sympathetic vibration in the receiver diaphragm.

o For radio operation, the valve is turned to the position shown in Fig. 4, in which case, it will be noted that the vibrations originating in the telephone diaphragm are amplified in the continuously diverging radio conduit 23, which conveys the vibrations in a regular continuous sweep into the throat of the amplifier. The valve 22 provides an effective seal of the radio conduit with respect to the conduit 24 or the tone arm. By the present arrangement, the eiiiciency of the amplifying horn is not cut down as it would be where even minute leakage is permitted, near the small end of the horn.

, t will be seen that by rotation of the knob 6, so that the index 50 passes along the lefthalf of the scale divisions in Fig. 5, the volume emitted by the amplifier can be delicately adjusted or controlled as desired, it being notedthat for each setting of the valve, the tightness of the closure with respect to the tone arm is maintained. Thus, the volume of sound is regulated without the need for adjusting the electrical or magnetic controls ofthe receiving set in any way.

My apparatus prov-ides a compact unit which can be easily applied to a phonograph of otherwise ordinary design by merely providing a-rectangular opening asin Fig. 1, instead of the usual" circular opening. Hereinafter, I have described, however, an embodiment of the invention applicable without any change whatsoever, to phonographs of construction now in use, in which the motorboard has a circular opening only for the mouth of the tone arm,

l\ly radio conduit and reeeiverbeing rigidly mounted; upon the phonograph independcntl y of the moving tone arm, not only dispenses with the need for substituting the telephone: receiver for the sound box and vice versa, with corresponding inconvenience, wear and rattle, but no added weight or drag is imposed" on the tone arm, which would be likely to unduly wear out the grooves. By myinvention, even it a telephone receiver of considerable weight is used, the operation of the phonograph is notimpaired and the life of the record is not shortened as compared toits use on an ordinary phonograph. Moreover,

I provide highly eiiicient amplification for radio purposes in that I avold the leak near' the throat of the amplifier which may occur particularly at the swivel mount of the tone arm, where suchtone arnr serves to convey the vibrations from the telephone receiver to the amplifier throat, or at the radio inlet to the amplifier, where the radio receiver delivers past a flap valve in the lateral wall ofthe amplifier-and near-the throat thereof.

In certain oittheclaims I have defined the especially applicable to phonographs already in use, the motorboa -d of which has a circular aperture 62 for the mouth of a tone arm only. The neck of the amplifier in such machines is secured directly below opening 62 to the motorboard- 61. Inv this instance, I employ acasting 63 alsopreterahly of generally rectangular shape, but supportedupon theupper suri'aceot the motorboard instead ott'being countersunk in an opening therein.

Casting 633 is formed with radio conduits 65 and phonograph conduit 64. of the same general shape as the conduits 23 and 24, and

communicating respectively with the tonearm 66 and a lZGlQPllOHO16661V6P67. These conduits areadapted to be selectively placed in communication with. the amplifier 60. byturning a control valve 68 similar to the valve 21 and similarly controlled by anexterior knob 69 connected to thestem 70 of thevalve.

The appearance of the selector unit maybe ing end of the arm is shortened to compen-- sate for the height of the casting 63 above the motorboard.

It will be understood that while in many cases, it is preferred to mountthe tonearm.

at one sidcof the. valve. knob andthe radio receiver at thezopposrte side of the valve knob,

my invention is not limited: to such arrangement, but the two CODClLHlJS' may extend at angles relative to each other. For instance,

in a phonograph of the construction in which the tone arm 1S11101111f6Cl at the corner of the.

motorboard, it would be preferred to applythe valve knob at the corner and the radio and phonograph conduits at right angles to:' each other, extending one generally alon gthe rear and the other generally along the side wall of the phonograph cabinet. It will also be understood that the phonograph and, the radioscondui-ts may extend onein a: plane lower than the other, both. in; the same general dire-ctionor at an angle relative to each other, the two conduits controlled, it desired, from a single valve of length to extend across:

both said conduits.

Obviously, if desired, I could employ in stead of'thesingle control: valve, separate valves for the radio and phonograph con.- duits, but the former construction; is pre- 'l erreda V In Fig. 8' is illustrated a further modified:

form of construction entirely concealed in the phonograph. In this instance, the motorboard -is formed with an opening 81: encircled by a socket member 82 which provides the usual swiveledmount for a tone arm 83,

the arrangement of the tone arm above the opening being entirely-conventional. A substantially globular valve casing 84 is screwed or otherwise secured to the underface of the motorboard and formed with. openings 8586 registering respectively with the opening 8-1 and with the neck 87 of the amplifier, the throat of the lattersecured to the lower end of casing 84. Valve-casing- 84. is also formed with lateral opening88- registering with the enlarged end of a radio conduit S9 in a. casting 90 secured thereagainst by afiange 9a and-secured tothe underface-ot the motorboard.

a telephone receiver 91:. Gonduitx89 may be of the same general sh'apeas the conduits-65 The conduit 89 serves to place thevalve casing in commumcataon-with' way 97 disposed at right angles to the passage-way 96 cooperates with this passageway to establish communication between conduit 89 and the amplifier 87 when the valve is turned at right angles to the position shown in Fig. 8. The operating means itor this valve is indicated merely in dotted lines as comprising a stem 98 and knob 99. For convenient operation of the valve, it is desirable that the stem 98 be extended through a side wall of the machine and operated from the exterior of themachine by the knob. The receiver 91 instead of being concealed within the motor casing of the machine may be connected to the conduit 89 through the motorboard, as indicated in dotted lines in this figure.

.While I have shown the invention applied in a construction embodyingbut two conduits leading to the amplifier throat, one from the phonograph repro ducer and the other from the telephone reproducer, it will be understood that the invention could be carried forward to embody three or more conduits embodying a plurality of radio conduits, or a plurality of phonograph conduits. "Iclaim:

1. In apparatus of the character described,

'in combination, a phonograph amplifier having a throat, a tonearm for communication with said throat, a fixed conduit of generally rams-horn shape having its wider end delivering into said throat and adapted for mounting a telephone receiver at its restricted end, said conduit having substantially Y extending lengthwise thereof to block communication with the tone arm. I

2. The combination of a tone arm and a fixed amplifier ofa pair of fixed conduits, one

of which is adapted to connect the tone arm and amplifier and the other of which is adapted to connect a telephone receiver and the amplifier, and a common control means for optionally placing either one of said conduits out of communication with the amplifier.

3, The combination which includes a tone arm and an amplifier, of a member formed with a plurality of passage-ways therein, one of which is adapted to connect the tone arm and the amplifier and the other of which'is adapted to connect the amplifier with a telephone receiver, said last-mentioned passageway being of generally ra-ms-horn shape and control means for optionally placing either of said passage ways in communication with the amplifier.

41:. The combination which includes a casing, a .tone arm and an amplifier, of a unit mounted on top of the casing and formed with a pair of passage-ways therein, one of which is adapted to connect the tone arm and the amplifier and the other of which is adapted to connect a telephone receiver with the amplifier, said last mentioned passage-way being relatively long and of continuously increasing diameter toward its delivery end, and av common control means for optionally placing eitherof said passage-ways in communication with the amplifier.

5. The combination set forth in claim 4 in which the control means when set for telephone operation, establishes a relatively sound-tight connection from the telephone passage-way to the amplifier. 6. The combination which includes a casing, atone arm and an'amplifier, of a fixed unit mounted at the exterior of the casing and formed with a pair of passage-ways therein, one of which is adapted to connect the tone arm and the amplifier and the other of which is adapted to connect a telephone receiver and the amplifier, and a valve manually operable to place either of said passage-ways in communication with the amplifier, said valve in either setting afiording an entrance to the throat of the amplifier of thefull area of said throat.

7.-,The combination which includes a cabinet,a tone 'arm and an amplifier of a removablefixedunit mounted at the exterior of the cabinet, formed with a pair of passage-ways therein, one of which is adapted to connect the tone arm and the amplifier, and the other o1 which is adapted to connect a telephone receiver and the amplifier, said last mentioned passage-way being relatively long and of continuously increasing diameter toward its delivery end and a valve manually operable toplace either of said passage-ways in communication with the amplifier.

8. The combination which includes a tone arm and an amplifier, a motorboard therebetween, of a removable unit fixed upon the top of said motor-board, formed with a pair of passageways therein, one of which is adapted to connect the tone arm and the amplifier and the other of which is adapted to connect a telephone receiver with the amplifier, and a cylindrical valvemanually operable to throttle the passage from the tone arm to the amplifier, for varying the volume, and in one position to cut off communication between the tone arm and the amplifier for operation of the telephone.

9. The combination which includes a motor-board, an amplifier therein, of a fixed unit tac-hable to the cabinet and formed with a pair of passage-ways therein, both having inlets above the cabinet, one of which is adapted to connect the tone arm and the amplifier and the other. of which is adapted to connect a telephone receiver and the amplifier, said passage-ways uniting in a valve chamber in advance of-their communication with the amplifier, and a common control valve in said chamber.

11. The combination which includes a cabinet having a motorboard, an amplifier ther in, of a unit attachable on top of said motorbcard and formed with a pair of passageways therein, one of which is adapted to connect a tone arm and tl e amplifier, and the other of which is adapted to connect a telephone receiver to the amplifier, and a rotatable controlinie-mber for optionally placing either of said passages in partially throttled or completely open communication with the amplifier.

12. The combination which includes a cabinet and an amplifier therein, of a unit attachable thereto and formed with a pair of passage-ways therein, one of which is adapted toconnect the tone arm and the amplifier and the other of which is adapted to connect a telephone receiver and the amplifier, a rotatable control member for variably throttled or completely open communication between the unit andthe amplifier, a knob on the exterior of said unit for rotating said member, and indicating means associatedwith the knob, comprising .a finger carried by the knob anda fixed dial coac ting with the finger.

13. An article of manufacture comprising acasting having a pair of passage-ways therein leading from one face thereof and merging at the opposite side to connect at said merging part into the amplifier of a phonograph for operative relation of a tone varm'anda telephone receiver mounted at the nonmerging ends of the respective passage- .Ways, and a control valve member by which the cross-sectional area of thephonograph passage-way may be varied, said valve in one posltion closing the passage-way to the tone arm and establishing communication from the telephone receiver to the amplifier.

14. An article of manufacture comprising a casting having a pair of passage-ways therein adapted to connect the small end of the amplifier of a phonograph in operative relation with a tone arm and with a telephone receiver respectively, and .a common control member for optionally connecting either passage to deliver into the small end. of the amplifier, said control member comprising a valve having limited rotary movement in the casting and constructed and arranged in manner such that when the tone arm is in communication with the amplifier, the tone receiver is sealed therefrom and vice versa.

15. In a phonograph construction, in combination, a structure having a pair of passage-ways therein, for connection to the small end of the amplifier, a telephone re ceiver at the inletend of one of said passageways, and a swivel structure carried by the inlet of the other said passage-Way to mount a tone arm, said inlets both at the upper face of said structure.

16. In a phonograph construction, in combination, a structure having a pair of passage-ways therein, for connection to :the throat of the amplifier, means at the end of one passage-way providing a swiveled mount for a tone arm carried by said structure,

and means at the end of the other passage-v way providing a mount'for a telephone receiver, said telephone receiver mount at'the upper face of the structure.

17. In an apparatus of the character described, in combination, an amplifier, having a throat, a sound reproducer, a conduit conneeted to said sound reproducer, said conduit including a cylindrical valve with an open bottom communicating with said throat and having an opening in one side thereof adapted to establish communication between said sound reproducer and said amplifier throat.

18. In apparatus of the character described, in combination, an amplifier, a plurality of sound reproducers, separate conduits connecting each of said sound reproducers with the small end of said amplifier,

casing communicating with the amplifier, a

rotary valve therein to-communicate with either of said passages, and means limiting the rotation of said valve. through an angle substantially equal tosaid obtuse angle, so that in all positions of said valve, communication between the two conduits is prevented.

20. .Thecombinationwith a phonograph. including a'motorboard'having an opening therein'and an amplifier registering with and directly connected to the underface of the motorboard about said opening, of a separable structure supported upon the motorboard, and including a tone arm and a tele phone receiver, said structure having a pair of passage-ways therein, connected respectively with the tone arm and thereceiver, and both communicating with the amplifier, and a common control member for both passageways mounted in the structure directly above the opening in the motorboard.

21. In combination, a cabinet, a fixed amplifying horn therein, a phonograph tone arm, a telephonic speaker above the cabinet and having fixed position relative to the horn, and means interposed between said phonograph tone arm and said horn on the one hand and between said telephonic speaker and said horn on the other hand, for selectively connecting either the tone arm or the telephonic speaker to deliver into the small end of said amplifying horn.

22. In combination, a motorboard, an amplifying horn, a phonograph tone arm, a telephonic speaker and stationary means on top of the motorboard and interposed between said tone arm and amplifying horn on the one hand and between said telephonic speaker and amplifying horn on the other hand for selectively connecting either the one or the other to deliver into the small end of said amplifying horn a wave front of the area of said small end. v

23. In combination, a motorboard, an amplifying horn, a phonograph tone arm, a telephonic speaker, and means fixed on top of the motorboard and interposed between said tone arm and motorboard on the one hand and between said telephonic speaker and motorboard on the other hand for selectively connecting either the one or the other with said horn.

24. In combination, a motorboard, an amplifying horn, a phonograph tone arm, a telephonic speaker and a unit on top of said motorboard and fixedly interposed between said tone arm and amplifying horn on the one hand and between said telephonic speaker and amplifying horn on the other hand, said stationary unit being provided with means for selectively placing into acoustic communication either the tone arm or the telephonic speaker to deliver into the small end of said amplifying horn.

In combination, an amplifying horn, a phonograph tone arm, a telephonic acoustic passage, and means interposed between said amplifying horn and said tone arm and passage, wherehy the extent of acoustic communication between either the tone arm or the passage may be varied while communication between the tone arm and the acoustic passage is at all times closed.

26. In combination, a stationary amplifying horn, a motorboard, a phonograph tone arm, a telephonic speaker, and means fixedly mounted on top of the motorboard and carrying said tone arm and said speaker for selectively connecting either the one or the other with said horn.

Signed at New York city in the county of New York and State of New York this 17th day of May, A. D. 1924.

MAXIMILIAN IVEIL.

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