US1489413A - Talking-machine reproducer - Google Patents

Description

C. H. ALLEN ET AL TVALKING MACHINE REIRODUCER AApril s 1924.

Orignl Filled Aug. 25 1920 2f zz i a l! :ks

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To all whom t may concern:

Patented Apr. 8, 1924.

UNITED VSTATES PATENT OFFICE.

CHARLES H. .ALLEN AND CHARLES A.. MOORE, OF` CHICAGO, ILLINOIS.k

TALKIN G-MACHIN E REPRODUCER.

Application filed August 25, 1920, Serial No. 405,827.

Be it known that we, CHARLEsH. ALLEN and CHARLEs A. MOORE, Icitizens of thel United States, and residents of the city of Chicago, in the county of Cook and State of illinois, have invented certain new and use` ful Improvements in a Talking-Machine Reproducer; and wedo hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the numerals of reference marked thereon, which form a part of this specification.

This invention relates to talking machines and more particularly to the reproducers thereof, with a View to improving the tone qualities and the adaptability of the machine. Hitherto it has been usual in talkingmachine construction to provide a diaphragm which covers the end of a tube leading toa horn, whereby sound waves are transferred to the horn and therein amplilied. y In the vibration of such a diaphragm two sets of air waves are set into motion, one on each side of the diaphragm, but it will be seen that only one set of air waves is utilized, namely, those on that side of the diaphragm which pass into the tube or amplifying horn, the duplicate set of air waves generated on the opposite side of the diaphragm being. dissipated in the air and therefore lost on account of their not being amplified. It willV be seen, therefore, that only a maximum of fifty per cent of all the air waves generated. could be utilized in the reproduction of sound.

One of the objects of this invention, therefore, is the utilization of a maximum amount of the sound waves generated by a vibrating diaphragm by leadinga sound conducting tube from each side thereof. f

Hitherto most-of the reproducers used in phonographs were adapted to reproduce only one particular sort of vibrations from the record or disk. As is well known, some ofthe records now in use employ indentations for the transmission of sound which are in a horizontal plane or are wavy lines in the surfaceof the disk and other records employ indentations which are made in a vertical plane in the disk and are undulatory. In other words, the production of' sound in some records is accomplished by means of vibrating 'the ypoint of the needle in a horizontal or transverse plane, and in other records the point of the needle is viitenewed Aug-ust 22,1923. y

` brated in a vertical'plane. Now, in vorder to `use both types of records on one machine,

it vhas been hithertol necessary to shift they point of the needle through an angle of approximately degrees in order to attain the full beneiit from the vibrations which were produced in planes 90 degrees apart.

Another object of' this invention, therefore, is to produce a phonograph reproducer which will reproduce sound from both records which ,have their vibrational impressions in horizontal yand in vertical planes without any shift of the needle or of the reproducer.

A still further object of this invention is the provision of an improved form of reproducer whereby all the vibrations from the record or disk are transmitted directlyto the diaphragm, but'without imposing any undue strainV on the diaphragm due to the weight of the reproducer or other causes.

A further important object of this invention is to provide a phonograph reproducer which can bev readily taken apart and which can be removed from the remainder of the reproducer assembly with a minimum of time and edort. p

Other and further important objects of this invention will be apparent from the disclosures in the speciiication and drawings. The invention (in a preferred form) is illustrated in the drawings and hereinafter `more fully described.

In the drawings: Figure l is a side elevation, partly in section, of our improved formof phonograph reproducer shown as applied to a disk record. r y l FigureQ is a rear elevation of the same, thJ tube to the amplifying horn being omitte ylligure 3 is a bottom plan'view of the same. y `Figure 4 is a sectional view of the reproducer and of the tube leading to they amplifying horn showing the method of attaching the reproducer to the tube.

, Figure 5 is a sectional view taken on the line 5-5 of Figure 4, looking lin the direction indicated by the arrows. "Figure 6 yis a detail view showing the method'of attaching the diaphragm to the pivoted needle holder. 1

. i VAs' shown on the drawings:

from the reproducer to the amplifyin horn. However, Vin this construction 'the tu e terminates in two branches 12 and 14, which are made in the shape of a U and the ends of which are adapted to itinto corresponding tubular portions 16 and 18 in the reproducer member. It is to be noted that the sum of the sectional areas of the tubes 12 Aand 14 is equal to the area of the horn 10 at the point of -junction therewith and from said point orn junction the horn gradually expands. This construction is a material factor in adding to the tonal qualities olf-the device. These tubular portions 16 and .18 are bent toward each other in the reproducer and terminate in chambers 2O and 22 respectively, one on each side of a diaphragm 24 located in the middle of the reproducen This diaphragm 24 is held in place by an ordinary packing v26, through which passes screws 27 for holding the reproducer and diaphragm in assembled condition.

Attached to the diaphragm 24 by .means of a nut 28 is a pin or light boltBO, which extends downwardly through the chamber and lower tube '18 and out through a small aperture 32 in the reproducer. rfhe bolt is screw-'threaded at its lend and adapted to screw into a needle-holding member 34, which ispivoted at 36 to two downwardly extendinglugs 88, which are integral with 'the bottom plate of -the reproducer.

The needle holding member 34 is provided with an ordinary knurled screw 40 for thepurpose of holding the needle 42in position. Adjustably held in place on the bottom of the reproducer by Lmeans of a screw 44, is a lea-f spring-46, which rests upon 'the top of the needle holding member 34 and coacts therewith to resiliently vsupport the same and thereby act to take part of the weight of the reproducing member vfrom the diaphragm.

The operation is asfollows:

The needle 42 is :placed in contact with the record or disk and the record accordingly revolved, whereupon the needle will v be vibrated and such vibration will be transmitted to the diaphragm 24 through the bar or pin' 30. Sound waves, upon being set up by thefvibration of the diaphragm v24, will be transmitted in both directions through they tubes 16 and 18 and through the U-.s'haped member 12 and 14 into the Vmain tube 10, 7from which-they are delivered Ato the amplifying horn. It will be .seen that in this manner no sound waves are dissipated in the air, all of them -which are generated by the motion of the diaphragm beingretained in the reproducer and transmitted inthei`r full volume to the amplifying horn by means of the tubes 16,118, 12, 14 and '10..

yIt will be seen that the needle 42 is so mounted that vibrationsof its point in either p a horizontal or a vertic'a-ljplane' will betra'nsmitted to the diaphragm 24 with equal ease regardless of the plane in which the depressions in the record are produced. Any Vibrations in a vertical plane will be trans- 'mittedin Vertical waves-directly through the needle 42, the needle holding member 34 and the bar 30 to the diaphragm 24. Likewise vibrations in a horizontal plane Will be followed by the point of the needle 42, making it vibrate in a horizontal plane. These vibrations will be along an arc loi? that circle which has its-center at the pivot point 36 and will accordingly be transmitted through the bar orpin 30 to the diaphragm 24 in -practically the same manner as vibrations resulting irom-depressions Vin the record which have their wave lines ina horizontal plane.

It will further be noted that the weight of the reproducer, which would ordinarily be entirely supported by the diaphragm 24, is taken up by the spring 46, which thereby Vsupports the reproducer through Vthe needle holding member 34. Should the tension in the spring 46 become lessened, .it can easily 'be adjusted by means of therscrew 44, thereby taking all or partofthe weight of the reproducer, accordingly as desired.

It -will be seen that herein is provided fa phonograph reproducer which is Vadapted, to reproduce notesfrom records in which .the sounds were recorded by means otarecording needle, the Vpoint of which vibrated .in either a horizontal Y or a vertical plane. Usually a record which has had its notes recorded thereon by means of a recorder thepoint of which vibrates in a horizontal plane cannot have its sound reproduced by means of a reproducen whose point will vibrate in only a vertical plane, and it therefore becomes necessary to shift the-reproducingvneedle through an--arc or angle of vapproxi-mately 90 degrees in order to accommodate the needle to the vibrations which were recorded in the other disk or record. It will further be seen that the entire weight of the reproducer and part of the weight of the horn 10 can be supported'by mea-ns of the spring 46, the whole or-part of the weight of these partsbeing taken oil `the diaphragm, which would otherwisesupport them, according-to the tension in-the spring which is adjusted by mea-ns of the screw 44 according to the will of the operator. It will likewise be observedy that all of the sound waves propagated from 'the diaphragm are retained within the tubes 16 and 18 and'transmitted through the tubes 12, 1`41and 10 into the amplifying horn, which is not the case with Iany of the reproducersn'ow on the market, in which at least half ofthe sound waves produced are dissipated in the air and wasted on'aceount of the fact that the sound carrying tubeis located on onlyone side of the diaphragm,

` whereby a maximum of only 50 per cent of the sound Waves pro agated by the diaphragm can be taken a vantage of.

We are aware that numerous details of construction may be varied through a wide range without departing from the principles of this invention, and we therefore do not purpose limiting the patent granted otherwise than necessitated by the prior art.

We claim as our invention:

In a phonograph reproducer, a pivot parallel to the plane of the record and to the direction of travel thereof, an arm on said pivot, the arm being approximately parallel to the plane of the record and at right angles to the direction of travel of the record, a needle holder rigid with said arm at right angles to the plane of the record, and a connection for said arm to the diaphragm in line with the needle holder, the distance from the record to the arm when in position to bring the needle against the record being approximately equal to the distance from said pivot to the needle holder, whereby records of the undulating type and records of the sinuous type can be played with equal effectiveness.

In testimony whereof, we have hereunto subscribed our names in the presence of two subscribing witnesses.

CHARLES H. ALLEN. CHARLES A. MOORE.

Witnesses:

CARLTON HILL, EARL M. HARDINE.

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